Thread for TomB67

[TomB67]

This was the wind speed, 17km, it should not have affected it, I've come across in the data that signal was poor lost it a couple of times.

 

[sar104]

Doesn't RC elevator usually range from -10,000 to 10,000? The baseline here seems to be at 1024 and doesn't really change from that throughout the flight. The maximum pitch of 25* is never attained until RTH is initiated.

It looks like there was plenty of stick input prior to RTH. In terms of pitch and roll - remember that you need to consider total tilt angle (i.e. nutation) and both elevator and aileron inputs:

 

[TomB67]

Doesn't RC elevator usually range from -10,000 to 10,000? The baseline here seems to be at 1024 and doesn't really change from that throughout the flight. The maximum pitch of 25* is never attained until RTH is initiated.

I'm not sure, I'm only new to all of this but all I can say is that there was something definitely not right I hit n slid the RTH about 5 times before the auto RTH cut in, it doesn't even show up in the logs. I don't have a leg to stand on and when I get another if I do I just won't trust any settings in the whole system. Thanks for all your help I really do appreciate it, was going to take it on our long awaited holiday to the US, even registered it with the FAA, that was all a waist of time.

 

[TomB67]

It looks like there was plenty of stick input prior to RTH. In terms of pitch and roll - remember that you need to consider total tilt angle (i.e. nutation) and both elevator and aileron inputs:

View attachment 35598

Yes I was frantically trying to get it home. it was all non responsive.

 

[sar104]

View attachment 35597

This was the wind speed, 17km, it should not have affected it, I've come across in the data that signal was poor lost it a couple of times.

The wind was much stronger than that coming back:

Airdata UAV - Flight Data Analysis for Drones

 

[sar104]

Yes I was frantically trying to get it home. it was all non responsive.

No - look at the graph above - it was responding properly.

 

[TomB67]

Yeah I figured that out once I downloaded it (see my post #8). Plenty there for to figure out what happened.-CF

I think I have enabled permissions, here is the link below,

Airdata UAV - Flight Data Analysis for Drones

hope it works

 

[TomB67]

Amazing how the story and the logs can differ. Just how windy out there was it? I think the first thing to mention was how far out the bird was.

The bird went out to 1400mt over water with no wifi interference and a clear line of sight.

 

[TomB67]

Thats the thing, why didn't it RTH when I first hit it? That is the baffling part. I hit and slid RTH 5 times with no responce.

 

[sar104]

Thats the thing, why didn't it RTH when I first hit it? That is the baffling part. I hit and slid RTH 5 times with no responce.

It went to RTH at 553 s, as shown below.

 

[Simmo]

@sar104 Bud at 553, is that a change in direction there? I tried displaying the heading in CSV but it just says '1'. What do I display to show heading?
My reason for asking is that earlier I too put a graph together that came out very similar to yours. The pitch and roll I had seperately though. Its only when RTH is triggered that the aircraft tilts right over, before that it was quite level. Is that the change of direction into the wind??

 

[RayOZ]

In hindsight, he could've cancelled RTH, turned northwest and fly towards the park/oval, then drive down to retrieve. Also, it would've helped if he reduced altitude.

 

[Simmo]

In hindsight, he could've cancelled RTH, turned northwest and fly towards the park/oval, then drive down to retrieve. Also, it would've helped if he reduced altitude.

Too right RayOZ, I've said it before... plan B!

 

[sar104]

@sar104 Bud at 553, is that a change in direction there? I tried displaying the heading in CSV but it just says '1'. What do I display to show heading?
My reason for asking is that earlier I too put a graph together that came out very similar to yours. The pitch and roll I had seperately though. Its only when RTH is triggered that the aircraft tilts right over, before that it was quite level. Is that the change of direction into the wind??

At 553 s it goes from stationary, i.e. holding position with no stick inputs in P-GPS mode, to returning under RTH. Hence the distance from homepoint starts to decrease after holding constant prior to that.

 

[Simmo]

At 553 s it goes from stationary, i.e. holding position with no stick inputs in P-GPS mode, to returning under RTH. Hence the distance from homepoint starts to decrease after holding constant prior to that.

Ahhh ok.. I assumed, wrongly, that the AC was still moving away from the RC . Cheers mate!
Still can we tell the nose direction from the logs?

 

[sar104]

Ahhh ok.. I assumed, wrongly, that the AC was still moving away from the RC . Cheers mate!
Still can we tell the nose direction from the logs?

Certainly - that's the logged IMU yaw. Its heading does change at 553 s as the RTH aligns the aircraft to face the home point (73°).

 

[Simmo]

Got it. Cheers.

 

[MavicCF]

It looks like there was plenty of stick input prior to RTH. In terms of pitch and roll - remember that you need to consider total tilt angle (i.e. nutation) and both elevator and aileron inputs:

View attachment 35598

Ah ok, that makes sence, tying the pitch/roll and elevator/aileron together certainly makes it look cleaner. Not nearly as much of a mess of lines everywhere. Thanks, will certainly do that in future. -CF

 

[TomB67]

@sar104 Bud at 553, is that a change in direction there? I tried displaying the heading in CSV but it just says '1'. What do I display to show heading?
My reason for asking is that earlier I too put a graph together that came out very similar to yours. The pitch and roll I had seperately though. Its only when RTH is triggered that the aircraft tilts right over, before that it was quite level. Is that the change of direction into the wind??

That finding is pretty interesting, DJI have told me that they have researched the data sent and say that I was flying it in "high winds" which they claim is substantiated by saying the bird was tilted well before the RTH. Plan B mentioned would have been excellent, except for the fact that I lost all control over the drone well before the RTH kicked in and wasn't able to change any direction or control the height. Once the RTH kicked in, honestly I was just relieved it was coming back and didn't want to risk mucking up the return. I've watched hundreds of flights on YouTube etc before I even took it out of the box and people were flying in higher winds than I had with no trouble at all. Just so disappointed I've lost my baby. BIG thanks to everyone who has done all this work to help me.

 

[sar104]

That finding is pretty interesting, DJI have told me that they have researched the data sent and say that I was flying it in "high winds" which they claim is substantiated by saying the bird was tilted well before the RTH. Plan B mentioned would have been excellent, except for the fact that I lost all control over the drone well before the RTH kicked in and wasn't able to change any direction or control the height. Once the RTH kicked in, honestly I was just relieved it was coming back and didn't want to risk mucking up the return. I've watched hundreds of flights on YouTube etc before I even took it out of the box and people were flying in higher winds than I had with no trouble at all. Just so disappointed I've lost my baby. BIG thanks to everyone who has done all this work to help me.

Unfortunately, after taking the aircraft up to its maximum flight altitude, you made no attempt to bring it down. The throttle was never taken below centered.



As for your comment that it was, in general, unresponsive, it wasn't, as I pointed out earlier. Looking at the elevator response, it responds appropriately to every input that you gave it:



Similarly for aileron:



And also rudder:



In regard to the wind, I posted the link to the full wind field map in post #25. You seem to be suggesting that DJI's observation of high winds is somehow in doubt. It isn't. And in the pitch and roll plots above you can see the degree of pitch and roll required to hold position during the (many) periods of no stick input.