Virtual Litchi Mission

[namirda]

1) Open your mission using the VLM Mission Hub Panel.
2) Then "Export as CSV" so that VLM performs the calculations and generates the smooth flightpath
3) Download the CSV file from Airdata into your watchfolder. VLM will the detect it, recognise it as an Airdata file and compare it with the planned flight path produced in 2). Some simple statistics are then produced in the Activity Log.

N

Namirda, It looks like this worked as you intended but I have a question as a result.
The csv file from airdata may be incomplete if your mission took the drone out of RC range for a moment or so. That would seem to affect the calculations in differences between the files.
Now that airdata is beta testing output csv files based on a user uploading the DJI .dat file, the new csv file contains the full flight data (since it came from the drone).
Would you consider being able to read that file instead? I have a few of them converted.
PS, I don't think Airdata widely advertised this yet but the notified a handful of users (myself included) because we had been pushing for this. It works exceedingly well!

(This started over a year ago when some of my flights had missing telemetry due to RC disconnects and I asked them about it as a feature request.)

The comparison between the Airdata csv file (which usually contains thousands of points) and the VLM Smoothed Path is performed as follows:

1) Starting at the beginning of the AirData file, I find the point which is nearest to the first VLM waypoint and record its distance from the waypoint as well as the difference in gimbal, heading and elevation.
2) I then progress through the Airdata file until I reach the Airdata point which is nearest to the second VLM waypoint and record the same differences as above.
3) Rinse and repeat until all VLM waypoints have been handled.
4) Calculate simple statistics.

It looks as if you have a very good match - your real flight had an average horizontal difference of only 0.48m with a standard deviation of 0.4m
and a vertical difference of 0.57m with a SD of almost nothing. Clearly I have some bug in my calculation of gimbal and heading values - or perhaps your drone was going out of range?

I originally wrote this little module as a diagnostic tool for myself to check that VLM was performing as it should - I never really thought it would have any value for users. Does it?

If you want to compare the real and planned missions you can easily import the kml from Airdata and overlay it on top of the VLM Smoothed flight path in GE for an immediate visual comparison. Did you do that?

N

 

[CAG]

"Please enable Elevation Featues in the Hub settings to use this feature." Where would that be? I don't find it.

Never mind. That was a really dumb question because I disable it before running the KML to see if that made a difference then forgot I did that. I thinkI have been working on this too long.

 

[namirda]

Namirda, It looks like this worked as you intended but I have a question as a result.
The csv file from airdata may be incomplete if your mission took the drone out of RC range for a moment or so. That would seem to affect the calculations in differences between the files.
Now that airdata is beta testing output csv files based on a user uploading the DJI .dat file, the new csv file contains the full flight data (since it came from the drone).
Would you consider being able to read that file instead? I have a few of them converted.
PS, I don't think Airdata widely advertised this yet but the notified a handful of users (myself included) because we had been pushing for this. It works exceedingly well!

(This started over a year ago when some of my flights had missing telemetry due to RC disconnects and I asked them about it as a feature request.)

Yes - I don't think reading a converted DAT file should be any problem. I'm just not convinced of the use case.

What do you do with the data?

N

 

[CAG]

I fixed it on my desk top. It took uninstalling GE and going through the Registry to remove everything related to GE. I then rebooted and reinstalled both GE and VLM. It works fine now. There was some entry somewhere that was messing things up.

 

[Prismatic]

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Virtual Litchi Mission is a free application (kudos to Namirda!) that lets you fully automate a drone flight. I planned this flight over the summer of 2018, and was able to fly it on Sept. 21, 2018.

About the Location:
The video was taken in the American Southwest, a region that includes Arizona, Utah, Nevada, most of New Mexico, parts of Colorado, and a big hunk of southern California. I call this special site "The Spirit of the Painted Desert". It makes me happy to know that, somewhere out there, a place like this actually exists. I hope that makes you happy, too.

About the Technology:
Y'all get this, right? VLM puts a robotic precision pilot in your Mavic, and it expertly follows a highly detailed flight plan. You can layer on control of the heading and gimbal, to make everything but the exposure automatic. I guess you could leave that on Auto, too, and just have a Daquiri while your bird does its thing.

About the Flight:
The wind was brutal. I debated even flying. But the light was exquisite. Part of my kit was an identical "lite" tour that gave me heading & gimbal control. I could pre-fly the mission with positive look-ahead to ensure safety along the entire path. That test flight proved out, despite the wind, so I launched the true mission. And held my breath for 10 long minutes. The video speaks for itself, and Bertie came home.

