The basis of a comprehensive real-time knowledgebased system for control structure design and supervisory control is developed using the MUSE AT toolkit. Representation of control engineering knowledge as procedural ...
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The basis of a comprehensive real-time knowledgebased system for control structure design and supervisory control is developed using the MUSE AT toolkit. Representation of control engineering knowledge as procedural code in an object-based structure ensures that the knowledge base is easily understood and modified by domain experts. The simple learning capability that has been implemented has proved to be extremely useful and is being developed further as part of continuing research in this area. It is also hoped to extend the capabilities of the supervisory modules particularly in dealing with loop interactions, the prediction and diagnosis of faults and the provision of an intelligent operator interface.< >
The authors believe that there is considerable scope for the exploitation of rule-basedcontrol methods in industry and the paper describes their initial attempts at getting to grips with the ideas. The implementation...
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The authors believe that there is considerable scope for the exploitation of rule-basedcontrol methods in industry and the paper describes their initial attempts at getting to grips with the ideas. The implementation of rule-basedcontrol algorithms is considered for two very different types of process. The first involves the use of the 'ball and beam' apparatus which has been studied previously by a number of authors (Wellstead et al. (1978), Rees and White (1984)). The second project deals with the digital control of a marine diesel engine speed. In both cases, the control performance of a linguistic algorithm is compared to more traditional controller designs based on PID, modified deadbeat and state feedback methods.< >
The main objective of the approach outlined in the paper is the development of a real-time knowledge-based system which uses process and controlknowledge in the form of rules in conjunction with conventional algorith...
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The main objective of the approach outlined in the paper is the development of a real-time knowledge-based system which uses process and controlknowledge in the form of rules in conjunction with conventional algorithmic control for the enhanced supervision of fermentation processes. The system has been developed using the G2 Real-Time Expert System toolkit (Gensym Corp.) and runs on a SUN 3/60 workstation which is linked to pilot scale fermenters via an Ethernet connection to a IBM PS/2. The PS/2 carries out local monitoring and control of the fermentation process through an RS232 serial connection to a number of industrial signal processors which are in turn directly linked to the process.< >
From simulation results presented, it is been shown that the problem of rudder induced roll in modern warships can be overcome by using a suitable fuzzy controller. Whilst the fuzzy controller has proved successful, i...
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From simulation results presented, it is been shown that the problem of rudder induced roll in modern warships can be overcome by using a suitable fuzzy controller. Whilst the fuzzy controller has proved successful, it does not have any form of internal performance assessment which may be used to update its effectiveness. A self-organising controller incorporates a performance assessment mode during its operation. It is considered that such a controller would overcome the problem of having multiple output fuzzy options and has been the subject of ongoing research activity.< >
The author believes that industry is now entering a new era where on can realistically consider ways of not only achieving good product quality but can now coincidentally aim to optimise the process with respect opera...
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The author believes that industry is now entering a new era where on can realistically consider ways of not only achieving good product quality but can now coincidentally aim to optimise the process with respect operating parameters and procedures of the unit. The author considers how rule basedcontrol emerged out of the need to find a solution to controlling and optimising those processes that were known to be complex and difficult to model and yet not particularly demanding on the process operators. The techniques are now well established and the benefits arising out of its application have been shown to be much greater than originally targeted giving audited paybacks as short as three months. This is probably due to the formal combination of the pragmatic approach to control of the process operators with that of the technical experts in the form of process engineering and central technical personnel. The potential range of applications for rule basedcontrol is probably unlimited since in its simplest from it can be made to mimic conventional PID control and yet can be very easily extended to successfully handle a wide range of special or unique conditions.< >
In the work described in the paper the control of neuro-muscular blockade via relaxant drug administration to patients undergoing surgery is considered. Adequate levels of blockade are required to assist the surgeon p...
