Self-tuning Fuzzy Control Methods Research For Batch Reactor Based On Cat Swarm Optimization

The batch reactor as a chemical reaction apparatus has been widely used in a batch or semi-batch of the productive process of the petroleum, chemical engineering, pharmacy and food. However, because the temperature control process of the batch reactor has many characteristics of the nonlinearity, large inertia, strong hysteresis and model structure uncertainty, the use of the traditional control method is difficult to achieve the good control effect. with the batch reactor as an object and temperature control as a target, on the basis of the in-depth study of the its dynamic characteristics, for the lack of the conventionally fuzzy control, two self-tuning fuzzy control methods based on cat swarm optimization are proposed in this paper, and the applications of the methods in the actual production of Ethyl acetate are discussed.The main contents are as follows:(1) As to the problem that the parameter and fuzzy rules for the conventional fuzzy controller cannot be adjusted online at the time of the system operation, the rule self-tuning fuzzy control method based on cat swarm optimization is proposed. For the controller, the function of fuzzy rules with a weighting factor was introduced to initialize fuzzy reasoning. Then, cat swarm optimization was used to optimize relative parameters of the controller, such as weighting factor and quantification factors, based on the performance evaluation function of the system, so as to obtain a group of the relatively optimal fuzzy control parameters to make the tracing value reach the relatively ideal control effects. The simulation results indicate that the rule self-tuning fuzzy controller can promptly adapt the changes of the dynamic characteristics of the object and the control effect is good by comparing with the traditionally fuzzy controller.(2) As to the question that the fuzzy universes for the conventional fuzzy controller cannot be adjusted at the time of the system operation, the variable universe fuzzy control method based on cat swarm optimization is proposed. By respectively introducing the corresponding contraction-expansion factors with the function form in the input and output fuzzy universes of the controller, cat swarm optimization was used to optimize the relevant parameters of the contraction-expansion factor functions to achieve the intelligence optimization of the contraction-expansion factors. Based on the system performance test function as an evaluation index, the contradiction between the universe adjustment and control accuracy of the fuzzy controller will be effectively solved to achieve the on-line self-adjustment of the universe. The simulation results indicate that the variable universe fuzzy control method based on cat swarm optimization has the features of high precision adjustment, short transient time and hard real-time.(3) In order to verify the feasibility of the control algorithm, the esterification reaction production line of ethyl acetate is build. The production line takes PROFIBUS-DP field bus as a bridge, with S7-300 PLC as the control master station, S7-200 PLC as the slave station, master-slave compound control is conducted on the whole production line, and real-time monitoring is carried out on the whole system through the upper computer. Among them, this paper focuses on the research of temperature control of reactor in the production line, and based on STEP 7,data acquisition module, filtration module, fuzzy control module and other relevant control procedures of reactor are written. Based on King View 6.53, the configuration and monitoring screens of the host computer are designed to monitor the temperature of the reactor. Finally, to debug and operate in the actual control system, the actual control results indicate that the self-tuning fuzzy control methods designed in this paper have such features as the quick reaction rate, small steady-state error and strong robustness, which may have higher practical values.