ColdForged Posted at 2018-3-5 08:06
There it is, the judgement police have finally arrived!

I'm learning, dude. I've never had one of these before. I don't know what the count is supposed to be.

You'll get a lot of that one here, unfortunately. Trust me... I know all too well.

I honestly don't have an answer for you, I'm just very happy to hear you got yours back.

Wachtberger Posted at 2018-3-5 10:28
You have my highest appreciation for this response, thank you indeed! All of us had to go through this learning process when we started and asking questions here is the right thing to do. I am most grateful to all those who have answered my questions and continue to do so.

You and Bekaru Tree... my bastions of hope on this site. I was genuinely worried about posting my new question due to the amount of garbage from my last post. I still haven't even read any replies. Some people on here are nasty, rude, full of themselves, and they really have no reason to be. Aren't we all supposed to be here under a common interest? Instead, it seems like too many people have something to prove.

So thank you to you, Bekaru Tree, and all the other helpful, kind people on here.

ColdForged, an interesting discussion you've generated on this thread. You were right to post, because it's a good way to learn and us too from such experiences (I've never experienced a fly-away, for example, and I own a few DJI drones and have been flying for a while, so it's interesting to read about).

In this instance, I'd propose you keep it simple and remember just one rule: don't send the little guy on its way until you receive the "Home Point has been updated" message. It won't set that unless it's connected to enough satellites in the first place, and that's where it'll RTH (so long as it maintains enough satellite connections) until the Home Point is set again.

Enjoy your new drone, and read the forum. There's a lot of experience here.

Edit: and make sure everything is appropriately calibrated, as Aardvark has proposed, noting that it'll ask you to calibrate IMU and compass if required.

Please try to fly the drone in another open area, calibrate the compass before taking off, also, refer to the answers above, fly the drone when satellites stabled. If the issue persists, you can try to export via DJI Assistant 2 and upload your flight data to Dropbox and sync your flight record of this flight and PM me with your DJI email account, we can try to check the data.

Punchbuggy Posted at 2018-3-5 17:49
ColdForged, an interesting discussion you've generated on this thread. You were right to post, because it's a good way to learn and us too from such experiences (I've never experienced a fly-away, for example, and I own a few DJI drones and have been flying for a while, so it's interesting to read about).

In this instance, I'd propose you keep it simple and remember just one rule: don't send the little guy on its way until you receive the "Home Point has been updated" message. It won't set that unless it's connected to enough satellites in the first place, and that's where it'll RTH (so long as it maintains enough satellite connections) until the Home Point is set again.

" just one rule: don't send the little guy on its way until you receive the "Home Point has been updated" message. "

Also note that it says to please check the home point to see that it is correct.  Look at the screen, zoom up on it, and see if the H is in the correct location.

Wachtberger Posted at 2018-3-5 12:30
I first had that impression as well when I had just received my MA. It took longer than my Spark to link to sufficient satellites. But in a number of reports (not related to MA) I have also read that after a major change in location (in my case delivery from China to Europe) this is normal. In the recent flights my MA linked up quite quickly but I shall keep on monitoring.

I have had this same experience with most GPS devices that I have owned (excluding phones). I believe this is because the device will save the last location used and will use this information to speed up the process. If you move the device too much while it's off, then this location does not help. Somewhere in the process of finding the location, the GPS will have narrowed down the location to a few places that are nowhere near each other.

The reason this doesn't happen with phones is that they use wifi and cellular to get the starting location.

GazFromBrum Posted at 2018-3-5 13:22
There is lots of talk on this thread of number of sats required...... I'm not sure anyone remembers that these things will fly without GPS holding your hand. The initial story tells how the Mavic started to drift and a climb was initiated to avoid trees....  there is even the comment "no input on right stick"..... there's no mention of trying to fly back or control the aircraft...... no mention of lack of control.

The Mavic Air as all DJI drones don't require GPS at all to fly or to return to take off position..... they just require a pilot that's prepared to fly their drone.

This is a valid point. I admit, when I was in the middle of this -- a drone that, to my mind, just went haywire -- my biggest concern was trying to make sure it wouldn't crash into trees. If you look at the track, it flew straight over trees and was pretty quickly lost to my LOS. I could hear it but couldn't tell precisely orientation or direction.

