Killer Running Robots Will Kill Us All

Ugh -- skynet references :)

University of Michigan's MABEL runs free for over 110 steps! In our opinion, this is the most realistic, human-like running achieved on a robot. It has a very satisfying feel to it. The robot just moves right. It is up in the air for more than a third of the duration of step. The height off the ground is right. Whereas other robots had their feet maybe one sixth of an inch off the ground, MABEL is 3 to 4 in inches in the air. The motion of the hip, which is like a bouncing ball, and the pitching of the torso give you the sensation of running. It all just makes you say, that is running.

Feedback algorithm for running was designed by Koushil Sreenath as part of his PhD dissertation. The detailed model used in the work was developed by Hae-won Park as part of his PhD dissertation.

For the feedback control aficionados, we used a nonlinear, compliant hybrid zero dynamics controller with active force control, running in real-time. How about that! MABEL weighs over 65 Kg, has a heavy torso (40 Kg), has point feet, and a cable-driven transmission system with compliance. This makes it a challenging machine to control. The Hybrid Zero Dynamics (HZD) framework was instrumental in our success.

The achieved peak speed is 3.06 m/s (6.8 mph), with an average speed of 1.95 m/s (4.4 mph). The obtained gait has flight phase that's almost 40% of the gait, with a ground clearance of 3-4 inches.