Parameter Identification And Fuzzy PID Control Strategy Research Of Electro-hydraulic Proportional Valve Loading System

This paper builds the most appropriate loading system: electro-hydraulic proportionalvalve loading system (respectively using proportional overflow valve and proportionalthrottle valve) for pump controlled motor and valve-controlled motor system onelectro-hydraulic proportional pressure-flow control test rig in Chang’an university. Thispaper makes detailed elaboration on composition, working principle of loading system, andmakes detailed introduction for the main components proportional relief valve andproportional throttle valve.Electro-hydraulic proportional valve loading system implement loading for motorthrough changing the input signalsto proportion valve electrical, so the key we study is to findout the relationship between the proportional valve input signals and the output shaft torque ofthe motor. The paper makes modeling analysis for electro-hydraulic proportional valveloading system components, after integration, respectively obtain the transfer function ofelectro-hydraulic proportional overflow valve loading system and electro-hydraulicproportional throttle valve loading system. Getting proportional valve input signals and thetorque of the motor output shaft of two system, using identification toolbox of the MATLABmakes parameter identification for them, so as to get the more accurate transfer function ofthe electro-hydraulic proportional overflow valve loading system and electro-hydraulicproportional throttle valve loading system.The paper looks transfer function of electro-hydraulic proportional overflow valve andproportional throttle valve loading systemas a controlled object,designs the PID controller forthem. And we completeinitial setting work of the three PID controller parameters KP, KI, andKD. But finds the control effect is still not satisfactory after analysis. So we designFuzzy PIDcontroller which has ability of PID parameters self-tuning. Make modeling and simulationforthe two kinds ofelectro-hydraulic proportional valve loading fuzzy PID control system. Bycomparing the simulation results, it can be seen that the fuzzy PID control can greatlyeliminate the overshoot, decrease the oscillation and guarantee system has good followingperformance. Fuzzy PID controller which has ability of PID parameters self-tuning can bebetter adjusted to the electro-hydraulic proportional valve loading system, and improve thecontrol quality of electro-hydraulic proportional valve loading system.