Hello everyone, I am trying to perform an indoor geolocation through TDOA algorithms. Explaining its operation a little, it is about calculating the difference in arrival time at each anchor or base node. The idea is to place 4 stations or nodes that emit an RF signal synchronously and that an arduino detects this signal and responds, the response of this arduino has to reach the 4 stations at a different time x in the 4. The problem o The difficulty of this method is that the stations must have a precise synchrony in the internal clocks, in addition to being able to process the information in nanoseconds, since the propagation time of signals indoors has this order.
As can be seen, the arduino that responds does not enter the equation, so it does not concern me, it is enough that it has a reception module to capture the signal and a transmitter.
My doubt arises in the base stations, do you know any Arduino or micro that works at these clock frequencies?
All this is to be done through WiFi signals, so the signal frequency is 2.4 GHz.
I have an arduino with the WiFiNINA module and I tried the RSSI method, but this method hardly provides sensitivity, it has too many errors. I tried to ping that arduino that is the MKR1010 or the Arduino Uno Rev 2 and they gave me values of milliseconds, this does not help me since the propagation time is nanoseconds, everything else is processing time that induces a Quite a big mistake, if I knew the processing time I could subtract it and get the order of the nanoseconds, the problem is that it gives me integer values of ms so it doesn't work for me either. As you can see I'm a bit stuck on this topic, I've thought of using something like rock pi s, but here comes the topic of programming in operating systems and it escapes me a bit, although it could be a viable option.
Another topic is how to synchronize the internal clocks once the hardware has been chosen, if you have any ideas about this topic I would appreciate it.
Have you been able to find any examples of what you have decribed ?
I suspect not, so why do you think that is so, since indoor location is a very common requirement ?
The only thing like this that I have seen working used ir lasers scanned using oscillating or rotating mirrors. At least 2 "lighthouses" are set up at points in the room. I understand they work like this: Each lighthouse sends out an IR flash in all directions as each scan begins. The receiver detects this pulse and then measures the delay until the IR scan is detected. Knowing the scan speed of the mirror, the angle from the receiver to the lighthouse can be calculated. Do this with a second lighthouse, and the angles can be used to triangulate the receiver's position.
Maybe study sytems like this;
or this;
The problem is that i want to use WiFi not UWB. For Wi-Fi location there are three indicators that can be used:
- RSSI Power
- Time of arrival
- Time difference of arrival
Power is useless because it is a very fluctuating value. With respect to the other two, they are more robust values so they should work better.
What I am doing is a project that does not have examples or I have not found them, since they either use UWB or BLE, however these technologies need to place too many nodes every few meters, which multiplies the cost.
This is why I want to carry out a study to see if I can position it indoors. The problem is that I need hardware to be able to ping and receive a pong in a matter of nanoseconds, calculate the time difference between the anchors and apply the algorithm. That is why the anchors must also be synchronized.
I have looked at things like this, some have wifi modules and the processors have frequencies from 1.5GHz so it should work. What I don't know is how to program this to perform ping and pong, because I have seen that I would need linux and I suppose that later I should make a script or some api that runs constantly, right?
Your post was MOVED to its current location as it is more suitable.
Could you also take a few moments to Learn How To Use The Forum.
Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.
Possibly.
But maybe ask the question on a Pi or Linux forum ?
Many would make an assumption that you were trying to do this with Arduinos.
There are plenty of research papers online, describing techniques to use WiFi for indoor localization. It doesn't work very well, but have you read any of them?
What I don't know is how to program this to perform ping and pong
This approach is described very clearly in the DW1000 documentation, and works fine with the DW1000 modules. It is certainly not limited to them, but use of WiFi introduces a new set of problems to solve.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.