Abstract
Servo pneumatic positioning control systems have the advantages of high response, easy maintenances and cleanliness, but the positioning accuracy is restricted by systems' non-linearity, such as friction force. In this study, a high precision pneumatic-piezoelectrical hybrid positioning control system is developed. Such a system contains a servo-pneumatic cylinder and a piezoelectric actuator. The servo pneumatic cylinder serves to coarse positioning with high speed and large stroke, and the piezoelectric actuator positions in fine stroke to compensate the influence of non-linearity to achieve large stroke, high response and high positioning accuracy. The overall control system becomes a complex dual-input single-output (DISO) control system. The test results show that the positioning accuracy for the large stroke of 180 mm can achieve 1μm.
