Design and Kinematic Control of the Cable-Driven Hyper-Redundant Manipulator for Potential Underwater Applications

Abstract

Underwater manipulators are important robotic tools in the exploration of the ocean environment. Up to now, most existing underwater manipulators are rigid and with fixed 5 or 7 degrees of freedom (DOF), which may not be very suitable for some complicated underwater scenarios (e.g., pipe networks, narrow deep cavities, etc.). The biomimetic concept of muscles and tendons is also considered as continuum manipulators, but load capacity and operation accuracy are their essential drawbacks and thus limit their practical applications. Recently, the cable-driven technique has been developed for manipulators, which can include numerous joints and hyper-redundant DOF to execute tasks with dexterity and adaptability and thus they have strong potential for these complex underwater applications. In this paper, the design of a novel cable-driven hyper-redundant manipulator (CDHRM) is introduced, which is driven by multiple cables passing through the tubular structure from the base to the end-effector, and the joint numbers can be extended and decided by the specific underwater task requirements. The kinematic analysis of the proposed CDHRM is given which includes two parts: the cable-joint kinematics and the joint-end kinematics. The geometric relationship between the cable length and the joint angles are derived via the established geometric model for the cable-joint kinematics, and the projection relationship between the joint angles and end-effector’s pose is established via the spatial coordinate transformation matrix for the joint-end kinematics. Thus, the complex mapping relationships among the cables, joints and end-effectors are clearly achieved. To implement precise control, the kinematic control scheme is developed for the CDHRM with series-parallel connections and hyper-redundancy to achieve good tracking performance. The experiment on a real CDHRM system with five joints is carried out and the results verify the accuracy of kinematics solution, and the effectiveness of the proposed control design. Particularly, three experiments are tested in the underwater environment, which verifies its good tracking performance, load carrying and grasping capacity.

Dynamic Modeling of a Spatial Cable-Driven Continuum Robot Using Euler-Lagrange Method

“…However, these continuum robots can be controlled only by means of a finite number of DOF, which reduces the set of solutions. In this paper, many research works have been proposed in literature to accomplish this purpose [11][12][13][14][15][16][17][18].…”

An obstacle avoidance algorithm for space hyper-redundant manipulators using combination of RRT and shape control method

“…Symbols utilized in this study are summarized in Table A.1-A. 4, and acronyms utilized in this study are concluded in Table A. 5.…”

Visual Tracking Control of Cable-Driven Hyper-Redundant Snake-Like Manipulator

“…High flexibility of avoiding obstacles, good loading capacity, and easy maintenance should be taken into consideration for the structural design of robotic arms to satisfy the requirement of tasks under complicated working circumstances. A snakelike continuum manipulator with redundant DOF inspired by the biomimetic structure of vertebrate limbs has attracted increasing attention of researchers but limited to the drawbacks such as slight load capacity, imprecisely controlled and limited measurements, alleviated after the cable-driven technique introduced [3].…”