Bioinspired Control of Walking with Toe-Off, Heel-Strike, and Disturbance Rejection for a Biped Robot

Human-like features, like toe-off, heel-strike, and disturbance rejection, can enhance the performance of bipedal robots. However, the required control strategies for these motions influence each other, and few studies have considered them simultaneously. Humans can walk stably with toe-off and heel-strike even after experiencing disturbances. Thus, we can study human control strategies, and then, apply them to a bipedal robot. This paper proposes a bioinspired control method to realize stable walking with toe-off and heel-strike for a bipedal robot even after disturbances. First, we analyze human walking and obtain some control strategies. Then, we propose a pattern generator and a walking controller to mimic these strategies. The pattern generator can predefine the zero-moment-point to plan the center of mass trajectory and determine appropriate foot placement. The controller adjusts torso acceleration to make the support leg compliant with the external disturbances. The controller also achieves toe-off and heel-strike in cooperation with the pattern generator. Finally, the validity of the proposed method is confirmed through simulations and experiments.