机械工程英语part2 1-7单元

Part02 Unit01 Computer Technologies Introduction 导言

The central and essential ingredient of CAD/CAM is the digital computer. CAD/CAM最重要的组成部分是数字计算机。

Its inherent speed and storage capacity have made it possible to achieve the advances is image processing, realtime process control, and a multitude of other important functions that are simply too complex and time-consuming to perform manually.

数字计算机固有的速度及其存储能力使得CAD/CAM进行图像处理，实时控制以及其他许多重要功能若手工操作复杂又耗时能简单得进行成为可能。

To understand CAD/CAM, it is important to be familiar with the concepts and technoloty of the digital computer. 想要掌握CAD/CAM，熟悉数字计算机技术及理论是非常重要的。

The modern digital computer is an electronic machine that can perform mathematical and logical calculations and data processing functions in accordance with a predetermined program of instructions.

现代数字计算机是一种可以根据预先设定的程序指令进行逻辑数据运算以及数据处理功能的电子仪器。 The computer itself is referred to as hardware, whereas the various programs are referred to as software. 计算机本身称为硬件,而各种各样的程序都被称为软件。

There are three basic hardware components of a general-purpose digital computer: 通用的数字计算机有如下三个基本组成设备：

●Central processing unit (CPU) 中央处理单元(CPU) ●Memory 记忆单元

●Input/output (I/O) section 输入/输出单元

The relationship of these three components is illustrate in Fig.1.1. The central processing unit is often considered to consist of two subsections: a control unit and an arithmetic-logic unit (ALU).

三个设备的相关关系如图1.1所示。中央处理单元往往被认为是由两个子单元组成：控制单元和数据逻辑单元（ALU）。 The control unit coordinates the operations of all the other components. It controls the input and output of information between the computer and the outside world through the I/O section.

控制单元协调其他所有组件的操作，控制单元通过I/O部分控制计算机与外部环境信息的输入与输出。

Synchronizes the transference of the signals between the various sections of the computer, and command the other sections in the performance of their functions. The arithmetic-logic unit carries out the arithmetic and logic manipulations of data . It adds ,substracts, multiplies, divides, and compares numbers according to programmed instructions.

指挥其他部分执行各自的功能。数字逻辑单元控制数据的运算和逻辑操作。根据程序指令进行加，减，乘，除以及数字的比较。

The memory of the computer is the storage unit .The data stored in this section are arranged in the form of words which can be conveniently transferred to the ALU or I/O section for processing.

计算机的记忆单元是计算机的存储单元，数据以方便传输至ALU单元或者I/O部分并进行处理的语音形式存储在这一部分。 Finally, the input/output provides the means for the computer to communicate with the external world. This communication is accomplished through peripheral equipment such as readers,printers,and process interface devices.

最后，输入/输出单元提供计算机与外部设备交互的方式。这一交互是通过周边设备如读取器、打印机和过程控制接口设备实现的。

The computer may also connected to external storage units(e.g.tapes,didks,etc.) through the I/O section of the computer. 计算机也可以通过计算机的I/O部分连接外部存储单元（如磁带，磁盘等）。

The software consists of the program and instructions stored in memory and in external storage units. It is the software that assigns the various functions which the user desires the system to accomplish to the computer. The useful of the computer's memory can be easily changed .and therefore different programs can be placed into memory, the digital computer can be used for a wide variety of applications.

软件包括存储在内部和外部存储单元的程序和指令。软件分配执行各种各样用户希望计算机去执行的功能。有用的计算机内存可以很容易改变并且因此不同的程序可以放置进内存,数字计算机可以广泛应用于各种各样不同的场合。

Regardless of the application, the computer executes the program through its ability to manipulate data and numbers in their most elementary form. The data and numbers are represented in the computer by electrical signals which can take one of two alternative states. This form of representation is called the binary system. The more familiar decimal number system and a whole host of software languages can utilize the binary system to permit communication between computers and human beings.

不管应用于哪种场合，计算机总是通过计算机本身最基本的操作数据和编号形式执行程序。在计算机中数据及编号是通过在两种不同状态的电信号中选择一种状态表示的。这种形式的表现被称为二进制系统。更熟悉的十进制系统和许多软件

语言可以利用二进制允许计算机和人之间的交互。 Central Processing Unit(CPU) 中央控制单元

The central processing unit(CPU) regulates the operation of all system components and performs the arithmetic and logical operations on the data. To accomplish these functions,the CPU consists of two operating units: ●Control unit

●Arithmetic-logic unit(ALU)

中央控制单元（CPU）的功能是控制所有系统部件的运行和对数据进行数字的或是逻辑的操作。为了完成上述功能，CPU由以下两个单元组成: ●控制单元 ●数字逻辑单元

The control unit coordinates the various operations specified by the program instructions. These operations include receiving data which enter the computer and deciding how and when the data should be processed.The control unit directs the operation of the arithmetic-logic unit, It sends data to the ALU and tells the ALU what functions to perform on the data and where to store the results. The capability of the control unit to accomplish these operations is provided by a set of instructions called an executive program which is stored in memory.

控制单元通过程序指令来协调大量的特种操作，这些操作包括接受输入计算机的数据，并决定何时和以何种方法来处理这些数据。控制单元能指挥数字逻辑单元的操作，他把数据发送给ALU来告诉ALU根据这些数据该运行什么功能，并且在哪里把结果存储下来。控制单元完成上述操作的能力基于其安装了一个具有储存与记忆功能的总控程序机构。

The arithmetic-logic unit performs opertaions such as addition, substractions, and comparisons. These operations are carried out on data in binary form. The logic section can also be used to alter the sequence in which instructions are executed when certain conditions are indicated and to perform other functions, such as editing and masking data for arithmetic operations.

数字逻辑单元运行诸如加减比较之类的操作。这些操作是根据数据以二进制的形式表现出来的。在指示了确定的条件下，逻辑部也可以用来改变命令执行的次序。此外，逻辑部分还具有在算术过程中编辑或清除数据等功能。

Both the control unit and the arithmetic-logic unit perform their functions by utilizing registers. Computer registers are small memory devices that can receive, hold, and transfer data. Each register consists of binary cells to hold bits of data. The number of bits in the register establishes the word length with which the computer is capable of handling. The number of bits per word can be as few as 4(early microcomputer) or as many as 64(large scientific computers).

控制单元和数字逻辑单元都是得用寄存器来完成他们的功能的，计算机寄存器是一个可以接收短暂存储，转移数据的小记忆装置。每个寄存器内包含有二进制小单元以来暂存二进制数据。根据计算机能力的不同，寄存器能建立出相应的字节数的字长。每个词的字节数从4(早期微型计算机)到64(大型科研计算机)不等。 Computer Programming Languages 计算机程序语言

The binary number system could be used to represent any decimal number, alphabetic letter, or other common symblo.Data and instructions are communicated to the computer in the form of binary words. In executing a program. the computer interprets the configuration of bits as an instruction to perform electronic operations such as add,subtract, load into memory, and so forth. The sequence of these binary-coded instructions defines the set of calculations and data manipulations by which the computer executes program.

二进制数字系统可以用于表示任意的十进制数据，字，或者其他相类似的代表性数据并且指令是以二进制的形式与计算机进行连接。在执行一个程序时，一个指令进行电子操作,如加、减、加载内存,等等时计算机就会翻译指令的字节结构。这些二进制编码指令的序列定义了计算和数据操纵是由计算机的哪条程序执行。

The binary-coded instructions that computers can understand are called machine language.Unfortunately,binary-coded instructions and data are very difficult for human programers to read or wirte. Also, different machines use different machine languages. To facilitate the task of computer programming, higer-level languages are available which can be learned with relative ease by human beings. In all there are three levels of computer programming languages: ●Machine languages ●Assembly languages

●Procedure-oriented(high-level) languages.

计算机能识别的二进制编码指令叫机器语言，不幸的是，二进制编码指令和数据，人类程序员是难以去读和写的。另外，不同的机器应用不同的程序语言，为使计算机编程任务变得简单，高级语言可供选择,可以较容易地学习的人。总共有三种不同计算机程序语言。 ●机器语言 ●汇编语言

●面象过程语言（高级语言）

Machine and Assembly languages 机器与汇编语言

The language used by the computer is called machine language. It is written in binary, with each instruction containing an operation code and an operand. The operand might be a memory address, a device address, or data. In machine language programming, storage locations are designated for the program and data, and these are used throughout the programming to refer to specific data or program steps. In addition, the programmer must be familiar with the specific computer system since machine language instructions are different for each computer. Programming in machine language is tedious, complicated, and time-consuming. To alleviate the difficulties in writing programs in binary, symbolic languages have been developed which substitute an English-like mnemonics for each binary instruction. Mnemonics are easier to be remembered than binary, so they help speeding up the programming the process. A language consisting of mnemonic instructions is called an assembly language.

计算机运用的语言叫机器语言。运用二进制进行编写。每个指令都包含有一个操作码和操作数。操作数可以是一个内存地址，一个设备地址或者是数据。在机械语言程序中，存储单元指定程序和数据，并且这种指定应用于整个程序以指向特定的数据或者程序步。此外，每个程序员必须熟悉特定的计算机系统因为每种计算机的机器语言指令是彼此不同的。机器语言编程是乏味的,复杂、而且耗费时间的。为了减轻在编写二进制程序的困难，符号语言已经开发出一种每一个英语助记符代替二进制指令。助记符比起二进制是比较容易记忆的，所以它们帮助提高程序的处理速度。包含有助词符指令的语言叫做汇编语言。

Assembly languages are considered to be low-level languages. The programmer must be very knowledgeable about the computer and equipment being programmed. Low-level languages are the most efficient in terms of fast execution on the computer, but there are obvious difficulties for the programmer in writing large programs for various applications using different computers. 汇编语言也被认为是低级语言，程序员必须对计算机语言及被编制设备有相当的了解。在计算机中低级语言能最有效的快速的执行。但是让程序员运用不同的计算机为各种各样的场合编写大量的程序有明显的难度。

Assembly language programs must be converted into machine language before the computer can execute them. The conversion is carried out by a program called an assembler. The assembler takes the assembly language program. performs the neccessary conversions, and produces two new programs ; the machine language version and an assembly listing. The assembly listing shows mnemonic instructions and their associated machine laguage equivalents.and any erros the original assembly language program may have contained.

在计算机能运行汇编语言程序之前，汇编语言程序必须转换为相应的机器语言，一种叫汇编器的程序完成这一转换。汇编器将汇编语言程序进行必要的转换，并产生两种新的程序：机器语言版本和汇编列表。汇编列表显示与机器语言相对应的助词符。并且任何原始的汇编语言程序错误都会包含在其中。 High-level Language 高级语言

Assembly languages are machine oriented. High-level languages, by constrast. are procedure oriented. They are to a large extent independent of the computer on which they are used. This means that a program written on one computer can be run on a different computer without any significant modifications to the program.

汇编语言是面向机器，高级语言，相反地，是面向过程的。高级语言在计算机上运用时有很大的独立性。这意味着一个程序在一台计算机上编写可在不同计算机上运行而不用对程序进行大的修改。

High-level languages consist of English-like statements and traditional mathematical symbols. Each high-level statement is equivalent to many instructions in machine language.

高级语言由英语式声明和传统的数字符号组成。每一个高级声明相当于机器语言中的许多指令。

The advantage of high-level languages is that it is not necessary for the programmer to be familiar with the machine language. The program is written as an English-like algorithm to solve a problem. Like assembler languages, high-level languages must also be converted into machine code. This is accomplished by a special program called a compiler. The computer takes the high-level program, and converts it into a lower-level code. such as the machine language. If there are any statement errors in the program(e.g.misspelled words), error messages are printed in a special program listing by the compiler.

高级语言的优点在于程序员不必对机器语言很熟悉，程序写成英语算法的形式解决相应问题。像汇编语言一样，高级语言必须转换成机器代码。这一功能的实现是通过一种特殊的叫编译器的程序完成的。计算机接收高级程序并将它转换成低级代码，如机器语言。如果在程序中有任何的声明错误（如字母的拼写错误），编译器上都会将错误信息打印在一个特殊的程序列表中。

There are many different high-level languages, Some of the most commonly used of there are BASIC,COBOL,FORTRAN,APL,RPG,PL/1,and PASCAL.

有许多不同的高级语言,最常用的一些有BASIC,COBOL,FORTRAN,APL,RPG,PL/1,and PASCAL。 Computer Process Interfacing 计算机程序接口

To be useful, the computer must be capable of communicating with its environment. In a data processing system, this

communication is accomplished by various input/output devices such as card readers, printers, and CRT consoles. In computer-aided manufactring, the environment of the computer includes not only these devices but also includes one or more manufacturing processes.Functioning as a process control system, the computer must be capable of sensing the important process variables from the operation and providing the necessary responses to maintain effective control over the process control system.

为了使信息有用,计算机必须有与周围环境交互的能力。在一个数据程序系统中，这一交互功能是通过各种各样的输入/输出设置完成的，如读卡器，打印机，以及CRT控制台。在计算机辅助制造中，计算机周边环境不仅包括这些设备还包括一或者更多的制造程序。如工艺控制系统功能，计算机就必须具备有从操作中感应重要变量的能力，并通过工艺控制系统提供必要的响应去保持有效的控制。

(1)Manufacturing process data. The data that must be communicated between the manufacturing process and the computer. These data can be clasified into three categories: ●Continuous analog signals ●Discrete binary data ●Pulse data

（1）制造过程数据：制造过程与计算机之间的数据必须能够相互交流。这些数据可以定义成下列三种分类： ●连续模拟信号 ●离散二进制信号 ●脉冲信号

Continuous analog data can be represented by a variable that assumes a continuum of values over time.During the manufacturing process cycle, it remains uniterrupted, and the values it can assume are restricted to a finite range.Examples of analog variables include temperature, pressure,liquid flow rate, and velocity.Each of these phenomena are continuous functions over time and are capable of taking on all infinite number of values in a certain range. The number of values permitted is a function of the ability of measuring instruments to distinguish between different signal levels.

连续模拟的数据可以表示为一个变量,即假设连续统一的值，经过制造过程循环，信号保持不间断，并且信号值可以假设被限制在一个有限的范围内。模拟信号的例子包括温度，压力，液体流速，以及速度。每一种现象都是随时间连续的函数。并且在一定范围内可取所有无数的值。允许的数值大小是一个函数计量器具区分不同信号的水平能力的大小。

Discrete binary data can take on either of two possible values, such as on and off, or open and closed.Switches, motors, valves, and lights are all devies whose status at any time may be a binary function.Binary data are represented in electronic digital systems as typically one of two voltage levels whose values depend on the specific devices that make up the system.Typical voltage levels are 0 and +5V.

离散二进制数据可处于两种不同的值。如开和关，打开与关闭，开关，马达，阀门，以及灯这些设备的状态在任何时候都是二元函数。二进制数据都是用电数字系统表示的，通常两个电压水平的那个值依赖于特定的设备组成的系统,典型的电压水平是0和+ 5V。

Pulse data consist of a train of pulsed electrical signals from devices called pulse generators.The pulse train can be used to drive devices such as stepping motors.The magnitude of each pulse is fixed; the magnitude of the pulse train is the number of pulses it contains.Since the number of pulses in a series can be counted over a period of time, that number can be represented as digital data. Conversely, digital data can be used to produce a pulse train of a given magnitude.

脉冲数据是由一系列脉冲发生器设备产生的脉冲电子信号组成。脉冲链可以用于驱动设备,如步进电机，每个脉冲的大小都是固定的，脉冲链的大小取决于包含的脉冲的数量。从一个周期时间内脉冲一系列的脉冲数可以计算，计算的脉冲数可用数字数据进行表示。相反地，通过数字数据可以产生给定大小的脉冲链。

(2)System interpretation of process data. The three categories of manufacturing process data must be capable of interacting with the computer. For monitoring the process, input data must be entered into the computer. For controlling the process, output data must be generated by the computer and converted into signals understandable by the manufacturing process. There are six catagories of computer-process interface representing the inputs and outputs for the three types of process data. There categories are: ◆Analog to digital ◆Contact input ◆Digital to analog ◆Contact output ◆Pulse generators

(2)系统的过程数据解释：三大类的制造过程数据必须具备与计算机交互的能力。监测的过程中，数据必须输入计算机中。控制的过程中，输出数据必须由电脑产生并转换成能被制造过程识别的信号。在此过程中，有六大类计算机过程接口描述了三大类型过程数据的输入与输出。分类如下： ◆模拟到数字转换

◆ 接触输入端 ◆数字到模拟转换 ◆ 接触输出端 ◆脉冲发生器

Analog-to-digital interfacing involves transforming real-valued signals into digital representations of their magnitude. A number of different steps must be accomplished to affect this conversion process. These steps involve the following hardware:

模拟数字的接口包含将实信号转变成相应大小的数字形式。许多不同的步骤必须做到影响这转换过程.这些步骤包含以下硬件：

1.Transducers, which convert a measurable process characteristic(flow rate, temperature, process,etc.) into electrical voltage levels corresponding in magnitude to the state of the characteristic of the process measured. A thermocouple is an example of a device in this category. It converts temperature into a small voltage level.

1.传感器:传感器将测量的过程特征（如流速，温度，位移等）转换成与相应过程测量状态相符合的电压值。一个热偶在这一类接口中是一种典型的装置。它将温度转换成低电压。

2.Signal conditioners, which filter random electrical noise and smooth the analog signal emanating from transducing devices. 2.信号调节器。信号调节器过滤随机的电噪声并将从转换器设备中产生的模拟信号平稳，流畅。

3.Multiplexers, which connect several process-monitoring devices to the analog-to-digital converter(ADC). Each process signal is sampled at periodic intervals and passed on to the converter.

3.多路调制器：多路调制器通过几个过程监控设备与模拟到数字变换器连接（ADC）。每个过程信号在周期间隔取样并通过转换器。

4.Amplifiers scale the incoming signal up or down to the range of the analog-to-digital converter being used. 4.放大器：放大器将输入的信号放大或者缩小到模拟数字变换器要使用的范围。

5.The analog-to-digital converter transforms the incoming real-valued process signals into their digital equivalents. 5.模拟数字变换器：模拟数字变换器将输入的真实值过程信号转换成相应的数值。

6.The digital computer's I/O section [/color]accepts the digital signals from the ADC, A limit comparator is often connected between the I/O sections and the ADC to prevent out-of-limit signals from distracting the CPU.

6.数字计算机I/O部分：数字计算机I/O部分从ADC中接收数字信号。I/O部分与ADC之间常常由一个限制比较器连接以防止因信号越界而分散CPU的精力。

The contact input interface is a set of simple contacts that can be opened and closed to indicate the status of limit switches, button positions, and other binary-type data. It serves as the intermediary between discrete process data and the computer, which periodically scans the signal status and compares it with preprogrammed values.

接触输入接口是一组简单的可开可关进而表示限制开关，按钮位置及其他二进制类型数据状态的触点组成。它作为中介服务于离散过程数据与计算机之间.负责周期性地扫描信号状态并将信号状态与预定程序的值进行比较。

Digital transducers belong to a class of electronic measuring instruments that generate as output a series of electrical pulses of uniform magnitude. A pulse counter is used to convert the pulse trains into a digital representation, which is then applied to the computer's input channel. The last three devices discussed are concerned with processing data from the computer to the prcess.

数字传感器属于一类产生输出一系列统一大小的电脉冲的电子测量仪器。脉冲计算器用于将脉冲链转换成数字表示。转换后的数值应用于计算机的输入通道。

The digital-to -analog converter takes digital data generated by the computer and transforms it into a pseudoanalog signal. The signal is considered pseudoanalog because the computer is only capable of processing a limited-precision digital word, so that an infinite number of analog signal levels cannot be generated.

数字模拟变换器获得电脑产生的数字数据并将数字数据转换成虚拟的模拟信号。模拟信号被称为是虚拟模拟信号是因为计算机只能处理有一定精度的数据。因而无穷多个模拟信号精度不能生成。

Contact output interfaces,like their input counterparts,are sets of contacts that can be opened or closed.The output word of the computer s used to turn on indicator lights,alarms, and even equipment fuctions such as cutting oil pumps.

接触输出接口，与 接触输入接口相似，也是由一组可开可关的触点组成。计算机输出指令用于开启指示灯，警报甚至设备功能如切削油水泵。

Pulse generators are frequently used as output devices which convert digital words from the computer into pulse trains that are used to drive devices such as stepping motors.

