Mini 4 Pro Unstable on the pitch axis

[Droning on and on...]

My advice is to hold off on sending it back at this point, keep flying and have fun and just live with it for the time being. I doubtvsending it back will result in a fix yet, given the nature of the problem, and how many people are seeing it.

This is very likely a PID issue, and we'll see a firmware fix. Not surprising we're seeing some new oscillation issues as the suckers get so light with these powerful motors. As the drone get lighter and lighter, the damping effect of mass gets less effective.

 

[BudWalker]

Some may want to follow this over on the DJI forum. DJI is claiming this is normal behavior.
Mini 4 pro oscillating

 

[Droning on and on...]

@BudWalker, no chittering!! You've got to be kidding

 

[slup]

Isn't this just according to the usual procedure...

1:st line of defence:
"Thank you for reaching out and we're sorry for the inconvenience. We'll forward this to our relevant team"

2:nd line of defence:
...this is normal

Then...
Silence...

Suddenly... a new & exiting changelog:
"Bug fixes and enhancements"

 

[TinajaEco]

Thank you @BudWalker for the log analysis and thank you @slup for your explanation. Because sending drones back from my region is painful I would like to make sure that this is not a firmware / design issue, and not just my unit. There are at least 4 of us here that are experiencing the same issue. If we attract enough attention on the official forum maybe DJI engineers will take a look at these logs and tell us if it is fixable by a firmware update, or we actually ended up with faulty units. I previously crated this thread on the official DJI forum, but still did not get any response from DJI: Mini 4 pro oscillating

Any luck with DJI on this? I’ll call them when I’m back home from field work.

 

[tuxtard]

Any luck with DJI on this? I’ll call them when I’m back home from field work.

Not really. Today they've informed me that they cannot analyze my logs because I am using "third party software".

 

[TinajaEco]

had a late start in the field due to some logistical issues and called DJI:

After a 45min call and answering myriad diagnostic questions, they have “escalated” my case. When they email me back I’m supposed to attach a video of the issue and send it to them. The CS person I was talking to would not admit to knowing anything about this issue, but he did say “oh, so it’s flying violently” in a way that made it seem like he’s dealt with it before…

I’ll have my work partner shoot a phone vid later today and will post it if anyone is interested. It’s always windy in this zone, so recreating the issue should not be a problem.

 

[tuxtard]

had a late start in the field due to some logistical issues and called DJI:

After a 45min call and answering myriad diagnostic questions, they have “escalated” my case. When they email me back I’m supposed to attach a video of the issue and send it to them. The CS person I was talking to would not admit to knowing anything about this issue, but he did say “oh, so it’s flying violently” in a way that made it seem like he’s dealt with it before…

I’ll have my work partner shoot a phone vid later today and will post it if anyone is interested. It’s always windy in this zone, so recreating the issue should not be a problem.

If you can, please upload your logs to official DJI forum thread. Maybe they will accept yours if they won't mine.

 

[TinajaEco]

If you can, please upload your logs to official DJI forum thread. Maybe they will accept yours if they won't mine.

If someone can give me idiot proof instructions on how to do this via IOS I will.

 

[tuxtard]

If someone can give me idiot proof instructions on how to do this via IOS I will.

I don't use iOS, but maybe this will help:

 

[TinajaEco]

Active Track Videos - TinajaEco

This video hosted by SmugMug; your photos and videos look better here.

garymcdaniel.smugmug.com

Quick and dirty video.

Directly into a 12mph breeze, measured with my Kestrel meter that is USFWS approved for my biological monitoring work.

Also, it looks like I can’t upload my flight log until I’m out of the field and back to a proper computer. But I think I downloaded the log file to my phone and would be happy to share it with someone that has access to a proper computer to post….

 

[tuxtard]

Active Track Videos - TinajaEco

This video hosted by SmugMug; your photos and videos look better here.

garymcdaniel.smugmug.com

Quick and dirty video.

Directly into a 12mph breeze, measured with my Kestrel meter that is USFWS approved for my biological monitoring work.

Also, it looks like I can’t upload my flight log until I’m out of the field and back to a proper computer. But I think I downloaded the log file to my phone and would be happy to share it with someone that has access to a proper computer to post….

Thanks for the video. That's exactly what I'm experiencing.

 

[tuxtard]

After posting the following to the official DJI forum about this issue my user level just got downgraded. So, be careful what you post over there.

 

[Droning on and on...]

Active Track Videos - TinajaEco

This video hosted by SmugMug; your photos and videos look better here.

garymcdaniel.smugmug.com

Quick and dirty video.

Directly into a 12mph breeze, measured with my Kestrel meter that is USFWS approved for my biological monitoring work.

Also, it looks like I can’t upload my flight log until I’m out of the field and back to a proper computer. But I think I downloaded the log file to my phone and would be happy to share it with someone that has access to a proper computer to post….

Wow, that it REALLY bad. Obviously "wrong". Gotta see if I can make mine do that...

That sure looks like a D increase adjustment to the PID, maybe with a bit less P.

 

[tuxtard]

Wow, that it REALLY bad. Obviously "wrong". Gotta see if I can make mine do that...

That sure looks like a D increase adjustment to the PID, maybe with a bit less P.

I can always recreate it just by flying straight into the wind with constant forward input in normal mode with OA set to bypass. You can try the same.

Now when I think about it, I wonder if everyone else who experienced this issue is using OA in the bypass mode?

 

[mobilehomer]

After posting the following to the official DJI forum about this issue my user level just got downgraded. So, be careful what you post over there.

View attachment 174132View attachment 174131

Nothing to do with your post at all. I had the same thing, then found this - Update: DJI Forum Level and Posting Threshold Adjustments

 

[TinajaEco]

Now when I think about it, I wonder if everyone else who experienced this issue is using OA in the bypass mode?

So this only happens in bypass mode for you?

 

[tuxtard]

So this only happens in bypass mode for you?

Yes, but I kept it in the bypass mode for a long time. I will have to test other modes as well to be sure. Drone flies differently in bypass and brake mode. In bypass mode it performs more aggressive moves and angle changes, so in brake mode it might handle the headwind differently.

 

[BudWalker]

Just discovered that my Mini 4 does this but corrects itself before it gets to be a problem.

The top plot shows the same 2.5 Hz oscillations starting at 186.7 secs but then stopping at 189 secs. Also seen in the bottom plot is the horizontal speed decreasing some and the vertical speed oscillating. The pink background indicates Bypass mode.


Those interested can obtain the .txt log here:

DJIFlightRecord_2024-03-29_[10-31-06].txt

drive.google.com

 

[slup]

Just discovered that my Mini 4 does this but corrects itself before it gets to be a problem.

The top plot shows the same 2.5 Hz oscillations starting at 186.7 secs but then stopping at 189 secs. Also seen in the bottom plot is the horizontal speed decreasing some and the vertical speed oscillating. The pink background indicates Bypass mode.
View attachment 174156

Those interested can obtain the .txt log here:

DJIFlightRecord_2024-03-29_[10-31-06].txt

drive.google.com

Is this also seen when flying sideways (only aileron), or backwards? And is this tied to the OD mode bypass only... if so it's something else than a tune issue.

...That sure looks like a D increase adjustment to the PID, maybe with a bit less P.

Those really slow oscillations usually comes from a high I... which is dampened by rising P, which in turn can require a higher D.