Disclaimer:
For the record, I have no affiliation or relationship of any kind, but particularly not of a financial kind, with User Namirda (all I have for a name) or probably anyone he-or-she knows. Nor do I have any such relationship with VC Technology Ltd, the makers of the Litchi family of products.

And I honestly only bought Litchi (it's cheap) to give VLM a shot. I was, and remain, stunned by what this software combo makes not just possible, but simple!

 

[namirda]

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Virtual Litchi Mission is a free application (kudos to Namirda!) that lets you fully automate a drone flight. I planned this flight over the summer of 2018, and was able to fly it on Sept. 21, 2018.

About the Location:
The video was taken in the American Southwest, a region that includes Arizona, Utah, Nevada, most of New Mexico, parts of Colorado, and a big hunk of southern California. I call this special site "The Spirit of the Painted Desert". It makes me happy to know that, somewhere out there, a place like this actually exists. I hope that makes you happy, too.

About the Technology:
Y'all get this, right? VLM puts a robotic precision pilot in your Mavic, and it expertly follows a highly detailed flight plan. You can layer on control of the heading and gimbal, to make everything but the exposure automatic. I guess you could leave that on Auto, too, and just have a Daquiri while your bird does its thing.

About the Flight:
The wind was brutal. I debated even flying. But the light was exquisite. Part of my kit was an identical "lite" tour that gave me heading & gimbal control. I could pre-fly the mission with positive look-ahead to ensure safety along the entire path. That test flight proved out, despite the wind, so I launched the true mission. And held my breath for 10 long minutes. The video speaks for itself, and Bertie came home.

Disclaimer:
For the record, I have no affiliation or relationship of any kind, but particularly not of a financial kind, with User Namirda (all I have for a name) or probably anyone he-or-she knows. Nor do I have any such relationship with VC Technology Ltd, the makers of the Litchi family of products.

And I honestly only bought Litchi (it's cheap) to give VLM a shot. I was, and remain, stunned by what this software combo makes not just possible, but simple!

@Prismatic Thank you for the kind words - always good to get positive feedback! Glad to hear VLM is appreciated.

And what an extraordinary place to fly Bertie - but you were very trusting of the technology taking your drone down into the ravine like that! You can't have been more than a few metres from the rock face. I'm glad Google and VLM did not let you down!

Over the last few months I have seen a number of videos posted by other VLM users showing the comparison between their virtual mission and the subsequent reality - but I have never before seen such an excellent match. Quite amazing.

N

 

[marklyn]

The comparison between the Airdata csv file (which usually contains thousands of points) and the VLM Smoothed Path is performed as follows:

1) Starting at the beginning of the AirData file, I find the point which is nearest to the first VLM waypoint and record its distance from the waypoint as well as the difference in gimbal, heading and elevation.
2) I then progress through the Airdata file until I reach the Airdata point which is nearest to the second VLM waypoint and record the same differences as above.
3) Rinse and repeat until all VLM waypoints have been handled.
4) Calculate simple statistics.

It looks as if you have a very good match - your real flight had an average horizontal difference of only 0.48m with a standard deviation of 0.4m
and a vertical difference of 0.57m with a SD of almost nothing. Clearly I have some bug in my calculation of gimbal and heading values - or perhaps your drone was going out of range?

I originally wrote this little module as a diagnostic tool for myself to check that VLM was performing as it should - I never really thought it would have any value for users. Does it?

If you want to compare the real and planned missions you can easily import the kml from Airdata and overlay it on top of the VLM Smoothed flight path in GE for an immediate visual comparison. Did you do that?

N

I have not done that because some/most of the missions I'm interested in comparing are ones where I lost RC contact so I was using the csv file generated by the Mavic dat file to see the real flight path. Up until now Airdata was only using the flight data from the DJI Go and Litchi app based on what was captured during a mission. This was flawed for me since it's not unusual for missions to lose RC contact for during the flight. Now Airdata is allowing the Mavic data file to be uploaded and processed, which is accurate since it comes from the Mavic itself (sorry, rambling). It's still in beta but looks really good. I'm trying to now work out in my mind how I can use the csv file that is generated from the Mavic and compare the flight to the csv file created by Litchi or DJI Go. Not sure if there is any major value for most folks but I can point to a large number of my past missions where the Airdata flight path is missing chunks of telemetry due to RC disconnects.
To your last point, the kml file in Airdata is generated from the flight data from the apps, I now wish they could also create one from the Mavic dat file for overlay comparison as you suggest. I shall ask them it they could do that

update** forget all of that. I just realized that when you upload a .dat file to Airdata they process it just like an upload from DJI Go or Litchi and a seperate list of downloadable files is created, including the KML... of course I can use that KML and the KML created by the app to compare in GE. I must still be asleep.

