Design and analysis of 3-UPU wave compensation platform based on improved sliding mode control

In this paper, the 3-UPU parallel mechanism platform is designed through SolidWorks software, and the assembly model of the 3-UPU parallel mechanism is imported into the Simulink environment through Simscape/Multibody. Aiming at the heave motion of the ship at sea, an improved sliding mode controller is designed in this research, named as global fast terminal sliding mode controller, to track and compensate the ship heave motion data. In order to verify the effect of the designed controller, the traditional PID controller is selected for comparison. The results show that: when the traditional PID controller is used to track and compensate it, if the appropriate parameters are selected, the tracking effect is better, the tracking error is small but fluctuates up and down, and the tracking error accuracy is poor. After the introduction of the improved sliding mode controller proposed in this paper, when entering the stable stage, the tracking compensation effect of the improved controller is better than that of the traditional PID control, and the tracking error is smaller than that of the traditional PID control. The global fast terminal sliding mode control has good robustness and can be applied to the ship heave compensation system.