AP_Proximity: Make new Utils file for PRX utility functions

libraries/AP_Proximity/AP_Proximity.cpp

@@ -395,16 +395,6 @@ bool AP_Proximity::get_upward_distance(float &distance) const
     return get_upward_distance(primary_instance, distance);
 }
 
-// set alt as read from dowward facing rangefinder. Tilt is already adjusted for.
-void AP_Proximity::set_rangefinder_alt(bool use, bool healthy, float alt_cm)
-{
-    if (!valid_instance(primary_instance)) {
-        return;
-    }
-    // store alt at the backend
-    drivers[primary_instance]->set_rangefinder_alt(use, healthy, alt_cm);
-}
-
 #if HAL_LOGGING_ENABLED
 // Write proximity sensor distances
 void AP_Proximity::log()

libraries/AP_Proximity/AP_Proximity.h

@@ -155,6 +155,9 @@ public:
     // 3D boundary
     AP_Proximity_Boundary_3D boundary;
 
+    // Check if Obstacle defined by body-frame yaw and pitch is near ground
+    bool check_obstacle_near_ground(float pitch, float yaw, float distance) const;
+
 protected:
 
     // parameters for backends
@@ -174,6 +177,17 @@ private:
     AP_Int8 _raw_log_enable;                            // enable logging raw distances
     AP_Int8 _ign_gnd_enable;                           // true if land detection should be enabled
     AP_Float _filt_freq;                               // cutoff frequency for low pass filter
+
+    // get alt from rangefinder in meters. This reading is corrected for vehicle tilt
+    bool get_rangefinder_alt(float &alt_m) const;
+
+    struct RangeFinderState {
+        bool use;                          // true if enabled
+        bool healthy;                      // true if we can trust the altitude from the rangefinder
+        int16_t alt_cm;                    // tilt compensated altitude (in cm) from rangefinder
+        uint32_t last_downward_update_ms;  // last update ms
+    } _rangefinder_state;
+
 };
 
 namespace AP {

libraries/AP_Proximity/AP_Proximity_Backend.cpp

@@ -16,13 +16,9 @@
 #include "AP_Proximity_Backend.h"
 
 #if HAL_PROXIMITY_ENABLED
-#include <AP_Common/AP_Common.h>
 #include <AP_Common/Location.h>
 #include <AP_AHRS/AP_AHRS.h>
 #include <AC_Avoidance/AP_OADatabase.h>
-#include <AP_HAL/AP_HAL.h>
-
-extern const AP_HAL::HAL& hal;
 
 /*
   base class constructor. 
@@ -85,69 +81,7 @@ bool AP_Proximity_Backend::ignore_reading(float pitch, float yaw, float distance
     }
 
    // check if obstacle is near land
-   return check_obstacle_near_ground(pitch, yaw, distance_m);
+   return frontend.check_obstacle_near_ground(pitch, yaw, distance_m);
-}
-
-// store rangefinder values
-void AP_Proximity_Backend::set_rangefinder_alt(bool use, bool healthy, float alt_cm)
-{
-    _last_downward_update_ms = AP_HAL::millis();
-    _rangefinder_use = use;
-    _rangefinder_healthy = healthy;
-    _rangefinder_alt = alt_cm * 0.01f;
-}
-
-// get alt from rangefinder in meters
-bool AP_Proximity_Backend::get_rangefinder_alt(float &alt_m) const
-{
-    if (!_rangefinder_use || !_rangefinder_healthy) {
-        // range finder is not healthy
-        return false;
-    }
-
-    const uint32_t dt = AP_HAL::millis() - _last_downward_update_ms;
-    if (dt > PROXIMITY_ALT_DETECT_TIMEOUT_MS) {
-        return false;
-    }
-
-    // readings are healthy
-    alt_m = _rangefinder_alt;
-    return true;
-}
-
-// Check if Obstacle defined by body-frame yaw and pitch is near ground
-bool AP_Proximity_Backend::check_obstacle_near_ground(float pitch, float yaw, float distance) const
-{
-    if (!frontend._ign_gnd_enable) {
-        return false;
-    }
-    if (!hal.util->get_soft_armed()) {
-        // don't run this feature while vehicle is disarmed, otherwise proximity data will not show up on GCS
-        return false;
-    }
-    if ((pitch > 90.0f) || (pitch < -90.0f)) {
-        // sanity check on pitch
-        return false;
-    }
-    // Assume object is yaw and pitch bearing and distance meters away from the vehicle
-    Vector3f object_3D;
-    object_3D.offset_bearing(wrap_180(yaw), (pitch * -1.0f), distance);
-    const Matrix3f body_to_ned = AP::ahrs().get_rotation_body_to_ned();
-    const Vector3f rotated_object_3D = body_to_ned * object_3D;
-
-    float alt = FLT_MAX;
-    if (!get_rangefinder_alt(alt)) {
-        return false;
-    }
-
-    if (rotated_object_3D.z > -0.5f) {
-        // obstacle is at the most 0.5 meters above vehicle
-        if ((alt - PROXIMITY_GND_DETECT_THRESHOLD) < rotated_object_3D.z) {
-            // obstacle is near or below ground
-            return true;
-        }
-    }
-    return false;
 }
 
