Drawing of Gears

Mobility of Objects in Space

"Never mistake motion for action." - Ernest Hemingway

Soon I hope to have a tutorial document on this subject illustrated with animation. However, in the mean time you can read about the topic in an early survey paper I wrote or play with the interactive Java applets found on some of the links listed below. You will also find more in-depth material in my papers on the following more specific topics: The research described in the above papers is in fact concerned with the general theory of interlocking polygons in the plane and polyhedra in space. Therefore the analysis and design of interlocking puzzles such as burrs is closely related to local motion planning as well as assembly and disassembly in manufacturing. The literature on burr-puzzles is very helpful for thinking about and visualizing these kinds of geometric problems.

Links to related sites:

Linkages, Rigid and Movable Polygons:

Untangling Polygons and Chains in 2 and 3 Dimensions:

Barbados reading list for (Y2K+2) Workshop:
Additional Reading:

Protein Folding:

Flexing and Unfolding Polyhedra: