Walking control strategy for a planar under-actuated biped robot based on optimal reference trajectories and partial feedback linearization

Abstract

This paper deals with a control approach for a planar under-actuated biped robot based on optimal reference trajectories generation and partial feedback linearization. The basic feature of the proposed strategy is to generate, for the actuated joints, on-line optimal reference trajectories with respect to the zero dynamics. Then partial feedback linearizing control enables the tracking of these trajectories, which results in the convergence of the zero dynamics to a stable limit cycle. Simulation of a forward walking at constant mean velocity is investigated to illustrate the efficiency of the proposed scheme.