DJI Go 4 app RTH computations?

[Lon Denard]

FC uses primarily distance to calculate battery necessary to LBRTH with a large margin. I believe you all are over thinking it.

 

[old man mavic]

FC uses primarily distance to calculate battery necessary to LBRTH with a large margin. I believe you all are over thinking it.

totally agree the drone has no idea of wind speed or direction, it knows where it took off from and how far it has traveled from that point, and when RTH is initiated because of the amount of battery left, it does its best to get back to the home point, it will initiate a RTH once it computes that it has only enough battery to make it back and land safely

 

[Lon Denard]

totally agree the drone has no idea of wind speed or direction, it knows where it took off from and how far it has traveled from that point, and when RTH is initiated because of the amount of battery left, it does its best to get back to the home point, it will initiate a RTH once it computes that it has only enough battery to make it back and land safely

Exactly!

 

[brett8883]

FC uses primarily distance to calculate battery necessary to LBRTH with a large margin. I believe you all are over thinking it.

I think height has a lot to do with it as well. Since LBRTH will auto-land at -only 3 m/s it will take 3x as much time to cover vertical distance as horizontal distance.

This won’t matter if you are only 50m up but it will if you are 500m+ up.

Testing in progress for this will update you guys on the findings but that’s my hypothesis.

 

[GadgetGuy]

The Smart

I think height has a lot to do with it as well. Since LBRTH will auto-land at -only 3 m/s it will take 3x as much time to cover vertical distance as horizontal distance.

This won’t matter if you are only 50m up but it will if you are 500m+ up.

Testing in progress for this will update you guys on the findings but that’s my hypothesis.

i can tell you from my experience that the displayed remaining flight time increases when you drop from high elevations relative to the the Home Point, as you descend back down a slope that you flew up. Elevation matters.

 

[Lon Denard]

I think height has a lot to do with it as well. Since LBRTH will auto-land at -only 3 m/s it will take 3x as much time to cover vertical distance as horizontal distance.

This won’t matter if you are only 50m up but it will if you are 500m+ up.

Testing in progress for this will update you guys on the findings but that’s my hypothesis.

Yes I want implying that elevation wasn't a pertinent metric...I was just trying to bring the conversation down from barometric pressure and wind speed. Hahaha! Besides, if you guys want to get picky, "distance" includes elevation.

 

[brett8883]

Yes I want implying that elevation wasn't a pertinent metric...I was just trying to bring the conversation down from barometric pressure and wind speed. Hahaha! Besides, if you guys want to get picky, "distance" includes elevation.

Ahhh you are right! ?

 

[GadgetGuy]

I believe RTH flies horizontally at the RTH altitude and then descends vertically at the Home Point, while an experienced pilot can bring it back far more efficiently on a straight glide path, along the hypotenuse of that triangle.

 

[Thomas B]

I believe RTH flies horizontally at the RTH altitude and then descends vertically at the Home Point, while an experienced pilot can bring it back far more efficiently on a straight glide path, along the hypotenuse of that triangle.

...if max speed is avoided.

 

[GadgetGuy]

...if max speed is avoided.

Assuming the same speed in both instances, the hypotenuse is a shorter way home than the the right angle sides of the triangle, and the accuracy of the remaining flight time becomes more accurate as you descend on a glide path, because you are descending during forward flight, rather than waiting for the slower descent rate until you are hovering over the home point.

 

[DanMan32]

Of course that assumes no obstacles along the hypotenuse. It's because of potential obstacles that RTH goes up, over, then down.

When I flew over the bay, I would descend as RTH was bringing it in, especially if I was rather high to start out, or in under this case.