I have a rail cart moving for 20m on two rails that are 6 meters wide.
I was thinking to use two stepper motor with closed loop like this
In this way is easy to move them at the same time of the same quantity to avoid that the cart warps and get an alarm if one motor fails. At start the cart goes home and, with two proximity sensors, one per rail, it can perform a fine setup, moving one motor per time, to stay perfectly aligned.
I'm wondering if you have suggestions or comments about this solution.