Low Battery & RTH

[Nonprophet]

Wondering if the built-in low battery RTH activation takes into account the altitude ceiling you have set for RTH as well as the drone's distance to the RTH spot. In other words, if the drone is 1/4 mile from you and you have the RTH altitude set at 200' to avoid tall trees, does the Fly app/MM calculate how much power is needed to ascend to the RTH altitude, the power needed to return to and hover over the RTH spot, and then the power needed to power the drone while it descends and lands?

 

[CarstenB]

 

[Nonprophet]

View attachment 99790

Thanks, yes I read that in the manual, but what I'm wondering is if the timing of the low battery RTH feature/warning takes into account the distance to the home point and the time and power the MM will need to safely get to the home point without crashing.

 

[sar104]

Thanks, yes I read that in the manual, but what I'm wondering is if the timing of the low battery RTH feature/warning takes into account the distance to the home point and the time and power the MM will need to safely get to the home point without crashing.

It is calculated based just on distance to home point. The autoland level is calculated based on height above the home point.

 

[Nonprophet]

It is calculated based just on distance to home point. The autoland level is calculated based on height above the home point.

Thank you. So if I understand correctly, when the low battery "return to home" warning comes up and you don't cancel it, the software has calculated the distance to the home point, but not necessarily the altitude requirement that the pilot entered prior to taking off. So, in theory, if the pilot set a very high RTH altitude to avoid tall buildings (say 500') then when the RTH sequence is initiated the drone will ascend to the RTH altitude, and then start flying towards the home point. Descending from a high altitude can be slow, so, if the drone is positioned over the home point and descending from 500', but the battery goes dead at 100', then the drone crashes? Or, does the software calculate the time and power needed to get to the home point, descend, and land safely, and then autoland the drone short of the home point once the drone realizes that it's not going to have enough power to reach the home point and descend from the RTH altitude?

 

[sar104]

Thank you. So if I understand correctly, when the low battery "return to home" warning comes up and you don't cancel it, the software has calculated the distance to the home point, but not necessarily the altitude requirement that the pilot entered prior to taking off. So, in theory, if the pilot set a very high RTH altitude to avoid tall buildings (say 500') then when the RTH sequence is initiated the drone will ascend to the RTH altitude, and then start flying towards the home point. Descending from a high altitude can be slow, so, if the drone is positioned over the home point and descending from 500', but the battery goes dead at 100', then the drone crashes? Or, does the software calculate the time and power needed to get to the home point, descend, and land safely, and then autoland the drone short of the home point once the drone realizes that it's not going to have enough power to reach the home point and descend from the RTH altitude?

I think that the idea is that there is enough of a buffer in the calculation to take ascent and descent into account.