Preview of Dave's "Monster Truck on Mars"

[JesseK]

Yet another NASAbot with crab drive. I do believe NASA loves crab drive. I wonder what the weight/cost of that thing is and if we can get the drive train in under 75lbs/$3000...

Those wheels look beasty.

[Nate Laverdure]

Originally Posted by JesseK

Yet another NASAbot with crab drive.

To be technical, depending on the situation, the rover can use any of several steering modes at any time: tank drive, crab/swerve drive, Ackerman drive, and probably one I'm forgetting. The steering system is built on a rocker-bogie suspension system, and the whole thing is a derivative of the systems used on both the Mars Pathfinder and Mars Exploration Rover programs.

EDIT: See here for info on the MER drive system.
EDIT 2: Oh yeah, the one I forgot! To add to the list of modes of steering, the rovers also have a pre-programmed turn-in-place routine, as evidenced here.
EDIT 3: Hey, sorry for all the edits, but check out the rover's right front wheel in the picture I just posted. Notice the lettering hidden in the tread? That's clever.

[JesseK]

Thanks for the clarification. I'm surprised we havne't seen a rocker-bogie-type drivetrain in FIRST yet, or at least I haven't in the couple of years I've done FIRST.

edit - Well, maybe now that I think about how much force other robots could impact upon your drive train....maybe I'm not so surprised any more...