Litchi Waypoint Mission - gimbal pitches up and down continously

[georgem1956]

I'm trying to create a waypoint mission using the Litchi App over our local golf course, which is closed to replace the greens. I want to fly over the greens every 3 days or so to watch the progress as they grow in. My problem is when I fly the mission the gimbal continuously pitches up and down. I end up aborting the mission. I can attach the csv file of this mission if anyone might know what's going on or would like a look at the mission.


Thanks,
George

 

[Ed_2020]

I've experienced gimbal problems when I lost radio contact during the mission (Litchi can't control the gimbal in such case).

Maybe your signal was going on & off, every time the signal is recovered, Litchi will set the gimbal to the planned angle, when signal is lost, the gimbal returns to 0 degrees.

 

[Logger]

Yeah try doing it with the gimbal programmed at a fixed angle to see if that fixes things. Make a copy if the mission, change any Focus POI WPTs to interpolate. Then adjust things so your path takes you over each green allowing you to view it with a fixed gimbal angle of say -15. In this way you should be able to get most of what you want without being reliant on continuous gimbal adjustments. It will not be thwarted by signal loss.

 

[Cut.Aussie]

If you have an iPad, use the free DJI GS Pro app, works great

 

[Logger]

DJI GS Pro does not currently do POIs does it. Not that he needs them if he overflies the greens.

 

[vertigo235]

Yeah, this happens if your RC loses connection to the mavic. Gimbal control is done by the app so you have to have a strong connection if you are using the focus functionality if litchi.

 

[georgem1956]

Ok, sort of makes sense with signal loss however the gimbal starts acting erratic no too far into the mission, relatively close to the RC. I notice when just starting the mission the video signal deteriorates significantly, the point of not being able to see clearly through the camera. So, definitely a strong signal source from somewhere. I've not been very happy with Litchi's app. I don't get this signal problem the the DJI GO4 app. Not sure why there's a difference. I only use the Litchi app for waypoint missions, for that it's pretty handy.

I'll take Logger's advice and switch to interpolate. That should do the trick. Thanks All for your help.

George

 

[dwallersv]

Before you get down on Litchi and decide it's just a crappy app and that's the reason you're having problems, remember that thousands of people are using it and having none of these issues.

The problem is something with your setup and/or locale, and given what Litchi can do for you I'd say it's worth trying to figure out what's wrong with your unique situation.

 

[georgem1956]

Hi dwallersv,
Yes I'm sure it's something locally interfering with the link between the RC and the Drone. To make matters worse, I'd set everything to interpolate, per Logger above. I used the mission hub to set up the course and checked everything over for correctness. I downloaded the waypoint config onto my RC, but it hung up trying to load the waypoint config onto the drone. It sat at "Loading" 0% for 10 minutes. I finally decided to restart everything so I closed the Litchi App (Android version) then my drone started up and took off!
I now have no control over the drone as I watch it fly away! I quickly reloaded the app which showed connected in "navi' mode although not completely connected as I show 0% battery. I hit "Return to Home" which did not work. I pulled up the GPS map which showed the drone had stopped about 1800ft away at an altitude of 154ft (the originally programmed altitude). I could not cause any change in altitude, direction or speed of the drone. Fortunately it was just hovering. Being on a golf course I hopped in a golf cart and tracked it down using the GPS map, showing the drone's position and mine. I found it hovering over a pond and after fiddling around with the different flight modes got it in "Course Lock" and was able to move it forward and backward. Nothing else. So I moved it forward over a wide open fairway thinking that when the battery ran out it would land without problems.

Happy ending! Just on a whim I hit the return home button again and this time it worked. I retrieved the drone with one battery charge LED lit. Lucky! Lesson learned here is that if a restart is necessary, TURN OFF THE DRONE FIRST!

I don't know why the upload didn't work. Probably due to radio interference. There are several Long Range (Tall) antennas within a mile of the course. Perhaps that's the source of the interference. It's uploaded at the same location before, although it does seem problematic. Loading the waypoint course doesn't seem to ever be an immediate action, no matter where I'm located. There always seems to be a varied amount of delay before the upload to the drone happens.

I know the Litchi app is used successfully by many, however my confidence with it has slipped with this episode. I was completely not expecting a partial upload of the program and for the drone to simply take off by itself. I've been using the app for a while, first with my phatom 4 and now with my Mavic. I've never had this happen to me. I was lucky to be able to recover the drone. I'm going to give it another try for the course flyover. I've split the mission into two parts, front nine and back nine. I kept getting a warning that the waypoint course was beyond some range, although I'd set my maximum safe range to well outside the boundaries of the golf course. So I'll try it again. If I still can't get it to work I'll have to go back to DJI GO4 and do it the hard way, fly and mark waypoint, fly and mark next way point, etc. very tedious...

George

 

[dwallersv]

Hey George, I'd give up on it eventually too, just to be clear. However, in the end it may just be that location -- too much radio interference, nothing you can do about it.

I've had similar problems to what you're describing on Android. The problem was the aircraft firmware. I had seriously bad connection and streaming video issues when I updated the Mavic to .700 firmware. Went back to .400, everything was perfect again. That's where I still am.

