RTLS to track down 1m3 sized cage

Hi All,

I am planning to make a cage that I want to track down several moving locations.
Before I start to buy and build my project I would like to make sure that my plan is ok to go.
So some questions here and I need your help to solve.

The cage is roughly 1m x 1m x 1m, and I it’s TDoA system.

  1. Then, anchors will have only 1m distance between them, would it be a problem since it is too close?
  2. If it is ok, then, maybe, the accuracy would be even better than typical accuracy(10cm)? The tracking range is a lot smaller then usual.
  3. What about the sensing data from sensors in a tag? Sensing data will also have some tolerance? Or it is just as exact as wired?
  4. Super long battery life in tags is crucial in my project, The tags will run on CR2032 more than a year?
  5. What if I put 2 tags with 3cm next to each other, does it appear as it is? Or is it too close to distinguish?
  6. The orientation of tags (how you place it) effect the accuracy?

Anybody here? Hellu…


Some answers below :

  1. Those figures are quite small. Theoretically it may work, but you need to to a field test to verify it. I’ve already seen TWR system working in a satisfying manner in 2mx2m area.

  2. The accuracy will no be improve, the RTLS quality may actually be worse because 10cm is a much bigger error relatively to 1m.

  3. Not sure what you mean by sensing data.

  4. TDoA allows for very long battery life, depending on how often the tag blinks and how often you need to track the device.

  5. It should be possible to have multiple tags but due to the 10cm error and the limited area to track, having a too large number of tags will result in poor performance (it will be difficult to identify tags)

  6. Orientation of tags mainly have an impact on radiated powers and range. This should not be an issue as you are looking at very short distances.

I’m not sure the performance will be sufficient with a 1m*1m area, but you can give it a go and see.

Hope it helps,

1 Like

Thank you Yves, it was very helpful.