H^∞ Control of a Quadruped Locomotion Robt Aiming at Dynamic Walking

Abstract

In the one period from legs landing to landing on the ground, a quadruped locomotion robot has two phases : the support phase and the swing phase. In the support phase, the foot is subjected to constraint force from the ground, and moment and force from the body, but not in the swing phase. Thus, in one period of walking, it is thought that the dynamics of the legs change greatly. It is desirable to construct a control design method taking account of the change in dynamics. In this paper, we deal with the change in dynamics as parameter perturbation. The H∞ control method, which is a robust control method against disturbance, is applied to the quadruped locomotion robot. First, we show the design method of H^∞ optimal tracking control. Next, we compare H^∞ and frequency-shaped (H²) optimal tracking control with conventional optimal tracking control in simulations and experiments.