Trajectory tracking of robot manipulator with adaptive super-twisting non-singular terminal sliding mode controller

Trajectory tracking is a fundamental challenge for robot manipulators, hindered by system dynamics, uncertainties, and disturbances. This paper proposes an adaptive super-twisting non-singular terminal sliding mode control (ASTNTSMC) method to enhance tracking robustness and accuracy. A dynamic model for 6-DoF robot manipulators is established, integrating model errors and disturbances to analyze system dynamics. System uncertainties are lumped into a unified function, and an adaptive law adjusts the joint torque based on tracking errors. The super-twisting algorithm is incorporated into sliding mode control to suppress chattering, with stability verified via Lyapunov function analysis. Simulation and experimental results demonstrate that ASTNTSMC outperforms traditional sliding mode control (TSMC) and continuous terminal sliding mode control (CTSMC), achieving a root-mean-square tracking error reduction of up to 69.78% in joint space and an improvement of 84.38% in position accuracy in Cartesian space.