Kinematics and control of a cable-driven snake-like manipulator for underwater application

Abstract. In view of the large volume, complex structure, and poor performance of traditional underwater manipulators in some complicated underwater scenarios, a cable-driven snake-like manipulator (CDSLM) is proposed. In this paper, the kinematics model of the proposed CDSLM is firstly established, which can be decomposed into three parts: motor–cable kinematics, cable–joint kinematics, and joint–end kinematics. A tip-following algorithm is then presented to weave through the confined and hazardous spaces along a defined path with high efficiency. The main merit of the algorithm is that only the terminal section variables need to be calculated and recorded, which solves the problem of expensive computational cost for the inverse kinematics of snake-like manipulators. Finally, evaluation indexes of the path-following performance are proposed to evaluate the effect of the tip-following algorithm. Simulations of the path-tracking performance are carried out using MATLAB. The results demonstrate that the average computation time is about 1.6 ms, with a deviation of less than 0.8 mm from the desired path, and the stability and effectiveness of the tip-following algorithm are verified.