IOS via iphone 6s. Set up a waypoint mission within Litchi Hub and the Litchi app. (I spent a lot of time on it too...) The mission is over water near a bay to last 14min. Launched great and about halfway through the mission the Mavic just stopped and hovered. After several min scratching my head I finally hit the RTH button on the controller. BTW, never lost sight of the drone. Any ideas why this happened? Thanks!
If I set a waypoint mission no curves I find it pauses at every waypoint. Even though mission speed is 45kmh. If set curved not a problem. I have also found if I have collision avoidance on it can stop and hover if pointing anywhere near towards the sun.
As codecutter mentioned, most probably collision avoidance. If the you program the mavic to turn towards the sun in your waypoint mission with OA on, it can sense it as an obstacle and come to a stop. I always fly way-point mission with OA disabled for this very reason.
I've come on here to discuss the same thing. So not wanting to thread hijack but I think we common issue and better keeping it in one thread for people to find rather than 2. So I have posted up my video from various circular flights out getting larger and larger. On the 4th trip out doing an 0.5mile route it just stopped mid mission and the controller was moving from 0 to 0.3mph, 1mph - basically sat there. Thinking it was the sun issue (Litchi doesnt tell you of obstacles being detected like the Go app?) instead of cancelling the mission I rotated the mavic toward me and it still sat there thinking for a while before crawling to the final turn then zipping home. Was very worrying and as the point of the day was to get confidence in Litchi missions this threw my confidence big style. I turned off the obstacle avoidance once it landed and kept sending it out and I'm certain it blasted round quicker than all previous "missions".
<< take a look at 4m:05sec --- look familiar?
Big question for me is --- is there a way for us to see exactly why it stopped anywhere? I'm using the free Airdata pro subscription at the moment and there was nothing in there.
And I'm now convinced I shouldn't let it go on a Litchi mission without all obstacle avoidance disabled - What do people think?
Was going to raise it on the Litchi facebook page and see what they have to say considering is cost of £20 for an app and it threw a wobbler on it's first outing.
Big question for me is --- is there a way for us to see exactly why it stopped anywhere? I'm using the free Airdata pro subscription at the moment and there was nothing in there.
And I'm now convinced I shouldn't let it go on a Litchi mission without all obstacle avoidance disabled - What do people think?
Was going to raise it on the Litchi facebook page and see what they have to say considering is cost of £20 for an app and it threw a wobbler on it's first outing.
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@deggers the wind is what is causing your issue. Can be seen by the wind turbines, the water surface on the reservoir and the Mavic props in the video due pitch into wind when the Mavic is slowed up. Fly it again on a day with less wind and it will not grind to a halt.
You may be right but I'm not sure I'm convinced mate. Had my wind meter out and went through 4 batteries and not an issue except for that one flight and looking at air data average wind was 11.4mph and strongest gust 13.9mph. The Mavic got stuck flying EAST. The wind was blowing EAST. Cruise speed was set to 20mph. Therefore I jumped to the conclusion, collision avoidance. The sun was high, there were sun rays on the video footage at points and reflection on a lake?
I didn't have an issue all afternoon except for this one trip. And looking at the gps track for this particular flight the track was all over the place from the start in comparison to the other tracks which were pretty much straight line. The cynic in me tells me something was not right this time round. Is there anyway to get detailed logs out of litchi which will defo say "I was having wind issues"
And with object avoidance disabled it appeared to barrel round in comparison to all previous runs.
Check the squiggly line on that run.
Screen Shot 2017-07-09 at 19.54.28.png
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jimmybbq
Well-Known Member
Pablo
Well-Known Member
Yep I'd say the props were a giveaway there, it was fighting the wind. It's happened to me on Litchi missions too.
I do think it's best to have OA off though, if you've planned the mission properly (and you should have), it will only cause your more problems than it will solve.
I do think it's best to have OA off though, if you've planned the mission properly (and you should have), it will only cause your more problems than it will solve.
