Hello all -

Writing on behalf of my dad, who I gifted a Mavic Mini in January. Looking for some answers and hopefully a replacement from DJI.

Per his logs he has taken over 50 successful flights in a variety of conditions, including several in the exact same location of the incident. He knows the machine quite well and this flight was under normal conditions.

Here's what he reports:

• He set the home point.
• He flew the drone straight up to a safe height above the trees (about 38m).
• It hovered for a few moments. No wind.
• The drone suddenly charged westward with zero control input.
• It dove into the trees a short distance later.
  

A few days later, we did manage to located the downed drone very close to where the flight data indicates. It's significantly damaged.

The viewer shows a series of messages / errors as the drone flies away and crashes.

• Homepoint set.
• Ascent to 38m.
• Max power load reached.
• Sensor error.
• And post crash, GPS / Motor error.
  

Logs are attached. Appreciate any insights from the community.

Thanks,
HB

https://www.phantomhelp.com/LogViewer/JNCMGGK8EY5CE64Z0VTQ

Looks like compass error to me but you should wait for others with more experience reading logs. If the data in the log regarding attitude is correct, it was tilting to the right and flying left, which doesn't match. Could be compass interference, did the drone take of from nearby a metal object? Is the heading of the drone shown in the log above correct (facing away from the street) or was it actually facing towards the street?

That flight has all the tell-tale signs of a Yaw Error situation, caused by launching from close to a magnetic field that's caused the IMU Yaw to initialise incorrectly.
The most common cause is launching from reinforced concrete surfaces, but it can be from above a bolt in a wooden deck etc.

Ice_2k Posted at 3-22 15:14
https://www.phantomhelp.com/LogViewer/JNCMGGK8EY5CE64Z0VTQ

Looks like compass error to me but you should wait for others with more experience reading logs. If the data in the log regarding attitude is correct, it was tilting to the right and flying left, which doesn't match. Could be compass interference, did the drone take of from nearby a metal object? Is the heading of the drone shown in the log above correct (facing away from the street) or was it actually facing towards the street?

Thanks Ice. It took off from a composite deck built on a timber frame. Nails and screws, but no metal beams.

Not sure about the heading info but I'd assume its correct.

Labroides Posted at 3-22 15:34
That flight has all the tell-tale signs of a Yaw Error situation, caused by launching from close to a magnetic field that's caused the IMU Yaw to initialise incorrectly.
The most common cause is launching from reinforced concrete surfaces, but it can be from above a bolt in a wooden deck etc.

Thanks Labroides.

This was launched from a composite deck with wood supports. No metal beams, just nails and screws. Checked underneath myself.

Is this something DJI would typically cover?

HB

According to historical data provided by https://www.ventusky.com/ the wind at altitude (100m or 328 feet) was 24 mph, that is near the maximum wind holding capabilities of the Mavic Mini at 13 m/s (about 29 mph).

The wind gusts were of about 36 mph or 16.1 m/s.

Your dad's Mavic Mini has been clearly carried away by the wind, reaching 45 miles per hour despite trying desperately to counter the tendency to be blown away, until it was CAPSIZED mid air and went tumbling down as IMU, compass and inconsistent GPS data at the end clearly show (as it was tumbling down).

I am afraid your dad's MM loss is the direct result of his flying choices. I do not see any compass error for the data I have.

Should have been more careful and prepared. As for the MM I am quite confident it could have been saved, piloting it back at a lower altitude in sport mode since the battery was full.

Addendum after 5 minutes: nope... thinking about it, it could have been an incredibly difficult task to save it, because the remote control point was deeply encircled by trees. That is a very poor launching point. LOVE YOUR DOWNVOTEs guys ;)

HeliBoi Posted at 3-22 16:12
Thanks Labroides.

This was launched from a composite deck with wood supports. No metal beams, just nails and screws. Checked underneath myself.

Nails or screws will do it .

m80116 Posted at 3-22 16:18
According to historical data provided by https://www.ventusky.com/ the wind at altitude (100m or 328 feet) was 24 mph, that is near the maximum wind holding capabilities of the Mavic Mini at 13 m/s (about 29 mph).

The wind gusts were of about 36 mph or 16.1 m/s.

