COMPARING DIFFERENT CONTROLLERS OF ELECTROPNEUMATIC POSITION SERVO

Abstract

The natural frequency and damping are especially low in most applications of pneumatic position servos. However the steady state and dynamic specifications are demanding, because pneumatic position servos have to compete with hydraulic and electric servo systems. The only way to increase the effective natural frequency and damping is to use a controller which can move the poles of the system so that really remarkable improvements can be achieved. The state controller is the most often used controller in pneumatic position and also velocity servos. The state controller is an effective controller in a position servo system. However in the practical realization of the state controller there are some drawbacks including low robustness and the requirement of a high resolution position transducer. In this paper some alternative controllers are studied and compared with the state controller.