Broad Area Colloquium For AI-Geometry-Graphics-Robotics-Vision

Low Impedance Robotics

Gill A. Pratt
MIT Leg Lab / AI Lab

Monday, Oct 30, 2000, 4:15PM
TCseq200, Lecture Hall A


Almost all robots, including current 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 walk like a robot and you'll see). By contrast, the impedance of animals (including humans) is low. We cannot hold positions very 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. Previous work by McGeer and others has shown that the passive dynamics of an animal's body acts to self-stabilize and automatically sequence some movements. Unfortunately, in today's stiff, trajectory controlled robots, such natural dynamics are over-ridden.

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 - more like animals. This talk will describe our ideas, show videos of our experiments, and talk about future directions of research.

About the Speaker

Gill A. Pratt is an Assistant Professor at the Massachusetts Institute of Technology and co-directs the MIT Leg Laboratory. He received his Bachelor's, Master's, and Ph.D. Degrees from MIT from the department of Electrical Engineering and Computer Science in 1983, 1987, and 1989, respectively.
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Last modified: Wed Oct 25 15:05:21 PST 2000