Evaluation of Hip Kinematics Influence on the Performance of a Quadrupedal Robot Leg

Abstract

As a major inspiration of biologically inspired systems, multi-legged robots have been developed due to their superior stability feature resulting from their large support polygon. The leg design of a majority of such robots is motivated by the skeleton of vertebrates such as dogs, or that of invertebrates such as spiders. Despite a wide variety of multi-pedal robots on the basis of the two aforesaid leg designs, a thorough comparison of the two underlying design principles remains to be done. This work addresses this problem and presents a comparative study for the two mammal-like and spider-like designs by looking at the joint torque profile, the responsive motion of the legs, and the thrust force applied by the robot. To this end, a set of performance indexes are defined based on the gravity compensation torque, the dynamic manipulability polytope and the force polytope, and evaluated in various leg configurations of the two designs.