This paper analyzes the number of operations and parameters of general fuzzy logic control algorithms. And limitations of loop controllers to implement the fuzzy logic control are investigated in terms of computation ...
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This paper analyzes the number of operations and parameters of general fuzzy logic control algorithms. And limitations of loop controllers to implement the fuzzy logic control are investigated in terms of computation time and required memory. Using analysis of general fuzzy logic control algorithms, it is shown that general fuzzy logic control algorithms are not suitable for loop controllers. A simplified fuzzy logic control for loop controllers is presented using a fixed control table with mapping parameters. This simplified fuzzy logic control is shown to be suitable for a loop controller with regard to the computation time and the required memory. For easy programming of the simplified fuzzy logic control, a fuzzy logic control block is suggested as a specific block for general graphical block diagram editors. Experiments show that the simplified fuzzy logic control overcomes the limitations of loop controllers and provides good performance. (C) 2000 Elsevier Science B.V. All rights reserved.
Commercially, the Czochralski process is the most commonly applied method for production of monocrystalline silicon for semiconductor and solar cell applications. The process has traditionally been controlled using ne...
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It is sometimes necessary that a process plant operates over a wide range while satisfying desired performance and stipulated constraints. This paper proposes a method based on computing a mean (nominal) plant, uncert...
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The BodeRC paper-path setup represents the paper transport path of a printer. It consists of a series of ve pinches that transport a sheet of A4 size paper through the path. In this assignment a model and a control sy...
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The BodeRC paper-path setup represents the paper transport path of a printer. It consists of a series of ve pinches that transport a sheet of A4 size paper through the path. In this assignment a model and a control system of the paper-path have been designed such that the design trajectory as described in (Visser and Broenink, 2006) can be evaluated. The designed control system is capable of centralised control as well as distributed control. To get a structured approach in the design, the trajectory described by Broenink and Hilderink (2001) was followed. The rst step in the trajectory is the design of a model of the physical system, the paper-path. This model was designed, veried with simulations and validated against experiment results on the setup. The results proved the correct functioning of the model. From the results it became clear that the paper detectors on the setup were not precise enough; A small alteration solved this problem. Next, a control system has been designed. This system is capable of controlling the velocity of a sheet of paper throughout the entire paper-path. The control system relies on the presence of loop controllers for the pinches, which have been developed. The complete control system was evaluated, rst in simulation together with the model then as embedded control system together with the paper-path setup. The resulting error is within the measurement resolution. Finally, a distribution of the control system was designed. The distributed control system has been veried using simulations. The error proved to stay within the measurement resolution. Because the absence of software that handles the communication between nodes, the distributed control system could not be tested in practise.
With the advent of fieldbus, the manner in which process control devices are engineered, installed, and maintained is expected to dramatically change. To illustrate how fieldbus' power and flexibility can be used,...
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With the advent of fieldbus, the manner in which process control devices are engineered, installed, and maintained is expected to dramatically change. To illustrate how fieldbus' power and flexibility can be used, several wastewater examples are considered. Also, several different technologies, including fieldbus, are discussed.
Many production engineers, and even process control engineers, do not realize that there is a way to evaluate the operation of individual process control loops right from the control room. The open-loop response test,...
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Many production engineers, and even process control engineers, do not realize that there is a way to evaluate the operation of individual process control loops right from the control room. The open-loop response test, which is a part of the a three-step evaluation procedure, enables plant or refinery personnel to define the process by determining the process time constant, process gain, and process deadtime. Using these values, new controller settings can be calculated and applied. Resulting improvements in loop performance lead to better overall control to the process and enhanced productivity.
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