16-199: Building the Future
Spring 2004

Biped Robot SURG Project

Project Description
With the financial assistance of a SURG grant and under the advising of Prof. Chris Atkeson, Jack Wu and I set out to build a bipedal robot.

To make the project as realistic as possible, we decided upon a static-walker design wherein minimal inertial sensing would be required and the robot instead maintains static equilibrium throughout its entire step cycle. This greatly simplified the design and allowed us to begin immediately without extensive theoretical analysis.

Our goal was to build a small prototype out of legos and then construct a larger version with a metal frame. We hoped to be able to use a mostly-completed frame built by an earlier project of the robotics club, since both of us are CS majors and don't possess all the mechanical engineering skills necessary to design something of this complexity.

Project State
We were able to construct a biped using legos for the structure, a basic stamp for high level control, a servo controller interfaced to the basic stamp, and several servos. It follows a pre-programmed step pattern of "key-frames" of servo positions with some intermediate smoothing. At one point, we had it walking quite well, but what appear to be some mechanical problems have since set in, and it now frequently falls over.

Some brief political issues over ownership of the robotics club biped base plagued us briefly, but we eventually got access to it. Unfortunately, we quickly saw that the particular servo motors it used offered clearly insufficient holding torque and that newer/better ones we had that could provide the necessary power would not fit the base, even with some modifications. We were therefore forced to design and build a base of our own. We designed a base and sent the plans off to a machinist, but still have yet to finish the physical construction.

Future Intentions
We definitely intend to continue this project and have applied for another SURG grant for the coming fall. It is our desire to complete the larger static walker over the summer and actually begin to attempt a dynamic-balance version in the fall.

Relevant Links

Other links, including those we found useful while researching bipedal motion, will be posted later, time permitting.