脉冲发生器通常用于将从计算机输出的数字指令转换为用于驱动设备如步进电机的脉冲链的输出设备。 Computer Network Structures 计算机网络结构

The term \in 1964, computer networks have developed through many technoloty phases such as Multi-computer System. Local Area work(LAN),

Metropolitan Area Network(MAN), Wide Area Network(WAN) and Network Computing. Now its appearance has become one of the most significant engineering achievements ever in human history. It can be used for many purposes such as intercommunication, digital online service and information share, Computer network can be used in almost every case. The utilization of computer network in mechanical engineering includes many scientific subjects such as Network Manufacturing, Virtual Manufacturing,Flexible Manufacturing System and Agile Manufacturing.

专有名词“计算机网络”指的是在不同地区计算机间的实际的物理连接。自从它一出现在1964年,计算机网络已经经过了许多的技术发展阶段如：多计算机系统，局域网(LAN)、大都会区域网络(MAN)、广域网络(WAN)和网络运算。现在计算机网络的出现已经成为人类史上重要的一项工程成就。它可用于许多场合如交流、数字在线服务和信息共享。计算机网络技术几乎可以被用在所有的情况.计算机网络在机械工程方面的应用包括许多科研课题如：网络制造、虚拟制造,柔性加工系统和敏捷制造。

Network Structures 网络结构

Computer network consists not only many computers, but also the terminals, transmission lines, switching centers and many other technology devices required to accomplish the desired function of the system.The number of possible configurations is limitless.However, the various network arrangments divide themselves into several basic categories, sometime called topologies. Five of the most common used topologies are illustrated in Fig.1.2. 计算机网络不仅仅是许多计算机组成，同时也包含有终端，输电线路,开关中心和许多其他要求完成系统需求功能的科技设备。可能配置的数目是无限的，但是通过将自己的各种网络分成几个基本范畴，有时称为拓扑结构。5种最常用的拓扑结构如图1。2所示。

In the point-to-point configuration, a communication line is established between two devices (typically,a computer and a peripheral devices such as a terminal). It is a relatively simple configuration if the number of devices is limited. However, when there are a large number of processors in the structure,the number of point-to-point communication links can become significantly complex and large, resulting in a relatively expensive system.Other network structures share the communication links in various way to avoid this expense. An inherent advantage of the point-to-point configuration is that whenever one of the direct links is broken, the other connection can remain intact.

在点对点配置，在两设备间建立起一条连接线（通常一台计算机和一个外部设备如:终端）如果设备的数量是有限制的这种是相对简单的配置。但是然而,当有大量的处理器的数量结构时点对点通讯联系会变得明显复杂和大型，导致相对昂贵的系统。其他网络结构分享通讯联系,以各种方式来避免这费用，一个固有的优点是,每当一个点对点配置的直接连接已被破坏,则其他连接可以保持完好。

The star network consists of a central computer and many other peripheral devices connected to it. The central computer is referred to as the master and the peripherals are called slaves. The function of the master is to delegate tasks to each of the smaller units or to act as a switch to connect varioius units. One of the important deficiencies of the star configuration is that the entire network system. is put out of operation if the central computer fails.

星型网络是由中心计算机及与之相连接的许多其他周边设置组成。中心计算机作为主人而周边设备为奴隶。中主人的功能是把工作委派给每个小单位或者作为一个开关连接各单位。星型配置最重要的缺点是如果中心计算机停止作用整个网络系统就会陷于瘫痪。

In the multidrop network structure, computers and other devices are connected by a single communication line. This line is either a bus or a serial channel.The limitatoin of this arrangement is that only two processors are allowed to transmit data to each other at the same time. This reults from the shared nature of the communication lines.

在多节点网络结构中，连接电脑和其他的装置由一个单一的通讯线路。这一线路可以是总线或者是串行通道。这一种排列的限制在于在同一时间只有两部处理器能进行数据传输。通信光缆的共享导致了这一结果。

In a loop configuration, each computer is connected to a communication line, which begins and terminates at a loop controller, typically a computer that maintains control over inter computer communication. Messages to a specific computer are usually transimitted to all computers in the network, with the address decoding its address and accepting the information.

在循环式配置中，每个计算机都连接在一条通讯线路上，在每个循环控制中每个计算机是开始端也是终止端。通常每台计算机都保持着内部计算机间的连接控制。送往某特定计算机的信息，一般都传送到网络中的所有计算机，同时由信息接收计算机译出地址码并接收信息。

In the tree configuration, a main computer is connected with many other devies, which at the subordinate position, and each of the subordinate devices is connected by its own subordinators. Thus this relationship is like a tree which is planted upside down. Message and instruction transmission between the main computer and its own subordinate devices is rather simple and fast in this configuration. But the deficiency of this configuration is that the direct relationship two counterparts isn't realized easily.

在树型配置中，一台主电脑与其他一些处于下级设备连接，每个下级设备都与自身的下级设备相连接。因此这样的从属关系就像一颗倒过来的树。在这种配置中信息与指令在主电脑与从属设备是相当简单并快速的。但这种配置的缺点在于两种相似

设备的直接关系并不能轻松的知道。

Network Protocols and OSI System Structure 网络协议和OSI系统

In a network all computers are connected and communicated with each other according to some kinds of enacted regulations or agreement, which are called the \ or acceptance of information. The most common protocl which is being used is Transport Control Protocol/ Internet Protocol(TCP/IP). Among many system models illustrating network protocols in the world, the ISO/OSI network model enacted by Internetional Standardization Organization has divided the whole system seven layers, each layer has its own name and function repspectively. The system model structure is illustrated in Fig.1.3:

在网络中，所有的计算机都根据一些规则和协议进行连接和通信，规则和协议称为网络协议。网络协议的主要功能是实现有序传输或接收信息。目前正在使用最常见的规范是传输控制协议/互联网协议(TCP / IP)。在世界上许多系统模型阐明了网络协议，由国际标准化组织制定的ISO/OSI网络模型将整个系统分为7个层次。每个层次都有自身的名字与功能，系统模型结构如1.3图所示：

Physical layer.Ensuring correct data transmission between different devices by the utilization of physical media. 物理层：利用物理媒质确保在不同的装置之间的正确的数据传输。

Data link layer.Transfering the physical link into reliable data link by the use of many methods such as revision, confirmation and feedback.

数据连接层：通过利用一些方法如：修改，确定，反馈将物理连接转换成实际的数据连接。

Network layer. Solving the problems about how to send the data from origin place to termination by the method of grouping. 网络层：通过分组的方法解决怎么样从原始位置传输数据到终端的问题。

Transport layer. Offering the transparent service of point-to-point data transportation. 传输层；提供点对点隐形的数据传输服务。

Session layer. Organizing and synchronizing the process intercommunication between different main computers. 会话层：组织和同步不同主机间的交流过程。

Presentation layer.Offering the presentation of data or information for higher layer customers. 提案层：为更高层次的客户提供数据或信息提案。

Application layer.Offering the method for specific type of network application to visit the OSI environment. 应用层：为特定类型的网络应用提供方法访问OSI环境。 Internet Application and Development 互联网应用和发展

The widest area network in the world is Internet. It is one kind of Wide Area Virtual Networks, which uses TCP/IP protocol and interconnects more than tens of million computers around the world into a gigantic network system. Each computer of internet has its sole address in the world, thus its application can overcome the limitation of continents, countries and areas, and make up a virtual space in which every person can receive the lastest news and enjoy the fastest service even when he is in the most remote area of the world.Today, more and more computers and devices are connected with internet system, more and more service and information can be offered by the utilization of internet, and it has become an important base for Information Super Highway Structure Plan in many countries. One of the fastest growing areas of internet is the application of World Wide Web, in which all kinds of information such as text, graphics, sound and many other multimedia files can be viewed together and navigated via hypertext links. With the rapid development of information and electronics technology,internet is developing by an incredibly speed and it has become an indispensable component of human's civilization.

在世界上应用得最广泛的区域网络是互联网。它是一种广泛的虚拟网络，利用TCP/IP协议将全球数以百万计的计算机内部连接成一个庞大的网络系统。在世界范围内每台计算机网络都有它唯一的地址，因此互联网可以克服大洲，城市和区域的限制，并组成一个每个人都可以获得最新新闻和享受最快的服务的虚拟空间即使他是在世界上最偏远的地区.至今，越来越多的电脑和设备连接到了互联网上，越来越多的服务及信息利用互联网可以得到提供，在很多国家，信息高速公路结构计划已成为一项重要的基础研究。互联网发展最快的领域之一是万维网的应用，在互联网中，各种信息，如文本，图像，声音和许多其他多媒体文件，可以通过超文本外国投资功能共同观看和导航。随着信息与电子技术的快速发展，互联网以一个令人难以置信的速度发展,并已经成为人类文明程序不可缺少的重要组成部分。

Part02 Unit02 Numerical Control Of Production Equipment

Numerical control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particular workpart or job. When the job changes, the program of instructions is changed. The capability to change the program is what makes NC suitable for low-and medium-volume production. It is much easier to write new programs than to make major

alterations of the processing equipment.

数控是程序控制的自动化，在数字控制系统中，设备通过数字，字母和符号来编码，以一种合适的格式为每一个特定的零件或工件定义一个程序指令集。当工件变化时，程序也变化，改变程序的能力也就是适合中小批量生产。写一个新程序比改变大量生产设备要容易的多。

BASIC COMPONENTS OF NC 数控的基本结构

A numerical control system consists of the following three basic components: 数控系统由下面三部分组成：

?Program of instructions 控制程序； ?Machine control unit 机器控制单元 ?Processing equipment 加工设备

The general relationship among the three components is illustrated in Fig.2.1. The program is fed into the control unit, which directs the processing equipment accordingly.

三部分的基本关系，由图2.1所示。程序输入到控制单元由送入的程序来引导加工设备控制。

The program of instructions is the detailed step-by-step commands that direct the processing equipment. In its most common form, the commands refer to positions of a machine tool spindle with respect to the worktable on which the part is fixtured. More advanced instructions include selection of spindle speeds, cutting tool, and other function. The most common medium in use over the last several decades has been 1-in. -wide punched tape. Because of the widespread use of the punched tape, NC is sometimes called “tape control”. However, this is a misnomer in modern usage of numerical control. Coming into use more recently have been magnetic tape cassettes and floppy diskettes.

指导程序是一步步详细的指导加工设备的指令。通常指令把主轴上刀具相对于安装工具的工作台定位。更多先进的说明包括主轴的转速，加工工具的选择及其功能。程序刻在合适的介质中，提交到机器控制单元中，在过去几十年中，最常用的介质是一英寸宽的打孔纸带。由于打孔纸带的广泛使用，NC有时也叫纸带控制，然而这是现代数控使用的误称。现在进入使用更多的是磁带和软盘。

The machine control unit (MCU) consists of the electronics and control hardware that read and interpret the program of instruction and convert it into mechanical actions of the machine tool or other processing equipment.

机器控制单元（MUC）由电子和控制硬件组成，机器控制单元可以读出和执行指令程序，可以自动改变加工工具和其他加工设备。

The processing equipment is the third basic component of an NC system. It is the component that performs useful work. In the most common example of numerical control, one that performs machining operations, the processing equipment consists of the worktable and spindle as well as the motors and controls needed to drive them.

执行单元是数控系统的第三基础部分，执行原件是有效执行工作的原件，最常见的数控例子其中的一个加工操作，加工设备由工作台和主轴组成，就像用电动机来驱动一样。加工设备由控制单元来驱动控制系统的类型。 TYPES OF CONTROL SYSTEMS 控制系统的类型

There are two basic types of control systems in numerical control: point-to-point and contouring. In the point-to-point system, also called positioning, each axis of the machine is driven separately by leadscrews and, depending on the type of operation, at different velocities. The machine moves initially at maximum velocity in order to reduce nonproductive time but decelerates as the tool reaches its numerically defined position. Thus in an potation such as drilling or punching, the positioning and cutting take place sequentially. After the hole is drilled or punched, the tool retracts, moves rapidly to another position, and repeats the operation. The path followed from one position to another is important in only one respect: The time required should be minimized for efficiency. Point-to-point systems are used mainly in drilling, punching, and straight milling operations.

数控有2种基本类型，点对点式和轮廓式控制，点对点式控制也称定位控制，每个轴都是通过丝杠单独驱动，根据加工类型不同，加工速度也不一样。机器开始以最大速度运行来减少非加工时间，但当他达到数据定义的位置时，机器开始减速。因此在一个操作中，如钻或冲孔操作先定位在加工。在钻或冲孔之后，迅速收起工具移动到另一个位置重复此操作。从一个位置移到另一个位置是非常重要的，要遵循一个原则，从效率上考虑只要时间最短即可。点对点系统主要用于钻、冲孔、直铣操作中。

In the contouring system, also known as the continuous path system, positioning and cutting operations are both along controlled paths but at different velocities. Because the tool cuts as it travels along a prescribed path, accurate control and synchronization of velocities and movements are important. The contouring system is used on lathes, milling machines, grinders, welding machinery, and machining centers.

轮廓式也就是连续路径式系统，定位和切削同时按不同速度来控制，由于刀具在指定路线运动同时切削，因此速度和运动的同步控制是非常重要的。轮廓式系统常用于车床铣床磨床焊接设备和加工中心。

Movement along the path, or interpolation, occurs incrementally, by one of several basic methods. In all interpolations, the path

controlled is that of the center of rotation of the tool. Compensation for different tools, different diameter tools, or tool wear during machining, can be made in the NC program.There are a number of interpolation schemes that have been developed to deal with the various problems that are encountered in generating a smooth continuous path with a contouring-type NC system. They include:

沿着路径的运动或以增量差补是几个基本方式的一个，在所有的差补中，要控制刀具的回转中心定位，补偿可以以不同直径及刀具磨损，在数控程序中进行改写。有一些已形成差补方案来处理数控系统中连续路径和加工系统产生的问题包括： ◆Linear interpolation 线性差补； ◆Circular interpolation 圆弧差补 ◆Helical interpolation 螺旋线差补 ◆Parabolic interpolation 抛物线差补 ◆Cubic interpolation 立体差补

Each of these interpolation procedures permits the programmer (or operator) to generate machine instructions for linear or curvilinear paths, using a relatively few input parameters. The interpolation module in the MCU performs the calculations and directs the tool along the path.

每一种差补程序都允许程序源产生加工指令，适用于相对少的输入参数的直线或曲线路径。储存在数控单元中的模块预算指引工具沿计算出的路径运动。

Linear interpolation is the most basic and is used when a straight-line path is to be generated in continuous-path NC. Two-axis and three-axis linear interpolation routines are sometimes distinguished in practice, but conceptually they are the same. The program is required to specify the beginning point and end point of the straight line, and the feed rate that is to be followed along the straight line. The interpolator computes the feed rates for each of the two (or three) axes in order to achieve the specified feed rate.

线性差补是最基本的差补方法，用于连续路径的数控系统中。两轴和三轴线性差补路线在实际中有时会分辨出的，但在概念上他们是一样的，程序源要明确指定直线的起点和缺点及沿直线的进给率。差补需计算两轴或三轴的进给速率以达到设定的进给速度。

Linear interpolation for creating a circular path would be quite inappropriate because the programmer would be required to specify the line segments and their respective end points that are to be used to approximate the circle. Circular interpolation schemes have been developed that permit the programming of a path consisting of a circular arc by specifying the following parameters of the arc: the coordinates of its end points, the coordinates of its center, its radius, and the direction of the cutter along the arc. The tool path that is created consists of a series of straight-line segments, but the segments are calculated by the interpolation module rather than the programmer. The cutter is directed to move along each line segment one by one in order to generate the smooth circular path. A limitation of circular interpolation is that the plane in which the circular arc exists must be a plane defined by two axes of the NC system.

线性差补用来差补圆是不合适的因为程序源需要明确指定线段部分（线段数量）和各自的终点来大约模拟圆弧。圆弧差补法已形成他允许程序编程的路径，使用圆弧只要给定以下参数，圆弧终点坐标，圆心坐标，半径和刀具沿圆弧路径的走刀方向。圆弧差补也是由许多小的直线段来实现的，但这些小线段的参数由差补模块来计算出来的，而不是程序员设定的。切削是沿着每一小线段一个一个的进行以产生光滑曲线路径。圆弧差补的局限性是圆弧路径所在平面是由数控系统中两轴所决定的平面。

Helical interpolation combines the circular interpolation scheme for two axes described above with linear movement of a third axis. This permits the definition of a helical path in three-dimensional space.

螺旋线差补结合了环形差补两轴在第三轴上做线性运动这样来定义空间三维螺旋路径。

Parabolic and cubic interpolation routines are used to provide approximations of free-form curves using higher-order equations. They generally require considerable computational power and are not as common as linear and circular interpolation. Their applications are concentrated in the automobile industry for fabricating dies for car body panels styled with free-form designs that cannot accurately and conveniently be approximated by combining linear and circular interpolations.

抛物线差补和立方差补法通过高次高程来实现自由曲线。这通常需要有强的计算能力，正因如此，他不如直线差补和环形差补常见。他们主要用于汽车工业中具有自由风格的车身面，而这是线性差补和圆弧差补不能精确容易得到的。

The most common application of numerical control is for machine tool control.This was the first application of NC and is today the most important commercially. In this section we discuss the machine tool application of NC with emphasis on metal machining.

数控技术运用于数控机床，这是数控的主要应用。现在主要用于商业。我们仍讨论数控系统特别是金属数控车床。 Machine Tool Technoloty for NC 数控车床技术

Each of the five machining processes is carried out on a machine tool designed to perform that process. Turing is performed on a lathe, drilling is done on a drill press, milling on a milling machining , and so on . There are several different types of grinding operations with a corresponding variety of machines to perform them. Numerical control machine tools have been designed for nearly all of the

machining processes. The list include:

5种加工过程都可以在设计的专门车床上来实现加工。在车床上车削，在钻床上钻，在铣床上加工。有几种类型的磨削方法也要有相应种类的磨床。被设计的数控磨床可以进行下列加工包括： ●Drill presses 钻加工

●Milling machines, vertical spindle and horizontal spindle 铣床立式和卧式主轴 ●Turing machines, both horizontal axis and vertical axis 车床卧式主轴和立式主轴 ●Horizontal and vertical boring mills 卧式和立式镗床 ●Profiling and contouring mills 仿形铣床

●Surface grinders and cylindrical grinders 平面磨和圆柱磨

In addition to the machining process, NC machine tools have also been developed for other metalworking processes. These machines include:

除了上述几种机械加工方法，数控机床可用于其他金属加工过程包括：

●Punch presses for sheet metal hole punching 用于薄片板的金属板上冲孔的冲压机 ●Presses for sheet metal bending 用于薄片金属弯曲的折弯机

The introduction of numerical control has had a pronounced influence on the design and operation of machine tools. One of the effects of NC has been that the proportion of time spent by the machine cutting metal under program control is significantly greater than with manually operated machines.This causes certain components, such as the spindle, drive gears, and feed screws, to wear more rapidly, These components must be designed to last longer on. NC machines .Second, the addition of the electronic control unit has increased the cost of the machine, therefore requiring higher equipment utilization. Instead of running the machine on only one shift, which was the convention with manually operated machines, NC machines are designed to reduce the time consumed by the nonprocessing elements in the operation cycle,such as loading and unloading the workpart, and changing tools. Consider the role of the human operator. Instead of being the highly skilled worker who controled every aspect of the part prodution, the tasks of the operator have been reduced to part loading and unloading, tool changing, chip clearing, and the like. In this way, one operator can often run two or three automatic machines. The role and functions of the machine tool have also changed. NC machines are designed to be highly automatic and capable of combining several operations in one setup that formerly required several different machines. These changes are best exemplified by a new type of machine that did not exist prior to the advent and development of numerical control: the machining center.

