JJBspark Posted at 12-19 06:17
Thanks for the P4P pro update, only now we need is a definition of strong GPS....
11 sats will not bring the craft in OPTI / ATTI, so imo Tripod mode will work OK and will not show this effect on the OP drone. (and 11 sats at the very end of this flight, the weird behaviour started earlier with more than 15 sats)

Only use tripod where gps is strong.....

P mode works best when gps is strong.

You can see a clear distinction between both these statements.

Long exposures , taking photos with exposure of 1/8 seconds, using tripod will much improve these photos.

hallmark007 Posted at 12-19 06:37
Only use tripod where gps is strong.....

P mode works best when gps is strong.

Different writer / translator i guess...
And not in the MP2 text so another writer, so imo no difference in all position modes, they all need good and stable GPS.

So believe what you believe, i do the same  

cheers
JJB

JJBspark Posted at 12-19 07:02
Different writer / translator i guess...
And not in the MP2 text so another writer, so imo no difference in all position modes, they all need good and stable GPS.

Again you seem to read into everything that suits your way of thinking, both those statements are clearly different, and I will always advise that using tripod mode users need to have strong gps to use it optimally, and having used it myself quite often I realise that strong gps will insure a better working in tripod, I’m certain that this is the correct way to use tripod mode and is on par with what the manual says.
The M2 manual clearly cautions you against using tripod mode at weak gps, and to insure craft is within line of sight, I’m sure there is a very good reason for this.
slan leat agus go raibh maith agat

Thank you, guys both for the such acitve discussion.
I beleive we need to pay a little bit more attention to the vision position system.

Let me provide some more detail about this accident.

First, as I already mentioned, I could find my drone in the woods. It took about 30 minutes at the area 10x10 meters (bushes and trees and high grass).
Second, it looks like that during those 15 seconds of uncontrolled flight nobody was hurt. I condsider myself as the luckiest person at that day.
Third, the drone looks okay (only propellers have moderate cracks). The testing on the next day still provides no issues. I condsider myself as the luckiest person at that day again.
Fourth, I would be happy to discover that that was MY ERROR. I prefer to know that the M2P is reliable aircraft and, if properly used, it provides no reason to worry.

Now let me tell you what I remeber from the accident.
Shortly:
The AC was hovering above the middle of the river with a pretty strong current. It was about 5-6 meters above the water.
Than the AC started moving by itself and in 4 seconds reach the bank of the river and went to the woods. Consider it was at the same 5-6 meters above the ground in the forest with many trees (pine trees with the height up to 40-50 meters), bushes and so on.
The AC continued its uncontrolled fly for another 10 seconds sometimes accelerating up to 60-70 km/h, made a kind of u-turn at the end and fall down on the very soft combination of tree branches, bushes, plants and grass.

So, my inclination is to beleive that the AC vision system was confused by running water below. The AC automatically swithed form the Tripod mode to ATI mode (where it cannot hold the position and the speed increases). I couldn't keep it (I have a very limited experience controlling the AC in ATI mode, if none at all) on position an let it go to the woods.

Unfortunatly, after the AC reaching the wood and presumably obtaining the correct readings of the surface below, its Vision Position System couldn't reset the ATI to the normal (inspite of the fact, that we can see the correct numbers in the log - VPS Altitude at 16.18.6 - as soon as the AC was above the ground).

What do you think?

hallmark007 Posted at 12-19 07:16
Again you seem to read into everything that suits your way of thinking, both those statements are clearly different, and I will always advise that using tripod mode users need to have strong gps to use it optimally, and having used it myself quite often I realise that strong gps will insure a better working in tripod, I’m certain that this is the correct way to use tripod mode and is on par with what the manual says.
The M2 manual clearly cautions you against using tripod mode at weak gps, and to insure craft is within line of sight, I’m sure there is a very good reason for this.
slan leat agus go raibh maith agat

He, the old hallmark is back online.

Cannot make good point and than accusing me of read everything in the way its suits me.
Not really trhe case, i read and overthink it technically, based on knowledge, own tests, logic and common sense.

I agree with you that Tripod is better for video`ing, drone reacts less fiercely on user input.
Just read the MP2 manual and i cannot find any Caution about using the TriPod mode / GPS, can you give me the page # please?
If i missed that i am pleased to give you the credits for that.

BTW In the tech spec DJI doesn`t make any difference between hover accurancy in relation to position modes.

Guess your last Irish sentence was a really friendly one.

cheers
JJB

SK Posted at 12-19 08:17
Thank you, guys both for the such acitve discussion.
I beleive we need to pay a little bit more attention to the vision position system.

Hi SK,

I don`t think so.

