Gait generation of compass-type biped robot via angle control of hip joint

In this paper, we consider the walking control problem of a point-contact underactuated robot. A stride of each step plays an important role in walking of underactuated robots. Strides of such robots are determined only by joint angles, however, walking via joint angle control is a difficult problem. Particularly, a sufficient condition for underactuated walk is presented for the case that the specific mass distribution condition is satisfied. Moreover, the walking control method via inverse optimal control using a control Lyapunov function(clf) is proposed. The effectiveness of the proposed method is confirmed by an experiment. Finally, we evaluate the energy efficiency of the proposed walking by the specific resistance.