Start-up: the gyros are being calibrated, keep the plane still
What ArduPilot says:
- Ground start with delay
- Ground start
- Skipping INS calibration
- Beginning INS calibration. Do not move plane
These lines come at every power-on. “Ground start” means the flight controller is starting on the ground and will set up its sensors. “Beginning INS calibration. Do not move plane”: for the next few seconds the gyros measure their zero and the barometer takes the ground pressure, so the plane must lie still (it need not be level). “Skipping INS calibration” appears instead when INS_GYR_CAL is 0 and the gyro offsets saved earlier are used. The alarming severity of the line is only there to make it visible.
What to do, most likely first
The plane was moved, or stood in the wind on its wheels, during those seconds.
FixReboot with the plane lying still. A horizon that tilts slowly on the ground right after start-up is the sign of a calibration spoiled by movement.
Parameters to look at
| Parameter | What it is |
|---|---|
INS_GYR_CAL | Gyro Calibration scheme |
The code that sends it
Ground start with delay
ArduPlane/system.cpp Plane::init_ardupilot() · Open in ArduPilot Plane-4.7.1
Ground start
ArduPlane/system.cpp Plane::init_ardupilot() · Open in ArduPilot Plane-4.7.1
Skipping INS calibration
ArduPlane/system.cpp Plane::startup_INS() · Open in ArduPilot Plane-4.7.1
Beginning INS calibration. Do not move plane
ArduPlane/system.cpp Plane::startup_INS() · Open in ArduPilot Plane-4.7.1