Decoupled Adaptive Backstepping Sliding Mode Control of Underactuated Mechanical Systems

Abstract

In this paper, a combination of sliding mode control and adaptive backstepping control with a decoupling algorithm is considered for controlling 2 degrees of freedom underactuated mechanical systems subject to parametric uncertainties and external disturbances. The stability of the system is assured by the design steps of the proposed decoupled adaptive backstepping sliding mode control which are based on the Lyapunov theorem. The effectiveness of the proposed decoupled adaptive backstepping sliding mode control method is compared against a decoupled sliding mode controller by testing on a real-life inverted pendulum on a cart system which is a classical testbed for underactuated mechanical systems. The experimental outcomes justify the proposed decoupled adaptive backstepping sliding mode controller provides a more satisfying performance compared to the conventional decoupled sliding mode controller. Besides the proposed method is able to handle parametric uncertainties contrarily to the decoupled sliding mode control.