RTL mode malfunction in APM plane result in crash

hi, i dont know what happened all of a sudden my RTL mode is not functioning correctly and plunges straight down from 250meters. It happens when i manually trigger the RTL because my battery was running low. The RTL was functioning correctly before i update my mission planner. I kept on updating my firmware and mission planner to the latest version and the error still happens. Has anyone ever encounter this problem?

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  • thanks so much andrew and andreas,

    i see, maybe i missed interpreted the incident. it may be the the battery voltage. but i tried to test the RTL on the ground by carrying the plane away from the home position while giving it a little throttle so when the RTL kicks in i would know if the plane tries to go to home position, but when i change to RTL mode the motor stops. im afraid if this could happen in mid flight again. Can you check my parameter settings.

    go discover (21-09-2015).param

    • Developer

      Hi Ariff,

      That is caused by throttle suppression, which is a safety feature to prevent the motor starting and hurting someone if you temporarily lose RC control while on the ground and the failsafe kicks in.

      It will start the motor if you are moving at a significant speed or are more than a few meters off home altitude.

      Cheers, Tridge

  • Developer

    I think Andreas is right. The 4S battery is completely dead at the end. The plane was trying to climb to keep at the desired altitude and ended up stalling when the airspeed dropped to 7m/s.

    The FS_BATTERY_VOLTAGE was set to 12, which is far too low assuming you are using ordinary LiPo batteries. If your batteries are special low voltage batteries then let us know (there are some LiPo types that can keep going at that voltage, but they are quite unusual).

  • Ariff, Your planes stalled because there was no more power to fly. Your battery was below the 3V per cell mark. At this point the battery can not deliver any power.

  • incident occurs at tlog=98%. Is there any method to test the rtl function on the ground without being airborne, i dont want to crash them again

    2015-03-12 16-38-19.tlog

  • incident occurs at tlog=98%

  • Developer

    Hi Ariff, have you posted a log somewhere?

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