Hello,
I have a heavy lifting drone– hexa copter. I took the drone out today for its maiden voyage. Using two 6s packs it has Incredible lifting power. It’s still a bit of a wild horse. Biggest challenge I’m having is bringing it down to a soft landing. Any suggestions on how I can tune in mission planner to help soften the landings? The drone weighs about 28 pounds. Has a lifting capability of 40.
Your suggestions are greatly appreciated.
Mike
Share logs.
Yes I will.
What mode are you conducting these landings in?
In Stabilize.
auto trim
Log File C:\Users\Josh Kaplan\Documents\Mission Planner\logs\HEXAROTOR\1\2021-02-13 14-42-34.log
Size (kb) 6214.017578125
No of lines 73569
Duration 0:04:38
Vehicletype ArduCopter
Firmware Version V4.0.6
Firmware Hash 13b6478d
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = WARN - WARN: Large compass offset params (X:4.71, Y:-293.67, Z:297.66)
WARN: Large compass offset in MAG data (X:4.00, Y:-293.00, Z:297.00)
mag_field interference within limits (5.65%)
Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERR found: FS_THR
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.14, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = GOOD - Motor channel averages = [1485, 1559, 1524, 1522, 1500, 1537]
Average motor output = 1521
Difference between min and max motor averages = 74
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 = UNKNOWN - Unknown mode in TestPitchRollCoupling: BRAKE
Test: Thrust = GOOD -
Test: VCC = UNKNOWN - No CURR log data
Log File C:\Users\Josh Kaplan\Documents\Mission Planner\logs\HEXAROTOR\1\2021-02-13 15-10-25.log
Size (kb) 3998.048828125
No of lines 47452
Duration 0:02:25
Vehicletype ArduCopter
Firmware Version V4.0.6
Firmware Hash 13b6478d
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = WARN - WARN: Large compass offset params (X:4.71, Y:-293.67, Z:297.66)
WARN: Large compass offset in MAG data (X:4.00, Y:-293.00, Z:297.00)
Moderate change in mag_field (29.92%)
Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.13, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = GOOD - Motor channel averages = [1192, 1147, 1167, 1180, 1184, 1163]
Average motor output = 1172
Difference between min and max motor averages = 45
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
Log File C:\Users\Josh Kaplan\Documents\Mission Planner\logs\HEXAROTOR\1\2021-02-13 15-16-11.log
Size (kb) 7194.017578125
No of lines 85146
Duration 0:02:29
Vehicletype ArduCopter
Firmware Version V4.0.6
Firmware Hash 13b6478d
Hardware Type
Free Mem 0
Skipped Lines 0
Test: Autotune = UNKNOWN - No ATUN log data
Test: Brownout = GOOD -
Test: Compass = FAIL - WARN: Large compass offset params (X:4.71, Y:-293.67, Z:297.66)
WARN: Large compass offset in MAG data (X:4.00, Y:-293.00, Z:297.00)
Large change in mag_field (52.92%)
Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = GOOD -
Test: GPS = GOOD -
Test: IMU Mismatch = GOOD - (Mismatch: 0.15, WARN: 0.75, FAIL: 1.50)
Test: Motor Balance = WARN - Motor channel averages = [1444, 1329, 1370, 1414, 1437, 1339]
Average motor output = 1388
Difference between min and max motor averages = 115
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
You need to grab the .bin log file from on the SD card, either directly (ejecting the SD card and so on) or downloading over mavlink.
https://ardupilot.org/copter/docs/common-downloading-and-analyzing-data-logs-in-mission-planner.html
Dont bother doing the auto-analysis though.
Just upload the log file to some file sharing service like Dropbox or Onedrive, and post the link to that file in here and we can check it.
Will do.
2021-02-13 15-16-11.bin (3.2 MB) 2021-02-13 15-10-25.bin (1.8 MB)
Here are the BIN files.
Mike2021-02-13 14-42-34.bin (2.8 MB)
Can you download them from here?
2021-02-13 14-42-34.bin (2.8 MB)
I thought of a few edits actually
You are running both EKF2 and EKF3 at once - that might not be an issue and I think plenty of people are using EKF3 now. And it will be the default soon. Probably for a hex of this size and cost I’d stick with EKF2 which is tried and true, at least until tuning is sorted out better.
