Are the 4.2 settings for optical flow the same as just using FlowHold flight mode?

I’ve spent the day preparing to try 4.2 beta and it’s improvements for Optical Flow.

I spent several hours calibrating flow_fyscaler and flow_fxscaler. I’m curious to see the difference the automatic calibration sets for these parameters.

I did some testing in Flowhold to see if the changes improved performance. They did - although in Flowhold, the copter is a bit twitchy - as if the PID’s were out of whack.

Looking ahead at the procedure in the docs for the 4.2 optical flow auto calibration - I was wondering if just switching to flow hold would be the same as the parameter changes:

optical flow settings

I know that RTL is supposed to work with optical flow, but I’ve never read that optical flow allows identification of waypoints required for flying in Auto.

If anyone is curious about the performance of my copter in Flowhold versus Loiter - the comparison is in this BIN file: Dropbox - 2022-03-03 15-01-45 flowhold and loiter after manual of calibration.bin - Simplify your life

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Hi @jstroup1986,

Txs for all this testing, really great!

In general I don’t recommend using FlowHold on vehicles that have a lidar because it doesn’t perform as well as Loiter, PosHold, etc. The mode was really developed for the SkyViper copters that have an optical flow sensor but no lidar. On these vehicles it’s better than nothing but for vehicles with a lidar, might as well use it.

Switching to FlowHold is not the same as making the listed parameter changes. They’re unrelated…

Yes, RTL (and all other modes for that matter) will work as long as the vehicle stays within the lidar’s range. If the vehicle doesn’t have a GPS then you’ll need to set the EKF origin which can be done from Mission Planner by right-mouse-button-clicking on the map.

To calibrate the opticalflow I highly recommend using the inflight calibration procedure. It should be better than the manual procedure.

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did you mount and install a GPS?
did you also mount a downfacing lidar rangefinder?
Do you experience the holding height issue?

Agree, FlowHold flight mode with optical flow and lidar is a really bad experience.