[SystemsGuy]

Gents - couple of questions.  Took a CC3D I had sitting in an unused quad frame and popped in into a dollar tree foamy wing.  Flys really well, couple of minor things that are doing my head in.

1] I wanted to use Attitude / Rattitude for emergency recovery, and possible as a trainer mode for SWMBO.  It's working pretty well, but I get oscillations at higher speeds.  I think it's pitch, but hard to tell for sure.  I played with Kp for Attitude on TxPID, but all that seems to do is to limit the throws?  Eg lowering Kp on Attitude seems to give me much less command authority.  Is that expected?

2] For the above, I assume I need to tune the Rate PID's to get rid of the high speed oscillations - is there a good methodology for doing this with a fixed wing?

Thanks!

[Anonator]

Same problem here... At low to mid speed my plane is on rails pitch wise, but at speed it "dolphins"

[hawkview]

I have revo on my wing, first you will need to make sure you have little vibration from the prop and motor, next put the vibration damping pad on fc, next use tpa, next increase vibration filter.

Follow the step doing one thing at a time till you get where you like

With planes you need them to fly well before you add fc control.

How this help

[liftbag]

Gents - couple of questions.  Took a CC3D I had sitting in an unused quad frame and popped in into a dollar tree foamy wing.  Flys really well, couple of minor things that are doing my head in.

1] I wanted to use Attitude / Rattitude for emergency recovery, and possible as a trainer mode for SWMBO.  It's working pretty well, but I get oscillations at higher speeds.  I think it's pitch, but hard to tell for sure.  I played with Kp for Attitude on TxPID, but all that seems to do is to limit the throws?  Eg lowering Kp on Attitude seems to give me much less command authority.  Is that expected?

2] For the above, I assume I need to tune the Rate PID's to get rid of the high speed oscillations - is there a good methodology for doing this with a fixed wing?

Thanks!

I have no experience with airplanes, but you have to play with inner loop PIDs to get rid of high speed oscillations. You can play with TxPID. First, you have to work with Pitch and Roll Proportionals. if you will be able to turn off the oscillations by reducing the P-term value, then you might consider to increase the value again and activate the TPS.

[liftbag]

Same problem here... At low to mid speed my plane is on rails pitch wise, but at speed it "dolphins"

This is a different problem compared to one of the thread opener.
It's very likely that you will solve by increasing the Pitch inner loop I-Term (Integral).

[SystemsGuy]

I have revo on my wing, first you will need to make sure you have little vibration from the prop and motor, next put the vibration damping pad on fc, next use tpa, next increase vibration filter.

Follow the step doing one thing at a time till you get where you like

With planes you need them to fly well before you add fc control.

How this help

Thanks for the suggestions - both the prop and the motor are pretty well balanced, and the wing flys fine with the F/C in manual mode.  I don't have any foam / damping pad on the F/C - are you saying that on a wing vibration is more of a problem than on a multirotor?  I ask as I've never insulated / damped my F/C on my multirotors.  Also, which vibration filter are you referring to?  The "Gyro Noise Filter"?

I have no experience with airplanes, but you have to play with inner loop PIDs to get rid of high speed oscillations. You can play with TxPID. First, you have to work with Pitch and Roll Proportionals. if you will be able to turn off the oscillations by reducing the P-term value, then you might consider to increase the value again and activate the TPS.

Thanks - I'll give it some more time this afternoon assuming the temperature and wind both drop a bit!   When you manipulate "P" via TxPID, are you simply reducing it until the oscillations are gone, and then increasing "D"?