数控技术的介入到机加工对机床的设计和运用有着显著的影响。数控影响之一在程序控制下切削金属的时间与传统手动机床大得多。所以对于一些零件如主轴驱动主轴丝杠磨损更快，这些零件要设计成持续时间长的。第二，增加电子控制单元后设备成本也随之增加，因此需要更高的利用率。取代传统手工操作的一班制，数控机床通常采用两班或三班制来获得更多的回报。数控机床的设计中减少了非操作过程的时间如装卸工件和换刀时间。第三，增加的劳动成本由人工成本变为设备成本。考虑到人工操作的角色，角色由技术熟练的工人控制，工件生产的每一个过程变为只控制装卸换刀和清除碎屑和类似的操作，这样一个工人可以同时操作两台或三台车床，机床的角色和功能也改变了。数控需要设计成高度自动化具有需要在不同车床加工几种操作联合在一起一定加工的能力，这些变化是通过一种新型车床在数控技术存在之前是不存在的，他丰富了数控加工中心。

The machining certer, developed in the late 1950s, is a machine tool capable of performing several different machining operations on a workpart in one setup under program control. The machining certer is capable of milling,drilling reaming,tapping,boring, facing, and similar operations.In addition, the features that typicallycharacterize the NC machining center include the following:

加工中心是在20世纪50年代发展起来的具有在程序控制下在一个工件上一次裝夹完成几种不同的加工能力的机床。加工中心能完成铣，钻，铰屑，攻丝，镗，车端面及一些类似机加工工作。另外数控加工中心的典型特征包括以下方面：

(1)Automatic tool-changing capability.A variety of machining operations means that a variety of tools is required. The tools are contained on the machine in a tool magazine or drum. When a tool needs to be changed. the tool drum rotates to the proper position, and an automatic tool changing mechanism, operating under program control, exchanges the tool in the spindle and the tool in the drum.

(1)自动换刀能力: 多种机加工工作一位着需要多种刀具。刀具贝安装在刀库或多刀刀库中。当一把刀需要被调换时，多刀刀座自动旋转到相应的位置上。自动化的换刀机构。在程序控制下进行，把主轴上需换下的刀和多刀刀座上的刀调换。

(2)Automatic workpart positioning.Most machining certers have the capability to rotate the job relative to the spindle, thereby permitting the cutting tool to access four surfaces of the part.

(2)工件的自动定位: 大多数加工中心都可以使工件沿着主轴旋转因此允许刀具达到工件的四个表面。

(3)Pallet shuttle.Another feature is that the machining center has two( or more) separate pallets that can be presented to the cutting tool.While machining is being performed with one pallet in position in fromt of the tool, the other pallet is in a safe locaition away from the spindle. In this way, the operator can unload the finished part from the prior cycle and fixture the raw workpart for the next

cycle while machining is being performed on the current workpiece.

(3)托架滑动装置（平板架）: 加工中心另一个特点是有两个或多个独立拖板每个拖板都可以调整在刀具上。在加工过程中，一个拖板在刀具的前部，另一个拖板在远离主轴的安全位置。这样当机床正在加工当前的零件时。操作人员就可以从上一个工作循环中卸下最终加工好的零件，同时加紧毛坯用于下一个工作循环。

Machining centers are classified as vertical or horizontal.The descriptor refers to the orientation of the machine tool spindle. A vertical machining cernter has its spindle on a vertical axis relative to the worktable,and a horizontal machining center has its spindle on a horizontal axis. This distinction generally results in a difference in the type of works that is performed on the machine. A vertical machining center is used for cube-shaped parts where tool access can best be achieved on the sides of the cube.An example of an NC horizontal machining center, capable of many of the features described above, is shown in Fig.2.2.

加工中心可以分为立式和卧式。这是参照机床主轴方向来划分的。立式加工中心具有轴线相对工作台垂直的主轴，卧式车床的主轴轴线是水平方向的。这种区别通常会导致在这些加工中心加工的零件类型不同。立式加工中心用于以上进刀的平面工作。卧式加工中心用于立体形状，刀具在立体侧面可以进刀。一台数控卧式加工中心，例子如图2.2所示，具有上面提到的一些特征。

The success of the machining center has resulted in the development of similar machine tools for other metalworking processes. One example is the turning center, designed as a highly automated and versatile machine tool for performing turning, facing, drilling, threading, and related operations.

加工中心的成功应用导致了其他类似金属加工机床的发展。例如：在车削中心，把车削加工设计成一个高度自动化万能机床可以完成车削，刨，钻，螺纹加工和类似的操作。 DNC and CNC 直接数据控制和计算机数字控制

The development of numerical control was a significant achievement in batch and job shop manufacturing, from both a technological and a commercal viewpoint. There have been two enhancements and extensions of NC technoloty , including: 数控的发展在分批生产和小批量生产中有着重要意义，从技术和商业角度来说都有着重要意义。数控有两方面的提高和扩展，包括：

●Direct numerical control 直接数据控制

●Computer numerical control 计算机数字控制 (1)Direct numercal control 直接数据控制

Direct numercal control can be defined as a manufacturing system in which a number of machines are controled by a computer through direct connection and in real time.The tape reader is omitted in DNC, thus relieving the system of its least reliable component. Instead of using the tape reader, the program is transimitted to the machine tool directly from the computer memory.In principle, one computer can be used to control more than 100 separate machines.(One commercial DNC system during the 1970s boasted a control capability of up to 256 machine tools.) The DNC computer is designed to provide instructions to each machine tool on demand. When the machine needs control commands,they are communicated to it immediately.

直接数据控制定义为一个制造系统，一定数量的机床有一台计算机通过直接硬件连线实时控制。相应的磁带播放机忽略在直接数控中，这样就消除系统中最不可靠的环节。不用磁带播放机而用电脑信息传给车床。原则上说一台计算机可以控制100台独立机器（DNC系统在1970年称为可控制26台机床）直接数控（DNC）电脑设计成在需要的时候提供指令给每一台机床，当机床需要控制指令时，计算机立即发送指令给机床。

Fig.2.3 illustrates the general DNC configuration. The system consists of four components： 图2.3说明了DNC的基本配置。这个系统包括4部分： ?Central computer 中央计算机

?Bulk memory, which stores the NC part programs 大量内存，用于存放数控程序 ?Telecommunication lines 通信线 ?Machine tools 机床刀具

The computer calls the part program instructions from bulk storage and sends them to the individual machines as the need arises. It also receives data back from the machines. This two-way information flow occurs in real time, which means that each machine's requests for instructions must be satisfied almost instaneously, Similarly, the computer must always be ready to receive information from the machines and to respond accordingly. The remarkable feature of the DNC system is that the computer is serving a large number of separate machine tools all in real time. Depending on the numbef of machines and the computational requirements that are imposed on the computer, it is sometimes mecessary to make use of satellite computers, as shown in Fig.2.4. These satellites are smaller computers, and they serve to take some of the burden off the larger central computer.Each satellite controls several machines. Groups of part program instructions are received from the central computer and stored in buffers. They are then dispensed to the individual machines as required. Feedback data from machines are also stored in the satellite's buffer before being collected at the central computer.

计算机从海量内存中取出部分程序指令送入到需要的独立机床中。相应的计算机也接受机床反馈信息。这种双工的信息流在实时控制加工系统中出现意味着每台机床需要指令的请求能立即得到回应。类似的，计算机必须总是要准备要接受信息和进行回应。DNC系统显著特点是：可以实时控制大量机床。更具机器数量和所需的计算机程度化。有时需要使用卫星计算机如图2.4所示。卫星计算机是更小的计算机，可以分担中央计算任务，减轻其负担。每台卫星控制几台机床。零件加工指令程序由计算机接受，储存在内存中。当需要时卫星计算机发送指令程序到每个独立机床中。来自机床的反馈数据在电脑中央存储接受之前存储在卫星内存中。

(2)Computer numercial control 计算机数字控制

Since the introduction of DNC, there have been dramatic advances in computer technoloty. The physical size and xost of a digital computer have been significantly reduced at the same time that its computational capabilities have been substantially increased. In numercial control, the result of these advances has been that the large hard-wired MCUs of conventional NC have been replaced by control units based on the digital computer. Initially,minicomputers were utilized in the early 1970s,As further miniaturization occurred in computers, minicomputers were replaced by today's microcomputers.

由于DNC技术的介入，在计算机技术上得到了很大的发展。计算机在尺寸和成本显著减少的同时，计算机的能力却有很大的提高。在数控中，这些发展使得由硬件布置的MCU（）变为数字电脑控制的控制单元。最早，小型机在1970年使用。随着计算机进一步小型化，小型机被当今的微型机取代。

Computer numercial control is an NC system using dedicated microcomputer as the machine control unit. Because a digital computer is used in both CNC and DNC, it is appropriate to distinguish between the two types of system. There are three principal differences: 计算机控制也是一种数字控制，它采用微型计算机作为控制单元。由于数字电脑用于CNC 和DNC中，只近似区分两种类型。有三个区分原则：

◎DNC computers distribute instructional data to , and collect data from, a large number of machines. CNC computers control only one machine, or a small number of machine.

◎DNC电脑接受和发送指令数据都是来自许多机器，CNC电脑控制只是一个机器或多个机器。

◎DNC computers occupy a location that is typically remote from the machines under their control. CNC computers are located very near their machine tool.

◎DNC电脑占有一个位置通过控制来实现机器的旋转。CNC电脑要非常靠近车床。

◎DNC software is developed not only to control individual pieces of production equipment, but also to serve as part of a management information system in the manufacturing sector of the firm. CNC software is developed to augment the capabilities of a particular machine tool.

◎DNC软件的发展不经可以控制生产设备的每个单独零件，还可以在生产坚固性方面提供主要控制信息。CNC的提高可以提高特殊车床的能力。

The general configuration of a computer numerical control system is pictured in Fig.2.5.As illustrated in the diagram, the controller has a tape reader for initial entry of a part program.In this regard.the outward appearance of a CNC system is similar to that of a conventional NC machine. However, the way in which the program is used in CNC to different. With a conventional NC system, the punched tape is cycled through the tape reader for each workpart in the batch. The MCU reads in a block of instructions on the tape, executing that block before proceeding to the next block. In CNC,the entire program is entered once and stored in computer memory,The machining cycle for each part is controlled by the program contained in memory rather than from the tape itself.

电脑数控系统的大体配置如图2.5所示。如图中所示，最初进入控制器的是磁带播放机。这样，CNC的外部系统与传统的NC机相似。然而CNC中的程序使用方法是不同的 。对于传统CNC系统，在批量生产每个工件时，打孔磁带周期性地通过读卡器，单片机读取磁带一块指令代码，在继续读取下一段指令代码时先执行上一段代码。在CNC系统中，全部程序代码一次性输入并储存在电脑寄存器里。每个工件的加工周期由寄存器里的程序而不是磁带自身控制。

Control algorithms contained in the computer convert the part program instructions into actions of the machine tool(or other processing equipment). Certain functions are carried out by hard-wired components in the MCU. For example, circular interpolation calculations are often performed by hard-wired circuits rather than by stored program.Also, a hardware interface is required to make the connections with the machine tool servosystems.

计算机内的控制运算将零件程序指令转换为加工刀具的运动（或者其他处理设备）。寄存器内部的布线组件实现指定的功能。如：圆形插补计算常常是由布线电路执行而不是存储的程序。此外，一件硬件接口需要与加工刀具伺服系统相连接。 (3)Features of CNC control 数控机械床的控制特点

In previous the important features and functions of the machine control unit in numerical control were described. CNC has made possible additional features beyond what is normally found in a conventional hard-wired MCU. Some of these features include the following:

上述对数控机床控制单元的重要特征及功能进行了描述。CNC新增的特征可能超过了传统布线式单片机已有的特征。其中的一些特点包括以下：

1)Storage of more than one part program.[/color] With improvements in computer technology, many of the newer CNC controllers have a large enough capacity to store more than a single program This translates into the capability to store either one every large program or several small and mediumsized programs.

1)存储一种以上的零件程序：随着计算机技术的进步，许多新数控控制器有一个足够大的容量来储存一条以上的程序。这转化为能够存储其中的每一个大程序或几个中小项目。

2)Use of diskettes.[/color] There is a growing use of floppy disks for part programs in manufacturing. The capacity of an 8-in,diskette is the approximate equivalent of 8000 ft of punched tape. Because of this more modern storage technoloty, many CNC controllers have the optional capability to read in programs stored on disks as well as punched tape.

2)磁盘的运用：在制造业用于存放零件程序的软盘日益得到使用。8英尺的容量磁盘大概相当于8000英尺复卷录音带，由于这种更现代的存储技术，许多数控控制器具有可选功能选取储存在磁盘以及穿孔胶带的程序。

3)Program editing at the machine tool site.[/color] To deal with the mistakes in part programming, CNC system permit the program to be edited while it is in computer memory. Hence, the process of testing and correcting the program can be done entirely at the machine site rather than returning to the programming office in the shop to make the tape corrections. In addition to part program corrections, editing can also be done to optimize the cutting conditions of the machining cycle. After correcting and optimizing the program, a tape punch can be connected to the CNC controller in order to obtain a revised version of the tape for future use.

3)在机床工具地址程序程序：为了处理零件程序中的错误，CNC系统允许对存储于计算机内在中的程序进行编辑，因此，程序的测试和纠正过程完全可在机器地址中完成,而不用返回到程序公司去更正磁带。除了零件程序的更正，编辑亦可优化切割条件的加工周期，程序更正及优化后，打孔磁带可以与数控控制器进行连接以获得修改版本的磁带，以备将来使用。

4)Fixed cycles and programming subroutines.The increased memory capacity and the ability program the control computer in CNC provides the opportunity to store frequently used machining cycles in memory that can be called by the part program.Instead of writing the instructions for the particular cycle into every program, a code is written into the program to indicate that the cycle should be executed. Some of these cycles require the definition of certain parameters in order to execute, An example is a bolt hole circle, in which the diameter of the bolt circle, the spacing of the bolt holes,and other parameters must be specified, In other cases, the particular machining cycle used by the shop would not require parameter definition. 4)固定循环及编程子程序：在CNC中控制计算机增加的内存容量和程序的能力为存储常用的加工循环程序提供了机会，加工循环程序可以为零件程序所调用，而不用将有特定周期的指令写入每个程序中。程序中写入一个代码指示循环需要被执行。为了能够执行这些循环需要定义的一定的参数。比如螺栓孔圈，螺栓孔圈的直径，间距及其他变量需要确定。在其他情况下，商店中使用的特定加工循环不需要定义变量。

5)Interpolation.Some of the interpolation schemes are normally executed only on a CNC system because of the computational requirements. Linear and circular interpolation are often hare-wired into the control unit. Helical , parabolic, and cubic interpolations are usually executed in a stored program algorithm. | v:C,? N?G

5)插补：因为的计算需要，一些插值方案通常只有在数控系统执行，直线插补和圆弧插补通常以布线计算的形式进入控制单元，而螺旋,抛物线和立方插补通常由存储的程序算法执行。

6)Positioning features for setup.Setting up the machine tool for a certain job involves installing and aligning the fixture on the machine tool table. This must be accomplished so that the machine axes are aligned with the workpart. The alignment task can be facilitated using certain feature that are made possible by software options in a CNC system. Position set is one of these features. With position set, the operator is not required to position the fixture on the machine table with extreme accuracy. Instead, the machine tool axes are referenced to the location of the fixture by using a target point or set of target points on the work or fixture.

6)安装定位功能：设置确定工作的加工工具包括在机床加工台上安装与对齐夹具。这一操作必须完成以让机床轴与工作对齐。在CNC系统中对齐工作可以很轻易的由特定的具有可选项的软件特征完成。定位设置就是其中一个特征，有了定位设置，操作员不需要在机床工作台上定位夹具定位得十分精度，相反地，机床轴通过在工件或者夹具上使用一个目标点或一套目标点参考夹具的位置进行定位。

7)Cutter length compensation.This is similar to the preceding feature but applies to tool length and diameter. In older-style controls, the cutter dimensions had to be set very precisely in order to agree with the tool path defined in the part program. Other methods for ensuring accurate tool path definition have been incorporated into newer CNC controls .One method involves manually entering the actual tool dimensions into the MCU. These actual dimesions may differ from those originally programmed. Compensations are then automatically made in the computed tool path. Another more recent innovation is to use a tool length sensor built into the machine. In this method, the cutter is mounted in the spindle and brought into contact with the sensor to measure its length. This measured value is then used to correct the programmed tool path.

7)刀具长度补偿：前述的情形特征与此相似但适用于工具长度和直径。在旧式控制中，为了与在零件程序中定义的刀具路径相一致切削刀具的尺寸必须安装得非常的精确。为了确保准确的刀具路径定义一些其他的方法被纳入了新式的CNC控制中，其中一种方法就是人工输入准备的刀具尺寸到内存中，这些准确的尺寸可能与原始的程序数据不同。然后插补器自动计算刀

具路径。另一种最新的革新就是在机床上装入一个刀具长度传感器，用这种方法，刀具安装在主轴上并接触到传感器以测定其长度，测定结果用于修正程序的刀具路径。

8)Diagnostics.Many modern CNC machines possess an on-line diagnstics capability which monitors certain aspects of the machine tool and MCU operation to detect malfunctions or signs of impending malfunctions. When a malfunction is detected, or measurements indicate that a breakdown is about to occur, a message is displayed on the controller's CRT monitor. Depending on the seriousness of the malfunction, the system can be stopped or maintenance can be scheduled for a nonproduction shift. Another use of the diagnostics capability is to help the repair crew determine the reason for a break down of the machine tool.One of the biggest problems when a machine failure occurs is often in diagnosing the reason for the breakdown. By monitoring and analyzing its own operation, the system can determine and communicate the reason for the failure.

8)诊断：许多现代数控机床具有在线监控系统，监控机床刀具及内存操作以便察觉发生或者即将发生的故障。当一个故障被检测到,或实测结果表明一个故障即将发生,在控制器的CRT显示器就会显示一条相关的错误信息。根据出现故障情节的轻重，系统可以停止或者保持在一个不进行生产的档位。另一个使用诊断能力是帮助维修工作确定中止机床的原因。当一个机床故障出现时其中最大的问题在于诊断故障的原因。通过监控及分析自身操作，该系统可以确定和对故障原因进行沟通。

9)Communications interface.[/color][/b] With the trend toward interfacing and networking in plants today, most modern CNC controllers are equipped with a standard communication interface to allow the particular tool to be linked to other computer and computer-driven devices.

9)通讯接口：随着当今工厂向着接口与网络技术的发展，大多数现代数控控制器配置一个标准的通信接口允许特定的工具与其它计算机和可供设备进行连接。

Part02 Unit03 Programming for Numerical Control

A program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process. Programming for NC may be done by an internal programming department, on the shop floor, or purchased from an outside source. Also, programming may be done manually or with computer assistance.

数控编程由一系列方向构成，这些方向导致数控车床执行某种操作，加工是最常用的进程。数控车床编程由内部编程部门来完成，在车间里，或者从外部源购买。编程还可以手动或者在计算机辅助下来完成。

The program contains instructions and commands. Geometric instructions pertain to relative movements between the tool and the workpiece. Processing instructions pertain to spindle speeds, feeds, tools, and so on. Travel instructions pertain to the type of interpolation and slow or rapid movements of the tool or worktable. Switching commands pertain to on/off position for coolant supplies, spindle rotation, direction of spindle rotation, tool changes, workpiece feeding, clamping, and so on.

程序包括指令和命令。几何指令涉及刀具和工件间的相对移动。进程指令涉及主轴速度，进给以及道具等。行动指令涉及插值的类型以及刀具或者工作台的缓慢和快速移动。切换命令涉及到开/关冷却液供给状况，主轴旋转，主轴方向，换刀，工件进给，夹具固定等等。

(1) Manual Programming.Manual part programming consists of first calculating dimensional relationships of the tool, workpiece, and work table, based on the engineering drawings of the part, and manufacturing operations to be performed and their sequence. A program sheet is then prepared, which consists of the necessary information to carry out the operation, such as cutting tools, spindle speeds, feeds, depth of cut, cutting fluids, power, and tool or workpiece ally a paper tape is first prepared for trying out and debugging the program. Depending on how often it is to be used, the tape may be made of more durable Mylar.

⑴手工编程。手工编程包括根据部分工程图纸首先算出刀具，工件以及工作台的尺寸关系，继而决定执行的操作和工序。那么一个包括执行特定操作所需必要信息的程序表就准备好了，例如刀具切削，主轴转速，进给，切削深度，切削液，以及刀具或者工件间的相对位置或者移动。根据这些信息，部分程序就准备好了。通常一个纸带首先被准备好用于试用和调试程序。根据纸带被使用多久，纸袋通常用更耐用的聚酯薄膜制成。

Manual programming can be done by someone knowledgeable about the particular process and able to understand, read, and change part programs. Because they are familiar with machine tools and process capabilities, skilled machinists can do manual programming with some training in programming. However, the work is tedious, time consuming, and uneconomical-and is used mostly in simple point-to-point applications.