Per my viewing of ventusky, the wind conditions at the flight time on the day in question was quite mild, consistent with the account. Also no high wind warning anywhere on the log.

https://www.ventusky.com/?p=39.85;-75.55;6&l=wind-100m&t=20200311/1800

I notice you seem not to believe what you're being told. Having a critical spirit it is a good thing,
I think it's not up to me to make you believe what I've read for you.

Ask yourself, why the MM was that considerably tilted towards the homepoint up until the moment it was capsized by the wind ? Was it because it was trying to legitimately stay put in the position it was coming from or was it just a random tilt for all that time ?

Why didn't the compass headings and yaw values changed after the AC left the launch point ? Was it just a stuck compass that instantly went OK (or bad who knows) in the middle of a grove, or was it just becasue there was ZERO interference at the launch point, and the Mini responded perfectly as the uneventful climb suggests ?

Why did it reach almost 50 mph while its speed limit (which is notorious for being hard to reach) is just 29 mph. Was it because of nitrous oxide in the motors, or was it because of wind ?

Ask yourself these questions and try to give them logical answers. One is free to believe anything... perhaps heavy metals in the blood stream could affect the Mavic Mini compass orientation, who knows...

m80116 Posted at 3-22 17:16
I notice you seem not to believe what you're being told. Having a critical spirit it is a good thing,
I think it's not up to me to make you believe what I've read for you.

I don't know the answer to those other questions, but it does certainly appear you're wrong about the wind. And considering the source you cited lists wind speeds / gusts at 100m as around 3mph, it seems pretty damn possible that something did go unexpectedly haywire.

No?

"Having a critical spirit it is a good thing."

- M80116

You're absolutely right... I see something around 4 to 6 mph! (I was stuck at 1 AM, where I found the conditions I reported). Told you being critic is a good thing.

My fault for not adjusting the bar... I even watched the time and didn't adjust. Anyway... this doesn't change my conclusion though.

Rather it should prove how reported or predicted weather conditions can really be misleading, being temporally so close yet so different. I've flown in perfectly calm winds while the forecast was indicating storms and I've had to renounce flights despite reported wind forecast well within the limits (and for gusts!) the wind was perceivably strong and received Strong Wind Warning within a couple of minutes.

I am truly sorry for your loss HeliBoi.

m80116 Posted at 3-22 17:37
You're absolutely right... I see something around 4 to 6 mph!  (I was stuck at 1 AM, where I found the conditions I reported). Told you being critic is a good thing.

My fault for not adjusting the bar... I even watched the time and didn't adjust. Anyway... this doesn't change my conclusion though.

Cheers M. I did like your night flight video btw.

Hi HeliBoi,

Had a look at your short flight too.

Reaching a height of 36 meters, MM started to drift away in the heading 240-250, Craft heading North.

If a compass yaw error is the cause of this than the input is a incorrect direction to hold MM in a hover. Data in the log shows that the roll right and little forward picth is the right correction. I doubt that this "move-away line" is a TBE alike curve, wich is 'normal' for a compass yaw drives move away.

Roll right angle up to its maximum, so after a while "NotEnoughPower" is logged. Meaning blades are running at max speed to try to correct its movement.

So  IMO probably not at yaw/compass error, i would say wind. But read that wind is checked and cannot be the cause of this move-away.
BUT the first error in the log is :  "Compass calibration required"......so indeed compass related?? if craft was at another heading than in the log at takeoff, than the corrective action in the wrong direction....
Hope that DJI can help you out, as DJI did many times now for loosing MM`s.

cheers
JJB

According to the attached logs ... especially the DAT log this is easily diagnosed to a plain & simple Yaw-magYaw disagreement coming from powering on the Mini in a magnetic disturbed environment. Winds hadn't anything to do with the FlyAway as such but they were the starting factor ... more about this further below.

First the wind speeds from Airdata.com, which correlates well with those recorded in the DAT log ... these winds were WELL within the Mini spec.



Then to what actually happened ... straight out from the logs.

