Pixhawk seems to do not use px4flow with LPE

hi, all
i have tried to fly my multicopter indoor.
and i succeeded in that a month ago.
but now it doesn’t work anymore.
i’m using fake gps, LPE and terrain following for LPE to make flying indoor.

is there any kind of parameter i should check out again?

hardware :
3dr gps

firmware :
1.4.1 master for pixhawk
master version for px4flow

What messages are you seeing in QGC during a flight where you expect flow to work but it doesn’t?
Are you using the sonar of the PX4FLOW module for ranging? Is that delivering good measurements?
Can you share a log file of such a flight?

messages keep displaying “flow timeout”.
and i’m trying to get log file.
thank you for your attention

If you’re seeing “flow timeout”, flow is working in principle, but it can’t be used for state estimation for some reason.
Reasons include poor flow quality (the camera doesn’t have good features to track) or bad height above ground estimation.

The message is printed here: https://github.com/PX4/Firmware/blob/9c82293bc484e62b1bc4e405c3cf86169f703256/src/modules/local_position_estimator/sensors/flow.cpp#L208

You can see that this depends on _time_last_flow, which is updated in flowMeasure(): https://github.com/PX4/Firmware/blob/9c82293bc484e62b1bc4e405c3cf86169f703256/src/modules/local_position_estimator/sensors/flow.cpp#L116

If flowMeasure() returns before getting to the end, the timeout will occur. You can look at all the possible causes in that function. That should give you a good indication about what to look for in your log.

Since you had it working indoors, but have problems outdoor, you are either having problems with the camera not seeing features because of bad lighting conditions (asphalt in bright sunlight e.g.), or your ranger is not providing good measurements. For a light based ranger, again sunlight will be causing problems. If you’re using a sonar ranger, the ground might not be sufficiently reflective (e.g. deep grass).

here is the log
is there any problem??

Please upload your log to http://logs.uaventure.com/

i’m sorry ,
i’m not good at this stuff.


No worries.

From what I can see, flow is being fused after about 8 seconds in that log. What tells you that it’s not working?

changing to POS_CTL works with my controller In QGC, but real flight.
that is the problem i got
i just figured out the mode was ALT_CTL (you can see that in the log linked)