A Small Envelope Gait Control Algorithm Based on FTL Method for Snake-Like Pipe Robot

Abstract

Benefit from the characters of multi-DOFs and slender body, the snake-like robot is flexible and suitable for detecting the unstructured, narrow, tough ancient pipes with rectangular cross section. However, the motion envelopes of the existing gaits of the snake robot are quite large. It may cause collision between the robot and the pipes or obstacles and lead to motion failure. Aiming to solve the problem mentioned above, a small envelope gait (SEG) based on the follow-the-leader (FTL) method is proposed to reduce the envelope of the path for avoiding the collision between the robot and the pipe walls or the obstacles. The SEG is realized on our existing prototype, a novel active-passive (AP) type snake-like pipe robot which has both active and passive modules. Firstly, the kinematics model of the AP type snake robot is build. Secondly, the SEG control algorithm is proposed for controlling the snake body to follow the path of head. Lastly, experiments are taken both in the laboratory and ancient pipes to verify the effectiveness of the SEG control algorithm.