Strong Wind RTH

[BroomRider]

That's completely consistent with my experience. I get the "strong wind" warning on my Mini-1 and Mini-SE all the time, and that's the message I get.

But I once had a low signal RTH directly after getting the high wind warning, and the little SE came home fine.

The only weird thing about it was that on the return home, it was flying into the wind, sideways, with the flight path 90º to the right of the direction that the nose was pointing...

I had something similar to that happen on the way home, after getting a couple of high wind warnings, & at the same time, I noticed some odd very brief "interference bars" on the right side about midway down in my RC display (they almost looked like the edges of a prop spinning), & I noticed that roughly about each time I got the high wind warnings. I can grab some screenshots from the record if needed.

I was using 'screen record' at the time, & not video record in the drone, so I can't say if those same interferences were recorded on the memory card of the drone too.

I chalked that up to the gimbal tilt limit being reached & that creating the error, as my M3P drone was pitched over at roughly a 45-degree angle against the wind from the right & the display recorded a tilted horizon too.

After I reduced my altitude & began flying back home, the wind was still pretty stiff, & I noticed that my drone wasn't flying in the direction that the camera was pointed; it was "crabbing" to the side, although not at a 90-degree angle. I adjusted my heading to compensate & made it back home safely.

It was after I did the usual firmware check before my next flight, & finding nothing new, I noticed an "incompatible gimbal data" message, & tried to do an auto-calibration which failed to clear the message, & a recommendation from another member here to do a firmware refresh, which worked.

Now, any time I see that error message, I refresh the firmware & so far that's worked each time.

I've not been flying in such high winds since & haven't seen a repeat of that issue.

I can't comment on the High Winds RTH topic as I've either flown home manually, or had a successful RTH.

 

[frcaloy]

That's rather unusual.
Do you have the flight data for that flight ?

Yup. It's in the App's flight records

 

[frcaloy]

Got it. This is the flight record where the ground speed was halved at around 30% battery level. Mini 2

Correction: I was around 70 % battery levels.

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[Meta4]

Got it. This is the flight record where the ground speed was halved at around 30% battery level. Mini 2
Correction: I was around 70 % battery levels.

I can't see anywhere in that flight where the flight speed was halved.
The only time that flight speed wasn't normal full speed was when you only pushed the right stick forward for 2.5 sec at 6:36.3 and the drone didn't have any time to accelerate to full speed.

 

[frcaloy]

I can't see anywhere in that flight where the flight speed was halved.
The only time that flight speed wasn't normal full speed was when you only pushed the right stick forward for 2.5 sec at 6:36.3 and the drone didn't have any time to accelerate to full speed.

Please check the 13:35 portion onwards when there was full forward right stick and low speed

 

[Meta4]

Please check the 13:35 portion onwards when there was full forward right stick and low speed

The flight data ends at 10:29.8.
Perhaps you posted data from the wrong flight?

 

[frcaloy]

The flight data ends at 10:29.8.
Perhaps you posted data from the wrong flight?

Maybe. Will check.

 

[frcaloy]

Maybe. Will check.

Sorry. Posted wrong flight data. Will post correct data momentarily.

 

[frcaloy]

Posting the flight log. Sorry for posting the wrong flight log.

DJI Flight Log Viewer - PhantomHelp.com

 

[Meta4]

Flew the Mini 2 a few minutes ago. Took off around 1715. Sunset is 1745. Just noticed that the ground speed of the Mini 2 halved when battery was at 30%

Is this normal? I remember Yorkshire_pud saying that at low battery levels, the software starts limiting the power to the motor.

DJI will restrict the power output of the motors to prevent you from putting too much load on a very low battery and causing the drone to fall from the sky.
I can't remember at what battery level that happens, but it's when the battery is very low, much lower than 30%.

In the flight data you posted the max speed is slow when the drone is flying toward the NE and pushing against a headwind.
That is completely normal.
Swim against a current or fly against a headwind, and your ground speed will be reduced by the speed of the current you are fighting.

You can see this in the flight data at 7 minutes and 14 minutes.

 

[frcaloy]

DJI will restrict the power output of the motors to prevent you from putting too much load on a very low battery and causing the drone to fall from the sky.
I can't remember at what battery level that happens, but it's when the battery is very low, much lower than 30%.

In the flight data you posted the max speed is slow when the drone is flying toward the NE and pushing against a headwind.
That is completely normal.
Swim against a current or fly against a headwind, and your ground speed will be reduced by the speed of the current you are fighting.

You can see this in the flight data at 7 minutes and 14 minutes.

The timeline 13:30 onwards is the flight segment in question. Full forward right stick and half the speed.

 

[Meta4]

The timeline 13:30 onwards is the flight segment in question. Full forward right stick and half the speed.

