Welcome to PhantomPilots.com

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

Litchi question RTH tripped during mission due to calculated power.

Discussion in 'Pro/Adv Discussion' started by TK P3A, Apr 5, 2016.

  1. TK P3A

    Joined:
    Jan 24, 2016
    Messages:
    76
    Likes Received:
    16
    Searched all over and can't find an answer in manual or online so I thought I would ask you Litchi gurus.

    Using P3A with latest updates and Litchi on Android.

    During mission flights Litchi is triggering RTH and aborting the mission when the calculated RTH power reaches the available power (green disappears into red line).

    If I override the RTH with the "cancel" on screen or the RC RTH hard button and try to resume mission it attempts to return to the first mission point instead of continuing along where the mission left off.

    I have also tried pausing the mission and overriding with either button and it has the same effect.

    This is really only an issue on my long distance missions. When flying these distances manually with FPV I override the calculated RTH trigger and continue flying for another mile or so before I actually need to turn around based on actual RTH battery needed.

    If anyone has any ideas feel free advise.
     
  2. amckim2084

    Joined:
    Aug 9, 2015
    Messages:
    208
    Likes Received:
    54
    The same thing happened to me and it resulted in a crash because my waypoints went around big hills and it tried to go straight back to the homepoint. Battery was at 63%. I'm still trying to figure it out.
     
  3. Shammyh

    Joined:
    Apr 4, 2015
    Messages:
    325
    Likes Received:
    154
    Is this new behavior?

    I thought originally in waypoint mode it would fly until the battery died.

    If not, and especially if it's trying to return to the original waypoint, that's a pretty serious issue.
     
  4. amckim2084

    Joined:
    Aug 9, 2015
    Messages:
    208
    Likes Received:
    54
    I thought that too myself. If it has a failsafe to calculate distance and battery usage and it aborts the mission to return home, that could cause alot of crashes if the original waypoints went around obstacles. It happened to me and flew straight into a hill that was higher than my failsafe altitude.
     
  5. FrequentFlyer

    Joined:
    Feb 14, 2016
    Messages:
    145
    Likes Received:
    32
    Location:
    Riverside,Ca
    In Waypoint mode there is a setting that when it finishes a mission you have the option to reverse. That sounds like the best option in that situation. You could RTH if your RTH altitude was high enough. [​IMG]


    Sent from my iPhone using PhantomPilots mobile app
     
    #5 FrequentFlyer, May 19, 2016
    Last edited: May 19, 2016
  6. FrequentFlyer

    Joined:
    Feb 14, 2016
    Messages:
    145
    Likes Received:
    32
    Location:
    Riverside,Ca
    I think you need to disable SMART RTH in DJI GO (make sure your connected to the aircraft. )


    Sent from my iPhone using PhantomPilots mobile app
     
    bkushner likes this.
  7. amckim2084

    Joined:
    Aug 9, 2015
    Messages:
    208
    Likes Received:
    54
    My situation was a little different. I attempted a 5 mile one way trip. Since you can't set finish actions or even a last waypoint beyond 2000m (1.2 miles), I had to make waypoints back home as well. 75 waypoints total but the 5 mile mark was 40. I drove to 40 after takeoff and waited to take control again. It came into range at 30 and after 31, it requested to go home, I hit cancel, and it ignored it and still aborted. Battery was 63% at that point. If it did that whole calculation thing, would that be the reason it RTH on me? Also, seeing your other comment, would disabling Smart RTH prevent that mission abort?
     
  8. FrequentFlyer

    Joined:
    Feb 14, 2016
    Messages:
    145
    Likes Received:
    32
    Location:
    Riverside,Ca
    I believe it does. I am going to test it out today. Someone else probably has a definitive answer. I've heard that the missions continue after a lost connection.


    Sent from my iPhone using PhantomPilots mobile app
     
  9. amckim2084

    Joined:
    Aug 9, 2015
    Messages:
    208
    Likes Received:
    54
    It definitely continued the mission when I drove off and lost signal. I've done full shorter missions with lost signal and everything was fine. This was the furthest I ever attempted with a mission. I didn't even know what Smart RTH was but it makes sense now. The Smart battery makes an RTH decision based on power needed to go home. Man, almost a year of flying and I'm still learning things lol.
     
    FrequentFlyer likes this.
  10. Not A Speck Of Cereal

    Joined:
    Mar 8, 2016
    Messages:
    405
    Likes Received:
    145
    What I'm finding out is that it's not so smart as it doesn't take head and tail winds into consideration. I had a smart RTH the other day that came back and when it landed, I still had more than 50% of the battery left.
     
  11. amckim2084

    Joined:
    Aug 9, 2015
    Messages:
    208
    Likes Received:
    54
    Yeah, I have heard about that. I've never actually had a Smart RTH before except recently when it ended up crashing into trees. I either RTH it myself or I have had signal lost RTH with just normal GPS flying. Waypoint mission times aren't always accurate either. I had an 18 min mission complete in 14 mins.
     
  12. StevenATL5

    Joined:
    Jan 17, 2016
    Messages:
    9
    Likes Received:
    4
    No matter what mode your flying in always set your RTH altitude above all surrounding obstacles.
    Not to be rude but thats a Phantom pilots RULE # 1 where there are absolutely no exceptions
     
  13. StevenATL5

    Joined:
    Jan 17, 2016
    Messages:
    9
    Likes Received:
    4
    I see the same thing happen with my P4. Back in the early P3 days mine would return with 15 to 20 % every time and that was awesome I was amazed by that.
     
  14. Alex Baxter

    Joined:
    May 14, 2016
    Messages:
    264
    Likes Received:
    99
    Location:
    County Kilkenny, Ireland
    I have a 14 minute Litchi mission that only takes 10 minutes, but I've got curved waypoints, so to speak, so it just cruises past waypoints, rather than pausing, there are about 30 waypoints in the mission. (I'm attempting a time lapse over the local woods, to cover all four seasons in the year, starting in the winter, and completing the next winter, got 30 missions flown in the last 3 months)