Research On Hydraulic System Controller Based On Electro-hydraulic Servo Valve

Electro-hydraulic servo system(EHSS)is widely used in industrial field since of its high precision,high power/mass ratio and good stability.With the development of industrial automation and the proposal of Industrial 4.0,higher requirements are put forward for the performance and application environment.As the control core of EHSS,traditional electro-hydraulic servo controller can not meet the control requirements.Researching and developing integrated,intelligent and digital controller with high stability is the trend of EHSS.This paper focus on the development of electro-hydraulic servo controller.According to the needs of research topics,this paper designs an electro-hydraulic servo controller based on ARM,which uses STM32F407ZGT6 as the core,and communicates with the host computer via the CAN bus,it can query and modify related parameters online.The hardware part includes SWD download circuit,U/I conversion circuit,I/U conversion circuit,constant current source circuit,power conversion circuit,signal recognition circuit,CAN communication circuit and memory circuit is designed and tuned.The software part includes initialization program,A/D conversion and filtering algorithm program,control algorithm program,communication program,etc is debugged.Aiming at the influence of interference in the industrial field,an improved threshold wavelet de-noising algorithm is designed in the software to filter out noise signals of high frequency.The simulation results in Matlab prove that the wavelet de-noising algorithm is effective.In the control algorithm part,the classical PID control theory and fuzzy control theory are combined to design the fuzzy self-tuning PID control algorithm.The simulation model of the EHSS is build in Simulink,the results show that the fuzzy self-tuning PID control algorithm is better than the classical PID control algorithm in EHSS.The fuzzy self-tuning PID control algorithm had better adaptability and control effect,which evidently reduces the overshoot and adjustment time of the system,and the response speed of the system is faster.Finally,the test system is established.The test results show that the EHSS has good stability,fast response and high control precision,which meets the design requirements of the system.