Litchi lost signal question

[jmagee]

I've a rather odd uestion that might not have been asked before.

There is an inaccessible landscape feature about half a mile from where I can take off, and I want to photograph it on Litchi waypoint mission. In order to save battery power, I plan to fly to the feature using cruising speed, with a speed of about 25mph as the cruising speed, then for flying around the feature I wnt to photograph, selecting a custom speed of about 1mph or so, then for the last waypoint at the feature (ie: beginning to return home) selecting the cruising speed again.

What is worrying me is, if the craft lost signal while it was executing one of the custom 1mph waypoints, would it know to switch to the cruising speed once it got to the appropriate waypoint, or would it be 'stuck' at the speed it was going when it lost the signal?

I'd be very grateful for any advice here: if it got stuck at 1mph when it had half a mile to go, that would be half an hour's journey and the battery would give out.

 

[GrammatonxXXxCleric]

I believe the app gives a warning at initiation menu. I can't remember just what it said. Make a cruise/custom speed mission and try to initiate it. You'll see the warning.

 

[GrammatonxXXxCleric]

One option is to plan waypoint mission with one speed. Fly to the area of interest. Press pause. At that point pulling/pushing the right stick will move drone along the mission path at what ever speed you press/pull the stick at. You can move it forwards and in reverse along the path. You can pan around, take pics. When finished, press play again or just stick control speed along the same mission path.

 

[Mallettron]

Why not use the cruising speed slider for each waypoint, fast till you get where you want then slow it down?

 

[GrammatonxXXxCleric]

Why not use the cruising speed slider for each waypoint, fast till you get where you want then slow it down?

Because he was worried if drone lost signal at what speed the drone was traveling at, if it lost signal at say 1 mph custom speed would it continue for rest of mission at 1 mph (if it ddn't regain signal) the mission time would exceed battery time. I think the warning when custom speeds are set does say that. (Can't remember)

 

[With The Birds]

You will find litchi help to be a valuable resource.

Warning This setting is only in effect when the aircraft is in range of the remote controller. If signal is lost during the mission, the aircraft will continue the mission at the speed it was travelling at when it lost signal.

 

[stones]

You will find litchi help to be a valuable resource.

Warning This setting is only in effect when the aircraft is in range of the remote controller. If signal is lost during the mission, the aircraft will continue the mission at the speed it was travelling at when it lost signal.

That makes me second guess what I thought Litchi does when you fly autonomously. When you initiate the waypoint mission, you are uploading to the AC, that mission. Literally, it should fly that mission with no input, whatsoever, until it completes it. At least, that's what I always thought. I've read many times how Litchi will complete the mission, if it loses connection with the controller. Why would it do all that what was uploaded to the AC but, not the speed settings?

 

[GrammatonxXXxCleric]

Do a test. Plan a mission with various speeds (close by in view and safe). Initiate mission, turn controller off. Watch it pass each way point and various speed setting way points. Observe what speed it maintains throughout. Turn controller off at different times. Does the drone proceed at same speed or does it change speed to match mission?

 

[With The Birds]

That makes me second guess what I thought Litchi does when you fly autonomously. When you initiate the waypoint mission, you are uploading to the AC, that mission. Literally, it should fly that mission with no input, whatsoever, until it completes it. At least, that's what I always thought. I've read many times how Litchi will complete the mission, if it loses connection with the controller. Why would it do all that what was uploaded to the AC but, not the speed settings?

No second guessing required. The functionality that can be uploaded is limited. Speed changes, certain gimble actions etc are sent to the AC in real time (Autoflight logic was doing this long before litchi with their custom flight controller). You may have noticed that focus interpolation and other actions also fail to operate properly during LCMC. If you loose signal the mission will continue at whatever the current speed is. Fact.

 

[stones]

No second guessing required. The functionality that can be uploaded is limited. Speed changes, certain gimble actions etc are sent to the AC in real time (Autoflight logic was doing this long before litchi with their custom flight controller). You may have noticed that focus interpolation and other actions also fail to operate properly during LCMC. If you loose signal the mission will continue at whatever the current speed is. Fact.

