help on open&close doors w/ comparators

we are having a project on elevator.. now we decided to put the dc motor on each floor so that when the elevator reaches the desired floor the door automatiaclly opens..

please give a link or any suggest on how to biuld the circuit..

also with weight sensors, if the elevators exceeds its weight limit the door would not close and the levator would not start.. so thier should be a comparator crcuit.. how can we design it???

tnx for your help...

up2x.. please giv me ideas for our prcjt..Y_Y

Part of your problem is you want something fairly open ended. As a retrofit you're options are pretty limited. For example, many cases the motors themselves sense the weight, but this is part of the initial design. Would you be happy to install a false floor with strain gages underneith? It would be heavy in its own right.

Basically this is why they pay engineers big bucks.