point_cloud_to_laserscan.cpp

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#include <pses_kinect_utilities/point_cloud_to_laserscan.h>
#include <sensor_msgs/LaserScan.h>
#include <pluginlib/class_list_macros.h>
#include <sensor_msgs/point_cloud2_iterator.h>
#include <tf2_sensor_msgs/tf2_sensor_msgs.h>

namespace pointcloud_to_laserscan
{

  PointCloudToLaserScanNodelet::PointCloudToLaserScanNodelet() {}

  void PointCloudToLaserScanNodelet::onInit()
  {
    boost::mutex::scoped_lock lock(connect_mutex_);
    private_nh_ = getPrivateNodeHandle();

    private_nh_.param<std::string>("target_frame", target_frame_, "");
    private_nh_.param<double>("transform_tolerance", tolerance_, 0.01);
    private_nh_.param<double>("min_height", min_height_, std::numeric_limits<double>::min());
    private_nh_.param<double>("max_height", max_height_, std::numeric_limits<double>::max());

    private_nh_.param<double>("angle_min", angle_min_, - M_PI);
    private_nh_.param<double>("angle_max", angle_max_, M_PI);
    private_nh_.param<double>("angle_increment", angle_increment_, M_PI / 180.0);
    private_nh_.param<double>("scan_time", scan_time_, 1.0 / 30.0);
    private_nh_.param<double>("range_min", range_min_, 0.0);
    private_nh_.param<double>("range_max", range_max_, std::numeric_limits<double>::max());
    private_nh_.param<double>("inf_epsilon", inf_epsilon_, 1.0);

    int concurrency_level;
    private_nh_.param<int>("concurrency_level", concurrency_level, 1);
    private_nh_.param<bool>("use_inf", use_inf_, true);

    //Check if explicitly single threaded, otherwise, let nodelet manager dictate thread pool size
    if (concurrency_level == 1)
    {
      nh_ = getNodeHandle();
    }
    else
    {
      nh_ = getMTNodeHandle();
    }

    // Only queue one pointcloud per running thread
    if (concurrency_level > 0)
    {
      input_queue_size_ = concurrency_level;
    }
    else
    {
      input_queue_size_ = boost::thread::hardware_concurrency();
    }

    // if pointcloud target frame specified, we need to filter by transform availability
    if (!target_frame_.empty())
    {
      tf2_.reset(new tf2_ros::Buffer());
      tf2_listener_.reset(new tf2_ros::TransformListener(*tf2_));
      message_filter_.reset(new MessageFilter(sub_, *tf2_, target_frame_, input_queue_size_, nh_));
      message_filter_->registerCallback(boost::bind(&PointCloudToLaserScanNodelet::cloudCb, this, _1));
      message_filter_->registerFailureCallback(boost::bind(&PointCloudToLaserScanNodelet::failureCb, this, _1, _2));
    }
    else // otherwise setup direct subscription
    {
      sub_.registerCallback(boost::bind(&PointCloudToLaserScanNodelet::cloudCb, this, _1));
    }

    pub_ = nh_.advertise<sensor_msgs::LaserScan>("scan", 10,
                                                 boost::bind(&PointCloudToLaserScanNodelet::connectCb, this),
                                                 boost::bind(&PointCloudToLaserScanNodelet::disconnectCb, this));
  }

  void PointCloudToLaserScanNodelet::connectCb()
  {
    boost::mutex::scoped_lock lock(connect_mutex_);
    if (pub_.getNumSubscribers() > 0 && sub_.getSubscriber().getNumPublishers() == 0)
    {
      NODELET_INFO("Got a subscriber to scan, starting subscriber to pointcloud");
      sub_.subscribe(nh_, "cloud_in", input_queue_size_);
    }
  }

  void PointCloudToLaserScanNodelet::disconnectCb()
  {
    boost::mutex::scoped_lock lock(connect_mutex_);
    if (pub_.getNumSubscribers() == 0)
    {
      NODELET_INFO("No subscibers to scan, shutting down subscriber to pointcloud");
      sub_.unsubscribe();
    }
  }

