Modelling and analysis of an asymmetric valve-controlled single-acting cylinder of a pneumatic force control system

This paper describes the transfer function of a pneumatic force control system with a single-acting cylinder. From the experimental results of an asymmetric servovalve, the typical three coefficients of now gain, now-pressure coefficient and pressure gain are obtained. The linear mathematical models are introduced, then the dynamic models are derived and simplified to be a transfer function of the third order under three simplified conditions. The relations between mechanical the parameters and gains, frequency bandwidth, steady-state error of the system are also discussed. Experimental results of frequency responses of the closed-loop pressure control system are presented.