Planning Gaits for Underactuated Compass-Biped Robot With Torso

Abstract

A structured approach to gait planning for a planar underactuated 3-link biped robot is presented. The method of virtual holonomic constraints (VHC) is employed to this end. It is shown how this method effectively reduces the dimensionality of the problem and allows for the biped s dynamics to be re-written in reduced form. The reduced dynamic system is then used to structure requirements for the existence of periodic gait-cycles in the robot s state-space. The gait planning task is then solved in a structured manner by organizing a numerical search that finds parameterizations of the VHCs that lead to nominal gait cycles for the biped.