Role of deceleration effect in efficient and fast convergent gait generation

This paper discusses the problem of how to achieve high speed, energy efficient, and fast convergent limit cycle walking. We newly introduce the convergence speed of the generated gait as a criterion for evaluation. Through mathematical and numerical investigations, we clarify the role and importance of deceleration effect in fast convergent gait generation. First, we generate ballistic gaits of the simplest 1-DOF active walker by applying a simple control torque, and show that the stance phase is destabilized in the case only of acceleration effect. Second, we propose another method for generating a fast convergent gait by adding deceleration effect and investigate the validity through numerical simulations. Furthermore, we extend our analysis to the cases taking joint viscosity and time delay into account and discuss the effects on the gait properties.