Picking a gyro for field-centric swerve control

[Jared Russell]

Three unpowered omniwheels in a "kiwi" configuration (as the sides of an equilateral triangle, e.g. at 120 degree angles to each other).

An encoder on each wheel.

The entire assembly on a suspension to ensure that it never leaves the ground (assuming a flat-ish field).

Such an arrangement would theoretically give you drift-free position and velocity in R2, and would be robust to collision (as long as the wheels don't leave the ground).