Biped walking control using a trajectory library

This paper presents biped walking control using a library of optimal trajectories. The biped walking control problem is formulated as an optimal control problem. We take advantage of a parametric trajectory optimization method to find the periodic steady-state trajectory in regular walking. Then we use Differential Dynamic Programming (DDP) to generate a library of optimal trajectories and locally linear models of the optimal control law, which are used to construct a more global control law. The proposed controller is compared with a trajectory tracking controller using optimal gains. The utility and performance of the proposed method is evaluated using simulated walking control of a planar five-link biped robot.