pose_estimation_node.cpp

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//=================================================================================================
// Copyright (c) 2011, 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
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//=================================================================================================
 
#include <hector_pose_estimation/pose_estimation_node.h>
#include <hector_pose_estimation/ros/parameters.h>
 
#include <hector_pose_estimation/system/generic_quaternion_system_model.h>
#include <hector_pose_estimation/system/imu_input.h>
#include <hector_pose_estimation/system/imu_model.h>
#include <hector_pose_estimation/measurements/poseupdate.h>
#include <hector_pose_estimation/measurements/baro.h>
#include <hector_pose_estimation/measurements/height.h>
#include <hector_pose_estimation/measurements/magnetic.h>
#include <hector_pose_estimation/measurements/gps.h>
 
#ifdef USE_HECTOR_TIMING
  #include <hector_diagnostics/timing.h>
#endif
 
namespace hector_pose_estimation {
 
PoseEstimationNode::PoseEstimationNode(const SystemPtr& system, const StatePtr& state)
  : pose_estimation_(new PoseEstimation(system, state))
  , private_nh_("~")
  , transform_listener_(0)
  , world_nav_transform_updated_(true)
  , world_nav_transform_valid_(false)
  , sensor_pose_roll_(0), sensor_pose_pitch_(0), sensor_pose_yaw_(0)
{
  if (!system) pose_estimation_->addSystem(new GenericQuaternionSystemModel);
 
  pose_estimation_->addInput(new ImuInput, "imu");
  pose_estimation_->addMeasurement(new PoseUpdate("poseupdate"));
#if defined(USE_HECTOR_UAV_MSGS)
  pose_estimation_->addMeasurement(new Baro("baro"));
#endif
  pose_estimation_->addMeasurement(new Height("height"));
  pose_estimation_->addMeasurement(new Magnetic("magnetic"));
  pose_estimation_->addMeasurement(new GPS("gps"));
}
 
PoseEstimationNode::~PoseEstimationNode()
{
  cleanup();
  delete pose_estimation_;
  delete transform_listener_;
}
 
bool PoseEstimationNode::init() {
  // get parameters
  pose_estimation_->parameters().initialize(ParameterRegistryROS(getPrivateNodeHandle()));
  getPrivateNodeHandle().getParam("publish_covariances", publish_covariances_ = false);
  if (getPrivateNodeHandle().getParam("publish_world_map_transform", publish_world_other_transform_ = false)) {
    ROS_WARN("Parameter 'publish_world_map_transform' is deprecated. Use 'publish_world_other_transform' and 'other_frame' instead.");
  }
  getPrivateNodeHandle().getParam("publish_world_other_transform", publish_world_other_transform_);
  if (getPrivateNodeHandle().getParam("map_frame", other_frame_ = std::string())) {
    ROS_WARN("Parameter 'map_frame' is deprecated. Use 'other_frame' instead.");
  }
  getPrivateNodeHandle().getParam("other_frame", other_frame_);
  getPrivateNodeHandle().getParam("publish_world_nav_transform", publish_world_nav_transform_ = false);
 
  // search tf_prefix parameter
  tf_prefix_ = tf::getPrefixParam(getPrivateNodeHandle());
  if (!tf_prefix_.empty()) ROS_INFO("Using tf_prefix '%s'", tf_prefix_.c_str());
 
  // initialize pose estimation
  if (!pose_estimation_->init()) {
    ROS_ERROR("Intitialization of pose estimation failed!");
    return false;
  }
 
  imu_subscriber_        = getNodeHandle().subscribe("raw_imu", 10, &PoseEstimationNode::imuCallback, this);
  ahrs_subscriber_       = getNodeHandle().subscribe("ahrs", 10, &PoseEstimationNode::ahrsCallback, this);
  rollpitch_subscriber_  = getNodeHandle().subscribe("rollpitch", 10, &PoseEstimationNode::rollpitchCallback, this);
#if defined(USE_HECTOR_UAV_MSGS)
  baro_subscriber_       = getNodeHandle().subscribe("altimeter", 10, &PoseEstimationNode::baroCallback, this);
#else
  height_subscriber_     = getNodeHandle().subscribe("pressure_height", 10, &PoseEstimationNode::heightCallback, this);
#endif
  magnetic_subscriber_   = getNodeHandle().subscribe("magnetic", 10, &PoseEstimationNode::magneticCallback, this);
 