Looks like I'm heading towards conceding to wind then
OA will be off for Litchis I think. I can't handle the scare stories of the sun.
I can't deny there is a wind farm up there for a reason.
I was only watching your video on my phone earlier. Now that I have seen it again on a large screen it is definitely a wind issue. You appear to have your directions mixed up. The wind is blowing from the Reservoir toward the wind turbines.
That would make the wind direction a westerly (not an Easterly). The video shows you flying anticlockwise around the circuit which also suggest you were flying West into the wind when you had the low speed issues and the squiggly line on your map . This is logical.
You could pull the log from the aircraft DAT file and it will show you the aircraft pitch while it was struggling to windward. Also Airdata cannot collect wind data when flying in waypoint missions. Therefore if you are after a more accurate wind reading in future you can always do a quick wind sounding flight to test the water so to speak. Take off and hover for at least 5 seconds at say 50', 100' and 200' then return and land. If you then sync the flight the winds will display in Airdata. I suspect the airdata winds you mention are ground weather forecast for time and not the actual observation aloft.Is there anyway to get detailed logs out of litchi which will defo say "I was having wind issues"
Check the squiggly line on that run.
Screen Shot 2017-07-09 at 19.54.28.png
Had you set your mission speed or at least the upwind legs to to 30mph it would have done a better job of it. As I understand it, the mission speed achieved in waypoint mission is limited to the equivalent pitch angle for a given speed in nil wind (or thereabouts). So once your Mavic had reached the pitch for your commanded speed in nil wind it wont pitch more to compensate the head wind & it will eventually grind to a halt..
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Learned a lot so far in this thread as I had a similar situation yesterday too. Been flying litchi missions for a year with no problem and had a super sketchy fail yesterday. Mavi pro and iPhone 7. Flying a mission I'd flown many times before with my p3p, which is beyond LOS and I knew you loose connection for about 3 minutes.
Mavic went up and started the mission fine. Connection lost at the point I expected. But time passed way too long without reconnecting so I had a bad feeling. Jumped in my car and drove a mile up the road and controller re-establish connection. Mavic was just drifting around at 150' about 1/3 through the mission slowly and drunken. The battery was at 30% and usually in this mission it completes it and lands back at home with 70% remaining. (Showing how long it had been on walkabout hovering around).
I flipped into sport mode and raced it to where I was and landed.
Close call!
This has shaken my faith in litchi.
1) wind. Yes it was flying into variable winds from 10-15 mph and I had cruise set at 20mph. I knew I had enough juice to fight headwinds and then scream back home on downwind. I've flown missions before where it was blown backwards at times as it fought gust but it never lost focus on thr way points.
2) Sun. I was flying due west into blinding evening sun. And had sensors on. Never thought this might be an issue.
I guess I can download the flight logs and upload video if someone here is an expert at decoding what went wrong.
But I guess I'll heed the sensor off advice from here on out. I'm.**** about checking my fight routes.
Just seems there have been a lot of horror stories these last few days with litchi missions after all the firmware updates.
The fact that this happened to me when disconnected was what was really scary. It was over water too! Luckily my sixth sense said something was wrong
Mavic went up and started the mission fine. Connection lost at the point I expected. But time passed way too long without reconnecting so I had a bad feeling. Jumped in my car and drove a mile up the road and controller re-establish connection. Mavic was just drifting around at 150' about 1/3 through the mission slowly and drunken. The battery was at 30% and usually in this mission it completes it and lands back at home with 70% remaining. (Showing how long it had been on walkabout hovering around).
I flipped into sport mode and raced it to where I was and landed.
Close call!
This has shaken my faith in litchi.
1) wind. Yes it was flying into variable winds from 10-15 mph and I had cruise set at 20mph. I knew I had enough juice to fight headwinds and then scream back home on downwind. I've flown missions before where it was blown backwards at times as it fought gust but it never lost focus on thr way points.
2) Sun. I was flying due west into blinding evening sun. And had sensors on. Never thought this might be an issue.
