Optimal Trajectory Planning for Brachiation Robot on Ladder With Irregular Branches

Abstract

This paper deals with control of the brachiation robot. The brachiation is a type of mobile robot that moves from branch to branch like a long-armed ape. Here, as a new innovation, Pontryagin’s minimum principle is used to obtain the optimal trajectories for two different problems. The first problem is “Brachiation between fixed branches with different distance and height” and the second is “Brachiating and catching the moving target branch”. Theoretical results show that the control effort in the proposed method is reduced by 25% in comparison with the “Target Dynamics” method which was proposed in prior articles for this robot. The obtained optimal trajectory also minimizes the brachiation time. A PD controller is investigated for tracking the proposed trajectories. Lastly, theoretical results are shown and validated with experimental test.