Dynamic analysis of pneumatic actuators

The paper deals with the dynamic analysis of double acting actuators, both linear and rotary ones. Two different formulations to model a pneumatic circuit, composed of an actuator and a digital valve, are presented. In the first one an air thermodynamic transformation is assumed and the simulation is carried out in the MATLAB-Simulink environment, while in the second one also the energy equation is introduced, so that the thermic exchange between the chambers and the external ambient is considered. Furthermore models of actuators, both linear and rotary, using the bondgraph method are presented; the energy and continuity equations are implement by using two C-fields. Finally simulations results, obtained in the two different environments, are compared and discussed.