I have been doing videos of ghost towns and historic mines in rural NV for well over a year. I use the Litchi software, which allows pre-planned missions. For most of my flights I want curved turns for a smooth video. On many of my missions I lose contact with the drone in mountainous terrain but the drone carries on the uploaded mission mostly autonomous.


And that "mostly" is my problem. Waypoints, curves and altitude changes are aparently stored on the drone and execute fine after I lose the signal. Unfortunately gimbal pitch is not. After I lose contact the gimbal pitch functions "Focus POI" and "Interpolate" no longer work. As a result I get video in the right direction, but too low or too high. I also cannot use the "Tilt Camera" function for each waypoint because "Actions" are not executed for mission with "Curved Turns". In the past I have set the gimbal pitch to a medium value that worked for most of the remaining mission. But for a mission I am working on now I need to re-set the pitch while out of contact.


This seems to be a pretty common requirement and I am hoping that there is a solution I just have not thought of yet. All you gurus out there, any ideas? Thank for your input.

Hello and good day Joerg62. I am sorry for the trouble and thank you for reaching out. I hope that you will get the best information and recommendation from our valued DJI co pilots who used the litchi application when flying there DJI drones. Just a friendly reminder, we don't recommend you to use a third party applications like the Litchi application because we are unable to ensure the compatibility and performance. We do appreciate your understanding and support. Have a safe and happy flying always.

Thank you Stephen. I would love to use the DJI software instead. Unfortunately at the moment it does not support pre-planning missions on the computer and executing them autonomously in the field. Is there any chance this may be added to the DJI software at some point? In many ways the DJI software is superior to Litchi, but the lack of autonomous missions is a real show stopper for me and I am sure for many other users.

Joerg62 Posted at 7-14 11:10
Thank you Stephen. I would love to use the DJI software instead. Unfortunately at the moment it does not support pre-planning missions on the computer and executing them autonomously in the field. Is there any chance this may be added to the DJI software at some point? In many ways the DJI software is superior to Litchi, but the lack of autonomous missions is a real show stopper for me and I am sure for many other users.

You are very much welcome Joerg62. Thank you for sharing these information and your insights wit regards to this matter. I will forward these information to the designated DJI department for further development of the DJI Go 4 application. If you have any other inquiries and concern with DJI. Please feel free to post it here at DJI Forum we are here to help and support you.

Back to my original question: Has anyone figured out how to control the gimbal pitch in a Litchi mission while using "Curved Turns" and out of controller range?

You might consider operating the gimbal pitch manually and blindly from your controller .  After all, at least early on after the disconnect, there is a strong possibility that you still have the control signal reaching the AC, even if the app is showing disconnected.  Adjusting the gimbal pitch blindly would be tough though, obviously, since you don't know where you are.  A GPS device on the drone might help?  But you'd need cell towers.  

You could also figure it out by timing by doing a dry run first.  

Another idea, mod the controller so that you have a significantly stronger control signal and also a significantly more sensitive receiving antenna.  Good flat panel directional antennas and amps.

Another idea, get an antenna mast for the control side.  Height always helps.  You'll need good cable.  And an amp too most likely.  PITA for sure.  

Another idea, get a couple P2's or P3S's.  Use one to fly with.  The other to relay the signals.

http://redbirdrf.com/

Good luck

Joerg62 Posted at 7-14 12:21
Back to my original question: Has anyone figured out how to control the gimbal pitch in a Litchi mission while using "Curved Turns" and out of controller range?

I am planning to fly a number of Litchi missions along the route of an old railway, but I was going to set the gimbal pitch manually to a particular angle, so I set gimbal pitch to 'disabled' in the waypoint settings so that it does not change. Would that work for you?

Mark The Droner Posted at 7-14 14:05
You might consider operating the gimbal pitch manually and blindly from your controller .  After all, at least early on after the disconnect, there is a strong possibility that you still have the control signal reaching the AC, even if the app is showing disconnected.  Adjusting the gimbal pitch blindly would be tough though, obviously, since you don't know where you are.  A GPS device on the drone might help?  But you'd need cell towers.  

