Finite-Time Convergent Control of Electrohydraulic Velocity Servo System Under Uncertain Parameter and External Load

Abstract

The disturbances suppression is one common control problem in electrohydraulic systems (EHSs) since both unknown external load and hydraulic parametric uncertainty often obviously degrade the tracking performance and bias the load pressure of EHS. In this paper, a finite-time convergent controller (FTCC) is tried to use in EHS to address this problem. Different from the asymptotic convergent controller, this FTCC not only improve the dynamic and steady tracking performance of the velocity servo system but also guarantee the system state error convergent to zero in a finite time. According to the finite-time stable principle, the FTCC is derived by backstepping and fractional-type Lyapunov techniques. The effectiveness of the proposed controller is verified by comparative simulation and experimental results with the other traditional and advanced controllers.