Connect with us

Sensor to activate a handicap door switch

Discussion in 'Sensors and Actuators' started by pbesong, Aug 8, 2018.

  1. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    I would like to make a sensor of some sort that will only operate the handicap door switch if the person holding some type of sending unit comes in proximity of the switch, but that they would not have to push a button. It should open only for them and only when it comes within 3 feet or so of the door. Is this possible? I have seen the switch that operates the handicap door and am including a photo. I'm guessing what I make would temporarily bridge the circuit (bypassing the already-installed switch) to engage the door's actuator. What would I need to make something like this? Here is a photo of the switch on the wall. I'm thinking my switch would just connect to the pigtails to complete the circuit when activated. If it helps any, the switch in the photo is 15A, 125/250VAC.
     

    Attached Files:

    Last edited: Aug 8, 2018
  2. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    Sounds like a Rfid sensor may fit the bill.
     
  3. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    that sounds exactly like what I need. thanks!
     
  4. hevans1944

    hevans1944 Hop - AC8NS

    3,911
    1,867
    Jun 21, 2012
    Most RFID sensors have a very short range, typically only about an inch or so, nowhere near the 3 feet that @pbesong requested. They are also way overkill for this application in requiring some sort of computer interface, typically an Arduino or Raspberry Pi.

    Consider instead a wireless key fob remote relay to activate the door switch in parallel with the existing door activation switch. Unfortunately, all of the key fob device that I am aware of require the user to push a button on the fob.
     
  5. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    The tag could be put at bottom of chair and the sensor installed in floor provided they pass through a narrow path.

    Or, opt for long range rfid sensors.
    Check this out:


    A economical way could be to use a "loop sensor" in floor like they do for vehicle detection. Problem with that is, the different construction of wheelchairs could present a sensitivity problem if they are drastically different. Eg: Steel vs Aluminum vs Hdpe plastic
     
    pbesong likes this.
  6. Bluejets

    Bluejets

    2,981
    578
    Oct 5, 2014
    Hospital egress systems we used to install were relatively long range, 3 metres if I remember correctly.
    Patient to be monitored would wear a wrist band, and the alarm system transcievers were placed either side of any required door way. One unit, inner, was on the wall around 2.2 metres and the external sensor on the exterior ceiling at around 3.0 metres.
    Approaching the door would raise an alert at the nurse station and detection outside the doorway would bring up an "escaped" alarm.
     
    pbesong likes this.
  7. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    That'd work too, but the downside of a Rf transmitter would be quickly exhausted batteries. (Always transmitting)
    What would work best comes down to budget and the number of wheelchairs that would use it. If only a few people need it the transceiver might be the way to go, but If there's 50 or more people using the handicap door, Rfid might make more sense because tags only cost about 15 cents a piece.
     
  8. pbesong

    pbesong

    10
    0
    Aug 8, 2018
     
  9. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    I was actually thinking of attaching the tag on a Beam robot, which looks like an iPad that can be driven on wheels over the internet. I wanted to just install the tag on the Beam and it would open the door automatically so it would not require a person to accompany the robot.
     
  10. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    Wow, high tech. The tag would need to be on the wheelchair somewhere and the sensor could be on the robot.
    I don't know much about long range rfid but I'd imagine it could get pricey.
     
  11. pbesong

    pbesong

    10
    0
    Aug 8, 2018
     
  12. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    Here are the robots we use for distance education: https://suitabletech.com
    The drawback with them is that they cannot open doors, go up stairs, or use elevators. They require an assistant on location.
     
  13. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    I guess I don't understand the application.
    If the beam robot is controlled by internet to greet handicap person, why not just just open door via internet?
     
  14. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    There is no handicapped person per se. Controlling the door via internet would not be built in to the Beam s/w. The Beam robot is being used by a student (not necessarily handicapped) who is attending the location (conference or classes) virtually. Being able to open the door via RFID would be seamless and require no separate s/w or the need to press a button.
     
  15. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    So the intent is to have the door open just for the robot or do you want it for handicap personnel also?
     
  16. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    right now this is just for the robot, but it could possibly be extended to the handicapped as well.
     
  17. Bluejets

    Bluejets

    2,981
    578
    Oct 5, 2014
    No battery........wall unit is active component and is mains powered.
     
  18. pbesong

    pbesong

    10
    0
    Aug 8, 2018
    right.
     
  19. Tha fios agaibh

    Tha fios agaibh

    1,765
    575
    Aug 11, 2014
    If you just want it to open for the robot, bluejets transceiver idea would probably be the simplest, although I'm still imaging the transmitter mounted on the robot would be battery powered.
    If you wanted to add numerous wheelchairs later, of course you'd have to add transmitters that require battery power.
    The beauty of Rfid is they don't require batteries.
     
  20. hevans1944

    hevans1944 Hop - AC8NS

    3,911
    1,867
    Jun 21, 2012
    It would appear that "handicapped" and "wheelchairs" are Red Herrings. The real application is an "add on" means to remotely operate powered doors when approached by the Beam virtual reality "robots" as they wheel about from one location to another. It would probably be a dynamite app if they could operate elevators too. Since the Beam software is proprietary, this "add on" would have to operate seamlessly and independently of the Beam robot's movements.

    Some modification of the infrastructure, perhaps extensive modification, where the Beam robots are intended to operate will be required. Most learning facilities that accept public participation must offer handicapped access, which generally means powered doors operated by palm switches. The OP intimated that an acceptable "solution" would be to parallel the palm switches with some sort of RF device that communicated with, and actuated relay contacts under command of, something located on the Beam robot. Thus, the Beam robot would simply approach a door and the door would open. Easy, peasy. Just add money. Passive RFID tags would be up to the task.
     
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.