Single Axis movement, keep subject in center

[D3D]

I would like to fly over a subject in a straight line and keep it in the center the entire time (see pics). It would be fine if it was the drone that tilted or the gimble that moved, and the drone could fly straight or arc. In Litchi using Focus mode you can almost do it if you approach the subject flying forward, but as soon as you pass over the gimble can't track any further. If this can't be done on the fly is it possible to set up a KML template (or something) that you could load into a variety of situations?

 

[ratjr15]

I believe if you create a waypoint mission over the subject with gimbal set to focus poi and POI on your subject, the ac will rotate and move the gimbal to give you this result. Ive done it without intending...

 

[D3D]

I'll do some experimenting in that direction. Do you think it would tilt the aircraft too or just the gimbal? I don't think that gimbal movement alone will do what I need although I if its side to side movement I could be wrong.

 

[ratjr15]

This is essentially what I was talking about though I'm not sure it's exactly the result you're looking for...

 

[brett8883]

I would like to fly over a subject in a straight line and keep it in the center the entire time (see pics). It would be fine if it was the drone that tilted or the gimble that moved, and the drone could fly straight or arc. In Litchi using Focus mode you can almost do it if you approach the subject flying forward, but as soon as you pass over the gimble can't track any further. If this can't be done on the fly is it possible to set up a KML template (or something) that you could load into a variety of situations?

I just did some tests for you and you can do this with focus mode but you have to set Aircraft Rotation to “Auto.”
I also had to change the joystick reference so that when the drone turns around I can continue to push forward instead of switching to pulling it back.

However, I was more pleased with how it worked using waypoints and setting a focus POI.

 

[D3D]

Cool thanks, I will check that out tomorrow. I just went out and created a 2 point waypoint mission with a POI in the center and tried a few different things, none of which really got me what I wanted. The closest I came is with the video below. In this video the drone is facing in the direction of flight and then rotates half way though and flies backwards. Ideally the drone would fly sideways and tilt to keep things in the center.

 

[brett8883]

Cool thanks, I will check that out tomorrow. I just went out and created a 2 point waypoint mission with a POI in the center and tried a few different things, none of which really got me what I wanted. The closest I came is with the video below. In this video the drone is facing in the direction of flight and then rotates half way though and flies backwards. Ideally the drone would fly sideways and tilt to keep things in the center.

You have set the rotations to managed and heading to custom in the mission settings. I also always have a starting way point that's just an extra waypoint and my mission really starts at waypoint #2 so I had three waypoints in my mission. I don't have a great reason why I do this nor an explanation for why this would help but when I did it it was perfectly how you want it so play with your way point settings. Its possible to make it how you want with

 

[brett8883]

Cool thanks, I will check that out tomorrow. I just went out and created a 2 point waypoint mission with a POI in the center and tried a few different things, none of which really got me what I wanted. The closest I came is with the video below. In this video the drone is facing in the direction of flight and then rotates half way though and flies backwards. Ideally the drone would fly sideways and tilt to keep things in the center.

So I went to record an example video so I could show you but the second mission I did with 3 waypoints didn’t work as well as this first one which I no longer have so I fiddled with it and what seems to work in all situations is to have 4 edit:5 waypoints. Starting waypoint, a waypoint just before the POI, a waypoint right after the POI and the end waypoint. Edit: and I have my first waypoint not part of the mission. This is because I want the drone all the way turned around to start

 

[D3D]

I will need to look at what you are saying more closely to see if it applies but I know for sure I don't want the rotation in the the way it is shown. Basically I want to recreate a camera slider behavior something similar to what you see at the 1:00 mark in this video:

. But facing straight down at the ground.

 

[brett8883]

I will need to look at what you are saying more closely to see if it applies but I know for sure I don't want the rotation in the the way it is shown. Basically I want to recreate a camera slider behavior something similar to what you see at the 1:00 mark in this video:

. But facing straight down at the ground.

Well you originally said you wanted the subject in the center of the frame the whole time? You couldn’t do that without turning because the gimbal can’t tilt backwards and none of the Mavic’s have a gimbal that can rotate freely 360 degrees. I don’t know of any drone that can tilt the gimbal much past -90 degrees.

If you want the poi to move through the frame instead of always being in the center this is how you’d do it.

This is how it would look.
waypoint 1 is just there to get things set no need to do any thing with it.

Waypoint 2:
point of interest 1
Focus POI
Leave very thing else as it is


waypoint 3 is the same
Focus POI
Point of interest 1
Focus Poi
Leave everything else as is but place it just above the POI and note the heading degrees and the gimbal pitch angle.


Heading in my example is 354 and gimbal pitch is -88

Waypoint 4 (the trick!)
Put it in line with waypoints two and three
Point of interest: none
Now put in the same heading degrees as waypoint 3
Gimbal pitch mode is “interpolate”
Put in the same gimbal angle as waypoint 3


So now instead of turning backwards to look at the POI it will just fly sideways with your POI moving out of the frame.

I’m sure there will be some tweaking involved to get the framing you want but that’s how you’d do it with waypoints.