You could also figure it out by timing by doing a dry run first.  

I have modified my controller with external directional antennas and amp. But you can't beat physics. I am going over a ridge and then a few hundred feet down on the other side, close to the mountain. No amp is gong to reach the drone there. But I like your idea of having a second drone for a repeater. That may just be the ticket. Thanks for the tip. Much appreciated.

Geebax Posted at 7-14 14:50
I am planning to fly a number of Litchi missions along the route of an old railway, but I was going to set the gimbal pitch manually to a particular angle, so I set gimbal pitch to 'disabled' in the waypoint settings so that it does not change. Would that work for you?

Thanks for the reply. That is what I did for previous missions. But for this mission I need a near 0 degree pitch and then a 50 degree pitch. I suppose I can try it with an average 25 degree pitch and see what I get. The simulation with "virtual litchi mission" looks acceptable, although far from perfect.

with the curved settings turned on actions can not be activated, ie interpolation being one of the actions litchi doesn't work that way. You can control the gimbal manually or set the mission to fly straight lines, which as you say you don't want. maybe run a curved flight and a straight flight and splice the vid.

Mark The Droner Posted at 7-14 14:05
You might consider operating the gimbal pitch manually and blindly from your controller .  After all, at least early on after the disconnect, there is a strong possibility that you still have the control signal reaching the AC, even if the app is showing disconnected.  Adjusting the gimbal pitch blindly would be tough though, obviously, since you don't know where you are.  A GPS device on the drone might help?  But you'd need cell towers.  

You could also figure it out by timing by doing a dry run first.  

That Redbird device looks interesting. I had often dreamed of having a 400' high tower for my RC antenna, so I could have LOS radio transmission to the lake 2 miles below the mountaintop where I launch from. Trees block my signal, so I cannot get down low along the lake and have to stay at the edge and at 400' to maintain a signal, but with this, I could have a P3 hovering over my roof and I could operate my RC from the comfort of a lawn chair instead of climbing up on my roof to get some range. I'll bet this would give me several miles of range.

I have found once signal is lost the gimbal is where it is until signal is regained.

Edward J Smith Posted at 7-17 06:15
I have found once signal is lost the gimbal is where it is until signal is regained.

I've heard that said and in theory it makes sense -- but I can never execute it.  If POI's are set, the gimbal will fight any change you try to make, so timing that angle with the loss-of-signal is nearly impossible

In which case you're better off forgetting POI's and just setting the pitch for an average angle, as was mentioned above.

  I have been doing videos of ghost towns and historic mines in rural NV  for well over a year. I use the Litchi software, which allows  pre-planned missions. For most of my flights I want curved turns for a  smooth video. On many of my missions I lose contact with the drone in  mountainous terrain but the drone carries on the uploaded mission mostly  autonomous.


And that "mostly" is my problem. Waypoints, curves and altitude changes  are aparently stored on the drone and execute fine after I lose the  signal. Unfortunately gimbal pitch is not. After I lose contact the  gimbal pitch functions "Focus POI" and "Interpolate" no longer work. As a  result I get video in the right direction, but too low or too high. I  also cannot use the "Tilt Camera" function for each waypoint because  "Actions" are not executed for mission with "Curved Turns". In the past I  have set the gimbal pitch to a medium value that worked for most of the  remaining mission. But for a mission I am working on now I need to  re-set the pitch while out of contact.


This seems to be a pretty common requirement and I am hoping that there  is a solution I just have not thought of yet. All you gurus out there,  any ideas? Thank for your input.

I have been continulously frustrated by this exact issue and have yet to find a satisafactory solution.

Question: Actions settings do not load on to the drone, we know this -- but I think, your heading setting does.  So, picking an average pitch/angle of the camera and turning your heading to correlate with the POI's you wanted to use, might work pretty well and be the closest remedy.  


