Understanding waypoint relationship betweer agl and asl

[j.r.r.]

I think that this option is only available on the website interface.

Thank you Sir!
In order to see this option one has to check 'Enable Elevation Feature' on global setting in Mission Hub.

 

[namirda]

Hi Bill,

Sorry about your drone - I'm also a bit puzzled why this crash happened.

This screenshot from VLM looks as if the mission should have been very safe


I think something else must have been going on here.

Do you have any logs of the flight? Did you upload it to AirData?

N

 

[sar104]

Hi Bill,

Sorry about your drone - I'm also a bit puzzled why this crash happened.

This screenshot from VLM looks as if the mission should have been very safe

View attachment 47149
I think something else must have been going on here.

Do you have any logs of the flight? Did you upload it to AirData?

N

Agreed - but I suspect the aircraft altitude limit prevented it from achieving those altitudes.

 

[WMartz]

Hi, I found the flight log in my tablet. Could you tell me how to post it here. Thanks
Bill Martz

 

[WMartz]

This is the picture of where the crash happened during my last mission. I am still trying to learn what file extensions this forum will accept so I can upload the flight log.
Thanks guys
Bill Martz

 

[sar104]

This is the picture of where the crash happened during my last mission. I am still trying to learn what file extensions this forum will accept so I can upload the flight log.
Thanks guys
Bill Martz

Use .txt.

 

[jag32266]

This might help, easy & cheap to make as I do have one-

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[WMartz]

Thanks sar104. I checked my litchi settings under maximum altitude and the field was empty. I never entered an altitude limit. I attached txt file of my flight log to this post.

 

[sar104]

Thanks sar104. I checked my litchi settings under maximum altitude and the field was empty. I never entered an altitude limit. I attached txt file of my flight log to this post.

Well it wasn't a maximum altitude problem, but there was something wrong with WP4. It followed the profile up to WP3 but then it did not climb appropriately for the WP4 altitude in the profile that you posted. The drop at the end was after collision.



That looks like a profile error.

 

[namirda]

Here is another picture of your fatal flight. It shows a similar story to that told by sar104.

Something was wrong with the programmed altitude of your WP4. The coordinates all look correct but something was definitely wrong with the altitude. Possibly an error with WP5 as well because the drone is showing no attempt to climb back to the correct altitude as it moves towards WP5

N

 

[namirda]

@WMartz

Bill - Did you ever reach more of an understanding of what might have gone wrong here?

I have run some checks on your mission and it looks to me as if the altitude used for WP4 was actually 100' rather than the 300' which I see published on Mission Hub and the altitude for WP5 was 50' rather than the published 300'

Is that possible? Were you perhaps modifying some WP parameters prior to take-off and did not save the modified mission to the Mission Hub?

Have you tried VLM? It's great for checking out your missions before you fly and will help avoid expensive accidents like this!!

N

 

[sar104]

@WMartz

Bill - Did you ever reach more of an understanding of what might have gone wrong here?

I have run some checks on your mission and it looks to me as if the altitude used for WP4 was actually 100' rather than the 300' which I see published on Mission Hub and the altitude for WP5 was 50' rather than the published 300'

Is that possible? Were you perhaps modifying some WP parameters prior to take-off and did not save the modified mission to the Mission Hub?

Have you tried VLM? It's great for checking out your missions before you fly and will help avoid expensive accidents like this!!

N

One other consideration - the Litchi version supporting Mavic 2 is still a pre-release beta, so I wonder if this problem could be related to running a non-supported version.

 

[WMartz]

I think you nailed it namirda. When I designed the original mission in mission hub I added the difference in msl between point 1 and points 4 and 5 to the agl which took the agl values to approx 650 feet at point 4 and approx 700 feet agl at point 5. when I tried to load the mission to the drone I recieved an error message several times. I was in a remote area at the time and thought that the agl I set for points 4 and 5 were to high and not legal so I reduced their agl to 300 feet like the rest of the points. I did not save the changes because I was in the field with no data connection and didn't know that I had to save the file before using it. I reopened the mission with the new agl levels and received no error messages and let the done take off. I guess I will not do that anymore.
Thanks guys for your help. If there is anything I could help you with just give me a shout.
Bill Martz