DataPilot & Terrain follow

[dsandson]

Just a quick question to see if anyone here has been using the new terrain follow feature? I eventually got it to run out on site 2 days ago. Site has substantial level differences so it was really needed.

The issue I had was around the terrain data. I had planned ahead and downloaded the maps and terrain for the area and transferred it from the desktop app to the controller by remote sync. Likewise for the flight plan as this was to be a double grid (DP only allows single grid with terrain follow so I added a second manually).

Unfortunately when I went to upload the plan to the drone out on site it complained it didnt have access to the terrain data on the server - of course, wifi was in use by the drone only! So I disconnected the drone wifi, powered up my phones hotspot, and tried redownloading a much larger area of mapping & terrain. Same problem when uploading to the drone.

After some swearing I finally found a workaround which was to connect to the hotspot & save the plan to a new file. This seemed to have forced a download of the correct terrain data, then I could connect the drone and upload the flight plan and off it went.

Have to say watching it change altitude on its own with some steep hilly terrain was rather dramatic, but it did a fantastic job, and with quite a stiff wid aloft!

Has anyone else had similar issues? I would consider some other method to make sure the controller can be online at this point as a back up, but I guess that could be tricky with android.

 

[arruntus]

It's happened to me too. I try to download the terrain directly into the ST16S, the maps in general. But sometimes it gets a little silly. The problem will arise when we are in places where we do not have telephone coverage and then we can not solve it if we have a problem.

 

[dsandson]

I suppose I was fortunate, as it was hilly I needed a high point to launch and maintain VLOS so had great cell coverage. I'd have been furious otherwise!!

 

[Wingman]

There is a feature on Android phones to share internet over USB or Bluetooth. I do not remember if there is Bluetooth on ST16S but you can definitely get internet over usb. Just plug a usb cable into your phone and st16s and in Android settings of your phone go USB Tethering and turn it on.

This way you do not need to create any wifi hotspot and you can still have your H520 still connected to your ST16s.

 

[Pawel_(PL)]

Hi there,

Hope you are all well in this time of pandemia!

I know that terrain follow option of the DataPilot has been already discussed but I am still not quite sure about some details.

When one ticks vehicle follows terrain box gets three fields to decide about:

• Tolerance (explained as: If adjacent terrain waypoints are within this tolerance they will be removed). Default set for 10 m.
• Max climb rate (The max. climb rate from one waypoint to another when adjusting for terrain. set to 0 for no max.) Default being 0 m/s
• Max descent rate (The max. descent rate from one waypoint to another when adjusting for terrain. set to 0 for no max.) Default - 0 m/s

I am not sure how to understand them. Especially the first one - Tolerance. From the practical point of view how to set this when say the hight from the lowest to the top point of a terrain is e.g. 10 m?

Has anyone flown terrain follow missions and could share her/his experience?

Appreciate,
Pawel

 

[dsandson]

Hi Pawel,

Just a quick one about the tolerance. So you put together a grid, and the first leg is from say point A to point B. Using the terrain below the software will introduce additional waypoints between A & B in order to follow the terrain.

The issue would be that terrain can be quite undulating or bumpy, so therefore tolerance will define how strictly the drone will try to follow the terrain. I think I have been happier with a 5m tolerance as a best compromise between the drone rising a fairly frequently versus keeping a fairly constant GSD.

I would normally fly between 50 to 65m altitude if that helps. The closer to the ground you fly then the more careful you will have to be. To be fair a prompt will come up I beleive to say a similar thing if you're plan below a min altitude.

 

[Pawel_(PL)]

Hi Pawel,

Just a quick one about the tolerance. So you put together a grid, and the first leg is from say point A to point B. Using the terrain below the software will introduce additional waypoints between A & B in order to follow the terrain.

The issue would be that terrain can be quite undulating or bumpy, so therefore tolerance will define how strictly the drone will try to follow the terrain. I think I have been happier with a 5m tolerance as a best compromise between the drone rising a fairly frequently versus keeping a fairly constant GSD.

I would normally fly between 50 to 65m altitude if that helps. The closer to the ground you fly then the more careful you will have to be. To be fair a prompt will come up I beleive to say a similar thing if you're plan below a min altitude.

Many thanks for your valuable advice.

Have performed some tests following your tips and will continue to do so. Furthermore I have also played with GoogleEarth visualisations of various Tolerance hights. I am getting the clue now.

How about climb/descent speeds? I think that there must be a correlation bamong flight speed and the other two. I was flying at 5 m/s and climb/descent set for 1 m/s and had a feeling that the latter ones were to slow to make h520 keep up to the mission plan in terms of getting to the right waypoints at the right time.
I will set them to 0 next time and see.



Thanks.
Pawel

 

[chascoadmin]

I would agree that even a 3m tolerance would be more desirable especially if you are in rolling hills, have any steep banks or drainage areas. The surface the system uses is a 10m resolution so mapping speed and PI's that already exist on the flight line could easily make you miss a couple of possibly crucial grade breaks. For climb and descent setting at 0 should follow the rules that you have in the base settings of DataPilot. I have said it before on different forums and Terrain Awareness (Following) threads that understanding the terrain before you plan is in your best interests. A good practice to keep in mind is to try to plan your flight path parallel with the contours of the land and you will greatly reduce the number of additional points needed to follow rise and fall.