Computer Controlled Pneumatic Servo Drives

Abstract

This paper describes how microprocessor-based controls can be used to produce low cost pneumatic servo drives which could find wide application in manufacturing industries. The approach incorporates digital compensation for system non-linearities so that, when positioning loads in a ‘point to point’ mode, it is possible to achieve a significant improvement in both the static and dynamic performance of the drive. For the compensation algorithms implemented a theoretical foundation is presented based on a linearized model of pneumatic drives. The paper also describes how microprocessor-based hardware and software have been constructed to evaluate performance criteria. This test facility has allowed the software implementation of the compensation algorithms to be refined so that satisfactory performance can be achieved with both translational and rotational drives utilizing various forms of transmission. The test facility has also allowed various control system elements to be evaluated so that pneumatic drives suitable for industrial application, can be specified.