A simple stability study for a biped walk with under and over actuated phases

Abstract

We numerically study the orbital stability with Poincare map in seven dimensions of a cyclic dynamically stable gait which is composed of single and double support phases and impacts. Physical constraints as ground reactions and limited torques are taken into account with the control. The double support is used to improve the stability of the biped. Numerical tests are presented, where the maximum modulus of the eigenvalues of the linearized Poincare map around the fixed point of the periodic motion is checked with the power method to be less than one, to ensure stability.