Arduino Uno Programming For A Wheelchair Lift

I have a wheelchair lift that is controlled by 4 relays with 2 potentiometers for position feedback. 2 relays control the up/down motion of the lift with 1 pot for height feedback. The other two relays control actuators for a shroud that will raise/lower so the wheelchair doesn't roll off, the other pot is attached to the shroud for feedback This lift will have 3 preset positions; Position 1 will be all the way down for wheelchair loading/unloading Position 2 will be at a mid point to act as a dumb step Position 3 will be at the top for wheelchair loading/unloading There needs to be a Stop button on an interrupt to set all relays low When the lift goes between Position 1 and 3 the shroud will need to raise before the lift starts to raise or lower. When the lift goes to Position 2 the shroud must be down