Performance vs Number of Anchors

Hi, I have a room that is 10m * 5m and I want to achieve within this room the best accuracy I can, while tracking at the same time, 5 different moving DW1000 modules. Would the performance increase if instead of 4 Anchors (one for each ceiling corner), I deployed, 15 anchors sparsed around on the ceiling and walls? I say 15 because in total I do have 20 such modules available which are based on dw1000.

Can I reach better than 10cm accuracy you think?

Hi Gouz,

Can you confirm you are using DWM1000 module ? If yes, then which firmware are you planning to use ?

In theory, ones could develop a RTLS system in which anchors redundancy mitigates the error. So indeed, a small room with 15 anchors could track 5 tags in a very accurate way. But please note that it may required advanced software feature which Decawave currently does not provide.

If may need to implement your own RTLS stack.

Hope it helps,

I can’t speak to the system you bought and what limits it has, but increasing anchor count, IF the system can use them in the solution, will increase the precision of the system. this is analogous to having more GPS satellites in view improves your location precision.

Our system has no practical limits on the number of anchors you can install as every anchor which hears a tag is used in the solution. For example, we put 56 anchors in the ceiling of a basketball arena. That system could operate at about the 1 cm level of precision on a single tag beacon. The system objective was to get very high accuracy and very high update rate (over 3000 locates per second) for athletic tracking.

Another way to increase precision is to beacon more often than you require and filter/smooth the output. This has the effect, somewhat, of multiplying your anchor count. This helps reduce the position noise. It does not help reduce systemic errors, however, from bad geometry or other issues.

For example, we can show off our system in “ludicrous mode” with tags at 100 Hz beacon rate and averaging 20 hits to get a 5 Hz net output. Using about 12 anchors, this produces roughly +/- 1 cm position noise. If you have the locate capacity, and the battery life allows it, this is a great way to increase system performance.

If we combine the 56 anchors and smoothing over 20 hits, we are down to a few millimeters of position noise.

Yes, UWB can do that, pretty easily, in the XY plane. The Z axis is harder, but can also be achieved, particularly if you can get anchor Z axis diversity.

Essentially, your accuracy should be limited only by the money you have to buy anchors.

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
+1 812 962 9408