Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Litchi autonomous flight question?

Discussion in 'Pro/Adv Discussion' started by Mocho, Aug 15, 2016.

  1. Mocho

    Joined:
    Jun 16, 2016
    Messages:
    315
    Likes Received:
    64
    Location:
    Alberta, Canada
    I want to do a river run through a bunch of bends in the river, using Litchi waypoints. I did a shorter test run yesterday and it worked well, however I had a good R/C signal the whole time.

    If I set the missions finish action to "go home" will my bird fly at mission speed or default to DJI's return to home speed? I do anticipate a loss of R/C signal so I just want to ensure I understand what the bird should do after hitting the last way point and returning to home.

    TIA
     
  2. Mark The Droner

    Joined:
    Aug 26, 2015
    Messages:
    3,964
    Likes Received:
    1,158
    Location:
    Brookeville, MD, USA
    I don't have that option on my older version of Litchi. So I'll bump this for ya.

    I would imagine it would "go home" (or RTH) at RTH speed. But that's my guess. Let somebody else answer.

    You might consider just adding the last waypoint at home and taking the mystery out of the equation. Get some height first.
     
    cfd701 likes this.
  3. BigAl07

    BigAl07 Moderator
    Staff Member

    Joined:
    Jan 5, 2015
    Messages:
    2,362
    Likes Received:
    1,266
    Location:
    Western North Carolina
    I'm pretty sure the Litchi literature states that RTH uses the settings that are set within DJI Go. I don't have it with me to 100% confirm this but I'm really confident that it uses the DJI settings you program in whatever they are.
     
  4. Richard R

    Joined:
    Jan 27, 2016
    Messages:
    651
    Likes Received:
    239
    Location:
    Ohio
    And don't forget to check the RTH height. Default is 20 meters which may be too low, especially along a river where there may be trees. Remember, RTH is direct line back not a retracing of the route out. Give yourself plenty of margin.
     
  5. happydays

    Joined:
    Jul 5, 2013
    Messages:
    1,845
    Likes Received:
    655
    Location:
    Warrenpoint, Ireland
    I have used Litchi extensively to track a river and canal. One thing to make sure is that you don't follow the contours of the river exactly if it turns frequently - the end result will not be smooth. I did a lot like this and had to re-film it fairly often. What to do is make the course of the phantom smooth; the viewer won't mind if the course of the river moves around on the screen.

    For example, if there's a 'chicane' in the river, you might be tempted to fly the course, but the footage will be much better if you flew straight across. If the phantom follows the river, the heading changes too much for the video to be smooth.

    On RTH, I can't answer. Any time I used it I exited F Mode, flipping into P mode and then engaging RTH which it did at DJI's set speed.

    Why don't you go into a big field and do some testing? That's what I would do.

    Here's the clip - no need to watch it all, the first part shows what I mean about following the contours. Oh and film at a decent enough height. You might not see cables and the like. I flew at 50m and even then just about missed power lines crossing the canal - you can see that at 6.49. I was positioned just below them and had tested the height first! But I never saw them when plotting the route initially.

     
    BigAl07 likes this.
  6. matti

    Joined:
    Mar 15, 2016
    Messages:
    400
    Likes Received:
    62
    Good point.

    BTW in your example you speeded up the footage (at least the cars seemed faster than normal). I very often do the same by 2x-4x (sometimes slowing down the speed inside the scene to 0.5-1x if there are interesting objects) although mosts of my Litchi missions are already max ~57km/h. I try to keep my clips max 2minutes, depending on the content.

    With the speed-up it is even more important to have very smooth moves. Final Cut Pro can stabilize some jerkiness off but it also crops the footage more or less then.
     
  7. happydays

    Joined:
    Jul 5, 2013
    Messages:
    1,845
    Likes Received:
    655
    Location:
    Warrenpoint, Ireland

    It's 8x sped up. The route is about 32 UK miles so it would have been a hell of a long clip! For some of the jerky turns I slowed it back down again and also passing over all of the lock gates.
     
