Line data    Source code

       1             : /*
       2             :    This program is free software: you can redistribute it and/or modify
       3             :    it under the terms of the GNU General Public License as published by
       4             :    the Free Software Foundation, either version 3 of the License, or
       5             :    (at your option) any later version.
       6             : 
       7             :    This program is distributed in the hope that it will be useful,
       8             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :    GNU General Public License for more details.
      11             : 
      12             :    You should have received a copy of the GNU General Public License
      13             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             :  */
      15             : 
      16             : #include "AP_Proximity.h"
      17             : #include <AP_Common/AP_Common.h>
      18             : #include <AP_AHRS/AP_AHRS.h>
      19             : #include <AP_HAL/AP_HAL.h>
      20             : 
      21             : #if HAL_PROXIMITY_ENABLED
      22             : 
      23             : #define PROXIMITY_ALT_DETECT_TIMEOUT_MS 500 // alt readings should arrive within this much time
      24             : 
      25             : extern const AP_HAL::HAL& hal;
      26             : 
      27             : // set alt as read from downward facing rangefinder. Tilt is already adjusted for.
      28     1518828 : void AP_Proximity::set_rangefinder_alt(bool use, bool healthy, float alt_cm)
      29             : {
      30     1518828 :     _rangefinder_state.use = use;
      31     1518828 :     _rangefinder_state.healthy = healthy;
      32     1518828 :     _rangefinder_state.alt_cm = alt_cm;
      33     1518828 :     _rangefinder_state.last_downward_update_ms = AP_HAL::millis();
      34     1518828 : }
      35             : 
      36             : // get alt from rangefinder in meters
      37           0 : bool AP_Proximity::get_rangefinder_alt(float &alt_m) const
      38             : {
      39           0 :     if (!_rangefinder_state.use || !_rangefinder_state.healthy) {
      40             :         // range finder is not healthy
      41           0 :         return false;
      42             :     }
      43             : 
      44           0 :     const uint32_t dt = AP_HAL::millis() - _rangefinder_state.last_downward_update_ms;
      45           0 :     if (dt > PROXIMITY_ALT_DETECT_TIMEOUT_MS) {
      46           0 :         return false;
      47             :     }
      48             : 
      49             :     // readings are healthy
      50           0 :     alt_m = _rangefinder_state.alt_cm * 0.01f;
      51           0 :     return true;
      52             : }
      53             : 
      54             : // Check if Obstacle defined by body-frame yaw and pitch is near ground
      55      429304 : bool AP_Proximity::check_obstacle_near_ground(float pitch, float yaw, float distance) const
      56             : {
      57             : #if !APM_BUILD_TYPE(APM_BUILD_AP_Periph)
      58      429304 :     if (!_ign_gnd_enable) {
      59      429304 :         return false;
      60             :     }
      61           0 :     if (!hal.util->get_soft_armed()) {
      62             :         // don't run this feature while vehicle is disarmed, otherwise proximity data will not show up on GCS
      63           0 :         return false;
      64             :     }
      65           0 :     if ((pitch > 90.0f) || (pitch < -90.0f)) {
      66             :         // sanity check on pitch
      67           0 :         return false;
      68             :     }
      69             :     // Assume object is yaw and pitch bearing and distance meters away from the vehicle
      70           0 :     Vector3f object_3D;
      71           0 :     object_3D.offset_bearing(wrap_180(yaw), (pitch * -1.0f), distance);
      72           0 :     const Matrix3f body_to_ned = AP::ahrs().get_rotation_body_to_ned();
      73           0 :     const Vector3f rotated_object_3D = body_to_ned * object_3D;
      74             : 
      75           0 :     float alt = FLT_MAX;
      76           0 :     if (!get_rangefinder_alt(alt)) {
      77           0 :         return false;
      78             :     }
      79             : 
      80           0 :     if (rotated_object_3D.z > -0.5f) {
      81             :         // obstacle is at the most 0.5 meters above vehicle
      82           0 :         if ((alt - _alt_min_m) < rotated_object_3D.z) {
      83             :             // obstacle is near or below ground
      84           0 :             return true;
      85             :         }
      86             :     }
      87             : #endif
      88           0 :     return false;
      89             : }
      90             : 
      91             : 
      92             : #endif // HAL_PROXIMITY_ENABLED