Performance of a pneumatic force controlling servosystem: Influence of valves conductance
The paper presents the study addressed to evaluate the performance of a pneumatic force controlling servosystem. In particular, the servoactuator operating range, whereby the desired force can be controlled in steady-state working condition with speed disturbance, is analyzed. The servosystem is described with continuity flow-rate and rod equilibrium equations for the cylinder and the equation of air mass flow-rate through the valves. The parameters considered during the study are the force exerted by the cylinder, the speed of the rod, the sizes of the cylinder and valves, the pressure values of the air inside the chambers of the actuator, the coefficient of the polytropic transformation of the air. The methodology of analysis considers a dimensionless parameter in order to obtain general results which could be applied to any specific actual case. Furthermore, an application of the servosystem with digital modulated valves is presented and its nonlinear model in Matlab/Simulink environment is described. In conclusion the servosystem performance as obtained through nonlinear simulation is investigated on the basis of the non-dimensional design diagrams.
force control servosystem design methodology pneumatic servosystem pneumatic valve conductance pnm/pwm modulation