CRRIK: A Fast Heuristic Algorithm for the Inverse Kinematics of Continuum Robot

The inverse kinematics (IK) of continuum robot is a challenging work due to the hyper-redundant DOFs and the narrow and complex operating environment. However, many of the currently available algorithms are with the disadvantage of complex solving processes, low computational efficiency, and even singular problems or low convergence rates. Referred to the Forward and Backward Reaching Inverse Kinematics (FABRIK) algorithm, a novel heuristic algorithm is proposed in this paper, which is called Continuum Robot Reaching Inverse Kinematics (CRRIK). The CRRIK algorithm is with the advantages of high convergence rate and low computational cost, which are suitable for real-time applications. The forward iteration of CRRIK is inspired by the physical process of pulling a rope with a fixed end, which is straightforward and obvious, avoiding complicated nonlinear operations. Furthermore, the joint angle boundary condition and obstacle avoidance can also be implemented in the backward iteration, broadening the application scenarios of the CRRIK algorithm. The effectiveness of the CRRIK algorithm is demonstrated through a five-segment continuum robot’s trajectory tracking and obstacle avoidance simulation. And a comparison between the CRRIK algorithm and some of the most popular IK methods is also presented to validate the performance of CRRIK.