Hi All,
My hex Tarot 680Pro with flight Controller Pixhawk 2.4.7 having Copter 4.0.7 gives same error “mode change failed loiter required position” that too before takeoff, as per my observation GPS is not getting signal,but I am not sure it issue with GPS module or Pixhawk or i miss any setting, because I live in village with full GPS signal for mobile.
Earlier i was using below site to analyze log https://plot.dron.ee/
Unfortunately its not available now, sharing my log file, please find below link.
Set FENCE_ENABLE,1 and wait for the green LED indicating a good 3D fix, then Loiter mode will be possible.
Set GPS_GNSS_MODE,65 to limit the number of constellations, low-end GPS units cant handle more than 2 and update rate slows significantly.
Thanks for quick reply , I was just searching for error in document and found AFS_WP_GPS_LOSS, but that parameter looks retired in latest 4.0.7, i was just planning to enable GPS failsafe to alt hold mode.
Also Shawn, i did not get why it crashed and landed?
It’s a bit confusing around that whole “touched the ground, tried to rise, then move and crash” stage.
The quad is in Land mode for that, and you are over-riding with RC input, so behaviour might not be as expected.
Always just switch to AltHold or Stabilise if strange things are happening.
I think general tuning plays a role. Pitch tuning seems very good, but roll needs some work.
ATC_ANG_RLL_P,3.033925 is very low. Try increasing this to 6 (and more in small steps). If you see oscillations then back it off a little. You should be able to get it up as high as the Pitch value of 9.35.
ATC_ACCEL_R_MAX is quite different to it’s Pitch mate too.
Did you start with the Initial Parameters spreadsheet or MissionPlanner Alt A plugin?
Set this before the next flight too:
INS_LOG_BAT_MASK,1
Just do some AltHold hovering and maybe some gentle movements, then land - let’s see that log.
After tuning is fixed, you might want to check and assess your Land params, something like this for a start
LAND_ALT_LOW,700
LAND_SPEED,40
LAND_SPEED_HIGH,80
then set the speed values based on stability
-> LAND_SPEED_HIGH = maximum descent rate with a slight amount of instability
-> LAND_SPEED = descent rate with total stability, but NOT so slow that landing is not detected
You test the descent rates in Stabilise mode, find the fastest safe descent rate (that you like the look of), then check in the log for what it actually was and use that to set LAND_SPEED_HIGH
Tons of thanks Shawn @xfacta, Generally i do auto-tuning, I just installed new firmware 4.0.7 and I am trying to auto tune, but as loiter is not working I could not switch to auto-tune, after auto-tune, we have to land and disarm to save auto tuning values, and its difficult to land in alt-hold mode, I always prefer to have loiter for landing.
RTL or SmartRTL, in fact any of the GPS-assisted modes, wont work if you lose GPS signal (or comms)
Probably get a more up-to-date GPS unit if you are having trouble.
After auto tune autoanalysis of syslog result is
No of lines 501088
Duration 0:12:14
Vehicletype ArduCopter
Firmware Version V4.0.7
Firmware Hash 0bb18a15
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = GOOD - [+] Autotune 8284-488069
Test: Brownout = GOOD -
Test: Compass = GOOD - mag_field interference within limits (23.53%)
Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERR found: CRASH
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.47, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = GOOD - Motor channel averages = [1574, 1562, 1577, 1556, 1595, 1537]
Average motor output = 1566
Difference between min and max motor averages = 58
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 = GOOD -
Test: Pitch/Roll = GOOD -
Test: Thrust = GOOD -
Test: VCC = UNKNOWN - No CURR log data
That’s the Auto Tune log. Fly it around with some aggressive pitch and roll and see how it does. At least the P/R PID’s are more inline now. Why didn;t you configure the Dynamic Notch Filter before running Auto Tune? Also, you have MOT_SPIN_ARM higher than MOT_SPIN_MIN.
