Chebyshev Walking Machine

Chebyshev's walking machine is based on the four-bar linkage bearing his name.

This linkage is a crank-rocker mechanism with a ground bar of length , a crank of length , a rocker of length 1, and a coupler of length 2. With this geometry, in the lower part of its path the endpoint of the linkage follows a quasi-rectilinear motion with almost constant speed [1].