Adaptive control of robotic manipulator with input deadzone and disturbances/uncertainties

Abstract

This work address the problem of trajectory tracking for robotic manipulator while encountering external disturbances and internal uncertainties. Robotic manipulators have been widely used in various industrial and research applications due to their versatility and efficiency. The precise control of these manipulators is essential for their proper functioning. However, due to the presence of uncertainties and disturbances in the system, it is often challenging to achieve accurate control. The proposed controller is capable of handling the uncertainties and disturbances present in the system, making it robust and efficient for practical applications. The controller is designed based on the concept of second-order nonsingular terminal sliding mode control (SNTSMC), which ensures that the system tracks the desired trajectory accurately. The substitution of the sign function with the saturation function effectively reduces the chattering that is caused by the high-frequency switching element in the conventional SMC approach. By utilizing an adaptive technique, uncertainties can be effectively mitigated without relying on any prior knowledge of an upper limit. Moreover, the Lyapunov stability criterion is used to prove the stability of the closed-loop system. The simulation results show the effectiveness of the proposed algorithm in terms of tracking accuracy and robustness.