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In the work described in the paper the control of neuro-muscular blockade via relaxant drug administration to patients undergoing surgery is considered. Adequate levels of blockade are required to assist the surgeon perform an operation whilst minimising the risks of tissue damage. Relaxant drugs are conventionally administered via bolus injections determined by anaesthetists according to their clinical judgement. It has been found that, like many biomedical systems, the patient dynamics are nonlinear, time-varying and exhibit large inter-patient variability. Under such circumstances, the methodology of fuzzy logic control, introduced by Zadeh, may be suitable for such an application provided that a suitable rule-base can be elicited. Two approaches are presented, one of which employed a training simulator, and the other used logged data taken from an anaesthetist performing manual control of drug infusion.< >
Outlines the motivation, developments and achievements within ESPRIT project p820: Design and Experimentation of a Real-Time knowledgebased System Toolkit for Process controlapplications. The project has developed a...
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Outlines the motivation, developments and achievements within ESPRIT project p820: Design and Experimentation of a Real-Time knowledgebased System Toolkit for Process controlapplications. The project has developed a kernel of the toolkit, now called the QUIC Toolkit (QUalitative Industrial control) and is being validated on three important demonstrator applications relevant to industrial control and diagnosis problems. Within the QUIC Toolkit architecture five conceptual abstractions or layers have been defined: strategic, tactical, teleological, functional and object, each providing a set of primitives consistent with the given architectural properties.< >
Power stations are required to adjust their output continually in response to the demands of the National Grid. This requires, in particular, accurate control of the fuel flow to the boiler and of the governor valve w...
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Power stations are required to adjust their output continually in response to the demands of the National Grid. This requires, in particular, accurate control of the fuel flow to the boiler and of the governor valve which regulates the steam flow to the turbine. control of these parameters is generally considered together and referred to as Load control. Work has been carried out by the CEGB into improved methods of load control in order to achieve more rapid and predictable load changes and improved control near to plant constraints. This enables both power stations and the Grid System to be operated more efficiently and with less damage to the paint. In particular, a major project has been undertaken on a 500 MW coal-fired unit at West Burton Power Station. The paper considers the implementation of a rule-based technique to achieve improved control of the governor valves. This enables an operating region, where discontinuous governor valve movement occurs, to be avoided and thus achieves: better control of the generated output; and much reduced wear of the valve mechanism which is both expensive to repair and can only be serviced during periods of extended plant shut-down.< >
In the therapy of premature infants with respiratory distress syndrome, their arterial oxygen partial pressure is routinely controlled by adjusting the concentration of oxygen (F/sub 1/O/sub 2/) in the air they inspir...
In the therapy of premature infants with respiratory distress syndrome, their arterial oxygen partial pressure is routinely controlled by adjusting the concentration of oxygen (F/sub 1/O/sub 2/) in the air they inspire. For more severe cases where the patient is unable to breathe unaided, assisted ventilation is introduced to maintain the oxygen supply and carbon dioxide elimination. Multiple ventilator-controlled parameters, including peak inspiratory pressure, positive end-expiratory pressure, ventilation frequency, inspiratory to expiratory duration ratio, may be altered skilfully to optimize gas exchange. Various rules have been derived by paediatritions based on their clinical experiences. In the paper the authors discuss an expert ventilator manager combined with a real-time generalised predictive controller. The objective of the system is to control both blood oxygen and carbon dioxide pressures within their prespecified ranges by adjusting F/sub 1/O/sub 2/ and four ventilator factors.< >
Describes the design and implementation of a hierarchical control system for flexible assembly cells. The system is innovative for two reasons: it is implemented using object-oriented programming (OOP) techniques and ...
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Describes the design and implementation of a hierarchical control system for flexible assembly cells. The system is innovative for two reasons: it is implemented using object-oriented programming (OOP) techniques and it uses a product-centred control strategy. conventional robot control systems are either equipment oriented, where programs are sequences of commands to robots and grippers, or task based, in which the program represents a sequence of parameterised processes. The focus of attention is the product being assembled. it is argued that this leads to a simpler, more flexible and more intelligent control system. Finally, a prototype system implemented in KEF, an AI toolkit, on a symbolics Lisp machine is described.< >
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