Although I find this highly entertaining I do believe it may be a waste of your time labroides. I don't think (s)he is going to learn to read or do anything but make random guesses

phantom-four.co Posted at 2016-6-4 20:12
Although I find this highly entertaining I do believe it may be a waste of your time labroides. I do ...

I think you're right.
No-one is that stupid.
He's just trolling.

leanlinao Posted at 2016-6-4 02:07
You also talked about 400 feet, well the land and highway + obstacles can be that high or higher.

...

Maybe on your planet, but not this one. They maybe that high above sea level but not above the home point. When it lost contact it was higher than the two towers on each side of the highway. I agree that it could be in a tree, but it defiantly did not hit anything manmade at that altitude. I would discount a bird strike because you would see data on the accelerometer data just before loss of contact. Also, you're making assumptions that the OP did not look for his craft. After rereading all of his posts, I cannot find one bit of proof that he didn't. He certainly has never said he didn't, in fact he said that he went to where he thought it should be immediately.

soundbyte58 Posted at 2016-6-4 23:22
Maybe on your planet, but not this one. They maybe that high above sea level but not above the home ...

There are no large birds in that area.

Also if RTH failed, it should have hovered and not moved. Data shows the drone moved and after 4 seconds, it hit something in that highway, it would have been most likely a power line which obstacle avoidance would not detect. 2-3 seconds of movement at that speed is not enough for it to go out of the highway. But ofcourse the connection simply could have cut off and the drone got stuck elsewhere within the route going home. In either situation it indicates a wrong calculation for height which is pilot error.

It's not a drone error at all, the rth enggaged successfuly. The height calculation was at fault. Drone hit something near the highway or drone got stuck with los of signal.
Either way pilot made the wrong calculation.

labroides@yahoo Posted at 2016-6-4 18:33
I think you're right.
No-one is that stupid.
He's just trolling.

You obviously don't believe in magic.
But you also don't know what physics is.
Which makes you a legit troll.
So I'll teach you how to make a top notch guess, finish elementary school then you can take the next step.

leanlinao Posted at 2016-6-4 09:26
There are no large birds in that area.

Also if RTH failed, it should have hovered and not moved.  ...

The only thing that I agree with, is that the craft suddenly lost power, whether by a loose battery or internal fault. The lack of any abnormalities in the Accelerometer data from the IMU, leads me to believe that the loss of power was not related to a collision. If it were, there would be data supporting that. The craft had been holding that altitude for some time before RTH. Unless your theory is that it hit something after it lost power, is it? No one has argued the drone vanished into thin air. And it could hit a any number of objects as it fell, and it could be in a number of places. I just don't see this as justification to vilify or ridicule someone who deserves some empathy.

If not asked was rth recorded before takeoff...I've got a p3p the p4 won't run into anything right?

rustymichaud Posted at 2016-6-4 14:07
If not asked was rth recorded before takeoff...I've got a p3p the p4 won't run into anything right?
...

Yes, the Home Point was correctly updated. Here are some screen shots. the last one actually shows the drone heading home in the last 4 seconds before it went dark.

https://drive.google.com/open?id=0B9PaRJY4GeJQV1RBdm9KZWVmV2s

https://drive.google.com/open?id=0B9PaRJY4GeJQMDF2ZklwXzhrR2s

https://drive.google.com/open?id=0B9PaRJY4GeJQajJvUmFWb3p6Zjg

rustymichaud Posted at 2016-6-4 14:07
If not asked was rth recorded before takeoff...I've got a p3p the p4 won't run into anything right?
...

it's not supposed to, however it can run into objects that are too small for the sensing system. it can also run into things laterally and in reverse.

rustymichaud Posted at 2016-6-4 22:07
If not asked was rth recorded before takeoff...I've got a p3p the p4 won't run into anything right?
...

P4 manual page 22 lists the limitations of the obstacle avoidance system.

.............question;

As it happened to me severely when I flew near heavy metal areas such as boats and confined places and even over a lake which contained iron (I was told, it has) a Compass Error (P3p) what happens if that happens during RTH? Is it possible? Because the P3 went out of control.  This is also terrifying me when I use Litchi App what if...

I also thought P4 would avoid frontal obstacles. !? What does it do, go over it or stop there?

flydodom Posted at 2016-6-4 16:13
.............question;

As it happened to me severely when I flew near heavy metal areas such as bo ...

I don't know if a compass error by itself will interrupt RTH as long as it still has GPS lock. I could be wrong, it hasn't happened to me yet. And you are correct, iron objects or areas where there is a lot of it can play havoc. large concrete structures like parkades and bridges.

leanlinao Posted at 2016-6-4 19:31
It's not magic lol just physics

Too bad for you.

You are an idiot, stop offering ridiculous advice about the subject, of which you have no knowledge.

