Flight Log Analysis

Cube Autopilot
1

Hi all,

I got my cube black / f450 clone out of storage recently and finally got out to the field. Can someone take a look and tell me what next steps for making this quad more solid are?

Bin: https://drive.google.com/file/d/1VQjmtdzpCWPrSr2YEJzOIA5MbFWyoV1M/view?usp=sharing

Log File C:\Users\brennan\AppData\Local\Temp\tmp2DAE.tmp.log
Size (kb) 31446.107421875
No of lines 357076
Duration 0:15:50
Vehicletype ArduCopter
Firmware Version V4.0.5
Firmware Hash 3f6b43e3
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = FAIL - Large change in mag_field (129.69%)
Max mag field length (1133.72) > recommended (550.00)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.30, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = WARN - Motor channel averages = [1446, 1497, 1506, 1538]
Average motor output = 1496
Difference between min and max motor averages = 92
Test: NaNs = FAIL - Found NaN in CTUN.DSAlt

Test: OpticalFlow = FAIL - FAIL: no optical flow data

Test: Parameters = FAIL - ‘MAG_ENABLE’ not found
Test: PM = FAIL - 68 slow loop lines found, max 7.80% on line 173641
Test: Pitch/Roll = GOOD -
Test: Thrust = GOOD -
Test: VCC = UNKNOWN - No CURR log data

2

Your compass is strongly affected by your motors.

image
image1667×1004 156 KB

The red line is the total mag field strength. It shouldn’t change much. You can see that it follows your throttle output (green). This is what is generating this error: Test: Compass = FAIL - Large change in mag_field (129.69%) Max mag field length (1133.72) > recommended (550.00)

This is affecting the EKF’s position estimate (the red and blue lines on the map should match), and it sometimes gets close to triggering a failsafe. The graph is the EKF’s magnetic consistency check. If it exceeds 2.0 for long enough, it will trigger a failsafe.

image
image3346×1059 662 KB

You need to do a compass-mot calibration (ideally with a working current sensor), or get your compass away from your power wires. Also make sure your power wires are twisted or tied together.

2 Likes
3

100% what @Anubis said
move your compass away should be prio no1.
second is compass-mot.

4

I’ve got the compass mounted up about 4-5 inches now on a GPS mast and will test fly later this week to verify that the distance is enough to counteract the interference. I realized that my main power wires were directly under the compass and it was flush mounted on the top of my F450 top plate.