Optimal System Design of SISO-Servopneumatic Positioning Drives

Servopneumatic actuators are very attractive for automated handling tasks or robot operations. They have many advantages such as high speed, high robustness in rough manufacturing environment or high power-to-weight ratio. The considered actuator system is a standard configuration in pneumatics consisting of a double acting pneumatic cylinder controlled by a proportional directional control valve. For the set-up a detailed mathematical model is derived. In order to guarantee an accurate tracking behaviour, a model-based nonlinear controller is presented. Model based approaches for the control design have several advantages. Tuning of the controller can be reached in a systematic way even in the case of a large variety of different configurations. But not only the control design itself can be treated. The model offers the possibility to optimize the size of components for demanded automation tasks. In most cases, this is solved based on steady state assumptions. In this contribution, a method for a design procedure for the pneumatic actuator system based on the dynamic equation is presented. With the representation of the system, an optimization procedure for the components is introduced. The optimization criteria consist of the minimization of the air consumption and investment costs.