Major Crash on 2.0.37 & 38

Just had my third major crash in two weeks.  This time took out 4 props and my receiver ....

 

I think that I at last understand the problem.

 

I have been really keen to use RTL and up to and including .37 it has been unusable for me.  The model would fly off at 45 degrees etc and the first two crashed were when I switched back to stable mode.

 

Today on .38 the RTL function was at last working for me - fly the model 100 metres away and then watch it come back to RTL position, a little meandering but other that than excellent.

 

On my third battery I tried RTL again and when it comes over my head I switch back to stable mode and just like the last two crashes, the hexa does a 180 and goes in under full power.

 

All three crashes, now with .37 and .38 happened when I switched from RTL to stable.  To do this I move my two and three position switches through Alt_hold back to stable.  I think the problem is that I am confusing the program by going between two or three modes in a split second.

 

Would anyone agree that this may be a problem and if so is there a way to ignore new mode for perhaps half a second.

Must say that before the crash this evening, I had the most fun in ages with Altitude hold, Loiter and RTL all working really well.

 

Thanks Guys.

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Replies

  • I maybe be on to something concerning the mode switches.

    I start out in stable mode, fly a bit and land. Then I switch mode to auto and then back again to stable. In doing so I have to pass all the other values/modes. When I wanted to lift off the quad had alot more power then normal. I cut back on the throttle and waited a little bit. Then it was all back to normal.

    I'm thinking that swithing between modes  needs a small amount of timeto get the loop running.

    Can someone test this?

  • 'Just a side note ... perhaps the point raised on in between modes affecting the behavior of the ardu will lend some argument in favor for the rationale put up by Pieter van Woerkom in http://diydrones.com/forum/topics/the-ultimate-modeswitch-for-my ... just a thought ...

  • Mine was already deleted as I knew it was pilot error but if I see the same behavior tomorrow I will post the log.  But maybe Philip still has his logs

  • Developer

    My thinking right now is that there is some sort of I term windup causing the flip that combined with some gyro drift and a powerful setup could cause a flip in the worst circumstances. Theoretically. I haven't run the numbers but a log would be awesome if you had one.

    Jason

  • I also tried RTL with v37 but only had to change one position to go from RTL to Stable. Had to do this because quad was flying aggresive.

    My modes are

    pos 0 stable

    pos 1 RTL

    pos 2 AH

    pos 3 Simple

    pos 4 Loiter

    pos 5 Auto

  • Developer

    Crap, That doesn't sound good and no I don't know right away what the problem is. Is the 180 a yaw or did it flip upside down? Do you have a log? What was your throttle position when it happened? Was the copter relatively still when you switched or was it moving?

    Thanks!

    Jason

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