Improper distance values of tag from anchor

I am trying to implement a code where a tag will be attached to a wireless car and 4 anchors are placed in a rectangular pattern used to calculate the distance. Once it reaches to one of the nearest anchors it will take an about turn and move to the starting point.
This is the main motive of my project. I have successfully turned the car 180° when it is coming to the nearest anchor. But after turning the car I am observing the distance values are very inappropriate and not changing at change in distance. So what can be the problem?
Is it because for turning of the tag or due to some other reasons?

I noticed the same behavior.
just by changing the direction of the tag, we will get different distance measurement in different angle, how every after a second this will settle.

i guess it has something to do with the antenna design , it is not transmit even signal in all directions

The antenna and it’s orientation will have a directional effect. You will also get a direction effects on range from to any metal or other conductive material near the antenna. This includes circuit boards.

There will also be an effect due to the anchors. Unless you are heading straight towards/away from an anchor the angle at which the signal hits its antenna will vary which means it’s effective antenna delay will also be changing as you move.

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I would suspect this to be caused by the position of the tag/antenna in the car and line of sight being broken at certain angles.

We have a couple of antenna designs, the antenna of the DW1001 is indeed not perfectly omnidirectional (no antenna is) but it is pretty close. See the Antennea design files for more information. I attached the WB003-Product-Brief.pdf (169.3 KB) since we distribute the antennae design files as an executable to ensure license agreement.

Sorry for late replies,
But now I also tried by attaching the tag with a stick but still after rotating the stick with hand and giving a slight jerk the value changes and I’m getting abrupt distance values.
So what can be the remedy for this problem? Do I need to change the orientation of anchors or any other solution?