Today, I flew my 7" quadcopter running ArduCopter version 4.5.7. When I increased the throttle, I noticed significant vibrations causing the quad to oscillate up and down. However, after reaching a certain altitude, it became stable, and I was able to successfully complete an autotune.
After that, I disarmed the quad and disconnected the battery. On the next flight, after reconnecting the battery and arming the quad, it exhibited uncontrollable vibrations and suddenly moved rapidly in one direction. In a panic, I disarmed it immediately.
If i see the log, it looks like the autotune is not properly saved. Also i can see the the loiter mode which is not recommended for autotune.
once check for the arducopter documentation for autotune.
Coming to error file i can see the input of pitch is given. Check from the RC channel whether it reversed or not in the Radio calibration tab in mission planner, also check the trims from the RC.