Why the time gaps in the flight log?  There are entries every .1 second, but right after RTH it jumps from 12:30 to 12:32.9.

jstjohnz Posted at 2016-6-5 08:51
Why the time gaps in the flight log?  There are entries every .1 second, but right after RTH it jump ...

Nice catch..

However it seems like the log entries are not constant through out the logs, you can see that at some parts it's roughly ~0.5s and right before RTH initiation there's also a couple seconds gap.. Maybe the log is only stored when there's activities and position change data and at those times it was either refreshing the location data slower or was standing still.

Not sure

jstjohnz Posted at 2016-6-4 23:51
Why the time gaps in the flight log?  There are entries every .1 second, but right after RTH it jump ...

It doesn't do that on the data I got. 12:30.2 is the only one missing the rest are there.

This is scary to me.  That function has to be a fail safe control.  0% fault tolerance.

Even though I had to use it only once on a P4 when  it was low
in battery and I could not see my iphone screen due to sun glare,
it worked for me.  Upon looking at the details, it seems like a battery
malfunction.

MD_Icarus Posted at 2016-6-5 06:29
This is scary to me.  That function has to be a fail safe control.  0% fault tolerance.

Even though ...

It's bound to miss some anytime there is a gap in radio contact. That being said, I think there is a problem with the log viewer. If you want to see a more complete data set, load the CSV file into a spreadsheet. Then you can see IMU data as well as TX data.

MD_Icarus Posted at 2016-6-5 06:29
This is scary to me.  That function has to be a fail safe control.  0% fault tolerance.

Even though ...

More than likely the battery was loose. I can power up my P4 with the battery not clipped in all the way. I always give it a pull just to make sure it's secure.

Alari Posted at 2016-5-30 13:30
It would help if you had found pieces of it anywhere between the 2 points.
What Dji will ask you to  ...

RTH is  a MUST learn! How will you fly your drone back if you lose signal or a catastrophe happens? Believe me, RTH saved my drone from smashing a hole into someone's roof. The drone was 3000 feet away and I lost signal because it went behind a hill, 5 minutes of no connection, RTH brought the drone safely home. You should at least TRY RTH, switch to ATTI if anything goes wrong?

amelia.bolli01 Posted at 2016-6-5 06:58
RTH is  a MUST learn! How will you fly your drone back if you lose signal or a catastrophe happens ...

Agreed, RTH needs to work if you loose contact. But if a catastrophe happens, it's usually to Late.

A few possible explanations. The drone:
1. Could have hit a bird (yes, it sounds dumb but look it up on YouTube, true fact) and fallen out of the sky while attempting RTH.
2. Faulty Battery\Indicator: If  your battery or voltage/milliamp indicator was broken, it well could be the battery suddenly went bad when the drone was RTH.
3. GoHome not set at the right location: Was your GoHome point correct before, during, and after the flight? If not that is the cause of the crash.
4. Optical Illusions: Sometimes obstacles look lower than they are and drones look higher than they are. Maybe the drone hit a nearly invisible power line?
Look in the area the drone crashed, if it is not near there than look into the possibility of a flyaway.
Hope this helps,
Robi

labroides@yahoo Posted at 2016-5-30 20:52
You really need to look at the  data before you make guesses like that.
There is only a few metres ...

Not true, I have seen some higher that 400 feet

amelia.bolli01 Posted at 2016-6-5 07:09
A few possible explanations. The drone:
1. Could have hit a bird (yes, it sounds dumb but look it up ...

All the bird strikes ive seen on youtube result in the craft being physically jostled. The data does not support that theory. The home point was correct. The battery cells were all good.

amelia.bolli01 Posted at 2016-6-5 07:09
A few possible explanations. The drone:
1. Could have hit a bird (yes, it sounds dumb but look it up ...

There are no powerlines at 422 feet. A thirty story building is only 300 feet. You should look at the logs and read the entire thread. I have look at that area on Google earth from many angles including street photos of the poles. Trust me when I say, no lines and no poles at 422 feet, not there.

Motors fail, props break, batteries die, and signals get lost so be prepared for it. The first thing you should do after you buy a multi-rotor system of any value is get a parachute system, gps tracker, and insurance, not just for the drone but for any damage it might do in case of a crash. It's money well spent if you are serious about flying, especially for you guys the like to fly beyond LOS. Manufacturers really need to consider these must-have-features in the future, especially for quads like these that have no redundancies what so ever and that may be your argument for replacement. ;)

For what it's worth the same thing happened to me after a firmware upgrade, and they did fix it for me in less than a week, but I had all of the above insurances so I was able to recover my unit. For the record DJI did acknowledge at the time that there was a problem with the RTH feature in certain situation that were beyond the pilots control. However I do not know if that has been addressed in firmware updates since then.

