Obstacle-negotiation performance on challenging terrain for a parallel leg-wheeled robot

High obstacle-negotiation performance of quadruped robots for the challenging terrain is strongly demanded in some fields, including payload delivery and disaster relief. In this study, a parallel leg-wheeled robot with the high mobility performance on targeted types of rough terrain is proposed. In contrast to other obstacle-negotiating robots, the strength of this robot is that it has adequate over-obstacle capabilities with a horizontal body in terms of different obstacle shapes, which mainly derives from the multi-DOF (degree of freedom) flexible locomotion of legs and the independent actuated wheels as end effectors. Particularly for a steep terrain where a large inertia robot negotiates it with low efficiency and stability, the proposed step-over gait, combined with static gait and wheeled locomotion, improves the over-obstacle efficiency and maintains pose stability. Finally, simulations and experiments verify the performance on negotiating the diverse obstacles with level body over challenging terrain.