I am currently working on a project that involves using the DWM1001 module for localization, and I have a few questions regarding its functionality that I hope you can help clarify:
Anchor Capability:
Is a DWM1001 tag capable of communicating with only the same set of 4 anchors at all times,
or does it have the capability to automatically switch to different anchors when it moves from
one region to another?
Tag Capability:
Is there a way to modify the tag’s capability to interact with more than 4 anchors, such as
expanding it to 8 or 10 anchors?
Localization Methods:
What are the common methods used for localization when multiple anchors are involved?
Specifically, how is localization managed when the number of anchors exceeds the default
capability of the DWM1001 system?
Yes, the system can cope with more anchors and will automatically switch as the tag moves.
No, each tag will only use 4 anchors at a time.
Not sure. I think from memory it calculates location from each available set of 3 beacons (so once with 3 beacons or 4 times with 4) and then picks the result that is “best” but I could be completely wrong about that.
If not running PANS and writing your own position calculating firmware:
Yes. Assuming you design the system that way.
Yes. Assuming you design the system that way.
Depends how you design the system.
Generally I wouldn’t recommend this. To give you an idea of what would be involved there is example code of ranging to a single anchor. A quick search of this forum will find you lots of people asking for help on how to expand that to multiple anchors, most people manage to get that working. There are then lots of examples of people asking how to expand it to multiple tags, that tends to have a somewhat lower success rate. There are very few people asking about how to calculate positions, I’m not sure if that is because people find it easy or because the people who get to that stage are the ones more able to figure it out without help.
Either way the number of people here who have their own position system is very small, generally if you want multi-tag positioning then either make do with PANS and live with it’s limitations or expect to spend a lot of time getting things working.
That said if you put the work in then you can get some very good results. For example the system I built will support up to 200 anchors but (currently) only 5 tags. Each tag will select the 12 best anchors to measure ranges to and will calculate its position using a least squares based calculation that will use all of the available ranges. We get 5 tags, each updating at 100 Hz and generating positions with a 3 cm standard deviation from their true location. But it took a couple of years to get to that point.
. Just to add - yes it automatically switch to new anchors when it becomes to a new area.