Sliding mode switching control scheme for an uncertain robotic manipulator system under arbitrary switchings

The sliding mode switching control problem is considered for an uncertain robotic manipulator system in this paper. The presented robust switching control method with disturbance observer under arbitrary switchings is employed to enhance the robustness and overcome the system disturbance, which can guarantee the resulting closed-loop switching control system is asymptotically Lyapunov stable and can achieve good position tracking error performance of robotic manipulators. Finally, a numerical example on the switching robotic manipulators is provided to demonstrate the effectiveness of the presented control algorithms.

I. Introduction

In the past several decades, the robust control of switched nonlinear systems has attracted numerous research interests. Efforts have been devoted from the perspective of robust and anti - interference control for various structures of switched nonlinear systems. It is well known that the switching control scheme of complex nonlinear systems has superior robustness to obtain good tracking performance[I-12]. The switching controller design and stability analysis attract a lot of attention under periodically switching, event-driven switching, arbitrary switching and under some designed switching signals. The aim is to present the robust switching control algorithm for proving system stability and obtaining the better tracking control performance. As we know, switching control method has a large number of practical applications in the control area of power plant systems, computer networks, chemical control system, railroad mechanical systems, automatic highway systems, industrial process control systems and many other control fields [10]–[18]. However, due to the limitation of traditional switching theory, robotic manipulator system as complex nonlinear systems is hard to handle the tracking performance, which can be modeled as switching systems.