手工编程可以由那些具有特定制造工艺知识和能够理解，阅读以及更改部分程序的人来完成。因为他们熟悉机床刀具和工艺流程，熟练的机械师可以做一些手工编程的编程培训。然而，所涉及的工作是乏味的，费时的，因此不合算。手工编程大多数用于简单的点对点应用上。(2) Computer-Aided Programm[b][color=Red][/color][/b]ing Computer-aided part programming involves special symbolic programming languages that determine the coordinate points of corners, edges, and surfaces of the part. Programming language is the means of communicating with the computer and involves the use of symbolic characters. The programmer describes the component to be processed in this language, and the computer converts it to commands for the NC machine.

Several languages having various features and applications are commercially available. The first language that used English-like statements was developed in the late 1950s and is called APT (for Automatically Programmed Tools). This language, in its various expanded forms, is still the most widely used for both point-to-point and continuous-path programming.

⑵计算机辅助编程。计算机辅助编程是一种涉及到特殊符号的编程语言，这种语言可以决定角点的坐标，刀口以及工件的表面。编程语言是与计算机通信的方式并且涉及到符号字符。编程员用这种语言描述加工零件，而由计算机将零件程序转换为数控机床的执行指令。许多种商业应用上的语言有多种多样的特点和应用。第一种被使用的是类似于英语语句的语言，它在十九世纪五十年代末被开发出来并被称为APT语言。这种语言，由于它多种多样的扩展形式，一直是最广泛的用于点对点和连续路径编程的语言。

Complex parts are now machined using graphics-based, computer-aided machining programs.A tool path is created in a largely graphic environment that is similar to a CAD program. The machine code(G-Code) is created automatically by the program.

复杂的工件现在使用基本的绘图进行制造，计算机辅助制造程序。刀具的路径是在类似于一个CAD程序的大量的绘图环境下制造出来的。这种机器代码由程序自动生成。

Before production begins, the programs should be verified.either by viewing a simulation of the process on a monitor or by making the part from an inexpensive material(such as aluminum, wood, wax,or plastic), rather than from the actual material specified for finished part.

在生产开始之前，程序应该被校验，还有就是通过一个显示器观看工艺流程的模仿或者使用廉价的材料（例如铝，木头，石蜡，或者是塑料）制作工件，而不是使用指定用于已加工零件的真实材料。

Computer-aided part programming has the following significant advantages over manual methods: ● Use of relatively easy to use symbolic language P8v S4c5H5L.? Y;F

●Reduced programming time. Programming is capable of accommodating a large amount of data concerning machine characteristics and process variables, such as power, speeds, feed, tool shape, compensation for tool shape changes, tool wear, deflections, and coolant use.

● Reduced possibility of human error, which can occur in manual programming

●Capability of simple changeover of machining sequence or from machine to machine. ●Lower cost because less time is required for programming. 计算机辅助编程有以下几个优于人工方式的重要优点。 ●比较容易使用的符号语言

●缩短了编程时间。编程是一种容纳了大量关于机械特点和工艺变量数据的一种能力，例如动力，速度，进给，刀具形状，刀具形状改变的补给量，刀具磨损，偏转，以及冷却液的使用。 ●减少了在人工编程中出现人为错误的可能性。 ●因为编程时所需更少的时间，降低了成本。

The use of programming languages not only results in higher quality but also allows for more rapid development of machine instructions, In addition, simulations can be run on remote computer terminals, to ensure that the program functions as intended. This method prevents unnecessary occupation of expensive machinery for debugging facility.

编程语言的使用不仅导致更高的工件质量而且考虑到了机械指令的更加快速发展。另外，模拟可以在远程计算机的终端设备上运行，这就确保了程序按照既定来运行。这种方法可以防止昂贵的机器由于调试程序产生不必要的占用。 Selection of a particular NC programming language depends on the following factors: 选择某一种数控机床编程语言主要取决于以下几个因素：

a)Level of expertise of the personnel in the manufacturing facility. 生产设施人员的专业水平级别 b)Complexity of the part. 工件的复杂程度

c)Type of equipment and computers available. 设备的外形以及计算机的应用 d)Time and costs involved in programming. 涉及编程的时间及费用

Because numerical control involves the insertion of data concerning workpiece materials and processing parameters, programming must be done by operators or programmers who are knowledgeable about the relevant aspects of the manufacturing processes being used. Before production begins, programs should be verified, either by viewing a simulation of the process on a CRT screen or by making the part from an inexpensive material, such as aluminum, wood, or plastic, rather than the material specified for the finished part.

因为数控涉及有关工件材料和加工参数的数据插入，编程必须由有制造业的相关方面知识的操作工和程序员来完成。在生产开始之前，程序应该被校验，还有通过一个CRT屏幕来观察工艺流程的模拟或者用廉价的材料制造工件，例如铝，木头或者塑料，而不是使用指定用于已加工零件的真实材料。 NC Part Programming Languages 数控编程语言

Probably over 100 NC programming languages hvae been developed since the initial MIT research on NC programming systems in

1956. Most of the languages were developed to serve particular needs and machines and they have not survived the test of time, However, a good number of languages are still in use today. In this subsection we review some of those which are generally considered important.

自从1956念麻省理工学院的初步研究数控编程系统以来大概有超过100种的数控编程语言已经被开发出来了。大多数语言开发用于特殊的需求和机械并且它们没有经受住时间的考验。然而，相当多的语言在今天一直被使用。在本小节，我们回顾一下那些被普遍认为是重要的语言。

APT(AUTOMATICALLY PROGRAMMED TOOLS). [/color]The APT languages was the product of the MIT developmental work on NC programming system. Its development began in june 1956, and it was first used in production around 1959. Today it is the most widely used language in the United States. Although first intended as a contouring language, modern versions of APT can be used for both positioning and continuous-path.programming and continuous-path programming in up to five axes.

APT(自动编程工具)，APT语言是麻省理工学院研发的关于数控机床控制编程系统的成果。它的研发开始于1956年六月，它第一次用于生产是在1959年左右。几天它是在美国应用最广泛的语言。虽然第一次打算作为一种轮廓语言。APT现在的版本可用于定位和持续路径的编程而且可用于多达五个基准轴的持续路径编程。

AUTOSPOT(AUTOMATIC SYSTEM FOR POSITIONING TOOLS).This was developed by IBM and first introduced in1962 for PTP programming. Today's version of AUTOSPOT can be used for contouring as well.

AUTOSPOT(用于定位工具的自动系统)。这个程序有IBM研发，在1962年第一次被引进用于PTP编程。AUTOSPOT现在的版本也可应被用于修证轮廓。

COMPACT Ⅱ.This is a package available from Manufacturing Data Systems,Inc(MDSI), a firm based in Ann Michigan. The NC language is similar to SPLIT in many of its features. MDSI leases the COMPACT Ⅱ system to its users on a time-sharing basis. The part programmer uses a remote terminal to feed the program into one of the MDSI computers, which in turn produe the NC tape. COMPACT II。这种语言是来自于制造数据系统的封装。（MDSI公司），在安阿伯，密歇根州的一家公司。数控机床控制编程的许多特点于SPLIT相似。MDSI公司将COMPACT II系统租赁给以分时为依据的用户。这种程序通过使用远程终端把程序传送给MDSI公司的计算机，有计算机转向产生数控的纸带。

ADAPT(ADAPTATION OF APT).Several part programming languages arebase directly on the APT program. One of these is ADAPT, which was developed by IBM under Air Force Contract. It was intended to provide many of the features of APT but to utilize a significantly smaller computer. ADAPT is not as powerful as APT, but can be used to program for both positioning and contouring jobs.

ADAPT（APT的改编版本）。多种编程语言直接依据于APT程序。这些语言之一便是ADAPT，它是在空军合同下由IBM公司研发的。这种语言意图提供许多APT的特点但是用于小型计算机。ADAPT不如APT一样强大，但是能够被用于定位和修改轮廓工作的程序。

EXAPT(EXTENDED SUBSET OF APT).This was developed in Germany, starting around 1964 and is based on the APT language. There are three versions; EXAPT Ⅰ-designed for positioning(drilling and also straight-cut milling ). EXAPTⅡ-designed for turning. and EXAPT Ⅲ-designed for limited contouring operations. One of the important features of EXAPT is that it attempts to compute optimum feeds and speeds automatically.

EXAPT(APT的扩展子集)。这种语言是由德国研发的。，开始于1964年之间，以APT语言为依据。有三个版本：EXAPT I ——被设计应用于定位（钻削和直切铣）。EXAPT II——被设计用于车削，还有EXAPT III—被设计用于限制轮廓的操作。EXAPT最重要的一个特点是尝试自动地计算最佳进给量和进给速度。

APT is not only an NC language; it is also the computer program that performs the calculations to generate cutter positions based on APT statements.

APT不仅仅是一种数控语言；它也是一种以APT声明为依据执行计算来。生成切割位置的计算机程序。 There are four types of statements in the APT language; 在APT语言中声明有四种类型：

Geometr statements. These define the geometric elements that comprise the workpart.They are also sometimes called definition statements.

几何声明。这些定义好的几何元素包括了工作组。它们有时也叫做定义声明。 Motion statements.These are used to describe the path taken by the cutting tool. 运动声明：这些都是用来描述切削刀具的切削路径的。

Postprocessor statements. These apply to the specific machine tool and control system.They are used to specify feeds and speeds and to actuate other features of the machine.

后处理程序声明。这些声明用于特殊的机械工具和控制系统。它们用于指定进给量和进给速度而且精确了机械的其他特点。 Auxiliary statements. These are miscellaneous statements used to identify the part, tool,tolerance, and so on . 辅助声明。这些不同种类的声明常用作定义工件，刀具，以及公差等等。

CNC programming of mills and lathes is like any other machine programming process; it requires a complete understanding of the programming language. The language used for NC of mills and lathes is often referred to as G-codes. The process used for milling machines and machining centers provides a good example of G-doce use because it emcompasses about 75 percent of all NC operations. The following five categories of programming commands and techniques are used for mill NC programming. 铣床和车床的CNC编程于其他机械编程工艺是相似的；它需要对编程语言有一个透彻的理解。这种用作铣床和车床NC的语言通常被称为G代码。这些工序通常用于铣床机械和机加工中心，提供了一些G代码使用的经典例子，因为它包括大约了NC操作中的75%。下面编程和工艺的五类用于铣床NC编程。

(1)Basic Commands.The following command codes and their fuctions are used to write on NC program for a noncomplex part. ●Motion commands(G00,G01,G02,G03) ●Plane selection(G17,G18,G19)

●Positioning system selection(G90,G91) ●Unit selection(G70 or G20, G71 or G21) ●Work coordinate setting (G92)

●Reference point return(G28,G29,G30) ●Tool selection and change(TXX M06)

●Feed selection and input(Fxxx.xx ,G94,G95) ●Spindle speed and control(Sxxx, M03,M04,M05)

●Miscellaneous funtions(M00,M01,M02,M07,M08,M09,M30)

(1)基础命令：以下的命令行代码和他们的功能是用来编写不复杂零件的数控程序： ●运动指令(G00，G01，G02，G03) ●平面选择(G17，G18，G19) ●定位系统的选择(G90，G91)

●单元选择(G70 或者G20，G71或G21) ●工作坐标系设定(G92)

●返回参考点(G28，G29，G30) ●选刀与换刀(Txx M06)

●进给的选择与输入(Fxxx.xx ，G94，G95) ●主轴转速与控制(Sxxx，M03，M04，M05)

●其他功能(M00，M01，M02，M07，M08，M30)

(2)Compensation and offset.The following commands are used to define work coordinate systems, perform tool diameter compensations, and compensate for tool length differences.

(2)补偿与偏置:下列指令用于定义工作坐标系系统，完成刀具走私补偿，不同刀具的长度补偿。 ●Work coordinate compensation(G54-G59) 工作坐标系补偿(G54-G59)

●Tool diameter(radius) compensations(G40,G41,G42) 刀具直径(半径)补偿(G40,G41,G42) ●Tool length offset(G43,G44,G49) 刀具长度偏置(G43,G44,G49)

(3)Fixed Cycles.These commands in the following three categories provide a method of executing a series of repetitive machining operations with asingle code block.

(3)固定循环:下列三类指令提供一种某种代码块的形式方式执行一系列的重复加工操作： ●Standar fixed cycles(G80-G89) 标准固定循环(G80-G89) ●Special fixed cycles 特殊固定循环

●User-defined fixed cycles 自定义固定循环

(4)Macro and Subrouting Programmine.Modern NC controllers support basic computer programming syntax that includes defined variables, arithmetic operations, and execution of logical decisions to define part geometry mathematically.

(4)宏程序及子程序：现代数控控制器支持基本的包括定义变量,算术运算,和执行合乎逻辑的零件几何定义的计算机编程语法。 (5)Advanced Programming Features.These are generally considered to be user-defined controls. (5)高级编程的优点：这些通常被认为是自定义控制。

A simple example of G-code programming illustrates how NC programming codes are used. 一个简单G代码例子说明了数控编程代码程序使用 Example 3-1

Write a G-code program to cut the path illustrated in Fig.3.0. with a cutter speed of 9 inches per minute(IPM) Solution:

N05 G90 Absolute coordinate system

N10 G00 X1.0 Y1.0 Rapid mode move to A(1.0,1.0)

N15 G01 Y6.0 F9.0 Linear interpolation, cut from A(1.0,1.0) to B(1.0,5.0) at a rate of 9 inches per minute N20 X7.0 Cut to C(7.0,5.0) N25 X1.0 Y1.0 Cut to A(1.0,1.0) 例3-1

下面写了一段G代码程序以9英寸/分钟的切削速度切削如图3.0所示的路径。 结果:

N05 G90 绝对坐标系统

N10 G00 X1.0 Y1.0 快速移到A(1.0,1.0)点

N15 G01 Y6.0 F9.0 直线插补，以9英寸/分钟的切削速度从A(1.0,1.0)点切削至B(1.0,5.0)点 N20 X7.0 切至C(7.0,5.0)点 N25 X1.0 Y1.0 切至A(1.0,1.0)点

Note that some commands in the previous example remain in effect after they are used. For example, X1.0 did not have to repeated in line N15 if the X distance did not change, and the Y distance was not needed in line N20 for the same reason.Also the feed rate was not repeated for lines N20 and N25 because no change in the cutting rate was desired. 注意:在前面的例子中使用过的指令仍保持着影响。例如：如果X的值没有改变那么X1.0在N15这行就不需要重复编写,同样的原因Y值在N20行可不写。同样在行N20和N25进给速度在切削时不需要改变故也不需要重复编写。 Manual Versus Automated Programming 自动化编程的人工指南

Programming of NC machines takes two forms: manual programming and code generation with the support of CAM software. Example 3-1 is an example of manual programming. Starting with a drawing of the milled part, the programmer creates a G-code sequence that drives the machine's cutting tool over the desired path. CAM-generated NC code uses a postprocessor for the target machining tool to convert the drawing of the part derectly to the G-code program that will run on the machine selected.The CAM software and pstprocessors fell into two catagories. One type, MasterCAM and Smart-CAM, is stand-alone and works with drawing files from all the major CAM vendors. The second type, developed by the CAD vendor, is integrated with the CAD program and runs as part of the integrated CAD/CAM design software.

NC机械编程采用两种形式：人工编程以及在CAM软件支持下的代码生成。例3-1是一个人工编程的例子。它以铣削零件图为开始，编程者设计一些能够驱动切削刀具沿着预期路径运行的G代码工序。CAM生成的NC代码为了使目标机械工具能够直接转换为零件图送给G代码程序运行在已选择的机械上，从而使用一个后处理程序。CAM软件和后处理程序分成两类。类型之一，专业CAM和简洁CAM，它是独立的，并且吸收了所有主要CAM供应商的绘图文件。第二种类型，是被CAD供应商研发的，它集成了CAD程序和运行，作为集成CAD / CAM设计软件的一部分。

Unit4

This chapter describes major developments in the design and capabilities of computer-controlled machine tools. Known as machining and turning centers, these machines have flexibility and versatility that other machine tools do not have, and they have, consequently, become the first choice in machine-tool selection. Machining and Turning Centers

It was noted that each machine, regardless of how highly it is automated, is designed to perform basically one type of operation. It has also shown that, in manufacturing, most parts require a number of different machining operations on their various surfaces.

本章描述了在设计和主要发展的能力,计算机控制的机床。被称为加工转身中心,这些机器有足够的灵活性和通用性,其它机床没有,而且他们,因此,成为第一个在台机床选择选择。车削加工中心和

它指出,每台机器有多高,无论它是自动的,是设计来执行基本上一种类型的操作。这也表明在制造业,绝大部分需要多个不同的磨削加工各种表面。

Note, for example, that the parts shown in Fig. 4.1 have a variety of features and that all surfaces on these parts require different types of machining operations, such as miring, facing, boring drilling, reaming, and threading, to obtain certain specified dimensional tolerances and surface finish.

Fig. 4.1 Examples of pans that can be machined on machining centers, using various processes such as turning, facing, milling, drilling, boring, reaming, and threading. Such pans would ordinarily require a variety of machine tools. (Toyoda Machinery) 注意,例如,部分如图4.1有多种功能,所有这些零件表面需要不同类型的加工操作,如miring、抛光、钻孔、铰孔和无聊编组,获得某种特定的空间公差和表面光洁度。

图4.1的例子可以在盘加工中心加工,运用多种过程,如车削、抛光、研磨、钻孔、镗孔、铰孔、螺纹。通常都需要一个这样的锅各种各样的机床。(机械)材料

Traditionally, machining operations are performed by moving the workpiece from one machine tool to another until all machining is completed. This is a viable manufacturing method that can be highly automated; it is the principle behind transfer lines. Commonly used in high-volume or mass production. Transfer lines consist of several machine tools arranged in a sequence. The workpiece, such as an automotive engine block, moves from station to station, with a specific machining operation performed at each station. The workpiece is then transferred to the next machine for another operation, and so on.

传统上,加工操作都由移动工件从一台计算机到另一个,直到所有工具加工完成。这是一个可行的制造方法,可以自动化程度高;它是生产线背后的理念。通常用于大批量或批量生产。传送带包括几个机床安排在一个序列。工件,如汽车柴油机机体、移动站一站,与一个特定的加工操作,执行每到一个车站。工件被调派到另一个操作下机等等。

There are products and situations, however, where transfer lines are not feasible or economical, particularly when the types of products to be machined are changed rapidly. An important concept, developed in the late 19S0s, is that of machining centers. A machining center is a computer-con- trolled machine tool capable of performing a variety of cutting operations on different surfaces and different directions on a workpieee (Fig. 4.2). In general, the workpiece is stationary and the cut- ting tools rotate, as they do in milling and drilling operations.

有产品和情况下,然而,在传送带不可行或经济,尤其是当的各类产品加工迅速改变。一个重要的概念,在开发S0s十九世纪末,是加工中心。一个加工中心机床——一个computer-con家中能够执行各种切削操作在不同的表面上,在一个workpieee不同方向(图4.2)。一般而言,静止不动、工件切割工具旋转,力谋像在铣削和钻削操作。 Fig. 4.2 A horizontal-spindle machining center, equipped with an automatic tool changer. Tool magazines can store 200 cutting tools. (Courtesy of Cincinnati Milacron, Inc.)图4.2一个horizontal-spindle加工中心,配备自动换刀系统。 工具杂志可以储存200刀具。(由辛辛那提Milacron股份有限公司)

The development of machining centers is intimately related to advances in computer control of machine tools, in general, a numerically controlled lathe (turning center) has two turrets carrying several cutting tools for turning, facing, boring, and threading.加工中心的发展进步密切有关计算机控制的机床,一般说来,数控车床(车削中心)有两个炮塔提着几刀具进行车削、抛光、无聊,线程。

The workpiece in a machining center is placed on a pallet or module that can be moved and swiveled (oriented) in various directions (Fig. 4.3). After a particular cutting operation has been completed, the workpiece does not have to be moved to another machine (as has been done traditionally) for additional operations, such as drilling, reaming, or tapping. In other words, the tools and the machine are brought to the workpiece.工件在加工中心放在一个托盘或模块可以移动和扭(导向)在不同的方向上(图4.3)。在一个特定的切割操作完成后,工件不需要移动到另一台机器上(已经)做另外的操作上,如钻孔、铰孔、攻丝等加工功能。换句话说,工具和机器将会被带到工件。

After all the cutting operations have been completed, the pallet automatically moves away with the finished workpiece, and another pallet containing another workpiece to be machined is brought into position by automatic pallet changers (Fig. 4.4). All movements are computer-controlled, and pallet-changing cycle times are on the order of 10 to 30 seconds. Pallet stations are available with multiple pallets serving the machining center. The machines can also be equipped with various automatic parts, such as loading and unloading devices.

