A Bipedal Walking Robot with Efficient and Human-Like Gait

Here we present the design of a passive-dynamics based, fully autonomous, 3-D, bipedal walking robot that uses simple control, consumes little energy, and has human-like morphology and gait. Design aspects covered here include the freely rotating hip joint with angle bisecting mechanism; freely rotating knee joints with latches; direct actuation of the ankles with a spring, release mechanism, and reset motor; wide feet that are shaped to aid lateral stability; and the simple control algorithm. The biomechanics context of this robot is discussed in more detail in [1], and movies of the robot walking are available at Science Online and http://www.tam.cornell.edu/~ruina/powerwalk.html. This robot adds evidence to the idea that passive-dynamic approaches might help design walking robots that are simpler, more efficient and easier to control.

I Introduction

A robot can help test theories of locomotion in ways that are impossible with human subjects; in a robot, one explicitly knows the control strategies being employed and can thus evaluate their qualities. On the other hand, machines that are simple, efficient and easy to control are more likely to be practical as robots. Walking robots based on the mainstream control paradigm of precise jointangle control seem deficient for both purposes by their large energy demands which are not human like and limit autonomous operation times. In contrast, walking robots based on passive-dynamic principles can have human-like efficiencies, and thus more practical energy use requirements [1]. We describe one such powered robot here.