Dynamic Gait Hexapod

A hexapod (6-legged) robot is a classic beginner robotics project. I love the way they look and feel, but they're so slow! All of their motions have to be perfectly choreographed, and they're severely overconstrained. I want to make a hexapod that doesn't just walk-- it gallops.

Cockroaches spend very little time on the ground while they're running. That's because they have springy legs, which rebound their body off the ground again and again. Maintaining their gait requires very little energy, and on top of that, it's extremely robust on rough terrain.

Why can't a robot do that? Let's build it!

Task: Design a final project, using as many of the class design tools as possible.
It doesn't matter if it's a little cooky. The point is to think of something which falls within the scope of the class, and to get a feel for the design tools available to you.

I've been dreaming about this for a while now. Here are some sketches of what I want to accomplish.

Clockwise, from top right: Burmester linkage leg design; a single leg on the hexagonal body, to scale; some resonance-related mathematics of questionable utility; a combined top/side view of the leg mechanism with servo.

The legs will be Burmester straight line linkages, so that the whole body can translate downward along a straight trajectory. This degree of freedom will be the spring-loaded degree of freedom.

I used Linkage, a free 2D CAD package for visualizing and designing planar linkages, to model my Burmester straight line linkage.

Inkscape overhead view

I did my best to make a model to scale in Inkscape, which provides some insight into the constraints which the joints will need to satisfy so that they do not collide with each other.

Next week: Press fit design! Maybe I will be able to use press-fit components to simplify the construction of these relatively complex legs. Otherwise, fastener placement will become a major roadblock.

Project 1

MAS.862 Final Project Proposal