From Power on 2 flights were actually conducted, 36sec after power on (probably indoors or roof sheltered as the navHealth is zero) a first flight were conducted with a proper AutoTakeoff & Forcelanding, during this first flight the VPS sensors reports only a ascend to 4,67m and the down & lasts for only 22sec. Already here the Yaw error were in place that will cause the FlyAway during the second flight.

After this first flight the Mini is probably carried outside to a place with a more unobstructed view of the sky ... this as the navHealth climbs to 4 with (only) 6 satellites locked. At 57sec the second AutoTakeoff starts, throttle is applied for ascend ... and at 80sec now at 32m height the light wind start to push the Mini slightly & the flight controller (FC) need to correct the position ... and the FlyAway starts, reaching a maximum heading speed of 29,4m/s at 88sec. in a slightly down going trajectory ending with hitting the tree tops about the same time as max speed is reached.



So out from the chart below I will try to explain the cause of the (pilot)-error & all other events during these 2 flights ...

The colored fields & graphs:

Dark blue field followed by a light blue field = Auto Takeoff
Pink field = Force Landing
Red graph = Barometric height
Light blue graph = Ultra sonic (VPS) sensor height
Black graph = RC Throttle input (Ascend/Descend)
Green graph = #satellites locked
Blue graph = navHealth (from 0 worst to 5 best)
Purple graph = IMU Yaw angle
Yellow graph = mag Yaw angle (compass angle)
Magenta graph = Heading speed

The way a DJI drone sets it's knowledge about the heading angle for the coming flight is to lock the IMUYaw angle (Purple) to the magYaw angle (compass)(Yellow) at power on. As seen in the most left side in the chart those 2 agrees fine immediate after power on ... BUT IN THIS EVENT the compass is off due to magnetic disturbance! This is seen approx 10sec later were the compass (Yellow) & IMUYaw starts to disagee as the Mini is moved out from the magnetic disturbance & the compass starts to show a correct angle. At auto takeoff the IMU & the compass is disagreeing by 158 degrees ... meaning that the FC in the Mini now have the wrong information in what direction it points.

The auto take off takes place and throttle inputs (Black) is applied for ascending ... everything is fine until the Mini reach 32m height & starts to be affected by the southern mild winds ... the Mini starts to deviate from the position hold to the north in reality ... but as the heading info is almost a half turn wrong for the Mini it think's it's drifting towards south. The FC applies thrust to correct the position (to the wrong direction) but sees it get an even larger position error ... & redo the previous action ... leading again to an even larger position error. And then it spins out of control & the FC goes nuts. All of this happens in lightning speed in the FC & the Mini reaches both speeds & tilt/roll angles outside the spec. If this can continue without the Mini hitting something it will eventually go into ATTI mode as the FC gives up ... but usually drones already have crashed by then.

NEVER ever power up your drone in a magnetic disturbed area ... preferably never carry it elsewhere fore a take off ... ALWAYS check the the drone icon on the map in the app, check so it points equal to relating objects in the map as it's pointing in reality ... if not, ALWAYS power down, move to another take off spot well away from the previous, power on & check again, icon direction in app map equal to reality, then it's safe to take off.

Sorry, but this was a pilot error ... you will be at the mercy of DJI, they don't have to honor any warranties for this if they don't want to.

(Click on the graph to make it larger...)

slup Posted at 3-23 01:36
According to the attached logs ... especially the DAT log this is easily diagnosed to a plain & simple Yaw-magYaw disagreement coming from powering on the Mini in a magnetic disturbed environment. Winds hadn't anything to do with the FlyAway as such but they were the starting factor ... more about this further below.

First the wind speeds from Airdata.com, which correlates well with those recorded in the DAT log ... these winds were WELL within the Mini spec.

Hi slup,

Disagree of the 2 after 10 secs ?? Do you mean 10 seconds aftter powering up, so in the chart 10 from the start of the chart ?I see in your chart that they start to disagree even more at 35 secconds?
At minus approx 20 they start to have the same curve but in disagree.

Can you explain more?

cheers
JJB

HeliBoi Posted at 3-22 17:50
Cheers M. I did like your night flight video btw.

For me it’s very typical of a compass yaw issue, unfortunately they are pretty common and carry almost the same trends.