You might even consider just using course lock and manually framing it how you want

 

[brett8883]

I think I see what you are looking for now and yea it is just an impossible angle straight down. You could do it off to the side but not straight down

 

[D3D]

So it can't be done with only the movement of the gimbal then. How about keeping the gimbal stationary but tilting the mavic so it points towards the POI and keeps it in the center at all times? Probably no way to do that either I suppose?

 

[Keule]

So it can't be done with only the movement of the gimbal then.

You need a drone with a gimbal able to pitch more than -90°.
An Inspire 2 is able to pitch its camera/gimbal in the range from -130° to+40°

If you need more then you must use an Industrial gimbal such as a Gremsy T7 with a pitch range of ±150° (but then you must have an aircraft capable of lifting the gimbal -> Matrice 600)

 

[brett8883]

So it can't be done with only the movement of the gimbal then. How about keeping the gimbal stationary but tilting the mavic so it points towards the POI and keeps it in the center at all times? Probably no way to do that either I suppose?

Even if you could control the aircraft attitude smoothly enough to make that work the gimbal will prevent that shot from happening since it won’t let the camera point down more than 90 degrees

 

[D3D]

Even if you could control the aircraft attitude smoothly enough to make that work the gimbal will prevent that shot from happening since it won’t let the camera point down more than 90 degrees

If you fly port or starboard direction and could control the pan of the camera you could do it

 

[Keule]

If you fly port or starboard direction and could control the pan of the camera you could do it

If you mean something like this?



No, it's because of the gimbal limitation is pitch, not pan.

You start at, let's say 100 ft with the aircraft pointing North, and the camera pointing to the East 090° and let's say -45° down and have the POI in the frame.

Then you fly a straight line by crabbing (Aileron only) a heading of 090°
You have to control the camera with pitch only to keep the center POI in the frame.

After you you reach the center POI (center picture), the camera is now tilted -90° down.
Continuing heading 090° (lower picture), the gimbal must now be tilted backward to keep the POI in the frame and that's impossible with the Mavic series.

And that is what @brett8883 was saying:
the gimbal will prevent that shot from happening since it won’t let the camera point down more than 90 degrees

 

[brett8883]

If you mean something like this?

View attachment 98785

No, it's because of the gimbal limitation is pitch, not pan.

You start at, let's say 100 ft with the aircraft pointing North, and the camera pointing to the East 090° and let's say -45° down and have the POI in the frame.

Then you fly a straight line by crabbing (Aileron only) a heading of 090°
You have to control the camera with pitch only to keep the center POI in the frame.

After you you reach the center POI (center picture), the camera is now tilted -90° down.
Continuing heading 090° (lower picture), the gimbal must now be tilted backward to keep the POI in the frame and that's impossible with the Mavic series.

And that is what @brett8883 was saying:
the gimbal will prevent that shot from happening since it won’t let the camera point down more than 90 degrees

I think he’s saying if the gimbal attitude is -90 degrees down from the aircraft and then you fly forward with an aircraft attitude of -40 degrees theoretically the gimbal could be pointed down -130 degrees below the horizon without tilting past the limit of -90 degrees from the aircraft but the issue is the software in the gimbal won’t allow that and will just adjust the gimbal up 40 degrees to maintain the -90 degree angle from the horizon and there’s no way to override that.

 

[Keule]

I think he’s saying if the gimbal attitude is -90 degrees down from the aircraft and then you fly forward with an aircraft attitude of -40 degrees theoretically the gimbal could be pointed down -130 degrees below the horizon without tilting past the limit of -90 degrees from the aircraft but the issue is the software in the gimbal won’t allow that and will just adjust the gimbal up 40 degrees to maintain the -90 degree angle from the horizon and there’s no way to override that.

Yep, but that's not gonna happen with Mavics - He needs an Inspire or an AC with a frame independent gimbal

 

[D3D]

That is great, really appreciate the graphics. So even though the movement shown in the video seems to demonstrate what I want you are saying the Mavic logic will rotate the camera once it reaches 90 degrees? I am new, totally prepared that the simple thing I want is impossible.

 

[Ty Pilot]

In your @D3D example above (post #6) , your video shows you flying towards and then over you, and sort of stopping and rotating 180 and then continuing on backwards on the original course. Even though this example wasn't necessarily 'fluid' from the camera's perspective, it is in my opinion, the only way you should shoot while flying directly over the top of and object as the frame never gets upside down.

In some of the posts the discussion of having the camera go beyond straight down to track the object as it flies past, it would begin to reveal an upside down image which; as you proceed much past the vertical (say 120 degrees) and begin to lift the camera towards the horizon to the rear, looks kind of awkward. My Typhoon H Plus will go about 110 degrees below horizontal and its already starting to look weird at that point.

If your example is what your after, I believe the Mavic is pretty well suited to do that type of shot manually. I've been practicing flight in a straight line where I rotate the aircraft 180 degrees without deviating from the flight path and found due to the Mavic'Pro2's soft rudder this is fairly easy to achieve. The process would be to approach the object while panning down to the vertical, perform the 180 and then get back on the gimbal to raise it as you fly over. Might take some practice but I think it could be done smoothly.