Good day guys, I’m amateur drone builder, I’ve build few drones and decide to build much bigger, X11 Max hobbywing, and i came to a problem, what ever I do, my arms is shaking, I can make lower arms shake even with changing filter or pids, frame aluminium. I wondering, what’s the problem, Because It’s anoying to be outside and change same always, so maybe you guys have some ideas what i can implement into this drone?
All frames have some natural resonance frequencies, after it’s crossed vibrations are reduced. Increasing frame stiffness helps by moving it higher where it’s easier to filter. Good filtering and lowering PIDs might help.
It’s possible to reduce PIDs on landed craft with
ATC_LAND_*_MULT
Thanks, so basically arms starting to woble when its just armed, when just armed it wobles not soft, after it take off the shake little bit less. I’ve been tryed that thing thanks for your time! Tested high pids low pids, kinda same, too high shake more, too low unflyible haha
You need to setup PIDs good for flying and lower them with previously mentioned parameters. Playing with MOT_SPIN_MIN and MOT_SPIN_ARM might also reduce idle vibrations.
Logs of the flight might help to evaluate your tune.
Hello Hendry, I am not an expert but still I have my thoughts.
Is the frame designed by you or is a commercial kit?
If it is designed by you describe and show the design here to the long term experts.
In most cases it is better to work on a root cause of a problem itself and not to overcome the problem by fighting against only the symptoms. This is only good on the final stage.
Well mot spin and arm is like in documentation, dead zone +2 i would add logs little bit later later in evening
well its designed by me, i have few uav with x9 max system with same frame like that, typicly the same, arm lenght and tube size different. but principle stays same.
Post a link to a .bin flight log.
Hello, I adding few files, there should be made changes, I will start from 0 right now, so if you guys want to join this project to teach or help, I would appreciate it. I been trying to make arms stronger with some tube in back and front, from left to right motor. But it still vibrate. thanks for your time guys. https://www.filemail.com/d/hediozpcobrmzei
Looking at one log 42-37 I don’t see much to complain about. The rate filters are too low, set them at 10Hz. How did you arrive at the Rate Pitch/Roll P&I values? They look low for a craft this size. I see you have added some Landed gain multiplier, so that’s good. I suppose you may have to play around with those values to further reduce pre-launch vibration. There is no current logging which can be useful.
The configuration for logging for the notch filter with that Flight Controller is this:
INS_LOG_BAT_MASK,0
INS_LOG_BAT_OPT,0
INS RAW,LOG,OPT,9
Make another hover flight after setting these and you will want to use Multi-source with a lower bandwidth (try 8Hz).
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You need to fix voltage and current monitoring,
review or disable using built in compass #3,
not sure about MOT_THST_EXPO on this motors, some of hobbywing comes already linearised, maybe someone more experienced can clear this,
if I use datasheet provided reference I get something like this
Do this motors have CAN signal interface?
Hello mike, I see wires, green red and yellow, I tried to put on to can interfance, hobbywing writes that it should be it, but they disapeared for a while so I’m not sure… would you help me to put it top can interefence? I really wanted to do that to see esc telemetry, but I failed.
Hello, so update on flights, I’ve been outside, tested flights, stareted from scratch, I put @dkemxr log option, I’ve made autotune, looks like drone working not bad at all but axes still vibrating, sometimes more sometimes less, but I never got where it’s not vibrating at all. tryed a lot of things, but nothing helped. So maybe you will have ideas ? I made some settings, some swaps, played with mot_spin_arm and etc. Failed. after autotune its vibvrating even more, so I adding todays files, I took not one or two, check modified date, and there will be by sequence from stasrt to end. Same problem, axis vibrating…. https://www.filemail.com/d/rymjyzftalcqruy
Post one or two with a description of each. Few if any reviewers are going to go thru 8 log files.
Hey, here is 3 files, before autotune, autotune file, and after autotune. https://www.filemail.com/d/vqdtsjmrdqopogv
You mean 3 files, or 34 files?
fixed, thanks for your observation
The notch filter looks good. General attitude control isn’t bad but there is some overshoot. The fix for this is usually to increase the Rate Pitch/Roll D-term. I don’t think Auto Tune is doing the best job here but you could try increasing the aggression to 0.1 and run it again. The Rate Pitch/Roll P&I terms seem too low for a craft this size but it has a relatively high thrust:weight we don’t often see in a 48" propped quad so it’s likely due to that (Auto Tune result).
If you don’t want to continue monkeying around with Auto Tune set the Rate Pitch/Roll D-terms to .008 and the P&I terms to default (0.135) and see how that looks and feels.
BTW-How is the Flight Controller mounted?
But still how about arms? They still shaking a lot. I willl try tomorow and i will post instantly. My FC mounted like this. I will try to swap settings but the higher D the more shaking in arms.
I would get rid of that and “hard” mount it to the frame.
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