ObstacleAvoidance.cpp

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/**
 * @file ObstacleAvoidance.cpp
 */

#include "ObstacleAvoidance.hpp"

using namespace matrix;
using namespace time_literals;

/** Timeout in us for trajectory data to get considered invalid */
static constexpr uint64_t TRAJECTORY_STREAM_TIMEOUT_US = 500_ms;
/** If Flighttask fails, keep 0.5 seconds the current setpoint before going into failsafe land */
static constexpr uint64_t TIME_BEFORE_FAILSAFE = 500_ms;
static constexpr uint64_t Z_PROGRESS_TIMEOUT_US = 2_s;

ObstacleAvoidance::ObstacleAvoidance(ModuleParams *parent) :
    ModuleParams(parent)
{
    _desired_waypoint = empty_trajectory_waypoint;
    _failsafe_position.setNaN();
    _avoidance_point_not_valid_hysteresis.set_hysteresis_time_from(false, TIME_BEFORE_FAILSAFE);
    _no_progress_z_hysteresis.set_hysteresis_time_from(false, Z_PROGRESS_TIMEOUT_US);

}

void ObstacleAvoidance::injectAvoidanceSetpoints(Vector3f &pos_sp, Vector3f &vel_sp, float &yaw_sp,
        float &yaw_speed_sp)
{
    _sub_vehicle_status.update();
    _sub_vehicle_trajectory_waypoint.update();

    if (_sub_vehicle_status.get().nav_state == vehicle_status_s::NAVIGATION_STATE_AUTO_LOITER) {
        // if in failsafe nav_state LOITER, don't inject setpoints from avoidance system
        return;
    }

    const bool avoidance_data_timeout = hrt_elapsed_time((hrt_abstime *)&_sub_vehicle_trajectory_waypoint.get().timestamp)
                        > TRAJECTORY_STREAM_TIMEOUT_US;
    const bool avoidance_point_valid =
        _sub_vehicle_trajectory_waypoint.get().waypoints[vehicle_trajectory_waypoint_s::POINT_0].point_valid;

    _avoidance_point_not_valid_hysteresis.set_state_and_update(!avoidance_point_valid, hrt_absolute_time());

    if (avoidance_data_timeout || _avoidance_point_not_valid_hysteresis.get_state()) {
        PX4_WARN("Obstacle Avoidance system failed, loitering");
        _publishVehicleCmdDoLoiter();

        if (!PX4_ISFINITE(_failsafe_position(0)) || !PX4_ISFINITE(_failsafe_position(1))
            || !PX4_ISFINITE(_failsafe_position(2))) {
            // save vehicle position when entering failsafe
            _failsafe_position = _position;
        }

        pos_sp = _failsafe_position;
        vel_sp.setNaN();
        yaw_sp = NAN;
        yaw_speed_sp = NAN;
        return;

    } else {
        _failsafe_position.setNaN();
    }

    if (avoidance_point_valid) {
        pos_sp = Vector3f(_sub_vehicle_trajectory_waypoint.get().waypoints[vehicle_trajectory_waypoint_s::POINT_0].position);
        vel_sp = Vector3f(_sub_vehicle_trajectory_waypoint.get().waypoints[vehicle_trajectory_waypoint_s::POINT_0].velocity);

        if (!_ext_yaw_active) {
            // inject yaw setpoints only if weathervane isn't active
            yaw_sp =  _sub_vehicle_trajectory_waypoint.get().waypoints[vehicle_trajectory_waypoint_s::POINT_0].yaw;
            yaw_speed_sp = _sub_vehicle_trajectory_waypoint.get().waypoints[vehicle_trajectory_waypoint_s::POINT_0].yaw_speed;
        }
    }

