The Simplest Walking Robot: A bipedal robot with one actuator and two rigid bodies

TL;DR

This paper introduces Mugatu, a minimalistic 1-DOF bipedal robot with a single actuator, demonstrating stable walking, steering, and energy efficiency, simplifying design and control for small-scale bipeds.

Contribution

The paper presents the first 1-DOF, hip-actuated bipedal robot with a simple mechanical design and autonomous walking capabilities, enabling exploration of minimalistic bipedal locomotion.

Findings

Self-contained and autonomous operation

Open-loop stability over various inputs

Effective control of heading and movement

Abstract

We present the design and experimental results of the first 1-DOF, hip-actuated bipedal robot. While passive dynamic walking is simple by nature, many existing bipeds inspired by this form of walking are complex in control, mechanical design, or both. Our design using only two rigid bodies connected by a single motor aims to enable exploration of walking at smaller sizes where more complex designs cannot be constructed. The walker, "Mugatu", is self-contained and autonomous, open-loop stable over a range of input parameters, able to stop and start from standing, and able to control its heading left and right. We analyze the mechanical design and distill down a set of design rules that enable these behaviors. Experimental evaluations measure speed, energy consumption, and steering.