Research on Snake-Like Robot for Cutter Inspection in Tunnel Boring Machine.

While the applications of tunnel boring machine (TBM) are growing due to its high performance, the working mode of “robot replacing labor” is continuously increasing because of TBM’s harsh and confined space. Thus, snake-like robot, which is with superior dexterity and obstacle avoidance ability, are highly suitable for TBM cutter inspection. However, its large number of degrees of freedom (DOFs) makes the inverse kinematics and control strategy very complex. Therefore, the paper researches the efficient kinematics algorithm based on the geometric method, including tip-following and serpentine-scanning methods. Tip-following method achieves to send the end-effector to the target area, while serpentine-scanning method promises the scanning inspection on every cutter. Because of the particularity of the geometric method in this paper, the local coordinate frame and joint space are abandoned, but the “link eigen vector” is utilized to construct a simpler and more direct kinematic model. Simulation and experiment results show the proposed methods satisfy the real-time control and obstacle avoidance. Especially the engineering test shows the snake-like robot can meet the quick and reliable inspection task of the cutter and cutterhead.