GPS glitch crash - help with analysis

Log Analysis -- deprecated Copter Logs -- deprecated
1

Hi,
my hexacopter today crashed because of GPS glitch (I think). After 1:30 min in LOITER the plane started to move very quickly forth and back and then it exceeds 60 deg. pitch angle and just fall. Can I change some parameter to avoid such as situation ? PID’s are from AutoTune which I did just yesterday.

Thanks

Martin

No of lines 5374
Duration 0:01:45
Vehicletype ArduCopter
Firmware Version V3.2.1
Firmware Hash
Hardware Type
Free Mem 0
Skipped Lines 0

Test: Autotune = UNKNOWN - No ATUN log data
Test: Balance/Twist = GOOD -
Test: Brownout = GOOD -
Test: Compass = GOOD - No MAG data, unable to test mag_field interference

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERR found: GPS_GLITCH
Test: GPS = FAIL - GPS glitch errors found (1)
Min satellites: 0, Max HDop: 99.99
Test: IMU Mismatch = NA -
Test: Parameters = GOOD -
Test: PM = FAIL - 3 slow loop lines found, max 14.70% on line 4328
Test: Pitch/Roll = FAIL - Pitch (78.74, line 5173) > maximum lean angle (45.00)
Test: Thrust = GOOD -
Test: VCC = FAIL - VCC below minimum of 4.6v (4.578v)

2

you have a power issue VCC is @ 4.65v which is very low for an APM and all the connected stuff.
What kind of BEC/power module do you have ? can you check the true voltage using a multimeter ?

3

Logging set to low to see what’s going on. Need it set to 45054 so we can get a better picture of what’s going on here.

LOG_BITMASK = 958 to low.

When done testing need to set it back as APM can not keep up with that high of logging.

Mike

4

Hi,

thanks for quick reply. I am using normal 3DR power module. I will check VCC with voltmeter…
Do you think this is the main reason of the failure ?

Thx

Martin

5

Well ! 4.6 is close to 4.5 v which is the lower limit for an Atmel 2560
GPS I think works with 3.3 VCC but depends on the step down regulator between apm and ublox module.