Model reference robust adaptive control with zero-state transient improvement: Application to force control of a hydraulic actuator

This paper deals with direct adaptive force control with large disturbances, neglected dynamics, and unknown system parameters. First, we investigate a modification of a Model Reference Robust Adaptive Control (MRRAC) scheme for zero-state transient performance improvement. This modification is based on an augmentation of a MRRAC law with an auxiliary control component. We point out the auxiliary control design can be treated as a H-infinity - optimization problem for which the solving algorithm initiated by Glover and Mac Farlane 1989 can be applied. The performance of the modified MRRAC scheme is then evaluated trough simulation results related to force control of a hydraulic actuator. These results lead us to propose an additional modification of the control law to improve the damping of the transient oscillations. Copyright (C) 1998 IFAC.