All the Betaflight gyro filters explained

Support my work / pawelspychalski
Modern FPV drones fly great thanks to two primary factors: great hardware and great software. You know, Betaflight, PID tuning, filtering, etc. Today, let’s take a detailed look on the Betaflight gyro filtering. Which filters are executed in which order and let’s quickly explain what each of them does.
Oh yes, we will cover Dynamic LPF, Dynamic Notches and of course RPM Filter!
Betaflight 4.3 full setup guide | From flash to flight • Betaflight 4.3 full se...
0:00 How important gyro filtering really is?
1:25 Filtering versus phase delay
3:12 Betaflight Stag2 gyro filter - the one that does antialiasing
4:26 Betaflight RPM filter
5:45 Static Notch 1 & Static Notch 2 filters
6:48 Dynamic gyro LPF filter and static gyro LPF filter
7:55 Dynamic Notch filters
9:09 Outro

[@FPVUniversity]

Betaflight 4.3 full setup guide | From flash to flight kzbin.info/www/bejne/lZq1eHhomr9rhsk

[@aemarkov]

It would be nice to have such video for Inav filters.

[@Tonynux]

Really really really interesting!

[@Eugenue]

I suggest to explain how RPM filter works. How it handle an information from ESC.

[@Eugenue]

Thank you very much for explaining FPV technical points

[@VladVortal]

Nice

[@FPVUniversity]

thanks

[@notice_fpv]

Would LOVE to see a simple video on interpreting noise seen in blackbox Explorer to better understand how to employ the filters.... Not sure it's possible, though (the simple part).

[@BBFPV]

Next: All the INAV gyro filters explained

[@FPVUniversity]

Next I'm planning Betaflight PID loop without mysteries

[@Tonynux]

@@FPVUniversity good idea!

[@volkergoe]

Excellent roundup! Will you cover D-filtering in a separate video?

[@FPVUniversity]

I might if there will be a enough of the requirement from the community

[@Tonynux]

@@FPVUniversity it should be necessary to complete the "filters" topic.

[@Tonkabollocks]

Excellent Professor! ; ) Would you agree that: 1)flat cnc'ed (high modulus/carbon) laminate, aligned perpendicular to the common thrust vector AND 2) motor (magnet) 'cogging' vibations, co-planar with RIGID arms are the biggest sources of VIBRATION and impact failure, as well as poor aerodynamics, along with common 'brick like' power packs! (a la 'Dji FPV'!)

[@sullytrny]

If you haven't yet, all the sliders! And rth in 4.4? Thanks

[@mrthingdudeman]

This is great, but the explanations are from the backend and high-level. It would be great to explain this using the configurator. Setting the CLI commands are specific, but don't really help those people, like me, that are trying to understand the configurator. For ex, when are the D-Term filters run? What are the effects using them? When should they be high? Low? Also, what are the different filter types? How should notch filters be set? What sort of data in blackbox is seen, and what can a filter do to rectify it? What sort of cut off values should be used? There are a huge list of questions and reasons to know here.

[@Mupshot]

flying vibrators? OWCH. Filtering in Betaflight and tuning in INAV are things that I still struggle with. Knowing what FC are truly supported in INAV, or how to find a suitable target for a board that in specs should be able to fly INAV. eg HACRC F405D on paper should support INAV, but no official target in INAV.

[@Tonkabollocks]

Glad you liked the 'Professor' moniker! ; ) Like @morton upshot (below) I also would love to know if the (necessary) filtering (suite) that Beta flight apears to have is ALSO available in iNAV and Ardupilot/copter/wing!

[@FPVUniversity]

They are different. I will make a video on INAV one for sure. Similar, but with differences

[@john_h9281]

Excellent video Pawel.. Any video on this subject and tuning are so useful Perhaps some guidance and what filter changes maybe required when building 7 inch quads as against 5 inch rigs !! I don’t have any 7 inch quads and I am reluctant to build one as I get the impression that the Betaflight default settings which work really well for 5 inch are not so good for 7 inch rigs and I am not a sophisticated tuner !! Thanks for the video 👍👍

[@FPVUniversity]

In general, you have to lower LPF filter frequencies. Probably to 90Hz for gyro and Dterm. Also lower min. frequency for RPM filter and dynamic notch

[@john_h9281]

@@FPVUniversity Thanks Pawel 👍

[@redacted1946]

5:08 im not sure this is correct. You mention that rpm data can come by either esc telemetry or bidirectional dshot, I don't think esc telemetry is used at all for rpm data because the slow round robin uart used in esc telemetry is too slow to be used for anything like filtering. And that bidirectional dshot is the only thing that can be used for rpm data for the rpm filter Also i really like these deep technical dives especially about how internals of the PID's and filters work. More videos like these are great. Also more low level things about stm32's etc i find very interesting as well and would love more content related to lower level coding things.

[@remainsmemories626]

"flying vibrators" I've seen a video that began the same)))

[@FPVUniversity]

he he he

[@cwwisk]

We need a gps crash tracker system. I don't want these to display owner data or anything, but I lost my INAV quad a couple days ago because there was a control link loss after video loss and RTH didn't work. A person would need general coordinates, protocol, and date/time information to access "last known GPS ping" or something like that. Let's say I was using UBLOX protocol on a home-built quad and supposedly lost signal in a general area on a specific day. If I typed this into a search, I would get some sort of map with a pin at the last ping location in order to help me retrieve my quad. Do you know any way to set up something like that? I would say it would probably require a decent server base to keep temporary ping files for a couple days. This would help so many people, as long as it remains anonymous. Does anyone know of anything like this that already exists?