Virtual Litchi Mission

[namirda]

Hi Namirda,

Thanks for your answer.
When I fly the virtual missions at a lower speed, or use fewer smoothing points, the abrupt speed drops become smaller. But they are still there. So maybe the reason is the introduced minimum flight time between WPs.

However, the simulation generated by VLM in GE has apparently changed from V 2.5.0 to V 2.7.0.
I was able to test this again because I'm still using V 2.5.0 on another computer.
In the attached example, the virtual flight almost stops at WP2 if it was generated with V 2.7.0. This is not the case if the virtual flight was generated with V2.5.0
Btw: My virtual missions are not faster than usual, around 28km/h. The number of smoothing points for each WP is at the default value of VLM (21)

Thank you for your effort in solving the problem.
Thalmann

The link to your example does not work for me - can you please check that you do not have the Private box ticked in the Mission Hub.

Thanks

 

[Thalmann]

The Private box was ticked in the Mission Hub - Sorry!
I have changed it. Now the link should work for you. Thanks.

 

[namirda]

Hi Namirda,

Thanks for your answer.
When I fly the virtual missions at a lower speed, or use fewer smoothing points, the abrupt speed drops become smaller. But they are still there. So maybe the reason is the introduced minimum flight time between WPs.

Hi Thalmann,

I have taken a look at your mission - here are a few comments:

1) The density of smoothed WPs around your WP2 is extreme - they are less than 1m apart which equates to less than 0.2 seconds at 28km/h. As I mentioned in a previous post, VLM 2.7.0 sets a minimum time between WPs of 1 second and so it is not surprising that the mission appears to stop around WP2.

2) There is a new version VLM2.7.1 now available which reduces the min time per WP to 0.05 seconds and so your mission should play properly if you install the update. However there are issues having WPs so close together (the issues relate to numerical rounding) and so it is better to avoid this if you can. VLM2.7.1 now adds a warning if the smoothed WPs are less than 1m apart

3) Suggestion - If your intention is to have a circular mission around the POI then maybe take a look at the helix option - it can generate a perfect circle if that is what you wish.

4) Finally, you may want to take a look at post 768 in this thread which is very relevant to missions like this which focus on a single POI. With some small changes, you can make this mission compatible with 'hotpoint' mode which means that in the 'real' mission, your drone will focus much more accurately on the POI. You may have noticed that VLM reports whether a mission is compatible with hotpoint mode or not.

Hope this helps.

N

 

[Thalmann]

Hi Namirda

Thank you so much for providing the new version of VLM That's it. It works very well!!

I've now reduced the number of smoothing points for each WP to a value of 15 - which is also quite enough for a smooth flight - and this avoid the warning mentioned. So, everything is fine. Thanks.

I've already tried the helix option - it's very nice! In my example, I used a different method to create a mathematically accurate ellipse. Anyway, it´s very convenient that VLM now has such functions.

I was following the discussion about the correct gimbal alignment to a POI during a mission at the time (post 768). I've been using VLM for a little longer and think I've understood the principle.
But, I am not sure, which conditions VLM must find to report "HotPoint Mode set to True". Does this mean that there is only 1 POI in a mission and all WPs have similar distances to this? This should prevent the heading ‘wander’, right?

Thalmann

 

[namirda]

Hi Namirda

Thank you so much for providing the new version of VLM That's it. It works very well!!

I've now reduced the number of smoothing points for each WP to a value of 15 - which is also quite enough for a smooth flight - and this avoid the warning mentioned. So, everything is fine. Thanks.

I've already tried the helix option - it's very nice! In my example, I used a different method to create a mathematically accurate ellipse. Anyway, it´s very convenient that VLM now has such functions.

I was following the discussion about the correct gimbal alignment to a POI during a mission at the time (post 768). I've been using VLM for a little longer and think I've understood the principle.
But, I am not sure, which conditions VLM must find to report "HotPoint Mode set to True". Does this mean that there is only 1 POI in a mission and all WPs have similar distances to this? This should prevent the heading ‘wander’, right?

Thalmann

DJI firmware has a feature called "Hotpoint Mode" in which the firmware in the drone will natively point the camera towards a single POI at all times. In this mode it is only required to send the coordinates of the POI to the drone and the DJI firmware does the rest. This results in excellent focus on the POI throughout the mission. Hotpoint Mode requires that there is only a single POI in the mission and that all WPs in the mission are using it.