You bring up a question, though. I was afraid to attempt to control the right stick because I didn't want to exacerbate the problem. I pressed RTH and prayed it would show up... which luckily, this time it did. What would have happened if I attempted to control it via the right stick? In my mind, if it's going upwards of 20 MPH in a random direction, if I press opposite stick, would it simply counteract that other direction and be stationary? Or would it then begin moving in the direction I have indicated with the stick? I base my knowledge of how it flies based on my experience: a stable, stationary platform based on its knowledge of its position then moving according to my input. I assume it felt it was stationary since it had no inputs even while it was veering around in that crazy loop... so would my inputs have been relative to that motion?

Again, first drone, first experience with this. Regardless, I have many things to add to my pre-flight checklist!

I sent you  PM might help give you a better understanding of how satellites lock on.

Would have been interesting if you had hit the pause button to see what happened.  I know its difficult to react quickly when the quad is maneuvering in a manner you are not expecting, but in my mind the pause button could be the best option in this situation (at least in the way I understand it should work).  I hear RTH mentioned a lot more than the pause button, and sometimes I think this can compound the problem.  To me at least, RTH is my last option.

Hack Posted at 2018-3-6 05:58
Would have been interesting if you had hit the pause button to see what happened.  I know its difficult to react quickly when the quad is maneuvering in a manner you are not expecting, but in my mind the pause button could be the best option in this situation (at least in the way I understand it should work).  I hear RTH mentioned a lot more than the pause button, and sometimes I think this can compound the problem.  To me at least, RTH is my last option.

I hold my finger over the pause button when I'm doing quick shots. Hitting the pause button during a situation where the drone is flying erratically because it doesn't have good GPS or compass isn't going to help unless you thought hitting the home point would help first and were cancelling that. Pause only stops the drone if the drone knows what stopped is. It wouldn't hurt to hit the pause button though like hitting the home button would when the AC doesn't really know where home is.

ColdForged Posted at 2018-3-6 05:33
This is a valid point. I admit, when I was in the middle of this -- a drone that, to my mind, just went haywire -- my biggest concern was trying to make sure it wouldn't crash into trees. If you look at the track, it flew straight over trees and was pretty quickly lost to my LOS. I could hear it but couldn't tell precisely orientation or direction.

You bring up a question, though. I was afraid to attempt to control the right stick because I didn't want to exacerbate the problem. I pressed RTH and prayed it would show up... which luckily, this time it did. What would have happened if I attempted to control it via the right stick? In my mind, if it's going upwards of 20 MPH in a random direction, if I press opposite stick, would it simply counteract that other direction and be stationary? Or would it then begin moving in the direction I have indicated with the stick? I base my knowledge of how it flies based on my experience: a stable, stationary platform based on its knowledge of its position then moving according to my input. I assume it felt it was stationary since it had no inputs even while it was veering around in that crazy loop... so would my inputs have been relative to that motion?

Coldforged...... don't be thinking I was having a pop at you because I wasn't, I was more surprised at the amount of people with more flying experience that were saying don't take off without 11 or 12 sats. Practising controlling the aircraft without GPS assistance is far better advice than wait for GPS...... GPS can be lost after take off in which case RTH or Pause will do nothing to assist you.

Enjoy your MA and don't let these little scares put you off..... they are all part of the flying excitement but certainly practice some manual control too.

"Pause only stops the drone if the drone knows what stopped is"

Well that's interesting.  I can understand losing the home point, but with all of the intelligence built into these machines, I'm a little surprised if it did not know it was moving.  You may be totally right, I'll have to do a little playing around to see if I can emulate this.  Interesting fodder to consider...

Hack Posted at 2018-3-6 05:58
Would have been interesting if you had hit the pause button to see what happened.  I know its difficult to react quickly when the quad is maneuvering in a manner you are not expecting, but in my mind the pause button could be the best option in this situation (at least in the way I understand it should work).  I hear RTH mentioned a lot more than the pause button, and sometimes I think this can compound the problem.  To me at least, RTH is my last option.

Pause will only work if you have gps, pressing in Atti mode will do nothing, as we suspect OP may have had weak gps in that case pause may have worked.

This is an interesting thread to read - I must say that. Nonetheless there are a few things which are a bit off - or at least they seemed to, the way the posters have written. Let me explain a bit to get the point across.