 // returns true if database is ready to be pushed to and all cached data is ready

libraries/AP_Proximity/AP_Proximity_Backend.h

@@ -19,9 +19,6 @@
 #if HAL_PROXIMITY_ENABLED
 #include <AP_Common/AP_Common.h>
 
-#define PROXIMITY_GND_DETECT_THRESHOLD 1.0f // set ground detection threshold to be 1 meters
-#define PROXIMITY_ALT_DETECT_TIMEOUT_MS 500 // alt readings should arrive within this much time
-
 class AP_Proximity_Backend
 {
 public:
@@ -45,9 +42,6 @@ public:
     // handle mavlink messages
     virtual void handle_msg(const mavlink_message_t &msg) {}
 
-    // store rangefinder values
-    void set_rangefinder_alt(bool use, bool healthy, float alt_cm);
-
 protected:
 
     // set status and update valid_count
@@ -64,12 +58,6 @@ protected:
     bool ignore_reading(float pitch, float yaw, float distance_m, bool check_for_ign_area = true) const;
     bool ignore_reading(float yaw, float distance_m, bool check_for_ign_area = true) const { return ignore_reading(0.0f, yaw, distance_m, check_for_ign_area); }
 
-    // get alt from rangefinder in meters. This reading is corrected for vehicle tilt
-    bool get_rangefinder_alt(float &alt_m) const;
-
-    // Check if Obstacle defined by body-frame yaw and pitch is near ground
-    bool check_obstacle_near_ground(float pitch, float yaw, float distance) const;
-
     // database helpers. All angles are in degrees
     static bool database_prepare_for_push(Vector3f &current_pos, Matrix3f &body_to_ned);
     // Note: "angle" refers to yaw (in body frame) towards the obstacle
@@ -79,12 +67,6 @@ protected:
     };
     static void database_push(float angle, float pitch, float distance, uint32_t timestamp_ms, const Vector3f &current_pos, const Matrix3f &body_to_ned);
 
-    // used for ground detection
-    uint32_t _last_downward_update_ms;
-    bool     _rangefinder_use;
-    bool     _rangefinder_healthy;
-    float    _rangefinder_alt;
-
     AP_Proximity &frontend;
     AP_Proximity::Proximity_State &state;   // reference to this instances state
     AP_Proximity_Params &params;            // parameters for this backend

libraries/AP_Proximity/AP_Proximity_Utils.cpp

@@ -0,0 +1,91 @@
+/*
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "AP_Proximity.h"
+#include <AP_Common/AP_Common.h>
+#include <AP_AHRS/AP_AHRS.h>
+#include <AP_HAL/AP_HAL.h>
+
+#if HAL_PROXIMITY_ENABLED
+
+#define PROXIMITY_GND_DETECT_THRESHOLD 1.0f // set ground detection threshold to be 1 meters
+#define PROXIMITY_ALT_DETECT_TIMEOUT_MS 500 // alt readings should arrive within this much time
+
+extern const AP_HAL::HAL& hal;
+
+// set alt as read from downward facing rangefinder. Tilt is already adjusted for.
+void AP_Proximity::set_rangefinder_alt(bool use, bool healthy, float alt_cm)
+{
+    _rangefinder_state.use = use;
+    _rangefinder_state.healthy = healthy;
+    _rangefinder_state.alt_cm = alt_cm;
+    _rangefinder_state.last_downward_update_ms = AP_HAL::millis();
+}
+
+// get alt from rangefinder in meters
+bool AP_Proximity::get_rangefinder_alt(float &alt_m) const
+{
+    if (!_rangefinder_state.use || !_rangefinder_state.healthy) {
+        // range finder is not healthy
+        return false;
+    }
+
+    const uint32_t dt = AP_HAL::millis() - _rangefinder_state.last_downward_update_ms;
+    if (dt > PROXIMITY_ALT_DETECT_TIMEOUT_MS) {
+        return false;
+    }
+
+    // readings are healthy
+    alt_m = _rangefinder_state.alt_cm * 0.01f;
+    return true;
+}
+
+// Check if Obstacle defined by body-frame yaw and pitch is near ground
+bool AP_Proximity::check_obstacle_near_ground(float pitch, float yaw, float distance) const
+{
+    if (!_ign_gnd_enable) {
+        return false;
+    }
+    if (!hal.util->get_soft_armed()) {
+        // don't run this feature while vehicle is disarmed, otherwise proximity data will not show up on GCS
+        return false;
+    }
+    if ((pitch > 90.0f) || (pitch < -90.0f)) {
+        // sanity check on pitch
+        return false;
+    }
+    // Assume object is yaw and pitch bearing and distance meters away from the vehicle
+    Vector3f object_3D;
+    object_3D.offset_bearing(wrap_180(yaw), (pitch * -1.0f), distance);
+    const Matrix3f body_to_ned = AP::ahrs().get_rotation_body_to_ned();
+    const Vector3f rotated_object_3D = body_to_ned * object_3D;
+
+    float alt = FLT_MAX;
+    if (!get_rangefinder_alt(alt)) {
+        return false;
+    }
+
+    if (rotated_object_3D.z > -0.5f) {
+        // obstacle is at the most 0.5 meters above vehicle
+        if ((alt - PROXIMITY_GND_DETECT_THRESHOLD) < rotated_object_3D.z) {
+            // obstacle is near or below ground
+            return true;
+        }
+    }
+    return false;
+}
+
+
+#endif // HAL_PROXIMITY_ENABLED