I recently came accross the suspension of the latest Mars rover Curiosity:
It uses a Rocker-Bogie suspension, very cool. I didn't understand how exactly this keeps the robot level at first, until I found some more info and this model (and others):
The "trick" is that both rockers (the large frames/bows) are connected through a differential. Anyway, of course this has been done with LEGO and Mindstorms before. I'll let you google and look on youtube yourself, but two really cool videos of an NXT bot:
And last vid: The real rover (model of the suspension system) in action: .
RWTH - Mindstorms NXT Toolbox for MATLAB state of the art in nxt remote control programming http://www.mindstorms.rwth-aachen.de MotorControl now also in Python, .net, and Mathematica
I haven't checked out Mindboards for quite a while and I'm glad I did. It's an amazing coincidence that I've been working on the same project.
My Mars Rotacaster Rover uses my favourite wheels, the amazing Rotacaster Omni-wheels for unsurpassed manoeuvrability in confined spaces.
I've had a few attempts, going back to the days of my LEGO Mindstorms RCX Kit to build a working Mars Rover that had the same suspension system. They all failed for various reasons, including steering the front and rear powered wheels. Also I was probably making the whole drive-train far too complicated, which introduced lots of reliability issues.
The project is still evolving, with the removal of the 'Shock Absorber" Supports to the chassis. I now use a Hitechnic Acceleration Sensor in conjunction with an NXT Motor to make the chassis self levelling, independent of the 'Rocker-Bogie' inclination...
I built a model of the Sojourner a couple months ago. It was almost the same size as the real one. Ultimately, it failed due to high weight, structural integrity, and wheel availability. I will be posting it here and on Brickshelf soon.
A.K.A. NeXT-Generation. "A kingdom of heaven for RobotC now has recursion!"