On the Effect of Robotic Leg Design on Energy Efficiency

Abstract

In this paper, we study the effect of alternative leg designs on energy consumption in legged locomotion. Focusing on gaits with constant horizontal velocity and constant height we introduce models of two simplified parallel and serial designs with realistic mechanical and actuation parameters. The analysis yields the distribution of power demands in the leg workspace, leading to useful conclusions related to mechanical power antagonism and actuator electric losses. Mechanical antagonism occurs not only in parallel but also in serial legs causing extensive power waste, since one actuator contributes to the locomotion task and the other consumes power with no contribution to it. Based on the analysis, we propose a new leg design that minimizes the total actuation power consumption criterion given a nominal robot toe trajectory.