Yes .. because the drone was flying against a headwind, just as it was at 7 minutes as well.
This is perfectly normal.

 

[slup]

.. because the drone was flying against a headwind..
This is perfectly normal.

Nah ... this isn't normal at all.

If looking into the applied elevator command relative horizontal speed & achieved pitch angle some odd thing's stand out that at least doesn't directly have to do with flying into a headwind. Have seen this phenomena once before but we couldn't explain it ... & that the Mini 2 lack the possibility to investigate the .DAT logs doesn't make it easier.

If looking at a full longer elevator command (black dashed graph) happening between 826sec (13m 46s) to 849sec (14m9s)(have put a red frame around the period in the chart) we see that the drone initially increase it's speed (blue graph) up to about 14,5mph... this with a pitch angle (green graph) of -24,9 degrees... but there the pitch angle suddenly decrease rapidly & kind of step wise ending up on -16,5 degrees. This pitch change happens uncommanded & wind doesn't make a drone pitch up. In the end it's the shallow pitch angle that decrease the horizontal speed down to 8,8mph as a minimum.

The only explanation I can give is that the rear props maybe doesn't generate enough thrust to pitch the Mini 2 down according to spec.

 

[frcaloy]

Nah ... this isn't normal at all.

If looking into the applied elevator command relative horizontal speed & achieved pitch angle some odd thing's stand out that at least doesn't directly have to do with flying into a headwind. Have seen this phenomena once before but we couldn't explain it ... & that the Mini 2 lack the possibility to investigate the .DAT logs doesn't make it easier.

If looking at a full longer elevator command (black dashed graph) happening between 826sec (13m 46s) to 849sec (14m9s)(have put a red frame around the period in the chart) we see that the drone initially increase it's speed (blue graph) up to about 14,5mph... this with a pitch angle (green graph) of -24,9 degrees... but there the pitch angle suddenly decrease rapidly & kind of step wise ending up on -16,5 degrees. This pitch change happens uncommanded & wind doesn't make a drone pitch up. In the end it's the shallow pitch angle that decrease the horizontal speed down to 8,8mph as a minimum.

The only explanation I can give is that the rear props maybe doesn't generate enough thrust to pitch the Mini 2 down according to spec.

View attachment 155766

Finally! I experienced this twice before. Assumed it was due to headwinds.

 

[slup]

Finally! I experienced this twice before. Assumed it was due to headwinds.

You could try to change the props to a new set ... & if this happens again, try to turn around and see if the craft can achieve full speed flying backwards, if so ... that indicate flattened rear props that can't generate enough thrust.

 

[frcaloy]

You could try to change the props to a new set ... & if this happens again, try to turn around and see if the craft can achieve full speed flying backwards, if so ... that indicate flattened rear props that can't generate enough thrust.

I could change the rear props with the reserved props that came with the drone. It doesn't explain the change in pitch angle though.

 

[Meta4]

Finally! I experienced this twice before. Assumed it was due to headwinds.

Headwinds are a factor too.
It only happened when flying in one direction.
You had no trouble flying in other directions.

 

[slup]

What makes the Mini 2 not pitching down according to spec is most probably due to that not enough thrust is created... this can have 2 reasons, either the motors doesn't rotate fast enough or the props doesn't perform as they should. If it's the later it can be due to that the props have been deformed, this make them generate less thrust which in turn forces the motors to spin faster... until they reach max rpm's, & if the drone pitch isn't achieved by then the pitch will be less which equals to a slower horizontal speed.

This was what plagued the Mini 1's. rear props...

This will be more likely to happen in a headwind as the drone there need to utilize max tilt angle... with a tailwind the drone more likely try to brake to not exceed the max speed for the flight mode... it doesn't need to pitch down so much.

 

[frcaloy]

What makes the Mini 2 not pitching down according to spec is most probably due to that not enough thrust is created... this can have 2 reasons, either the motors doesn't rotate fast enough or the props doesn't perform as they should. If it's the later it can be due to that the props have been deformed, this make them generate less thrust which in turn forces the motors to spin faster... until they reach max rpm's, & if the drone pitch isn't achieved by then the pitch will be less which equals to a slower horizontal speed.

This was what plagued the Mini 1's. rear props...

This will be more likely to happen in a headwind as the drone there need to utilize max tilt angle... with a tailwind the drone more likely try to brake to not exceed the max speed for the flight mode... it doesn't need to pitch down so much.

Is it because of the props holder? Does the prop holder deform the rear props.

 

[Elthree]

Is it because of the props holder? Does the prop holder deform the rear props.

It can (depending on the specific prop holder you're using).
With the one most commonly seen, it may depend on where you position the props before cinching the top strap down.
Ideally not though.