sensors: minor IMU bias saving updates

- sensors/vehicle_imu: reset learned cal on any calibration change
during parameter update
 - sensors/vehicle_imu: cleanup logic estimated bias -> calibration offset
saving
   - don't invalidate saved calibration (the point is to keep the last valid)
   - remove old debug code, etc
 - sensors/vehicle_imu: notify parameter changes if accel or gyro
calibration has changed
 - lib/sensor_calibration: add calibrated() and calibration_index()
getters, keep Accelerometer/Gyroscope/Magnetometer in sync

src/lib/sensor_calibration/Accelerometer.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -60,10 +60,6 @@ void Accelerometer::set_device_id(uint32_t device_id, bool external)
 		set_external(external);
 		_device_id = device_id;
 
-		if (_device_id != 0) {
-			_calibration_index = FindCalibrationIndex(SensorString(), _device_id);
-		}
-
 		ParametersUpdate();
 		SensorCorrectionsUpdate(true);
 	}
@@ -166,6 +162,10 @@ void Accelerometer::set_rotation(Rotation rotation)
 
 void Accelerometer::ParametersUpdate()
 {
+	if (_device_id != 0) {
+		_calibration_index = FindCalibrationIndex(SensorString(), _device_id);
+	}
+
 	if (_calibration_index >= 0) {
 
 		// CAL_ACCx_ROT

src/lib/sensor_calibration/Accelerometer.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -67,7 +67,9 @@ public:
 	void set_rotation(Rotation rotation);
 	void set_temperature(float temperature) { _temperature = temperature; };
 
+	bool calibrated() const { return (_device_id != 0) && (_calibration_index >= 0); }
 	uint8_t calibration_count() const { return _calibration_count; }
+	int8_t calibration_index() const { return _calibration_index; }
 	uint32_t device_id() const { return _device_id; }
 	bool enabled() const { return (_priority > 0); }
 	bool external() const { return _external; }

src/lib/sensor_calibration/Gyroscope.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -60,10 +60,6 @@ void Gyroscope::set_device_id(uint32_t device_id, bool external)
 		set_external(external);
 		_device_id = device_id;
 
-		if (_device_id != 0) {
-			_calibration_index = FindCalibrationIndex(SensorString(), _device_id);
-		}
-
 		ParametersUpdate();
 		SensorCorrectionsUpdate(true);
 	}
@@ -151,6 +147,10 @@ void Gyroscope::set_rotation(Rotation rotation)
 
 void Gyroscope::ParametersUpdate()
 {
+	if (_device_id != 0) {
+		_calibration_index = FindCalibrationIndex(SensorString(), _device_id);
+	}
+
 	if (_calibration_index >= 0) {
 
 		// CAL_GYROx_ROT

src/lib/sensor_calibration/Gyroscope.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -66,7 +66,9 @@ public:
 	void set_rotation(Rotation rotation);
 	void set_temperature(float temperature) { _temperature = temperature; };
 
+	bool calibrated() const { return (_device_id != 0) && (_calibration_index >= 0); }
 	uint8_t calibration_count() const { return _calibration_count; }
+	int8_t calibration_index() const { return _calibration_index; }
 	uint32_t device_id() const { return _device_id; }
 	bool enabled() const { return (_priority > 0); }
 	bool external() const { return _external; }

src/lib/sensor_calibration/Magnetometer.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020-2021 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

src/lib/sensor_calibration/Magnetometer.hpp

@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2020 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions