Biped gait synthesis based on dynamic parametrization

Biped locomotion has two characteristics: 1) repeating impact at the moment when the foot contacts with the terrain, 2) limitation to the torque of the ankle. The second is required in order to make the foot of the supporting leg stay on the terrain. Since the impulsive effect can be a disturbance which makes the robot fall down, the controller of the biped robot is required to make the undesired effect of the impulsive phenomenon as small as possible. Although it is common to design the controller with a high-gain feedback in order to eliminate the disturbance, the torque of the ankle is not limited. In the paper, a control method is proposed so that the system with impact is stabilized with limited inputs. A simple biped model controlled by the proposed controller is simulated numerically and the result shows the efficiency of the method.