[lee]

Hi, all
I have ATOM with 450 heli, spektrum DX6i.
The GCS settings as figure:

I found that when I switch the flight mode from Pos1 to Pos2, the servos deviated from the neutral position, while from Pos2 to Pos1, the servos would return to the neutral position.
I think I should level out my heli, so I go to the Attitude table, place my heli flat, and level out it. Now in "Rotate virtual attitude relative to board", the values of Roll and Pitch ware 0, in this case, when I switch the flight mode, the servos were very quiet. For avoid my heli drift left side, I set the value of Roll to 3, and then switch the flight mode, the servos off-center position, I have read many articals in the LibrePilot wiki and forum but can not find the result.


Could you tell me why and how to fix it, please? Look forward to your any reply.

Best Regards!

[daveapplemotors]

Try calibrating board level. Sometimes I must repeat that.

[lee]

Try calibrating board level. Sometimes I must repeat that.

Hi, daveapplemotors
Thank you very much for your reply!
Very sorry to say..., I did calibrated the FC level, I calibrated the board in flight mode1, and the servos were very flat in this flight mode, but when I switched to the flight mode2, the servos drifted. i.e. the servo's center position was different in different flight mode.
The two flight modes were all "Attitude", only different in PID parameters.
What's wrong with my calibration operation, please? Could you help me?

Best Regards!

[daveapplemotors]

Will you attach a UAV file? I don't understand yet.

And you are welcome. I hope to help.
Dave

[lee]

Okay, the uav file was attached!
Sorry for my poor English

[daveapplemotors]

If you try Rate, Rate, AxilsLock for both flight mode 1 and flight mode 2 does the swash still jump? I have a theory: Since the two flight modes are so different when they try to get to level (Attitude) you see one flight mode accomplish more than the other.

And from your UAV:
 
 <object id="0xE8EBBD48" name="StabilizationSettingsBank1">
            <field name="ManualRate" values="220,220,220"/>
            <field name="MaximumRate" values="300,300,300"/>
This means the aircraft will rotate 220 degrees / second when you try to flip. Change Manual Rates to 540 or larger. Make Maximum a little larger so the heli can correct if it needs.

            <field name="RollRatePID" values="0.0055,0.025,3.3e-05,0.3"/>
            <field name="PitchRatePID" values="0.0055,0.025,3.3e-05,0.3"/>
Bank1 is wild. It could be uncontrollable in flight. It could oscillate.

Bank2 is about half :
            <field name="RollRatePID" values="0.003,0.0065,3.3e-05,0.3"/>
            <field name="PitchRatePID" values="0.003,0.0065,3.3e-05,0.3"/>
           
And try Rate instead of Attitude until you get it flying well.

Can you get more than 2 flight modes with your DX6i? If there is a 3 position switch you can mix it with a two position switch? Maybe you can get 6 flight modes from your TX like I get from my DX7S.

good luck,
Dave

[lee]

Hi, Dave

If you try Rate, Rate, AxilsLock for both flight mode 1 and flight mode 2 does the swash still jump?

No, it doesn't jump.

I have a theory: Since the two flight modes are so different when they try to get to level (Attitude) you see one flight mode accomplish more than the other.

Thanks for your infomation, it solved my confusion. That is, for my case, the jump comes from the algorithm result of different parameters.

And from your UAV:
 
 <object id="0xE8EBBD48" name="StabilizationSettingsBank1">
            <field name="ManualRate" values="220,220,220"/>
            <field name="MaximumRate" values="300,300,300"/>
This means the aircraft will rotate 220 degrees / second when you try to flip. Change Manual Rates to 540 or larger. Make Maximum a little larger so the heli can correct if it needs.

            <field name="RollRatePID" values="0.0055,0.025,3.3e-05,0.3"/>
            <field name="PitchRatePID" values="0.0055,0.025,3.3e-05,0.3"/>
Bank1 is wild. It could be uncontrollable in flight. It could oscillate.

Bank2 is about half :
            <field name="RollRatePID" values="0.003,0.0065,3.3e-05,0.3"/>
            <field name="PitchRatePID" values="0.003,0.0065,3.3e-05,0.3"/>
           
And try Rate instead of Attitude until you get it flying well.

I will follow your suggestion, and attach the uav file when it flying well.

Can you get more than 2 flight modes with your DX6i? If there is a 3 position switch you can mix it with a two position switch? Maybe you can get 6 flight modes from your TX like I get from my DX7S.

All the switch are 2 position, I will see the product specification and try to mix them for more flight mode.

Best wishes
Lee