gazebo_ros_magnetic.cpp

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//=================================================================================================
// Copyright (c) 2012, Johannes Meyer, TU Darmstadt
// All rights reserved.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * 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.
//     * Neither the name of the Flight Systems and Automatic Control group,
//       TU Darmstadt, 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 HOLDER 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 <hector_gazebo_plugins/gazebo_ros_magnetic.h>
#include <gazebo/common/Events.hh>
#include <gazebo/physics/physics.hh>

static const double DEFAULT_MAGNITUDE           = 1.0;
static const double DEFAULT_REFERENCE_HEADING   = 0.0;
static const double DEFAULT_DECLINATION         = 0.0;
static const double DEFAULT_INCLINATION         = 60.0;

namespace gazebo {

GazeboRosMagnetic::GazeboRosMagnetic()
{
}

// Destructor
GazeboRosMagnetic::~GazeboRosMagnetic()
{
  updateTimer.Disconnect(updateConnection);
  node_handle_->shutdown();
  delete node_handle_;
}

// Load the controller
void GazeboRosMagnetic::Load(physics::ModelPtr _model, sdf::ElementPtr _sdf)
{
  world = _model->GetWorld();

  // load parameters
  if (!_sdf->HasElement("robotNamespace"))
    namespace_.clear();
  else
    namespace_ = _sdf->GetElement("robotNamespace")->GetValueString() + "/";

  if (!_sdf->HasElement("topicName"))
    topic_ = "magnetic";
  else
    topic_ = _sdf->GetElement("topicName")->GetValueString();

  if (!_sdf->HasElement("bodyName"))
  {
    link = _model->GetLink();
    link_name_ = link->GetName();
  }
  else {
    link_name_ = _sdf->GetElement("bodyName")->GetValueString();
    link = _model->GetLink(link_name_);
  }

  if (!link)
  {
    ROS_FATAL("GazeboRosMagnetic plugin error: bodyName: %s does not exist\n", link_name_.c_str());
    return;
  }

  if (!_sdf->HasElement("frameId"))
    frame_id_ = link_name_;
  else
    frame_id_ = _sdf->GetElement("frameId")->GetValueString();

  if (!_sdf->HasElement("magnitude"))
    magnitude_ = DEFAULT_MAGNITUDE;
  else
    magnitude_ = _sdf->GetElement("magnitude")->GetValueDouble();

  if (!_sdf->HasElement("referenceHeading"))
    reference_heading_ = DEFAULT_REFERENCE_HEADING * M_PI/180.0;
  else
    reference_heading_ = _sdf->GetElement("referenceHeading")->GetValueDouble() * M_PI/180.0;

  if (!_sdf->HasElement("declination"))
    declination_ = DEFAULT_DECLINATION * M_PI/180.0;
  else
    declination_ = _sdf->GetElement("declination")->GetValueDouble() * M_PI/180.0;

  if (!_sdf->HasElement("inclination"))
    inclination_ = DEFAULT_INCLINATION * M_PI/180.0;
  else
    inclination_ = _sdf->GetElement("inclination")->GetValueDouble() * M_PI/180.0;

  // Note: Gazebo uses NorthWestUp coordinate system, heading and declination are compass headings
  magnetic_field_.header.frame_id = frame_id_;
  magnetic_field_world_.x = magnitude_ *  cos(inclination_) * cos(reference_heading_ - declination_);
  magnetic_field_world_.y = magnitude_ *  sin(reference_heading_ - declination_);
  magnetic_field_world_.z = magnitude_ * -sin(inclination_) * cos(reference_heading_ - declination_);

  sensor_model_.Load(_sdf);

  // start ros node
  if (!ros::isInitialized())
  {
    int argc = 0;
    char** argv = NULL;
    ros::init(argc,argv,"gazebo",ros::init_options::NoSigintHandler|ros::init_options::AnonymousName);
  }

  node_handle_ = new ros::NodeHandle(namespace_);
  publisher_ = node_handle_->advertise<geometry_msgs::Vector3Stamped>(topic_, 1);

  Reset();

  // connect Update function
  updateTimer.Load(world, _sdf);
  updateConnection = updateTimer.Connect(boost::bind(&GazeboRosMagnetic::Update, this));
}

void GazeboRosMagnetic::Reset()
{
  updateTimer.Reset();
  sensor_model_.reset();
}

// Update the controller
void GazeboRosMagnetic::Update()
{
  common::Time sim_time = world->GetSimTime();
  double dt = updateTimer.getTimeSinceLastUpdate().Double();

  math::Pose pose = link->GetWorldPose();
  math::Vector3 field = sensor_model_(pose.rot.RotateVectorReverse(magnetic_field_world_), dt);

  magnetic_field_.header.stamp = ros::Time(sim_time.sec, sim_time.nsec);
  magnetic_field_.vector.x = field.x;
  magnetic_field_.vector.y = field.y;
  magnetic_field_.vector.z = field.z;

  publisher_.publish(magnetic_field_);
}

// Register this plugin with the simulator
GZ_REGISTER_MODEL_PLUGIN(GazeboRosMagnetic)

} // namespace gazebo