I guess you have EKF3 enabled for object avoidance? I would disable all optional features until the debugging and tuning is finished, then enable the additional features.
AVOID_ENABLE,0
EK3_ENABLE,0
Only the “AVD” params are required for avoidance using ADSB.
I’d set this boot delay to allow CAN devices (eg: GPS) to boot up before the Cube
BRD_BOOT_DELAY,5000
There’s a couple of other battery voltage related mistakes, set these:
BATT_FS_CRT_ACT,1
BATT_ARM_VOLT,44.3
BATT_CRT_VOLT,42
BATT_LOW_VOLT,43.2
MOT_BAT_VOLT_MAX,50.4
MOT_BAT_VOLT_MIN,39.6
The MOT_BAT params will help with the tuning too.
The Barometer is going crazy, but Baro2 is working OK - not sure what to do about that yet. Maybe lets check it in subsequent flights after the fix-ups
Tuning needs some work, and will be a big contributor to the rough landings
I think these are too low
INS_GYRO_FILTER,15
INS_ACCEL_FILTER,10
I couldn’t tell from the pic what prop size you’ve got, but took a guess and I’d probably set these until we know more details.
ATC_RAT_YAW_FLTT,10
INS_ACCEL_FILTER,20
INS_GYRO_FILTER,20
Let us know the prop size.
If you using T-Motor Flame ESC’s then set MOT_THST_EXPO,0.2
It will definitely be worth the time and effort to set up the Harmonic Notch Filter
Do a test flight with these params (and all the rest from above), stick to just hovering for a while, and maybe a few gentle movements.
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,0
Post that .bin log file and we’ll go from there.
Once we’ve got these things nailed down, we can move onto PIDs and Autotune - there’s work to be done there!
Have a read over the Tuning Guide too, it definitely applies to these larger aircraft.
https://ardupilot.org/copter/docs/tuning-process-instructions.html
EDITS
Landing in Stabilize mode will always be a bit tricky. AltHold will be a better mode to use for testing and almost all flying except for when you want LOITER mode. It’s excellent that you’ve done a lot of flying in Stabilize mode as that is still the emergency go-to mode.
AltHold has the freedom of movement of Stabilize, but holds altitude (obviously) and “throttle” is from the centered position.
Actually spring-centered throttle is the way to go, and set PILOT_THR_BHV,7
I think you could set these PIDs and it will help before the next test flight, but as per the Guide, reduce them if there’s oscillations, particularly the ANG P values.
ATC_ANG_RLL_P,6.5
ATC_ANG_PIT_P,6.5
ATC_RAT_RLL_P,0.10
ATC_RAT_RLL_I,0.10
ATC_RAT_RLL_D,0.005
ATC_RAT_PIT_P,0.10
ATC_RAT_PIT_I,0.10
ATC_RAT_PIT_D,0.005
Wow. You were spot on with my configurations. Thank you very much for reviewing. I’ll make the changes and let you know how she flies. I am using avoidance Collision. I have the tera ranger evo sensors installed. Two in the bottom and one installed on each side. A total of eight. And, yes I have two GPS’s installed. Problem is it’s not easy to calibrate the GPS’s because my arms get tired while trying complete the process. Remember, the weight of the drone without a payload is around 25 lbs. The thrust is very powerful. The drone takes off like a rocket. Have to watch out not to give it to much throttle at once.
Thanks again, and I really appreciate you looking at the logs and making suggestions.
Let me know if there’s any other suggestions that you may think of.
Mike
Lastly, the one issue that I have continue to have is that when the drone comes to a landing it is tipping over before I get a chance to shut down the motors. I reconfigured with a different set of landing gear and still getting the tip of a problem. I’m now thinking of installing additional landing gear just be on the pivot point of each arm.
Yeah maybe set up some temporary extra landing stabilisers. I still think the timing will fix the problems.
EDIT: I meant to say “tuning will fix the problems”
The props are the KDE-CF245-DP Propeller Blades, 24.5" x 8.1
and I am using the KDE7215XF-135 Brushless Motors with the KDE-UAS125UVC-HE 125A+UHV Electronic Speed Controller (ESC’s).
What would you suggest for:
ATC_RAT_YAW_FLTT, ?
INS_ACCEL_FILTER, ?
INS_GYRO_FILTER, ?
I make the changes to the Prems. On a bench test I 'm getting "No EKF3 cores and “EKF attitude is bad”
