Flying an extreme Litchi waypoint program.

[cheddarman]

Just curious, being a newbie to Litchi..........

Where is the waypoint program information stored, in the AC or the RC, for example:

If I program a Litchi Waypoint course and one of the points is outside the control range of the RC, will the AC continue out to that point using just its GPS and then come back again or, when it got outside the RC range, would it just return to home?

 

[REL]

The Litchi Mission is uploaded to the AC before the mission is started. The drone will continue flying the mission on its own .....even if the RC to AC control is lost. You could actually turn off the controller mid-mission and the drone would complete the mission ....unless the mission sends it into an obstacle (because you programmed the mission incorrectly) ....or it runs out of battery power before it completes the mission (again because you programmed it incorrectly). I always program Mission Point #1 reasonably close to the takeoff point and let the mission finish back at Point #1. Once it returns to Point#1 , I just flip the switch to P (on my P3P) and land it manually.
For those far away missions ...... just make sure you have enough battery power to return home.
I LOVE Litchi Waypoint Missions !!

 

[Asmokely]

There is an option in the waypoint planning menu( left of screen) to specify what aircraft does in case of loss of contact. Either return home or continue mission. I have been very impressed with the reliablity of it with my p3s, but this morning it sent my freshly repaired p3a into the lake across the street from my house from 200’ up with no warning other than a brief gimbal overload message, followed by inversion, and acceleration towards the water. Such a bad day....

 

[cheddarman]

Well goodness me! One very positive and one disaster. Maybe Asmokely you didn't quite "repair" the P3A completely! Mine is a P3A and only ever had a gimbal repair by a DJI repair centre.

Please bear with an old man, learning:
Many thanks REL (I was a PO-REL in the navy ?). Most helpful post and one that I will trust. It's not actually a long flight, about 1.2miles away so shouldn't have any battery problems. The other thing is that the Beacon, where I plan to fly to, is about 850ft higher than my take-off location. Am I right in thinking that the drone will keep the height above ground that I set at take-off of could it fly into the hill?

 

[The Springs]

Id suggest you learn a bit more about how Litchi works before you try this .Plan some smaller missions first .You want the" trial and error "without the error ah .

 

[cheddarman]

Id suggest you learn a bit more about how Litchi works before you try this .Plan some smaller missions first .You want the" trial and error "without the error ah .

Um, not very helpful, so where would you suggest I look to learn? In my 80+ years I have found that the best way to learn is to try and learn from any mistakes along the way. I have flown several Waypoint missions around some large fields in the area with no problems encountered.
My query was that, even after a couple of years drone flying I'm not sure how it responds to a rising terrain. Does it maintain the set height or does it follow the terrain below it. The built in sensors will not be operational at 300ft so does the GPS maintain height as well as position.

 

[The Springs]

I looked at your planned mission on GE

 

[The Springs]

You can set the elevation at each waypoint yourself or select the above ground option which will set them for you but just remember that if you set your waypoints too far apart you may miss a rise in the ground since the phantom is flying from the height you set for one waypoint to the height you set for the next
The whole mission elevation wise is calculated from your take of point so always take off close to your first waymoint or at least at a place with a similar elevation I would place at least six waypoints on the way out and the same coming back and make it a slight loop rather than coming back on exactly the same path .Also remember to consider trees towers etc which can be 30m above the ground to start with.
Start high review the footage and plan the next one lower if all looks ok.
Just my thoughts

 

[cheddarman]

Thank you The Springs, most informative and reassuring!
Setting a couple of hundred feet above the Beacon will ensure adequate clearance there and, as suggested I'll also put several waypoints along the way, ensuring a gentle climb.
The way between me and the Beacon is all farm land, obviously some trees so my minimum height will be 300 feet on the first run.

 

[The Springs]

The other issues not often mentioned is that the Google Earth elevation which Litchi uses can be out by 11-12m in areas of constantly changing ground evevatin .This is why carefully reviewing the footage is important .After a while you get a feel for what real height above ground level is rather than what GE/Litchi says it is .
The other inconsistency that's not critical most of the time is that the position of the whole mission can sometimes shift laterally by 5-8m from day to day .

 

[Martin Healy]

Hi Cheddarman, greetings from Devon - I have a brother who was a PO in the Fleet Air Arm.

