PIDtoolbox Q&A #04 | Latency and Phase Delay 

thanks Mark!

Yes it’s definitely more meaningful when we think in degs at specific freqs instead f ms. 2-3ms doesn’t carry much meaning to people but when you can see this causing 30-40deg phase shifts then the issue is clear. Got thinking about this more through conversation with Chris Thompson.

exactly!

Yes that’s right, the order here is not exactly meaningful. Though rx latency is certainly before since set point (rates) are computed from that signal after it arrives in the FC right

@@PIDtoolbox but a rc curve (thus a rate) could be set. maybe that was his idea

Sorry to hear that. PM me and I’ll do my best to help.

@@PIDtoolbox Thanks! I enjoyed the discussion. Definitely could have kept watching. I'm no programmer but it seems like code could be implemented that in propwash the FC could calculate the phase delay on the fly and advance the P freq, sorta like a feedforward for P thus reducing the phase delay.

yea, unfortunately nothing more interesting happened lol. but Im surprised you watched till the end. I was afraid it was getting sleepy lol

@@PIDtoolbox Sure I watched it, but I must admit I skipped the first parts about rc link and stuff. Not much new for me… I have a really tricky 10 inch and after having a bad fc and a noisy esc I might still be running to high filtering (had massive freak outs and this is no fun with 10inch and 2,5kg). And this is my main thing: how much filtering is really necessary. For me I guess I use too much. There was one video by uavtech where he tuned a 3inch and it looked so noisy at first but it was flying fine. But yes how much filtering is really necessary. Sadly I was not able to fly for a long time, so I still have to try out what I learned from all you guys.

@@jas-FPV depends on if you have the bosch gyro (radix), which has less internal filtering. Also a 10inch is mainly for cruising so more filtering wont kill you too much, but opt for more dterm filtering over gyro LPFs. also maximize RPM and DNs so you dont need as much gyro LPF filtering. the gyro LPFs are the real killer

@@PIDtoolbox Yeah. I got misled by all the hardware issues I had with it. Iflight dual, both gyros bad, replacement fc also. Iflight 60amp esc noisy as hell…. This leads to wrong decisions regarding filtering 🤷🏼‍♂️ Yes I will restart the tuning with gyro at 2.0 and go from there.