Stability analysis of a simple walking model driven by an oscillator with a phase reset using sensory feedback

This paper deals with the analytical examination of the dynamic properties of the walking motion of a biped robot based on a simple model. The robot is driven by rhythmic signals from an oscillator, which receives feedback signals from touch sensors at the tips of the legs. Instantly, the oscillator resets its phase and modifies the walking motion according to the feedback signals. Based on such a simple model, approximate periodic solutions are obtained, and the stability of the walking motion is analytically investigated by using a Poincare´ map. The analytical results demonstrate that the modification of the step period and the walking motion due to the sensory feedback signals improves the stability of the walking motion.