At NAB, 3D Robotics showed off several new features but one of them seems completely essential now I realize it would have prevented a crash last weekend. I had accidentally flown my DJI P2V+ behind a large pile of rocks. When it lost connection, the drone decided to fly home through the rocks. A 3D Robotics drone uses a different algorithm. It retraces its steps (they call it rewind). That means that if you lost the control signal by flying behind an object, such as a tall building, the drone will go back along its own path until you can regain control. This seems almost trivial to implement. The drone just needs to record its GPS route and be able to go back along its own path.

I got lucky with the crash. The drone was exactly where it was supposed to be and the only "damage" was that the camera gimbal arm would not turn. It was easy to fix by just loosening the set screw on the arm, moving it away from the housing and tightening it again. Thankfully I had one of those camera protection brackets installed which saved the gimbal from any real damage. Still the crash would not have happened if the drone had retraced its steps. I asked at the DJI booth and the Phantom 3 will not have this feature but they appreciated the suggestion. If everyone asks for this feature (at least as an option) perhaps we can convince DJI to add it in an update. Let's not wait for the Pantom 4.

hopefully they took out the feature where your Phantom flies off and you never see it again

cayers13@gmail. Posted at 2015-4-17 04:14
hopefully they took out the feature where your Phantom flies off and you never see it again

I have not experienced that feature yet. Let's hope I never do.

Why did the Phantom not rise up to the preprogrammed height RTH that you set it at?

Was the pile that high?

The problem with the drone "thinking for you" is that you'd really have to brainstorm EVERY possible scenario....which is almost impossible. What would happen if it flew behind the pile of rocks and then lost GPS because of some steep canyon walls (in a quarry, for example)?

That's just one situation - but my thinking is that many of the failsafes actually cause problems....maybe more than they fix. It may be best to have 3 or 4 "modes" which you are forced to choose one of before flight. For example, over water it might say "never land if anything else is possible - on RTH there is no need to rise up past 10 meters" , etc.

I think we (active forum and drone users) are still pioneers. It's likely that future models will not only log their use, but allow us to send these back constantly (user selection) to the maker so they can have the real data as to what the best failsafes are.

We tend to think this "decision tree" is easy...but I suspect it is not.

Man...this lack of features and lack of concern to implement is really driving me crazy.  There is market share to be lost here and the way 3dr is aggressively attempting to compete (in some cases outdoing), DJI should probably get on the ball.  These are the people who want to put money in  your pocket, but you're forcing our hand elsewhere.  You are the status quo of commerically manufactured uav's so you set the standard, not look at it pass by and say we dont care to catch up we'll let them go.

droneflyers.com Posted at 2015-4-17 04:40
Why did the Phantom not rise up to the preprogrammed height RTH that you set it at?

Was the pile th ...

The Phantom had 100 feet programmed in to rise to in the case of RTH. That is 100 above the start location though. I think that the top of the rock pile must have been more than 100 feet above the start point. I have since set it to 400 feet.

The path retrace feature is just as simple as going straight back to the home point but I think it is more likely to be safe than going along directly to the home point considering that an object that causes the signal to be lost will also cause the drone to crash if it attempts to fly through it and most of the time I am standing close to the home point.

ok but what if your battery dies on its messed up path home? then you will be complaining about that.:@

lauxchet@yahoo. Posted at 2015-4-17 06:08
ok but what if your battery dies on its messed up path home? then you will be complaining about that ...

That's the first thing I thought too.

lauxchet@yahoo. Posted at 2015-4-17 06:08
ok but what if your battery dies on its messed up path home? then you will be complaining about that ...

Think about it a minute: You don't need it to go all the way home. You just need to get it back under control. The quickest way to do that is to fly it back along its path. It probably only needs to reverse course  a short distance to get it back in control and then you can fly it wherever you need to. If it gets low on battery it should always fly straight home.

how about this know where your flying and set rth acordinly. Not trying to argue just saying

lauxchet@yahoo. Posted at 2015-4-17 07:08
how about this know where your flying and set rth acordinly. Not trying to argue just saying

I really really thought I did. I was flying in front of a long row of rocks. I had not realized there was a second row behind the first so when my white dot of a drone passed behind the large pile of rocks it came as a complete surprise to both pilot and spotter. For the record, this is my very first crash with a Phantom 2 drone. I try to be extremely careful all the time. The point is that even if you are being careful, it can be hard to judge relative distances beyond a couple of hundred meters.

The point is that even if you are being careful, it can be hard to judge relative distances beyond a couple of hundred meters.
very true.

Again, there are so many variables - that these features often confuse as much as help (IMHO).

Saying 3DR - with a non-existent drone - is implementing lots of useable features - seems like hot air. Colin definitely is a salesman, but based on the claims vs. delivered on the Iris and then the Iris+ my faith is waning. Let's check back in 6 months and see what's delivered and how it works after thousands put them to the test.

There are so many "ifs" involved. Also, there is philosophy. DJI could throw in vast amounts of features. I suspect, since Apple is their model, they are trying to appeal to "the rest of us" who actually want to use a product...that is, make it simple. So far they seem to be 100% correct in this assumption. The chances of 3DR selling 1/10th as many units is very low, IMHO.

But even to get to that volume of sales, 3DR will have to deliver products that actually work as well or better than they claim. They are spending so much time and energy pumping it up that people expect the Second Coming. Yet we've almost never seen a complex quad that got things right the first time.

Back to this situation - it's my opinion that the current crop of drones are best used LOS and within a range of a couple hundred meters. It will take a lot of redesign - as well as changing of our codes and laws - to have inexpensive machines which are safe and reliable to totally autonomous flight out of easy LOS.

I guess  the odds of crashes and loses increase with distance.....and all of this may be like the ground station. I think DJI removed it due to liability and reliability. They have to be careful not to be seen as encouraging use of these in ways which the authorities (FAA, etc.) do not approve of.  Also, they will have people yelling at them and calling for warranty, etc - but less so if the pilot is using 3rd party applications. I suppose you'll have to "sign off responsibility" on a lot of these 3rd party apps as well as some DJI features.

Some of this reminds me of the "Windows and Android have so many more features" debates which have went on forever. I'm not doubting that a small subset want these abilities, just saying that the market has proven most people would rather have "simple".

grangerfx@gmail Posted at 2015-4-17 07:58
I really really thought I did. I was flying in front of a long row of rocks. I had not realized th ...

On the P3, the video link should help.

I do like the idea of rewind feature.

I second that feature of rewind.
The benefits outgo any cons I can think of by far.

DJI or 3DR? Phantom 3 or SOLO? Either way you go you won't have a perfect and fail proof drone. Both will have their pros and cons and it will be up to you to make the decision. It will be a while before we have a drone that has all the features we want and is fail safe and even longer before it becomes relatively affordable.