Strange Behaviour

ArduPlane Plane 4.0
1

strange behviour at distance when RC telem power interfence…like PID gains are reduced

reducing max power on telem to 25mw solves the issue

Questions:

  1. Why does it take EKF3 so long to become active?
  2. Why to scaled position innovations appear so noisy, yet not really close to 1 at any point? the RX and GPS are relatively close, leading one to suspect the RF from the RX telem
  3. The GPS thinks its accurate as far as I can tell

Ultimately what causes the poor adherence to demanded attitude at the end of the flight after EKF3 becomes active?
@tridge

2

GPS accuracy is quite bad:

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Position innovations are indeed very strange:
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the reported PN/PE position is jumping quite a lot:
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still working on why this happens
@Paul_Riseborough can you take a look?

3

thanks…thanks…my question is if position gets bad, why does the demanded att vs act att get so sloppy? I could understand that the demanded att/navigation gets wonky…but whye doesnt the rate controllers keep the actual and demanded still tight?

4

May I ask which type of telemetry creates this trouble?
Thanks.

5

It looks like the EKF didn’t complete its yaw alignment to GPS until 3 minutes after takeoff. This resulted in bad health after the yaw was reset and GPs aiding started that required a couple of minutes to sort out. This is currently one of the risks associated with flying without a compass. I will check the log and see what could have prevented it doing the yaw alignment to GPS that is normally performed as soon as a flying condition is detected, but preliminary analysis indicates the GPS quality checks were not passing preflight. For example look at the large GPA.SAcc value.

6

CRSF telemetry was in use

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