在所有的切削操作完成之后,自动移动台车去完成工件和另一个托盘包含另一个工件加工带进位置换全自动托盘(图4.4)。采用计算机控制系统,所有动作周期时间是pallet-changing以10到30秒。托盘工位可与多个托盘为加工中心。机器也可以配备各种部件,如自动装卸设备。 此处缺少118~119 页

Note in Fig. 4.6 that several surfaces can be contacted, and that their relative positions are determined and stored in the database of the computer software. The data are then used to program tool paths and to compensate for tool length and diameter, as well as for tool wear in more advanced ma- chine tools. Types of Machining and Turning Centers注:在图4.6几种表面可以联系,他们的相对位置确定并储存在数据库的电脑软件。这些数据是可用于刀具轨迹,并赔偿程序对刀具的长度和直径以及更先进刀具磨损的马——中国的工具。类型的机械加工、车削中心

Although there are various designs for machining centers, the two basic types are vertical spindle and horizontal spindle; many machines are capable of using both axes. The maximum dimensions that the cutting tools can reach around a workpiece in a machining center is known as the work envelope; this term was first used in connection with industrial robots.尽管有各种各样的设计,对加工中心主轴的两种基本形式是垂直结构和水平的主轴,许多机器能够使用的两个轴。最大尺寸,刀具可达到在一个工件在加工中心被称为工作;这个术语信封首先用结合工业机器人。

Vertical-spindle machining centers, or vertical machining centers, are suitable for performing various machining operations on flat surfaces with deep cavities--for instance, mold and die making. A vertical-spindle machining center, which is similar to a vertical-spindle milling machine, is shown in Fig. 4.7. The tool magazine [3] is on the left of the figure and ail operations and

movements are directed and modified through the computer-control panel on the right.Vertical-spindle加工中心,或垂直加工中心,是适合进行各种磨削加工深腔的平面上,比如,模具制造。一个vertical-spindle加工中心,类似于一vertical-spindle铣床,是显示在图4.7。 工具杂志[3]在左边的图和蜗牛操作和动作导演和修改通过computer-control面板在右边。

Fig.4.7A vertical-spindle machining center. The tool magazine is on the left of the machine. The control panel on the right can be swiveled by the operator. (Courtesy of Cincinnati Milacron, Inc.)

Because the thrust forces in vertical machining are directed downward, such machines have high stiffness and produce parts with good dimensional accuracy. These machines are generally less expensive than horizontal-spindle machines.

Horizontal-spindle machining centers, or horizontal machining centers, are suitable for large as well as tall workpieces that require machining on a number of their surfaces. The pallet can be swiveled on different axes (Fig. 4.3 ) to various angular positions.Fig.4.7A vertical-spindle加工中心。 工具杂志在左边的机器。控制面板上右键即可扭的区域。(由辛辛那提Milacron股份有限公司)

因为驱动力在垂直向下,加工是针对这类机器有高刚度和使生产的零件具有良好的尺寸精度。这些机器通常比horizontal-spindle便宜的机器。

Horizontal-spindle加工中心加工中心,或水平,是适合大型以及工件加工高,需要大量的细胞表面。托盘可以扭在不同的轴(图4.3)各种角的位置。

Another category of horizontal-spindle machines is turning centers, which are computer-con-trolled lathes with several features. A three-turret computer numerical-controlled turning center is shown in Fig. 4.8. This machine is designed with two horizontal spindles and three turrets equipped with a variety of cutting tools used to perform several operations, on a rotating workpiece.另一个类别的horizontal-spindle机器转动中心,即:computer-con-trolled车床分别以不同的特征。 一个three-turret计算机数控车削中心。如图4.8。本机设计有两三个炮塔水平主轴,配备了各种刀具用来做几次手术,在一个旋转的工件。

Universal machining centers are equipped with both vertical and horizontal spindles. They have a variety of features and are capable of machining all surfaces of a workpiece (vertical, horizontal, and diagonal). Characteristics and Capabilities of Machining Centers普遍的加工中心配备两个垂直和水平锭子破损。他们有各种各样的特点和能力的所有表面的加工工件(纵向、横向、对角)。加工中心的特点和能力

The following are the major characteristics of machining centers:

* They are capable of handling a variety of part sizes and shapes efficiently, economically, and with repetitively high dimensional accuracy; dimensional tolerances are on the order of +_0.0025mm (0.0001 in. ).

* The machines are versatile, having as many as six axes of linear and angular movements, and are capable of quick changeover from one type of product to another, so the need for a variety of machine tools and floor space is significantly reduced.

* The time required for loading and unloading workpieces, changing tools, gaging, and troubleshooting is reduced, so productivity is improved, reducing labor requirements (particularly for skilled labor) and minimizing production costs.

* They are highly automated and relatively compact, so that one operator can attend two or more machines at the same time. * The machines are equipped with tool-condition monitoring devices for the detection of tool breakage and wear, as well as probes for tool-wear compensation and for tool positioning.

* In-process and post-process gaging and inspection of machined workpieces are now features of machining centers. 以下是加工中心的主要特徵:

*他们有能力应付各种各样的部分尺寸和形状的有效、经济、高尺寸精度和重复;空间容以+ _0.0025mm(0.0001英寸)。 *机器是多面手,有多达六轴角运动和线性和有能力转换快速从一种产品到另一个,所以需要各种机械工具和面积显著降低。 *所需的时间,改变工件装卸工具、测量,故障的减少,生产效率提高,减少劳动力需求(特别是熟练的劳工)和降低生产成本。 *他们的自动化程度很高,而且相对紧凑,使一人操作可以参加两个或两个以上的机器,在同一时间内。 *机器配备tool-condition监测装置检测刀具破损磨损,以及为tool-wear探针对刀具补偿和定位。 *过程和后处理加工工件的测量和检验现在特征的加工中心。

Machining centers are available in a wide variety of sizes and features, and their costs range from about $50,000 to $1 million and higher. Typical capacities range up to 75 kW (100 hp) and maximum spindle speeds are usually in the range of 4,000-8,000 rpm; some are as high as 75,000 rpm for special applications using small-diameter cutters. Some pallets are capable of supporting workpieces weighing as much as 7,000 kg (15,000 lb), although higher capacities are available for special applications.加工中心都可在各种各样的大小和功能,以及他们的成本范围从50000美元至100万美元甚至更高。典型的能力范围到75千瓦(100马力)和最大主轴速度的范围通常在4000 - 8000转/分钟;有些是高达75000转/分钟对于特殊应用利用小径刀。一些托盘能够支持工件重达7000公斤(15000磅),虽然较高容量可供特殊应用。

Many machines are now being constructed on a modular basis, so that various peripheral equipment and accessories can be installed and modified as the demand for different types of products changes.

Because of the high productivity of machining centers, large amounts of chips are produced and must be collected and

disposed of properly several designs are available for chip collection, one example of which is shown in Fig. 4.9. Note the two chip conveyors at the bottom of the cross-sectional view of a portion of a horizontal-spindle machining center. These particular conveyors are of the spiral (screw) type; they collect chips along the two troughs and deliver them to a collecting point. Other systems may use chain-type conveyors.许多机器正在建在一个模块的基础上,使各种锅炉周边设备及配件可以安装和改性的不同类型的产品需求的变化。

因为它具有极高的生产加工中心,大量的芯片生产和应收集和处理适当的几个设计资料采集芯片的一个例子,显示在图4.9。注意这两个芯片的底部输送带横向角度对这一部分horizontal-spindle加工中心。这些特殊的螺旋输送螺旋型);他们收集芯片沿两槽并送到一个收集点。其他系统可以使用链式输送机。

Fig. 4.9 Schematic illustration of a chip collecting system in a horizontal-spindle machining center. The chips that fall by gravity are collected by the two horizontal conveyors at the bottom of troughs. (Okuma Machinery Works Ltd. )

Machine-tool Selection 图4.9原理的演示采集系统在一个芯片horizontal-spindle加工中心。 芯片由重力秋天收藏两个横向输送带,底部的低谷。(Okuma机械厂有限公司) 台机床选择

Machining centers can require significant capital expenditures, so to be cost effective, they generally have to be used for at 1east two shifts per day. Consequently, there must be sufficient and continued demand for products made in machining centers to justify this purchase. Because of their inherent versatility, however, machining centers can be used to produce a wide range of products, particularly with just-in-time manufacturing [4]. The selection of the type and size of machining centers depends on several factors, among Machining and Turning Centers which are the following: * The type of products, their size, and their shape complexity

* The type of machining operations to be performed and the type and number of cutting tools required * The dimensional accuracy required * The production rate required

Although versatility is the key factor in the selection of machining centers, these considerations must be weighed against the high capital investment required and compared to the costs of manufacturing the same products using a number of more traditional machine tools.

加工中心就需要大量资本支出,因此,为了有效成本,他们通常用于在1东两班每天。因此,必须有足够的不断需求,使得产品在加工中心印证了这一收购。因为它们内在的多才多艺,然而,加工中心可以用来生产各式各样的产品,特别是和准时化生产[4]。选拔的类型及大小的加工中心取决于几个因素,在加工、车削中心通常是以下几点: *的产品类型的不同,他们的大小和形状的复杂性

*类型的加工操作执行的类型和数量和各种刀具的要求 *尺寸精度要求 *产率要求

尽管多样化是最关键的因素在选择加工中心,这些考量必须权衡比较高资本投资需求的费用制造同样产品的使用许多更加传统的机床。

Notes:

1. Tools are identified by coded tags. bar codes, or memory chips attached directly to the tool holders.

2. Touch-probes can be automatically installed into a tool holder to determine reference surfaces of the workpiece, for the selection of 1:oo3 settings, and for the on-line inspection of parts being machined.

接触式探针可以自动装入工具夹持口中，以确定工件的参考平面，以便对刀具设置进行选择，并对加工的部件进行在线检查。 3. tool magazine 多刀刀库

4. just-in-time manufacturing 及时制造 5

Part2 Unit05 Industrial Robot Introduction 介绍

Industrial robots are relatively new electromechanical devices that are beginning to change the apearance of modern industry. Industrial robots are not like the sicence fiction devices that possess human-like abilities and provide companionship with space travelers. Research to enable robots to \fruit. However, the current technoloty of industrial robots is such that most robots contain only an arm rather than all the anatomy a

human possesses. Current control only allow these devices to move from point to point in space, performing relatively simple taskes. The Robotics Institute of America defines a robot as \tools, or other specialized devices through variable programmed motions for the performance of a variety of tasks.\center would be qualified as a robot if one can interpret different types of machining as different function. Most manufacturing engineers do not consider a NC machining cernter a robot, even though these machines have a number of similarities. The power drive and controllers of both NC machines and robots can bw quite similar. Robots, like NC nachines can be either open-loop or closed-loop. In fact, many of the developments used in robotics have evolved from the NC industry, and many of the manufacturers of robots also manufacture NC machines or NC controllers.

工业机器人是相对来说较新的机电设备，它已经开始改变现代工业的面貌。工业机器人不像科幻小说中的那个模样具有人一样的能力并且能与其它移动物建立友谊。机器人能够看见听到触觉听的研究已经进行了20多年，现在开始开花结果了。然而，通常所说的工业机器人技术是是大多数机器人只包含了一条臂而不是拥有人解剖学上的全部结构。通常的控制只允许这些机器人在空间上从点到点的移动，完成相对简单的工作。美国机器人学会定义机器人为“一个可再编程序，多功能的机器手，它通过各种可编程的运行来完成不同的任务，用于搬用原料、零件、刀具、以及专用装置。如果认为不同类型的加工有不同的作用。那么一个数控加工中心也可以被认为是机器人。大部分制造工程师认为数控加工中心不是机器人，尽管他们有很多相似之处。数控机构和机器人的动力驱动和控制十分相似。想数控机构一样机器人能够由发动机、液压系统、气压系统提供动力。两种设备都能由开环控制或闭环控制。实际上，许多应用于机器人发展技术由数控工业演变过来并且许多机器人制造商也制造数控机床和数控控制器。

A physical robot is normally composed of a main frame(or arm) with a wrist and some tooling (usually some type of gripper) at the end of the frame. An auxiliary power system may also be included with the robot,A controller with some type of teach pendant ,joy-stick, or key-pad is also part of the system. A typical robotic system is shown in Fig.5.1。

物理机器人由带有腕（或称为臂）的主机身和机器端部的工具（通常是某些的支撑器）组成。机器人也可能有一个辅助动力系统。机器人系统还包括一个有一些控制环模、操作杆、键的控制器。一种典型的机器人系统如图5.1

Robots are usually characterized by the design of the mechanical system.A robot whose main frame consists of three linear axes is called a Cartesian robot. The Cartesian robot derives its name from the coordinate system. Travel normally takes place linearly in three-space. Some Cartesian robots are constructed like a gantry to minimize deflection along each of the axes. These robots are referred to as gantry robots. Fig.5.2 shows examples of Cartesian robots. These robots behave and can be controlled similarly to conventional three-axis NC machines. Gantry structure are generally the most accurate physical structure are for robots. Gantry robots are commonly used for assembly where tight tolerance and exact location are required.

机器人特点通常由机械系统的设计表现，一个主要框架包括三条移动轴的机器人称为笛卡尔机器人。笛卡尔机器人它的名字来源于笛卡尔坐标系沿三维空间的直线移动。一些笛卡尔机器人由龙门结构构成以便使沿每个轴的偏差最小。这些机器人称为龙门机器人。图5.2展示了笛卡尔机器人，这些机器人的动作控制都相似于传统的三坐标机床。龙门结构一般来说是最正确的机器人实际结构。龙门机器人通常用于公差较小和位置度要求较高的装配中。

A cylindrical robot is composed of two linear axes and one rotary axis. This robot drives its name from the work envelop(the space in which it operates), which is created by moving the axes from limit to limit. Fig.5.3 show typical cylindrical robots. Cylindrical robots are used for a variety of applications, but most frequently for material-handling operations.

圆柱机器人由两个移动轴和一个旋转轴组成，这种机器人的名称来源自包围轨迹（它的功作范围），它由轴移动的极限位置构成。图5.3展示了典型的圆柱机器人。圆柱机器人有许多应用，最常见的是材料的搬运操作。 Programming a Robot 给机器人编程

In order for a device to qualify as a robot, it must be easily reprogrammable. Nonprogramable mechanisms, regardless of their potential flexibility by reassembly or rewiring, do not be qualified as robots. A class of devices that fit this category are fixed or variable-squence robots, Many of these robots are pneumatically driven.Rather than controlling the robot path,the device is driven to fixed stops or switches via some form of ladder logic. Although the ladder programming qualifies for the deifnition of a robot, the switches or stops must normally be physically moved in order to alter the tasks being performed. Drive actuators or motors are turned \limited to rather simple applications.

为了是设备具有资格作为机器人，它必须是容易可再编程的。不可编程的机构，无论其通过重新装配或再接线可实现的潜在柔性有多大，也不能算作机器人。许多这类设备是固定的或可变的序列机器人。很多这样的机器人是由气压驱动的。这种机器人借助某种梯形逻辑图被驱动至一些固定的挡块活行程开关处，而不是控制它的轨迹。虽然梯形图编程可满足机器人的运动要求，但行程开关和挡块必须正常的被整体移动，以改变所需执行的工作任务。动力开动或发动机打开到“开”或“关”依据工序的要求和转换状态。机器人对这类系统操作通常局限于相当简单应用。

Programming of more conventional robots normally takes one of three forms: (1)Walk-through or pendant teaching,(2)lead-through teaching, or (3) offline programming. Each robot normally comes with one or more of these types of programming system. Each has

advantages and disavantages depending on the application being considered. 传统机器人的程序通常采用以下三个形式之一：（1）操作器编程（2）导入式程序（3）脱机程序。每个机器人通常具有一个或更多这种程序类型的系统。每种形式的优缺点依不同的应用而不同。

Walk-through or pendant teaching or programming is the most commonly used robot programming procedure. In thise type of programming, a pendant that normally contains one or more joy-sticks is used to move the robot throughout its work envelope. At the end of each teach point, th current robot position is saved . As was the case with NC machines, some robots allow the programmer the option of defining the path between points. Again, these robots are called continuous-path systems. Systems that do not allow the user to specify the path taken are called point-to-point systems. Many conntinuous-path robots allow the user to define the path to be taken between successive points. That is ,the user may define a straight-line,circular, or joint-interpolated path. In a straight-line path, the robots move between successive points in a straight-line in Cartesian space. Circular moves, as the name implies, take place in circles along one of the major planes. The path that the robot takes using a joint-interpolation scheme is not always easy to determine. In joint interpolation, each of the robot joints is moved at a constant rate so that all the axes start and stop at the same time. For Cartesian robots, straight-line and joint-interpolation schemes produce the same path. For the other types of robot systes, this is not true.

操作器编程最常用的机器人编程方式，这种类型编程，A pendant 通常包括几个用于使机器人在它工作范围移动的操作杆。在每个工序的终点，机器人的位置被保存。像数控机床一样，一些机器人允许编程人员选择定义两点间路线。另外，这些机器人被称为连续路径系统。不允许用户指定路径系统称为点到点系统。许多连续路径机器人允许用户定义在两个主要点之间连线的路径。那么，用户可以定义直线、圆弧的、指定某一位置的路径。在直线路径中，机器人在笛卡尔空间中，以直线两两端点移动。顾名思义，圆弧运动就是在某一主平面上沿圆弧运动。机器人以插入某处方案执行路线很不容易确定。在接点插补中，机器人的每一关节都以一恒定速度移动以保证所有的轴同时启动和停止。对于笛卡尔机器人，直线和结点插补方案产生相同的路径。对于其他类型机器人系统，这不成立。

Pendant programming systems normally have supplemental commands that allow the programmer to perform auxiliary opertaions such as close the end-effector, wait, pause, check the status of a switch or several switches, return a complete status to a machine,etc.The programmer walks the robot through the necessary steps requried to perform a task, saving each intermediate step along with the auxiliary information. The teach pendant used to program the Fanuc MI robot is shown in Fig.5.4

操作器编程系统通常提供允许编程人完成辅助操作的命令，如关闭终端，等待，暂停，检查一种或几种转换状态，返回全部状况给机床，等等。编程人员使机器人走过要求完成一项工作的必要步骤，保存每一中间步骤和辅助的信息。用于给Fanuc M1机器人编程的操作器，如图5.4所示。

Lead-through programming is one of the simplest programming procedures used to program a robot, As the name implies, the programmer simply physically moves the robot through the required sequence of motions. The robot controller records the position and speed as the programmer leads the robot through the operation. The power is normally shut down while the programmer is leading the robot through the necessary moves, so that the robot will not generate any \that might injure the operator. Although lead-through programming is the easiest programming method to learn, it does introduce some severe limitations to the robot's application. For instance,when the robot is being led through the operation, the operator carries the weight of the robot.The gears, motor and lead screw may introduce a false resolver reading, so that when the weight of the robot, and perhaps a part, must be supported by the system the actual end-effector position may be significantly different from the position taught to the robot.Another problem with this method is that since the position and speed are recorded as the robot is being led through the desired path, a significant amout of data are generated. This data must be stored and later recalled. Storage and retrieval space and time can cause the programmer problem. Perhaps the major problem associated with lead-through programming is that the human who leads the robot through the process is capable of only finite accuracy and may introduce inconsistencies into the process. Human-induced errors and inaccuracies eliminate some of the major advantages of using robots.