That news is bad but of late I have seen dji offer warranty for this type of loss, so do start up a case and hopefully your dad will get back flying soon .

hallmark007 Posted at 3-23 02:59
For me it’s very typical of a compass yaw issue, unfortunately they are pretty common and carry almost the same trends.

That news is bad but of late I have seen dji offer warranty for this type of loss, so do start up a case and hopefully your dad will get back flying soon .

Yep, that`s why checking compass before takeoff is so important!! if only all people know and do this check.....

cheers
JJB

JJB* Posted at 3-23 03:10
Yep, that`s why checking compass before takeoff is so important!! if only all people know and do this check.....

cheers

It’s a bit of a mystery why dji refuse to put this as an instruction in the manual, unless they feel it’s not 100%, but I’ve been using it for many years and it’s pretty foolproof .

hallmark007 Posted at 3-23 03:26
It’s a bit of a mystery why dji refuse to put this as an instruction in the manual, unless they feel it’s not 100%, but I’ve been using it for many years and it’s pretty foolproof .

Even if it is a good check for 97%....just do it  ;-)  

DJI should listen more to experienced users and take their advice. Think they sell so many drones worldwide that staying quiet is their policy. (see how quiet it is about their latest drone : MM....)

JJB* Posted at 3-23 02:03
Hi slup,

Disagree of the 2 after 10 secs ?? Do you mean 10 seconds aftter powering up, so in the chart 10 from the start of the chart ?I see in your chart that they start to disagree even more at 35 secconds?

Do you mean 10 seconds after powering up ...

Yes ...

As I wrote ...
"As seen in the most left side in the chart those 2 agrees fine immediate after power on ... BUT IN THIS EVENT the compass is off due to magnetic disturbance! This is seen approx 10sec later were the compass ..."

The amount of disagreement or how equal that is over time have less to do with it ... DJI FC's usually seems to handle disagreements below 30-35 degrees, but then ...

m80116 Posted at 3-22 16:18
According to historical data provided by https://www.ventusky.com/ the wind at altitude (100m or 328 feet) was 24 mph, that is near the maximum wind holding capabilities of the Mavic Mini at 13 m/s (about 29 mph).

The wind gusts were of about 36 mph or 16.1 m/s.

Your dad's Mavic Mini has been clearly carried away by the wind,  reaching 45 miles per hour despite trying desperately to counter the  tendency to be blown away, until it was CAPSIZED mid air and went  tumbling down as IMU, compass and inconsistent GPS data at the end  clearly show (as it was tumbling down).
Your misinformation is becoming even worse.
You don't know the first thing about reading flight data or what can go wrong with these things, yet you prognosticate like you are an expert.
Anyone taking advice from you is making a big mistake.

m80116 Posted at 3-22 17:16
I notice you seem not to believe what you're being told. Having a critical spirit it is a good thing,
I think it's not up to me to make you believe what I've read for you.

Why did it reach almost 50 mph while its speed limit (which is notorious for being hard to reach) is just 29 mph. Was it because of nitrous oxide in the motors, or was it because of wind ?
If you actually knew anything about drones, you'd understand what a Yaw Error does.
Despite being completely ignorant you are spreading your misinformation still.

No-one is going to be flying in a wind that could blow a drone away at 50 mph.
It would be difficult enough just standing up in that wind.
What a turkey!!

To be honest I don't know what most of you seem to be raging about.

My claims are easily verifiable by anyone using the simple flight reader online.  While I see printouts and many other data that match up with the flight log, FRAP, i.e. the only free offline data analysis resource I have access to is not completely congruent with such data.

- With FRAP using the .txt log (the only one I can read) there's no indication of compass interference.
- The online data viewer should display much of what FRAP sees but timecodes are in disagreement, but that is recurring problem.
- What I see that FRAP doesn't show, and I don't get if there's some timing problem in FRAPs or actually some other data is displayed is that MM is tilted between 15 and 20° of roll pretty much the entire carry-away flight length (unti it tumbles down).

Everybody can check on https://www.phantomhelp.com/LogViewer/JNCMGGK8EY5CE64Z0VTQ/ and verify (even with a simple Protractor against the screen, unless is in reverse) that the bubble indicator shows that MM was actively countering a wind because at that point the GPS signal was good and strong, and was tilted between 15° to 20° TOWARDS the homepoint. That's not what happens when you have GPS position mismatch or COMPASS/YAW disagreements, where the AC actively fly in a different direction... he was fighting HARD to keep the position it was coming from!

