[psy_wombats]

I'd recommend a PID for velocity. You'd set up one for each wheel, and then just change the target values every time you needed too, I suppose. Or maybe just for autonomous, as trying to brake wouldn't work...

Anyway, there are a couple of whitepapers on PID you can use, and I know Kevin Watson has PID for velocity already made and ready to go. They work very well if you can use them.