I guess I can download the flight logs and upload video if someone here is an expert at decoding what went wrong.
But I guess I'll heed the sensor off advice from here on out. I'm.**** about checking my fight routes.
Just seems there have been a lot of horror stories these last few days with litchi missions after all the firmware updates.
The fact that this happened to me when disconnected was what was really scary. It was over water too! Luckily my sixth sense said something was wrong
@Logger - thanks for taking a good look at it. I'll have a go at pulling the flight data. You are correct wind was E / NE so I was flying W. Also the airdata wind speed and gust was taken at the launch spot which is the highest altitude I was flying from - 100ft ground elevation track. Just struggling to accept on this one and only occasion it didn't zip round it was wind and in my mind I need to be certain it was and not a bug which could cause a loss of the mav in any future mission. See attached links for further info. I'll upload the data if I can get it out of the system later.
Route with wind recorded location
airdata_windspeed.JPG
Airdata windmap @ launch
airdata_windmap.JPG
@MarinFlyer - guess the only way to get a definitive answer is to pull the logs which i will be having a go at this evening because I can accept a wind issue if thats the cause and be cautious going forward but 40% of me is saying, seeing it behave the way it did that you and I and the original poster from earlier this year have had a near identical issue and perhaps something else is going on which actual flight data will answer.
To be continued....
Route with wind recorded location
airdata_windspeed.JPG
Airdata windmap @ launch
airdata_windmap.JPG
@MarinFlyer - guess the only way to get a definitive answer is to pull the logs which i will be having a go at this evening because I can accept a wind issue if thats the cause and be cautious going forward but 40% of me is saying, seeing it behave the way it did that you and I and the original poster from earlier this year have had a near identical issue and perhaps something else is going on which actual flight data will answer.
To be continued....
Pablo
Well-Known Member
I'd also be interested in seeing the .DAT for this flight. Look here for info about retrieving it. It will be large so you'll need to Dropbox or GoogleDrive it.@Logger - thanks for taking a good look at it. I'll have a go at pulling the flight data. You are correct wind was E / NE so I was flying W. Also the airdata wind speed and gust was taken at the launch spot which is the highest altitude I was flying from - 100ft ground elevation track. Just struggling to accept on this one and only occasion it didn't zip round it was wind and in my mind I need to be certain it was and not a bug which could cause a loss of the mav in any future mission. See attached links for further info. I'll upload the data if I can get it out of the system later.
Route with wind recorded location
airdata_windspeed.JPG
Airdata windmap @ launch
airdata_windmap.JPG
@MarinFlyer - guess the only way to get a definitive answer is to pull the logs which i will be having a go at this evening because I can accept a wind issue if thats the cause and be cautious going forward but 40% of me is saying, seeing it behave the way it did that you and I and the original poster from earlier this year have had a near identical issue and perhaps something else is going on which actual flight data will answer.
To be continued....
I've recently uncovered the wind data in the .DAT that the Mavic produces. But, there are some aspects of those wind calcs that don't quite add up. I suspect they are noisy and need to be smoothed a bit. But, they would probably help in a situation with high wind values.
If you want to have a go at it a CsvView beta is available by going to
http://www.datfile.net/DatCon/DatCon.2.6.0.zip
This is a beta and has some issues. But nothing serious. I hope.
The wind calcs signals have names that start with AirComp
@Logger
You are welcome. Sorry to bang on - but you still have your wind terminology back to front. "Wind direction is the direction from which the wind is blowing; the direction from which the air is moving. It is not the direction the wind is blowing toward." (that is straight of google btw) 255 degrees = W / SW
Yeah so at one point in time the wind was 13.9 mph. The problem with your linked Airdata wind is it only managed to grab a single momentary snapshot, and not during actual mission as airdata is incapable of doing that. The video clearly shows a gusty surface wind with bullets blowing across the lake. So the measured 13.9 mph could easily have increased towards 20 mph aloft during the the 10 min period of your flight. Someone with the appropriate knowledge might even be able to accurately deduct the wind speed from those 60 - 80 m wind turbines doing ~ 17 RPM. They certainly aren't idling.
