flow deck outlier filter - after update to new FW version

Firmware/software/electronics/mechanics
Post Reply
wydmynd
Beginner
Posts: 25
Joined: Thu Dec 06, 2018 9:25 am

flow deck outlier filter - after update to new FW version

Post by wydmynd » Sun May 05, 2019 2:03 pm

hello

I am working on expanding on the mapping demo using ranger deck.

I noticed that my CF 2.0 is crashing from time to time when using flow deck. I'm moving at slow speeds 0.15m/s using mellinger controller.
when logging the motion.deltaX , motion.deltaY parameters (raw data from flow camera) I noticed before the crash a "spike" of about 40 pixels per frame. (or per logging interval?) - the outlier filter is set at +-100 pixels (by default).
after changing it to 40, the drone seems to crash less. but motion.outlierCount parameter is always zero...
also, after updating the project to the newest version (using VM) the deltaX/Y values are now in the 100s and 1000s , cannot find what caused the change.
I have not enabled the low pass / MA filters that are available in firmware and are disabled by default.

will be very glad if you could comment on one or more of the following --

- did anyone try to log the motion data or the outlier filter ? any tips?
- did anyone try to tweak the outlier filter to reduce crashing?
- any idea why the outlier filter data seems to be stuck at zero? or why after updating to latest version the flow raw data is different?
- what is your opinion on the LP/MA filters? do they distort motion accuracy? ( I want to use the CF in a situation where I try to rely on the stateestimate distance measurements )

thanks alot.

tobias
Bitcraze
Posts: 1867
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: flow deck outlier filter - after update to new FW version

Post by tobias » Mon May 06, 2019 11:37 am

Could you try to investigate a bit more about the new FW behavior? From what I know there should be no difference...

The flow algorithm could probably be improved a lot, especially the error handling, so we are happy that you are trying!
- did anyone try to log the motion data or the outlier filter ? any tips?
Yes, at least the motion data and it is pretty noisy but when accumulating it it is also fairly correct. The outlier filer I have not looked at though.
- did anyone try to tweak the outlier filter to reduce crashing?
I have not, but I know the readout is per logging interval and not per frame.
- any idea why the outlier filter data seems to be stuck at zero? or why after updating to latest version the flow raw data is different?
Sorry, no...
- what is your opinion on the LP/MA filters? do they distort motion accuracy? ( I want to use the CF in a situation where I try to rely on the stateestimate distance measurements )
As long as the data is not distorted I don't see more then a potential latency problem.

wydmynd
Beginner
Posts: 25
Joined: Thu Dec 06, 2018 9:25 am

Re: flow deck outlier filter - after update to new FW version

Post by wydmynd » Mon May 06, 2019 3:07 pm

thanks! I will try to use the low pass and report back

Post Reply