Our system is devided into 2 main systems:
- forward flight
- multi rotor flight
The forward flight system is a 30a/h 5S li-ion battery that also power all electronics.
The electronics are devided into 3 sections:
- flight critical
- mission critical
- non critical
The pixhawk gets his power from the power brick that goes from the battery to the forward flight motor AND from the servo rail. The servo rail gets power from a regulator connected directly to the battery. This would normally provide the redundancy for powering the pixhawk.
So in case of a battery failure, both the power from the power brick as well as the servo power would fail.
However, the nosecam video and video transmitter are also getting the power from the battery but through a different regulator (non critical equipment).
Since nosecam video kept on, this indicates it wasn’t a major battery failure as the video would also have stopped working.
In my opinion, a simultaneous failure of both the power brick as well as the servo rail power is very unlikely.
The servo power regulator is only supplying the pixhawk servo rail side. The servos get their power directly from yet another, dedicated regulator regulator (flight critical)
Since I took all precautions to make almost everything redundant and dividing it into the 3 sections, I have a hard time finding out what caused this crash.
I’m not monitoring the multirotor power system as the power requirements are very high and I go directly from battery to the esc’s from the multirotors. A power brick could not handle the maximum power requirements. These are over 120A peak.
It looks as if the pixhawk was somehow being reset, or got disarmt, or indeed had both power sources cut simultaneously.
I’m totally flabbergasted…