Expert system for process control

A Real-Time Expert System for Process Control... 

An Expert System Approach to On-Line Optimization An Expert System for Process Control Toubleshooting (Prolog) Object-Oriented Integration in Process Engineering Computation Dynamic Simulation in the Construction of Expert Systems for Process Fault Diagnosis... 

The requirements for expert systems for process control have inspired new designs based on real-time knowledge base inferencing. Object oriented representation of plant equipment, knowledge representation of the interactions of processes and models of process behavior - heuristic as well as analytical --are incorporated into a real-time expert system for process control. The application of inference in real-time requires using metaknowledge to focus the inferencing resources of the expert system. Finally truth maintenance requires a temporal model of the time dependence of the truth of data and inferred results. 

Sargeant, R.A.E. Expert systems for process control rooms, Measurement + Control, pp.239-244, Nov 1986. 

Processing intelligent What is needed is to cut inefficiency, such as the variables, and in turn cut the costs associated with them. One approach that can overcome these difficulties is called intelligent processing (IP) of materials. This technology utilizes new sensors, expert systems, and process models that control processing conditions as materials are produced and processed without the need for human control or monitoring. Sensors and expert systems are not new in themselves. 

Myers, D. R., Hurley, C. E. and Davis, J. F. A diagnostic expert system for a sequential, PLC controlled operation, in Artificial Intelligence Applications in Process Engineering. (M. Mavrovoumolis, (ed.). Academic Press, New York, 1990. 

Most industrial control systems use the multiloop SISO diagonal control structure. It is the most simple and understandable structure. Operators and plant engineers can use it and modify it when necessary. It does not require an expert in apphed mathematics to design and maintain. In addition, the performance of these diagonal controller structures is usually quite adequate for process control apphcations. In fact there has been little quantitative, unbiased data showing that... 

Expert systems can also be used off-line as advisory systems. If some leeway is left in the process specifications, operators can even be instructed to make simple variations in the process. Hajicek developed an expert system for troubleshooting injection molding, which was designed to be used by operators to adjust controls as needed whenever part quality suffered [20], These expert systems do not necessarily plan an entire cycle. As we will see in the section on in-process control, however, they can be used to do so. There are even specifications that include rules for altering the cure cycle in response to the results of quality acceptance tests such as flow and volatiles, a primitive set of heuristics. 

Expert Systems, Metabolism and Pharmacolemetics Strate Gene, An Expert System for Use In Molecular Biology An Expert System Based Intelligent Control Scheme for Bioreactors An Intelligent System for the Design of Protein Recovery Processes... 

Expert Systems for Control of Plant Operations in Real Time Using Expert Systems to Monitor Safety Margins for High Hazard Processes... 

Highham, E.H. A different approach to self tuning in process controllers - the case for introducing an expert system, Meas. and Control, vol.19, pp.253-257, Nov 1986. 

The proposed methodology of complex A SW verification assessment was approbated during the expertise of a number state-of-the-art Ukrainian NPP I C systems. Particularly the proposed methodology was used during the expertise of computer-based control system ASUT-IOOOM for Zaporozhey NPP. It is system for automatic control of turbine. The developed approach ensures the possibility of unification and standardization of A SW assessment verification process. ASUT-IOOOM A SW verification and validation expert analysis consists of three stages. 

M.M. Stefanovic and M.B. Stakic, Fuzzy expert system for drying process control. Proceedings of the I2th International Drying Symposium IDS 2000, 2000. 

Chapters 9-16 cover the application of optical and biosensor methods for on-line monitoring and control of bioprocesses. Topics include the use of expert systems for controlling flow injection analysis systems and hybrid process modeling for bioprocess control. 

Integrated Raman systems can be classified as instruments designed for the research laboratory, for routine analysis, for process control, and for portable, field-deployable applications. Research laboratory instruments offer new and state-of-the-art capabilities in exchange for compromised reliability and frequent need for support from a Raman expert. Research laboratory instruments are extremely adaptable to address unanticipated measurement needs. Routine analysis instruments provide limited flexibility with good reliability. They are operationally simple and contain enough Raman expertise built in for technicians to carry out repetitive assays efficiently and reliably. Process control instruments are typically fiber optic Raman systems that have been hardened to perform in the more challenging environmental conditions typical of a chemical production facility. A process control instrument usually runs continuously in a fully automated mode. There... 

The functionality of expert systems for fault analysis was briefly described in Section 4.1. Expert systems for control are used in chemical processes for which a mathematical model is not available and standard control strategies fail. Such processes are often operated by experienced operators who know how to react in certain situations. Their knowledge is implemented in the knowledge base of an expert system for control. 

SEM s simulate human performance when controlling dynamic systems (Rouse 1980). They match overall human performance very well, or work even better by employing mathematical formulations of systems dynamics. For application purposes computational formulations are often not feasible. SEM s are useful for special purposes such as monitoring, adjusting and predicting outputs in real time. An evaluation of SEM s and expert systems for decision support systems in process control is provided by Zimolong et al. (1987). 

Foxboro developed a self-tuning PID controller that is based on a so-called expert system approach for adjustment of the controller parameters. The on-line tuning of K, Xi, and Xo is based on the closed-loop transient response to a step change in set point. By evaluating the salient characteristics of the response (e.g., the decay ratio, overshoot, and closed-loop period), the controller parameters can be updated without actually finding a new process model. The details of the algorithm, however, are proprietary... 

In the first stages of the development of an Action plan all control options are considered. In the case of lakes, this process is aided by a PC-based expert system , PACGAP, which looks at the physical and chemical characteristics of the lake to determine the most likely option for control. Once further, more detailed information has been collected on the lake s nutrient inputs and other controlling factors, amore complex interactive model can be used (Phytoplankton Response To Environmental CHange, PROTECH-2) to define the efficacy of proposed control options more accurately. This model is able to predict the development of phytoplankton species populations under different nutrient and stratification regimes. 

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