When flying low above that river (VPS height active (3.0 meter)) but VPS postioning not active, so it was using GPS positioning and not Vision positioning.
In ATTI with no RC input the drone will have flat pitch and roll angles. (was not the case).ATTI mode is not written in the flightrecord, cannot think of a reason why it should not have been wrtitten.
Don`t think that in ATTI your drone could made that last turning move. *
* when i look at the angles of your drone and google earth, think it hit some top of the trees wich made the drone to 'turn'.


cheers
JJB

JJBspark Posted at 12-19 08:20
He, the old hallmark is back online.

Cannot make good point and than accusing me of read everything in the way its suits me.

I’m getting bored with you now, and your personal comments. I will leave below where it clearly says in English caution when using tripod mode with weak gps, I will also leave another warning from a P4 Pro user.
I have noticed that no matter what I commented on this thread you were in behind me trying to rubbish what I said.
I’m not sure why you keep doing this, and again above you try to rubbish what I said about caution while using tripod mode.
But maybe you will read the manual instead of just looking through it.
Your remarks about the old hallmark I find childish coming from someone who has told users recently that is was perfectly ok to take off without gps lock.
Maybe you now might retract what you said above having read what is actually in the manual.
You seem to be very dogged in everything you say but not willing to learn.

hallmark007 Posted at 12-19 08:43
I’m getting bored with you now, and your personal comments. I will leave below where it clearly says in English caution when using tripod mode with weak gps, I will also leave another warning from a P4 Pro user.
I have noticed that no matter what I commented on this thread you were in behind me trying to rubbish what I said.
I’m not sure why you keep doing this, and again above you try to rubbish what I said about caution while using tripod mode.

Thanks for the page, but that is general info using the vision, not a Caution in relation to TriPod mode.
Sorry but your text "M2 manual clearly cautions ...." is not true in the M2 manual special for the TriPod mode.

So if you get bored with me, thats your feeling cannot help you with that.

Rubbish i don`t use, just read some of your comments and do ask if you help others with that.
Well that`s for other forum users to make their own opinion.

If you see my checklist you know that i do not take off with a GPS lock.
But if you want to do that (to obtain more GPS sats) feel free to do so, but hover in place (don`t fly away) and be prepared for ATTI.  So if you "use" my words use the whole context please.


I will leave you alone Hallmark, had a short moment the feeling that you have changed.

cheers
JJB

JJBspark Posted at 12-19 09:13
Thanks for the page, but that is general info using the vision, not a Caution in relation to TriPod mode.
Sorry but your text "M2 manual clearly cautions ...." is not true in the M2 manual special for the TriPod mode.

I think anyone who presents a checklist fro a drone advising new or old users it’s ok to take off without gps lock is frankly talking through their hat.
I just wouldn’t want to be anywhere near any so called pilot who thinks this is safe and correct.
It seems you haven’t changed much yourself, just because you say it doesn’t make it right.
I bid you good day.

I hear you. I took my Mavic 2 Pro out for its maiden flight today. Took it nice a easy running through simple scenarios. All good until I decided to use activ track following my daughter on a scooter. Drone went crazy started spinning and before I could do anything slewed sideways into a tree. Heart in mouth raced over only to see it fall to the ground. Thankfully it landed upside down on the sand underneath. My question is what the hell happend? What happened to obstacle avoidance? I have been flying for two years and this is my first crash. Not happy

I looked at the street level Earth view and the trees were thick with under growth.  In looking at the actions of the drone in the "woods" it truly appears it was a PIN BALL in an arcade.

The "speed" may be associated with rapid change in directions and that effect on the IMU positioning.   To be honest I didn't see any pine trees in street view ( not to say they weren't there)  but the under brush was so thick...I don't know how the little bird got as far as it did.

jjBSpark,  can you tell what the actual wind was doing from the logs?   There was another post of a guy in TriPod Mode flying from a tall hilltop......was trying to get back to HP....but the bird continued backward at 5 to 7mph even with the right stick full forward ( he forgot he was in TP Mode ) it auto landed 1500 ft below....and last I heard he could not find it.

Randy

rwynant V1 Posted at 12-19 10:36
I looked at the street level Earth view and the trees were thick with under growth.  In looking at the actions of the drone in the "woods" it truly appears it was a PIN BALL in an arcade.

The "speed" may be associated with rapid change in directions and that effect on the IMU positioning.   To be honest I didn't see any pine trees in street view ( not to say they weren't there)  but the under brush was so thick...I don't know how the little bird got as far as it did.

