Biped Robot Pelvis Kinematics Estimation based on the TouchPoint Updating Method This study proposes a bipedrobot pelviskinematics estimator based on the touchpoint updating method. Because the pelvis frame is used as the base coordinate for the control, the kinematics of it with respect to the global frame should be precisely estimated. To this end, it was necessary to know where the robot made contact with the ground. The touchpoint concept was introduced as the temporal contactpoint, which was instantly the robotxe2x80x99s rotation center. By updating this point, the bipedu0027s global pelviskinematics could be estimated. The proposed estimator was implemented into the actual robot, and its superiority was verified through groundtruth data.

MultiContact Stabilization of a Humanoid Robot for Realizing Dynamic Contact Transitions on Noncoplanar Surfaces This paper focuses on a stabilization control for multicontact motion which enables a humanoid robot to locomote by realizing dynamic contact transitions on nonflat environment. In the stabilization process of the multicontact motion, the desired ZeroMoment Point (ZMP) is modified by the position of the Divergent Component of Motion (DCM) error with respect to the 3D Center of Mass (CoM) motion generated from the force distribution ratio. The contact wrench of each endeffector is determined by quadratic optimization considering the centroidal dynamics and contact friction constraints so as to satisfy the modified ZMP. Each endeffector is controlled by optimized force reference through a projection of null space by force distribution ratio. We propose a multicontact stabilization framework which can be designed not only to generate 3D CoM motion but also the CoM position estimation and the optimal force distribution around the reference ZMP in a unified manner from a balance controller, by using the force distribution ratio. The effectiveness of proposed method is validated by a quadruped locomotion leaning against a vertical wall using the joint position controlled humanoid HRP5P in a dynamic simulator.