Dynamic compliant quadruped walking

This paper presents a new dynamic walking controllers for quadrupedal robots with compliant legs. The algorithm implements a "walking bound" gait, requires only one actuator per leg at the hip, and commands a constant hip velocity during stance. The algorithm has been implemented successfully on our Scout II quadruped robot and has yielded stable walking for ranges of operating conditions with minimal reliance on feedback. The experimental data is used to illustrate important considerations on torque generation that need to be taken into account both for successful implementations and realistic modeling of legged robots. In addition, we quantify the energetics of our walking experiments via the specific resistance and document dramatic differences between mechanical and electrical power.

1 Introduction

To date most legged robotics research has focused on the study and implementation of systems with many actuated degrees of freedom. This has often yielded robots whose full range of motion was difficult to exploit, due to high system complexity, high weight, and to a lack of formal methods for the development of robust control schemes.