Chebyshev's Lambda Mechanism
The Chebyshev's Lambda Mechanism[1] is a four-bar mechanism that converts rotational motion to approximate straight-line motion with approximate constant velocity.[2] 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.[3]
The example to the right spends over half of the cycle in the near straight portion. Coupler point stays within 1% positional tolerance with intersecting the ideal straight line 6 times.
The Chebyshev's Lambda Mechanism is a cognate linkage of the Chebyshev linkage.
The linkage was first shown in Paris on the Exposition Universelle (1878) as "The Plantigrade Machine".[4][5]
The Chebyshev's Lambda Mechanism looks like the Greek letter lambda, therefore the linkage is also known as Lambda Mechanism.[6]
Chebyshev's Lambda Mechanism used in vehicle suspension mechanisms, walking robots and rover wheel mechanisms. In 2004, a study completed as a Master of Science Thesis at Izmir Institute of Technology, a new mechanism design introduced by combining two symmetrical Lambda Mechanism to distribute the force evenly on to ground with providing the straight vertical wheel motion.[7]
Double Lambda Chebyshev Mechanism rover suspension design manufactured and tested in Earth Rover Project of Los Angeles City College Electronics Club[8]
See also
References
- http://demonstrations.wolfram.com/ChebyshevsLambdaMechanism/
- Design of Machinery. 2011.
- DOM p134 Hoecken linkage (PDF).
- http://mech.spbstu.ru/Dzenushko_Dainis:_Walking_mechanisms_survey#The_Chebyshev_Walking_Mechanism
- "Archived copy". Archived from the original on 2014-11-29. Retrieved 2014-11-16.CS1 maint: archived copy as title (link)
- "Archived copy". Archived from the original on 2014-11-29. Retrieved 2014-11-16.CS1 maint: archived copy as title (link)
- https://openaccess.iyte.edu.tr/handle/11147/3449 Design of A Mars Rover Suspension Mechanism
- https://vimeo.com/117774490 Video of The Earth Rover Moxie
External links
Wikimedia Commons has media related to Chebyshev's Lambda Mechanism. |
- Hoeckens approximate straight-line mechanism (diagram and table of lengths)
- Hoeckens straight line linkage (Homemade example)
- Video of computer simulation of Tchebychev walking machine (Стопоход Чебышева).
- alexdenouden.nl - Rectilinear motion after "Tchebychev"
- A simulation using the Molecular Workbench software
- How does a Hoecken's Linkage Work? (Interactive Flash Animation)