Abstract
Real-time gait change is necessary for humanoid robots for emergency. We propose a new gait change method using modification criteria map. The stable gait change is generated by adjusting the amount of the ZMP modification according to the timing of stop command. The modified ZMP trajectory is given so that the humanoid robot can change the current motion without falling down. The modification criteria are defined from the relation between the predicted ZMP trajectory using a preview controller and the support polygon. The preview controller employs Table-Cart model and it derives Center of Mass(CoM) trajectory from ZMP reference in real-time. We make the map of relation among the ZMP modification length, the modification timing and the timing of the stop command for stable gate modification. The robot can execute the best motion referring to the predefined map. In this method, the humanoid robot can stop or change step length immediately within one step. The validity of the proposed method is confirmed by experiment using a humanoid robot HRP-2.