Hm. Indeed. I just looked the street view and must confess that, even if there were pine trees, they were somewhere inside the park. Okay. Whatever trees were there, the pure bird was flying inside and detected only some obstacles above. Why it didn't detect (and didn't stop) them in front of it? Or left and right?
Why it flew at all, while for almost 15 seconds the sticks of RC were in neutral position?

Just after the accident, I rushed to the open place and after short examination replaced the battery and made a few short, low, slow test flights. In tripod mode. Everything worked as expected: the bird hovered on the place; moved slow and stable according the RC commands; it stopped by itself after sensing the obstacle.

SK Posted at 12-19 08:17
Thank you, guys both for the such acitve discussion.
I beleive we need to pay a little bit more attention to the vision position system.

Usually flying over water is ok, fast moving water can play havoc with sensors coupled with the fact that you were in tripod mode. You may well be correct that vision sensors were affected by the moving water, you also point to needing strong gps , I believe this is also the case.
Thinking about the wind, in tripod mode aircraft should be able to withstand 18mph, but I don’t see if you mention anywhere how strong the wind was .

hallmark007 Posted at 12-19 11:55
Usually flying over water is ok, fast moving water can play havoc with sensors coupled with the fact that you were in tripod mode. You may well be correct that vision sensors were affected by the moving water, you also point to needing strong gps , I believe this is also the case.
Thinking about the wind, in tripod mode aircraft should be able to withstand 18mph, but I don’t see if you mention anywhere how strong the wind was .

Okay. The number of satellites was quite good - up to 19 and dropped only when the AC was on the ground in bushes. Does it mean that the AC had enough GPS?
Wind. This is a very tricky question. First, that day I saw some indicators of wind before coming to the location (HP). Being of the HP even very close to the water, I didn't feel any wind.
I also don't remember any single warning about the wind. Whereas, the previous days I had a lot. But not that day.
I also reviewed all the recordings and couldn't see any indicators of wind.
On the other hand, I know that above the middle of the river current might be a very strong wind.
However, the last position above the water current wasn't the first at that day. Other times (in that  flight) the position had a little bit more meters above the water. But the AC had been above the water at that day many times and there was no single warning about the wind.

Hi all,

For all forum readers who thinks post #49 is little sick, like wtf is this for a weird posting....

Here is my checklist, easy to understand, isn`t it?


cheers
JJB

rwynant V1 Posted at 12-19 10:36
I looked at the street level Earth view and the trees were thick with under growth.  In looking at the actions of the drone in the "woods" it truly appears it was a PIN BALL in an arcade.

The "speed" may be associated with rapid change in directions and that effect on the IMU positioning.   To be honest I didn't see any pine trees in street view ( not to say they weren't there)  but the under brush was so thick...I don't know how the little bird got as far as it did.

Hi rwynant,

Happend to a operator in India, blowing backwards for long distance.
About you wind question, need to calculate that, but 1/3 the last drifing away part MP wityh no user input pitch down 23 degrees down with left bank 10 degrees, moving backwards with 18 m/s. Busy with algorithem to automate that as well.
DJI speed indication is derived also from drone fly angles, most of the time accurate but in case of IMU and/or Compass errors i see a diiference between DJI speed and calculate speed using LatLon to LatLon versus time. In this flight only at the end there is a difference, calculated speed is about max 20m/s during steady part of that last flown distance.

If the latLon postions (see the line GE) is what the drone actually flown that means that the GPS positions were recorderd OK, Thus with no user input in TriPod mode MP wants to keep its position.
Thats`s why nose down and little left. (wind blowing from approx. 010 degrees)
The only reason i know when flying in a position mode facing too much headwind is moving backwards with nose down attitude.
But if there is another cause than i am happy to accept ofcourse. But not a single error in this flight (apart at the end into the trees)

As said before: in the flightlog Vision Postion is not active so its flying in a GPS position mode.

If i may say so ; my advise is always to fly with a screen recorder active, any more information could be very usefull in mishaps like this.

cheers
JJB

JJBspark Posted at 12-19 13:17
Hi all,

For all forum readers who thinks post #49 is little sick, like wtf is this for a weird posting....

I think you will find two versions of this checklist posted on this forum.

alifeofimages Posted at 12-19 09:44
I hear you. I took my Mavic 2 Pro out for its maiden flight today. Took it nice a easy running through simple scenarios. All good until I decided to use activ track following my daughter on a scooter. Drone went crazy started spinning and before I could do anything slewed sideways into a tree. Heart in mouth raced over only to see it fall to the ground. Thankfully it landed upside down on the sand underneath. My question is what the hell happend? What happened to obstacle avoidance? I have been flying for two years and this is my first crash. Not happy

You may want to start a new thread as your post might get lost in the chatter!

Thanks for sharing.