ardupilot/libraries/AP_Proximity/AP_Proximity_Utils.cpp

91 lines
2.9 KiB
C++

/*
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_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 - _alt_min) < rotated_object_3D.z) {
// obstacle is near or below ground
return true;
}
}
return false;
}
#endif // HAL_PROXIMITY_ENABLED