  gps_subscriber_.subscribe(getNodeHandle(), "fix", 10);
  gps_velocity_subscriber_.subscribe(getNodeHandle(), "fix_velocity", 10);
  gps_synchronizer_ = new message_filters::TimeSynchronizer<sensor_msgs::NavSatFix,geometry_msgs::Vector3Stamped>(gps_subscriber_, gps_velocity_subscriber_, 10);
  gps_synchronizer_->registerCallback(&PoseEstimationNode::gpsCallback, this);
 
  state_publisher_       = getNodeHandle().advertise<nav_msgs::Odometry>("state", 10, false);
  pose_publisher_        = getNodeHandle().advertise<geometry_msgs::PoseStamped>("pose", 10, false);
  velocity_publisher_    = getNodeHandle().advertise<geometry_msgs::Vector3Stamped>("velocity", 10, false);
  imu_publisher_         = getNodeHandle().advertise<sensor_msgs::Imu>("imu", 10, false);
  geopose_publisher_     = getNodeHandle().advertise<geographic_msgs::GeoPose>("geopose", 10, false);
  global_fix_publisher_  = getNodeHandle().advertise<sensor_msgs::NavSatFix>("global", 10, false);
  euler_publisher_       = getNodeHandle().advertise<geometry_msgs::Vector3Stamped>("euler", 10, false);
 
  angular_velocity_bias_publisher_    = getNodeHandle().advertise<geometry_msgs::Vector3Stamped>("angular_velocity_bias", 10, false);
  linear_acceleration_bias_publisher_ = getNodeHandle().advertise<geometry_msgs::Vector3Stamped>("linear_acceleration_bias", 10, false);
  gps_pose_publisher_                 = getNodeHandle().advertise<geometry_msgs::PoseStamped>("fix/pose", 10, false);
  sensor_pose_publisher_              = getNodeHandle().advertise<geometry_msgs::PoseStamped>("sensor_pose", 10, false);
 
  poseupdate_subscriber_  = getNodeHandle().subscribe("poseupdate", 10, &PoseEstimationNode::poseupdateCallback, this);
  twistupdate_subscriber_ = getNodeHandle().subscribe("twistupdate", 10, &PoseEstimationNode::twistupdateCallback, this);
  syscommand_subscriber_  = getNodeHandle().subscribe("syscommand", 10, &PoseEstimationNode::syscommandCallback, this);
 
#ifdef USE_HECTOR_TIMING
  timing_publisher_ = getPrivateNodeHandle().advertise<hector_diagnostics::TimingAggregator>("timing", 10, false);
#endif
 
  global_reference_publisher_  = getNodeHandle().advertise<geographic_msgs::GeoPose>("global/reference", 1, true);
  pose_estimation_->globalReference()->addUpdateCallback(boost::bind(&PoseEstimationNode::globalReferenceUpdated, this));
 
  // setup publish_world_nav_transform timer
  if (publish_world_nav_transform_) {
    double period = 0.1;
    getPrivateNodeHandle().getParam("publish_world_nav_transform_period", period);
    publish_world_nav_transform_period_ = ros::Duration(period);
    publish_world_nav_transform_timer_ = getNodeHandle().createTimer(publish_world_nav_transform_period_, &PoseEstimationNode::publishWorldNavTransform, this,
                                                                     /* oneshot = */ false, /* autostart = */ true);
  }
 
  // publish initial state
  publish();
 
  return true;
}
 
void PoseEstimationNode::reset() {
  pose_estimation_->reset();
 
  sensor_pose_ = geometry_msgs::PoseStamped();
  sensor_pose_roll_  = 0.0;
  sensor_pose_pitch_ = 0.0;
  sensor_pose_yaw_   = 0.0;
}
 
void PoseEstimationNode::cleanup() {
  if (gps_synchronizer_) {
    delete gps_synchronizer_;
    gps_synchronizer_ = 0;
  }
  publish_world_nav_transform_timer_.stop();
 
  pose_estimation_->cleanup();
}
 
void PoseEstimationNode::imuCallback(const sensor_msgs::ImuConstPtr& imu) {
  pose_estimation_->setInput(ImuInput(*imu));
  pose_estimation_->update(imu->header.stamp);
 
