Locomotion control of a humanoid robot using a biped walking pattern based on physical interaction

This paper describes a biped walking pattern for physical interaction between a human and humanoid robot. The study of the physical interaction between robots and humans is an important research field when considering a future society where humans and robots must coexist. In this paper, to move the humanoid robot in the direction intended by the human, the previous method of generating a walking pattern is extended to a method of generating a walking pattern suitable for physical human-robot interaction. When the human applies disturbance to the robot, the robot naturally move in the direction of applied disturbance to recover balance. The applied disturbance is measured by the capture point. To stabilize the perturbed capture point, the desired Zero Moment Point (ZMP) is calculated by using the capture point control. This desired ZMP is tracked by the walking pattern generator. The walking pattern generator automatically calculate the center of mass trajectory, which satisfies the ZMP constraint, by model predictive control. The proposed method was applied to the humanoid robot DRC-HUBO+ and verified that it can be used for physical human-robot interaction.