# Roomba Create 2: how to convert steering angle to radius?

I want to set the steering angle for Roomba Create 2, and as far as I understand I can do this by setting a turning radius for the Roomba Create 2.

My question is:

• How to convert steering angle to turning radius, so that I can set a correct turning radius for a desired steering angle?
• How do you define "steering angle"? Isn't that only for ackerman steering vehicles? I am not sure it is defined for differential drive vehicles such as Create. Why do you need a steering angle?
– Ben
Apr 18, 2019 at 16:31

## 1 Answer

The wheels can't be steered to an angle. All you can do is make one wheel spin faster and then the robot travels along an arc with a given radius

You can place the center of the arc any place you like along a line that connects the two wheels even between the wheels or a few meters to the side or under one wheel. Then if you need to turn to say 30 degrees you drive along the arc for 30 degrees.

To "turn in place" 30 degrees, you place the center of the arc midway between the wheels, rotate, stop then drive straight. Is that what is needed?

• Thanks, these information are very helpful for me. Do you know any link/website where I can find a good tutorial for calculating the arc/arc center/turn angle ? It will be a big help to me.
– Bien
Apr 24, 2019 at 5:51