Copter: Allowing Terrain Following in Guided Mode

Uses frame type of MAVLINK_MSG_ID_SET_POSITION_TARGET_GLOBAL_INT message to decide the value of terrain_alt boolean.

ArduCopter/GCS_Mavlink.cpp

@@ -1085,6 +1085,7 @@ void GCS_MAVLINK_Copter::handleMessage(const mavlink_message_t &msg)
          */
 
         Vector3f pos_neu_cm;  // position (North, East, Up coordinates) in centimeters
+        bool terrain_alt = false;
 
         if(!pos_ignore) {
             // sanity check location
@@ -1102,6 +1103,7 @@ void GCS_MAVLINK_Copter::handleMessage(const mavlink_message_t &msg)
                 int32_t(packet.alt*100),
                 frame,
             };
+            terrain_alt = (loc.get_alt_frame() == Location::AltFrame::ABOVE_TERRAIN);
             if (!loc.get_vector_from_origin_NEU(pos_neu_cm)) {
                 break;
             }
@@ -1124,7 +1126,7 @@ void GCS_MAVLINK_Copter::handleMessage(const mavlink_message_t &msg)
         } else if (pos_ignore && !vel_ignore && acc_ignore) {
             copter.mode_guided.set_velocity(Vector3f(packet.vx * 100.0f, packet.vy * 100.0f, -packet.vz * 100.0f), !yaw_ignore, yaw_cd, !yaw_rate_ignore, yaw_rate_cds, yaw_relative);
         } else if (!pos_ignore && vel_ignore && acc_ignore) {
-            copter.mode_guided.set_destination(pos_neu_cm, !yaw_ignore, yaw_cd, !yaw_rate_ignore, yaw_rate_cds, yaw_relative);
+            copter.mode_guided.set_destination(pos_neu_cm, !yaw_ignore, yaw_cd, !yaw_rate_ignore, yaw_rate_cds, yaw_relative, terrain_alt);
         }
 
         break;

ArduCopter/mode.h

@@ -784,7 +784,7 @@ public:
     bool requires_terrain_failsafe() const override { return true; }
 
     void set_angle(const Quaternion &q, float climb_rate_cms, bool use_yaw_rate, float yaw_rate_rads);
-    bool set_destination(const Vector3f& destination, bool use_yaw = false, float yaw_cd = 0.0, bool use_yaw_rate = false, float yaw_rate_cds = 0.0, bool yaw_relative = false);
+    bool set_destination(const Vector3f& destination, bool use_yaw = false, float yaw_cd = 0.0, bool use_yaw_rate = false, float yaw_rate_cds = 0.0, bool yaw_relative = false, bool terrain_alt = false);
     bool set_destination(const Location& dest_loc, bool use_yaw = false, float yaw_cd = 0.0, bool use_yaw_rate = false, float yaw_rate_cds = 0.0, bool yaw_relative = false);
     bool get_wp(Location &loc) override;
     void set_velocity(const Vector3f& velocity, bool use_yaw = false, float yaw_cd = 0.0, bool use_yaw_rate = false, float yaw_rate_cds = 0.0, bool yaw_relative = false, bool log_request = true);

ArduCopter/mode_guided.cpp

@@ -176,7 +176,7 @@ void ModeGuided::angle_control_start()
 // guided_set_destination - sets guided mode's target destination
 // Returns true if the fence is enabled and guided waypoint is within the fence
 // else return false if the waypoint is outside the fence
-bool ModeGuided::set_destination(const Vector3f& destination, bool use_yaw, float yaw_cd, bool use_yaw_rate, float yaw_rate_cds, bool relative_yaw)
+bool ModeGuided::set_destination(const Vector3f& destination, bool use_yaw, float yaw_cd, bool use_yaw_rate, float yaw_rate_cds, bool relative_yaw, bool terrain_alt)
 {
     // ensure we are in position control mode
     if (guided_mode != Guided_WP) {
@@ -197,7 +197,7 @@ bool ModeGuided::set_destination(const Vector3f& destination, bool use_yaw, floa
     set_yaw_state(use_yaw, yaw_cd, use_yaw_rate, yaw_rate_cds, relative_yaw);
 
     // no need to check return status because terrain data is not used
-    wp_nav->set_wp_destination(destination, false);
+    wp_nav->set_wp_destination(destination, terrain_alt);
 
     // log target
     copter.Log_Write_GuidedTarget(guided_mode, destination, Vector3f());