 

[Prismatic]

@Prismatic Thank you for the kind words - always good to get positive feedback! Glad to hear VLM is appreciated.

Thank you, in return, for VLM. An extraordinary piece of work.

And what an extraordinary place to fly Bertie - but you were very trusting of the technology taking your drone down into the ravine like that! You can't have been more than a few metres from the rock face. I'm glad Google and VLM did not let you down!

Once I was happy with the mission as planned, I duplicated it. In the duplicate, I set the mission Cruising Speed to zero (both in Litchi Mission Hub and the VLM Setup -- both matter!), set the mission Max Speed to maximum, and set the mission Heading Mode to Manual(UC). Then I set every WP to "Cruising Speed". Finally, I set the Gimbal Pitch on WP1 to -15°, and set the Gimbal Pitch for all other WPs to Disabled.

With a duplicate mission set up that way, you can push the Forward joystick to move along the path, stop and hover at will (even back up), look around, and basically assure yourself that this flight path is safe to fly fully automated : your bird isn't going to fly into the side of the ravine. And if you discover that it isn't safe in some section, you revise the duplicate mission and try again. When you're satisfied, you meticulously transfer any revised settings to the "main" mission, and you're good. My one nagging concern was that I'd easily lose some GPS satellites in the narrow ravine. A back-of-the-envelope calculation told me I wouldn't be losing much horizon, but I did lose a little. With high winds, that soft-spot in my plans was especially on my mind.

Over the last few months I have seen a number of videos posted by other VLM users showing the comparison between their virtual mission and the subsequent reality - but I have never before seen such an excellent match. Quite amazing.

I didn't expect that good a result, either! Once I'd (very carefully!) matched the first frame of each clip--and the last frame--I trimmed off the tag ends. One clip ended up two or three seconds longer, so I applied a .996x speed factor to match the run times. That's all it took.

Thanks again, so much, for putting this together. I wish the Mission Hub had a mission Heading Mode of "Direction of Travel". That would make setting up a duplicate test-flight even easier. Whatever it's doing on a spline curve, TNW does not give you the view "straight ahead". But that's what I want : the view straight ahead, even (especially) on a curving path.

 

[haiiiner]

VLM is a fantastic tool and like for many others here and all over the world very precious to me!

Greetings and thanks from Germany to namirda!

 

[marklyn]

Having a problem with a new mission. WP 1-4 are around POI, witch work fine but starting with waypoint 5 - 12, those waypoints are -25 through -35 yet at all of those waypoints the gimbal is showing to point down (-90) in GE. Can anyone take a look at this mission and tell me what I'm missing? I've got other similar missions that are completely fine yet this new one is giving me fits for no reason I can see.

 

[marklyn]

OK, now I'm really confused. I took the new mission I created and batch edited all of the waypoints and set all of them to -23 gimbal angle. Then I changed the heading for each waypoint to point in the direction of the flight. Now the gimbal angle seems to stay lined up ok, but the drone appears to be flying sideways to each (or even backwards) to some wp's, none of them so far are flying with the nose pointed in the same direction to the next wp.... It's not a matter of the drone 'turning' toward the next waypoint, it stays sideways through the next waypoint...Something is very strange here. Yet old missions fly exactly as they are laid out in VLM -> GE. This is my first new mission I've created in well over a month...


**update** I ran this same mission on another machine (laptop) and it runs correctly. Is there some setting in GE on my original machine that may be goofed up?

 

[crofter]

This ran once on my PC (great) but now, with new mission, it doesn't start automatically when new csv downloaded. If I start VLM manually, reset initial conditions, then use VLM to open the csv it says 'Sent to Google Earth'. I can see the path in GE but nothing happens. Am I missing something?

 

[namirda]

This ran once on my PC (great) but now, with new mission, it doesn't start automatically when new csv downloaded. If I start VLM manually, reset initial conditions, then use VLM to open the csv it says 'Sent to Google Earth'. I can see the path in GE but nothing happens. Am I missing something?

Hi,

Sorry - I don't really understand your problem. You need to run VLM as follows:

1) Start VLM and log in to your account on the Litchi Mission Hub
2) Load your mission and then export as csv - GE should start automatically.
3) You should be able to see your mission in GE and also a matching entry in 'Temporary Places'
4) Open your mission in 'Temporary Places' and double click on the entry called Virtual Mission'
5) That's all!

