Experimental validation of optimal load-allocation control in pace gait ladder decent motion for Multi-Locomotion Robot (MLR)

This paper presents an experimental validation of optimal load-allocation control in pace gait ladder decent motion for a Multi-Locomotion Robot (MLR). Since a closed chain is formed by the robot links and the vertical ladder, if using position control, a large change of internal stress will be generated inside the closed chain due to the unavoidable position errors between end effectors and their target rungs on the ladder. The internal stress has no contribution to equilibrate the robot load, however it influences a lot of the energy cost of joints inside the closed chain. Thus, an optimal load-allocation control is proposed for multi-contact robot motions by adjusting the internal stress using one or some important joints. Compared with the simulation results introduced in a previous work [1], in this paper, the robustness and effectiveness of the optimal load-allocation control is experimentally verified by the MLR in a predesigned pace gait ladder decent motion.