AP_InertialSensor: removed INS_CALSENSFRAME

it is no longer needed as we have shifted the accel cal indexes

libraries/AP_InertialSensor/AP_InertialSensor.cpp

@@ -45,6 +45,7 @@ const AP_Param::GroupInfo AP_InertialSensor::var_info[] PROGMEM = {
       ACC2OFFS : 6
       ACC3SCAL : 8
       ACC3OFFS : 9
+      CALSENSFRAME : 11
      */
 
     // @Param: GYROFFS_X
@@ -116,13 +117,6 @@ const AP_Param::GroupInfo AP_InertialSensor::var_info[] PROGMEM = {
     AP_GROUPINFO("GYR3OFFS",   10, AP_InertialSensor, _gyro_offset[2],   0),
 #endif
 
-    // @Param: INS_CALSENSFRAME
-    // @DisplayName: Calibration is in sensor frame
-    // @Description: This is an internal parameter that records whether accelerometer calibration was done in sensor frame. It is used to detect an old accel calibration which was done in body frame. This parameter is automatically set during accelerometer calibration and should not be changed by the user.
-    // @Values: 0:BoardFrame,1:SensorFrame
-    // @User: Advanced
-    AP_GROUPINFO("CALSENSFRAME", 11, AP_InertialSensor, _cal_sensor_frame, 0),
-
     // @Param: ACCSCAL_X
     // @DisplayName: Accelerometer scaling of X axis
     // @Description: Accelerometer scaling of X axis.  Calculated during acceleration calibration routine
@@ -548,10 +542,6 @@ bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract* interact
 
         _board_orientation = saved_orientation;
 
-        // now set and save the INS_CALSENSFRAME parameter so we know
-        // the calibration was done in sensor frame
-        _cal_sensor_frame.set_and_save(1);
-
         return true;
     }
 

libraries/AP_InertialSensor/AP_InertialSensor.h

@@ -268,9 +268,6 @@ private:
     // filtering frequency (0 means default)
     AP_Int8     _mpu6000_filter;
 
-    // was the accel cal done in sensor frame?
-    AP_Int8    _cal_sensor_frame;
-
     // board orientation from AHRS
     enum Rotation _board_orientation;
 

libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp

@@ -12,14 +12,10 @@ AP_InertialSensor_Backend::AP_InertialSensor_Backend(AP_InertialSensor &imu) :
 void AP_InertialSensor_Backend::_rotate_and_correct_accel(uint8_t instance, Vector3f &accel) 
 {
     /*
-      we rotate before or after offset and scaling based on the
-      INS_CALSENSFRAME parameter. This allows us to use older
-      calibrations, while making all new calibrations operate in
-      sensor frame, and thus be independent of AHRS_ORIENTATION
+      accel calibration is always done in sensor frame with this
+      version of the code. That means we apply the rotation after the
+      offsets and scaling.
      */
-    if (_imu._cal_sensor_frame == 0) {
-        accel.rotate(_imu._board_orientation);
-    }
 
     // apply scaling
     const Vector3f &accel_scale = _imu._accel_scale[instance].get();
@@ -30,9 +26,8 @@ void AP_InertialSensor_Backend::_rotate_and_correct_accel(uint8_t instance, Vect
     // apply offsets
     accel -= _imu._accel_offset[instance];
 
-    if (_imu._cal_sensor_frame != 0) {
-        accel.rotate(_imu._board_orientation);
-    }
+    // rotate to body frame
+    accel.rotate(_imu._board_orientation);
 }
 
 void AP_InertialSensor_Backend::_rotate_and_correct_gyro(uint8_t instance, Vector3f &gyro)