# Calculating angular velocity when given two wheels speed

1. Jun 14, 2015

### Idaan

Hello everyone. I'm new here, though I've been using the site for a long time now. Now, I have a question. =)

Suppose I have a vehicle with 3 wheels, one frontal passive wheel, and two wheels with different motors in the back. How will I go about calculating the angular velocity of the car, if given the velocity of each wheel? Or maybe given the relation between the two said speeds?

Regards,
Idaan.

2. Jun 14, 2015

### Baluncore

Welcome to PF.

You can measure the velocities v1 and v2 of the two wheels.
The velocity of the midpoint between those will be the average. v = (v1 + v2) / 2

Knowing v1, v2, and the (radial) distance between w1 and w2 you can work out the radius of the turn, r, since the ratio v1/r1 = v2/r2 = v/r.

You now know the velocity, v, and radius, r, so you can work out the time to do a one radian turn.
The reciprocal of that is the angular rate.