"How does it drive?!?!" Team 857's bot

[Adam Krajewski]

To drive at a linear velocity V in the direction of theta from any vector starting at the reference point Xref, Yref with an angular velocity around Xref, Yref of psi, the wheels (radius of R, and length L1, L2, and L3 from Xref, Yref) must have a rotational velocity of w1, w2, w3.

w1 = (|V|/2R)*(sin theta - sqr(3)*cos theta)+(psi*L1/R)
w2 = -(|V|/R)*(sin theta)+(psi*L2/R)
w3 = (|V|/2R)*(sin theta + sqr(3)*cos theta)+(psi*L3/R)

Just calculate those and you can drive in any direction you want, while spinning, including "straight". The omnidirectional holonomic nature really creates no "front" or "back". We arbitrarily chose those sides. In the case of the prototype drive, the 'front' was perpendicular to the wheel driven by the Fisher Price motor.

Adam