Cartesian trajectory control of a flexible manipulator using sliding mode

Abstract

A sliding mode control algorithm is presented for Cartesian trajectory control of a three-axis flexible manipulator by using the theory of variable structure systems. The manipulator has two rigid links and the third link is elastic. A parameterization of the Cartesian coordinates of a point close to the end-effector position is suggested. Using these coordinates as output variables, a discontinuous output control law is derived based on the variable structure theory for tracking reference Cartesian trajectories. To regulate the end point to a fixed position, a linear stabilizer is designed to damp the elastic vibration. Simulation results are presented to show the robustness of the proposed controller in spite of the parameter uncertainty in the arm dynamic model.