Unfortunately, DJI has removed .400 from their servers. If you do want to try and flash back to that and see if it solves your problems, @adiru created a Virtual Machine with the .400 firmware cached in DJI Assistant 2 in the VM, and you can use that to get back to .400 if you want to. It's a bit more complicated than usual, though, and you'll have to past the VM step first -- which is easy if you're familiar with the technology, harder if you're not.

I'm pretty sure you can resolve this, if the features of Litchi are important and valuable to you.

Here's a mission I ran autonomously, most of it disconnected. This was nothing production -- I was playing/testing Litchi features, so the composition (shot angles, pans, etc.) are pretty rough. Still, can't do anything like this with GO4.

Perhaps to whet your appetite further, here's a thread I started discussing mission planning techniques and tools, demonstrating how to take a Litchi mission, view it in 3D in Google Earth, and fly it virtually there.

All of this was pre-Mavic; I flew this with my P4, so the theads/postings are over on the PhantomPilots board.

Anyway, check out the thread: Litchi: New terrain-following workflow

 

[georgem1956]

God I love the clarity of these cameras! Got ask, where was this shot? Love the mansion with the pool, tennis court and the rough looking, industrial neighborhood. Very nicely done. Very much liked the pan/reveal of the valley! Very pastoral including the guy mowing, I don't know, what is this place (the first valley)? Lot's of great imaging.

I think about going back to .400. I'm running Mac's so have to scrounge up a laptop somewhere to do it on...


thanks,
G

 

[dwallersv]

Scotts Valley, CA.

That mission was near the High School.

 

[georgem1956]

Hey dwallersv, I switched to a different phone, same operating system, and it worked much better. I stopped using it as a phone due to way insufficient internal memory. But it runs Litchi and worked as it was supposed to. I was able to fly both missions and see where the tweaking is needed. For some reason I just saw the rest of your post about the new terrain following work flow. Going to dig into that right now and refine my mission. Right now I'm flying it at higher altitude than I think it needs to be since there are a quantity of large trees to avoid. If I can get a google 3d look at the path perhaps I can adjust some of the altitudes.

Thanks,

 

[georgem1956]

The google 3D workflow tool was excellent. I was able to catch problems and correct on both front and back nine missions. Thanks!

 

[dwallersv]

Glad this worked for you!

Just a note of caution, the mapping data in Google Earth isn't super accurate, especially regarding trees. Obviously it's not total garbage, as the real world looks pretty close to the 3D representation, especially relative sizing, etc. The ground elevation data for open surfaces (grassland) is pretty good.

So don't rely on GE to be accurately showing you a 20' clearance vertically or laterally from a tree... 50-100' is about the minimum I'm comfortable with.

 

[georgem1956]

Yeah, I figured....no, I've been able to visualize the path and more importantly the coverage of my points of interest. This method revealed several important adjustments to the missions which saved me lots of time! Great tool!

Thanks,

 

[BuyANet]

I was just uploading a video to ask the exact same question! Did my first POI mission where I lost RC contact and noticed in the video the camera goes kind of haywire (pointing straight down, then straight forward etc) until RC contact was reestablished. So setting to interpolate should fix it if setting a fixed angle? Whats the best way to find the right angle? Trial and error?

Check out my video ... RC contact gets lost at 1:31 and regains at 2:29 ...

 

[dwallersv]

The gimbal is controlled directly by the Litchi app running on your smart device. You must have a connection to the aircraft for gimbal tilt to change between waypoints. Once you lose the connection, the mission continues with whatever angle the gimbal was at when you lose contact. Note that this could be an angle you haven't set, as it was transitioning from one angle to another smoothly between waypoints.

So, when gimbal control is important, you can not fly the mission disconnected.

This is a limitation of the DJI SDK, and nothing Litchi can do anything about. Hopefully in some future release DJI will add gimbal control to the automation engine and expose it in the SDK.

 

[BuyANet]

The gimbal is controlled directly by the Litchi app running on your smart device. You must have a connection to the aircraft for gimbal tilt to change between waypoints. Once you lose the connection, the mission continues with whatever angle the gimbal was at when you lose contact. Note that this could be an angle you haven't set, as it was transitioning from one angle to another smoothly between waypoints.

So, when gimbal control is important, you can not fly the mission disconnected.

This is a limitation of the DJI SDK, and nothing Litchi can do anything about. Hopefully in some future release DJI will add gimbal control to the automation engine and expose it in the SDK.

If that's the case, then why did my camera go up and down and stuff when it was disconnected? Check out the video above in my earlier reply.

 

[Logger]

..So setting to interpolate should fix it if setting a fixed angle? Whats the best way to find the right angle? Trial and error?
..

You could use your focus POI calculated Gimbal Pitch angle as a starting point. It is displayed in the WPT info.

If that's the case, then why did my camera go up and down and stuff when it was disconnected?

Good point. Perhaps what we see as being disconnected is actually some degree of signal getting through and this causes the gimbal to go haywire as it attempts to regain referernce. Litchi does not deal with this well, hence the suggestion of doing the simple fix and setting a fixed angle and consecutive WPTs for the possible no comm segments.