Abstract
One key problem to achieve a dynamically stable walking motion with biped robots is to measure and control the actual state of the robot with respect to its environment. Dynamically stable walking on unstructured terrain and fast walking can only be achieved with an orientation sensor. The control system of the biped robot “Johnnie” is designed such that the orientation of the upper body is controlled throughout all phases of the gait pattern. Furthermore, a sophisticated measurement and control of the foot torques has been implemented. In this way, the interaction forces and torques between robot and environment are controlled and tilting of the foot is avoided.