A Three-Dimensional Passive-Dynamic Walking Robot with Two Legs and Knees (PDF)

Collins, S. H., Wisse, M., Ruina, A.
International Journal of Robotics Research, Vol. 20, No. 2, Pages 607-615, 2001

VIDEO: From Angle Stream on Youtube | downloadable(MPG) (1.6 MB)
VIDEO: From Behind Stream on Youtube | downloadable(MPG) (1.7 MB)

VIDEO: Walking Medley (MOV) (34.8 MB)
In the fall 0f 1998, Martijn Wisse visited the Cornell lab. Inspired by the 1912 Bechstein patent, he built a most remarkable machine.

Kneed Walker, by Martijn Wisse Stream on Youtube | downloadable (MOV) (3.9MB)
In the summer of 2000, undergraduate Steven Collins worked on improving Martijn Wisse's passive walker. The resulting walking device combines four ideas to try to lift kneed 2D passive-dynamic walking to 3 dimensions. The ideas are:
  1. Use wide feet that guide the motion, as per the 1912 Bechstein patent
  2. Use soft heels that kill the instability from indeterminacy at the collision of a line of contact.
  3. Counter-swing the arms to reduce angular momentum effects about the vertical axis, as per the 1888 Fallis patent.
  4. Swing the arms side to side at appropriate times to reduce side-to-side rocking.
We think this robot has as natural looking a steady walking gait as any other robot in the world. Compare, for example to the Honda Humanoid. Let us know of other comparison videos or if you disagree.