Structure design and control research of a novel underwater cable-driven manipulator for autonomous underwater vehicles

Aiming at the requirements of lightweight, low energy consumption and low inertia of the manipulators for autonomous underwater vehicles, this article presents a novel underwater cable-driven manipulator for autonomous underwater vehicles. Thanks to the cable-driven mechanism, the motors are installed remotely from joints, which can reduce the disturbance of the motion of the manipulator to the system and extend the operation time under the premise of limited energy. Cable-sheath mechanism is used to realize the motors to be fixedly mounted on the base (postposition). A prototype named Polaris-II is assembled, and experiments are carried out with the time-delay control scheme. Although the control effect of a single time-delay controller is good, there exist large errors caused by the reversing of joints. Therefore, a fuzzy compensator is designed and added to the time-delay controller to suppress the large errors. The experimental results show that the time-delay controller with a fuzzy compensator has a good inhibitory effect on the large errors while maintaining good control effect.