Litchi Waypoint Mission - gimbal pitches up and down continously

dwallersv · Jun 14, 2017

Can't say why the gimbal was spazzing out. Sounds like a bug in the Mavic firmware.

Couldn't have been Litchi, though, you were disconnected.

georgem1956 · Jun 15, 2017

I set a POI then I use focus poi to get the angle then set the waypoint to interpolate to use that angle. Seems to work. Ok, have to ask, is that antenna you're flying near active? The obvious answer is signal interference from the antenna if it's broadcasting. That's what I'm having problems with. The signal that's interfering with my Mavic Pro is strong enough to distort the images sent back to my phone. It's a repeated and distinct pattern, very similar to the Histogram "distortions" which indicate over exposure.

dwallersv · Jun 15, 2017

@georgem1956, I understand what you're trying to do, but this is an incorrect usage of these settings.

For any of the gimbal tilt settings to work the Mavic must be connected to the RC. This is because the Mavic automation engine doesn't support a tilt angle parameter and automatic control of tilt angle transitions. Put more simply, the Mavic can not control the gimbal by itself.

So, for any gimbal tilt angle changes, the RC much be connected so the Litchi app can change gimbal tilt through transmitted commands.

Now, that said, assuming the RC is connected here's how the gimbal settings work:

Interpolate: Smoothly and linearly change tilt angle between two waypoints. Angle is user-defined in the waypoint settings.
Focus POI: Works exactly the same as interpolate, except tilt angle is automatically calculate by Litchi, and will be recalculated if waypoint location or altitude is changed, or POI location or altitude is changed. FPOI also automatically calculates and adjusts waypoint heading.

If you are truly trying to properly frame a POI from several waypoints, you should simply use FPOI. In flight, it's indistinguishable from Interpolate. However, if you set up with FPOI, then change the waypoint to interpolate, it's almost guaranteed you will adjust one of the waypoints or the POI location while continuing to plan/create the mission, the heading and gimbal angles will be off, and you'll think something's wrong with Litchi when you run the mission.

Gang, Litchi works fine. If you're getting weird results, it's almost 99% certain it's a misunderstanding in how various parameters behave, and how to set things up.

georgem1956 · Jun 15, 2017

Gotcha! Yeah, what I was trying to do still didn't work. I can't get the greens center frame even after multiple tries. The key here is that the RC is controlling the gimbal pitch and, not always, but more than infrequently I'm getting blasted with radio interference thus loosing RC control of the gimbal. Although.....the Litchi app did completely freeze one time and offered to report the problem while my drone is doing who know what...fortunately I was able to use the distance values on the RC itself to see that the drone was doing something, and it did record independently of the app. I assume the app uploads the mission from phone into memory space on the RC from whence it runs...next time I'm going with iOS...android is too flakey...

I'm going back to a simpler waypoint mission config with FPIO and hope my interference will subside. I do have antenna boosters for my RC. I wonder if that would help the RC/drone's tranmissions to penetrate the other interference?

georgem1956 · Jun 15, 2017

P.S. - I hit return to home after I believed the drone had finished it mission. It was hovering about 500ft away which is about where the mission ended. I thought I had set "return to first way point" at the end of the mission but guess not...

dwallersv · Jun 15, 2017

Can you locate yourself more centrally to the area covered by the waypoints? People also easily make the mistake that they have to start close to the first waypoint -- completely unnecessary if the mission is well within the duration of the battery. Then, start somewhere favorable to a good connection through the entire mission, and let the aircraft fly from the Home Point to the first waypoint. This can be quite a ways from the start of the mission, again so long as you have enough battery capacity for it.

Remember, all the aircraft is doing between you and the first waypoint is flying autonomously -- no different than what it's going to do through the mission.

Logger · Jun 15, 2017

dwallersv said:
... People also easily make the mistake that they have to start close to the first waypoint -- completely unnecessary if the mission is well within the duration of the battery. Then, start somewhere favorable to a good connection through the entire mission, and let the aircraft fly from the Home Point to the first waypoint. This can be quite a ways from the start of the mission, again so long as you have enough battery capacity for it.

Remember, all the aircraft is doing between you and the first waypoint is flying autonomously -- no different than what it's going to do through the mission.

There is a difference. Instead of flying your carefully planned vertical profile, it flies a line along a cone cone from ~ 30' above wherever you happen to take off today, to the height you programmed at waypoint 1, having no regard for obstacles in between. It is an easy mistake for you to make @dwallersv, but I would not say it is good practice.

