4-Wheel (current) VS Rocker Bogie
6-Wheel Rocker Bogie Design
Pros:
- less ground pressure
- requires less friction
- better cornering
- better at handling uneven terrain
- minimize drag and reduce lift
- better safety (if one tire blows, less likely to lose control)
- increased stopping power
- less unsprung weight
- lower profile of front wheels (more aerodynamic)
- Climbs large obstacles (compared to wheel size) with all wheels in contact with floor (works at slow speeds)
- Rocking of the rover body is the average of the side movements.
- Less susceptible to side tipping
- No springs needed
- Equal force distribution on wheels.
- Extensive documentation
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- heavier
- more complicated steering, drivetrain, suspension
- Requires 1 motor per wheel
- Unstable at high speeds (damage to arms, suspension speed) and less effective traction.
4-Wheel Design
Pros:
- lighter
- simpler design
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- (pretty much all the Rocker Bogie Pros)
Specifics to Optimize (for either design):
- Minimize Weight
- Maximize torque and speed
- Maximize Strength
- Maximize ground clearance
- Minimize Maintenance complexity
Resources for bogie and 4-wheel
- https://docs.google.com/document/d/15E-aOWeHoS8cvI4AzRLjRI6-QUYpROUitrw6f02qD-0/edit?usp=sharing
- https://docs.google.com/document/d/1UcJNQXd8H05f_Skjxgq6LE_oodsz338FhATCdz2LR2U/edit?usp=sharing
- https://docs.google.com/document/d/1Mo-QHTKMeQfpWPPqY7LaBXobAnIGRZKNITPA0xrfvz4/edit?usp=sharing
- https://www.moogparts.com/parts-matter/all-about-hub-assemblies.html
- https://www.quora.com/What-is-the-difference-between-a-four-wheeled-and-a-six-wheeled-all-terrain-robot
- https://mars.nasa.gov/mer/mission/rover/wheels-and-legs/
- https://www.academia.edu/8190529/Dynamic_Rocker-Bogie_A_Stability_Enhancement_for_High-Speed_Traversal
- http://esmats.eu/amspapers/pastpapers/pdfs/2004/harrington.pdf
- https://docs.google.com/spreadsheets/d/1aPZzbNhaItw5g7w2JWuhTyHp2mWS-Gx1Cxe82eSvbjU/edit#gid=0
- https://www.engineeringtoolbox.com/area-moment-inertia-d_1328.html
- https://www.continuummechanics.org/columnbuckling.html
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