Research on dynamic path planning and synergistic following algorithms for a snake-arm system with flipping and feed motion

Abstract

There exists a snake-arm system that can operate in special confined spaces with narrow holes. The system consists of a flipping base and a snake-arm manipulator. It offers high flexibility but also presents great difficulties in solving inverse kinematics. In this paper, we propose a synergistic motion scheme for the snake-arm system to pass through small holes into confined spaces. Firstly, we present the kinematic model. Next, to guide the snake-arm manipulator smoothly into indoor spaces, we propose a dynamic path planning method. We divide the following path into three parts: obstacle avoidance path, feeding path, and transition path. Each part is planned individually, and a procedural method is used to combine them. Unlike traditional static paths, the feeding path and transition path can adaptively adjust as the snake-arm system moves. To ensure strict adherence to the dynamic path during follow-up motion, we propose a dynamic path synergistic following algorithm specifically designed for this type of system. Compared with existing algorithms that follow static paths, the new algorithm will not be constrained by the single feed direction of the snake-arm system. Simulation tests verify the effectiveness of the algorithm, which achieves an endpoint positioning accuracy of 10⁻⁷ mm for the snake-arm manipulator. Additionally, it expands the workspace of the snake-arm system from 1.59 m³ (horizontal mode) to 7.19 m³, while reducing outdoor height occupation by 21.54 % compared to vertical motion. Finally, in comparative tests, the proposed algorithm excelled in computational efficiency, accuracy, and stability.