  8. Mocho

    Joined:
    Jun 16, 2016
    Messages:
    315
    Likes Received:
    64
    Location:
    Alberta, Canada
    Thanks for the input! Some good tips.

    The area of the river I want to video has several u bends in it with cliffs and or tall trees on either side so it's tricky to setup. And I don't have easy access to most of the river, which then runs through the city.
    I had setup a 24 point Litchi route and reviewed it a dozen times and had the map zoomed out before taking off. Started the motors and was ready to go. Looked down at the screen to see two more waypoints had been added taking me into the side of a cliff! I was SUPER cautious and this still happened so I won't be using Litchi waypoints until the Authour locks the screen so that can't happen. Had the map been zoomed in I would not have noticed the change and would have likely crashed into the side of a cliff.
    I plan to shoot some LARGE SCALE custom combining in a couple weeks and plan to use other features of Litchi. So I'm heading out to LARGE open fields today and will test the waypoint return speed there.
     
  9. Richard R

    Joined:
    Jan 27, 2016
    Messages:
    651
    Likes Received:
    239
    Location:
    Ohio
    Yes, you have to be careful. an inadvertent screen touch can add an unexpected waypoint! I've had to go back a few times and erase some errant waypoints. Fortunately, even zoomed in you should see a line indicating that the route continues on past your last intended waypoint a sure sign that you have an extra one!
     
  10. fastfed

    Joined:
    Jul 5, 2016
    Messages:
    544
    Likes Received:
    161
    just make the last waypoint back to your homepoint.
     
  11. Richard R

    Joined:
    Jan 27, 2016
    Messages:
    651
    Likes Received:
    239
    Location:
    Ohio
    If you do, make sure that the aircraft altitude is high enough to avoid any trees, cliffs, etc. before you head back. Going this route, i would add 2 waypoints, one right beside the last original last point. set the altitude at this new point to a safe altitude then go to a new last point near home. The Litchi manual doesn't say just when the aircraft changes altitude when 2 successive waypoints have different altitudes (i.e. does it change then move, move then change or change smoothly in route). If you RTH, it will change altitude first if RTH altitude is higher than the last waypoint or stay at the last waypoint altitude if that is higher than the RTH height.
     
  12. Richard R

    Joined:
    Jan 27, 2016
    Messages:
    651
    Likes Received:
    239
    Location:
    Ohio
    one other reminder that we all seem to mess up when first starting with Litchi. Waypoint actions will not be carried out if you have the route set to "Curved lines" instead of "Straight", because in Curved, the waypoints are never actually reached. So things like start and stop recording don't work in 'curved lines'. You would have to manually start and stop the camera. NO real problem, just something to be aware of. Not sure about altitude setting either. something to add to your experiments. Be interested in hearing how things work out for you. Good Luck!
     
  13. Mocho

    Joined:
    Jun 16, 2016
    Messages:
    315
    Likes Received:
    64
    Location:
    Alberta, Canada
    im fortunate to have retired early (56) from a high tech job, so I spend a LOT of time learning and am in no rush to "just" fly. I've designed Man Machine Interfaces for a billion $ Production facility so I am a bit of a stickler for poorly designed interfaces:)

    Yet Litchi waypoint feature still just about got me! There is no reason I can think of the author can't toggle edit/run screens, so I'll just wait until it gets fixed. Besides Litchi has other great features that be safely utilized and are better than DJI's app.
     
  14. Mocho

    Joined:
    Jun 16, 2016
    Messages:
    315
    Likes Received:
    64
    Location:
    Alberta, Canada
    A lot of good points being made! Thankfully I've considers most :)

    The other issue I was having, is with Litchi distance calculations. Keeps telling me my route is too long when it really isn't? In one case I flew the route manually and still had 50% battery. Yet Litchi wouldn't fly the same route? Also having issues with camera view not showing up at times, which works just fine in the DJI app?

    More testing in a safer spot is required :)