Sliding Mode Control for Flexible Joint Space Robot Via Nonlinear Integration

Aiming at solving the problems of trajectory tracking and joint flexible vibration of base attitude-controlled flexible jointed space robots under external disturbances, a novel control method based on nonlinear integral sliding mode is proposed. Firstly, the dynamic model of flexible joint space robot with floating base attitude controlled is established by using Lagrange method, and the system model is approximately decomposed into two subsystems, which are fast and slow, according to singular perturbation theory. For the slow subsystem, a nonlinear integral sliding mode surface and a fast reaching law are introduced to design the sliding mode controller, which improves the robustness of the system and weakens the chattering phenomenon. A speed difference feedback control algorithm is designed for the fast subsystem to suppress the vibration of the flexible joints and ensure the control accuracy. Finally, the effectiveness of the method is verified by simulation.