Bipedal Bird Robot

The challenge was to create a walking robot that stood on two legs. In a team of four, I designed and manufactured a bipedal bird robot using a small motor, gearbox and linkage system. The body of the robot was laser cut on duron and the motor crank and the bird's feet were 3D printed.

We found that designing a linkage that produced movement that would keep the robot balanced hinged on more than just the path of the coupler curve (the feet of the bird). Tracking the position and angle of the feet, the relative position of the body to the supporting foot and the position of one foot relative to another proved to be essential to ensure a reliable and balanced movement.

You can check out our project report with a detailed look at our design development and engineering analysis here.

Lessons Learned

This project really showed me the value of iteration. We managed to get early prototypes working (the prototype produced a barely balanced walk that was more of a waddle) and that meant we could focus on improving our design with each new version and rounds of testing. Our final design was able to walk reliably thanks to the iterations and prototyping we went through early on.

I learnt not to fall in love with my ideas. In order to get enough iterations to allow for our success we had to give up on many ideas. In particular, there was a four-bar linkage design I had come up with that almost worked. The bird was loosing balance, but just barely, at one point in the motion and we tried to fix that by changing the feet. The new foot design required an overnight 3-D print and it proved ineffective. The new feet were a bit too big and were interfering with each other, causing more problems. At this point, we were very close to our deadline and didn't have the time to print another pair of feet. The solution was to change the linkage design. Laser cutting new links would be faster and would allow us to get more iterations before the final. Even though the original linkage was more exciting, it provided a more challenging motion – more akin to that of an actual bipedal animal, in order to succeed we had to move away from that idea and try something simpler we knew had a better chance at working. I was excited to try the harder, cooler approach first, get into trouble, and then figure out how to get out of 'trouble' and still be successful. We took a risk and knew when to try something different.