可编程工作流程自动控制机床与设备开发与项目公关

机床电气化系统设计与友好界面的编程开发

A Model-Based Method to Develop PLC Software for Machine Tools

模型和模块化、流程化、智能化的机床用PLC开发仿真软件

It is difficult to develop PLC software for modern machine tools due to their increasing functionality and the resulting complexity. One approach to managing this is the model-based development and simulation-aided verification of control software. A suitable method for this is described in this paper. It focuses on a method for modeling the control functionality and a simulation system for commissioning the developed programs using a virtual model of the machine.

Application of PLC to dynamic control system for liquid He cryogenic pumping facility on JT-60U NBI system The control system of the cryogenic facility in the JT-60 NBI system has been replaced by employing the PLC (Programmable Logic Controller) and SCADA (Supervisory Control And Data Acquisition) system. The original control system was constructed about 20 years ago by specifying the DCS (Distributed Control System) computer to deal with 400 feedback loops. Recently, troubles on this control system have increased due to its age-induced deterioration. To maintain the high reliability of the cryogenic facility, a new control system has been planned with the PLC and SCADA systems. Their attractive features include high market availability and cost-effectiveness, however, the use of PLC for such a large facility with 400 feedback loops has not been established because of insufficient processing capability of the early PLC. Meanwhile, the recent progress in the PLC enables to use the FBD (function block diagram) programming language for 500 function blocks. By optimizing the function blocks and connecting them in the FBD language, the feedback loops have been successfully replaced from DCS to PLC without a software developer. Moreover, an oscillation of the liquid He level, which often occurs during the cooldown mode of the cryopumps, can be automatically stabilized by easily adding a new process program in the PLC. At present, the new control system has worked well.

现代液压设备用PLC系统快速准确开发

Design and implementation of look-ahead linear jerk filter for a computerized numerical controlled machine In this study, an open programmable logic controller (PLC) from Fuji electric prescribed in the Structured Text program was applied to develop a look-ahead linear jerk filter (LALJF) for a computerized numerically controlled (CNC) machine. To ensure the smooth and accurate motion of a tool with a linear change in jerk during real-time machining, the proposed filter was formed by combining a look-ahead algorithm with three modified moving average filters (3MMAF). The look-ahead algorithm performed a single look-ahead step-change in the speed of the speed curve. Based on a step-changing speed profile, given maximal acceleration/deceleration and maximum jerk, the speed curve was modified before it was passed through a linear jerk filter to reduce machining time. The speed commands filtered by the proposed filter stabilize machine table at the beginning and end of its motion, and at any point at which its speed exhibits a step-change. The theoretical and computational aspects of the LALJF are presented together with experimental results of its implementation on an X–Y table. The multiple-step-changing speed curve of a CNC machine and the speed curve of a high-speed measurement system were constructed in order to verify the feasibility and precision of the proposed method.

CNC与PLC集成协作方案

机床电气化系统设计与友好界面的编程开发

Can broadband over powerline carrier (PLC) compete? A techno-economic analysis

PLC面板友好界面与通讯过程分析

Powerline carrier (PLC) communications have been heralded by the FCC as the ―3rd wire‖ to every home, and have matured to the point of field trials and limited deployment. This paper examines the technology from a techno-economic perspective, factoring in regulatory issues and network design (focusing on the United States). Results indicate that PLC does not appear to represent a major disruptive technology, especially from a price-performance perspective. In addition, a baseline stochastic model created for the analysis shows that not only do competition and penetration matter, but locational distribution (i.e., how many consumers can share upstream equipment) is critical in determining PLC's competitiveness.

Design and construction of vacuum control system on EAST

可远程对服务器进行访问的PLC专用控制系统构建与设计 The construction of experimental advanced superconducting tokamak (EAST) was finished at the end of 2006 in Hefei, China. Its vacuum system, an important subsystem, has been commissioned in February 2006. The design and construction of this vacuum control system are described in this paper. The

requirements for remote automation, distributed control and centralized management, high reliability and expansibility have been taken into account in the design.

There are three levels of control in vacuum control system. The bottom level control is performed on the local instruments manually; the medium level control is based on Siemens S7-400 PLC; the top level control is conducted on IPCs with communication through profi_bus network. In addition remote handling and centralized monitoring could be realized by a remote control server.

