Stability polygons reshaping and morphing for smooth multi-contact transitions and force control of humanoid robots

Abstract : In this paper we provide hindsight on how to use the information provided by the explicit computation of the stability polygon and build on task-based QP controllers to achieve both stable multi-contact slow transitions and force limitation with a level of force control. This entails computing stability polygons with unilateral and bilateral contacts and devising a method to continuously constrain the CoM position throughout multi-contact motion in order to effectively regulate the forces applied on the environment while avoiding hard constraints on the CoM and discontinuity between stances.