What I see on the printouts I can't have access to is something that could very well be perfectly normal, as I don't even see a point of delta variation between the YAW/Compass data, at last not that that spatial resolution.

Now, about the hit a tree theory: well... I don't know, it seems a bit unrealistic to me. I think we agree at that point the drone started tumbling down. For what I've seen from Google Street View pictures trees in the area seem to be around 15 to 20 meters or 65 feet tall, which should suggest it was capsized by the wind, which was already so powerful to carry it away despite MM countering it with 20° tilt towards the homepoint.

Unfortuntely as I have no way to read IMU data directly I can't see if the instant tumbling of the MM is compatibile with a hit or a gust of wind.

Thanks Labroides for showing us again with your arrogance, rude manners and your unintuitive way of exposing things how not to perorarate a cause, you've surely won the TURKEY on that, actually being detrimental to the concepts you're trying to stand by.

m80116 Posted at 3-23 05:37
To be honest I don't know what most of you seem to be raging about.

My claims are easily verifiable by anyone using the simple flight reader online.  While I see printouts and many other data that match up with the flight log, FRAP, i.e. the only free offline data analysis resource I have access to is not completely congruent with such data.

and was tilted between 15° to 20° TOWARDS the homepoint.

That "TOWARDS" quickly turns into "AWAY FROM" if the compass data was incorrect and the drone was actually facing the other way around.

The available data (compass/IMU mismatch, wind speeds from that location at that time, the huge speed quickly reached by drone, the fact that it starts so suddenly instead of gradually being pushed back by the wind) simply doesn't support the wind scenario. It does however match pretty good with a drone interference issue.

m80116 Posted at 3-23 05:37
To be honest I don't know what most of you seem to be raging about.

My claims are easily verifiable by anyone using the simple flight reader online.  While I see printouts and many other data that match up with the flight log, FRAP, i.e. the only free offline data analysis resource I have access to is not completely congruent with such data.

I am by no means an experienced student of these logs, but the bubble indicator looks flat and stable as it passes 100ft. I'm happy to provide a photograph, but the trees in question are not skyscraper height, topping out around 50-70 feet max.

I guess it could have been a freak white squall at that altitude, but this doesn't seem super likely.

HB

slup Posted at 3-23 01:36
According to the attached logs ... especially the DAT log this is easily diagnosed to a plain & simple Yaw-magYaw disagreement coming from powering on the Mini in a magnetic disturbed environment. Winds hadn't anything to do with the FlyAway as such but they were the starting factor ... more about this further below.

First the wind speeds from Airdata.com, which correlates well with those recorded in the DAT log ... these winds were WELL within the Mini spec.

Thanks for this thoughtful analysis.

Seems generally wild to me that this would be a "magnetically disturbed area." It's a wooden deck. And I can share previous logs that show multiple flights originating from this exact spot. And considering the catastrophic nature of this type of error, it's amazing there wouldn't be more robust protections in place for a $500+ piece of machinery.

We'll see what DJI can do.

m80116 Posted at 3-23 05:37
To be honest I don't know what most of you seem to be raging about.

My claims are easily verifiable by anyone using the simple flight reader online.  While I see printouts and many other data that match up with the flight log, FRAP, i.e. the only free offline data analysis resource I have access to is not completely congruent with such data.

If I was you I’d quit while I was behind, this is only going to get worse for you.

I think you should try to understand what’s going on before committing to answers that won’t help anyone, you crashed your own drone failed to put up logs and whined that it was djis fault, since then you have shown an arrogance towards others simply because of their experience.
I can tell you if you bothered to learn from those with experience you wouldn’t be spewing out this rubbish on a daily basis and further confusing users who are actually looking for help .

Ice_2k Posted at 3-23 05:57
and was tilted between 15° to 20° TOWARDS the homepoint.

That "TOWARDS" quickly turns into "AWAY FROM" if the compass data was incorrect and the drone was actually facing the other way around.