Right?

Bluehook Posted at 7-21 09:04
I've heard that said and in theory it makes sense -- but I can never execute it.  If POI's are set, the gimbal will fight any change you try to make, so timing that angle with the loss-of-signal is nearly impossible

In which case you're better off forgetting POI's and just setting the pitch for an average angle, as was mentioned above.

That is what I do.

I’ve done a little Litchi flying and your explanation of gimbal pitch control loss with signal loss explains a couple of situations I couldn’t explain otherwise.

I have also done some GSPro flying but not recently enough to remember whether it does gimbal pitch. Every GSPro mission I have flown was for 3D mapping and it looked straight down.

If signal is lost during a Litchi mission the aircraft will continue the mission at the speed it was travelling at when it lost signal. Gimbal tilt will also remain at the last position it was at when signal was lost. The aircraft MUST have controller signal for the aircraft to make changes in speed or gimbal tilt even though they were programed into the aircraft mission. Aircraft heading changes will still be made if signal is lost.  

Bluehook has the best solution for planning a mission.

When you say pre-planned do you mean with the aircraft powered off?  I've been looking for a way to do this

Charlie  Phantoms Posted at 7-21 13:17
If signal is lost during a Litchi mission the aircraft will continue the mission at the speed it was travelling at when it lost signal. Gimbal tilt will also remain at the last position it was at when signal was lost. The aircraft MUST have controller signal for the aircraft to make changes in speed or gimbal tilt even though they were programed into the aircraft mission. Aircraft heading changes will still be made if signal is lost.  

Bluehook has the best solution for planning a mission.

My own experience with Litchi seems to be different.  The speed will change on my missions just fine per the pre-programmed mission.  It doesn't seem to matter whether the AC senses a control signal.  However, I acknowledge there is a possibility that the AC is still sensing the control signal on my missions even after the app indicates a disconnect and there is a loss of FPV/telemetery.  I am not sure how one would know that the control signal is definitely lost during a Litchi mission without deliberately trying to interrupt the mission blindly.  

djiuser_gWMtW97MTQl9 Posted at 7-21 15:52
When you say pre-planned do you mean with the aircraft powered off?  I've been looking for a way to do this

You can go to the Litchi site, sign in, plan a mission, save it under a clever name such as best_mission_ever, upload it to your app.  Then later prepare to fly, load the mission to your AC,  launch said mission, and then sit back and watch the magic unfold on a fresh 100% AC battery.

Good luck

Mark The Droner Posted at 7-21 16:34
My own experience with Litchi seems to be different.  The speed will change on my missions just fine per the pre-programmed mission.  It doesn't seem to matter whether the AC senses a control signal.  However, I acknowledge there is a possibility that the AC is still sensing the control signal on my missions even after the app indicates a disconnect and there is a loss of FPV/telemetery.  I am not sure how one would know that the control signal is definitely lost during a Litchi mission without deliberately trying to interrupt the mission blindly.

"I am not sure how one would know that the control signal is definitely lost during a Litchi mission "
On the Phantom 4 Pro the green light on the controller will turn red.

For those of you who don’t know, Mark The Droner is the Litchi wizard. Just watch some of his videos.

Never heard of Bluehook. Sounds promising.

Edward J Smith Posted at 7-21 17:53
"I am not sure how one would know that the control signal is definitely lost during a Litchi mission "
On the Phantom 4 Pro the green light on the controller will turn red.

No - think about it.  I'm referring to the control signal and just the control signal.  That's the signal that moves from the controller to the AC.  

PilotPete Posted at 7-21 18:51
For those of you who don’t know, Mark The Droner is the Litchi wizard. Just watch some of his videos.

Never heard of Bluehook. Sounds promising.

No sir, not a wizard.  I'm a novice trying to learn from the more-experienced and the experts.

