Files
PX4-Autopilot/src/modules/simulation/gz_plugins/airspeed/AirSpeed.cpp
Jaeyoung Lim 5df20b8e9b Add custom gz airspeed plugin and add wind effects (#26018)
* Add px4 custom airspeed sensor

* Format fix
2025-12-01 08:56:40 -08:00

138 lines
5.1 KiB
C++

/****************************************************************************
*
* Copyright (c) 2025 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#include "AirSpeed.hpp"
#include <gz/plugin/Register.hh>
#include <gz/msgs/air_speed.pb.h>
using namespace px4;
// Sign function taken from https://stackoverflow.com/a/4609795/8548472
template <typename T> int sign(T val)
{
return (T(0) < val) - (val < T(0));
}
// Register the plugin
GZ_ADD_PLUGIN(
AirSpeed,
gz::sim::System,
AirSpeed::ISystemPreUpdate,
AirSpeed::ISystemConfigure
)
void AirSpeed::Configure(const gz::sim::Entity &entity,
const std::shared_ptr<const sdf::Element> &sdf,
gz::sim::EntityComponentManager &ecm,
gz::sim::EventManager &eventMgr)
{
_entity = entity;
_model = gz::sim::Model(entity);
const std::string link_name = sdf->Get<std::string>("link_name");
_link_entity = _model.LinkByName(ecm, link_name);
std::string model_name = _model.Name(ecm);
if (!_link_entity) {
throw std::runtime_error("Airspeed::Configure: Link \"" + link_name + "\" was not found. "
"Please ensure that your model contains the corresponding link.");
}
_link = gz::sim::Link(_link_entity);
// Needed to report linear & angular velocity
_link.EnableVelocityChecks(ecm, true);
_world_entity = gz::sim::worldEntity(ecm);
_world = gz::sim::World(_world_entity);
std::string world_name = _world.Name(ecm).value_or("default");
std::string airspeed_topic = "/world/" + world_name + "/model/" + model_name +
"/link/airspeed_link/sensor/air_speed/air_speed";
_pub = _node.Advertise<gz::msgs::AirSpeed>(airspeed_topic);
std::string wind_topic = "/world/" + world_name + "/wind_info";
_node.Subscribe(wind_topic, &AirSpeed::windCallback, this);
///TODO: Read sdf for altitude home position
}
void AirSpeed::PreUpdate(const gz::sim::UpdateInfo &_info,
gz::sim::EntityComponentManager &_ecm)
{
const auto optional_pose = _link.WorldPose(_ecm);
if (optional_pose.has_value()) {
_vehicle_position = optional_pose.value().Pos();
_vehicle_attitude = optional_pose.value().Rot();
} else {
gzerr << "Unable to get pose" << std::endl;
}
const auto optional_vel = _link.WorldLinearVelocity(_ecm);
if (optional_vel.has_value()) {
_vehicle_velocity = optional_vel.value();
} else {
gzerr << "Unable to get linear velocity" << std::endl;
}
// Compute the air density at the local altitude / temperature
const float alt_rel = _vehicle_position.Z(); // Z-component from ENU
const float alt_amsl = (float)_alt_home + alt_rel;
const float temperature_local = TEMPERATURE_MSL - LAPSE_RATE * alt_amsl;
const float density_ratio = powf(TEMPERATURE_MSL / temperature_local, 4.256f);
const float air_density = AIR_DENSITY_MSL / density_ratio;
// Calculate differential pressure + noise in hPa
const float diff_pressure_noise = standard_normal_distribution_(random_generator_) * diff_pressure_stddev_;
// Body-relateive air velocity
gz::math::Vector3d air_relative_velocity = _vehicle_velocity - _wind_velocity;
gz::math::Vector3d body_velocity = _vehicle_attitude.RotateVectorReverse(air_relative_velocity);
// Calculate differential pressure in hPa
double diff_pressure = sign(body_velocity.X()) * 0.005 * (double)air_density * body_velocity.X() * body_velocity.X() +
(double)diff_pressure_noise;
gz::msgs::AirSpeed airspeed_msg;
airspeed_msg.set_diff_pressure(diff_pressure * 100.0);
_pub.Publish(airspeed_msg);
}
void AirSpeed::windCallback(const gz::msgs::Wind &msg)
{
_wind_velocity = gz::math::Vector3d(msg.linear_velocity().x(), msg.linear_velocity().y(), msg.linear_velocity().z());
}