I have a setup with 4 anchors and 2 tags. I use the DWM1001 module. I read the distance values from the tags and calculate the position myself.
My application requires quite high position accuracy. The average distance error must be within ±30 mm. I am aware of that the distance values fluctuate more than ± 30mm, but that we can handle with filtering. But the average error needs to be within these limits.
My problem is that the average distance error is often a lot bigger than ±30 mm. And also it varies a lot when i move the tags around. I have attached a plot where I have plotted the distance offset as “true distance - average measured distance”. The X axis is distance between tag and anchor in mm. Each cross represents a 60 s measurement with 100 ms update rate.
As can be seen the offset is large, typically 50-150 mm. Also it can be seen that while the tag is in the same position the offset is fairly constant. But when I move to a new position the offset is changed.
I have some questions:
Is there any explanation to why the offset differs so much when the tag is moved?
What is expected value of the max offset?
Is there any possibility to improve this behaviour when using the DWM1001?