I am building a small, electrically powered vehicle that needs to autonomously drive down a straight tiled floor for a distance of 8 -12 meters in 3 seconds with a margin of error at 3 centimeters.
I wanted to use a stepper motor since it is both precise and faster than a continuous servo. But then I wondered if I should use 1 super powerful stepper motor or 4 medium stepper motors on each wheel.
Keep in mind that in a small car unless you accelerate really slowly and the surface is perfect you are probably going to have a fair amount of slip / bounce. I tried a few things like this and found that where i thought the car would be from wheel rotations is not where it ends up. Maybe an encoder on one of the un-driven wheels just measuring ground distance would be more accurate. I don't know, just a thought. Especially if you want to get there fast. 12 meters in three seconds is a fair clip. Just getting up to speed and back again is going to be tricky enough without trying to keep your drive wheels from spinning.