Specifying and verifying PLC systems with TLA+ : A case study

PLC工作测试系统：案例研究

Abstract

We report on a method for formally specifying and verifying programmable logic controllers (PLCs) in the specification language TLA. The specification framework is generic. It separates the description of the environment from that of the controller itself and its structure is consistent with the scan cycle mechanism used by PLCs. Specifications can be parameterized with the number of replicated components. In our +

机床电气化系统设计与友好界面的编程开发

experience, the structuring mechanisms of TLA help to obtain clear, well-organized, and configurable specifications, finite instances of which are verified by the TLA model checker TLC. We have validated our approach on a concrete case study, a controller for fire fighting equipment in a ship dock, and report on the results obtained for this case study. ++

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF, which is a distributed control system aimed at stability and reliability of the pulse power supplies, PPS (Personnel Protection System) and MPS (Machine Protection System). The hardware environment is mainly based on PLC (Programmable Logic Controller), and ARM (Advanced RISC Machine) is also applied for studying

stability of the power supplies. WinCC and EPICS (Experimental Physics and Industrial Control System) have been selected as the platforms of SCADA (Supervisory Control and Data Acquisition). For unifying the interfacing to the control computer, all front-end equipments are connected via Industrial Ethernet.

The Development of Tools and Methods to Manage Residual Stresses in the Future Design of Nuclear Plant

能源电力企业的PLC安全化自动控制

1,2,3A long-term UK research programme on residual stresses was launched in 2004. It involves

Rolls-Royce plc and Serco Assurance, supported by UK industry and academia. The programme

involves the use of finite element analysis to simulate welding processes and supporting experimental validation using a variety of residual stress measurement techniques. 4

This programme is aimed at progressing the understanding of residual stresses in nuclear plant

components, whilst developing weld modelling analysis tools and residual stress measurement methods. These analysis tools will then be used to develop strategies to minimise welding residual stresses and distortions in the design and manufacture of future plant.

机床电气化系统设计与友好界面的编程开发

This paper describes the research that has been carried out to date and the tools and methods which are currently being used and developed to assist the engineer in determining the residual stress distribution in welded components as required by assessment procedures such as BS7910, R6 and FITNET. 567An overview of instrumentation and control systems of a Korea standard nuclear power plant: A signal interface standpoint

This paper presents an overview of instrumentation and control (I&C) systems of a pressurized water reactor (PWR) type nuclear power plant (NPP) in Korea. Yonggwang unit 3, which was constructed as a basis model for a Korea standard nuclear power plant (KSNP), is selected as an example for the

presentation. This overview is derived from analyzing the I&C systems based on a top-down approach. The I&C systems consist of 30 systems. The 183 I&C cabinets are also analyzed and mapped to the systems. The overview is focused on an interface between the systems and the cabinets. This

information will be used to understand the implementation of the I&C systems and to group the systems for an upgrade.

PLC-based system for oil rig control

One of the more challenging applications for a pump is the hazardous conditions on an oil rig out at sea.

A European oil and gas equipment manufacturer ensured that pump operators were safe by using a range of Bosch Rexroth products to remotely control its diesel engine-driven pumps.

Design and implementation of the BESIII detector-control system

In the upgrade project of the Beijing Electron-Positron Collider (BEPCII), a novel Detector-Control

System (DCS) for the Beijing Spectrometer (BESIII) has been built and started its successful operation for the BESIII Commissioning. The main task of the DCS is to monitor and control the status of the BESIII detector and to guarantee a safe operation of the detector. The DCS must provide a uniform and

coherent interface to detector operators even though there are a large number of distributed I/O channels from a large variety of equipments. For this reason, the DCS is hierarchically organized and divided into three layers: front-end layer (FEL), local control layer (LCL) and global control layer (GCL). In the FEL, devices ranging from simple sensors up to complex computer-based devices like embedded systems

机床电气化系统设计与友好界面的编程开发

and programmable logical controllers (PLC) are utilized. A LabVIEW-based software framework has been developed for the LCL. Network communication and web server technologies have been used for the GCL. This paper will give a detailed introduction to the design and implementation of the DCS. Its performance and reliability will also be discussed.

Tasks and structure of the WENDELSTEIN 7-X control system

The super conducting stellarator WENDELSTEIN 7-X will run pulses of up to 30 min duration with full heating power. Short pulses with arbitrary intervals, steady state long discharges and arbitrary

sequences of short phases with different characteristics in one discharge will be supported by the control system. Each technical component and each diagnostic system including its data acquisition will have its own control system permitting autonomous operation for commissioning and testing. During the

experimental sessions the activity of these devices will be coordinated by a central control system and the machine runs more or less automatically with predefined programs. A session leader program allows the leader of the experiment to choose and chain predefined segments, to start or stop a segment chain as a discharge. The progress of the discharge is shown by a sequence monitor attached to the central sequence controller and the session leader program.

W7-X has to be prepared for the experiment and monitored by means of the PLC based operational

management system. A safety system working independently of the operational management consists of local units responsible for the safety of each component and a central unit ensuring the safety of the

whole W7-X system. This safety system provides interlocks and controls the human access to the device.

A safety analysis is the basis for the development of the safety system.

