Caveat:

If your telescope doors are too (alledgedly) smart and human friendly, you better have an OVERRIDE function when a sensor fails, or when you attempt to close the doors due to precipitation, snow, fog etc.

You need to allow for weather based falsing of the sensors or else your door will be less inclined to close when you are most inclined to close them.

It wouldn't be as much fun, but you could simply sound a warning alarm 20 seconds before firing the motors to close the door. Not so loud that someone couldn't yell to halt it in case they were doing door maintenance.

(PLCs are not much fun)

aka j