Selection on indoor target localization

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Xiao
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Posted by Xiao: Wed. Mar 30, 2022 - 02:21 AM
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It is well known that you can't locate target based on GPS indoor, we need to use other technology to finish it.

For data transfering is a basic requirement for most of IT system, it is the best way to realize both functions on same hardware: communication & localization.

I used LoRa to communication before, it is cheap enough, and the communication range is long enough too。

It said we can locate target through LoRa technology, I did not study it yet.

Is there any simple way to locate indoor target with accuracy of 1 meter.

This is what I cared:

1) not expensive;

2) with current product, mass products better;

3) open source better;

4) running projet/application exist .

 

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Learning and Information, General Electronics, Bluetooth
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avrcandies
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Posted by avrcandies: Wed. Mar 30, 2022 - 03:01 AM
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Our dept developed an indoor system using lasers to read barcoded targets from long distances for positioning...it worked quite well, but at the time was a bit ambitious for the market. It was originated by a research organization from overseas.

https://www.iaarc.org/publicatio...

Since then, there are chips that can measure time of flight to targets for positioning very accurately.  If you know 3 or more distinct distances, you can find your location without ambiguity, 2 is the minimum with potential ambiguity.

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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N.Winterbottom
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Posted by N.Winterbottom: Wed. Mar 30, 2022 - 07:45 AM
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I've seen a demo of Indoor positioning using Bluetooth 4.0 low energy. The performance was only fair and to an extent needed to learn the room. There was mus-positioning when people moved about the room, but when seated become usable again.

 

As a demo the performance was good enough for future research. This indeed has happened to create a Bluetooth 5.1 Indoor Positioning Platform.

 

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avrcandies
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Posted by avrcandies: Wed. Mar 30, 2022 - 08:48 AM
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It is well known that you can't locate target based on GPS indoor

Actually this is not clear. what do you mean by target and locate?  item?

Do you want to find out where a target is located (you are at the target & want to know its location relative to the room or other coordinates)?

Or, The target is lost and you want to know where it is?

 

There were some "kid finders" that used a directional antenna & signal strength method that could quickly direct you towards a lost kid (who was wearing a transponder).

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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Xiao
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Posted by Xiao: Thu. Mar 31, 2022 - 07:17 AM (Reply to #4)
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Do you know CS game?

I want to show the position of each player on screen in my game.

Basically same with GPS navigating with mobile phone, but, my client has no such process ability to do complex computing.

So,the ideal way is :

.client send out signal periodly;

.devices like WIFI AP receive the signal and forward to server;

.server compute the signals received and locate the client.

 

The WiFi devices is one of the most used product and we can get cheap or expensive product as we like, what the only problem is the communication range is not so far.

 

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avrcandies
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Posted by avrcandies: Thu. Mar 31, 2022 - 07:58 AM
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.server compute the signals received and locate the client.

You need to give a lot more details.  Why do you think this will give location?  One signal strength is not enough (forms an arc)...maybe if you have several you can triangulate.

In any case, wifi is trying to go far, so the RSSI tends to fall off slowly once you get to a certain distance (meaning it gets harder & harder to say how far it is).

Do you have any of your own measurements?

It said we can locate target through LoRa technology, I did not study it yet.

 

WHAT said? Why do you leave out such important details?

 

    

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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Brian Fairchild
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Posted by Brian Fairchild: Thu. Mar 31, 2022 - 08:03 AM
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Xiao wrote:

Is there any simple way to locate indoor target with accuracy of 1 meter.

 

Let's start with a few details (I'm sure there are more but)...

 

1) In the same room or the same building?

2) If room, how big?

3) If room, empty or with obstacles?

4) If room, can you place 'transmitters' in the room?

5) What update rate?

#1 Hardware Problem? https://www.avrfreaks.net/forum/...

#2 Hardware Problem? Read AVR042.

#3 All grounds are not created equal

#4 Have you proved your chip is running at xxMHz?

#5 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand."

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Gold Markclawson
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Posted by clawson: Thu. Mar 31, 2022 - 08:50 AM
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Xiao wrote:
It is well known that you can't locate target based on GPS indoor,
Is that true even for DGPS?

 

Actually:

 

https://research.sabanciuniv.edu...

 

which proposes:

 

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gchapman
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Posted by gchapman: Thu. Mar 31, 2022 - 02:29 PM (Reply to #8)
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GNSS repeaters are effective though don't know the price and cost.

 

GNSS has an ionospheric adjustment though there's an issue especially for the current solar cycle (solar flares heat the atmosphere [X-rays], CME plasma "bends" the ionosphere a day or few after the flare)

South Atlantic Anomaly is growing in size and intensity due to reduction in Earth's magnetic field strength (Van Allen belt energetic electrons affect satellites); at least one solar flare in this cycle (January'22?) did lead to a significant EM storm and the resultant excessive telluric currents (solar energetic protons, via Interplanetary Magnetic Field into Earth's poles though IIRC also in a CME)

IDK what solar flare X level will begin to significantly disable GNSS (disable is worse than degrade); pilots/aviators can compensate for GNSS malfunction.

