AC_PrecLand: use AHRS singleton, remove pointless initialisations

libraries/AC_PrecLand/AC_PrecLand.cpp

@@ -97,18 +97,10 @@ const AP_Param::GroupInfo AC_PrecLand::var_info[] = {
 // Note that the Vector/Matrix constructors already implicitly zero
 // their values.
 //
-AC_PrecLand::AC_PrecLand(const AP_AHRS_NavEKF& ahrs) :
-    _ahrs(ahrs),
-    _last_update_ms(0),
-    _target_acquired(false),
-    _last_backend_los_meas_ms(0),
-    _backend(nullptr)
+AC_PrecLand::AC_PrecLand()
 {
     // set parameters to defaults
     AP_Param::setup_object_defaults(this, var_info);
-
-    // other initialisation
-    _backend_state.healthy = false;
 }
 
 // init - perform any required initialisation of backends
@@ -158,6 +150,7 @@ void AC_PrecLand::update(float rangefinder_alt_cm, bool rangefinder_alt_valid)
 {
     // append current velocity and attitude correction into history buffer
     struct inertial_data_frame_s inertial_data_newest;
+    const AP_AHRS_NavEKF &_ahrs = AP::ahrs_navekf();
     _ahrs.getCorrectedDeltaVelocityNED(inertial_data_newest.correctedVehicleDeltaVelocityNED, inertial_data_newest.dt);
     inertial_data_newest.Tbn = _ahrs.get_rotation_body_to_ned();
     Vector3f curr_vel;
@@ -191,7 +184,7 @@ bool AC_PrecLand::get_target_position_cm(Vector2f& ret)
         return false;
     }
     Vector2f curr_pos;
-    if (!_ahrs.get_relative_position_NE_origin(curr_pos)) {
+    if (!AP::ahrs().get_relative_position_NE_origin(curr_pos)) {
         return false;
     }
     ret.x = (_target_pos_rel_out_NE.x + curr_pos.x) * 100.0f;   // m to cm
@@ -288,7 +281,7 @@ void AC_PrecLand::run_estimator(float rangefinder_alt_m, bool rangefinder_alt_va
 
             // Update if a new LOS measurement is available
             if (construct_pos_meas_using_rangefinder(rangefinder_alt_m, rangefinder_alt_valid)) {
-                float xy_pos_var = sq(_target_pos_rel_meas_NED.z*(0.01f + 0.01f*_ahrs.get_gyro().length()) + 0.02f);
+                float xy_pos_var = sq(_target_pos_rel_meas_NED.z*(0.01f + 0.01f*AP::ahrs().get_gyro().length()) + 0.02f);
                 if (!target_acquired()) {
                     // reset filter state
                     if (inertial_data_delayed.inertialNavVelocityValid) {
@@ -371,7 +364,7 @@ bool AC_PrecLand::construct_pos_meas_using_rangefinder(float rangefinder_alt_m,
             }
 
             // Compute camera position relative to IMU
-            Vector3f accel_body_offset = AP::ins().get_imu_pos_offset(_ahrs.get_primary_accel_index());
+            Vector3f accel_body_offset = AP::ins().get_imu_pos_offset(AP::ahrs().get_primary_accel_index());
             Vector3f cam_pos_ned = inertial_data_delayed.Tbn * (_cam_offset.get() - accel_body_offset);
 
             // Compute target position relative to IMU
@@ -396,6 +389,8 @@ void AC_PrecLand::run_output_prediction()
         _target_pos_rel_out_NE.y += _target_vel_rel_out_NE.y * inertial_data.dt;
     }
 
+    const AP_AHRS &_ahrs = AP::ahrs();
+
     const Matrix3f& Tbn = _inertial_history.peek(_inertial_history.size()-1).Tbn;
     Vector3f accel_body_offset = AP::ins().get_imu_pos_offset(_ahrs.get_primary_accel_index());
 

libraries/AC_PrecLand/AC_PrecLand.h

@@ -25,7 +25,7 @@ class AC_PrecLand
     friend class AC_PrecLand_SITL;
 
 public:
-    AC_PrecLand(const AP_AHRS_NavEKF& ahrs);
+    AC_PrecLand();
 
