START, STOP AND TRANSITION OF VELOCITIES OF AN UNDER-ACTUATED BIPEDAL ROBOT WITHOUT REFERENCE TRAJECTORIES

Abstract

In this paper, we propose a control strategy allowing us to perform the transition of velocities included in [0 m/s; 1 m/s] for the dynamic walking of a virtual under-actuated robot (RABBIT) without reference trajectories. This strategy of control enables us to carry out the transition from stop towards walking and the reverse process. The interest of this method is that, on the one hand, the intrinsic dynamics of the system are exploited by using a succession of active and passive phases and, on the other hand, the control strategy is very simple to implement on-line. Moreover, we apply this method by taking into account the technological limitations related to experimentation on the real robot such as dry and viscous frictions, maximum torque, and maximum power.