PX4 Quadrotor · 2023-05-08

Flight telemetry summary

Distance Meters

2.2 m

Maximum Altitude AGL

2.2 m

Maximum Ground Speed

1.05 m/s

Minimum Battery Percent

0%

Minimum Battery Voltage

-0.37 V

Minimum GPS Satellites

11

Maximum GPS HDOP

1.01

Flight Modes

POSCTL

Maximum Distance From Home Meters

2.8 m

Maximum Distance From Home Time

2m 17s

Average Ground Speed

1.03 m/s

Maximum Climb Rate MPS

0.45 m/s

Maximum Descent Rate MPS

-0.45 m/s

Voltage Sag

0.07 V

Flight Mode Seconds

POSCTL: 2m 29s

Maximum GForce

10.8 g

EKF Healthy

Yes

Weather at the flight

Source

open-meteo-archive

Sampled At Utc

2022-12-15T09:00Z

Latitude

31.88

Longitude

120.99

Temperature C

8.4 °C

Wind Speed MPS

2.61 m/s

Wind Direction Degrees

122

Wind Direction Cardinal

ESE

Weather Code

0

Weather Description

Clear

AI flight report

This was a very short, very local flight: 2:29 total, staying in POSCTL the whole time, with a farthest distance from home of just 3 m (reached at 2:17) and a max altitude of 2 m above home (recorded at 0:57). Ground speed never exceeded 1.1 m/s (0:55), and the aircraft spent most of its time hovering or barely creeping around near the launch point, climbing and settling between roughly 1-2 m AGL according to the telemetry samples. Weather was cold and clear (8.4°C, light 2.61 m/s wind from the ESE), so conditions don't explain any of what follows.

The data quality and airframe behavior are the real story here. Battery reporting was broken from the first second: the log shows 0% battery and negative voltage (-0.3 to -0.4 V) throughout, alongside a BATTERY_CRITICAL event at 0:00 — voltages below zero aren't physically real, so this points to a sensor or logging fault rather than an actual power problem. Separately, a barometric-vs-fused altitude disagreement of 86 m was flagged at 0:00, and the derived diagnostics show this gap widening to 88.1 m by 2:27, meaning the barometer and the fused position estimate never agreed for the entire flight. On top of that, the log recorded nine separate "impact or hard landing" events (0:07 through 2:18), with severities from 3.1 G up to a sharp 7.8 G spike at 2:18 — right near the end of the flight, close to the 2:17 farthest-point mark and shortly before disarm at 2:28. Given the aircraft barely moved and stayed under 2 m altitude, these repeated hard-impact readings alongside a 784 µs motor spread and a peak motor output of 1925 µs (both at 0:08, near the ESC's ceiling) suggest the airframe was fighting to stabilize on the ground or just above it, not doing normal flight maneuvers.

Given this pattern, I'd treat the battery and altitude readings on this log as unreliable rather than as real warnings — the negative voltage and the 86-88 m baro/fused split are both signatures of instrumentation or fusion problems, not genuine power or altitude events, and would need cross-checking against raw sensor logs before trusting them again. Separately, the repeated hard-impact events combined with the near-saturated motor output at 0:08 point to the vehicle struggling for control authority very close to the ground; before the next flight it's worth checking prop balance and CG, since a sustained motor spread like that usually means the mixer is compensating for an asymmetry rather than just reacting to a gust.

Detected flight events

1. 0s — Battery below 15%

   Battery below 15%. Battery at 0%. The aircraft should land as soon as possible.

2. 0s — Barometric and fused altitude disagree by 86 m

   Barometric and fused altitude disagree by 86 m

3. 7s — Impact or hard landing: 3.6 G

   Impact or hard landing: 3.6 G

4. 16s — Impact or hard landing: 3.1 G

   Impact or hard landing: 3.1 G

5. 27s — Impact or hard landing: 3.5 G

   Impact or hard landing: 3.5 G

6. 34s — Impact or hard landing: 3.5 G

   Impact or hard landing: 3.5 G

7. 54s — Impact or hard landing: 3.5 G

   Impact or hard landing: 3.5 G

8. 55s — Maximum ground speed: 1.1 m/s

   Maximum ground speed: 1.1 m/s — the fastest the aircraft moved over the ground.

9. 57s — Maximum altitude: 2 m above home

   Maximum altitude: 2 m above home — the highest point of this flight.

10. 1m 22s — Impact or hard landing: 3.2 G

    Impact or hard landing: 3.2 G

11. 1m 28s — Impact or hard landing: 3.2 G

    Impact or hard landing: 3.2 G

12. 1m 46s — Impact or hard landing: 3.1 G

    Impact or hard landing: 3.1 G

13. 2m 18s — Impact or hard landing: 7.8 G

    Impact or hard landing: 7.8 G

14. 2m 28s — Vehicle disarmed

    Motors disarmed — the flight is complete.