Chebyshev lambda linkage

[3] The precise design trades off straightness, lack of acceleration, and the proportion of the driving rotation that is spent in the linear portion of the full curve.

The coupler (link 3) point stays within 1% positional tolerance while intersecting the ideal straight line 6 times.

The linkage was first shown in Paris on the Exposition Universelle (1878) as "The Plantigrade Machine".

In 2004, a study completed as a Master of Science Thesis at Izmir Institute of Technology introduced a new mechanism design by combining two symmetrical Lambda linkages to distribute the force evenly on to ground with providing the straight vertical wheel motion.

[6] It was then designed, manufactured, and tested in the Earth Rover Project of Los Angeles City College Electronics Club.

Animation of the Chebyshev Lambda Linkage
Dimensions (unit length a ):
Link 2: a
Link 4: 2.5 a
Link 3: 2.5 a + 2.5 a
Link 1 (horizontal distance between ground joints): 2 a
Chebyshev's plantigrade machine.
A Chebyshev Translating Table Linkage, which combines together two cognate linkages : the Chebyshev Linkage and Chebyshev Lambda Linkage.