  // calculate roll and pitch purely from acceleration
  if (sensor_pose_publisher_) {
    tf::Vector3 linear_acceleration_body(imu->linear_acceleration.x, imu->linear_acceleration.y, imu->linear_acceleration.z);
    linear_acceleration_body.normalize();
    sensor_pose_roll_  =  atan2(linear_acceleration_body.y(), linear_acceleration_body.z());
    sensor_pose_pitch_ = -asin(linear_acceleration_body.x());
  }
 
  publish();
}
 
void PoseEstimationNode::ahrsCallback(const sensor_msgs::ImuConstPtr& ahrs) {
  pose_estimation_->state().setOrientation(Quaternion(ahrs->orientation.w, ahrs->orientation.x, ahrs->orientation.y, ahrs->orientation.z));
  pose_estimation_->setInput(ImuInput(*ahrs));
  pose_estimation_->update(ahrs->header.stamp);
  publish();
}
 
void PoseEstimationNode::rollpitchCallback(const sensor_msgs::ImuConstPtr& attitude) {
  pose_estimation_->state().setRollPitch(Quaternion(attitude->orientation.w, attitude->orientation.x, attitude->orientation.y, attitude->orientation.z));
  pose_estimation_->setInput(ImuInput(*attitude));
  pose_estimation_->update(attitude->header.stamp);
  publish();
}
 
#if defined(USE_HECTOR_UAV_MSGS)
void PoseEstimationNode::baroCallback(const hector_uav_msgs::AltimeterConstPtr& altimeter) {
  boost::shared_ptr<Baro> m = boost::static_pointer_cast<Baro>(pose_estimation_->getMeasurement("baro"));
  m->add(Baro::Update(altimeter->pressure, altimeter->qnh));
}
 
#else
void PoseEstimationNode::heightCallback(const geometry_msgs::PointStampedConstPtr& height) {
  boost::shared_ptr<Height> m = boost::static_pointer_cast<Height>(pose_estimation_->getMeasurement("height"));
 
  Height::MeasurementVector update;
  update(0) = height->point.z;
  m->add(Height::Update(update));
 
  if (sensor_pose_publisher_) {
    sensor_pose_.pose.position.z = height->point.z - m->getElevation();
  }
}
#endif
 
void PoseEstimationNode::magneticCallback(const geometry_msgs::Vector3StampedConstPtr& magnetic) {
  boost::shared_ptr<Magnetic> m = boost::static_pointer_cast<Magnetic>(pose_estimation_->getMeasurement("magnetic"));
 
  Magnetic::MeasurementVector update;
  update.x() = magnetic->vector.x;
  update.y() = magnetic->vector.y;
  update.z() = magnetic->vector.z;
  m->add(Magnetic::Update(update));
 
  if (sensor_pose_publisher_) {
    sensor_pose_yaw_ = -(m->getModel()->getTrueHeading(pose_estimation_->state(), update) - pose_estimation_->globalReference()->heading());
  }
}
 
void PoseEstimationNode::gpsCallback(const sensor_msgs::NavSatFixConstPtr& gps, const geometry_msgs::Vector3StampedConstPtr& gps_velocity) {
  boost::shared_ptr<GPS> m = boost::static_pointer_cast<GPS>(pose_estimation_->getMeasurement("gps"));
 
  if (gps->status.status == sensor_msgs::NavSatStatus::STATUS_NO_FIX) {
    if (m->getStatusFlags() > 0) m->reset(pose_estimation_->state());
    return;
  }
 
