A passive-assist design approach for improved reliability and efficiency of robot arms

The purpose of this paper is to examine a passive-assist design approach for improving the performance of robot arms and unmanned ground vehicles (UGVs) with respect to reliability, utility, and efficiency. Specifically, a procedure that alters the mechanical design of a robot arm to incorporate springs optimized to reduce the maximum motor torque, or energy, required to perform a specified maneuver is proposed. By reducing the maximum motor torque required, the reliability and utility of the motors (and by extension the entire UGV) are increased. Our joint model includes both a non-backdrivable worm gear and a static DC motor. Initial results for a one link arm indicate that this procedure can reduce maximum required torque by 50.9% and energy consumed by 8.5%.