Use of local area networks within manufacturing systems

Proposals have recently been made within the computer industry to standardize local area computer networking hardware and, although such standards are primarily aimed at the office automation market, they will undoubtedly find many applications in distributed industrial control where a requirement for high speed reliable standardized digital communications also exists. A simple manufacturing cell will be described which demonstrates the advantage of distributed control by using an integrated communications network employing low cost twin axial cable. The individual cell element control systems are supervised by a single computer station providing both control and management information. It will also be shown how such techniques can be applied within industrial manufacturing systems by considering the use of computer networks within a process plant and for the integration of industrial robot systems.     

Economic justification of computer control systems

Control of an industrial process can be described as making adjustments in certain manipulated variables in order to achieve well-defined objectives in the face of disturbances, using such measurements, control devices, and procedures as may be appropriate technically and justified economically.Where a computer control system is the appropriate solution to a process problem, a choice now exists between packaged systems for standard applications and custom systems to meet special requirements. Computer system costs may vary from $50,000 to as much as $8,000,000.Benefits from computer control are found in increased production, improved control of product quality, better use of raw materials, reduced operating manpower, and savings in capital investment. Simple examples illustrate the calculation of benefits from better quality control through increased production or reduced operating costs.The best criterion for evaluating a proposed computer control system is the expected return on investment (ROI) which allows consideration of the timing of income and expense items, as well as their magnitudes. This criterion also focuses attention on the need for effective project management.Published cost and benefit figures are given to show typical results obtained in actual control computer installations.     

Introduction to the special issue on Advances in intelligent nonlinear control for robotic systems

In the last two decades, robotic systems have achieved wide applications in every aspect of human society, including industrial manufacturing, automotive production, medical devices, and social lives. With the     

Computer simplification of formulas in linear systems theory

Currently, the three most popular commercial computer algebra systems are Mathematica, Maple, and MACSYMA. These systems provide a wide variety of symbolic computation facilities for commutative algebra and contain implementations of powerful algorithms in that domain. The Grobner basis algorithm, for example, is an important tool used in computation with commutative algebras and in solving systems of polynomial equations. On the other hand, most of the computation involved in linear control theory is performed on matrices, which do not commute, and Mathematica, Maple, and MACSYMA are weak in the area of noncommutative operations. The paper reports on applications of a powerful tool, a noncommutative version of the Grobner basis algorithm. The commutative version of this algorithm is implemented in most major computer algebra packages. The noncommutative version is relatively new     

工业控制计算机系统中若干问题的研究

伴随着现代化信息技术的高速发展,控制系统愈来愈成为网络与控制相结合的系统,关于这一领域的研究也成为一个前沿的课题.尤其是对于工业领域来说,计算机的应用将会带动其发生巨大的变革,从而朝着更为长远的方向发展.本文立足于这一现状展开讨论,并结合计算机在工业控制装置的应用过程当中产生的问题进行深入研究,进而提出相应的策略.     

Modelling for control analysis and design in complex industrial separation and liquefaction processes

Dynamic simulation of complex industrial systems is discussed, and a summary is presented of over a decade of work in the modelling, simulation and control of cryogenic separation and liquefaction processes. The work includes not only successful applications but also the development of tools to facilitate the construction of the simulation flowsheets and their effective use in control system analysis and design. The use of these tools and of two commercial dynamic simulation packages is reviewed. The question of what is a required level of modelling detail in dynamic simulation applications is addressed.     

Automated packing systems-a systems engineering approach

The ability to manipulate previously unseen objects under visual control is one of the key tasks in the successful implementation of robotic, automated assembly and adaptive material handling systems. The automation of such complex industrial environments will require the development of machine vision systems that are highly adaptable and capable of dealing with a wide range of variable products. An important group of applications of this type is found in the automated packing and nesting of arbitrary shapes. The aim of this work has been to produce an efficient packing strategy that is flexible enough for a wide variety of industrial uses and which can be implemented using fast moderately priced hardware. A systems approach, as distinct from a purely algorithmic one, has been deliberately adopted since the work is concerned with industrial vision applications in which significant problem constraints exist. This paper also outlines the background to this research, and reviews a selection of industrial packing applications. The packing procedure that has been devised, consists of two major components. The first is a geometric packing technique that is based on morphological image processing operations. This is used in conjunction with a prolog based heuristic packing procedure. Some of the factors considered at the heuristic level include shape ordering and shape orientation, both of which must be carried out prior to the implementation of the geometric packer. The heuristic procedures deal with problem constraints that are specific to a given application     

Using computer controlled physical models to analyze computer integrated manufacturing systems

It is usually difficult to design and install complex computer integrated manufacturing (CIM) systems without a large amount of time spent on debugging. In many cases miniature computer controlled physical models can provide information that reduces the time spent in the design and installation of larger systems. This paper describes how miniature physical models can be used to help industrial engineers design and install CIM systems.     

