DESIGN OF A ROBUST DYNAMIC GAIT OF THE BIPED USING THE CONCEPT OF DYNAMIC STABILITY MARGIN

A computational technique for designing a physically realizable robust dynamic gait for a planar biped robot is developed. Firstly, a feasib le set of gaits was constructed to satisfy the periodicity of the bipe d locomotion. Then the concept of dynamic,stability margin is introduc ed based on the robustness of a gait with respect to the external dist urbances. Using that margin, we can assess the robustness of each dyna mic gait in the feasible set. It is found that the parameter, called f oot strike time margin, representing the readiness of the foot strike has a close positive correlation with the dynamic stability margin. We obtain a robust gait with respect to the external disturbance by maxi mizing the foot strike time margin. The robustness of the optimal gait is confirmed by the behavior of the gait after application of linear impulse as well as by the examination of the largest eigenvalue at the perturbed state.