This is sort of a continuation of this thread. Unable to figure out why my X8 has been so unstable, I figured I would give 3.2 a shot.
It seems quite a bit better - loiter is much more stable and I don’t have my oscillations anymore. I also did a compass calibration right before flying, which may have helped.
I still have one lingering issue, and it’s a pretty big one - I can never seem to pitch BACKWARDS in stabilize. It’s almost like my back pitch gets completely trimmed out. While trying to land it, I needed to bring it back to me, and even with full back elevator, it barely moved, and at some points actually went the opposite direction.
The logs don’t make sense to me. My full rear pitch is evident, and the AP is commanding it, but actual pitch really just never does anything. None of the motors are maxed out - doesn’t make sense to me.
I’m in real trouble as I’m supposed to take this thing on a plane to do a tower survey on Monday and it’s not looking good.
Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.
[quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
[quote=“dmurray14”][quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
Thoughts?[/quote]
Your screenshots says otherwise. Despitch and pitch should be tracking each other very closely. It is your case at all … Pitch forward and backward.
Did you check the HUD in MP ? When you move the copter, it shows the right information ?
[quote=“badzz”][quote=“dmurray14”][quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
Thoughts?[/quote]
Your screenshots says otherwise. Despitch and pitch should be tracking each other very closely. It is your case at all … Pitch forward and backward.
Did you check the HUD in MP ? When you move the copter, it shows the right information ?[/quote]
Yes, it does. If I let go of the sticks, it will level out and hover eventually. At that point, I can yaw, roll in either direction, and pitch forward exactly as I would expect. Pitching backwards is the only thing that has an issue - it will still eventually slightly pitch backwards, just very, very slowly.
[quote=“dmurray14”][quote=“badzz”][quote=“dmurray14”][quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
Thoughts?[/quote]
Your screenshots says otherwise. Despitch and pitch should be tracking each other very closely. It is your case at all … Pitch forward and backward.
Did you check the HUD in MP ? When you move the copter, it shows the right information ?[/quote]
Yes, it does. If I let go of the sticks, it will level out and hover eventually. At that point, I can yaw, roll in either direction, and pitch forward exactly as I would expect. Pitching backwards is the only thing that has an issue - it will still eventually slightly pitch backwards, just very, very slowly.[/quote]
I understand but it is not what APM sees and that might be a clue to your problem. Check the HUD in MP, it will tell us more.
[quote=“badzz”][quote=“dmurray14”][quote=“badzz”][quote=“dmurray14”][quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
Thoughts?[/quote]
Your screenshots says otherwise. Despitch and pitch should be tracking each other very closely. It is your case at all … Pitch forward and backward.
Did you check the HUD in MP ? When you move the copter, it shows the right information ?[/quote]
Yes, it does. If I let go of the sticks, it will level out and hover eventually. At that point, I can yaw, roll in either direction, and pitch forward exactly as I would expect. Pitching backwards is the only thing that has an issue - it will still eventually slightly pitch backwards, just very, very slowly.[/quote]
I understand but it is not what APM sees and that might be a clue to your problem. Check the HUD in MP, it will tell us more.[/quote]
How so? It seems to me that the logs show exactly what I saw in real life - it tracks forward pitch pretty well, but backwards pitch only gets to about 1/3 of desired.
Sorry if I’m misunderstanding, thanks for looking!
[quote=“dmurray14”][quote=“badzz”][quote=“dmurray14”][quote=“badzz”][quote=“dmurray14”][quote=“badzz”]Did not look at the logs yet but indeed the despitch/pitch seems completely out of whack.
I would double and triple check your motor rotation direction and the pixhawk arrow that it is pointing in the right direction. Check on the bench using the mp that your pitch and roll are correct as well.[/quote]
Thanks, I have done exactly that - quite a few times to make sure I’m not crazy. I don’t think anything is reversed, because I CAN fly it - roll works fine and pitch forward does exactly what I would expect, as does yaw. It will, eventually and slowly, pitch back, but it takes a lot of coaxing.
This is built off the 3DR frame, and I’m wondering if maybe “X” isn’t the right frame type? It certainly isn’t a symmetric X, but their DIY guides all say to use it.
Thoughts?[/quote]
Your screenshots says otherwise. Despitch and pitch should be tracking each other very closely. It is your case at all … Pitch forward and backward.
Did you check the HUD in MP ? When you move the copter, it shows the right information ?[/quote]
Yes, it does. If I let go of the sticks, it will level out and hover eventually. At that point, I can yaw, roll in either direction, and pitch forward exactly as I would expect. Pitching backwards is the only thing that has an issue - it will still eventually slightly pitch backwards, just very, very slowly.[/quote]
I understand but it is not what APM sees and that might be a clue to your problem. Check the HUD in MP, it will tell us more.[/quote]
How so? It seems to me that the logs show exactly what I saw in real life - it tracks forward pitch pretty well, but backwards pitch only gets to about 1/3 of desired.
Sorry if I’m misunderstanding, thanks for looking![/quote]
They should be almost identical. On your graph they have at least 10degree diff and sometimes completely diverge.
Look at first graph copter.ardupilot.com/wiki/common … sing-logs/ . it should look like this
Just went back out with it again, making note to watch the HUD. At no point did read incorrectly, it tracked what I saw correctly. Same problem though, back pitch is completely unpredictable.
Even tried switching the frame type to ‘V’ since the 3DR quad frame isn’t really a symmetric X. Didn’t seem to make a difference.
Might be a dangerous suggestion, but to further focus where the problem may be, may I suggest setting AHRS_ORIENTATION = 12 (meaning Pitch 180) and giving it a test without changing any hardware config at all, keeping in mind that pitch forward requires backwards stick and vice versa? If the problem reverses sides, then you know it’s a fault with the APM. If it remains on the same side, then you’ll know for sure it’s just a hardware problem.
Hmm…that’s a very good idea. I’m not sure if I trust myself flying it completely backwards, especially since it needs to be pretty high up. But at this point I don’t have much to lose…
Setting pitch 180 should leave your bank left/right and yaw left/right the same, just swaps pitch forward/back. You can probably invert the pitch on your transmitter so the controls would feel normal too.
Actually on second thought, maybe setting yaw to 180 would be best (AHRS_ORIENTATION = 4) so the apm doesnt get confused with backwards z-axis data. Just fly it backwards or invert your transmitter settings for roll and pitch.
Please try doing an autotune. You might also pick up the 2014 X8 frame - it has better geometry. Increase RATE_PIT_IMAX to 2000 or so. Try to balance the copter better.
I think you’re mostly just severely undertuned. Do autotune with no payload or loose mass (gimbals).