Motion planning of tbm disc cutter changing robot based on improved RRT-connect algorithm

Abstract

To solve the problems of narrow working space and complex obstacle environment of disc cutter changing robot in TBM, a motion planning method for TBM disc cutter changing robot based on an improved RRT-connect algorithm was proposed. Firstly, aiming at the shortcomings of the traditional RRT connect algorithm, such as many redundant nodes, unsmooth paths, and large randomness, the probability offset strategy, adaptive dynamic step strategy, path simplification strategy, and path smoothing strategy were proposed. Then the kinematics model of a new 8-joint TBM disc cutter changing robot was analysed, its motion space was determined, and the obstacle envelope model was completed. Finally, to verify the advantages of the proposed algorithm, a simulation comparison was made with the traditional RRT connect algorithm. The results show that the proposed algorithm reduces the running time by 72.0%, and the path length by 41.7%, which significantly increases the speed of motion planning and improves the smoothness of the planned path.