I don't mean to cork your juices but you should be aware that the CAA rule that you must maintain visual line of sight to your drone still applies to autonomous flights. This is generally accepted to be around 500M but I know that I struggle to pick out the drone in the sky much over 300M away.

Planning missions over undulating ground is tricky and not for the feint hearted. In the UK I have found that when planning the mission there is an error message indicating that accurate terrain height info is not available and we don't have LIDAR info on the Google map. You also need to heed the CAA rule that restricts the drone height to 400ft/120M above the ground that the drone is flying over at all points along its route.

Recently, I planned a Litchi mission (with permission) that started at the entrance to a country estate and then flew above the drive all the way to the mansion - around it and up and away from the house. I decided that rather than take unnecessary risks I would split this mission into 2 overlapping missions by saving the mission again with a different name and editing the 2 parts. Maybe this technique could be useful to you.

All the best and enjoy your flying. Regards, Martin

 

[Earls Court]

I found all my answers to using Litchi effectively when I subscribed to and enrolled in the “Phantom/Mavic Filmschool - Master autopilot with Litchi“.
I watched so many YouTube videos but found the course lectures and videos far more instructive. The mission of long distance and changing terrain is dealt with!
I enjoy Litchi because you can do so much with it in a safe flying way.

 

[REL]

Very good advice from The Springs, thank you for sharing! All of my missions so far are under 2 miles (round trip) over family owned mostly tree covered landscape that is relatively flat. I usually start with an initial flight at 300 feet just to be sure I clear everything. After reviewing the video from that flight I adjust downward for subsequent runs until I get what I want. In your case .... with such a great variation in altitude from one end to another, I like the Idea of starting with a shorter flight and slowly adding distance flight after flight, allowing you to gain experience and confidence as you go. It will be especially important to calculate the rise in terrain as the drone goes away from your take off point correctly, so take your time.

 

[John Locke]

I find the most useful tools in Litchi is the "elevation above first waypoint" tool in Misson Hub planning. Accuracy of this info is + or - 30' from what I have experienced, not counting buildings and towers, etc. This elevation information is enabled in the settings of the Mission Hub.

The example below gives the MSL elevation on top of a mountain, and how much higher this mountain top is versus the ground elevation of the first waypoint. If I flew this mission at 98' as shown, the craft would crash into the mountain if sensors didn't prevent it, because I flew a level flight of 98' altitude, instead of plotting an ascent to the proper 813' to keep a relatively similar altitude AGL. This is all fundamental stuff that you'll learn as you use Litchi. Great software!

Checking the "Above Ground" box helps with planning math, to keep adequate altitude above ground

 

[cheddarman]

Hey guys, amazing and much appreciated advice for an old git to get his head round. I'll be doing a lot more "back yard" missions before I let rip with the Beacon one. I can quite clearly see the beacon from where I would fly, it's not that far and I could therefore keep the drone in sight all the way.
Safe landings..........

 

[REL]

I find the most useful tools in Litchi is the "elevation above first waypoint" tool in Misson Hub planning. Accuracy of this info is + or - 30' from what I have experienced, not counting buildings and towers, etc. This elevation information is enabled in the settings of the Mission Hub.

The example below gives the MSL elevation on top of a mountain, and how much higher this mountain top is versus the ground elevation of the first waypoint. If I flew this mission at 98' as shown, the craft would crash into the mountain if sensors didn't prevent it, because I flew a level flight of 98' altitude, instead of plotting an ascent to the proper 813' to keep a relatively similar altitude AGL. This is all fundamental stuff that you'll learn as you use Litchi. Great software!

View attachment 119158

Checking the "Above Ground" box helps with planning math, to keep adequate altitude above ground


View attachment 119159

Thanks John for pointing out these subtle but important options that are built into Litchi to help us to have more fun and less crashes.

 

[Jeff A]

Don Wiley has prepared a really well done manual for Litchi program, as well as for the DJI Go & Go 4 programs. Click the link below.
Don Wiley's Download Page

 

[ArnoldLeVine]

Is there a map site where you can click and get the elevation at that point? It would help in preplanning Litchi missions using the Hub program for an area you are not familiar with.

 

[ArnoldLeVine]

I think I just figured out my own answer right within Litchi.

 

[Meta4]

Is there a map site where you can click and get the elevation at that point? It would help in preplanning Litchi missions using the Hub program for an area you are not familiar with.

It's called Google Earth