Unfortunately the DJI firmware can only handle a single POI. Where a mission has multiple POI, the bearing and gimbal angle required to point the camera at the POI are calculated at each WP by the Litchi software and sent to the drone. This results in the camera pointing accurately towards the POI at each WP but less so in between because the angles are then interpolated.

VLM tries to mimic this as follows:

a) If the mission DOES NOT qualify for "Hotpoint Mode" then the Heading and Gimbal angles are calculated only at the point on the curve nearest to the WP and are interpolated at all points between - just like the Litchi software does.

b) If the mission DOES qualify for "Hotpoint Mode" then the Heading and Gimbal Angles are calculated at every Smoothed WP around the curve. This means the camera will point exactly at the POI at all smoothed WPs resulting in much less interpolation of the camera angles. This is as close as I can get to what the DJI firmware does.

If you want to reduce the effects of the interpolation further then it can help to add WPs to your mission such that all WPs which refer to a POI are about the same distance from it. Not always possible but it does help.

N

 

[Thalmann]

Thank you for the detailed and precise explanation. I will keep this in mind for my future missions.
With the additionally inserted WP for better point exactly at multiple POI during a mission - as described - the results in VLM are already excellent in my opinion. Thanks.

Thalmann

 

[HBRSNTD]

Hi Namirda,
first thank you for the new version of VLM2.7.1, I enjoy to use it. Today I came across an effect that irritates, starting at an angle 323° and choosing "outwards" as heading mode, the angle value continues to count above 360°, all other heading modes don't show this effect. I attach "helix setup form" and mission file, thanks for looking into.
Regards

Peter

 

[borodaagvali]

Hi!
I updated my Air 2S 2S drone to firmware v02.04.21.50 on the recommendation of DJI and Litchi.

DISAPPOINTED even more! How so, what's the deal? Why are you so not serious about your customers. Is it really impossible to correct mistakes in pulling the suspension normally? What did we pay so much money for? When purchasing your DJI product, we thought that you were a serious company. With all due respect, your product does not inspire trust and respect.


The route I flew and am flying for tests!
Everything works fine in the drone model Magic Air and Mavic Pro.
Well, in the Air 2S 2S drone, you can see for yourself what's going on.
And for some reason it seems that the old firmware 2040 was even better.

I don't know what to do, what to do!!!

 

[slup]

...DISAPPOINTED ...Why are you so not serious...Is it really impossible to correct mistakes...When purchasing your DJI product, we thought that you were a serious company. With all due respect, your product does not inspire trust and respect.

I'm not sure who you're addressing here ... this forum & the members commenting in this thread have no affiliates with either DJI or Litchi, & neither of these companies scans post here regarding comments about their products.

Take a look at post #1003, 1004 & 1005 for clues regarding your problem.

 

[namirda]

Hi Namirda,
first thank you for the new version of VLM2.7.1, I enjoy to use it. Today I came across an effect that irritates, starting at an angle 323° and choosing "outwards" as heading mode, the angle value continues to count above 360°, all other heading modes don't show this effect. I attach "helix setup form" and mission file, thanks for looking into.
Regards

Peter

Hi Peter,

Thank you for your feedback - indeed this is another bug!

Not only does a heading mode of "outward" produce headings above 360 but it causes some minor glitches in the virtual helix mission as well. Sorry.

I will put it on the list of fixes for the next release.

N

 

[borodaagvali]

Hi Namida!
There is great news from the developers of Litchi!
Now it is possible to make missions from more than 99 points of interest. This is a very good opportunity in Litchi. Now we will wait for you to fix the VLM, the ability to create or import a mission with points of interest greater than 99.

 

[namirda]

Hi Namida!
There is great news from the developers of Litchi!
Now it is possible to make missions from more than 99 points of interest. This is a very good opportunity in Litchi. Now we will wait for you to fix the VLM, the ability to create or import a mission with points of interest greater than 99.

VLM can already process missions with any number of waypoints and any number of POI.

However, missions created using the helix or grid options within VLM are currently limited to 99 waypoints simply because it seemed like a sensible limit to me and because that is the maximum number of waypoints which can be handled by Litchi without the use of virtual sticks.

