Lumped Parameter Mass Flow Rate and Pressure Control Characteristics Model for High-Speed Pneumatic PWM on/off Valve  

作　　者：向忠 胡旭东 刘昊 汝晶炜 

机构地区：[1]Faculty of Mechanical Engineering & Automation,Zhejiang Sci-Tech University [2]State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University

出　　处：《Journal of Donghua University(English Edition)》2014年第3期293-303,共11页东华大学学报（英文版）

基　　金：National Natural Science Foundation of China(No.51205362);Zhejiang Provincial National Science Foundation of China(No.LQ12E05017)

摘　　要：Aiming at solving the problem of strong coupling characteristic of the key parameters of high-speed pneumatic pulse width modulation( PWM) on / off valve, a general lumped parameter mathematical model based on the valves time periods was well developed. With this model,the mass flow rate and dynamic pressure characteristics of constant volumes controlled by high-speed pneumatic PWM on /off valves was well described. A variable flow rate coefficient model was proposed to substitute for the constant one used in most of the prior works to investigate PWM on /off valves' dynamical pressure response, and a formula for disclosing the inherent relationship among the PWM command signal,static mass flow rate,and sonic conductance of the valve was newly derived.Finally,an extensive set of analytical experimental comparisons were implemented to verify the validity of the proposed mathematica model. With the proposed model, PWM on /off valves' characteristics,such as mass flow rate,step pressure response of the valve control system,mean pressure and ripple amplitude,not only in the linear range,but also in the nonlinear range can be wel predicted; Good agreement between measured and calculated results was obtained,which proved that the model is helpful for designing a control strategy in a closed loop control system.Aiming at solving the problem of strong coupling characteristic of the key parameters of high-speed pneumatic pulse width modulation（ PWM） on / off valve, a general lumped parameter mathematical model based on the valves time periods was well developed. With this model,the mass flow rate and dynamic pressure characteristics of constant volumes controlled by high-speed pneumatic PWM on /off valves was well described. A variable flow rate coefficient model was proposed to substitute for the constant one used in most of the prior works to investigate PWM on /off valves＇ dynamical pressure response, and a formula for disclosing the inherent relationship among the PWM command signal,static mass flow rate,and sonic conductance of the valve was newly derived.Finally,an extensive set of analytical experimental comparisons were implemented to verify the validity of the proposed mathematica model. With the proposed model, PWM on /off valves＇ characteristics,such as mass flow rate,step pressure response of the valve control system,mean pressure and ripple amplitude,not only in the linear range,but also in the nonlinear range can be wel predicted; Good agreement between measured and calculated results was obtained,which proved that the model is helpful for designing a control strategy in a closed loop control system.

关 键 词：lumped parameter model pneumatic on/off valve pulse width modulation(PWM) mass flow rate pressure characteristic 

分 类 号：TH137.52[机械工程—机械制造及自动化]