Solo Crash on Camera Flash

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- John Oberholtzer > Phillip Schmidt July 2, 2015 at 1:55pm
  
  One of the reasons to implement a Kalman filter, or EFK, is to integrate all of your position data (GPS, accelerator, barometer) and filter out erratic data. In your scenario #2, if you lose a GPS sat or one of the sats gives bogus data, it should be filtered out and not totally destroy your vehicle position.
  
  That was why I was originally questioning if 3dr had implemented something such as the EFK to compensate for erratic input.
  
  To get FAA certification for the avionics software I used to work on, we had to prove we could drop X number of inputs (GPS, altitude, INS, etc) and still maintain accurate position, speed, heading. Losing one or 2 GPS sat signals after initial position was established was no big deal
- Phillip Schmidt > John Oberholtzer July 2, 2015 at 5:22pm
  
  Also, keep in mind that these things are flying off of $2 sensors borrowed from cell phones. They are multiple orders of magnitude noisier than even the poorest quality sensors used for commercial flight. The time that a drone can fly on INS is measured in seconds before the accumulation of error starts causing significant position deviations.
- Phillip Schmidt > John Oberholtzer July 2, 2015 at 3:19pm
  
  Without looking at the logs, it quite possible that you were marginal in satellite count to begin with. Once one dropped, the position could have shifted due to the poor geometry of the remaining ones. Initially the EKF would reject the position shift and fly off of the INS. IF the new position is reported consistently for long enough, the EKF will "believe" the new position is reliable. At that point it would physically shift position to accommodate the new data. Again, this is conjecture in relation to your scenario, but it is consistent with the way this EKF works.
- Darrell Burkey > John Oberholtzer July 1, 2015 at 6:18pm
  
  I don't know what version of Arducopter is in the Solo but Arducopter does use Kalman filters. There are some very clever and qualified people writing the code and this is an area they have spent a fair amount of time on.
- John Oberholtzer > Darrell Burkey July 1, 2015 at 9:42pm
  
  Please don't get me wrong, I have no doubt that clever and qualified people are writing the code.
  
  I'm just basing this observation on my personnel experience between my Phantom and Solo. My Phantom, in GPS hold, seems to drift alot initially. After it's been flying couple of minutes, it seems to continue to decrease it's deviation over time.
  
  The Solo did not seem to decrease it's deviation over time. It holds within 6 feet or so, but it did not seem to improve during the flight.
  
  I have no empirical data to prove or disprove my personnel observation.
- Ken Nelson > John Oberholtzer July 1, 2015 at 9:50pm
  
  Mine has been rock solid very little deviation and that is why we were so surprised when it just took off. Of course 1+ hours is probably not much time to make much of a statement but we were very comfortable standing right next to it. The little blades aren't nearly as fearful as my 80's Hirobo Shuttle's!
- Craig Issod > John Oberholtzer July 1, 2015 at 5:58pm
  
  Makes perfect sense. To we laymen that might be expressed as "it's not as smart as it could be" or "it doesn't have the real secret down of combining all the various onboard sensors to come up with the best solution".....or something like that.
  
  Here is a post from over 2 years ago indicating that type of filtering on an earlier model of quad.
  
  http://www.rcgroups.com/forums/showpost.php?p=24451035&postcoun...
  
  Would such a filter be automatically in the OEM GPS module? Or does it have to be tailored perfectly to the combo of sensors that the particular machine uses?
  
  RC Groups - View Single Post - DJI Phantom Quadcopter
  
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John Dennings July 1, 2015 at 8:32am

Very interesting links ...

Highly doubt this can happen on the Solo, for something like this to occur the chip has to be exposed to ambient light. And that's assuming there's the same or similar chip in the Solo that would exhibit the sort of behavior occurring with the u16 on the Pi. Should be easy enough to test, though.

Now on a Linux copter running Ardupilot on an exposed Pi board, on the other hand ... In that case the copter would instantly crash.

Btw, always a good idea to cover exposed boards anyways. It's been confirmed that even sun light can wreak havoc on the barometer if it hits just right, say when flying on a cloudy day with a sudden break in the clouds...
Omer July 1, 2015 at 6:46am

Hello,

I am just curious about if camera flash causes this like on raspberry pi. Anybody confirm?

https://www.raspberrypi.org/xenon-death-flash-a-free-physics-lesson/

http://www.cnet.com/news/raspberry-pi-2-camera-shy-when-hit-with-ce...
Craig Issod June 30, 2015 at 5:55am

Expert quad Pilot with years of R/C and many dozens of hours in real planes (getting his license soon).

Start at 32 minutes in. He's good at describing the situations that many seem to be experiencing.

https://www.youtube.com/watch?v=MapiklR_9qg&feature=youtu.be

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3DR SOLO

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