导入式程序是最简单的机器人程序设计过程之一。顾名思义，编程人简单实际的是机器人沿着路线轮廓移动。机器人控制器反馈它的位置并且像编程人一样引导机器人完成操作。当编程人员负责引导机器人完成必要动作时，动力降低以便机器人不产生伤害操作人员。尽管导入式编程是最容易学的程序语言，但它也反映了一些机器人应用的限制，例如，当机器人正在进行操作时，操作人员搬运机器人。齿轮，电动机和丝杠会引入错误的运算读数值，这样当机器人的重量，也许是工件的重量必须由系统承担时，端部执行器的 实际位置可能与机器人的训练位置有很大差异。这种方式的另一个问题是由于在机器人的位置和速度被记录指引通过期望的路径是，大量的数据信号产生，这些数据不需存储后调用，存储和从新调用的空间和时间可能会引起汇编器问题 ，也许与导入方程式协调的主要问题是引导机器人完成工艺过程的人能够做有限的准确可能引起工艺过程的不协调，人为错误和不准确性削弱了使用机器人的优点。

Offline programming for robots is a relatively new technology that provides several advantages over both lead-through and teach programming. The principles of offline programming are similar to using an offline laguage such as APT for NC programming. Several languages have been developed at major universities as well in industry throughout the U.S. Examples of these languages include VAL created by Unimation, AR-Basic by American Robot Corp.ARM-BASIC by Microbot, Inc, and AMI,by IBM. To

illustrate offline programming, AR-Basic will be used. AR-Basic allows the user to :

脱机程序对机器人来说是 相对较新的技术，它能够提供导入式和控制板编程的一些优点。脱机程序的规律与对数控技术应用脱机语言类似。几种脱机语言已经在美国的主要大学和工业种发展。这些语言主要有unimation的VAL,美国机器人协会的ar-basic,microbot,lnc的arm-basic和ibm的ami，以ar-basic为例解释说明脱机语言，ar-bisic允许用户： ?Define the position of the robot 定义机器人的位置 ?Control the motion of the robot 控制机器人的运动 ?Input and output control data 输入输出控制数据

AR-Basic is an interpretive BASIS system that employs many of the same function as the familiar BASIC programming language. In AR-Basic, points and tools are defined as a set of primitive data. Points are defined using the convention: X,Y,Z,R,P,Y

ar-basis系统的细化，他采用的许多相同的功能采用了我们熟悉的basic程序语言，在ar-basic中，点和刀具定义为初始化数据点由以下协议定义:X,Y,Z,R,P,Y

Where X,Y and Z are the Cartesian space occupied by the end-effctor, and R,P, and Y are the roll, pitch and yaw of the tool, Each of the point definitions can be specified as either absolute or relative points (again defined in a similar manner as for NC machines). X、Y、Z表示由端部执行器占据笛卡尔空间，r p y表示刀具旋转进给和yaw.每个点的定义既可以是绝对的夜可以是相对的（也和数控机床有相似的规则）。

Tool-definition commands are used to define the location of any tooling that might be required for an operation. The tool definition specifies the midpoint of the robot's faceplate, and consists of the same six data used to describe a point.

刀具定义命令常用于定义操作要求的所有刀具的位置，刀具定义指定机器人面板的中心，包括等定义点相同的六个数据。 The robot is set into motion useing a set of motion control commands. The motion commands allows the programmer to : 机器人通过运动控制命令执行运动，运动命令允许编程人：

＠Define the type of path to take(straight-line, circular, or joint-coordinated) 定义采取的路径类型（直线，圆弧，结点插补） ＠Define the end of tooling speed 定义刀具的最终速度 ＠Define the frame of reference 定义参考柜架 ＠Describe the current tool tip 定义刀尖的类别

AR-Basic also allows the programmer to input and output data to any device to which the robot is interfaced. Analog and digital data can be sent to A/D converters, D/A converters, parallel, or seial I/O ports. Table 5-1 contains Point and Tool definition examples. Table 5-2 contains AR-Basic examples for motion control.

AR-Basic也允许程序编译人员输入，输出数据到与机器人连接的设备，模拟的数字信号可以传送到模—数转换转换器并行的或串行的I/O口。表5—1是点和刀具定义的举例。表5—2举例说明了AR-Basic的运动控制。

Part02 Unit06 Group Technology 成组技术

Group technology is a manufacturing philosophy that involves identifying and grouping components having similar or related attributes in order to take advantage of their similarities in the design and/or manufacturing phases of the production cycleHistorically, this novel principle first came into being here in the United States in 1920,when Frederick Taylor supported the idea of grouping parts that required special operations.He was followed by the Jones and Lamson Machine Company in the early 1920s,which used a crude form of group technology to build machine tools.Their manufacturing approach involved such principles as departmentalization by product rather than by process and minimizing the routing paths.Today, group technology is implemented through the application of well-structured classification and coding systems and supporting software to take advantage of the similarities of components.

成组技术是一个制造业的哲学概念，它涉及到具有相似或相关属性零件的标识和分组，这样我们可利用产品的相似性这种特点，把这种技术应用于产品生产的设计制造过程中.历史上，这个新颖的理论是在1920年Frederick Taylor支持将需要特殊加工的零件成组而被第一次提出的.在1920年早期，Jones and Lamson公司继承他的思想，他们用粗糙的成组技术形式生产工具。他们使用这一原理的生产方法就是以产品来划分部门，而不是以工艺或缩短路径来划分部门。现在，成组技术正在通过运用结构分类、代码系统和支持软件来利用相似零件的优势进一步实施。 Reasons for Adopting Group Technology 采用成组技术原因

Modern manufacturing industries are racing a lot of challenges caused by growing international competition and fast-changing market demands. These challenges, which are exemplified in the following list, have been and can be successfully met by group technology: 现在制造工业正在接受由日益激烈的国际化竞争和多变的市场要求带来的挑战。这些挑战可以用成组技术成功地解决，如下所列：

◆There is an industrial trend toward low-volume production(small lot sizes)of a wider variety of products in order to meet the rising demand for specially ordered products in today's affluent societies. In other words, the share of the batch-type production in industry is growing day after day, and it is anticipated that 75 percent of all manufactured parts will be in small lot sizes.

◆工业生产发展的趋势是产品的品种更加多样而每种产品生产的数量减少，以此来满足当今繁荣社会不断增长的专门订货。换句话说，工厂中分批式生产的比例越来越高，预计将来全部的75%是小批量的。

◆As a result of the first factor, the conventional shop organization is becoming very inefficient and obsolete because of the wasteful routing paths of the products between the various machine tool departments.

◆作为第一个因素的结果，传统的车间机构变得越来越低效和过时，因为产品在不同的工具部传送的时候浪费时间。

◆There is a need to integrate the design and manufacturing phases in order to cut short the lead time, thus winning a competitive situation in the international market.

◆有必要把设计和制造的阶段集成在一起可以减少订货至交货的时间，这样可以在国际化市场上具有竞争力 Benefits of Group Technology 成组技术的优势

(1)Benefits in product design.Concerning design of products,the principal benefit of group technology is that it enables product designers to avoid \a product that was previously designed because it facilitates storage and easy retrieval of engineering designs.When an order of a part is released, the part is first coded, and then existing designs that match that code are retrieved from the company's library of designs stored in the memory of a computer, thus saving a large amount of time in design work. If the exact part design is not included in the company's computerized files, a design close enough to the required one can be retrieved and modified in order to satisfy the requirements,A further advantage of group technology is that it promotes standardization of production tools and work-holding devices.

在产品设计的优势。关于产品的设计，成组技术最主要的好处在于可以防止重复发明和复制工程成果。换句话说，由于它存储方便，并且相关的工程设计很容易被取出，所以消除了发明以前就存在的产品。一旦要求设计某一个零件，这个零件首先被编码，然后检索存储于计算机存储器中的该公司的设计库，找出与这个编码相匹配的已有设计，这样便可节省大量的重复设计时间。如果在公司计算机存储器中没有完全吻合的设计，那就找出与之最相似的设计，修正后可以满足要求。此外，成组技术可以促进生产工具和工件夹持装置的标准化。

(2)Standardization of tooling and setup.Since parts are grouped into families, a flexible design for a work-holding device(jig or fixture)can be made for each family in such a manner that it can accommodate every member of that family, thus reducing the cost of fixturing by reducing the number of fixtures required. Also, it is obvious that a machine setup can be made once for the whole family(because of the similarities between the parts of a family)instead of a machine setup for each of the individual parts.

加工和装配的标准化,因为工件被分成了类别，对工件夹持装置的灵活设计可以应用于每个类的所有零件，这样可以减少所需要的夹持件的数量，从而减少了夹持装置的费用,并且，很显然一次的机器装配可以用于此类的所有零件，而不是只对单个零件适用。

(3)More efficient material handling.When the plant layout is based on the group technology principles, i. e, dividing the plant into cells, each consisting of a group of different machine tools and wholly devoted to the production of a family of parts, material handling is more efficient because of the minimal routing paths of parts between machine tools achieved in this case. This is in contrast with the \illustrated in Fig.6.1,which indicates both cases.

更高效的物料输送,基于成组技术原理规划工厂布局，即把工厂分为单元，每个单元由一组用于生产同一族零件的各种机床组成，这时原材料的传送是很有效的，因为这种情形下的零件在机床间的移动路径最短,这与传统的按工序分部门的很乱的布局形成了对比！

(4)Improving economies of batch-type production.Usually, batch-type production involves a wide variety of nonstandard parts, seemingly with nothing in common. Therefore, grouping parts(and processes)in families enable to achieve economies that are obtainable only in mass production.

提高分批式生产的经济效益,通常，分批式生产包括各种各样的不标准零件，貌似它们没有共性，但是，分组技术只有在大量生产时才可以取得经济效益。

(5)Easier scheduling.Grouping the parts into families facilitates the task of scheduling, since this work will be done for each family instead of for each part.

更容易安排，将工件分族可以降低安排任务的难度,因为这些工作是面向族零件而不只是单个零件。

(6)Reduced work-in-process and lead time.Reduced work-in-process(WIP)and lead time result directly from reduced setup and material-handling time. In other words, parts are not redundantly transferred between machining departments, since material handling is carried out efficiently within each of the individual cells. This is in contrast to the production in a typical plant with a process-type layout, where a piece that requires only a few minutes of machining may spend days on the shop floor. This latter situation involves increased WIP, which adversely affects the inventory turuover and the cash-flow cycle. Also, lead time for a product manufactured in a plant designed according to group technology principles is far shorter than that of a product manufactured in a plant with a process-type layout.

减少在制品和订货至交货的时间，WIP源于减少了安装和原材料处理的时间，换句话说，由于在每个单元之间高效的物料输送，零件在加工部门传送地一点都不冗余这与本来一个工件可以几分钟加工完的却用了几天的基于过程布局的车间的生产形成了对比，后一种情形下需要较多的在制品，这对库存换新率及现金的周转率产生不利的影响，而且，基于成组技术的车间产品的订货至交货的时间比基于过程的车间快得多。

(7)Faster and more rational process planning.Group technology paves the way for automated process planning. This can be achieved through proper parts classification and coding system, where a detailed process plan for each part is stored under its code and thus can be easily retrieved.

更快更理智的过程设计，成组技术为自动过程设计做好了准备，这可以通过合理的零件分类和编码系统来实现，详细的加工计划储存在编码里面并且很容易被取出。

Factors preventing widespread application of group technology 阻止成组技术运用扩展的因素

(1) problems associated with rearrangement of physical equipment.As we saw, group technology is always associated with the concept of cellular manufacturing. The latter necessitates rearrangement of the existing physical equipment (machine tools) to form the cells. This, in fact, involves costly and cumbersome work, while is sometimes difficult to justify.

物理设备重新整理伴随的问题，我们知道，成组技术经常伴随着单元制造这个概念，后者需要对已有的设备重新改装才能形成这个单元，这个，实际上包括开销大的累赘的工作，有时很难调整。

(2) The large amount of up-front work needed.In order to implement group technology, it would seem that every single part in the inventory of the industrial corporation must be coded so that part families can be established. This appears to be a big task, which creates a barrier to any tendency toward implementing group technology. However, any manufacturing corporation actually deals with ordered and similar groups of parts because of the area of specialty of that corporation and/or its product line (i.e., rang of products). Accordingly, an appropriate approach for solving the problem of up-front work is to do that task gradually, by just coding the blueprints released to the workshop.As a result, the number of truly new (uncoded) parts released to the workshop tends to be leveled out after a short period of time.

需要大量的预先工作，为了实施成组技术，好像公司存货库的每一个零件必须编码，工件族才会建立，这是一个大的任务，对倾向实施成组技术的是一个障碍，然而，制造公司实际上是根据公司所在领域的特点或者其生产线来处理需要的零件组的，因此，解决前线的工作的一个合适的方法是对发布到车间的蓝图进行编码来逐渐的完成任务，最后，短时间之后发布到车间的没编码的工件的数量也来越少。

(3) Natural resistance to anything new.We as human beings try to keep away form the risky unknown. This very reason makes many managers and administrator avoid adopting new concepts and philosophies such as group technology.

天生对新事物的反对，我们人总是试图远离未知的东西。正是这个原因使得许多管理者拒绝采纳象成组技术这样的观念。 Classification and Coding of Parts 零件的分类与编码

In order to implement a classification and coding system based on group technoloty principles successfully, parts must be classified according to suitable features; then a meaningful code is assigned to reflect those features. The process of retrieving or grouping parts because of similar features therefore becomes a simple one. As a matter of fact, ZIP codes exemplify the basic features of a classification and coding scheme. The ZIP code indicates a geographic location by progressively classifying it into subdivisions, starting with the state and proceeding to the county, city, neighborhood, and street. Codes that are numerically close indicate locations that are, in reality, geographically close as well. In fact, it is this later particular feature that enables the formation of a family of similar parts based on only codes, without the need for physically examining the parts or their drawings.

为了成功地实现一个基于分组原则分类编码系统,部件必须以合适的特点进行分类,然后有意义的代码被分配去反映这些特征,因为零件的相似特征恢复和成组零件的过程变得简单了。事实上，ZIP 编码是基本特征分类和编码方案的一个例子，ZIP代码通过从国家到国家，城市，街道、街这样的逐步的分支机构指定一个地理位置，代码是数字上的接近指定位置，现实中也是地理上的接近。实际上，正是这种后期特殊的特性,使得组建一个基于只有代码的成组同类零件,而不需要物理上的检查零件或者图纸。

Although many classification and coding systems have been developed all over the world, none of them as yet has become a universally standard one. This is mainly because of the fact that a system must meet the specific need of the organization for which it has been developd. It is , therefore, the right approch to develop a group technoloty classification and coding scheme based on the specific needs of the client or to tailor an existing turnkey system to meet those needs.

尽管许多分类编码系统已被世界各地建立起来但是到目前为止它们中没有形成一种统一的标准，这主要是由于这样的事实,即一个系统它们被发展必须符合本组织的具体需要，因此，正确的发展一种成组技术分类及编码方案基于客户的特殊需求或者修改一种存在的管理系统去满足这一需求。

As previously mentioned, there are many benefits for group technoloty; these can fall within two main areas of application, design and manufacturing. Although it is always the ultimate goal to combine the advantages of group technoloty in both areas, this is usually very difficult to achieve, and the result is either a design-oriented or manufacturing-oriented system.

如前所述，成组技术是会给我们带来许多利处的。这些应用于两个主要领域。设计及制造。虽然成组技术的最终目的在于组合成组技术两个方面的优势，这通常是非常难实现的，结果要么是面向设计要么面向制造系统。

Construction of a coding system.A coding system may be based only on numbers or only on alphabets, or it can also be alphanumeric. When using alphabetical codes, each position(or digital location) can have 26 different alternatives, but the alternative values are only limited to 10 per position when numerical codes are used. Consequently, aplhabets are employed to widen the scope of a coding scheme and make it more flexible.

编码系统的结构：一种编码系统可以仅仅基于数字或只在字母,或它也可以字母数字。当使用字母的代码,每个位置(或数字位置)可以有26个不同的选择，当使用数字编码时每种选择值只能限制在每个位置只能放10个数字，因此,字母是被雇来扩大编码方案的适用范围,使其更有弹性。

There are basically two types of code constructions, namely, monocodes and polycodes. Monocodes which are also referred to as hierarchical or tree-structure codes, are based on the approach that each digit amplifies the information gived in the preceding digit. It is, therefore, obvioius that the meaning of each digit( or what a digit indicates ) is dependent upon the digits preceding it. Monocodes tend to be short and are shape-oriented. However, they do not directly indicate the attributes of components because of their hierarchical structure. Consequently, they are usually used for designing storage and retrieval and are not successful for manufacturing application.

基本上有两种类型的代码结构,即单代码及双代码，单代码基于将前面信息的每个数字放大的方法有时也叫做层次代码或者树结构代码，因此，显而易见,每一数字的意义(数字表明什么)是依赖于前面的数字。单代码一般倾向于短的代码及面向形状的代码。然而，因为他们的层次结构，他们没有直接注明零部件构件属性,因此,他们通常用于设计存储和检索和不成功的生产应用。

On the contrary, the meaning of each digit in a polycode is completely independent of any other digits and provides information that can be directly recognized from its code. For this latter reason the polycode is sometimes referred as the attribute code. The basic idea is illustrated in Fig.6.2, which indicates the way a polycode is structured. We can easily see that a polycode is generally manufacturing-oriented, because the easily identifiable attributes help the manufacturing engineer determine the processing requriements of parts. Moreover, a polycode involves a string of features, a structure that make it particularly suitable for computer analysis. Nevertheless, polycodes tend to be long, and a digit location must be reserved whether or not that particular feature applies to a part of a familly being coded. It is, therefore, a common industrial practise to use a disadvantages. In a combination type, the first digit divides the whole group of parts into subgroups, where shorter polycodes are employedl Also, in order to eliminate completely the possibility of error when coding a part, an interactive conversational computer program is employed, where the computer asks questions and automatically assigns a code for the part based on answers provided by the user at the computer terminal. An example of that automated coding is the MICLASS system(Metal Institute Classification System), which was developed by the Netherland's Organization for Applied Scientific Research and has gained industrial application in the United States during the last decade.

相反,每一数字的意义在双代码中是完全独立于其他数字和提供的信息可以直接从它的代码中确认，更多的，双代码包括一连串的特征，一种结构,使之特别适合于计算机分析，不过双代码倾向于长的代码，不管特殊的特征是否适用于成组被编码的零件的一部分一个数字位置都必须保留。因此，一些产业运用这一缺点，在一组合类型中，第一组数据将整组零件分成几个小组，此时也运用短的双代码。当对单零件进行编码时，为了完全忽略出错的可能，一种交互式会话计算机程序被采用，交互式会话计算机程序发出问题并自动地根据用户在电脑终端的回答为每个零件分配代码。自动编码的一个例子是,MICLASS系统(金属研究所分类系统),由丹麦就组织应用科学研究,并在美国过去的十年里获得工业的应用。 Design of Production Cells 单元产品的设计

It is time to see how a production cell can be designed.But,before doing so,we need to understand a new concept,namely,the composite part. This is a hypothetical part that has all attributes possessed by all of the individual parts of a family. Consequently,the processes required to manufacture the parts of a family would be all employed to produce the composite part representing that family,Any part that is a number of that family can be then obtained by deleting,as appropriate,some of the operations required for producing the composite partFig.6.3 illustrates that concept of the composite part consisting of all processing attributes of all the parts of the family,which are also shown in that figure.

现在是时候看看一个生产单元的设计。但是，在这样做之前，我们需要了解一个新概念，即复合材料零件。这是一个假设性的所有属性的一部分，已通过一个家庭的各个部分都具备。因此，制造过程需要一个家庭的部分将全部用于生产代表那个家庭的复合材料。任何部分，就是一个族零件数目可再删去得到 一些生产所需的复合材料零件。图6.3表明复合材料的所有组成部分的概念处理所有地区的族，这也是在该图所示的属性。

The next step is to design the machining cell to provide all machining capabilities based on the processing attributes os the composite part for the family of parts that is manufactured in the machining cell. The number of each kind of machine tool depends upon how frequently that machining operation is needed.In other words,the number of each kind of machine tool in a machining cell is not necessarily the same for all the different kinds of machine tools in the cell,After determining the kinds and number of machine tools in

the cell,the layout of machines within that cell is planned achieve efficient flow of workpieces through the cell,Of course,the cells are also arranged to gurantee easy flow of raw stock into the cells and finished the products out.

