A Unified Approach to Variable Structure Control of Robot Manipulators

A general target model is proposed in the task space to represent motion trajectory, interaction force trajectory, and second-order function relating the motion errors and the interaction force errors. Using variable structure model reaching control (VSMRC) strategy, the model is achieved in the sliding mode with robust performance. Prescribed. quality is also guaranteed in the reaching transient. By choosing a suitable model for the application, robust motion control, impedance control, hybrid position/force control, or constrained motion control are achieved respectively. Simulation result and experimental study illustrate the proposed method.