The ARL monopod II running robot:: Control and energetics

This paper presents the experimental implementation of an energy efficient "Controlled Passive Dynamic Running" strategy (CPDR) on a planar one-legged running robot with hip and leg compliance. The approach was introduced via simulations in [1], and tested via preliminary experiments [2]. The improved version described here permits running speed of up to 4.5 km/h with a total mechanical power expenditure of only 48W, which translates into a specific resistance of only 0.22. This is the highest efficiency among all actively controlled legged robots.