Research on Global Nonsingular Fast Terminal Sliding Mode Control Strategy of Ball Screw Feed System Based on Improved Double Power Reaching Law

Aiming at the problems of low trajectory tracking accuracy, serious chattering and poor robust performance of ball screw feed systems in traditional sliding mode control (SMC), in this paper, a global nonsingular fast terminal sliding mode control (GNFTSMC) strategy based on improved double power reaching law (DPRL) and extended state observer (ESO) is proposed. Firstly, the system state variable is introduced into the power term of DPRL, so that the improved DPRL has the characteristics of variable speed reaching, which solves the contradiction between the reaching rate and the sliding mode chattering. Secondly, ESO is designed to observe the state of the system and match the external disturbance to improve the anti-interference performance of the system. Finally, GNFTSMC is designed for the ball screw feed system, and the global sliding mode factor is introduced to improve the trajectory tracking accuracy of the system. The results show that the proposed control strategy can effectively improve the tracking accuracy and anti-interference performance of the system.