Ok, so I waited one more day for less wind, this time it shouldn’t have been much of a factor. ANGLE_MAX also increased to 45. Yet the new result was about the same:
This time the last message on OSD (but not on Yaapu) was “AUTOTUNE: SUCCESS”. Then the copter was not doing anything anymore, just loitering. Yes, I initiated from LOITER again - but currently I think the main problem is not the quality of the tune result but the fact that nothing is saved.
Unfortunately I still haven’t been able to get all messages displayed as text that occured while AUTOTUNE was active, neither in MP nor APMPlanner. But on OSD or Yaapu there was no indication any PIDs were saved, although I landed and disarmed while AUTOTUNE was still active.
So I compared the param files and just like last time nothing had changed PID-wise.
Before knowing that, I flew a few rounds and noticed another oddity: The craft vibrated massively when entering LOITER. Even when hovering manually at the same throttle, there was no visible shaking.
I have another wind-less day coming up, so I could try again tomorrow if I knew what to change/try. Please excuse any lack of precision, I had a bad headache all day but absolutely wanted to make some progress with this copter.
Damn, so I shouldn’t have switched from LOITER to ALTHOLD, but just landed, that’s it? I was under the impression keeping AUTOTUNE active was enough - but that probably is only true when it’s a flight mode?
In other news, I just watched some HD footage and the heavy “vibrations” that came up only in LOITER are definitely extreme yaw twitches. (But that was still without any tuning having been saved.)
I can confirm it. Just checked my last log for autotune and it never goes beyond 3/4. But like the boyz say. You have to land and disarm with out making any changes. Also if your using some form of ground station that speaks, you might not hear it say that the pids are saved. I have had a few AT’s done where the announcement isn’t done for what ever reason. However most of the time it does say so.
Ok, thanks, I think I finally got it. I was probably still confused by the wiki entry and the low/high switch flipping suggested therein.
So the correct way is to simply land and disarm, never leaving AUTOTUNE mode at all. No PID comparison etc. And 3/4 actually means 4/4, got that as well.
When the GCS announcement is missing, is there maybe still a message on OSD?
EDIT: In the wiki it says:
“If you do happen to accidentally discard a sessions AUTOTUNE values by disarming when not in AUTOTUNE, you can examine the dataflash log for the GCS messages it sent during tune and manually set them on the bench.”
If anyone could tell how to filter out these messages, I could do that right away.
At least I wasn’t the first one to be confused as threads like this prove. For me the confusion arose from the using of 2 separate switches. One can keep the dedicated “autotune switch” physically active and mistakenly think autotune is therefore active as well, while using the “real” flight mode switch to change modes before landing and disarming.
Like (if I’m correct, never tried it) the craft would remain in RTL as long as a dedicated switch (via RCn_OPTION) is active, overriding any mode change attempts.
Sure, there was a message AUTOTUNE: STOPPED on the OSD but I only saw that afterwards when I checked the recording. During the process I was just watching GCS messages on Yaapu and either missed the message there or it didn’t appear.
Is the autotune documentation still accurate? Looks like it was written for AC 3.3 and updated a few times. I too have been a little unclear on whether I have to switch out then back into autotune and land to save pids or if I could just land with autotune on and never moving out of that mode.
Fly your bird. Do one axis at a time. Use alt hold not loiter. Run the tune, when it stops land and disarm. Don’t change anything no flight modes nothing until you have landed and disarmed. The pids will be saved then. There may not be an audible announcement on your ground station. Most times there is but not always. Then do the next axis and so on.
Just a question from a noob here. What is the difference between a copter that got autotuned and one that did not?
I have never completed autotune for many reasons (bad weather all the time, not enough space, and fear it would just crash). And to me, it seems that the copter flies well, always completes the mission.
Does every copter need an autotune? And if so, can I expect better battery performance?
I would suggest an autotune not necessary but 99% of time it just improves the flying of your craft and reduces vibes which is your worst enemy as vibes lead to lots of other problems
Many thanks! And one more thing. Do you do autotune with all the equipment on the drone or is it okay without? By equipment, I mean GoPro camera, gimbal, etc.
I am not sure to be honest I think when I did my discovery a few yrs ago with the gimble and camera i did it first with them off and then with them on,I would just try it with them on but be ready at the beginning to switch back to alt hold,im sure some one else will advise
On this particular (small 4") copter, it made a difference like night and day. If you never needed it, your copters are probably perfectly suited for the AC default PIDs.
When I tried a 10" copter last year it also seemed to fly much better on defaults than this one. (I had other problems with that one, so I still haven’t attempted Autotune with it yet.)
Equipment on board is fine except gimbals. They tend to mess up the response to the AT. I usually take mine off and replace with with something fixed that weighs the same. It’s not perfect because it may not be the same dimensions as the gimbal and gopro. But it does allow me to get it tuned very well. I have one drone that has the gimbal built in and so I have to tune it with the gimbal on board and I never get a real perfect Roll tune. I am guessing the gimbal slops back and forth and throughs things off a bit.
Mind you the machine flies fine, but the logs show it could be tighter.
It depends on how it’s flying. I have two 450 size quads (different frames). One I have not run autotune, and in spite of having a vibration problem, flies great on stock PIDs. Even when I look at the logs I doubt I could make significant improvement. I have not run autotune on it simply because I like how it fly’s. The other quad (with no vibrations) flies okay, or at least safely, on stock PIDs but it really improved with tuning.
Both quads had the initial parameters set up by the spreadsheet/Alt-A, and both have had the notch filters setup.
So I guess the answer to you question is No, not all quads need auto tune, but I would always plan to do it. Given that the default values worked great for me on an old 450 frame with 9" props on 4S, tells me that if you’re flying anything too far off that then you are more likely to need to autotune.