AC_AttitudeControl: rename thrust_heading_rotation_angles args

libraries/AC_AttitudeControl/AC_AttitudeControl.cpp

@@ -593,14 +593,14 @@ void AC_AttitudeControl::attitude_controller_run_quat()
 
 // thrust_heading_rotation_angles - calculates two ordered rotations to move the att_from_quat quaternion to the att_to_quat quaternion.
 // The first rotation corrects the thrust vector and the second rotation corrects the heading vector.
-void AC_AttitudeControl::thrust_heading_rotation_angles(Quaternion& att_to_quat, const Quaternion& att_from_quat, Vector3f& att_diff_angle, float& thrust_vec_dot)
+void AC_AttitudeControl::thrust_heading_rotation_angles(Quaternion& attitude_target_quat, const Quaternion& attitude_vehicle_quat, Vector3f& attitude_error_vector, float& thrust_error_angle)
 {
     Matrix3f att_to_rot_matrix; // rotation from the target body frame to the inertial frame.
-    att_to_quat.rotation_matrix(att_to_rot_matrix);
+    attitude_target_quat.rotation_matrix(att_to_rot_matrix);
     Vector3f att_to_thrust_vec = att_to_rot_matrix * Vector3f(0.0f, 0.0f, 1.0f);
 
     Matrix3f att_from_rot_matrix; // rotation from the current body frame to the inertial frame.
-    att_from_quat.rotation_matrix(att_from_rot_matrix);
+    attitude_vehicle_quat.rotation_matrix(att_from_rot_matrix);
     Vector3f att_from_thrust_vec = att_from_rot_matrix * Vector3f(0.0f, 0.0f, 1.0f);
 
     // the dot product is used to calculate the current lean angle for use of external functions
@@ -610,44 +610,44 @@ void AC_AttitudeControl::thrust_heading_rotation_angles(Quaternion& att_to_quat,
     Vector3f thrust_vec_cross = att_from_thrust_vec % att_to_thrust_vec;
 
     // the dot product is used to calculate the angle between the target and desired thrust vectors
-    thrust_vec_dot = acosf(constrain_float(att_from_thrust_vec * att_to_thrust_vec, -1.0f, 1.0f));
+    thrust_error_angle = acosf(constrain_float(att_from_thrust_vec * att_to_thrust_vec, -1.0f, 1.0f));
 
     // Normalize the thrust rotation vector
     float thrust_vector_length = thrust_vec_cross.length();
-    if (is_zero(thrust_vector_length) || is_zero(thrust_vec_dot)) {
+    if (is_zero(thrust_vector_length) || is_zero(thrust_error_angle)) {
         thrust_vec_cross = Vector3f(0, 0, 1);
-        thrust_vec_dot = 0.0f;
+        thrust_error_angle = 0.0f;
     } else {
         thrust_vec_cross /= thrust_vector_length;
     }
     Quaternion thrust_vec_correction_quat;
-    thrust_vec_correction_quat.from_axis_angle(thrust_vec_cross, thrust_vec_dot);
+    thrust_vec_correction_quat.from_axis_angle(thrust_vec_cross, thrust_error_angle);
 
     // Rotate thrust_vec_correction_quat to the att_from frame
-    thrust_vec_correction_quat = att_from_quat.inverse() * thrust_vec_correction_quat * att_from_quat;
+    thrust_vec_correction_quat = attitude_vehicle_quat.inverse() * thrust_vec_correction_quat * attitude_vehicle_quat;
 
     // calculate the remaining rotation required after thrust vector is rotated transformed to the att_from frame
-    Quaternion yaw_vec_correction_quat = thrust_vec_correction_quat.inverse() * att_from_quat.inverse() * att_to_quat;
+    Quaternion yaw_vec_correction_quat = thrust_vec_correction_quat.inverse() * attitude_vehicle_quat.inverse() * attitude_target_quat;
 
     // calculate the angle error in x and y.
     Vector3f rotation;
     thrust_vec_correction_quat.to_axis_angle(rotation);
-    att_diff_angle.x = rotation.x;
-    att_diff_angle.y = rotation.y;
+    attitude_error_vector.x = rotation.x;
+    attitude_error_vector.y = rotation.y;
 
     // calculate the angle error in z (x and y should be zero here).
     yaw_vec_correction_quat.to_axis_angle(rotation);
-    att_diff_angle.z = rotation.z;
+    attitude_error_vector.z = rotation.z;
 
     // Todo: Limit roll an pitch error based on output saturation and maximum error.
 
     // Limit Yaw Error based on maximum acceleration - Update to include output saturation and maximum error.
     // Currently the limit is based on the maximum acceleration using the linear part of the SQRT controller.
     // This should be updated to be based on an angle limit, saturation, or unlimited based on user defined parameters.
-    if (!is_zero(_p_angle_yaw.kP()) && fabsf(att_diff_angle.z) > AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP()) {
-        att_diff_angle.z = constrain_float(wrap_PI(att_diff_angle.z), -AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP(), AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP());
-        yaw_vec_correction_quat.from_axis_angle(Vector3f(0.0f, 0.0f, att_diff_angle.z));
-        att_to_quat = att_from_quat * thrust_vec_correction_quat * yaw_vec_correction_quat;
+    if (!is_zero(_p_angle_yaw.kP()) && fabsf(attitude_error_vector.z) > AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP()) {
+        attitude_error_vector.z = constrain_float(wrap_PI(attitude_error_vector.z), -AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP(), AC_ATTITUDE_ACCEL_Y_CONTROLLER_MAX_RADSS / _p_angle_yaw.kP());
+        yaw_vec_correction_quat.from_axis_angle(Vector3f(0.0f, 0.0f, attitude_error_vector.z));
+        attitude_target_quat = attitude_vehicle_quat * thrust_vec_correction_quat * yaw_vec_correction_quat;
     }
 }
 

libraries/AC_AttitudeControl/AC_AttitudeControl.h

@@ -287,7 +287,7 @@ public:
 
     // thrust_heading_rotation_angles - calculates two ordered rotations to move the att_from_quat quaternion to the att_to_quat quaternion.
     // The first rotation corrects the thrust vector and the second rotation corrects the heading vector.
-    void thrust_heading_rotation_angles(Quaternion& att_to_quat, const Quaternion& att_from_quat, Vector3f& att_diff_angle, float& thrust_vec_dot);
+    void thrust_heading_rotation_angles(Quaternion& attitude_target_quat, const Quaternion& attitude_vehicle_quat, Vector3f& attitude_error_vector, float& thrust_error_angle);
 
     // Calculates the body frame angular velocities to follow the target attitude
     void attitude_controller_run_quat();