First thing - to get a horizontal position you need at least 3 satellites. So x and y and time. To get altitude you need 4 satellites - so x and y and z and time. However this does depend on the position of the satellites around you and them being spread around the horizon is the best option (so for 4 satellites every 90 degrees, for 3 satellites every 120 degrees etc). However - the elevation is mostly badly done. One of the reasons for this is the fact that GPS uses WGS-84 as the ellipsoid to represent the world as it is but the world is geoid, so no even patterns there. In horizontal positioning this isn't much but in elevation this is a problem.

Second thing - quite a few people here mentioned "a satellite link" or "satellite connection". Just to clear this up - there is no connection. The satellites transmit their data and the whole ephemeris data of the system. That is why - in the old days - you needed around 45 minutes to one hour (or even more if unlucky) to get a position on a cold device. It needed to receive all the ephemeris data before it could calculate your position. To clarify - your position is calculated by your device based on ephemeris data received by the system. The transmission of the satellites doesn't change from one satellite to another. There is not link back from your device - it doesn't have enough power to do so. You only receive and based on your reception your position is then calculated.

Just my 3 cents to clarify a few points... ;-)

Cheers!

I read somewhere that flicking it into sports mode is a good way to regain control again. If doing this just be more gentle with the sticks.

Intresting tread,
but as newbe, I have a considering, GPS are a way to give you coördinates, what have coördinates to do with not working pause button pressing?

Just for reference... I idle for about 5-10 minutes before lift... I wait for max sat connects while I am doing pre-flight checks in the DJI GO 4 app. If you are doing pre-flight checks then you would already have the 12+ sats links before lift anyways... so try to get in the habit?

Others may do things differently... this is what I do.
I re-seat the battery and inspect for swelling or any damage.. I verify the battery is seated with a click. (this eliminates any doubt/builds confidence of the power source.)
I check.. props props props... I run my fingers down the props and also inspect for stress and cracks, check compass, IMU, battery temp, AC temp, battery levels, signal levels and strength, RTH settings, verify sensors are all in working order, no errors and unlocking radius is good to go. (I live near an airport so I have a special 2000m unlock circle; skipping this can cause the AC to land abruptly. ~ fear driven check.)
Then I take flight for about 5 more minutes and test the controls and verify no drift and verify the Home Point on the map. This may seem like a lot but in reality those checks take 10 minutes and may prevent a fall out of sky or fly away.  ~ I won't risk it.

I would probably have the world record of fly away for take off with 8 satellite. Lol. Taking of with 8 satellite don't justify getting away by its own without loosing signal. Or the visual sensor are there only for looking good?  

The phantom 1 would take off only with 4 satellite and you couldn't know if there were 4 or 10, it'll fly anyway. DJI has made 8 as the minimum for take off for precaution. It would have to fly with 7,8 or 20. It should not move by it selve unless it is in RTH state or some other automatic mode. This was clearly a failure on the drone. We need to look further it we want to find a root cause for this situations.

davidmartingraf Posted at 2018-3-5 08:17
It is important to note, do you turn your Mavic Air on first then connect the Remote to the Controller or vice versa?

Hi David,

What is the best sequence? I always start with the MA and then the remote controller.

ldgjGuy Posted at 2018-5-15 03:23
Hi David,

What is the best sequence? I always start with the MA and then the remote controller.

I was told by my local DJI Tech who was actually sent to China for specialist training to always first turn on the RC (app on phone, then Controller) and then turn on the MA

Back to the original thread topic the DJI site says - Minimum of 10 Satellites AND 4 bars of signal before take off

ldgjGuy Posted at 2018-5-15 03:23
Hi David,

What is the best sequence? I always start with the MA and then the remote controller.

Always RC first and then the drone.

Glad to know RTH really works automatically at odd situition like this.

ldgjGuy Posted at 2018-5-15 03:23
Hi David,

What is the best sequence? I always start with the MA and then the remote controller.

I start up by powering on the RC first then make sure everything is bound up to the smart device nothing hanging or out of place, then I power on the drone.

I also make sure to put my device in Airplane mode.

davidmartingraf Posted at 2018-5-15 19:12
I start up by powering on the RC first then make sure everything is bound up to the smart device nothing hanging or out of place, then I power on the drone.

I also make sure to put my device in Airplane mode.

My experience runs counter, but I am using a CrystalSky Ultra-brite.
1) Power up Mavic Pro P
2) Wait for MPP to go through its startup
3) Power up CrystalSky Ultra-brite
4) Wait for CS-Ub to show App selection panel
5) Power up Remote Control
- Generally CS-Ub sees MPP through RC, and starts GO-4 App, if not then start GO-4

When I have tried RC first, sometimes CS-Ub does not see MPP, once MPP is powered up.  Forcing a power-cycle of everything.