下一步是设计加工单元，提供所有加工处理属性的操作系统，为的是在族零件加工单元零件制造复合材料零件的能力。每个类型的机床数量取决于加工操作的频率换言之，每个机床加工中的一种细胞数目并不一定是所有机床在细胞中不同种类相同在确定的种类和机床细胞的数目，在该细胞是通过细胞计划实现高效的工件流布局的机器当然，还安排了细胞进入细胞，以保证原材料和成品库存易流动的产品。

Part02 Unit07 CAD/CAM/CAPP

CAD/CAM is a term which means computer-aided design and compuer-aided manufacturing. It is the technology concerned which the use of digital computers to perform certain functions in,design and production. This technology is moving in the direction of greater integration of design,and manufacturing, two activities which have traditionally been treated as distinct and separate functions in a production firm. Ultimately, CAD/CAM will provide the technology base for the computer-intgrated factory of the future.Computer-aided design(CAD) can be defined as the use of computer systems to assist in the creation, modification, analysis, or optimization of a design. The computer systems consist of the hardware and software to perform the specialized design functions required by the particular user firm.The CAD hardware typically includes the computer, one or more graphics display terminals,keybosrds, and other peripheral equipment.The CAD software consists of the computer programs to implement computer graphics on the system plus application programs to facilitate the engineering functions of the user computer. Example of these application programs include stress-strain analysis of components, dynamic response of mechanisms, heat-transfer calculations,and numerical control part programming. The collection of application programs will vary from one user firm to the next because their product lines, manufacturing processes, and customer markets are different. These factors give rise to differences in CAD system requirements.

CAD/CAM这个词条的意思是计算机辅助设计和计算机辅助制造。它是在设计和制造中运用,数字化计算机执行某些职能的技术。这项技术正在向设计制造更高的一体化发展。这两个在生产企业中被看作是截然不同的，相互分离的。最终，cad/cam将会提供给未来的计算机集成化工厂技术基础。计算机辅助设计可以定义为使用计算机系统来协助一个设计方案的形成，修改，分析及优化计算机系统由硬件和软件组成来进行公司特定用户需要的专门设计功能。cad硬件通常包括计算机，一个或多个图形显示终端，键盘，和一些其他的外围设备。cad软件是由计算机指令组成，他在系统中加上一些应用程序实施计算机绘图从而给用户电脑的工程功能提供便利。例如，这些应用程序包括应力应变分析组件，动态反应机制，热传递计算，和数控编程的一部分。该应用程序的内容将会随着企业用户的不同而变化，这是因为他们的生产线，生产工艺和消费者市场不同。这些因素导致对cad系统要求的不同。

Compuer-aided manufacturing (CAM) can be defined as the utilization of computer systems to plan, manage, and control the operations of a manufacturing plant through either direct or indirect computer interface with the plant’s production resources. As indicated by the definition, the applications of computer-aided manufacturing fall into two broad categories:

计算机辅助制造（CAM）可以被定义为利用计算机系统进行规划，管理和控制一个制造工厂通过计算机将接口直接或间接的计算机将接口和工厂生产资源，正如所指出的定义，计算机辅助制造的应用被归结为两大类；

(1) Computer monitoring and control.These are the direct applications in which the computer is connected directly to the manufacturing process for the purpose of monitoring or controlling the process.

电脑监测和控制:这些直接应用于计算机直接连接到生产工艺,监测的目的或控制这一过程。

(2) Manufacturing support applications.These are the indirect applications in which the computer is used in support of the production operations in the plant, but there is no direct interface between the computer and the manufacturing process.

制造业应用支持。这些都是间接的应用,计算机用于支持工厂的生产经营活动，但是电脑和制造的过程之间没有直接的接口。 Increasing Drafting Productivity 提高制图产量

CAD/CAM systems can entail a whole new set of drafting philosophies, all of which enhance productivity. For instance, most systems now on the market have a number of built-in functions that make new and useful drafting techniques automatically. Layering, for example, enables drafters to create drawing in logical segments that can be stored separately for easy identification; but the segments can still be output together , in one single piece , which illustrates the entire drawing at once. The method is analogous to the anatomical drawing we are all represented on individual overlays of clear plastic . They can be viewed individually , or ,by laying them on top of one another, all together , to show how the pieces fit in relation to one another . Layering with a graphics system uses the same principle except the overlays are logical rather than physical . The uses for this are myriad . Layer can be used to separate English and metric dimensioning information , inventory data , textual information , electrical requirement , plumbing ,machine tool paths, and a host of other things . The result is cleaner , less cluttered drawings .Another example of a productivity enhancement for drafting involve automating auxiliary views of a design . By pressing the right button or by entering the right command , a drawing

could be turned 90 degrees in one direction or anther . Three-dimensional designs could be rotated on any axis or displayed in any of several projections.

CAD/CAM可以推导出一整组全新的绘图原理，他们都能够提高生产率。例如，现在市场上大部分系统都有一些能自动生成新的有用的绘图技术的内置功能。例如，分层法能够使起草者在可以被分开储存易于识别的逻辑段内作图，但这些段仍然可以一起输出，在一个单独的片内就可以立刻显示整个绘图。这种方法类似于我们经常在生物练习上看到的解剖图，骨骼，神经，内部器官，血管和肌肉在绘图方面提高生产效率的另一个例子是自动生成设计图的辅助试图，通过按适当的键或输入正确的指令，设计图可以朝一个方向或另一个方向旋转90度，三维设计图可以绕任意坐标轴旋转，或显示其任意一个投影图。 The potential is really endless. Productivity increases are limited only when system management philosophies are limited. As an additional example, consider a drafting center for an architectural firm that specializes in designing warehouse. In such a situation, standard components of each drawing can be automated by creating macros.These macros are nothing more than a series of graphics system commands strung together and executed as a single unit to build, for example, a standard floor plan or a standard staircase, or a standard door and door frame.The system can do the work in seconds and the drafter is relieved from recreating that part of the design each time it must be inserted into a drawing.

这个潜力死无穷无尽的。只有当系统的管理理念是有限的才会限制生产率的增长。举另一个例子，想想一个专门从事设计仓库的建筑公司的起草中心，设计工作较多的是重复的，可以从一个工作转到另一个。在这种情况下，每张图的标准部件可由生成宏指令自动生成，这些宏指令只不过是一组串起来的绘图系统的指令，他们可以作为独立的单元来使用。例如，一个标准的平面图和标准的楼梯，或者一个标准的门和门框。这个系统可以在几秒钟之内做这个工作，起草者就不用再每次需要插图一个图的时候重新做那个部分的设计了。

Other macro programs could be useful.A set of commands might be put together that change the dimensioning of a drawing automatically from English to meteric units---or that automatically scale an entire drawing and rotate it to a deired orientation---or that generate a bill of materials list for complicated engineering drawings.

其他的宏程序可能是有用的。一组指令可能被组合在一起自动的把一个图纸的尺寸从英尺改成公尺或者是延展一整个图纸，把它旋转到预定的方向，或者生成一个复杂的工程图纸的材料清单。

To take it one step further, remember that enotire designs can be stored on the system.When the drafter receives a job that has specifications similar to a stored drawing, he merely retrives it, brings it into working storage, and edits those portions of the design that are not consistent with the specifications of the new job. Productivity increases are thus compounded. The original job is speeded up, and that job, in turn, is used to speed up the next job even further. This illustrates the need to maintain a complete and up-to-date data base that can be accessed easily by all users.

进一步说，整套设计方案可以保存在系统中，当起草者接到一份和他储存的设计极其类似的工作时，他只要把它检索出来，把它放到工作方案中，修改一下和这份新工作中不太相关的部分。从而加速了生产率的提高。原来的工作加快了，那个工作，反过来说又进一步加快了下一个工作，这说明有必要保持一个可以让用户轻松访问的完整的和最新的资料库。 Improving Design Analysis 提高设计分析

Design analysis is another important task that can be handled automatically by a properly integrate CAM/CAM system, This is particularly important in an application like piping plant design where drawing are often complex and must adhere to precise industry specifications. A AMD/CAM system with piping design application software give the user automatic feedback on such characteristics as fluid capacities, material chemistry, stress limitations, and coupling requirements. It can also generate orthographic plans, elevation data, equipment parts lists, cost estimates, flow diagrams, process and instrumentation diagrams, and bills of materials. The system can even access to and control complex engineering analysis programs and provide instant feedback on the viability of various design alternatives.

设计分析是另一个重要的任务可以由适当的整合CAM / CAM系统自动处理。这一点在像管道的工厂设计图纸,这样的应用场合是尤其重要的，工厂设计图纸往往复杂并且必须依附于精密工业的规格。用于管路设计的软件CAD/CAM 系统可自动为用户服务提供以下特性的反馈信息，如液体的容量、材料的化学特性、应力极限和连接要求等。它也可以产生平面布置图、立面资料、设备备件清单,成本计算、流程图表、流程和仪表图,和材料的费用。该系统甚至可以查阅及控制复杂的工程分析方案,提供即时反馈的各种设计方案的可行性。

These tools are avilable. It is up to industry to apply them and make them useful. Business is well advised to keep an open mind toward this technoloty and not to focus too narrowly on any one aspect of CAD/CAM. Current technology can do a lot more than just speed up creation of production drawings.

工具是有用的，这取决工厂工具的应用并使它有用。企业建议我们要保持开放的心态去面对这一技术而不是过于注重到了某一方面过于狭隘的CAD / CAM。现代的技术可以做实现很多功能而不仅仅是提高创建产品制图的速度。 Other Analytical Benefits 其他优势分析

CAD/CAM can influence a company's engineering systems in many other ways as well. It can streamline all physical processes, and permit reevaluation of current engineering methods and reporting procedures. CAD/CAM improves and expedites quality assurance

techniques, and it lends itself naturally to maintaining accurate and complete documentation and to keeping accurate records of part numbers and bills of materials.

CAD / CAM在许多其他方面也会影响公司的工程系统。它可以简化,并允许所有物理过程进行电流设计方案和报告程序。CAD / CAM改进和满足质量保证技术，它只用于保持零部件号和材料的费用自然的准确、完整的文件和保持准确记录。

The proper installation of fully integrated CAD/CAM system forces a company to evaluate all design and production methods and to begin appropriate standardization of those methods. Usually this evaluation proves profitable; but it can be traumatic for those who are unprepared. Management would be wise to keep both of these things in mind. The application of CAD/CAM is always a complicated business.

适当的安装完全整合的CAD / CAM系统强迫公司评估所有设计和生产方法并开始适当的标准化这些方法。通常此评价证明有利可图。但这对于那些没准备好的公司来说是会造成创伤的，管理层会明智的将把这些事情记在心里的。应用CAD / CAM永远是一种很复杂的业务。

What are the Drawbakcs 缺点是什么呢？

The drawbacks of CAD/CAM may not be so obviious, but they can be devastating even to the best plans. The most debilitating of these comes from the leap entailed in moving directly from mannual drafting and record keeping to CAD/CAM. It is like putting a jet engine in a Volkswagon. The car may go fast for a little while, but the whole thing will shake apart if the chassis is not reinforced sufficiently to handle the stress.

CAD/CAM的缺点或许并不明显，但即使对于最好的设计也是‘具有破坏性的。其中最大 的缺点是来自于从手工草图和保存的记录到CAD/CAM系统径直移动所必须的跳跃。这就好像是把喷气式飞机的引擎安装在大众汽车上，汽车开始可能在很短的时间内行驶的很快，但是，如果底盘不够坚固来处理作用力，那么所有的设计将震动分离。

In other words, CAD/CAM will highlight the inadequacies of the weakest areas of work. This can be brutal to the people and to the disciplines that cannot keep up. As one writter puts it:\being used poorly now, a CAD/CAM system will exacerbate the problem.\

换句话说，CAD/CAM将突出工作最脆弱的区域的不完全性，这对于人和不能保持的规则来说是残忍的，就像一个对它的描述：“如果一个公司内部对绘图材料清单和部分数字系统不能很好的使用，CAD/CAM系统将使问题恶化。”

When shcu unsatisfactory results occur, the finger is often pointed at the CAD/CAM system hardly a fair accusation, but it is usually more comfortable than pointing at people or organizations. Any computer will only be as the data put into it. It is the cardinal rule of data processing; garbage in, garbage out, If a company is utilizing an inadequate inventory control system. that system will not improve just because it is automated. The automatic in fact, will make the inadequacies much more glaring, and the result may be complete shaos. Therefore it is extremely important when implementing CAD/CAM not just to evaluate the needs for this technoloty, but to evaluate the existing disciplines it is expected to enhace.

当这种令人不满的结果发生时，通常会把矛头指向CAD/CAM系统---虽几乎是不能谴责的是，但通常比将矛头指向人或组织更好。任何一台计算机将只能在输入数据时工作，这是最基本的数据处理规则：废物进，废物出。如果一个公司正在使用一个不完全的目录控制系统，仅仅是因为它是自动的。这个系统将得不到改善。事实上，自动化将会使这个不完全更加明显。并且可能更混乱。因此当实施CAD/CAM系统是不仅评估技术的需要很重要，而且对于期望提高的现存的规则也是很重要的。 If management is unwilling to evaluate the existing operating conditions, standards, and procedures, the implementation of CAD/CAM is very likely to fail- for a number of compounding reasons.For one , management policies will be unorganized because the CAD/CAM system will be isolated from standard operation procedures. This will likely produce a growing feeling among low-level managers that the system can never be made useful to them. For another, no interdepartmental communication paths will have been established. This could result in the feeling that there is no long-term commitment to CAD/CAM. For still another, operatiors(the people actually using the system) will have had no input in the way the system was implemented. This leads to lack of drawing standards, poor system management, and alienation of system users. Such circumestances are sill almost certainly suggest improvements in those procedures even if the CAD/CAM system is never implemented.

如果管理者不愿对现存的操作条件，标准，工艺过程进行评估，那对CAD/CAM的使用将很可能会失败----因为一系列的原因。原因之一，管理政策将因为CAD/CAM系统与标准操作过程的分离而不能被很好的组织。在低水平的管理者中将产生一种这个系统永远不会被人们有效使用的感觉。另一个原因，不同的部门之间的信息通道还没有建立起来，这也导致产生CAD/CAM系统不能被长期使用的感觉。还有一个原因，就是操作员对系统实施的方面没有输入，这就导致了绘图标准的缺点，系统管理的贫乏，系统使用者的无知，这种循环是不可原谅的。特别是对于标准操作条件的评价将直接给提高这些工艺过程提供意见，即使是CAD/CAM系统从来没被使用过。 The Application of CAD/CAM CAD/CAM的应用

CAD/CAM technology has come a long way since SKETCHPAD, It is already being applied to a wide variety of different industries. It is used for everything from air traffic control to weapons research, from cartography to sports medicine, from circuit analysis to structural steel analysis. CAD/CAM is being applied to all aspects of drafting and manufacturing, from drawing sketches for movie

sets to directing enormous robots that assemble battleships. Its versatility is still being explored. 自从素描以来CAD/CAM已经经过了很长的一段路。它已经被应用于各种各样的不同的行业,它可用于从空中交通管制到武器研究，从制图到体育医疗，从电路分析到钢结构分析这一切场合。CAD / CAM正被应用于各方面的起草和制造,从为电影布景绘制图纸到指导大型机械人安装战舰。CAD/CAM的多功能性仍在被开发中。

The first application of CAD/CAM were mostly in electronics. This was because CAD/CAM was not an accepted technology beyond the confines of the computer industry itself. Slowly people began to realize the need for CAD/CAM in such markets as aeronautics, civil engineering, and architecture. The newer, more complicated designs were stretching manual drafting techniques begond the breaking point. CAD/CAM was the inevitable answer. By now the technology has a strong technological and financial base on which to work.Potential CAD/CAM users can afford to be picky about the systems.they finally purchase. There is no more excuse for buying a second-rate or inappropriate system.

CAD/CAM最初更多应用于电子类产品的。这是因为CAD / CAM不是公认的超越计算机工业本身范围的技术。渐渐地人们开始意识到在航空，土木工程，建筑这些市场中需要CAD/CAM。更新更复杂的设计超越了人工制图技术的突破点。CAD / CAM是不可避免的答案。此时，CAD/CAM技术所面向的工作也有很强的技术和经济基础。潜在的CAD/CAM用户对于他们最终支付购买的产品往往是很挑剔的。用户们没有理由购买一个二流的或者不合适的系统。 The CAD/CAM Marketplace Today 当今的CAD/CAM市场

Today there are 4 different kinds of CAD/CAM vendors in the marketplace. First are the subsidiary companies that sell CAD/CAM technology from within a department or division of a larger corporation. The CAD/CAM division of IBM is an example. as is McAuto, owned by McDonnell. Douglas; Calma, owned by General Electric; and Applicon, owned by Schlumberger, selling not only turnkey systems but acting as service bureaus. These companies are at their best when handling large accounts and providing service because they have such large resources from which to draw on . But they are also burdened with complex bureaucracies, which makes it difficult for them to react quickly to market trends or to incorporate into their product lines new technology developed outside their own research and development departments.

现在，市场上有4种CAD/CAM的提供商。第一种是大型公司的附属机构或部门。IBM的CAD/CAM分部就是一个例子。这些分公司和他的总公司哟着大宗的商业买卖，他们不仅销售钥匙系统，还称作售后服务处。因为这些公司有着强大的后盾，所以他们的运作良好。但是他们同样受束缚作风的影响，使得他们的不能对市场变化作出快速反应，也不能把先进的技术用于生产线来提高设备的性能。

Second are the established turnkey vendors. These companies offer a variety of CAD/CAM systems in various prince ranges for several different industries. These companies have been in CAD/CAM for 10 years or more and have established reputations in the development of new technology. Among the companies in this category are Computervision, Intergraph, and Autotrol Technology, These companies, because of their relatively smaller size, somtimes have trouble providing good serivce, but they react well to their customer's technology needs and can offer reliable, usable systems to a variety of industry segments.

第二种是专门的交钥匙系统销售商。这些公司提供各种各样的作用于不同工业环境的CAD/CAM系统。这些公司已经从事CAD/CAM行业几年或几十年。他们已经在不断的技术发展中建立了良好的 声誉，这类公司有计算机显示器公司，鹰图公司，和阿图组科技公司，这些企业由于规格较小，有时不能提供很好的售后服务，但他们对市场反灵敏，能很好的满足客户的要求，能够提供各种可以使用的CAD/CAM系统。

Third are the new, entrepreneurial CAD/CAM vendors. These companies tend to be small, young, and very innovative, Their combined market share is only about 5%, but each company excels in providing a single, high-quality system to a narrow market segment. Very often, entrepreneurial companies market minitor microsystems that are useful to customers with small and specialized CAD/CAM needs. Such customers are, in fact, well advised to purchase equipment from entrepreneurial CAD/CAM vendors.

第三种是新兴的CAD/CAM销售企业。这些公司比较小，年轻，富有创新精神，但他们的市场占有率仅为5%,但是每个公司都擅长为部分市场单人独特的高品质的系统。通常，这些企业销售的微型监控系统对需要小型化专业化 的CAD/CAM系统的客户非常有用。事实上，这些客户在购买设备前都是经过深思熟虑的。

Fourth are the service bureaus. These companies specialize in doing CAD/CAM work for other firms who have minimal or inconsistent needs. Service bureaus are becoming more and more prevalent and are often the best solution for companies who cannot afford their own CAD/CAM facilities or who are not yet ready to commit to such facilities. Service bureaus not only do CAD/CAM-related tasks, but they can conduct training classes and seminars for companies who may be contemplating the purchase of their own equipment in the future.

第四种是服务机构，这些企业专门从事CAD/CAM服务。来满足很小的或协调性的需求。服务机构越来越普遍并成为那些不能承担购买CAD/CAM系统费用或不具备购买条件的公司的首选。这些机构不仅参与CAD/CAM的相关商业行为，他们还能为那些将要考虑购买他们设备的企业进行相关培训和研讨。

Doing business with each of these vendor types has both benefits and drawbacks. Large companies are difficult to bargain with and slow to move their products toward the latest technology developments,but they generally provide good service and reliable

products.Established turnkey vendors are more flexible to individual customer's requirements and have shorter upgrade cycles, but they are susceptible to economic downturns and have difficulty servicing existing systems, The entrepreneurs sometimes have the best, state-of-the-art solutions for one or two narrow applications, but they often have very little management or marketing stability and can be risky investments. Service bureaus are good for small accounts, but cannot sustain a company with complicated CAD/CAM needs, It is up to each user to determine what kind of vendor is best, and it is important that potential customers understand what sort of a CAD/CAM vendor they are dealing with before they sign a sales contract. Dealing with the wrong kind of company, just as dealing with the wrong kind of system, can create long-term problems for the user.