     /* Do not allow copies */
     AC_PrecLand(const AC_PrecLand &other) = delete;
@@ -114,9 +114,6 @@ private:
     // results are stored in_target_pos_rel_out_NE, _target_vel_rel_out_NE
     void run_output_prediction();
 
-    // references to inertial nav and ahrs libraries
-    const AP_AHRS_NavEKF&       _ahrs;
-
     // parameters
     AP_Int8                     _enabled;           // enabled/disabled and behaviour
     AP_Int8                     _type;              // precision landing sensor type

libraries/AC_PrecLand/AC_PrecLand_Companion.cpp

@@ -3,16 +3,6 @@
 
 extern const AP_HAL::HAL& hal;
 
-// Constructor
-AC_PrecLand_Companion::AC_PrecLand_Companion(const AC_PrecLand& frontend, AC_PrecLand::precland_state& state)
-    : AC_PrecLand_Backend(frontend, state),
-      _timestamp_us(0),
-      _distance_to_target(0.0f),
-      _have_los_meas(false),
-      _los_meas_time_ms(0)
-{
-}
-
 // perform any required initialisation of backend
 void AC_PrecLand_Companion::init()
 {

libraries/AC_PrecLand/AC_PrecLand_Companion.h

@@ -13,7 +13,7 @@ class AC_PrecLand_Companion : public AC_PrecLand_Backend
 {
 public:
     // Constructor
-    AC_PrecLand_Companion(const AC_PrecLand& frontend, AC_PrecLand::precland_state& state);
+    using AC_PrecLand_Backend::AC_PrecLand_Backend;
 
     // perform any required initialisation of backend
     void init() override;

libraries/AC_PrecLand/AC_PrecLand_IRLock.cpp

@@ -6,9 +6,7 @@ extern const AP_HAL::HAL& hal;
 // Constructor
 AC_PrecLand_IRLock::AC_PrecLand_IRLock(const AC_PrecLand& frontend, AC_PrecLand::precland_state& state)
     : AC_PrecLand_Backend(frontend, state),
-      irlock(),
-      _have_los_meas(false),
-      _los_meas_time_ms(0)
+      irlock()
 {
 }
 

libraries/AC_PrecLand/AC_PrecLand_SITL.cpp

@@ -7,12 +7,6 @@ extern const AP_HAL::HAL& hal;
 
 #include <stdio.h>
 
-// Constructor
-AC_PrecLand_SITL::AC_PrecLand_SITL(const AC_PrecLand& frontend, AC_PrecLand::precland_state& state)
-    : AC_PrecLand_Backend(frontend, state)
-{
-}
-
 // init - perform initialisation of this backend
 void AC_PrecLand_SITL::init()
 {
@@ -28,7 +22,7 @@ void AC_PrecLand_SITL::update()
 
     // get new sensor data; we always point home
     Vector3f home;
-    if (! _frontend._ahrs.get_relative_position_NED_home(home)) {
+    if (! AP::ahrs().get_relative_position_NED_home(home)) {
         _state.healthy = false;
         return;
     }
@@ -37,7 +31,7 @@ void AC_PrecLand_SITL::update()
     }
     _state.healthy = true;
 
-    const Matrix3f &body_to_ned = _frontend._ahrs.get_rotation_body_to_ned();
+    const Matrix3f &body_to_ned = AP::ahrs().get_rotation_body_to_ned();
 
     _los_meas_body =  body_to_ned.mul_transpose(-home);
     _los_meas_body /= _los_meas_body.length();

libraries/AC_PrecLand/AC_PrecLand_SITL.h

@@ -14,7 +14,7 @@ class AC_PrecLand_SITL : public AC_PrecLand_Backend
 public:
 
     // Constructor
-    AC_PrecLand_SITL(const AC_PrecLand& frontend, AC_PrecLand::precland_state& state);
+    using AC_PrecLand_Backend::AC_PrecLand_Backend;
 
     // perform any required initialisation of backend
     void init() override;