Load sensing switch/relay?

Hello everyone, I'm working on a small project and was hoping for some help. I've designed an apparatus that uses a 12v dc motor to open and close a sliding door so our dog can come and go as he pleases. It will be triggered by a proximity sensor that starts the motor and cycles the apparatus to open and close the door. I am looking for a switch or relay that would sense the motors (increased) load in case the dog or something else is obstructing the door while it's closing - sort of a safety feature. It would then reverse the motor and slide the door back open. Is there such a switch or relay? I would assume that it's sensitivity would have to be adjustable. Thanks.

A high-side current monitor, like a Zetex ZXCT1009 or one of its brothers, hooked to a comparator, like an LM339, could be used to trip a relay.

It's often easier to monitor the low side current coming back from the reversing device. It's also usually necessary to ignore current for a short time after the motor has started, as the current peaks there as well.

Here is some code that I am running on electric car windows. There is a sensing resistor in the connection to the sources of the N-Mosfets in the bridge.

The code also contains the switch sensing, which uses the ADCs as I ran out of connections. There is also communication to the identical unit on the other side of the car.

another way you can use a mechanical torque switch or a similar linear switch for force (spring loaded to adjust the sensitivity)

The OP already solved this problem in another thread. https://www.electro-tech-online.com/threads/simple-delay-for-a-relay.113453/

Ken