PID Control Performance Optimization Algorithm Research And Application

In general,the controller will experience performance degradation after long-term operation,resulting in a decline in the production efficiency of industrial processes.Therefore,it is of great significance to evaluate the control performance of the control system,find out the causes of performance degradation,and further take control performance optimization measures to improve the operation of the system.At present,PID controller is still one of the most widely used controllers.Its performance optimization methods include experience-based parameter tuning method,PID parameter self-tuning method,optimization tuning method combined with intelligent algorithm,and model-free data-driven PID controller tuning method.Based on the traditional PID control performance optimization research,this thesis combines CPA technology with PID parameter optimization tuning technology.The specific contents include:(1)An E-FRIT control performance optimization method based on MV index is proposed.This method needs to collect the system operation data to estimate the MV index,and monitor the running system after setting the performance threshold.When the actual MV index is less than the threshold,the E-FRIT method is started to adjust the PID controller parameters to optimize the PID control performance.The advantage of this method is to improve the problem that the traditional FRIT method relies too much on the reference model selection.At the same time,the reference model selection and PID parameter optimization can be carried out at the same time,which improves the variance performance of the closed-loop output and does not produce intense control.(2)A control performance optimization method based on Hurst index is proposed.The traditional performance evaluation results based on the MV index depend on the accuracy of the system delay information.The Hurst index only needs the process data of the system to estimate the control performance index results close to the MV index,which makes up for the deficiency of the MV index.This method first estimates the Hurst index of the system.When the actual Hurst index is less than the expected performance index threshold,the PID controller parameters are optimized to optimize the PID control performance.The PID parameter optimization tuning methods used here include GA optimization method and VRFT method.It is verified that this method can effectively improve the control performance of the system.(3)Based on the above research on control performance evaluation algorithm and PID parameter optimization method,a control performance evaluation and optimization platform based on MATLAB GUI is developed.The platform has two working modes: offline and online.In the offline mode,the industrial data uploaded by the user is analyzed and processed,and the MV index and Hurst index of the system are estimated.When the system control performance does not meet the requirements,the PID control performance optimization function is started.The platform has an online mode,through OPC technology for data transmission,and then realize the online control performance evaluation and optimization function of the water tank level control system.