Implementing total productive maintenance in Nigerian manufacturing industries Remarkable improvements have occurred recently in the maintenance management of physical assets and productive systems, so that less wastages of energy and resources occur. The requirement for

机床电气化系统设计与友好界面的编程开发

optimal preventive maintenance, using, for instance, just-in-time (JIT) and total quality-management (TQM) techniques, has given rise to what has been called the total productive-maintenance (TPM)

approach. This study explores the ways in which Nigerian manufacturing industries can implement TPM as a strategy and culture for improving its performance and suggests self-auditing and bench-marking as desirable prerequisites before TPM implementation.

A process and control simulator for large scale cryogenic plants

This paper presents a process and control simulator for industrial helium cryogenic plants controlled by Programmable Logic Controllers (PLC). This simulator can be used for different purposes such as operator training, test of the PLC programs or the optimization of the plant. The different component models used in the simulator are detailed and explained. Various large scale cryogenic plants used for the particle accelerator LHC (Large Hadron Collider) at CERN have been modeled and simulated. The good agreement between the simulation results and the dynamic behavior of real plants is demonstrated with experimental results. Various discussions complete the presentation.

CompactPCI/Linux platform for medium level control system on FTU

PLC与linux平台兼容 实现中型控制系统设计

In large fusion experiments, such as tokamak devices, there are common trends for slow control systems. Because of complexity of the plants, several tokamaks adopt the so-called standard model‘ (SM) based on a three levels hierarchical control: (i) high level control (HLC)—the supervisor; (ii) medium level control (MLC)—I/O field equipments interface and concentration units and (iii) low level control

(LLC)—the programmable logic controllers (PLC). FTU control system was designed with SM concepts and, in its 15 years life cycle, it underwent several developments. The latest evolution was mandatory, due to the obsolescence of the MLC CPUs, based on VME/Motorola 68030 with OS9 operating system. Therefore, we had to look for cost-effective solutions and we chose a CompactPCI-Intel x86 platform with

机床电气化系统设计与友好界面的编程开发

Linux operating system. A software porting has been done taking into account the differences between OS9 and Linux operating system in terms of inter/network processes communications and I/O multi-ports serial driver. This paper describes the hardware/software architecture of the new MLC system emphasising the reliability and the low costs of the open source solutions. Moreover, the huge amount of software packages available in open source environment will assure a less painful maintenance, and will open the way to further improvements of the system itself.

On the execution of sequential function charts

The transition between the supervisory control theory (SCT) and its implementation in programmable logic controllers (PLCs) is not straightforward. This is mainly due to the fact that the SCT is stated in an event-based asynchronous setting whilst PLCs are signal-based, synchronous and sequential. Based on Petri nets, the PLC programming language sequential function chart (SFC) seems to be the ideal choice for this transition. However, the transition requires detailed knowledge of how the PLC and SFCs work. Different execution models for SFCs are presented and compared with the international standard IEC 61131-3. Often, the application of the SCT to a control problem results in a set of modules between which mutual exclusion and synchronisation are important aspects. The results indicate, however, that for modular SFC programs it seems generally impossible to simultaneously achieve both mutual exclusion between modules as well as synchronisation of modules without using workarounds that may be either manual or suffer from state space explosion. Nevertheless, one of the presented execution models, the immediate transit/immediate action model, together with a handshaking procedure is shown to give a simple solution to both mutual exclusion and synchronisation.

Implementation of a fuzzy-based level control using SCADA PLC模糊控制方法 This paper presents a SCADA (supervisory control and data acquisition) control via PLC (programmable logic controller) for a fluid level control system with fuzzy controller. For this purpose, a liquid level control set and PLC have been assembled together. The PLC used in this work has no fuzzy module or software. The required fuzzy program algorithms are written by the author. Sugeno type fuzzy algorithm has been used in this study. To achieve the parameters of the membership functions, MATLAB/Simulink program has been used. PLC has been programmed using achieved fuzzy algorithm. A SCADA system has been composed for monitoring of water level in tank and position of the actuator valve. The main objective of this work is to present an implementation setup has been realized with no fuzzy logic controller module/software in this study. The system described in this paper is a low cost solution that is intended for control purposes. Simulation and implementation results have been compared and similar results obtained with a good degree of accuracy.

A data flow-based structural testing technique for FBD programs

PLC的数据流结构化程序设计与开发测试

With increased use of programmable logic controllers (PLCs) in implementing critical systems, quality assurance became an important issue. Regulation requires structural testing be performed for safety-critical systems by identifying coverage criteria to be satisfied and accomplishment measured.

机床电气化系统设计与友好界面的编程开发

Classical coverage criteria, based on control flow graphs, are inadequate when applied to a data flow language function block diagram (FBD) which is a PLC programming language widely used in industry. We propose three structural coverage criteria for FBD programs, analyze relationship among them, and demonstrate their effectiveness using a real-world reactor protection system. Using test cases that had been manually prepared by FBD testing professionals, our technique found many aspects of the FBD logic that were not tested sufficiently. Domain experts, having found the approach highly intuitive, found the technique effective.

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