An investigation of hydraulic actuator performance trade-offs using a generic model

The effect of the variation of parameters of system elements on the overall performance of a generic model of a hydraulic actuation system for a robot is investigated. Specifically, an examination is made of the effects on actuator performance of two issues: intrinsic compliance i.e. the physical compliance within the actuator itself, and independent control of the actuator valve areas (e.g. supply and return areas for hydraulic fluid chamber) versus control of actuator valves with fixed area relationships. Increasing intrinsic compliance in the actuator degrades response to controller commands but improves the ability of the actuator to tolerate disturbances. Independent control of valve areas provides better response to commands and better rejection of disturbances than control with valves that have fixed area relationships. The performance information provided by the model permits behavior-based design of hydraulic actuation systems