Interesting because I've thought about some other eventualities but I am not in a position where I can verify them right now...

I have FRAPS indicating about 2° of ROLL mid-flight which is not congruent with the Phantom Viewer ONLINE data log.

I have the bubble level which seems to be the AC angle roll rather than a TRUE bubble level, where it stays flat with the horizon (you roll right, the right  fluid dives into the horizontal line), I've tried to verify to no avail.

I thought that angles didn't have anything to do with compass but were always relative to AC, like calculated from accelerometers or gyros, which are always set in a certain way, much like the accelerometer is present and can detect angle in Smartphones where the compass is missing, like older Samsung J7 for example.
If some of you know for sure why you don't just tell us instead of playing the highly erudite emeritus Professors.

I don't know... I think we all need more explaining. So... with the help of a push it reached in excess of 50 mph... so the wind certainly had a role.

HeliBoi Posted at 3-23 06:25
Thanks for this thoughtful analysis.

Seems generally wild to me that this would be a "magnetically disturbed area." It's a wooden deck. And I can share previous logs that show multiple flights originating from this exact spot. And considering the catastrophic nature of this type of error, it's amazing there wouldn't be more robust protections in place for a $500+ piece of machinery.

"...Seems generally wild to me that this would be a "magnetically disturbed area."

First ... the logs doesn't lie, this isn't a theory or a speculation, it's pure facts from the DAT log.

The drone wasn't powered on were it took off the second time ... and what was inside those walls & perhaps under that wooden deck? Imagine that you know that concrete constructions like walls & floors are all reinforced with steel bars ...

And for the wooden deck ... it takes no more then a screw or a nail to disturb the compass, if this happens during power up you will face this error. One really good strategy is to power on the drone in your hand then after that all is powered on properly, place it straight down for take off ... by doing this you keep the compass at least well above the ground (as most disturbance usually comes from there). This will not save you though, if walls around you is the reason for the magnetic disturbance.

This happens for drones way more expensive then the Mini also ... with one unique exception.

The DJI M2 series is today the only drone that on it's own can correct these kind of errors ... if it's not moved after the power on. The M2 corrects the IMUYaw to the magYaw (compass) when this kind of error occurs ... & with this stops these kind of FlyAway's from happening.

m80116 Posted at 3-23 06:38
Interesting because I've thought about some other eventualities but I am not in a position where I can verify them right now...

I have FRAPS indicating about 2° of ROLL mid-flight which is not congruent with the Phantom Viewer ONLINE data log.

Match the distance to the speed you’ll find it doesn’t, which shows you up once again for making up stuff and how little you really know.

hallmark007 Posted at 3-23 06:37
If I was you I’d quit while I was behind, this is only going to get worse for you.

I think you should try to understand what’s going on before committing to answers that won’t help anyone, you crashed your own drone failed to put up logs and whined that it was djis fault, since then you have shown an arrogance towards others simply because of their experience.

STOP offending and spreading false information. Not only I published my logs, my videos, my pictures but I also managed to prove you wrong in that thread. I didn't crash anything and I am having the same RC problems CONTINUALLY with my second drone.

This is a what a MISERABLE individual is... spreading FALSE information about another person about things that are completely IRRELEVANT to the FACTS in question. I already reported you in the past (as several others do like me, with off topics and trolling).

You're free to go on with your campaign of constant denigration, that's only going to belittle yourself even more. GO ahead... go on... brag about it. I gloat about people like you that can't move one once they've ben publicly shamed.

That's why I tend to quote what you write... because I can take the blame if I was wrong for not acknowledging a problem I couldn't detect with no .dat file access and data that don't match up (FRAP is indicating 2° of roll while the online Phantom Log Viwer about 20)... I am ready to accept I was mistakenly lead to believe something WRONG.

But you WON'T. You will never accept anything... despite having proven you wrong in my MM incident thread, despite you never lose one occasion to swoop down on me for everything, against all common sense... because apparently, I've hit your pride and boy that hurt.

m80116 Posted at 3-23 06:38
Interesting because I've thought about some other eventualities but I am not in a position where I can verify them right now...

I have FRAPS indicating about 2° of ROLL mid-flight which is not congruent with the Phantom Viewer ONLINE data log.

