Mavic 3 crashes into a big wall with obstacle avoidance on. Video and logs

[Paulark]

Why did this happen?

Link to phantom help log DJI Flight Log Viewer - PhantomHelp.com

 

[brett8883]

Why did this happen?

Link to phantom help log DJI Flight Log Viewer - PhantomHelp.com

Page 22 of the manual.

https://dl.djicdn.com/downloads/DJI_Mavic_3/DJI_Mavic_3_User_Manual_v1.4_en.pdf

The vision sensors do not work on monochrome surfaces including pure white.

They are vision sensors and need variation and texture to see objects. It may have also been too dark in there and the light too flat for the sensors to work properly. It actually did much better then I would have thought. Pretty amazing really.

 

[LoudThunder]

I am not an expert on obstacle avoidance, nor am I privy to DJI's obstacle avoidance firmware's algorithms, but I am a computer programmer and as much as we say that a computer can multi-task, it can't. It can do a lot of things at one time, but in reality, it really just does one thing at a time. It works on one task for a bit, and then it works on the next task, and so forth…

For example, I can make big breakfast: eggs, bacon toast, and orange juice… I turn on the stove, while the pan is heating, I put the bread into the toaster, I put the bacon into the pan, I check the toast, I put the eggs into the pan too. I flip the bacon, but I smell the toast burning, I run to the toaster, but it's too late, I jerk the burnt toast out, and put in fresh bread, then I smell the bacon burning, I run to take the bacon out, but it's really crispy. SO I pour the juice but now I smell the toast again. While taking the burnt toast out, I remember the eggs, but they too are over cooked, hard fried… So, you see, I also multi-tasked breakfast but only the juice gets served…

I would venture a guess that all those variable shapes and structures just overwhelmed the software. Did you notice the stuttering at time 0:42 and again at 0:49. When it crashed into the wall, the Drone was trying to follow you after it lost you as you walked past the wall and its processor running the software to find you and track you probably just took precedence over the obstacle avoidance routine.

 

[Deleted member 84685]

Man that sux alright,,you'd think if artificial intelligence got consumed in something or pre-ocuppied it would just stop instead of goin any furthur,,,yip pretty white wall,,as mention above it had couple of unsure moments ,

 

[maggior]

Page 22 of the manual.

https://dl.djicdn.com/downloads/DJI_Mavic_3/DJI_Mavic_3_User_Manual_v1.4_en.pdf

The vision sensors do not work on monochrome surfaces including pure white.

They are vision sensors and need variation and texture to see objects. It may have also been too dark in there and the light too flat for the sensors to work properly. It actually did much better then I would have thought. Pretty amazing really.

That seems to be the problem to me also. When it got caught behind that wall, the drone was seeing pure white with no shadows at all. It saw a clear path and proceeded forward.

We humans can have this issue as well. When skiing under very flat lighting conditions (a cloudy day), you can lose the ability to see detail in the terrain and find yourself hitting bumps and dips on the slope that you didn't see.

 

[ianwood]

Probably the same reason this t-shirt might confuse an autonomous car.

 

[brett8883]

This was an indoor flight so no rules were broken. I don’t think we need to nanny people so much on what they do, and if you can’t help yourself it would be more effective to be nice about it.

EDIT: Comment I was referencing has been deleted.

 

[zeusfl]

DJI should start making LIDAR sensors more affordable and integrate this into drones like M3 for better detection. For the price of the M3 DJI should be giving us the lasted technology.

 

[johnmont250]

Before I pressed play on the video I guessed he prob walked behind a wall around a corner……..sure enough. The m3 also flies like it’s pulsing and looks awful.

why no hard hats on crew?

 

[Paulark]

Before I pressed play on the video I guessed he prob walked behind a wall around a corner……..sure enough. The m3 also flies like it’s pulsing and looks awful.

why no hard hats on crew?

I thought the same thing, it is pulsing. Is that typical? It acts like it wants to gets lost on the left a couple of times before it actually does. Pretty much makes for unusable footage. Maybe it had something to do with too much white and it’s shifting around looking for something else, who knows… After the tent goes up, no hard hats are required inside.

I’m glad I tested this feature in a small area, moving slowly before I had it track anything moving much faster. It was moving slow enough that it only dinged up a couple of props and sustained no major damage.

 

[BigAl07]

Alright folks... let's remember the basic (and well noted) rule of this forum... BE NICE!!

We can argue and banter but when it becomes personal and rude it's not going to last. I've cleaned the forum and issued the needed "Warnings".

Let's be civil going forward or ignore the thread completely.

 

[brett8883]

the replies were incorrect in stating it was OK and legal to fly over others heads of others since it was indoors - I corrected him

FAA regulations don’t apply indoors.

 

[Mike Mas]

Thanks for the reply - however my remarks had nothing to do with FAA regulations, they have to with proper flying procedures general drone safety. If you hit someone inside a building with the drone and they sue you, they are not going to throw it out of court because you were inside a building and not under FAA guidelines. You're guilty of unsafe flying!

Bottom line - never fly around or over any other person even in your own home. All drones are subject to interference and should never be trusted. The main reason we're losing our flying privileges is because there has been so many accidents. Certainly never trust any type of auto tracking device!

Stay Safe - Mike

 

[brett8883]

Thanks for the reply - however my remarks had nothing to do with FAA regulations, they have to with proper flying procedures general drone safety. If you hit someone inside a building with the drone and they sue you, they are not going to throw it out of court because you were inside a building and not under FAA guidelines. You're guilty of unsafe flying!

