Integration of vertical COM motion and angular momentum in an extended Capture Point tracking controller for bipedal walking

In this paper, we demonstrate methods for bipedal walking control based on the Capture Point (CP) methodology. In particular, we introduce a method to intuitively derive a CP reference trajectory from the next three steps and extend the linear inverted pendulum (LIP) based CP tracking controller introduced in [1], generalizing it to a model that contains vertical CoM motions and changes in angular momentum. Respecting the dynamics of general multibody systems, we propose a measurement-based compensation of multi-body effects, which leads to a stable closed-loop dynamics of bipedal walking robots. In addition we propose a ZMP projection method, which prevents the robots feet from tilting and ensures the best feasible CP tracking. The extended CP controller’s performance is validated in OpenHRP3 [2] simulations and compared to the controller proposed in [1]

A method for rough terrain locomotion based on Divergent Component of Motion

Abstract—For humanoid robots to be used in real world scenarios, there is a need of robust and simple walking controllers. Limitation to flat terrain is a drawback of many walking controllers. We overcome this limitation by extending the concept of Divergent Component of Motion (DCM, also called ‘Capture Point’) to 3D. Therefor, we introduce the “Enhanced Centroidal Moment Pivot point” (eCMP) and the “Virtual Repellent Point” (VRP), which allow for a very intuitive understanding of the robot’s CoM dynamics. Based on eCMP, VRP and DCM, we present a method for real-time planning and control of DCM trajectories in 3D