... so the wind certainly had a role.

The winds were exceptional mild in this flight & had nothing what so ever to do with this ... my advice is that you start to learn reading flight logs ... not only the TXT but also the DAT ... if a theory can't find support in the logs it didn't happen.

... It's that simple.

m80116 Posted at 3-23 06:57
STOP offending and spreading false information. Not only I published my logs, my videos, my pictures but I also managed to prove you wrong in that thread. I didn't crash anything and I am having the same RC problems CONTINUALLY with my second drone.

This is a what a MISERABLE individual is... spreading FALSE information about another person about things that are completely IRRELEVANT to the FACTS in question. I already reported you in the past (as several others do like me, with off topics and trolling).

  3#
“I can PM my flight data... no public posting. I am a bit concerned not to appear on the news “


Your words Turkey.

slup Posted at 3-23 06:58
... so the wind certainly had a role.

The winds were exceptional mild in this flight & had nothing what so ever to do with this ... my advice is that you start to learn reading flight logs ... not only the TXT but also the DAT ... if a theory can't find support in the logs it didn't happen.

While I agree with you... there's only one "little" problem. While I've tried to HELP, providing as much information as I could I simply couldn't see what you saw in the .dat file. I think it could be pretty reasonable to agree that from where I stand I provided a pretty plausible explanation.

I am sorry if I was mistakenly lead to believe otherwise... I am ready to accept and learn... but WHAT do I have to learn ?

I even went ahead and asked privately in this forum if I could detect mismatches in compass YAW headings with FRAP and the answer was pretty much you could.

While I'd like to be able to read .dat files...

I have NEVER found a single person willing to explain how to read simple csv data, how to read data on FRAPS, save the fact that at the moment I don't know of any free program to access .dat log files.

So... since the tools available to me are unreliable as I've seen with the roll data or time not being reported equally between FRAP and Phantom Log viewer, I will abstain from now on to formulate hypothesis since I lack the programs and necessary confidence with the ones I have available to me.

I humbly ask forgiveness to our fellow MM friend HeliBoi if I wasn't up to the task.

m80116 Posted at 3-23 06:38
Interesting because I've thought about some other eventualities but I am not in a position where I can verify them right now...

I have FRAPS indicating about 2° of ROLL mid-flight which is not congruent with the Phantom Viewer ONLINE data log.

I thought that angles didn't have anything to do with compass but were always relative to AC, like calculated from accelerometers or gyros, which are always set in a certain way, much like the accelerometer is present and can detect angle in Smartphones where the compass is missing, like older Samsung J7 for example.

Indeed, tilt angles don't have anything to do with the compass. The IMU just tells you the drone is tilting to the right, in the drone's coordinate system. You need to add the compass and gps information to that in order to transform "tilting to the right" into "tilting towards the home point". And if the compass information is wrong, tilting AWAY FROM the hp could actually be seen as tilting TOWARDS the hp.

TBH I thought it was like Smartphones that tell top from bottom even without compass or GPS data.

But anyways... since even JJB went down with me saying "So  IMO probably not at yaw/compass error, i would say wind" I'd like to know once and for all if it wasn't something that you could really spot from FRAP or the Phantom Log viewer. I guess no, NO WAY... the only data to corroborate the Compass/YAW error for me is now a little screenshot with lines I have no experience with.

I am not saying I don't believe what I've been told... but I'd like to verify by myself. Because right now I am thinking with 20° roll it reached 45 mph, which is about 20.1 m/s, that's a whopping 8 m/s over the design limit with just a 20° roll... is this correct? So it must have been a pretty breezy wind.

Tell me now this forum isn't full of spiteful babies... you publish some humble question to better understand and you get instantly downvoted. Are we all born learnt ?

No man, you probably got downvoted (just guessing here as i don't use the up/down vote thingy) because you came really strong asserting what happened and being ironic about it (e.g. the nitrous oxide remark). You certainly didn't get downvoted for "asking a humble question", your attitude at the start of this thread was anything but humble. Just my 2 cents, maybe I'm way off but that's how I read your replies, take it as you will.

