Design And Application Of Fuzzy Control For A Class Of Pure Time Delay System

In industrial production, pure delay often exists in controlled object to varying degrees especially in thermal production, and the object parameters or structures change with the changing of working conditions and environment. This paper, on account of such a pure delay system, focuses on the design and application of fuzzy control in it. Therefore, through a lot of literature research, this article summarizes the existing control methods for this system.Meanwhile, the representative delay system of the circulating fluidized bed boiler is taken as the controlled object, and the fuzzy control is used in the system design, making a more in-depth study on the practical application of fuzzy control. The work carried out in the article is divided into the following aspects:(1) A summary research of the large-delay system control. This article starts from the concept of industrial pure delay system, summarizes the control characteristics and methods, and selects the circulating fluidized bed boiler as the actual object of study, analyses the principles and control methods, which comes to the feasible conclusion of the fuzzy control method on the object in large delay.(2) The fuzzy controller design with the adjustable factor. The article starts from the basic fuzzy controller design. Through designing and simulating the control system of the the circulating fluidized bed boiler of a power plant to the amount of coal-the main steam pressure control loop model, this article analyses and compares the adavantages and disadvantages, and the control characteristics of the basic fuzzy controller and the PID controller. Then it designs the fuzzy controller with the adjustable factor, and analyses the influence of the adjustable factors on the control effect in comparison.(3) A mixed control method of the fuzzy PID based on expert system design. The method fully combines the respective advantages of fuzzy control and PID control, adjusts the output of the two with expert rules, and this controller has a simple design structure. After the experimental analysis, the method has good robustness and improves the control quality to great degree, which has the guiding significance of improvements in engineering controls.(4) The thermal optimization platform system is used to realize the fuzzy algorithm module. Through the user-defined module in the thermal optimization platform system, a fuzzy control algorithm is added, and it is able to change the parameters of fuzzy controller by setting parameters. At the same time,the logical configuration of the closed-loop control comes true by using various functional block. The experimental result shows the superiority of the control effect, and it lays the foundation for the following further practical application.In this paper, fuzzy control in a large delay system is designed and put in application research. At the same time, as a conclusion, it points out the practical problems in industrial production control and the application prospects of fuzzy control, and provides reference for the development and application of fuzzy control in this area.