The Promise of Low Impedance Robotics

Professor Gill A. Pratt

Massachusetts Institute of Technology

AI Lab

Almost all robots, including most humanoid walking robots, embody a "stiffer is better" design and control philosophy inherited from the earliest days of numerically controlled machine tools, where position accuracy in the face of unpredictable force disturbances was of paramount importance. This philosophy is so pervasive that is has become part of the cultural definition of a robot (ask any child to act like a robot and you'll see). By contrast, the impedance of animals (including humans) is low. We cannot hold positions accurately in the face of unexpected force disturbances. What we can do is execute natural tasks, like locomotion, manipulation and prey catching, with breathtaking agility and grace. Thus, for the growing field of autonomous robotics where animal-like behavior is desired, a critical look at the "stiffer is better" design principle is called for.

For several years our laboratory has developed and experimented with a family of low-impedance actuators, mechanisms, and control philosophies that allow our robots and human augmentation devices to interact with the world more softly. In this talk, I will describe our ideas, show videos of our experiments, and talk about future directions of research.

Friday, October 6, 2000

3:30 - 5:00 p.m.

1500 EECS