At least now I know. Thanks!

 

[Pharm]

...Why would it do all that what was uploaded to the AC but, not the speed settings?

Because the DJI SDK doesn't allow it. Litchi can only work within those confines. This also applies to pre-programmed camera movements (Custom gimbal angles, POIs, etc.).

 

[With The Birds]

Because the DJI SDK doesn't allow it. Litchi can only work within those confines. This also applies to pre-programmed camera movements (Custom gimbal angles, POIs, etc.).

Nice echo....

 

[Pharm]

I've a rather odd uestion that might not have been asked before.

There is an inaccessible landscape feature about half a mile from where I can take off, and I want to photograph it on Litchi waypoint mission. In order to save battery power, I plan to fly to the feature using cruising speed, with a speed of about 25mph as the cruising speed, then for flying around the feature I wnt to photograph, selecting a custom speed of about 1mph or so, then for the last waypoint at the feature (ie: beginning to return home) selecting the cruising speed again.

What is worrying me is, if the craft lost signal while it was executing one of the custom 1mph waypoints, would it know to switch to the cruising speed once it got to the appropriate waypoint, or would it be 'stuck' at the speed it was going when it lost the signal?

I'd be very grateful for any advice here: if it got stuck at 1mph when it had half a mile to go, that would be half an hour's journey and the battery would give out.

For what you have in mind, you don't need to slow down. The Phantom will stop at each waypoint and complete the action you've specified (IF you have it set to "straight line" and not "curved paths". It will NOT complete the action if there is a curve at that waypoint (curved paths) because the bird will never actually reach that waypoint - it will fly NEAR it instead. For an action to initiate, the bird has to actually reach the given waypoint).
If your waypoints are several yards apart and the speed is set to 25 mph, it will move quickly between them but it'll never get to 25 mph between them. When it stops to take a picture, it'll stabilize the motion before it shoots so motion blur shouldn't be an issue.

Personally, I'd plan a test flight around the area and watch your connection telemetry. If all looks good, then plan your real mission and try to slow it to 10 mph for the picture taking. If it loses contact, it'll still return at 10 mph.

 

[Pharm]

Nice echo....

My explanation was better. Apparently your post was the only one I didn't read. As far as your apparent attempt to make me look stupid, don't bother. I do a quite adequate job of that without your help.

 

[With The Birds]

My explanation was better.

I suspect you truly believe that.

 

[Pharm]

I suspect you truly believe that.

As do my millions of adoring fans. What's that sound? Oh, just another Pulitzer prize being dropped off on my doorstep.

 

[jmagee]

Some very good advice here. In particular, the comment about pausing the mission. I knew that you could take over manual control by flipping from F to P, but of course, that would abort the mission. And I also knew that you could press the arrow on Litchi to pause the mission. But I never knew that you could pause a mission then use manual input to vary the speed along the mision track, or even yaw the craft around. That's fantastic.

Another good piece of advice was suggesting running a test mission that mixed speeds, keeping the craft close to you, then switching off the controller to simulate a lost signal situation. Don't know why I hadn't thought of that - it's so obvious.

Anyway, thank you to all.

 

[GeoffJ]

A word of caution.
If you're running under Litchi control and your aircraft loses signal, it will complete the mission.
Therefore, you need to ensure that the mission will get it back to within signal range.
If the mission is a POI Orbit for example, if it loses contact with the RC, it will just continue to orbit until the battery gets critical, whereupon it will land where it is. That's what the manual says, I haven't tested it however. So you'd better not be orbiting a ship or an island and lose contact.
I'm not sure why it won't RTH at 30% for example.

 

[smiller]

If you are on a waypoint mission and battery reaches 30% (either connected to the controller or not), with the aircraft RTH or just continue the mission until critical battery and then land?