Parameter Identification and Hysteresis Optimization of Pneumatic Proportional Valve
As the core component of pneumatic proportional control system,pilot-operated pneumatic proportional valve has hysteresis characteristics in time response,which affects the control response speed of the system.Aiming at the problem,based on its internal structure and working principle,the dynamic characteristics of pilot-operated control stage,main valve spool and the gas flow process in the valve are modeled and analyzed,and the equivalent spring stiffness and Stribeck friction coefficient in the valve are identified by genetic algorithm.AMESim is used to simulate and analyze the pilot-operated pneumatic proportional valve,and the influence of the main parameters such as the upper chamber volume,equivalent spring stiffness and the entrapment area of the pilot-operated inlet channel on the response hysteresis and control accuracy is obtained.Aiming at minimum hysteresis,the optimal parameters are determined by quadratic programming algorithm.The results show that the dead-time is reduced from 0.041 s to 0.031 s,and the time to steady-state is shortened by 20.79％ after the sequential quadratic planning design.By optimizing the proportional valves of different calibers,the response hysteresis is reduced by about 20％ under the premise of ensuring the control accuracy.The research results can provide a theoretical basis for the parameter design of pilot-operated pneumatic proportional valve.
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维普
