Study Of Intelligent Hydraulic Positioner Control Algorithm

Hydraulic control valve is an important implement in industrial process control. Valve-Positioner is the major accessories of control valve, which can improve the performance of valve apparently, such as flexibility, speed and the precision of valve. Since Valve-Positioner is a system, the key work of this text lies in the control algorithm of the Intelligent Valve-Positioner for Hydraulic Actuators.Firstly, text expounds the principle, structure, advantage and function in industrial process control of Valve-Positioner, and explains intelligent Valve-Positioner's parameters and other equipments'Principle and transfer function.Secondly, text establishes the dynamic model of hydraulic control valve, i.e. the mathematics model of object and deduces the transfer function of open loop. Then, this text puts forward a new algorithm—fuzzy-PI control algorithm. And it expounds how to set up a fuzzy controller. This chapter is the core of this text.Then, we simulated the Fuzzy-PI controlled system and PID controlled system with Matlab Simulink software separately. By contrast their output curve, we can discover that the performance of the system with Fuzzy-PI controller is better than the system with PID controller notablely. Simultaneously it also confirmed the Fuzzy-PI compound control is effective and successful. Base on the simulation of the two algorithms, we sum up and summarize the virtue and shortcoming of fuzzy control and PI control. Since fuzzy control is complementary with PI control in certain aspect, therefore, the combination of fuzzy control and PI control is necessary to development. Fuzzy-PI control has fuzzy control's robustness, distinct structure and the PI control's high static precision and quickly dynamic response.Finally, we generalized this texts'content and fruits, prognosticated the further development of intelligent Valve-Positioner, offered some advice for further work.