Fast Line-Follower Motor Selection? What to Look For...

[richardv2]

I want to build a fast line-follower. From details I seen through Google, it looks like 1 meter per second is atainable with the right hardware and software. My questions...

How do I equate 1 meter per second with a specific motor? I know the math is easy - wheel circumference times RPM can give me that - right? Do I plan for a speed of 1-1/2 meters per second so the motor still has some acceleration for the straight-away?

Now, if I want the least mass possible (more mass = harder to get through a turn fast), then do I want the lightest motor that will give me the RPM I need?

And what about torque? How does that figure in? For a given size/motor weight, does double the torque mean I can increase speed faster? Or does more torque mean more weight? ...Or just that from a standstill, higher torque will get me started faster, or what? What would be the trade-off questions I'd ask to select from several torque/speed possibilities?

I plan to use PWM and have a PIC18F control left and right motor speed. I'd start slow and work up speed and add PID as I learn how to apply it.