Passive Bipedal Walker

Building a passive bipedal walker was by far the most challenging, insightful, and meaningful project I have explored.

A passive bipedal walker walks down a shallow slope without using motors. Walking is commonly defined as a motion characterized by alternating swing and stance phases. Getting a passive walker to walk is quite challenging because its mechanical design must not only support its motion but also achieve a perfectly tuned mass distribution. In building the project, I had to consider tolerances, mass distribution, friction (I used ball bearings and a steel axle), the masses of different filaments in printing, and surface textures.

A key part of making a passive walker is choosing how to achieve foot clearance. Humans achieve foot clearance while walking by using their knees, but for my design, I chose to use curved feet. In CAD, I designed a foot curvature with a specified radius in two planes (like a spherical surface) and researched how changing the curvature of the feet can affect how the walker walks.

I came up with a new method of controlling a passive gait by modifying foot curvature, and even was able to make the walker turn as it walked by independently modifying the curvature between the feet. To test different walker curvatures, I created a swappable foot design in Fusion.

The details of my research process and results are available in my paper: