Research And Realization On The Control Algorithm Of Intelligent Electropneumatic Valve Positioner

Valve positioner is widely used in industrial field. The algorithm is very important to the control quality. A wide varity of positioners such as mechanical, electronic, bus and intelligent types have been developed. The bus and intelligent positioners have the advantages of no overshoot, low failure rate, high stability, which occupy most of the domestic market. Due to the high failure rate, domestic positioners have poor market share. Algorithm is the key problem. Therefore, the algorithm research for intelligent electric valve positioner is very necessary.An intelligent control algorithm suitable for electropneumatic positioner combines the fuzzy adaptive PID and Smith predictor is proposed. The algorithm has good result for the uncertainty model by adjusting the control parameters online.The following achievements have been made:First, the operating characteristics of the electropneumatic valve positioner and control algorithm is studied and the control strategy is determined. Fuzzy adaptive PID control of Smith predictor was used in the system. Control rules are established based on the performance of positioner. The positioning speed of and precision are improved.Second, simulation model based on pneumatic actuators is established in MATLAB/SIMULINK and Fuzzy adaptive PID control of Smith predictor algorithm is simulated.Third, control algorithm was tested by joining the disturbance, delay and other factors to verify the robustness of stability follow performance and other properties. Fuzzy adaptive PID control of Smith predictor has obvious advantages comparing with other control algorithms.Compared with the conventional positioning of the control algorithms, the algorithm proposed by the author has the advantages of simple, fast response, no overshoot, good robustness, wide application and anti-interference ability, etc., which has a good prospect.