Compensation in pneumatically actuated servomechanisms

Abstract

This paper describes the features of a pneumatically actuated servomechanism which has been designed for the point-to-point positioning of payloads. The servomechanism utilises low cost computer control and interface electronics to facilitate software compensations for system time delays and non-linearities. The compensation algorithms hve been designed and developed with reference to a linearised model of pneumatic servodrives, which allows for variation in transfer function with load position. Application of these algorithms has allowed a substantial improvement in static performance and dynamic characteristics to be realised for drives incorporating various forms of pneumatic servo valves, pneumatic actuators and load systems. This offers a significant opportunity for commercial exploitation of the pneumatic servodrive. The paper describes the method by which compensation is achieved and references experimental data, which have been obtained by using a standardised evaluation procedure.