Design of pid robot controllers via vss approach

摘要

Sliding mode control could be applied to the control of the point-to-point displacements of robot manipulators, with sliding manifolds defined by simple nonlienar function of position errors. This results in smooth displacements without requiring preliminary velocity programming. The control law consists of nonlinear functions of the position errors and velocities, multiplied by decoupled sign functions of the switching variables. Substituting sat functions with limits equal to the bounds on the control actions, and introducing proper integral actions for good positioning accuracy, leads to Variable Structure Control Systems equivalent to nonlinear PID-like controllers. Performance of this control system is appriments on an industrial robot with revolute joints.