What is a HELIX

[Kaifect]

Where can I learn all this advanced Litchi stuff? I never did figure out how to view a mission in Google Earth.

 

[sar104]

Where can I learn all this advanced Litchi stuff? I never did figure out how to view a mission in Google Earth.

To view a mission in Google Earth, just select "MISSIONS > Export as KML 3D Path". Then you can just open the kml file in Google Earth. What other advanced Litchi stuff are you referring to?

 

[Kaifect]

A while back there was a tutorial about setting up a mission in Google Earth and then importing it to Litchi. The tutorial used an island near Miami, but I can't find anything about that anymore. It was called the Bridge I think.

 

[Kaifect]

Wow Thanks for the help. This is pretty interesting stuff .

 

[sar104]

A while back there was a tutorial about setting up a mission in Google Earth and then importing it to Litchi. The tutorial used an island near Miami, but I can't find anything about that anymore. It was called the Bridge I think.

I can't think of many reasons for wanting to construct a mission in Google Earth except for being able to define a track with fixed altitude AGL.You don't see ground elevation in Mission Hub until you actually create a waypoint, although once you get it onto a mobile device you can batch edit the waypoints to put them relative to ground.

It's clearly not difficult though, since you would simply construct a GE track and then go into the altitude dialog box and set the elevations, either absolute or relative to ground. But GE certainly won't make you anything fancy like a helix.

 

[sar104]

Wow Thanks for the help. This is pretty interesting stuff .

I automated the helix parameterization so it can be adjusted quite easily in terms of dimensions, location, altitude and orientation. An interesting, if rather niche exercise in linear transformations.

 

[Kaifect]

So how would I recreate that flight at a location near me?

 

[sar104]

So how would I recreate that flight at a location near me?

Not easily, since the helix is constructed in a custom user-defined function that I wrote in a numerical analysis program that you are unlikely to have access to. I'd probably have to construct it for you from appropriate parameters (pitch, number of turns, diameter, bearing, height, starting lat/long).

 

[Kaifect]

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[RNCotton]

I can see this, all ready to fly the mission after months of planning, designing the helix, testing the flight in open space ... and on the big day, the aircraft starts flying this beautiful helix, backing over and around the bridge, and smacks straight into the bridge supports that nobody remembered were there.

Cool concept ... would love to see it done. But not me.

 

[sar104]

I can see this, all ready to fly the mission after months of planning, designing the helix, testing the flight in open space ... and on the big day, the aircraft starts flying this beautiful helix, backing over and around the bridge, and smacks straight into the bridge supports that nobody remembered were there.

Cool concept ... would love to see it done. But not me.

Yes - that would be embarrassing. The pitch would definitely need to be chosen to avoid any inconvenient parts of the structure. Easy enough if everything is visible on Google Earth, otherwise it would require a survey or drawing.

 

[sar104]

This looks like a good practice run. Nothing to ambitious to begin with...

 

[RNCotton]

Looking at the bridge ... and the reflections in the water ... they are all driving upside down and defying gravity!

 

[sar104]

Looking at the bridge ... and the reflections in the water ... they are all driving upside down and defying gravity!

That's not a reflection - that's Google's imaging algorithm messing up and confusing what is above and below the water level. If you look at the underwater view in Google Earth you find that it assigns the roadway to the bed of the bay.

 

[The Editor]

In theory you could create a Litchi mission that describes such a flight path since the equation describing a helix is quite simple and then all one would have to do is transform it into lat/long/altitude with the bridge centerline as the axis. That's the easy part though - the important question would be whether it would need very dense waypoints or whether it would execute curved turns in the vertical, as well as horizontal plane.

Until the GPS HDOP/VDOP accuracy was compromised by the bridge structure and you lose your UAV.

 

[sar104]

Until the GPS HDOP/VDOP accuracy was compromised by the bridge structure and you lose your UAV.

Depending on the path and the bridge, that could happen. It's not an inevitability though - survey flights are conducted under bridges without loss of GPS. And in the case of the hypothetical flight shown above, I'd be more worried about magnetic interference from the structure.

 

[Andy Post]

Who did the stick about how many famous last words begin with “Hey...want to see something cool?” I would do multiple passes from varying angles n edit together. And for every drone I know of the props would be in frame for half that flight path.

 

[Rodger]

Thanks for the info. I agree looks difficult.

Beyond my skills. I would pass on that job.

 

[MrLaw10]

Sar104 you have spent some time flying and get it very well. I noticed that your amazing flight was in a very rural setting which I appreciated. Drones are here to stay with Amazon getting closer and closer to using them for delivery.

 

[sar104]

Sar104 you have spent some time flying and get it very well. I noticed that your amazing flight was in a very rural setting which I appreciated. Drones are here to stay with Amazon getting closer and closer to using them for delivery.

Thanks. Just to be clear - I haven't actually flown any of the flight paths depicted above - they are 3-D synthesized paths converted to KML descriptions and then imported into Litchi. They are ready to fly, but only flight plans.