Electrophysiologically interactive computer systems

Combining computing with physiological sensing technologies will transform human-machine interaction and usher in a wide range of new applications. electrophysiologically interactive computer systems (EpICS) combine physiological sensing technologies with interactive computer applications. These systems support a diverse range of monitoring and training disciplines. EpICS provide interesting usability metrics and form the backbone of brain-computer interfaces, prosthetics, and other hands-free control technologies. We have identified two basic EpIC systems. Monitoring EpICS quantify or measure an electrophysiological signal of interest against some scale. Training EpICS feed back physiological information to a subject in real time to enable operant conditioning or instrumental learning of control to occur - a process commonly known as biofeedback     

Knowledge-based systems in computer-assisted production — a review

With the development of ‘expert’ or ‘knowledgeåsed’ systems, the efforts of artificial intelligence research have attained commercial application. While there have been to date, only a few investigations concerning the extent of this transfer, assessment of the extent of manufacturing applications has been mostly the result of speculation. By means of a comprehensive survey of documented systems in the USA, UK and FRG, the state-of-the-art of production applications of knowledge-based systems is described. Detailed discussion i is made of reasons leading to computer assistance and integrated solutions. Computer-assisted technological s systems are reviewed under their specific task areas — that is, construction and design, production planning, production control, production of parts, quality assurance, assembly, maintenance and customer service. Solutions for the connection of islands of automation are dealt with under the heading of Computer Integrated Manufacturing.     

Computer networks design using hybrid fuzzy expert systems

 Designing and configuring large computer networks to support a variety of applications and computational environments is difficult, as it not only requires highly specialized technical skills and knowledge, but also a deep understanding of a dynamic commercial market. Hybrid fuzzy expert systems integrate fuzzy expert systems and neural networks methods replacing classical hard decision methods and providing better performance than traditional techniques. In this paper, we present an integrated fuzzy expert system, machine learning, and neural networks approach to large structured computer networks design and evaluation. After presenting an overview of the system and the major research choices, we describe in detail the system's modules and present examples of its potential use.     

Simulation of industrial man-machine systems

In the design of large industrial processes, ergonomics designers can benefit from the use of computer simulation of man/machine systems when on-site studies are too risky or costly and laboratory studies alone have questionable generalization. This paper provides an illustration of this methodology for a hot strip mill in the steel industry and a demonstration of ergonomic design applications. A special simulation package which was developed for small military systems was adapted to this large industrial case and applied to an older manually-controlled mill of the 1930s. The simulation model was then modified to reflect automation and manning changes found in the mills built in the 1950s and the simulation results verified the actual performance differences between these mills. Experiments in further design and manning changes were made in order to demonstrate the usefulness of simulation as a design-aiding technique.     

Scheduling the monitoring of EDP controls in online systems

The aspects of internal control which troubles executives most is the increasing dependence of their organizations on computers for financial reporting and operational effectiveness. Given the growing number of computer applications, particularly those of a more complex nature—exemplified by data base management systems, distributed networks, and online processing—there is a need for tools to help in establishing and monitoring controls in such systems. To date, those who have addressed this issue have concentrated on models for choosing between alternative systems of control. In this paper, we address what we view as a more pressing issue—that is, the development of models to guide management and systems designers in establishing the frequency of monitoring internal controls. With the increased capability for embedding audit modules in the processing system, the question of frequency of monitoring becomes a concern in the systems design, itself.     

Pioneering work in the field of computer process control

Dreams of using digital computers in industrial control systems surfaced almost as soon as such a computer was invented in the mid to late 1940s. By the early fifties, the concepts of such use were fairly well established. However, actual applications had to wait until relatively small, reliable, and also relatively inexpensive machines were available, along with vendor companies with the will and the initiative to pursue this field vigorously Such a company was the Ramo-Wooldridge Company, which entered this field in the mid-fifties. The company found ready acceptance of its products among the companies in the process industries. By the mid-sixties, there were installations in almost every process industry and many other vendors had entered the field. Such installations became the norm for computer applications to industrial control until the microprocessor and its associated distributed computer control systems superseded them beginning in the mid-seventies. The article chronicles the development of this early field by describing several of the early installations and their successes and difficulties     

Development methods for trusted computer systems

Conclusion Well-designed computer systems can be safer than hardwired alternatives, and computer systems can control processes which are too complex for hardwired solutions, or where the hardwired solution is uneconomic.     

直流调速系统的LQSF*设计

改善调速系统的动态速降问题,早已引起设计和应用部门的重视,本文是从工程应用观点出发,用状态空间方法中的二次型线性最优调节器技术改进直流调速系统的新尝试,同时对系统的控制结构的合理性作了讨论。文中除了介绍基本型和无静差型LQSF调速系统外,作者还提出了一种新的无静差-低动态速降型LQSF调速系统控制结构。经过分析、计算机仿真和部分物理实验,证实这种新型调速系统无论在响应速度上,还是稳定裕量上都比目前通用的西门子方案“双环”调速系统优越,动态速降有大幅度的改进,且和稳定性的矛盾不大,同时噪声的影响也不大,很有工业推广价值。     

Using database machines in embedded computer systems

A discussion whether or not present database machine technology addresses the needs of embedded computer systems is presented. The interface between the embedded system and its environment tends to be complex, asynchronous, highly parallel and sometimes distributed. In addition, embedded systems are likely to have stringent resource requirements, both physical and logical. An answer to both the complexity issue and the resource limitation can be potentially found in the database machine.Functions are identified for two applications that the embedded system in general and the database machine specifically are asked to perform. Given the requirements of such applications the current database machine technology is evaluated.Finally, given the primary requirements of data security and system throughput of tactical embedded computer systems, a database machine using distributed architecture is proposed. The system has the potential for connecting multiple database machines to each host or for connecting multiple hosts to one database machine.     

Modeling Complex Real-Time and Embedded Systems—The UML and DORIS Combination

Real-time and embedded systems have widespread use in industrial, commercial and defence applications. They tend to be large and complex and need to focus on non-functional aspects such as performance, throughput and dependability. The UML has demonstrated potential for modeling real-time and embedded systems, but this potential can be greatly enhanced with the use of DORIS, a method extensively used in the aerospace industry. This paper considers how the two can be used in combination to model complex systems.