PD with Terminal Sliding Mode Control for Trajectory Tracking

Trajectory tracking is one of the most important tasks for the applications of robotic manipulators. In this paper, taking the advantages of the simplicity of the PD control and the fast convergence of terminal sliding mode control (TSMC), a PD-TSMC control law is introduced for tracking control of a 3-DOF robotic manipulator. The PD-TSMC is a model-free feedback control that is different from a traditional TSMC. The kinematics and dynamics are presented first, followed by the proposed controller. Linear and nonlinear trajectories are used to test the control performances of the PD-TSMC. Compared with the existing control laws, simulation results show that the PD-TSMC is superior to the PD-SMC in terms of the tracking performances in the joint level and the space level. In addition, different control parameters are used to evaluate the differences of control performances.