  GPS::Update update;
  update.latitude = gps->latitude * M_PI/180.0;
  update.longitude = gps->longitude * M_PI/180.0;
  update.velocity_north =  gps_velocity->vector.x;
  update.velocity_east  = -gps_velocity->vector.y;
  m->add(update);
 
  if (gps_pose_publisher_ || sensor_pose_publisher_) {
    geometry_msgs::PoseStamped gps_pose;
    pose_estimation_->getHeader(gps_pose.header);
    gps_pose.header.stamp = gps->header.stamp;
    GPSModel::MeasurementVector y = m->getVector(update, pose_estimation_->state());
 
    if (gps_pose_publisher_) {
      gps_pose.pose.position.x = y(0);
      gps_pose.pose.position.y = y(1);
      gps_pose.pose.position.z = gps->altitude - pose_estimation_->globalReference()->position().altitude;
      double track = atan2(gps_velocity->vector.y, gps_velocity->vector.x);
      gps_pose.pose.orientation.w = cos(track/2);
      gps_pose.pose.orientation.z = sin(track/2);
      gps_pose_publisher_.publish(gps_pose);
    }
 
    sensor_pose_.pose.position.x = y(0);
    sensor_pose_.pose.position.y = y(1);
  }
}
 
void PoseEstimationNode::poseupdateCallback(const geometry_msgs::PoseWithCovarianceStampedConstPtr& pose) {
  pose_estimation_->getMeasurement("poseupdate")->add(PoseUpdate::Update(pose));
 
  if (sensor_pose_publisher_) {
    if (pose->pose.covariance[0] > 0)  sensor_pose_.pose.position.x = pose->pose.pose.position.x;
    if (pose->pose.covariance[7] > 0)  sensor_pose_.pose.position.y = pose->pose.pose.position.y;
    if (pose->pose.covariance[14] > 0) sensor_pose_.pose.position.z = pose->pose.pose.position.z;
    tf::Quaternion q;
    double yaw, pitch, roll;
    tf::quaternionMsgToTF(pose->pose.pose.orientation, q);
    tf::Matrix3x3(q).getEulerYPR(yaw, pitch, roll);
    if (pose->pose.covariance[21] > 0) sensor_pose_roll_  = roll;
    if (pose->pose.covariance[28] > 0) sensor_pose_pitch_ = pitch;
    if (pose->pose.covariance[35] > 0) sensor_pose_yaw_   = yaw;
  }
}
 
void PoseEstimationNode::twistupdateCallback(const geometry_msgs::TwistWithCovarianceStampedConstPtr& twist) {
  pose_estimation_->getMeasurement("poseupdate")->add(PoseUpdate::Update(twist));
}
 
void PoseEstimationNode::syscommandCallback(const std_msgs::StringConstPtr& syscommand) {
  if (syscommand->data == "reset") {
    ROS_INFO("Resetting pose_estimation");
    pose_estimation_->reset();
    publish();
  }
}
 
void PoseEstimationNode::globalReferenceUpdated() {
  geographic_msgs::GeoPose geopose;
  pose_estimation_->globalReference()->getGeoPose(geopose);
  global_reference_publisher_.publish(geopose);
 
  // update world nav transform
  world_nav_transform_updated_ = true;
}
 
void PoseEstimationNode::publishWorldNavTransform(const ros::TimerEvent &) {
  if (world_nav_transform_updated_) {
    world_nav_transform_valid_ = pose_estimation_->getWorldToNavTransform(world_nav_transform_);
    world_nav_transform_updated_ = false;
  }
 
  if (world_nav_transform_valid_) {
    world_nav_transform_.header.stamp = ros::Time::now() + publish_world_nav_transform_period_;
    getTransformBroadcaster()->sendTransform(world_nav_transform_);
  }
}
 
void PoseEstimationNode::publish() {
  if (state_publisher_ && state_publisher_.getNumSubscribers() > 0) {
    nav_msgs::Odometry state;
    pose_estimation_->getState(state, publish_covariances_);
    state_publisher_.publish(state);
  }
 
  if (pose_publisher_ && pose_publisher_.getNumSubscribers() > 0) {
    geometry_msgs::PoseStamped pose_msg;
    pose_estimation_->getPose(pose_msg);
    pose_publisher_.publish(pose_msg);
  }
 
  if (imu_publisher_ && imu_publisher_.getNumSubscribers() > 0) {
    sensor_msgs::Imu imu_msg;
    pose_estimation_->getHeader(imu_msg.header);
    pose_estimation_->getOrientation(imu_msg.orientation);
    pose_estimation_->getImuWithBiases(imu_msg.linear_acceleration, imu_msg.angular_velocity);
    imu_publisher_.publish(imu_msg);
  }
 
