LAUSR

Electrohydraulic system (EHS) is extensively utilized in experimental testing field for exerting forces on specimen, and in many occasions, force tracking of EHS is confronted with external motion disturbance, which seriously deteriorates the force tracking performance. To address this problem, a real-time nonlinear adaptive force control strategy is developed in this paper. On the basis of the established nonlinear model for EHS, the proposed nonlinear adaptive force controller is obtained by a recursive backstepping method, where both servo-valve nonlinearity and parametric uncertainties of general electrohydraulic systems are accounted for during the controller design procedure. The first advantage for the proposed controller lies in the fact that the actuator’s vibration disturbance information is utilized to serve the purpose of accurate force tracking. Besides, parametric uncertainties are effectively handled by the developed online adaptive updating law to achieve a higher force replication performance. Moreover, rigorous Lyapunov stability of the proposed controller is guaranteed. Finally, comparative experiments are implemented on a uniaxial EHS through xPC/Target rapid prototyping technique, and the relevant results validate the feasibility of the developed controller.