One advantage to powering MPP up first is it gives MPP more time to lock-on to GPS Sats for a good position fix.

Why did the aircraft start flying sideways to begin with. Before RTH  before he did anything it started flying sideways. This is BS. It should of just hovered where it was.

HedgeTrimmer Posted at 2018-5-15 19:25
My experience runs counter, but I am using a CrystalSky Ultra-brite.
1) Power up Mavic Pro P
2) Wait for MPP to go through its startup

Intuitively remember if you power on your RC last. then it opens up interference issues during the time starting when your drone begins looking for a signal. If your drone is powered on before the RC, then the drone immediately begins looking for and bouncing between the proper signal. If the RC powers on first, then it can put a lock on the drone immediately because the drone has no time to jump in and out of frequencies checking to see which signal matches.

davidmartingraf Posted at 2018-5-15 22:26
Intuitively remember if you power on your RC last. then it opens up interference issues during the time starting when your drone begins looking for a signal. If your drone is powered on before the RC, then the drone immediately begins looking for and bouncing between the proper signal. If the RC powers on first, then it can put a lock on the drone immediately because the drone has no time to jump in and out of frequencies checking to see which signal matches.

Sounds logical, can some one (maybe DJI) confirm this?

Does this help?
https://forum.dji.com/thread-148682-1-1.html

haven't fully pulled the log apart yet.  

taking off with few sat connections does not specifically cause a fly away.  can it?  i guess maybe.. but i never had an issue taking off with few sat connections.   it is better to wait for a solid GPS but fly away events from what i gathered reading tons of posts about it, usually it occurs because poor conditions or internal miscommunication with the drone..   

like with the spark.. 1 system failure can wipe out a bunch of other systems...  mavic has reducancies so it should be ok if 1 system fails, but it depends what system that is and how vital is it and if the other system is functional or suffering the same issues.  

i usually set home point to my iPhone X in the app.. and take off even with few sat connections.. i suggest everyone that is in a hurry to try that out, at least its locked a homepoint on you so even if it only getting a few GPS connections, it can still work its way mostly back.. i actually flown around with 6 connections (didn't get 9+ for entire flight because dense clouds) and still RTH just fine.. landed within 10 feet of where i was standing, but nowhere near where took off from.  

Having only just picked up a Mavic Air and only previously flying FPV quads with no GPS i find the subject and info brought up here brilliant.
Glad you regained control and many thanks for bringing this subject matter up.

I flew 3450ft in an area full of WiFi Interferance. I can flew further but turned around. You just have to make sure there are not obstruction in front of you.

Well tons of posts about GPS this and what the OP should of done and boa boa boa. Guys I'll say again. He said it "took off" in other words accelerated away without any input on the controls. This was not drift due to bad GPS. So where exactly was it going to fly to and why is it flying away without instructions. So the real question is the aircraft code is malfunctioning. You cannot have these things deciding on their own to fly anywhere, I don't care what the GPS says. Something is not right. It must go into a hover and prompt you it must not fly away. Even if it is unstable and drifting a bit that's better than it "taking off" to some place you can't see.

Kevjones1959 Posted at 2018-5-16 06:19
Well tons of posts about GPS this and what the OP should of done and boa boa boa. Guys I'll say again. He said it "took off" in other words accelerated away without any input on the controls. This was not drift due to bad GPS. So where exactly was it going to fly to and why is it flying away without instructions. So the real question is the aircraft code is malfunctioning. You cannot have these things deciding on their own to fly anywhere, I don't care what the GPS says. Something is not right. It must go into a hover and prompt you it must not fly away. Even if it is unstable and drifting a bit that's better than it "taking off" to some place you can't see.

Yeah, honestly, that's part of why it was so shocking to me. Of all the things I expected it to do, autonomously meandering through the woods was not one of them regardless of the number of GPS satellites or anything else going on, really. I figured it had any number of sensors that could tell it that it was moving, so it really threw me for a loop.

I have since flown it many times, always waiting for at least 13 satellites and it's behaved flawlessly. I will not launch with lower. But it really does make me wonder, especially since it was able to accurately depict its track through the woods in the log. If it knew its location well enough to depict in the log, how could it not have enough data to hover mostly motionless?