1 Introduction

Abstract

Land locomotion can be broadly characterized as quasi-static or dynamic. Quasi-static equilibrium implies that inertial (acceleration-related) effects are small enough to ignore. That is, motions are slow enough that static equilibrium can be assumed. Stability of quasi-static systems depends on kee** the gravity vector through, the center of mass, within the vehicle’s polygon of support determined by the ground-contact points of its wheels or feet. Energy input is utilized predominantly in reacting against static forces. Such systems typically have relatively rigid members, and can be controlled on the basis of kinematic considerations.