Four DOF manipulator control using terminal nonsingular sliding mode

This paper presents a new terminal non-singular sliding mode (NSTS) controller proposed for a second-order four-degree-of-freedom (4-DOF) robotic manipulator. This system is designed with a new exponent for the terminal sliding surface. The latter is designed to solve the singularity problem in the first derivative of the sliding surface. Such a problem is associated with the conventional linear hyperplane terminal sliding mode control. Error convergence time from any initial state is guaranteed to be a finite time. Lyapunov stability analysis and Simulation results are presented in this paper. Furthermore, a comparison is implemented with the conventional linear sliding mode in the simulation part. The obtained results prove improved performance in trajectory tracking.