Tracking a person with RFID or similar tech

[blacksmith]

Hi

Let me start off by saying, that I am a complete noob when it comes to electronics. I am a software developer by day and geek by night, but electronics is not my field by any means. I hope I am on topic here, as I found the forum by googling for forums about RFID.
more: **broken link removed**
My stepdaughter has a very severe degree of autism, and is unable to take care of herself. On several occasions, she has managed to run away from us or her schools/institutions, and it has taken us up to 3 hours of intense search + police help to locate her again. All kinds of bad things can happen to her while she is gone.

I want to be able to track her easily, if she runs away. Now here is my idea - it might be utterly useless or impossible - but it will get you an idea about, what I am looking to achieve.
more: biệt thự athens kim giang
I am thinking, we give her a bracelet with some kind of transmitter (RFID?) that has a range of at least 3-400m, that she cannot take of (that means waterproof is a must). Then as soon as we find out, that she has run away, we get out a receiver/tracker of some sort - and we would be able to cover the entire area she might be in within 20 minutes in a car. As soon as we pick up her signal, we should then be able to pinpoint her location by some sort of directional tracking (not sure if that is the correct term).

Is something like that possible? What would it require? Am I overlooking a much better idea?

Real time gps tracking would be perfect, but I think the issues of battery life + size rules that out. Am I wrong?
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I hope for your assistance and advice.

Thanks in advance

 

[misterT]

You can't build that kind of system with RFID technology. Just google "GPS tracker for kids".

 

[MikeMl]

These kind of trackers look good on TV, but the realities of radio wave propagation, Battery Life, Physical size, transmit antenna efficiency, transmitter power, receiver sensitivity, legality of using the radio spectrum, get in the way of making a practical device.

 

[tcmtech]

Someone recently told me that there are some smart watch/smart pendant devices for kids, disabled people or even animals that do live GPS tracking by reporting their positions at programed intervals to a mapping app you can have on your cell phone or computer.

Run time between recharging is something like 8 - 48+ hours depending on how often it has to power up and report it's position.

That's all I know on the subject.

 

[unclejed613]

there are cell phone apps for that also, especially if your carrier has "family plan" options.

 

[MikeMl]

there are cell phone apps for that also, especially if your carrier has "family plan" options.

What happens is the subject wants to get lost, and ditches the phone?

 

[unclejed613]

that's going to be a problem with anything that they carry...

 

[MikeMl]

...I am thinking, we give her a bracelet with some kind of transmitter (RFID?) that has a range of at least 3-400m, that she cannot take of (that means waterproof is a must). ....

 

[ChrisP58]

A friend of mine has something like this for her daughter.
https://www.amazon.com/Birthday-Tou...ons&keywords=gps+tracker+watch+for+kids&psc=1

There are other sources as well.

Be aware, it uses GPS to know where it is, but uses a cellular network to report that location to you. So in addition to the initial purchase price, there is also a monthly fee.

 

[Diver300]

Be aware, it uses GPS to know where it is, but uses a cellular network to report that location to you. So in addition to the initial purchase price, there is also a monthly fee.

With Pay As You Go in the UK, there's no monthly fee. If you are only sending position information and no videos, and your provider charges for the data sent, the cost is small. The tracking units on my family's cars cost use around 50p of credit per year for each vehicle.

 

[gophert]

Hi

Let me start off by saying, that I am a complete noob when it comes to electronics. I am a software developer by day and geek by night, but electronics is not my field by any means. I hope I am on topic here, as I found the forum by googling for forums about RFID.

My stepdaughter has a very severe degree of autism, and is unable to take care of herself. On several occasions, she has managed to run away from us or her schools/institutions, and it has taken us up to 3 hours of intense search + police help to locate her again. All kinds of bad things can happen to her while she is gone.

I want to be able to track her easily, if she runs away. Now here is my idea - it might be utterly useless or impossible - but it will get you an idea about, what I am looking to achieve.

I am thinking, we give her a bracelet with some kind of transmitter (RFID?) that has a range of at least 3-400m, that she cannot take of (that means waterproof is a must). Then as soon as we find out, that she has run away, we get out a receiver/tracker of some sort - and we would be able to cover the entire area she might be in within 20 minutes in a car. As soon as we pick up her signal, we should then be able to pinpoint her location by some sort of directional tracking (not sure if that is the correct term).

Is something like that possible? What would it require? Am I overlooking a much better idea?

Real time gps tracking would be perfect, but I think the issues of battery life + size rules that out. Am I wrong?

I hope for your assistance and advice.

Thanks in advance

RFID needs a "reader". The reader of tags with a battery can reach several hundred feet in a closed space like a warehouse. That's it for current devices.

There are animal tracking systems that work on a system similar to RFID in that a "reader" sends a signal at a particular frequency to turn on the tracker, then the tracker determines the current GPS coordinates and sends back the current location. The battery life is surprisingly long because it only checks for an incoming signal for a few seconds every few minutes to hours or days (depending on the resolution the project needs).

Products already exist
(angleSense with GPS and monthly subscription) $40/mo
Specifically designed for autistic kids.
https://www.angelsense.com/autism-t...QugAoJS1bkJBea2-2GSbQphJToEPEGkhoCKJcQAvD_BwE


This one from Target
$40 for a one-time purchase and battery lasts about a year - signals when child is out of range (~100ft).
No GPS, just alerts a smart phone app when the child is too far from the guardian's phone.
It includes a child-proof bracelet so the kid cannot take it off.
**broken link removed**

Many more options exist.

 

[unclejed613]

also, many RFID devices use a "passive reflective" system to send data. this requires close proximity to the reader. the tag itself doesn't actually transmit, but modulates the antenna impedance which changes the field strength of the reflected signal.