If this doesn't work then please show me a screenshot of what you see in Temporary Places in GE

Thanks

N

 

[crofter]

Hi,

Sorry - I don't really understand your problem. You need to run VLM as follows:

1) Start VLM and log in to your account on the Litchi Mission Hub
2) Load your mission and then export as csv - GE should start automatically.
3) You should be able to see your mission in GE and also a matching entry in 'Temporary Places'
4) Open your mission in 'Temporary Places' and double click on the entry called Virtual Mission'
5) That's all!

If this doesn't work then please show me a screenshot of what you see in Temporary Places in GE

Thanks

N

Thank you so much. Your software is amazing, like Litchi too. I am setting up a mapping mission in a very sensitive area and it helps that I can show the simulation video to all those concerned.
VLM doesn't at the moment obey the mission setting to RTH at last waypoint but just waits there. Is this normal? I tried to atttach the .csv but the uploader "The uploaded file does not have an allowed extension. "

 

[namirda]

Thank you so much. Your software is amazing, like Litchi too. I am setting up a mapping mission in a very sensitive area and it helps that I can show the simulation video to all those concerned.
VLM doesn't at the moment obey the mission setting to RTH at last waypoint but just waits there. Is this normal? I tried to atttach the .csv but the uploader "The uploaded file does not have an allowed extension. "

That's quite normal. VLM does not see the RTH command at the end of the mission because it is not present in the csv file which Litchi produces.

N

 

[Prismatic]

VLM does not see the RTH command at the end of the mission because it is not present in the csv file which Litchi produces.

So, Mission Hub has "Finish Action" options, but that setting isn't in the CSV. Oh well, it wouldn't help anyway; GE doesn't know from Home Points.

 

[OzoneVibe]

You know that feeling when you're about to ask a question that has a totally obvious answer that two days of playing with VLM has hidden from you? That's me!

a) Should the flight time in GE be the same(ish) as that shown at the top of Litchi Hub? Mine never are … GE is always a lot longer,
… and ...
b) Should the Cruise Speed be represented correctly in VLM (as it is in calculating that Litchi Hub flight time) because, with ALL WPs set to Cruise Speed I can still change the mission settings value, Mission Hub reflects that change, but almost no change is perceived in GE.

PS - this software is awesome! When those problems are sorted it will be a lot more awesomererer!

 

[radio_flyer]

Download latest version here :
Virtual Litchi Mission V2.3.0
---------------------------------------------------------------------------------------------------------------------

VLM Frequently Asked Questions



N

Hello namirda, I just discovered VLM and have 2 things to say: wow! and thanks!

I'm seeing a minor problem with the font scaling in VLM on my PC. Everything looks fine except the Settings dialogue box. The dialogue box itself it rather small and cannot be resized. The text for the messages runs into the right side of the dialogue box and is cut off. The text also covers some of the settings like the cruising speed so they cannot be seen or set. Also the font for "File Help Setup Exit" at the top left is microscopic on my display. That's not an issue but thought I'd mention it in case it is related.

I've attached a screen capture in case my description isn't clear.

Thanks again for an outstanding tool!

 

[namirda]

Hello namirda, I just discovered VLM and have 2 things to say: wow! and thanks!

I'm seeing a minor problem with the font scaling in VLM on my PC. Everything looks fine except the Settings dialogue box. The dialogue box itself it rather small and cannot be resized. The text for the messages runs into the right side of the dialogue box and is cut off. The text also covers some of the settings like the cruising speed so they cannot be seen or set. Also the font for "File Help Setup Exit" at the top left is microscopic on my display. That's not an issue but thought I'd mention it in case it is related.

I've attached a screen capture in case my description isn't clear.

Thanks again for an outstanding tool!

Hi,

Thanks for the feedback. I have not heard about screen problems like that before - what sort of screen resolution do you have?

I have only been able to test this on a screen of 1920*1080 and poorer - I don't have access to a fancy 4K screen!

Thanks

N

 

[radio_flyer]

Hi,

Thanks for the feedback. I have not heard about screen problems like that before - what sort of screen resolution do you have?

I have only been able to test this on a screen of 1920*1080 and poorer - I don't have access to a fancy 4K screen!

Thanks

N

Thanks for the response. The resolution of the screen captures I sent in the previous message was 3840 x 2160. I just loaded VLM on another computer (Microsoft Surface Pro 2) with resolution set to 1920 x 1080 and the VLM "Settings" dialog box looks the same as the first computer (see attachment). Maybe it's my old eyes!

Thanks again for a fantastic tool. I'm having lots of fun with it. If you could add a control to raise the outside temperature and calm the winds it would be perfect!