Inflight data logging HW+SW

Sebbi
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Re: Inflight data logging HW+SW

Post by Sebbi »

Just a quick observation, I'd like to share.

When I used logging I had cycle times of around 4600 µs ... without logging they at 3000 µs. The interesting part is that level mode feels much more controllable with the higher cycle time (and default PIDs) than with the default cycle time. It doesn't really zero back and starts drifting away faster. I tried to change the PIDs to match the behaviour of the slower cycle time, but then my battery was empty. Will try that tomorrow. It looks like some of the drift problems have their cause in the PID settings.

I am still interested in making computeIMU more accurate, but it should also be a priority to make the PID algorithms timing independent ... like described in Wikipedia: http://en.wikipedia.org/wiki/PID_contro ... ementation ... a fixed cycle time or the use of the cycle time in the calculations should solve this problem and should result in comparable PIDs.

I'll further investigate (and log) ;-)

copterrichie
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Re: Inflight data logging HW+SW

Post by copterrichie »

As we had previous noted, the I and D are tied to the cycle time. So this comes as no surprise to me but it is very good to know your confirmation of this. :)

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alduxvm
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Re: Inflight data logging HW+SW

Post by alduxvm »

Has someone implemented datalooging with OpenLog with MW dev 2014 by any chance?? I'm using r1648 and it would be really uselful if some point to me where to insert the code?? maybe in MultiWii.cpp??

And also, I have to put the openlog v3 firmware (https://github.com/phollands/OpenLog/tr ... OpenLog_v3) on my virgin OpenLog?? :P

mj666
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Re: Inflight data logging HW+SW

Post by mj666 »


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alduxvm
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Re: Inflight data logging HW+SW

Post by alduxvm »

Thanks a lot, I'm going to test Renes firwmare!!

:)

dehalo
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Re: Inflight data logging HW+SW

Post by dehalo »

I have made a modified firmware https://www.dropbox.com/s/lztm4fh8r5hfby7/OpenLog.ino?dl=0for OpenLog that creates logfiles of the flight data (including GPS) in csv format on the microSD card.
These files can easily be imported into MS-Excel.
I cannot currently exclude the possibility that it will make the FC crash.

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