Auto control in "loiter" stronger than manual control

I've got an issue w/ my small 250 sized copter, that I haven't noticed w/ bigger copters.. I've built a couple small ones now, and they both do this...

when in loiter, if the copter starts to move some direction I don't want it to, (because GPS drifts), I cannot overcome that movement with manual control. 

So, copter is moving to the left towards a tree.  I command full right roll, and the copter slows its left movement, but it doesn't stop.  Crashes into tree. 

this is repeatable..  It is the same on two different (tho both 250 sized) quads. 
Both have the gyro filters set to 40hz.  Both auto tuned.  Nothing else is unique about them. 

Could anyone tell me some possible causes or fixes for this. 

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  • Leonard said he'd review my logs of this issue, so here are a couple from short test flights. 

    Look at the last minute or 30 seconds of each log, because I was definitely having trouble before landing each time. 
    It seems to me like it takes a couple of seconds for my manual control to finally take priority over its auto control..
    It might be less time than that, though, because I'm about to crash in those situations, and my perception of time is probably exaggerated.  It does eventually do what I tell it to, but not with enough strength or priority, or something..

    This might be relevant while reading my logs..  I haven't really flown in months, so my inputs are not smooth..  I was causing problems by over compensating my controls... But I flew in stabilize, alt-hold, and other manual modes today, and the issue is definitely w/ loiter, and not just my flying.  Also, it was windy.

    Thanks to anyone who looks at my logs.

    • Developer

      Hi Scott,

      Do you have a video of the problem. It is very hard to look at this because GPS is having a gentle glitch with very little sign that there is anything wrong. The EKF does detect the problem and do a reset but it isn't so bad that it bailes out completely.

      I can see on the map you seem to be flying under a thick tree and I suspect that this is a big part of your problem.

      We have a change planned that will ensure a faster response to your inputs but this doesn't change the limitation that the copter is attempting to hold position based on the sensors it has available. It can't tell if the sensors are gently leading it astray (while it thinks it is stationary) and there is a wind building.

      • Ok, thank you for looking. 
        I'll post sometime in the future if I get more data (video, etc) or solve it. 

        I am under a tree, but no leaves at the moment.. 
        I've had a lot of trouble w/ t his GPS...    It drifts around a 10-20 meter area, while another GPS holds its position (or maybe 1-2 meter drift), in the same location under this tree...   

        I think I'll start there.. Even if it doesn't react to my commands as quickly as I'd like... W/ a better GPS it shouldn't be trying to drift off in random directions.

        Thanks again

        • I just tried PosHold, and it is working great...  I think I was expecting loiter to work like PosHold, and maybe that was my issue...  I don't notice it in my bigger copters, because I'm never trying to make very fast corrections w/ my big copters...

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