 

Second the Bluetooth motion.

Selection on indoor target localization | AVR Freaks

 

"Dare to be naïve." - Buckminster Fuller

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ki0bk
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Posted by ki0bk: Thu. Mar 31, 2022 - 03:02 PM
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FF = PI > S.E.T

 

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Xiao
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Posted by Xiao: Fri. Apr 1, 2022 - 02:16 AM (Reply to #8)
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I heard that before, but not think it seriously for the price, I think it will not be cheap.

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Xiao
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Posted by Xiao: Fri. Apr 1, 2022 - 02:43 AM (Reply to #7)
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1) In the same room or the same building? --> same room or building in most case, including multi layers.

2) If room, how big?  --> 1000 square meters at least

3) If room, empty or with obstacles? --> will deploy objects(plastic products，maybe) or wall exist

4) If room, can you place 'transmitters' in the room?  -->no other way,I think.

5) What update rate? --> few Kbytes is enough

 

Possible of WiFi technology:

1) not expensive for client modules and AP;

    but, the alogrithm could be diffcult if the consistency & stability of APs is not good, so, the price will rise in order to improve consistency & stability.

2) the total cost could be acceptable;

    200 square meter/AP,  1000 square meter / 200 (square meter/AP) = 5 AP

3) the research & application on WiFi postion are very extensive.

 

 

 

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avrcandies
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Posted by avrcandies: Fri. Apr 1, 2022 - 02:54 AM
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5) What update rate? --> few Kbytes is enough  

Take a look again...1 time a minute, 5 times a minute,  2 times a second?  what rate? 

 

3) the research & application on WiFi postion are very extensive.

What exactly are you talking about (what facts are you referring to)??

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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Gold Markclawson
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Posted by clawson: Fri. Apr 1, 2022 - 08:47 AM
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Xiao wrote:
I think it will not be cheap.
Define cheap?

 

Alternatively, another approach might not be radio positioning but LIDAR so the device itself can map out its environment and determine where it is by "looking around". You can get small LIDAR for a few hundred bucks:

 

https://coolcomponents.co.uk/sea...

 

(you'd probably want one 360 device).

 

Of course it will also take a bit of on-board processing to process the environment map in realtime but something like an Rpi should be up to that challenge. It will help to position some recognizable objects in the world for such a solution to work.

 

A cheaper form of the same idea is multiple IR beacons positioned around the room then detectors and intelligence on the target to determine where it is in relation to each beacon it can "see".

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gchapman
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Posted by gchapman: Fri. Apr 1, 2022 - 12:51 PM (Reply to #14)
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clawson wrote:
... multiple IR beacons ...
Likewise Bluetooth beacons with a precision of 3% for the use case.

https://www.bluetooth.com/bluetooth-resources/?tags=beacons

 

"Dare to be naïve." - Buckminster Fuller

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mauro gontarski
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Posted by mauro gontarski: Mon. Apr 11, 2022 - 02:31 PM
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UWB is very accurate.

 

https://www.qorvo.com/products/p...

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Jeckson
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Posted by Jeckson: Thu. Apr 21, 2022 - 09:20 AM
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gchapman wrote:
Likewise Bluetooth beacons with a precision of 3% for the use case.

 

https://www.bluetooth.com/bluetooth-resources/?tags=beacons

 yes.Since the OP at China,Look at Alibaba,Banggood or AliExpress for buetooth locator,very cheap.

www.tokopedia.com/madagang .Buy and Donated cheap electronics and manuscripts.

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Xiao
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Posted by Xiao: Sun. Jun 19, 2022 - 02:44 AM (Reply to #17)
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How about the distance?  It seems to me that the distance is within a few meters.

 

[update]

The distance could be tens meters, but the precision is many meters.

 

Maybe UWB is the choice, precision can reach 1.x meters, that is OK, but the price is not OK :) 

 

Last Edited: Sun. Jun 19, 2022 - 03:48 AM
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HKPhysicist
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Posted by HKPhysicist: Fri. Jul 1, 2022 - 05:32 PM
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Bluetooth mesh good enough, that is, Bluetooth v5.

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HKPhysicist
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Posted by HKPhysicist: Fri. Jul 1, 2022 - 05:36 PM
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clawson wrote:

Xiao wrote:
It is well known that you can't locate target based on GPS indoor,
Is that true even for DGPS?

 

Actually:

 

https://research.sabanciuniv.edu...

 

which proposes:

 

 

We call this - Appending legs to a snake.

 

You can simply look for another animal with native legs.

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