I think there does need to be some sort of wp limit for automatic mission generation simply to avoid users creating massive missions which would blow out our use of the Google Elevation API.

What do you think the limit should be?

N

 

[clinkadink]

Great app, many thanks for providing this. The elevation panel is very helpful.

One suggestion if I may. When using the "Create mission around POI" feature, it would be great if it could default to having "Above Ground" checked.

Thanks again

 

[CallmeDash]

I second the motion to have "Above Ground" checked by default, I fell into the trap of not having it checked and wondered why it wasn't loading terrain elevation data

 

[DJ Wes]

Hi Namirda,

I have just downloaded and installed VLM version 2.7.1. Unfortunately, I have just discovered something that will prevent me from using the latest version. There appears to be a locking problem with any csv file that is imported.

Here are some details: I have written a number of external programs that generate Litchi missions whose output is a csv file. My typical workflow is to:

1. Externally generate a Litchi mission saved in a csv file
2. Import that csv file into VLM
3. Tweak and view in Google Earth
4. Go back to step 1, modify, and repeat

It seems that with the latest version of VLM, once imported, the csv file is locked. Even though I can successfully re-generate it, once I try to import it a second time into VLM, I get this error:


There is no other program running or locking the file at this time. VLM has exclusive access to this file. This does not happen in the Litchi Mission Hub. It also does not happen if I use a different csv file name each time. It did not happen in the previous versions of VLM.

Is there a way you can fix this?

 

[namirda]

Hi Namirda,

I have just downloaded and installed VLM version 2.7.1. Unfortunately, I have just discovered something that will prevent me from using the latest version. There appears to be a locking problem with any csv file that is imported.

Here are some details: I have written a number of external programs that generate Litchi missions whose output is a csv file. My typical workflow is to:

1. Externally generate a Litchi mission saved in a csv file
2. Import that csv file into VLM
3. Tweak and view in Google Earth
4. Go back to step 1, modify, and repeat

It seems that with the latest version of VLM, once imported, the csv file is locked. Even though I can successfully re-generate it, once I try to import it a second time into VLM, I get this error:

View attachment 148832
There is no other program running or locking the file at this time. VLM has exclusive access to this file. This does not happen in the Litchi Mission Hub. It also does not happen if I use a different csv file name each time. It did not happen in the previous versions of VLM.

Is there a way you can fix this?

Sorry for the late reply - for some reason the mavicpilots forum software does not always notify me when a new post is added here.

And I'm sorry but I cannot replicate this problem - have tried a few different csv files but have not experienced the problem you describe.

I would be very surprised if your problem is anything to do with VLM because the latest versions no longer open or read the csv file at all - the data is now taken directly from the Litchi DOM.

Anybody else having this problem?

N

 

[goixiz]

If i may request an option in the Waypoint edit setting screen = (waypoint auto heading ON) to allow users to change the heading of that particular point [currently grayed out]

 

[namirda]

If i may request an option in the Waypoint edit setting screen = (waypoint auto heading ON) to allow users to change the heading of that particular point [currently grayed out]

To change the heading of a particular waypoint you first need to set Heading Mode to "Custom(WD" in settings.

Also, note that these are Litchi settings and not directly related to VLM.

N

 

[Bussty]

Hello Namirda

Have always enjoyed using VLM and only recently discovered Version 7.3 so thank you!

I have just posted an issue I am having with Google Earth Pro here GEP Issue Link Mavic Pilots and I'm convinced this is a GEP thing but was just wondering if there were any plans (or is it even possible) to create a version of VLM that would work inside of Google Earth Studio and I'm thinking the issue I'm having may not happen in that software?

Thanks again and look forward to your thoughts.

Cheers

Bussty

 

[namirda]

Hello Namirda

Have always enjoyed using VLM and only recently discovered Version 7.3 so thank you!

..........

Hi Bussty,

Indeed I see the jump in your video at about the 6 minute mark but I cannot reproduce it using the 3 point mission which you posted. Neither the virtual mission nor the movie I made from it using the GE Movie Maker show any jumps - so not sure what is going on.

And as for GE Studio - well I have not yet looked into that at all - perhaps I should do so!

Sorry not to be more help

N