Generally speaking, it is wise to place the first waypoint near to take off point at a safe height to clear known obstacles on the way to your observation area at subsequent waypoints. Hence the phantom film school banging on about always making sure your flight path between take off and WPT1 is clear before you launch. You can do this by adding a way point close by, unrelated to the observation segment of your route, as a means to ensure initial terrain clearance.

What the aircraft does between you and the first waypoint is take off and climb to ~ 30' then turn and fly straight to waypoint 1 and whatever height you have programmed there. If there is a 70' tree or even a 40' building nearby it will smack into it as it flies the leg climbing from 30' to whatever is programmed at a distant waypoint 1. Placing the first waypoint very close to your takeoff point at 100' would mitigate this risk. This would be analogous to an aircraft climbing to a safety height before departing an aerodrome.

Some exceptions would be it your are in the habit of taking off first, climbing to a safe height then loading the Litchi mission or at sites with guaranteed no obstacles. There is no downside I can see to having Waypoint 1 close the to take off point.

Logger · Jun 15, 2017

georgem1956 said:
I'm going back to a simpler waypoint mission config with FPIO and hope my interference will subside. I do have antenna boosters for my RC. I wonder if that would help the RC/drone's tranmissions to penetrate the other interference?

Have you tried the simple things like raising your mission height to see if you can maintain a connection. Say flying around the course at 250'. If that works you could use that to establish the path you wish to fly. If you carefully made sure your path bomb sights the greens flying directly over them at 250' (not beside them which requires gimbal angle change), could you not then do a subsequent lower mission at 80' with a fixed gimbal and guarantee the greens will be in frame? Just ensure the interpolate gimbal angle is set as constant between the WPTs where signal loss it likely, so there is no change to interpolate.
Otherwise your focus POI idea, should work so long as you can find a means to maintain a connection which may as @dwallersv mean moving yourself nearer to the action.

dwallersv · Jun 15, 2017

Logger said:
Some exceptions would be it your are in the habit of taking off first, climbing to a safe height then loading the Litchi mission or at sites with guaranteed no obstacles. There is no downside I can see to having Waypoint 1 close the to take off point.

Bingo.

I've never used automated takeoff in any of the apps. It takes more effort.

So, when I use Litchi, I always have a clear path to the first WP, since I've already ascended high enough before uploading the mission.

In my opinion, moving the launch point to achieve better connection is a far better approach than rejiggering the entire mission to move everything, which is a real PITA, and can mess up what you've spent a lot of time creating.

Otherwise, what's the alternative when you show up on site, run the 65 WP mission, and find that half of it doesn't work because it's disconnected? What do you do?

I examine the terrain, try to find a better spot to stay fully connected if at all possible, then do a mass-adjust of altitudes if there is a significant difference between my new launch point and the first WP.

If there's an easier way, please share.

dwallersv · Jun 15, 2017

@georgem1956, another alternative is to break the mission up in to several parts that each have a good connection from where you fly it. Then, put it all together in post.

I've had to do this a handful of times, and I've never had to do more than two segments, usually because a hill's in between them.

Logger · Jun 15, 2017

dwallersv said:
...
In my opinion, moving the launch point to achieve better connection is a far better approach than rejiggering the entire mission to move everything, which is a real PITA, and can mess up what you've spent a lot of time creating..

Yeah I dont know why you would want to rejig the entire mission. Sounds like a pain if you have had to do that.

Simply relocate to your new launch point to achieve the better connection and drag Waypoint1 to beside you. Set its height to something sensible. Hit Play that's it.

If your mission does not run as you wish due disconnects you really only have three choices. 1) relocate as you suggest in the hope of maintaining connection, 2) Raise the mission height in the hope of improving signal strength, or 3) redesign the mission to function in a workable manner disconnected.

There is a safety case for uploading your mission prior to launch, but horses for courses. Whatever works for you.

Logger · Jun 16, 2017

@georgem1956 I just stumbled across this

Done a year ago. So a phantom I guess. He does a half decent Golf course run a fair bit of which is without signal.

georgem1956 · Jun 16, 2017

@Logger, first, it wouldn't be practical to find a centralized point from which to run the missions. I plan to create a time lapse of the greens as they grow in over the summer. Since I still have to make a living I can zip over to the course, run the missions then back to work. Can't take the time to grab a cart and drive to and from this position. So that's out. Watching the above clip, at 1;54 to 1:57 the drone, for no apparent reason, swings clockwise then back. It appears to be on the long leg of the mission. This is what I am having problems with. For no apparent reason the drone will rotate away from the POI, which is not what I want. I don't really get why it does this.