Here are the products and services I use:
Mars Parachute Systems:: http://www.marsparachutes.com/
Neary Aerial Media: https://neary-aerial.com/ (UAS insurance)
AMA: http://www.modelaircraft.org/membership/membership/overview.aspx (Liability coverage)
Trackimo: https://buytrackimo.myshopify.co ... cts/trackimo-device (GPS Tracking)

Cloud Chaser On Posted at 2016-6-5 08:36
Motors fail, props break, batteries die, and signals get lost so be prepared for it. The first thing ...

The chute looks interesting, does it have a fail safe in case of powerloss? How is it controlled?

soundbyte58 Posted at 2016-6-6 00:53
The chute looks interesting, does it have a fail safe in case of powerloss? How is it controlled?

Yes, it's called mayday, and comes with the complete bundle. Check out their website for more info. They have videos also on Youtube of it in action.

soundbyte58 Posted at 2016-6-5 22:58
All the bird strikes ive seen on youtube result in the craft being physically jostled. The data do ...

Yes, but what if the INDICATOR was broken?

soundbyte58 Posted at 2016-6-5 23:05
There are no powerlines at 422 feet. A thirty story building is only 300 feet. You should look at t ...

Proof you're wrong: https://en.m.wikipedia.org/wiki/Transmission_tower

Cloud Chaser On Posted at 2016-6-5 10:33
Yes, it's called mayday, and comes with the complete bundle. Check out their website for more info ...

So it how is it activated? By servo? I guess the mayday must have a backup battery, is that how it works? I've whatched the vid but wasn't clear on that point. I'll buy one tomorrow if it has a good fail safe.

amelia.bolli01 Posted at 2016-6-5 11:10
Yes, but what if the INDICATOR was broken?

Are you referring to this flight, or are you making a supposition? If you are referring to this flight I would suggest you load the KML file into google earth and look at it then come back and tell me what you think. You can also load the flight log into a spreadsheet like "numbers" and look at the raw data. I've already provided links to screen shots that show the flight path. It looks completely normal. Usually if the altitude data is messed up, you'll see a lot of vertical lines in the flight path. However, this is not the case here. The only vertical line in his flight was when he took off  and there is smooth telemetry all the way up.

chbrian.cheung@ Posted at 2016-5-29 08:17
The RC was disconnected after RTH was initiated, so the record wasn't sent to the RC. And therefore, ...

After the FW update, did you recalibrate the IMU's and compass?  I find that anytime the FW has been updated these should  be calibrated! You never know if the software corrupted during the FW install.

Rich

RichJ53 Posted at 2016-6-5 11:36
After the FW update, did you recalibrate the IMU's and compass?  I find that anytime the FW has be ...

At take off His IMU was reading
Pitch -1.1 deg.
Roll 0.4 deg.
Heading 136.9 deg

When contact was lost, his IMU was
Pitch -12.6 deg.
Roll -1.1 deg.
Heading 41.9 deg.

The pitch and heading data would be indicative of a craft returning home. With that in mind, I think it's safe to assume the  IMU was happy. And if you zoom in close enough to the very end of the flight path you'll see that the craft had done a u-turn and was moving toward home for 4 seconds.

amelia.bolli01 Posted at 2016-6-6 02:14
Proof you're wrong: https://en.m.wikipedia.org/wiki/Transmission_tower

Sigh...was referring to this part of Hong Kong, not the rest of the world. Of coarse there are high towers somewhere in the world. That was not what this discussion was about. So again i say, there are no high tension power towers or lines where he lost his drone. Only street lamps on the road with underground wiring.

soundbyte58 Posted at 2016-6-5 00:27
I don't know if a compass error by itself will interrupt RTH as long as it still has GPS lock. I c ...

Well, at that moment (i never noticed GPS) but it did not stood on its position and does move all over the place with warning ATI Mode (to switch on). I have another none GPS drone (a racer) it doesn't hover on the spot. So I guess, Compass Error has a negative effect on the GPS mode.  That is why I asked what if this happens during RTH mode, if happened.  

Soundbyte 58 , still no proof it didn't hit a power line?

amelia.bolli01 Posted at 2016-6-6 13:43
Soundbyte 58 , still no proof it didn't hit a power line?

You can quite clearly see in Google Earth that there are no powerlines or towers in the vicinity

amelia.bolli01 Posted at 2016-6-6 00:09
A few possible explanations. The drone:
1. Could have hit a bird (yes, it sounds dumb but look it up ...

"3. GoHome not set at the right location: Was your GoHome point correct before, during, and after the flight? If not that is the cause of the crash."

Rather than offering guesses that aren't relevant, you could look at the actual flight data which shows clearly that the home point was set correctly, there were no optical illusions or powerlines or poles.