DJI mavic 3 pro erratic flight issue going forward

[charliebicks]

Dear community,

When I fly my drone in a straight line forward it periodically flutters upwards and to the sides as in the video.

To the sides and to the rear it does not do this!

My input is only to pitch forward. I have a video which shows this, but I can't see how I can upload?

 

[msinger]

I have a video which shows this, but I can't see how I can upload?

Upload it to YouTube and share the link here.

 

[charliebicks]

Upload it to YouTube and share the link here.

I'm on it. it'll be here in 5

 

[charliebicks]

Thar yu goes

Dear community,

When I fly my drone in a straight line forward it periodically flutters upwards and to the sides as in the video.

To the sides and to the rear it does not do this!

My input is only to pitch forward. I have a video which shows this, but I can't see how I can upload?

 

[msinger]

Do you have the TXT flight log from that flight? If so, please post that here as well.

 

[charliebicks]

What is that and where do I find it? Thanks.

 

[msinger]

See the instructions here.

 

[charliebicks]

That's very good instruction, tah.

Here's the link to your website with the data

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

There's a fair bit of flying there, but generally when i am flying - pitching forward - this phenemoena occurs.

The video I took occurs at the beggining of my flight.

 

[slup]

...Here's the link to your website with the data

Here is a 6sec period just in the beginning of the flight that clearly show the issue...

During this period the throttle remained neutral but the vertical speed fluctuate (negative=ascend, positive=descend)... this results in a gradual height increase.




During the same period we have a full elevator input as the only stick command... this results in major instabilities in both the pitch & roll axis and the drone doesn't come even near to the specified heading speed according to spec. No braking are logged either so this doesn't seem to be a OD issue either... it's mainly the forward elevator command that starts the issue off... this repeats in several places in the log.




This behavior could be due to that the rear corners doesn't create the correct amount of thrust... try to put on a new fresh set of props all around & make a test flight & see if that change anything.

 

[Yaros]

Clean your OA sensors first of all. Check if this issue also happens in Spot mode to rule out obstacle avoidance issues.
Check if your props are fine, because I see some thrust issues in the log.

 

[charliebicks]

Thanks very much to both of you. I will try those things later this evening, today, and post here.

I'm not sure which ones are the OA sensors (infrared?) and also how to put it in to Spot mode (and what is spot mode).

 

[CaseyK]

Sport mode.

 

[charliebicks]

So I flew the drone. In sport mode and cine mode, no flutter. Turned the obstacle avoidance off and now no flutter in normal. So it was that simple…

But I can’t figure out why the obstacle avoidance is triggering.

I took photos of the sensors.

Perhaps it is the sensor with the red arrow, as I can see that sensor has a chip on it.

Is this an infrared sensor or what? And the blue sensor, what is that? Is that the vision sensor for landing?

I have had a few crashes as you can see, but this phenomenon has only been happening recently. I crashed maybe 150km of flight ago. This phenomenon has been happening for maybe the last 20km

 

[gary49]

I sometimes get the same thing when I first take off and fly over snow. According to the manual, flying over snow or water, or other featureless, terrain can cause the obstacle avoidance sensors to function erratically. I get the same results with the original Mavic three, and the Mavic three Pro. It only happens when the obstacle avoidance sensors are active, which is why you don’t see this when you put it in sport mode. Also, it only happens when I first takeoff. After a minute or so everything works normally. I think the problem is you are flying over water, which is a fairly featureless terrain. On my drones, I set them to stop upon sensing an obstacle instead of trying to fly around it. I bet if you sent your drone in the same mode, yours will act like mine does, and instead of flying left, and right and up and down to avoid imaginary obstacles, it will perform a series of accelerations and stops, all in a straight line until it all settles out. Flying over such featureless, terrain, is driving the obstacle, avoidance sensors, nuts.

 

[Starz]

had a few crashes

This could create issues that are not readily visible. The damaged sensor could have internal issues not visible from the outside. Possibly some unwanted material is the motors? Pictures do show some amount of debris. Am I seeing gimbal damage in image 2674?

 

[charliebicks]

I sometimes get the same thing when I first take off and fly over snow. According to the manual, flying over snow or water, or other featureless, terrain can cause the obstacle avoidance sensors to function erratically. I get the same results with the original Mavic three, and the Mavic three Pro. It only happens when the obstacle avoidance sensors are active, which is why you don’t see this when you put it in sport mode. Also, it only happens when I first takeoff. After a minute or so everything works normally. I think the problem is you are flying over water, which is a fairly featureless terrain. On my drones, I set them to stop upon sensing an obstacle instead of trying to fly around it. I bet if you sent your drone in the same mode, yours will act like mine does, and instead of flying left, and right and up and down to avoid imaginary obstacles, it will perform a series of accelerations and stops, all in a straight line until it all settles out. Flying over such featureless, terrain, is driving the obstacle, avoidance sensors, nuts

I think that's a really good point. My drone also heavily displays the erratic flight behaviour at the beggining of a flight - and the behaviour decreases with time. I will try changing the settings to see if it does what your drone does!

 

[charliebicks]

This could create issues that are not readily visible. The damaged sensor could have internal issues not visible from the outside. Possibly some unwanted material is the motors? Pictures do show some amount of debris. Am I seeing gimbal damage in image 2674?

I don't think there is unwanted stuff in the motors. Yes!! the gimbal damage was from a repair I had to do the gimble when I was in the Amazon in Brazil. Perhaps yes, the sensors have had a knock and they malfunction a bit...

 

[charliebicks]

I sometimes get the same thing when I first take off and fly over snow. According to the manual, flying over snow or water, or other featureless, terrain can cause the obstacle avoidance sensors to function erratically. I get the same results with the original Mavic three, and the Mavic three Pro. It only happens when the obstacle avoidance sensors are active, which is why you don’t see this when you put it in sport mode. Also, it only happens when I first takeoff. After a minute or so everything works normally. I think the problem is you are flying over water, which is a fairly featureless terrain. On my drones, I set them to stop upon sensing an obstacle instead of trying to fly around it. I bet if you sent your drone in the same mode, yours will act like mine does, and instead of flying left, and right and up and down to avoid imaginary obstacles, it will perform a series of accelerations and stops, all in a straight line until it all settles out. Flying over such featureless, terrain, is driving the obstacle, avoidance sensors, nuts.

Yup, exactly.

I put the brake mode on, and instead of the drone gaining altitude and fluttering when the sensors´sensed´an obstacle, the drone started and stopped a series of accelaration and decelerations, all at a constant altitude.