Planning approach and local reactivity for 3D Operational space control of 3D bipedal robots with flexible feet

This paper presents an approach to control gaits of humanoid bipedal robots in operational space without reference trajectories. This control strategy is based on the planning of the sequential events during the walking process. The aim of this study is to propose a new control strategy which is more reactive, permits a precise coordination of both legs during the double stance phase and the generation of dynamic 3D walking of an anthropomorphic biped with flexible feet. Based on homogeneous transformation matrices, the control strategy integrates three aspects in one unified representation: structural parameters of the robot, measurements given by sensors, planning of the sequential events during the different stages of the walk.