Dynamic Walking on Uneven Terrain Using the Time-Varying Divergent Component of Motion

作者：Hopkins Michael A^*; Hong Dennis W; Leonessa Alexander

来源：International Journal of Humanoid Robotics, 2015, 12(3): 1550027.

DOI：10.1142/S0219843615500279

• Humanoid locomotion
• divergent component of motion
• dynamic planning
• model predictive control
• momentum control

This paper presents a framework for dynamic walking on uneven terrain using a novel time-varying extension of the divergent component of motion (DCM). By varying the natural frequency of the DCM, we are able to achieve generic CoM height trajectories during stepping. The proposed approach computes admissible DCM reference trajectories given desired zero moment point (ZMP) plans for single and double support, permitting both flat-footed and heel-toe walking. Real-time planning is accomplished using reverse-time integration of the discretized DCM dynamics over a finite time horizon. To account for discontinuities during replanning, linear model predictive control (MPC) is implemented over a short preview window, enabling smooth transitions between steps. DCM tracking control is achieved using a time-varying proportional-integral controller based on the virtual repellent point (VRP). The effectiveness of the combined approach is verified in simulation using a 30 DOF model of THOR, a compliant torque-controlled humanoid. We demonstrate dynamic locomotion on uneven terrain and heel-toe walking using a complementary whole-body controller to track the corresponding VRP forces.

• 出版日期2015-9
• 单位美国弗吉尼亚理工大学(Virginia Tech)