I've worked with Arduino and I agree with WizenedEE. For making a full FRC robot, it is not the way to go. Maybe an FTC robot, which is more like what Arduino can be used for, but even then you will have trouble getting it to communicate with the drivers.
What we are doing is much more higher-end than what Arduino is meant for. If you are going to do this, you will need to make a lot of custom solutions and code and there won't be a lot of help out there.
What WizenedEE was talking about at the end sounded like a good option to look into if you just wanted a driving robot. It would be much less "custom" than working with an Arduino. Here's a video that's related:
http://www.crazybuilders.com/item.ph...roject_section