Last flight I did two days ago was taking a panorma with litchi and you can see how the wind strength can vary markedly in a few minutes at a constant height and location. The readings were taken before and after the pano job
@BudWalker Will take a look at your update with the wind fields.That will be a hand addition.
@Logger - Hate to edge on the it wasn't wind side but....
204.820 : 1540443973 : 16779 [L-MIS]WP Mission: received idle vel cmd 8.999998 from app
204.820 : 1540444235 : 16779 [L-MIS]WP Mission: ack idle vel 0 to app
At which point I'm watching it stopped mid air. Hit Pause, repoint it, resume and watch it slowly crawl and pick its speed back up on the turn - as below
244.283 : 1718027935 : 18753 [L-RC]rc cmd:STD_PAUSE_CUR_MIS
244.285 : 1718036495 : 18753 [L-FLYMODE]CTRL rc resume waypoint_mission
244.905 : 1720826740 : 18784 [L-RC]Emergency break. rc vib!
245.045 : 1721457163 : 18791 [L-FMU/LED]type:0, normal flash action:
245.045 : 1721457540 : 18791 [L-FMU/LED]c0:0,1;c1:0,1;c2:0,1;c3:2,3;c4:0,1;c5:0,1;c6:0,1;c7:0,1
^^ and did hit an emergency "break"? - There were no collision warnings on the remote.
It had run this route previously no issues so there wasn't and isn't a pause command in the mission - it has curves so why was it sent an idle velocity command from the app?
I'm trying to reconcile the log to the klm / flight data at the moment to further eliminate wind.
@BudWalker @MarinFlyer
204.820 : 1540443973 : 16779 [L-MIS]WP Mission: received idle vel cmd 8.999998 from app
204.820 : 1540444235 : 16779 [L-MIS]WP Mission: ack idle vel 0 to app
At which point I'm watching it stopped mid air. Hit Pause, repoint it, resume and watch it slowly crawl and pick its speed back up on the turn - as below
244.283 : 1718027935 : 18753 [L-RC]rc cmd:STD_PAUSE_CUR_MIS
244.285 : 1718036495 : 18753 [L-FLYMODE]CTRL rc resume waypoint_mission
244.905 : 1720826740 : 18784 [L-RC]Emergency break. rc vib!
245.045 : 1721457163 : 18791 [L-FMU/LED]type:0, normal flash action:
245.045 : 1721457540 : 18791 [L-FMU/LED]c0:0,1;c1:0,1;c2:0,1;c3:2,3;c4:0,1;c5:0,1;c6:0,1;c7:0,1
^^ and did hit an emergency "break"? - There were no collision warnings on the remote.
It had run this route previously no issues so there wasn't and isn't a pause command in the mission - it has curves so why was it sent an idle velocity command from the app?
I'm trying to reconcile the log to the klm / flight data at the moment to further eliminate wind.
@BudWalker @MarinFlyer
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I look at this stuff all the time. Determining what the eventLog stream is saying is usually difficult if not impossible. If you post a Dropbox or GoogleDrive link to the .DAT then we can get a better idea what's happening with this flight.
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I'm uploading the files now - will post a link when it's complete.
Interesting Litchi sent me a preliminary response "The only way this could happen is if you set the cruising speed to 0 in the mission settings" - the only variation i can see online is that some waypoints are marked with the slider all the way to the bottom "cruise speed" (cruise speed set at 20.1mph) and some waypoints actually stipulate 20.1mph. Aside from wind consideration- still doesn't explain while all flights were faultless except one stretch - waiting for a further response. Very impressed at their response time at the moment.
Interesting. Assuming I am reading @BudWalker 's new fields correctly, on the first lap it looks like the wind peaked at ~ 15mph. Second lap when you ground to a halt it pretty much doubled in strength, increasing all the way up to 33mph (which corresponds with max speed in waypoint mode) and on the final lap it abated back to around 15mph again.
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