Upward facing lidar - avoidance issue


I have an issue with avoidance since 4.0 version.
When avoidance is activated, whatever flight mode, avoidance is not stable. In fact, the lidar (upward facing) save the correct centimetric measurement but the drone oscillates up and down (about 20-30cm). I want to correct that but I have no idea how… The goal is to delete or reduce the oscillations.
I don’t have GPS and I have only one lidar upward facing.

Is there anybody else with the same issue? Is it possible to delete or reduce it ?

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Did you tune the PIDs? and did you tune the altitude PIDs after that ?
Just search this forum for tuning instructions and you will get:

could you please send BIN log file ?

Apparently, it’s not a PIDs problem…but thank you for your reply!

Someone told me that you could possibly help me with this issue… @rmackay9 please

Please post a .bin file, without it he can not help you. I’ll re-post one of my posts here again, because it pertains to the altitude controller:

Did you tune the dynamic notch filter to get rid of Z-axis vibrations first?
Did you follow the required tuning instructions before doing the autotune ?
You you did not follow the steps above previously, repeat the autotune. Did the P gains increase? is the copter stable in stabilize mode? if yes, proceed, if no, repeat the autotune, before continuing to the next step.

If you did all that correctly, then you should try understand altitude in ardupilot and after that tune the parameters for the altitude controller.

If you need more information, read ardupilots’s control loop detailed implementation
But most probably you will get excellent results by just following the first few links that I posted.

As everyone is trying to tell you, without the .bin file from a flight showing the problem there is little we can do but point you to the areas of information that we all had to read and digest and learn from.

If you want the benefit from our learning then post a .bin file from the flight controller and you will find people willing to help.

No information = no help

Hello my man…nice to meet you all
I want quest about setup upward facing lidar
I’m using Lidar liter v3, in orientation forward facing lidar, the object avoidance can work
but if i’m setup orientation upward facing, there massage Prearm check proximity sensor

any idea ?
thanks before