Fuzzy control of a four-rope-driven level-adjustment robot considering all constrained situations

In the paper, we aim to design a controller for the four-rope-driven level-adjustment robot to adjust eccentric payload to level and keep the rope tension balanced. As the robot´s actuators can only move in a certain range, it is necessary for the controller to judge whether the actuators´ movement becomes constrained or not. Further, different control strategy should be taken to handle different situations. The controller is composed of two control modules, each of which regulates one diagonal of the payload´s upper surface. Each control module consists of nine fuzzy sub-controllers, and each sub-controller deals with a particular situation. By selecting appropriate sub-controllers automatically, each control module can deal with different situations. Experiment results show that the controller is effective and practical.