In order to study light weight legs for autonomous legged robots, we have constructed CARL, a compliant articulated robot leg. It contains an actuation package with a high torque to mass ratio termed ATLAS - AnTagonistic LADD Actuation System. It consists of an antagonistic pair of two CLADDs, Concentric Linear-to-Angular Displacement Devices. The actuators are in series with revolute polymeric springs for intermittent energy storage. The leg has four revolute degrees of freedom, two of which are actuated by ATLAS, one by a harmonic drive, and one is unactuated. We will be testing CARL's design under full dynamic loading, and validate control paradigms for compliant walking and running. Once CARL's design and control is proven, four such legs will be constructed towards a fully autonomous dynamically stable quadruped.
G. Mennitto, M. Buehler
The Compliant Articulated Robot Leg