Litchi is intriguing to me -- I'll be sure to check-out Mark the Droner and I'll suggest all Litchi enthusiasts check-out fellow DJI forum user @Dirty Bird  and his youtube channel at:

https://www.youtube.com/user/Schtuperman/videos

He is an amazing engineer of the Litchi app and a really nice guy to boot.  He has helped and advised me several time here, which as been a true honor.

Bluehook Posted at 7-21 09:10
I have been continulously frustrated by this exact issue and have yet to find a satisafactory solution.

Question: Actions settings do not load on to the drone, we know this -- but I think, your heading setting does.  So, picking an average pitch/angle of the camera and turning your heading to correlate with the POI's you wanted to use, might work pretty well and be the closest remedy.  

Litchi loads the mission into the drone, actions do load with the mission created but only work with straight path missions. Curved flight missions can not use actions, except for the first and last waypoints to start and end video recording.
To use gimbal pitch in curved path missions you set a series of poi's along the path of the mission flight, and use the relative elevation of each poi to control the gimbal. The poi's elevation is set by default to 3 ft. You can change the height of where the gimbal will focus on the chosen poi by raising the poi elevation height or lowering it to whatever you choose.

Say your chosen poi is 20ft tall, the poi's default height is agl 3ft, but you want to focus on the agl 10 ft portion of the poi, you set the poi elevation to agl 10ft and the gimbal will move to focus on this approx point, due to the map data it uses. You do this in the poi settings, this happens during flight from waypoint to waypoint. This means if your drone is flying from wp 2 to wp 3 and your chose poi 6 to focus on at agl 6ft, as the drone flies to wp 3 the gimbal will start to focus on poi 6 as it flys from wp 2 to wp 3. say you flight from wp 1 to wp 2 is north to south your wp agl is 100 at wp 1,   you choose agl 5 for poi 8 for wp 2 and you want to climb to agl 250 the gimbal will then start to focus on agl 5 on poi 8 as the drone flies from wp 2 to wp 3 as it climbs to 250 agl. the drone then flies on to wp 3 and so on with smooth cinematic transitions. hope that's not to confusing. It really works and looks good.

Actions allow you to start stop recording vids, take pics, set interpolations etc but only with straight path flights you can set actions to yawl or turn right or left climb or lower as it flies, or you can manually control those actions instead of using actions.

Litchi is very powerful, you can use the web portal or the app to create missions, the web portal is where you can set all the controls for curved missions, and set actions for straight path missions. hope that helps. phantom film school on udemy will teach you how to do this and lots more.
Hoping to go out to meteor crater if the winds die down and shoot a curved flight. it's so windy here I get out once a week or once every 2 weeks.

Mark The Droner Posted at 7-22 02:12
No - think about it.  I'm referring to the control signal and just the control signal.  That's the signal that moves from the controller to the AC.

I thought that if the AC is connected to the RC the light will be green
if it is connected the it is sending and receiving signals if it is red it is disconnected not receiving a signal from the AC.  I guess I'm not understanding what you mean by "control signal".

Edward J Smith Posted at 7-26 13:59
I thought that if the AC is connected to the RC the light will be green
if it is connected the it is sending and receiving signals if it is red it is disconnected not receiving a signal from the AC.  I guess I'm not understanding what you mean by "control signal".

There are actually two signals even if there seems to be one.  One signal is transmitted from the controller and is received by the AC.  Another signal is transmitted from the AC and is received by the controller.

The outgoing control signal is relatively simple.   But the incoming signal is much more complex, it has video data and telemetry.  It carries much, much more data.  And because of that, it is more susceptible to signal loss problems.  

If you fly your AC out quite a ways, you will eventually lose signal.  But what you are likely actually losing early on is the incoming signal.  Chances are better than even that the outgoing signal is still being received and the AC is still responding to your controller input, even if your app says DISCONNECTED.  

The fact is, there is no way for your controller to know whether your outgoing control signal is being received by the AC or not.  So the lamp on the controller and the app as well is likely giving you false info - especially early on after the so-called disconnect.  