What I want is to fly basically a simple path over the greens with POI's on each. I started with trying elaborate fly arounds of each but this was too much, took too much time and used too much battery power. Basically impractical. From waypoint 1 and through out the mission i have POI set to the next POI and expected the aircraft to stay pointed at that POI until released to the next POI. I've added additional waypoints along the paths to see if the aircraft would stay pointed properly. Below are the links to these missions if you're interested.

Clearly I don't quite get FPOI's. I thought that with the waypoint set for an FPOI the drone would point to it. The POI altitude is set to 3ft the gimbal angle auto-calculated. As the drone flies over however, it doesn't seem to point the where it's supposed to. I'll run these two missions to see if my tweaks helped, but they're not what I want. Rather than flying behind and around a given green, I'd like to fly up to it, capture the footage then go on to the next one.

I've poured through youtube looking for something more granular in explaining waypoints and POIs to see if I'm missing something. Even Lawrence's classes don't seem to show anything other than the obvious config for this. I think I understand how it works yet my videos don't do as expected. Notice I'm not pointing to the app, just my understanding of how to use it.

Mission Hub - Litchi
Mission Hub - Litchi

Let me know if you'd like to see the results of the above missions and I'll upload them.

dwallersv · Jun 16, 2017

George, are you having these POI problems with a good connection to the RC when those WPs are encountered? Or are you disconnected?

If disconnected, you will run into the gimbal tilt angle problem. Regardless of what the setting in the WP says for gimbal angle, if disconnected the gimbal will be pointing at whatever angle it was at when disconnected. This could be an angle you didn't even set, as the gimbal was moving between two set angles, from two WPs, when connection was lost.

Heading, OTOH, is executed by the automation engine disconnected. So Heading settings in WPs for POIs should work just fine disconnected (and it does for me).

I you're trying to focus on a POI with several WPs while disconnected, you can work around the gimbal issue by positioning the disconnected WPs so they all have the same gimbal tilt angle, then make sure a WP heading into the POI segment where you still have a connection has the gimbal set to your POI angle. Heading can be whatever you want (probably toward the POI too, but it doesn't matter).

georgem1956 · Jun 16, 2017

@dwallersv, I believe so. I've uploaded a video clip of the front nine with notes in the clip of what I expected vs what actually happened. below are the missions created in Mission Hub. My biggest concern has been focusing. I've noted on earlier runs that it was out of focus. With the mavic i guess this is a manual function. When I tap the screen, in waypoint mode, there is a significant delay before the camera will focus. Enough so that the object I selected to focus on is long gone. It occurs to me that I should pause the mission to set focus when I think it needs it. The clubhouse in the below clip illustrates (at the end). I've retimed this clip to speed it up so it won't be so long.

Mission Hub - Litchi
Mission Hub - Litchi

ok, not seeing how to upload a clip...?

georgem1956 · Jun 16, 2017

I'll push it up to youtube then put in the link.

georgem1956 · Jun 16, 2017

Here's the link....

Logger · Jun 16, 2017

I would say you are flying the corners and past the close by POIs too fast for the gimbal to keep up. Try reducing the speed to something much less less like 15-20 mph around the tight corners and as you pass POIs like 1. Envisage what the aircraft has to do to achieve your plan.

If you ultimately want to be able to do it reliably without connection you will need to lose all the POIs and flight plan over the Greens with the gimbal at a fixed angle in the no-com sections.

georgem1956 · Jun 19, 2017

Ah, forgot to mention...I retimed the clips, speeding them up by X2 to reduce the oversize for streaming and to make my points more quickly. Actually I went back to my Phantom4 and looks like it worked as expected. To be fair to the Mavic I made two alterations - 1) I really simplified both front and back nine missions and 2) I used range extenders on the remote to see if it would help. Well, yes and no, no meaning I lost contact with the drone several times but it was immediately regained.

I'm going to try the Mavic on the simplified plan tomorrow.

mickmacneil · Aug 13, 2017

georgem1956 said:
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

Hi George, I'm also having this same problem, gamble going up and down on a mission, when it should go to POI. Did you sus out a fix?