Adaptive, high bandwidth control of a hydraulic actuator

Hydraulic servovalve controlled systems contain many time-varying dynamic characteristics that are difficult to model. Controllers for such systems must either adapt to these changing parameters or be robust enough to handle the parameter variations. In order to achieve the highest possible bandwidth, an adaptive controller is developed for the system that uses full-state feedback for simultaneous parameter identification and tracking control. This controller takes into account the hydraulic fluid compressibility with an on-line identification scheme. Experimental results demonstrate a four fold improvement in bandwidth as compared to a conventional fixed gain proportional controller.