Team 1640 did swerve this year and as a off season project the math for 4 wheel independent steering and drive was worked out. There are several resources on our web site on this subject. On this page at the bottom are links to the math models.
http://wiki.team1640.com/index.php?t...el_Pivot_Drive
On this page there are more info on our pivots.
http://wiki.team1640.com/index.php?t...VI_Drive_Train
The website is a WIKI so the info is there, it does take a little searching to find everything we have on crab. This is the crab with a twist white paper.
http://wiki.team1640.com/images/3/3a...Twist_edit.pdf