Integrated Model-based Backstepping Control for an Electro-Hydraulic System

摘要

The demand to obtain an accurate and high efficiency hydraulic actuator has been increasing in heavy industries. However, the existence of uncertain, nonlinear, and unknown terms in system dynamics limits the performance of the hydraulic actuator significantly. To deal with these problems, this paper proposes an advanced control approach, named the integrated model-based backstepping (IBS) controller, for position-tracking control of a pump-controlled Electro Hydraulic System (PEHS). First, a mathematical model of the studied system is fully derived in which the structure of the system elements is clearly presented. Second, to realize the control performance in both transient and steady-state responses, and to simplify the design procedure, an advanced backstepping technique is then employed to compensate for the nonlinearities and unknown terms, while the uncertainties are well treated by a novel identification method based on the obtained model. Third, the stability of the closed-loop system is theoretically maintained using Lyapunov functions. Finally, the effectiveness and feasibility of the proposed method are confirmed by comparing with a tuned proportional-integral-derivative (PID) controller and a direct backstepping (DBS) controller in the real-time tracking control of the PEHS to follow various trajectories under different testing conditions.