Hi Folks,
I'm strugling with my 3DR quad. And I think it has to do with the PID settings. When the AC goes up, it has no problem. Then hovering is a bit of a problem. As soon as I start correcting, the AC tends to loose thrust en some big woble movements end up in a uncontrolled landing most of the times.
I'm having the 880 KV motors and 12x4,5 props on it. I have no quick oscillation in the frame, that's stable. Nevertheless my longest flight was about 15 secs and already 6 props gone...
Can someone help me?
Replies
Hello Jeroen,
I live in South Carolina, was born in Illinois, grew up in Florida.
My travels have been mostly with my employer(s) - Picker-->Marconi-->Philips (same job, different names)
This morning, another idea occurred to me to try:
This would be the same as a test stand yet no altitude and full system loading. If the AC is well behaved, it would simply run the motors until the battery is exhausted.
The fact that the AC hovers well, initially, suggests the PIDs are fine and a power/loading issue may be at fault.
Another possibility is a dampening oscillation build up...possible but not proven yet.
What battery are you using?
Is this a total 3DR kit?
Would you be able to attach a photo of the APM and wiring?
-=Doug
Is it possible to use/constuct a test stand for your AC?
This sounds like a basic system/radio problem and not a software issue.
I understand the frustration of starting up. All my start up problems were not software. I made several mistakes.
The assumption is you are running in Stabilized mode.
What radio are you using? My DX6i had to be set to fixed wing, NOT helicopter mode. During the APM configuration, I could see Ch 5 working opposite the Throttle input. Not so with fixed wing.
To confirm the reversed Elevator setting, I suspended the quad from a roof beam with two lines. With just enough throttle to make the lines slack (loose), I then tested the controls. The reversed Elev was very evident.
A test stand saves propellers!
Hi Folks,
A couple of months further and still no stable quad....... Asked many people what the problem could be but until now no magic answer.
The problem is still the same as mentioned before. It flies well for about 15 sec and then for some reason starts descending and wobles into sort of a crash.
Can someone tell me if I should log other data in order to sort this out?
I hope someone can help me, because my very expensive kit is not doing what it supose to do.....
Jeroen.
Hi Adam,
Here are some logs. For some reason I think I messed up the logged data in later log files. I can only see "RAW" in those logs. I hope you can get me back on track.
If you want me to change log settings, please tell me which ones you need and I'll try to set it up for another testflight.
Jeroen
2011-12-31 09-47 3.log
2012-02-03 09-49-35.tlog
2012-01-08 07-34 3.log
Hi Adam,
I send you some logs. Mainly they all had the same result. I hope you can do something with it.
Many thanks in advance!
Jeroen.
logs.rar
Hi Folks,
I'm getting pretty desperate now. I tried all your adviced settings and I see a lot of difference in the behaviour of the AC. So in general I'm convinced that settings is very importand to get it stable. But I'm realy wondering if the STAB and RATE settings have something to do with the problem I'm having.
I give throttle and the AC rises up for let's say 5 meter. Very stable, no oscillation.
When I don't move the pitch/roll stick it hovers also pretty stable.
But of course it slowly drifts away due to minor winds or so.
That's the moment where problems arise.
I correct the AC and from that moment it looks like throttle reduces. The AC looses altitude, so I give small extra throttle.
The AC keeps on loosing altitude and I keep on increasing throttle, but I cannot notice any increasement of RPM on any of the rotors. Finaly the AC wants to almost flip into one direction and an uncontrolled landing is a fact. Sometimes props die as well.
I checked all prop directions, left/right forward back etc. yaw. all is fine as long as handheld or the first 7 secs of my flight.
Can someone please advice me what to do??? I'm having the AC now for three months and my longest flight was about 15 secs. So any help is highly appreciated.
Jeroen, could you provide us with the following details:
1. Wich software did you opload to the board? did you use the planner to upload the software?
2. Which version of the planner are you using? It look like you have an old planner and are missing some fundamental parameters. (ie. RATE_D) if so you can download the new one from here : Planner
If for any reason you have an old software update the planner (actual planner is 1.1.48) and upload the latest firmware.
If you want to wait the next release (very promising) then try to change your params in this way:
STAB_P 4
STAB_I 0.02
RATE_P 0.12 or even higher
RATE_I 0
Having only P on both control loops like you will never work good.
Hope this helps,
Emile
If it is large oscillations, try lowering your Stab_P. Seeing a video of your flight really helps...
You might also need to slightly raise your Rate_P.
oh dear. What gains are you using? Can you describe your system in detail?
BTW, we're pushing to get out a big patch this friday that should help. but your issues sound configuration related.
Jason