}

void ObstacleAvoidance::updateAvoidanceDesiredWaypoints(const Vector3f &curr_wp, const float curr_yaw,
        const float curr_yawspeed, const Vector3f &next_wp, const float next_yaw, const float next_yawspeed,
        const bool ext_yaw_active, const int wp_type)
{
    _desired_waypoint.timestamp = hrt_absolute_time();
    _desired_waypoint.type = vehicle_trajectory_waypoint_s::MAV_TRAJECTORY_REPRESENTATION_WAYPOINTS;
    _curr_wp = curr_wp;
    _ext_yaw_active = ext_yaw_active;

    curr_wp.copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].position);
    Vector3f(NAN, NAN, NAN).copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].velocity);
    Vector3f(NAN, NAN, NAN).copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].acceleration);

    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].yaw = curr_yaw;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].yaw_speed = curr_yawspeed;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].point_valid = true;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_1].type = wp_type;

    next_wp.copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].position);
    Vector3f(NAN, NAN, NAN).copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].velocity);
    Vector3f(NAN, NAN, NAN).copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].acceleration);

    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].yaw = next_yaw;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].yaw_speed = next_yawspeed;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_2].point_valid = true;
}

void ObstacleAvoidance::updateAvoidanceDesiredSetpoints(const Vector3f &pos_sp, const Vector3f &vel_sp, const int type)
{
    pos_sp.copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_0].position);
    vel_sp.copyTo(_desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_0].velocity);
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_0].type = type;
    _desired_waypoint.waypoints[vehicle_trajectory_waypoint_s::POINT_0].point_valid = true;

    _pub_traj_wp_avoidance_desired.publish(_desired_waypoint);

    _desired_waypoint = empty_trajectory_waypoint;
}

void ObstacleAvoidance::checkAvoidanceProgress(const Vector3f &pos, const Vector3f &prev_wp,
        float target_acceptance_radius, const Vector2f &closest_pt)
{
    _position = pos;
    position_controller_status_s pos_control_status = {};
    pos_control_status.timestamp = hrt_absolute_time();

    // vector from previous triplet to current target
    Vector2f prev_to_target = Vector2f(_curr_wp - prev_wp);
    // vector from previous triplet to the vehicle projected position on the line previous-target triplet
    Vector2f prev_to_closest_pt = closest_pt - Vector2f(prev_wp);
    // fraction of the previous-tagerget line that has been flown
    const float prev_curr_travelled = prev_to_closest_pt.length() / prev_to_target.length();

    Vector2f pos_to_target = Vector2f(_curr_wp - _position);

    if (prev_curr_travelled > 1.0f) {
        // if the vehicle projected position on the line previous-target is past the target waypoint,
        // increase the target acceptance radius such that navigator will update the triplets
        pos_control_status.acceptance_radius = pos_to_target.length() + 0.5f;
    }

    const float pos_to_target_z = fabsf(_curr_wp(2) - _position(2));

    bool no_progress_z = (pos_to_target_z > _prev_pos_to_target_z);
    _no_progress_z_hysteresis.set_state_and_update(no_progress_z, hrt_absolute_time());

    if (pos_to_target.length() < target_acceptance_radius && pos_to_target_z > _param_nav_mc_alt_rad.get()
        && _no_progress_z_hysteresis.get_state()) {
        // vehicle above or below the target waypoint
        pos_control_status.altitude_acceptance = pos_to_target_z + 0.5f;
    }

    _prev_pos_to_target_z = pos_to_target_z;

    // do not check for waypoints yaw acceptance in navigator
    pos_control_status.yaw_acceptance = NAN;

    _pub_pos_control_status.publish(pos_control_status);
}

void ObstacleAvoidance::_publishVehicleCmdDoLoiter()
{
    vehicle_command_s command{};
    command.timestamp = hrt_absolute_time();
    command.command = vehicle_command_s::VEHICLE_CMD_DO_SET_MODE;
    command.param1 = (float)1; // base mode
    command.param3 = (float)0; // sub mode
    command.target_system = 1;
    command.target_component = 1;
    command.source_system = 1;
    command.source_component = 1;
    command.confirmation = false;
    command.from_external = false;
    command.param2 = (float)PX4_CUSTOM_MAIN_MODE_AUTO;
    command.param3 = (float)PX4_CUSTOM_SUB_MODE_AUTO_LOITER;

    // publish the vehicle command
    _pub_vehicle_command.publish(command);
}