Actuated Dynamic Walking in a Seven-Link Biped Robot

The authors have previously described a method for enabling fully actuated biped walking without prescribing joint angle trajectories or imposing kinematic constraints between joints. This method was hypothesized to offer a more natural-looking bipedal gait and a higher locomotive efficiency relative to methods requiring accurate joint trajectory tracking. In this paper, the authors present experimental evidence to support both hypotheses. Specifically, the authors describe the design of a seven- link bipedal robot appropriate for the previously proposed control method; present the implementation of the "nonkinematic" control approach on the biped robot; demonstrate (with data, photo- graphic sequences, and video) the "relaxed" style of walking resulting from the control method; and experimentally characterize the locomotive efficiency of the biped in terms of the mechanical cost of transport. The latter results are compared to corresponding measures reported elsewhere in the literature.