Getting AQ airborne - starting problems

[JensKa]

Hi there,

I am basically familiar with copters, but new to AQ. For the last 2 weeks I am trying to get my AQ flying. From here I start to get pretty frustrated, since it flipped this morning during low level hover. Broke 2 Xoar props, motor mount plate and one motor bearing.

My configuration:
Flyduino FCP-HL frame
Tiger MT2216-800kv with Xoar 11x4
Flyduino 20A ESC (SimonK)
4s2p 5000mAh
AQ FW ver: 7.0 - BETA rev442 b1848, HW ver: 6 rev1 - with DIMU 1.1
Quadro-X setup, default PIDs.

Although my target configuration is an X8, I disabled the lower 4 motors and configured it as an Quadro-X - for first hovering and to get the hang on the AQ configurations.

With a mixing table of +/- 50% on tilt and roll I had severe problems during indoor test hovering. The AQ was twitching all over and starts flipping over motor A after a short time. I understood this phenomenon as motor clipping/saturation with different reasons for that. So I reduced the mixing down to +/- 30% on tilt and roll, and tamed down IMU_ACCX/Y readings down to +/-0.5~0.8 with all 4 motors running on the ground. I could not get it lower, although all props have been balanced twice.

After having done that, the twitching/flipping was gone - at least during low level indoor hovering. So I thought I'll give it try this morning and did the first outdoor hovering on our lawn. In manual mode hovering in ~1-2m height was fine. The AQ was responsive and pretty stable. So I continued hovering and switched to PH mode. Instantly the AQ hardly flipped and crashed on the lawn.

Unfortunately there was no SD card inserted, so no log file. GCS screenshots of my config attached, also the last IMU_ACCXY reading on the ground just before the crash flight.

What am I missing, why is it flipping instantly after switching to PH, but not during hover?

Thx in advance, Jens

[sandmen]

Jens, reducing Mixer values are not the correct way.
Why, you didn't adjust the PID's instead the mixer?

[JensKa]

I did this particular change after reading this german thread from rosewhite:
http://fpv-community.de/showthread.php? ... post367822

Please advice what is the correct way instead, I am willing to learn.

jens

[sandmen]

I already wrote, tune your PID's.

[JensKa]

Ok, which PID parameters should I begin to change, Tilt angle P, ... ?

I still need to understand why it flipped suddenly when switching to PH, while in normal hover it did not.

Jens

[aBUGSworstnightmare]

Hi,

TARE and onBoard Mag calibration was done and values stored to EEPROM? Have you checked your motor connections? Since you're using PWM simply set the 3 other ones to CAN and verify your motor position (mixer) and motor direction is correct.

Joerg

[JensKa]

Hi Jörg,

both calibrations have been done before and stored in eeprom. Quadruple checked motors and connections, all OK. If there would have been an error, it would not hover in manual mode at all, would it.

Update: I just found an error in my magnetic incl./decl. settings. Instead of converting degrees/minutes to decimal I directly entered the values in GCS. Meaning: my AQ config had -66.59 (66° 59') instead of -66.98 (decimal converted value by AGC tool) for inclination and 1.31 (+1° 31') instead of 1.52 for declination.

Can this be the reason?

Jens

[DUKE40]

Hi Jens,

did you have a 3D Fix for your GPS? GPS led solid blue?

[bn999]

Before you use any non-manual flight modes, you need to make sure that you have full control of the machine first. You should be able to enter full stick deflections without the craft doing anything silly like flipping.

Assuming you don't have any problems with the motors stalling, you likely have a PID problem. You need to carefully exercise the machine with a uSD card installed. The resultant log will tell you everything you need to know.

[JensKa]

DUKE40, GPS led was as solid blue as it could get. So it had a 3D fix.
bn999, good point. During that hover I was only making small stick corrections, no full deflections.

My plan is to repair the copter as it is, leaving the AQ unchanged. After having done that I will test hover it again *WITH* an sd card inserted (that lesson is learned now) and post my findings here.

Now I am waiting for replacement parts.