Have doubts?  Put a GPS device on your AC and test this.  Fly out until you lose your incoming signal and the app says DISCONNECTED while the lamp on your controller is red.  Watch the AC in your GPS device app continue to respond to your controller.  :-)  

Mark The Droner Posted at 7-26 15:13
There are actually two signals even if there seems to be one.  One signal is transmitted from the controller and is received by the AC.  Another signal is transmitted from the AC and is received by the controller.

The outgoing control signal is relatively simple.   But the incoming signal is much more complex, it has video data and telemetry.  It carries much, much more data.  And because of that, it is more susceptible to signal loss problems.  

OK that makes since but, I have loss signal , red light on, and checked the video footage and the bird  had stopped responding to any command I was sending at that point on the map where it lost signal and returned home so it is not a GPS checker but I do get to see it with my own eyes when I downloaded the footage.

Sick Dog Posted at 7-22 19:28
Litchi loads the mission into the drone, actions do load with the mission created but only work with straight path missions. Curved flight missions can not use actions, except for the first and last waypoints to start and end video recording.
To use gimbal pitch in curved path missions you set a series of poi's along the path of the mission flight, and use the relative elevation of each poi to control the gimbal. The poi's elevation is set by default to 3 ft. You can change the height of where the gimbal will focus on the chosen poi by raising the poi elevation height or lowering it to whatever you choose.

That's all good and thanks for your response but the issue continues to be that the gimbal pitch angle is not right after the drone disconnects from the RC.  

The AC will turn in the direction of the POI but not tilt the camera.

As far as I can tell, the ONLY (near) solution to this is to pick a median gimbal tilt and lock it in.  One of the ways to lock it in would be to eliminate POIs and choose headings manually.  I'm sure there are other ways around.

PilotPete Posted at 2019-7-21 11:55
I’ve done a little Litchi flying and your explanation of gimbal pitch control loss with signal loss explains a couple of situations I couldn’t explain otherwise.

I have also done some GSPro flying but not recently enough to remember whether it does gimbal pitch. Every GSPro mission I have flown was for 3D mapping and it looked straight down.

So far I've not heard of 'any' software program to allow dji spark to fly missions for 3D mapping. It sounds like you're using GSPro for that? What kind of success are you having? Are you getting reliable contours? Do you use Ground Control Points? Do you have any product you can show me?

yogiji Posted at 11-23 17:28
So far I've not heard of 'any' software program to allow dji spark to fly missions for 3D mapping. It sounds like you're using GSPro for that? What kind of success are you having? Are you getting reliable contours? Do you use Ground Control Points? Do you have any product you can show me?

You may be over tasking the Spark to fly mapping missions and get good data.

Mechanical Shutter and 20mp camera on the P4Pro V1 and V2 as well as the Advance would get you where you are looking to be.  
If you need survey grade mapping, then open your wallet to the tune of 15 large or more.

Aerial Traffic
Randy

Coming into this thread somewhat late, I'm afraid. Did you succeed in solving the problem?  I love Litchi and have pre-programmed quite a number of missions with it. All successfully completed even when signal was lost, I'm relieved to say.  You mention in your mission plan, flying up over a ridge and down the other side, before returning. Has anyone suggested starting the mission from a point on the ridge, and flying a figure eight mission down both sides?  That way you'd be at the high point and most likely maintain signal throughout the flight. Or is the ridge inaccessible?  In which case that's my idea out the window

Unfortunately I have not found a good solution for this. And I suspect there is none. For the most part I am still using a fixed medium pitch angle as a workaround. I believe this is a limitation imposed by the drone, not the software. As for the ridge, it is not easily accessible. I was able to fly the mission from the other side of the mountain range, pushing the drone's battery range. On the way back I ran out of juice and went down into terrain. But I was able to recover it and send it in for repairs. Here is the video (minus the crash)