[steven114]

If you want to measure the max speed in feet/s or m/s, you will need a way to measure the robot's speed. Trial and error - use the code to assign one value to the speed controllers, and measure the actual speed. Then limit the speed controller to the closest value that you want. If you want some sort of more advanced, much more reliable, and all-around better solution, experiment with some sort of encoder - either the hall effect sensors or maybe an optical encoder to read actual speed off the drive system.