Comparative implementation studies of the minimal controller synthesis algorithm on an electrohydraulic actuator plant

Abstract

Electrohydraulic servosystems have large extent of model uncertainties and generally difficult to control. The current paper studies the application of the direct adaptive minimal controller synthesis (MCS) algorithm to an electrohydraulic positioning system. Comparative implementation studies are presented of a typical servohydraulic positioning system, as used in aerospace applications. The performance of the MCS controller is evaluated through experimental and analytical studies. In order to investigate the robustness of the MCS control, the system is operated away from nominal working condition (by changing the supply pressure and/or accumulators settings) and the performances of both the MCS control and the proportional plus derivative feedback (P + DFB) controller were compared. The results show that MCS is fairly insensitive to parameter variations, unmodelled dynamics and external disturbances, yielding much better response characteristics, compared with those of a conventional P + DFB controller.