Research On Electric Pro-Portional Pressure Reg-Ulating Valve System Based On Fuzzy Self-Tuning PID Control

As the core control component of pneumatic technology,the electric proportional pressure regulating valve has the characteristics of high control accuracy,good reliability,fast response speed and can realize the conversion between electrical signal and pneumatic signal.It is wide l y used in the field of air pressure control.At present,the research and production of high-end electric proportional pressure regulating valve are mainly controlled by a few large foreign companies,and the import price is expensive.This thesis aims to develop a low-cost and highperformance electric proportional pressure regulating valve,and research on the electric proportional pressure regulating valve control system based on fuzzy self-tuning PID control algorithm.Firstly,this thesis briefly introduces the commonly used air pressure control strategy,and selects the control method suitable for this paper,namely the fuzzy self-tuning PID control algorithm.This strategy can effectively solve the shortcomings of the response lag and nonlinearity of the pneumatic system,so that the system has a good control effect on the air pressure.At the same time,the structure and working principle of the electric proportional pressure regulating valve are introduced.Based on this,design the functional modules of the system.Secondly,the hardware and software of the electrical proportional regulator control system and the fuzzy PID controller are designed separately.The control core of the hardware part is composed of STC8A8K64S4A12 microcontroller and its minimum system.At the same time,according to the needs of system,other peripheral circuit modules are designed,such as highspeed switching valve drive circuit,pressure acquisition and AD conversion circuit.The design of the fuzzy PID controller is to complete the design of the fuzzy controller,PID controller and their combination method.The software part is composed of host computer and slave computer.The slave computer completes the design of the single-chip microcomputer control system through modular programming,and the host computer is used to realize the display and storage of pressure data and configuration of the setting values and PID parameters through Labview software programming.Finally,the performance of the designed electrical proportional regulator control system was tested.To build an experimental platform,first complete the calibration of the pressure sensor,as well as the determination of the high-speed switching valve drive frequency and the system sampling frequency.Then the traditional PID control strategy is compared with the fuzzy selftuning PID control strategy.The experiment shows that the latter has higher control accuracy.Finally,through the experimental test of step response and constant pressure regulation of the pressure regulating valve,it is verified that the electrical proportional pressure regulating valve based on fuzzy self-tuning PID control has good working performance.