  void PointCloudToLaserScanNodelet::failureCb(const sensor_msgs::PointCloud2ConstPtr &cloud_msg,
                                               tf2_ros::filter_failure_reasons::FilterFailureReason reason)
  {
    NODELET_WARN_STREAM_THROTTLE(1.0, "Can't transform pointcloud from frame " << cloud_msg->header.frame_id << " to "
        << message_filter_->getTargetFramesString() << " at time " << cloud_msg->header.stamp << ", reason: " << reason);
  }

  void PointCloudToLaserScanNodelet::cloudCb(const sensor_msgs::PointCloud2ConstPtr &cloud_msg)
  {

    //build laserscan output
    sensor_msgs::LaserScan output;
    output.header = cloud_msg->header;
    if (!target_frame_.empty())
    {
      output.header.frame_id = target_frame_;
    }

    output.angle_min = angle_min_;
    output.angle_max = angle_max_;
    output.angle_increment = angle_increment_;
    output.time_increment = 0.0;
    output.scan_time = scan_time_;
    output.range_min = range_min_;
    output.range_max = range_max_;

    //determine amount of rays to create
    uint32_t ranges_size = std::ceil((output.angle_max - output.angle_min) / output.angle_increment);

    //determine if laserscan rays with no obstacle data will evaluate to infinity or max_range
    if (use_inf_)
    {
      output.ranges.assign(ranges_size, std::numeric_limits<double>::infinity());
    }
    else
    {
      output.ranges.assign(ranges_size, output.range_max + inf_epsilon_);
    }

    sensor_msgs::PointCloud2ConstPtr cloud_out;
    sensor_msgs::PointCloud2Ptr cloud;

    // Transform cloud if necessary
    if (!(output.header.frame_id == cloud_msg->header.frame_id))
    {
      try
      {
        cloud.reset(new sensor_msgs::PointCloud2);
        tf2_->transform(*cloud_msg, *cloud, target_frame_, ros::Duration(tolerance_));
        cloud_out = cloud;
      }
      catch (tf2::TransformException &ex)
      {
        NODELET_ERROR_STREAM("Transform failure: " << ex.what());
        return;
      }
    }
    else
    {
      cloud_out = cloud_msg;
    }

    // Iterate through pointcloud
    for (sensor_msgs::PointCloud2ConstIterator<float>
              iter_x(*cloud_out, "x"), iter_y(*cloud_out, "y"), iter_z(*cloud_out, "z");
              iter_x != iter_x.end();
              ++iter_x, ++iter_y, ++iter_z)
    {

      if (std::isnan(*iter_x) || std::isnan(*iter_y) || std::isnan(*iter_z))
      {
        NODELET_DEBUG("rejected for nan in point(%f, %f, %f)\n", *iter_x, *iter_y, *iter_z);
        continue;
      }

      if (*iter_z > max_height_ || *iter_z < min_height_)
      {
        NODELET_DEBUG("rejected for height %f not in range (%f, %f)\n", *iter_z, min_height_, max_height_);
        continue;
      }

      double range = hypot(*iter_x, *iter_y);
      if (range < range_min_)
      {
        NODELET_DEBUG("rejected for range %f below minimum value %f. Point: (%f, %f, %f)", range, range_min_, *iter_x, *iter_y,
                      *iter_z);
        continue;
      }

      double angle = atan2(*iter_y, *iter_x);
      if (angle < output.angle_min || angle > output.angle_max)
      {
        NODELET_DEBUG("rejected for angle %f not in range (%f, %f)\n", angle, output.angle_min, output.angle_max);
        continue;
      }

      //overwrite range at laserscan ray if new range is smaller
      int index = (angle - output.angle_min) / output.angle_increment;
      if (range < output.ranges[index])
      {
        output.ranges[index] = range;
      }

    }
    pub_.publish(output);
  }

}

PLUGINLIB_EXPORT_CLASS(pointcloud_to_laserscan::PointCloudToLaserScanNodelet, nodelet::Nodelet)