Also, i'm gonna be honest with you, you lost me at "my main argument (the wind speeds at time of flight) was wrong because i read the time wrong but i won't let that change my mind" Not very critical thinking if you accept only evidence that points to the solution you were already thinking of and ignoring said evidence when it contradicts you.

m80116 Posted at 3-23 07:31
TBH I thought it was like Smartphones that tell top from bottom even without compass or GPS data.

But anyways... since even JJB went down with me saying "So  IMO probably not at yaw/compass error, i would say wind" I'd like to know once and for all if it wasn't something that you could really spot from FRAP or the Phantom Log viewer. I guess no, NO WAY... the only data to corroborate the Compass/YAW error for me is now a little screenshot with lines I have no experience with.

Not want to break into you great discussion but read my post again, read after BUT!

If drone actual heading was not equal as the indicated heading in the log, than this is a typical exapmple of a yaw/compass 'fly-away'.

And yes, at first sight with only txt data is doesn`t look that way.


FRAP uses only txt data, so this kind of yaw/compass disagree cannot be seen in FRAP. Sometimes it shows a rapid compass change, also an indication of a yaw/compass disagreement with the same consequences.

PS1speed indication in the flightrecord.txt does not always shows the correct value with yaw/compass/imu errors, often to much.see this where the red line is the calculated GPS speed. (max 21.2 m/s)

PS2
Put your drone in front of you on a table facing away from you ; this is North,
Now rotate clockwise 150 degrees on you,  (disagree of yaw and compass values)
Move craft little to the left on your table (you are the wind)
Now apply roll right....(SW thinks it is actual north facing) to get back to its position....
Understand what happens (look at the GE map too)

PS3check option in FRAP to show the time uses in PH, so than looking at the same time = same roll angles

So always check your craft heading in the app before take-off !!

cheersJJB

Ice_2k
Also, i'm gonna be honest with you, you lost me at "my main argument (the wind speeds at time of flight) was wrong because i read the time wrong but i won't let that change my mind"  Not very critical thinking if you accept only evidence that points to the solution you were already thinking of and ignoring said evidence when it contradicts you.

Just to make my reasoning clear. Would you have changed your mind if all the data you could access pointed to one direction and you instantly notice a variable that is wind, being of a such high uncertainty, changed? At 1 AM it was so powerful it would have easily overpowered a Mini, so with my moderate experience I've found perfectly calm days where the forecast was showing rages and the opposite (calm wind and actual conditions very windy) I decided I couldn't revert my decision on that. Sometimes I've even found that nailing it down on time is pretty hard. Therefore I did assume the wind must have been still pretty powerful.


You provide me with new evidence, I am ready to change my mind. I have no such shroud of untouchable wisdom as some thundering here would like to have.


What is for sure is that even if I was mistaken in this occasion I rapidly acknoledged that, asked forgiviness, tried to better understand and be brought up to par and explained that I was led to believe otherwise aided by the tools that I use (which can't contemplate some functions), apparently not alone in this regard.

What's different between me and people like Labroides or hallmark007 is a SEA of ATTITUDE and honesty... their RUDE, OFFENSIVE, SCORNING words will REMAIN once again as a testament of their moral statures, to belittle them even more to eyes of any future forum visitor.

Thanks @JJB for the explanation on FRAP... you can't definitely tell any cue of wrong compass interference from that, at least I couldn't.

m80116 Posted at 3-23 05:37
To be honest I don't know what most of you seem to be raging about.

My claims are easily verifiable by anyone using the simple flight reader online.  While I see printouts and many other data that match up with the flight log, FRAP, i.e. the only free offline data analysis resource I have access to is not completely congruent with such data.

Thanks Labroides for showing us again with your arrogance, rude manners and your unintuitive way of exposing things how not to perorarate a cause, you've surely won the TURKEY on that, actually being detrimental to the concepts you're trying to stand by.
Keep spouting complete nonsense about things way beyond your experience and that you cannot understand, and you can expect to see more of what you perceive as arrogance and bad manners.
You have a lot to learn before you can give useful drone advice.

What's different between me and people like Labroides ...
The difference is that I've safely flown DJI drones many thousands of kilometres over six years and learned a lot from my experience.
I don't guess and only comment when I know something for a fact.
The same cannot be said for you.