Bottom line - never fly around or over any other person even in your own home. All drones are subject to interference and should never be trusted. The main reason we're losing our flying privileges is because there has been so many accidents. Certainly never trust any type of auto tracking device!

Stay Safe - Mike

Anytime you injure another person you have some legal liability. However, there’s no law or regulation that says you cannot fly a drone over people while indoors. There’s not even a law or regulation that even says you have to fly safely indoors. So no it would not be correct to say it’s illegal or a violation or some kind to fly over someone while indoors.

If you had said, “hey, just a heads up it probably isn’t a great idea to be flying that close to people especially with the drone in autonomous mode. You really never know what it might do even when it CAN see the obstacles and getting hit with those props is no fun. They can easily lacerate skin or worse” you probably would have gotten some like buttons and no argument from me.

You know it’s all about the delivery in communication. When you go on and on kicking a guy while he’s down after he probably just damaged a very expensive new toy that just rubs people the wrong way and any chance of imparting actual wisdom gets lost. If we beat up every person that did something questionable on here people are no longer going to come here for advice.

 

[johnmont250]

I thought the same thing, it is pulsing. Is that typical? It acts like it wants to gets lost on the left a couple of times before it actually does. Pretty much makes for unusable footage. Maybe it had something to do with too much white and it’s shifting around looking for something else, who knows… After the tent goes up, no hard hats are required inside.

I’m glad I tested this feature in a small area, moving slowly before I had it track anything moving much faster. It was moving slow enough that it only dinged up a couple of props and sustained no major damage.

Also air currents get really weird inside, it seems like walls suck the drone into them.

 

[BigAl07]

Also air currents get really weird inside, it seems like walls suck the drone into them.

Well said!! Spoken like someone who has been in that situation a few times. It's a lot worse with "manual flight" (aircraft without Positioning control) than with our DJI birds but yes walls seem to suck you in very often LOL.

 

[albertly]

I am a computer programmer and as much as we say that a computer can multi-task, it can't. It can do a lot of things at one time, but in reality, it really just does one thing at a time.

What, what, what??? !!!

Even with one core CPU can make multiply tasks at once by time division for every task (thread) and suspension of others. The time slicing is so short that for all intents and purposes it is multi-tasking.
With multiply cores no need for time division - every core on its own.
A GPU, even better, has many, many cores and ...
In short, go learn computers.

P.S. Your cooking experience and computers, how to say, it's not exactly the same.
However, when you cook, you do many multiply tasks at once - cooking, breathing, looking, thinking, hearing, standing on 2 legs ( quite a task), etc.

 

[AMann]

Lidar would’ve helped, but there’s a less expensive solution. It is too bad DJI did away with ultrasonic sensors on its drones, using those as backup to its optical sensors would really improve object avoidance in low light situations.

 

[LoudThunder]

Well said!! Spoken like someone who has been in that situation a few times. It's a lot worse with "manual flight" (aircraft without Positioning control) than with our DJI birds but yes walls seem to suck you in very often LOL.

The study of "wind Dynamics" is both complicated and beyond my ability to explain it. This not to say I even understand it, but it's just plain weird. When I first started flying small battery powered helicopters indoors, I soon noticed that if I got too close to a wall, the wall seemed to "suck" the copter right into the wall.

As the rotors (propellers) generate lift, they create a downdraft and the downdraft near a wall creates a stream of air or "airflow" that lowers lift on the wall side, causing the craft to dip slightly and that dip moves the craft even closer to the wall until… Well, you know the rest…

As an extreme example of weird wind and the loss of lift when enclosed or even close to a wall. Remember the Bin Laden Raid and what happened to the Blackhawk Helicopter when it tried to land inside Osama bin Laden's compound. As it settled down onto the ground, the rotors completely lost all lift due to the way the downdraft from the rotors became a vortex within the walls. The Blackhawk could not get any lift from its rotors due the vortex effect caused by the walls and the Navy Seals had to destroy the copter with explosives. Unfortunately the Very Classified tail rotor was blown clear and the Chinese Military subsequently bought the technology from the Pakistanis who recovered the wreck.

Bin Laden raid's lone glitch could be headache for U.S. military

Therefore, if you fly a Drone indoors, keeps the prop guards in place or keep the Drone a respectable distance from a wall and unfortunately, Obstacle Avoidance is not there yet, especially when there is little or no contrast. Remember, Obstacle Avoidance is not Radar…

 

[LoudThunder]

What, what, what??? !!!

Even with one core CPU can make multiply tasks at once by time division for every task (thread) and suspension of others. The time slicing is so short that for all intents and purposes it is multi-tasking.
With multiply cores no need for time division - every core on its own.
A GPU, even better, has many, many cores and ...
In short, go learn computers.

P.S. Your cooking experience and computers, how to say, it's not exactly the same.
However, when you cook, you do many multiply tasks at once - cooking, breathing, looking, thinking, hearing, standing on 2 legs ( quite a task), etc.

Oh, you are exactly right about the Body's Automatic Functions, like breathing, heart beating, food digesting, standing, etc… and the body takes pretty good care of this without any interference on our part.

And in the case of a computer (the one core CPU), it also has its own "Body's Automatic Functions" like performing its priority subroutines like: updating the GPS, directing the power to each motor, receiving operator inputs (even when flying autonomously), interpreting inputs from its sensors (even when it sees nothing, it has to make that determination), and so much more.

The programming team for DJI assigns the Order of Presidency to each subroutine and whether it was the Drone was not paying "attention" to obstacle avoidance at the time of the crash or the OA was fooled by the lack of Contrast due to the white walls, we can only guess.

Of course, as I mentioned in another response on this topic, the Drone might have just got too close to the wall and got "sucked" in with no escape…