Coordinated whole-body motion planning for a humanoid robot used on orbit and planetary surface

Abstract

To avoid large cost and danger of Extravehicular activity (EVA) and planetary surface exploration, a humanoid robot with high flexibility and mobility is under development. This robot is composed of two 7-DOF (degree of freedom) arms, a 1-DOF waist and two 3-DOF legs. This paper established the kinematics model and addressed whole-body coordinated motion planning methods for the robot, for different application cases: on orbit and planetary surface. For the former, there is no enough gravity (micro-or zero-gravity environment), the dexterity and workspace range are the main factors considered for the whole-body coordination. Combining the position-level and the velocity-level kinematics equations, the common manipulability of the two arms is analyzed, and the best reference workspace is determined. Inspired by the human motion, an appropriate pose (position and attitude) of the target for the two arms are then resolved according to the desired deflection angle of the waist with respect to the initial configuration. When the robot is used on the planetary surface, the gravity is required to be considered for keeping the robot stable during the mission. The coordinated whole motion is planned to adjust the robot's COM (center of mass position) position and make the ZMP (Zero Moment Point) satisfy the balance condition. Finally, the co-simulation model is established in ADAMS/Simulation environment. Simulation results of typical cases verify the proposed methods.