Continuum Manipulator With Rigid-Flexible Coupling Structure

Pneumatic-driven soft manipulator has great flexibility and adaptability, which makes it can do some complex tasks that traditional robots can't do such as minimally invasive surgery, detection, search and rescue, et al. However, due to the low stiffness of pneumatic-drive soft manipulator, it faces some problems such as poor load ability and vibration, and the structural flexibility of the soft manipulators make the kinematics modeling complicated. To solve these problems, in this letter, we proposed a novel structure of continuum manipulator that couples with rigid and flexible structure, i.e., rigid-flexible coupling manipulator (RFCM). The RFCM consists of three modules, each containing a rotating unit and a bending unit, so that the RFCM can move flexibly in the workspace. Compared with the purely soft manipulators, RFCM has higher stiffness, and the unique driving structure enables it to have simpler control logic. In addition, we proposed an inverse kinematic solver based on numerical optimization to deal with the redundant problem of continuum manipulators. Preliminary experiments in both computer simulation and physical demonstration of RFCM are conducted, and the proposed kinematics algorithm can effectively establish the mapping from workspace to joints space for RFCM.