Design of a global sliding mode controller for robot manipulators with robust tracking capability

A scheme for a global sliding mode controller (GSMC) is proposed to achieve robust tracking control of robot manipulators. The proposed scheme provides much flexibility in the design of sliding mode control of robot manipulators by assigning a specific function(s) according to the characteristics and specification(s) of the controller structure. The existence of global sliding is verified according to Lyapunov's second method. The redesign of the variable-structure model-following control (VSMFC) and integral variable-structure control (IVSC) is presented in a scheme proposed to demonstrate its flexibility and superiority with robust tracking control of a two-link revolute joint manipulator subjected to a variable payload. To alleviate chatter induced by finite switching, we propose a novel nonlinear filtering scheme. Simulations were performed to illustrate the efficiency of the proposed method.