Adaptive Continuous Barrier Function Terminal Sliding Mode Control Technique for Disturbed Robotic Manipulator

This paper offers an improved finite time sliding mode controller scheme for a class of robotic manipulators with external disturbances. Since conventional sliding mode controllers have a discontinuous signum function, an important problem called chattering phenomenon can occur in them. The proposed scheme presents a new Lyapunov candidate functional containing an absolute function based on a fractional power of the switching surface such that the designed control law is continuous and smooth. The recommended control technique is designed using the Lyapunov stability theory and satisfies the presence of the sliding mode around designed switching surface in the finite time. The presented method eliminates the chattering problem produced by the switching controller and satisfies high precision action. Besides, the adaptive tuning controllers are designed to approximate the unknown bound of external disturbance. An extension of the proposed control technique based on the barrier function adaptive terminal sliding mode control is also suggested for better performance and robust tracking control of the nonlinear systems with external disturbances. Some simulation and experimental outcomes exhibit the efficacy of the planned technique.

Automated summary

The paper proposes an improved finite time sliding mode controller scheme for robotic manipulators with external disturbances. By introducing a new Lyapunov candidate functional containing an absolute function based on a fractional power of the switching surface, the designed control law is continuous and smooth, eliminating the chattering phenomenon typically associated with conventional sliding mode controllers. The control technique designed using Lyapunov stability theory ensures the presence of sliding mode around the switching surface in finite time, while adaptive tuning controllers are used to approximate unknown bounds of external disturbances, improving precision and robustness in tracking control of nonlinear systems.