I have built a heavy lift Octarotor with a payload capacity of 20kg.
The system is tuned fairly well and there were no major issues during flight.
I was performing auto missions to check the behavior in guided modes. The missions were going fairly well with 10 kg payload, but then I wanted to do an endurance test with full load of 20 kg.
The plan for the mission was to climb to 120m and then perform circles with LOITER_TURNS until the battery failsafe is triggered and RTL. However, once it reached the altitude and began the next leg of the mission, it began spinning uncontrollably and at multiple points during flight there was either one or two motors seemingly stopping mid flight. Any corrections did not seem to work and even multiple RTL commands did not stop the spinning, I even tried uploading a new mission mid flight to no avail. In the end when the system reached a lower altitude, we were able to regain control partially to switch to stabilize and do a hard landing.
One of the mistakes was this is the first time I have tried using LOITER_TURNS in a mission. The parameters I set seem alright, so I’m not sure what caused the spin. I assumed the spin was caused by a motor or ESC failure, but that wasn’t the case, all motor seems to be fine. But need further testing.
I am unable to deduce the cause for the uncontrolled spin. I need to know if it was a mistake in planning or the it was a component failure.
Any help you guys can provide will be much appreciated.
Thanks in advance.