An Optimized Cable Layout Method for Cable-Driven Continuum Robots

Cable-driven continuum robots, inspired by natural biologies such as elephants and octopuses, have countless numbers of degrees of freedom, permitting them to carry out special tasks in confined space. However, the slender manipulator driven by cables also results in a significant number of driving motors integrated at the end of manipulator, which complicates the control of continuum robot. In this paper, to solve the problem, we optimize the cable layout based on the analysis of the cable length variation principle. First and foremost, a cable layout method of the shared motor is proposed, which can achieve the complete control of a continuum robot by employing half the number of motors. And then, the kinematics for the proposed cable layout is established based on the assumption of piecewise constant curvature. Finally, the experimental platform is constructed to evaluate the effectiveness of the proposed methods. The experimental results suggest that the optimized cable layout method can achieve the control of a double-section continuum robot by employing four motors. Moreover, it is worthy to be noted that, to some degree, the proposed cable layout method can effectively decrease the influence of gravity, which maximally improves 92.16% of the tip position accuracy.