和任一种这类供应商进行生意交易既有优点也有缺点。大型公司很难讨价还价并且面对新科技的发展产品转型也缓慢。但是他们通常会提供好的服务及可靠的产品，建立工程总承包供应商有更好的柔性满足个体客户的需求并具有较短的升级周期。但他们很容易受到经济衰退的影响,很难维修已经存在的系统,企业家对于一或者二个精密的应用有时有最好，最先进的解决方案。但他们经常很少进行管理或者了解市场稳定性而且可能进行高风险的投资。服务部门有良好的小额账户，但不能维持一个公司与复杂的CAD / CAM的需要。这是由每个用户确定什么样的供应商是最好的，潜在客户在签署一份销售合同时了解他们在和哪一类CAD/CAM供应商交易是非常重要的。签错了公司相当于签错了系统，会给用户带来长期的问题。

It is also to each vendor to determine which customers are best. The big and established vendors, for instatnce, tend to pursue accounts with Fortune 500 companies, While the competition may be fierce, they believe that it is to their benefit to sell large accounts which function to centralize these vendors' service requirements, reduce average installation costs, and generate greater potential for system upgrades. Other vendors, usually the smaller entrepreneurial type companies, would rather sell to a specific industry or industry group. This allows them to concentrate their research and development efforts on what they do best and know most about.

它也是每个供应商确定哪些客户是最好的。例如大的已经成立的公司倾向于追求财富500强的公司。竞争可能是很激烈的。但是他们认为销售巨额来集中这些供应商的服务需求、减少平均安装成本、,产生大的潜在系统升级对他们来说是有益的。其他供应商,通常较小的企业型公司,宁愿卖给某一行业或工业集团。这样允许他们集中精力研究和发展他们做得最好的懂得最多的产品。

Computer Aided Process Planning(CAPP) 计算机辅助工艺设计

Process planning is concerned with determining the sequence of individual manufacturing operations needed to produce a given part or product. The resulting operation sequence is documented on a form typically referred to as a route sheet. The route sheet is a listing of the production operations and associated machine tools for a workpart or assembly.

过程计划涉及决定需要生产给定的零件或产品工序的顺序。这个操作的结果序列被记录在一个表格上通常被称为路程表。路程表列出了工件或者装配体产品运作及相关机床工具应用的过程。

Closely related to process planning are the functions of determine appropriate cuutinr coditions for the machining operations and setting the time standards for the operations. All three functions-planning the process, determining the cutting conditions, and setting the time standard-have traditionally been carried out as tasks with a very high manual and clerical content. They are also typically routine routine tasks in which similar or even identical decisions are repeated over and over.Today,these kinds of decisions are being made with the aid of computers.

与过程计划密切相关的功能是确定恰当的切割加工操作和设置标准的时间操作，三种功能─规划过程、确定切割条件、设定标准时间─在习惯上被当作高度的手册和文书内容任务来实行。它们通常是相似甚至相同的日常任务每天不停的重复。今天，这些类型的决定是由计算机辅助完成的。 Traditional Process Planning 传统工艺计划

There are variations in the level of detail found in route sheets among different companies and industries. In the extreme, process planning is accomplished by releasing the part print to the production shop with the instruction \a more detailed list of steps describing each operation and identifying each work center.In any case, it is traditionally the task of the manufacturing engineers or industrial engineers in an organization to write these process plans for new part designs to be produced by the shop. The process planning prcedure is very much dependent on the experience and judgment of the planner. It is the manufacturing engineer's responsibility to determine an optimal routing for each new part deign. However, individual engineers each have their own opinions about what constitutes the best routing. Accordingly, there are differences among the operation sequences developed by various planners. We can illustrate these different dramatically by means of an example.

各公司和企业工艺卡的详细程序有差异。在极端情况下， 工艺设计仅仅是把写着\按图样要求加工\字样的零件图送到生产车间。大多数工厂有一个详细的步骤表， 以说明每顶操作及要点。在任何情况下，通常公司里的制造工程师或者工业工程师的任务就是为工厂生产的新产品设计这些工艺过程。工艺设计程序非常依赖于设计者的经验和判断。它是制造工程师的责任为每个新零件的设计确定最优的工艺顺序。然而每个工程师自身对于什么构成了最优的工艺过程有他们自己的想法。因此，不同的设计员会有不同的操作顺序。我们可以通过一个例子说明这一显著的差异。

In one case, a total of 42 different routing were developed for various sizes of a relatively simple part called an \There were a total of 64 different sizes ans styles, each with its own part number. The 42 routing included 20 different individuals had

worked on the parts; 8 or 9 manufacturing engineers, 2 planners , and 25 NC part programmers. Upon analysis, it was determined that only two different routings through four machines were needed to process the 64 part numbers. It is clear that there are potentially great differences in the perceptions among process planners as to what consitutes the \

在一个案例中，为一个相对简单的不同大小叫膨胀套管的零件设计工艺路线，总共设计出42种不同的工艺路线。共有64种不同的尺寸和样式，每种都有其自身的零件号。42条工艺路线中包括20个工人负责加工零件。8、9个制造工程师，2个设计者，以及25个NC零件程序员。综上分析，需要处理的64个零件号确定只种两种不同的路线通过四台机器。很明显,在关于是什么构成了“最佳”的生产方法这一认知过程，工艺设计员之间有潜在的巨大的差异。

In addition to this problem of variability among planners, there are often difficulties in the conventional process planning procedure. New machine tools in the factory render old routings less than optimal. Machine breakdowns force shop personnel to use temporary routings, and these become the documented routings even after the machine is repaired. For these reasons and others, a significant proportion of the total number of process plans used in manufacturing are not optimal.

除了设计者之间变化性这一问题，在传统的工艺设计步骤上也常常困难重重。工厂内的新机床采用缺少优化的旧工艺路线，机床故障迫使厂内工作人员采用临时工艺路线，这些即使在机床修理后也被当作文件工艺路线，出于这些和其它原因,绝大部分用于制造的工艺路线并非是最优的。

Automated Process Planning 自动化工艺设计

Because of the problems encountered with manual process planning, attempts have been made in recent years to capture the logic, judgment, and experience required for this important function and incorporate them into computer programs, Based on the characteristics of a given part, the program automatically generates the manufacturing operation sequence. A computer-aided process planning (CAPP) system offers the potential for reducing the routine clerical work of manufacturing engineers. At the same time, it provides the opportunity to generate production routings which are rational, consistent, and perhaps even optimal. Two alternative approaches to computer-aided process planning have been developed. These are :

因在人工工艺设计中遇到种种问题，在近几年工程师们为实现解决这些问题的重要功能并将这些功能融入到计算机程序中去试图收集所需的逻辑，判断及经验。根据给定零件的特征，系统自动产生生产操作顺序。计算机辅助工艺设计系统为减少生产工程师日常事务工作提供了可能。与此同时,它为产生理性的，稳定的甚至是最优的生产工艺路线提供了机会。目前有两种不同的计算机辅助工艺规划方法被开发出来，如下所示：

●Retrieval-type CAPP systems(also called variant systems 检索型CAPP系统（也叫多变系统） ●Generative CAPP systems 生产型CAPP系统 The two types are described in the following two sections. 以下两个部分介绍了这两种类型：

(1) Retrieval-type process planning sytems (1)检索型工艺设计系统

Retrieval-type CAPP systems use parts classification and coding and group technology as a foundation. In this approach, the parts produced in the plant are grouped into part families, distinguished according to their manufacturing characteristics, For each part family, a standard process plan is established. The standard process plan is stored in computer files and then retrieved for new workparts which belong to that family. Some form of parts classification and coding system is required to organize the computer files and to permit efficient retrieval of the appropriate process plan for a new workpart. For some new parts , editing of the existing process plan may be required. This is done when the manufacturing requirements of the new part are slightly different from the standard. The machine routing may be the same for the new part, but the specific operations required at each machine may be different。The complete process plan must decument the operations as well as the sequence of machines through which the part must be routed. Because of the alterations that are made in the retrieved process plan, these CAPP systems are sometimes also called by the name \

检索型CAPP系统使用零件分类编码和成组技术为基础。在这种方法中，在厂内进行生产的零件根据零件的制造特征被分成零件组。每个零件组都建立起一套标准的工艺路线。标准的工艺路线被存储于计算机文件中，并可取出用于生产新的属于同组的零件。某种形式的零件分类及编码系统对于组织计算机文件来说是需要的并且允许有效的为新零件检索出合适的工艺路线。对于新零件，其在各机床之间的运动路线可能是相同的，但是在每个机床上进行的加工操作可能不同。完整的工艺路线必须记录了零件的操作及通过每台机床的顺序。因路线是从取回的工艺路线中进行选择，这些CAPP系统有时也叫做\多变系统\。

Fig.7.1 will help to explain the procedure used in a retrieval process planning system. The user would initiate the procedure by entering the part code number at a computer terminal. The CAPP program then searches the part family matrix file to determine if a match exists. If the file contains an identical code number, the standard machine routing and operation sequence are retrieved from the respective computer files for display to the user. The standard process plan is examined by the user to permit any necessary editing of the plan to make it compatible with the new part design. After editing, the process plan formatter prepares the paper document in the

proper form.

图7.1将帮助我们解释一个检索型工艺路线系统中的应用步骤，操作者会在计算机终端输入零件代码数以初始化步骤，然后CAPP系统就会搜索成组零件父文件决定是否有相匹配的程序存在。如果文件包含一个相同的编码，标准的机床加工路线及操作顺序就会从各自的计算机文件中取出并显示给用户，操作者对标准的工艺路线进行测试并进行必要的修改以使路线更适应新零件的设计，编辑后，工艺路线格式以正确的形式准备纸型文件。

If an exact match connot be found between the code numbers in the computer file and the code number for the new part, the user may search the machine routing file and the operation sequence file for similar parts that could be used to develop the plan for the new part. Once the process plan for a new part code number has been entered, it becomes the standard process for future parts of the same classification.

如果在计算机的文件中找不到与新零件的编码完全相同的码，用户可在机床路径文件和操作顺序文件中查找类似的零件，用它来产生新零件的工艺路线。一旦新零件加工工艺路线代码数被加入到组零件工艺路线文件中，它就可以成为未来同类零件的加工工艺标准。

In Fig.7.1 the machine routing file is distinguished from the operation sequence file to emphasize that the machine routing may apply to a range of different part families and code numbers. It would be easier to find a match in the machine routing file than in the operation sequence file.Some CAPP retrieval systems would use only one such file which would be a combination of operation sequence file and machine routing file.

图7.1中，机床路径文件与操作顺序文件的区别在于前者强调机床的路径在一定范围内可适用于不同族的零件和不同编码的零件，故而搜索与机床加工路线文件相匹配的文件要比搜索操作顺序文件要容易得多，一些CAPP检索系统可能只用于组合了操作顺序与操作路线这类文件的检索。

The process plan formatter may use other application programs. These could include programs to compute machining conditions, work standards, and standard costs. Standard cost programs can be used to determine total product costs for pricing purposes.

工艺路线格式化程序可以采用其他的应用程序，这些程序包括程序计算工作标准、加工因素,与标准成本。标准成本计划可以被用来确定总产品成本价格的目的。

A number of retrieval-type computer-aided process planning systems have been developed. These include MIPLAN, one of the MICLASS modules, the CAPP system developed by Computer-Aided Manufacturing-International, COMCAPP V by MDSI, and systems by individual companies, We will use MIPLAN as an example to illustrate these industrial systems.

一系列的检索型计算机辅助工艺路线系统逐渐的发展起来，其中包括MIPLAN，MCLASS模块中的一种，CAPP系统由国际计算机辅助制造组织开发，数据系统V系统由制造数据系统公司开发，独立的公司分别负责系统的开发。我们将使用一个例子来说明这些MIPLAN工业系统。 Example 例子

MIPLAN is a computer-aided process planning package available from the Organization for Industrial Research, Inc, of Waltham, Massachusetts,It is basically a retrieval-type CAPP system with some additional features. The MIPLAN system consists of several modules which are used in an interactive,conversational mode.

MIPLAN是由麻萨诸塞州用于工业研究而开发的一种计算机辅助工艺设计包。它以检索型CAPP系统为基础并增加了一些特征。这MIPLAN系统由几个可用于交互式、会话模式的模块组成。

To operate system, the user can select any of four different options to create the process plan for a new part: 操作系统,用户可以选择任何四个不同的选项来为新零件创建加工工艺路线：

1)The first option is a retrieval approach in which the user inputs a part code number and a standard process plan is retrieved from the computer file for possible editing. To generate the part code number, the planner may select to use the MICLASS interactive parts classification and coding system.

1)第一个方法是检索方法在用户输入零件的码数和标准的加工工艺路线就可以直接从计算机文件中取出所需的工艺路线程序并进行可能的编辑。为产生零件编码,设计得目前可以选择使用MICLASS互动零件分类编码系统。

2)In the second option, a process plan is retrieved from the computer files by entering an existing part number(rather than a part code number). Again, the existing process plan can be edited by the user, if required.

2)第二个选顶，设计者通过输入一个存在的零件码(而不是一个零件代码数)直接从计算机文件中取出文件。如果有需要，这个已经存在的加工工艺路线可以进行再次的编辑。

3)A process plan can be created from scratch, using standard text material stored in computer files. This option is basically a specialized word-processing system in which the planner selects from a menu of text related to machines and processes. The process plan is assembled from text passages subject to editing for the particular requirements of the new part.

3)一个工艺过程计划可以通过使用储存在计算机文件标准的文本资料从零开始创建，这种方法实际是一个特殊的文字处理系统，设计员从该系统与机床和工艺有关的文本菜单中进行选择，对于有特殊要求的新零件的工艺堆积便通过编辑相关的文本文件中节段组合而成。

4)The user can call up an incomplete process plan from computer file. This occur when the user is unable to complete the process plan for a new part at one setting,For example, the planner may be interrupted in the middle of the procedure to solve some emergency problem. When the procefure is resumed, the incomplete plan can be retrieved and finished.

4)用户可以从计算机文件中调用一个不完整的工艺过程计划。这样的情况通常发生在当用户不能为通过一步设置就为新零件完成工艺路线设计，例如：用户可能在设计过程中途被打断而去解决一些紧急的事情，设计过程经保存后，未完成的操作可以被取出进而编辑完成。

After the process plan has been completed using one of the four MIPLAN options, the user can have a paper document printed out by the computer. A typical MIPLAN output is shown in Fig.7.2. It is also possible for the user to store the completed process plan(or the partially completed plan as with option 3) in the computer files, or to purge an existing plan from the files, This might be done, for example, when an old machine tool is replaced by a more productive machine, and this necessitates changes in some of the standard process plans.

通过使用上述四个MIPLAN选顶之一完成工艺设计，用户就可以从计算机中打印出纸质文件。一个典型的MIPLAN输出如图7.2所示。它也有可能为用户存储完成的工艺进程计划(或部分完成计划如选项3)计算机文件。或从文件中去清除一个现有的计划时,这是可能要做的工作,例如,当一个旧式机床取而代之的是更富有成效的机器,这对于一些标准的工艺进程计划来说是必要的修改。

Computer graphics can be utilized to enhance the MIPLAN output, This possibility is illustrated in Fig.7.3, which shows a tooling setup for the machining operation described. With this kind of prictorial process planning, drawings of workpart details, tool paths, and other information can be presented visually to facilitate communication to the manufacturing shops.

计算机图象学可以用来增加MIPLAN输出。这种可能性如图7.3所示。图中描述了一加工刀具配置运行情况，这种图案工艺规划，绘制的工件细节，刀具路径以及其他信息可以在视觉上显示方便与制造厂的交流。 (2)Generative process planning systems 生产型工艺设计系统

Generative process planning involve the use of the computer to create an individual process plan from scratch, automatically and without human assistance. The computer would employ a set of algorithms to progress through the various technical and logical decisions toward a final plan for manufacturing. Inputs to the system would include a comprehensive description of the workpart. This may involve the retrieval of existing standard plans. Instead, the generative CAPP system synthesizes the design of the optimum process sequence, based on an analysis of part geometry, material, and other factors which would influence manufacturing decisions. 生产型工艺设计包括运用计算机从零开始创建一个独立的过程工艺，自动地并且不需要设计人员的参与辅助。计算机采取一系列算法通过多方面的技术及逻辑判断以最终的制造工艺为目标发展进度。输入进系统的内容将包括对工件的全面描述。这可能包括检索的现有的标准的加工工艺，相反的,生产型CAPP系统以分析部分几何、材料和其他的因素会影响生产的决定为基础综合设计最优工艺序列。

In the ideal generative process planning package, any part design could be presented to the system for creation of the optimal plan. In practise, current generative-type system are far from universal in their applicability. They tend to fall short of a truly generative capability, and they are developed for a somewhat limited range of manufacturing processes.

在理想的生产型加工工艺设计包中，任何的零件设计都可以提交进系统去生成最优的工艺计划。在实际中，目前的生产型系统普通适用性与实际有所偏差，他们往往达不到一个真正的生成能力,他们开发出一种用于制造工艺比较有限的范围。 Benefits of CAPP CAPP系统的优点

Whether it is retrieval system or a generative system, computer-aided process planning offers a number of potential advantages over manually oriented process planning.

无论是检索型系统或生产型系统，计算机辅助工艺规划提供了超越手动的面向工艺过程规划的潜在优势。

(1)Process rationalization. Computer-automated preparation of operation routings is more likely to be consistent, logical, and optimal than manual counterpart. The process plans will be consistent because the same computer software is being used by all planners. We avoid the tendency for drastically different process plans from different planners. The process plans tend to be more logical and optimal because the company has presumably incoporated the experience and judgment of its best manufacturing people into the process planning computer software.

(1)流程合理化：计算机自动化操作路线的制备更可能与现实一致的，合乎逻辑的，比手工更加对口的。工艺设计的一致性在于相同的计算机软件被所有的设计所采用。我们避免从不同的设计者里产生显著不同的工艺方案的倾向。该过程的计划往往是更符合逻辑和最优的，因为公司已经大致地将公司内部最好的制造人员的经验和判断融入到计算机软件中。

(2)Increased productivity of process planners. With computer-aided process planning, there is reduced clerical effort, fewer errors are made, and the planners have immediate access to the process planning data base.These benefits translates into higher productivity of the process planners. One system was reported to increase productivity by 600% in the process planning function.

(2)提高生产率的过程规划：随着计算机辅助工艺规划的发展，有得减少文书工作，减少错误发生，并规划有直接访问数据库的工艺设计，计划制定者们能够立即获得工艺规划的数据基础。这些优点转化为更高生产力的设计过程，据报道，一个系统

增加了600％的过程中规划功能的生产力。

(3)Reduced turnaround time.Working with the CAPP system, the process planner is able to prepare a route sheet for a new part in less time compared to manual preparation.This leads to an overall reduction in manufacturing lead time.

(3)减少周转时间：使用的CAPP系统，流程规划者能为一个新零件制定与人工准备的路程周期表相比更短的时间作好准备。这就导致了一个全面减少生产准备时间。

(4)Improved legibility.The computer-prepared document is nearer and easier to read than manually written route sheets. CAPP systems employ standard text, which facilitates interpretation of the process plan in the factory.

(4)改进的可读性：计算机准备文件是阅读比手工编写的路线表更与实际接近且易于明白，CAPP系统采用标准文本，这有助于在工厂工艺方案的解释。

(5)Incorporation of other application programs.The process planning system can be designed to operate in conjunction with other software packages to automate many of the time-consuming manufacturing support function.

(5)其他应用程序的一体化:该工艺设计系统可以设计为与其他软件联合操作向自动化的耗时生产支持多功能.

增加了600％的过程中规划功能的生产力。

(3)Reduced turnaround time.Working with the CAPP system, the process planner is able to prepare a route sheet for a new part in less time compared to manual preparation.This leads to an overall reduction in manufacturing lead time.

(3)减少周转时间：使用的CAPP系统，流程规划者能为一个新零件制定与人工准备的路程周期表相比更短的时间作好准备。这就导致了一个全面减少生产准备时间。

(4)Improved legibility.The computer-prepared document is nearer and easier to read than manually written route sheets. CAPP systems employ standard text, which facilitates interpretation of the process plan in the factory.

(4)改进的可读性：计算机准备文件是阅读比手工编写的路线表更与实际接近且易于明白，CAPP系统采用标准文本，这有助于在工厂工艺方案的解释。

(5)Incorporation of other application programs.The process planning system can be designed to operate in conjunction with other software packages to automate many of the time-consuming manufacturing support function.

(5)其他应用程序的一体化:该工艺设计系统可以设计为与其他软件联合操作向自动化的耗时生产支持多功能.

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