  if (velocity_publisher_ && velocity_publisher_.getNumSubscribers() > 0) {
    geometry_msgs::Vector3Stamped velocity_msg;
    pose_estimation_->getVelocity(velocity_msg);
    velocity_publisher_.publish(velocity_msg);
  }
 
  if (geopose_publisher_ && geopose_publisher_.getNumSubscribers() > 0) {
    geographic_msgs::GeoPose geopose_msg;
    pose_estimation_->getGlobal(geopose_msg);
    geopose_publisher_.publish(geopose_msg);
  }
 
  if (global_fix_publisher_ && global_fix_publisher_.getNumSubscribers() > 0) {
    sensor_msgs::NavSatFix global_msg;
    pose_estimation_->getGlobal(global_msg);
    global_fix_publisher_.publish(global_msg);
  }
 
  if (euler_publisher_ && euler_publisher_.getNumSubscribers() > 0) {
    geometry_msgs::Vector3Stamped euler_msg;
    pose_estimation_->getHeader(euler_msg.header);
    pose_estimation_->getOrientation(euler_msg.vector.z, euler_msg.vector.y, euler_msg.vector.x);
    euler_publisher_.publish(euler_msg);
  }
 
  if ((angular_velocity_bias_publisher_ && angular_velocity_bias_publisher_.getNumSubscribers() > 0) ||
      (linear_acceleration_bias_publisher_ && linear_acceleration_bias_publisher_.getNumSubscribers() > 0)) {
    geometry_msgs::Vector3Stamped angular_velocity_msg, linear_acceleration_msg;
    pose_estimation_->getBias(angular_velocity_msg, linear_acceleration_msg);
    if (angular_velocity_bias_publisher_) angular_velocity_bias_publisher_.publish(angular_velocity_msg);
    if (linear_acceleration_bias_publisher_) linear_acceleration_bias_publisher_.publish(linear_acceleration_msg);
  }
 
  if (sensor_pose_publisher_ && sensor_pose_publisher_.getNumSubscribers() > 0) {
    pose_estimation_->getHeader(sensor_pose_.header);
    tf::Quaternion orientation;
    orientation.setRPY(sensor_pose_roll_, sensor_pose_pitch_, sensor_pose_yaw_);
    tf::quaternionTFToMsg(orientation, sensor_pose_.pose.orientation);
    sensor_pose_publisher_.publish(sensor_pose_);
  }
 
  if (getTransformBroadcaster())
  {
    transforms_.clear();
 
    pose_estimation_->getTransforms(transforms_);
 
    if (publish_world_other_transform_) {
      tf::StampedTransform world_to_other_transform;
      std::string nav_frame = pose_estimation_->parameters().getAs<std::string>("nav_frame");
      try {
        getTransformListener()->lookupTransform(nav_frame, other_frame_, ros::Time(), world_to_other_transform);
        pose_estimation_->updateWorldToOtherTransform(world_to_other_transform);
        transforms_.push_back(world_to_other_transform);
 
      } catch (tf::TransformException& e) {
        ROS_WARN("Could not find a transformation from %s to %s to publish the world transformation", nav_frame.c_str(), other_frame_.c_str());
      }
    }
 
    // resolve tf frames
    for(std::vector<tf::StampedTransform>::iterator t = transforms_.begin(); t != transforms_.end(); t++) {
      t->frame_id_       = tf::resolve(tf_prefix_, t->frame_id_);
      t->child_frame_id_ = tf::resolve(tf_prefix_, t->child_frame_id_);
    }
 
    getTransformBroadcaster()->sendTransform(transforms_);
  }
 
#ifdef USE_HECTOR_TIMING
  timing_publisher_.publish(*hector_diagnostics::TimingAggregator::Instance());
#endif
}
 
tf::TransformBroadcaster *PoseEstimationNode::getTransformBroadcaster() {
  return &transform_broadcaster_;
}
 
tf::TransformListener *PoseEstimationNode::getTransformListener() {
  if (!transform_listener_) transform_listener_ = new tf::TransformListener();
  return transform_listener_;
}
 
} // namespace hector_pose_estimation