ROS学习之depthimage_to_laserscan提取

ROS学习之depthimage_to_laserscan提取

使用ROS的过程中，我们在用Intel的realsense进行提取深度图像获得障碍物地图的过程中，需要用到depthimage_to_laserscan进行对三维图像-伪激光图的转换。我们获得的laserscan需要传输给其他节点，这里我们尝试对laserscan中的信息进行提取。

首先在depthimage_to_laserscan中的代码进行阅读，可以找到

DepthImageToLaserScanROS::DepthImageToLaserScanROS(ros::NodeHandle& n, ros::NodeHandle& pnh):pnh_(pnh), it_(n), srv_(pnh) {
  boost::mutex::scoped_lock lock(connect_mutex_);
  
  // Dynamic Reconfigure
  dynamic_reconfigure::Server::CallbackType f;
  f = boost::bind(&DepthImageToLaserScanROS::reconfigureCb, this, _1, _2);
  srv_.setCallback(f);
  
  // Lazy subscription to depth image topic
  pub_ = n.advertise("scan", 10, boost::bind(&DepthImageToLaserScanROS::connectCb, this, _1), boost::bind(&DepthImageToLaserScanROS::disconnectCb, this, _1));
}

DepthImageToLaserScanROS::~DepthImageToLaserScanROS(){
  sub_.shutdown();
}

其中可以找到以"scan"的topic发表的信息

  // Lazy subscription to depth image topic
  pub_ = n.advertise("scan", 10, boost::bind(&DepthImageToLaserScanROS::connectCb, this, _1), boost::bind(&DepthImageToLaserScanROS::disconnectCb, this, _1));

可以找到信息格式为sensor_msgs::LaserScan
查阅API可以得到原始数据格式

# Single scan from a planar laser range-finder
#
# If you have another ranging device with different behavior (e.g. a sonar
# array), please find or create a different message, since applications
# will make fairly laser-specific assumptions about this data

Header header            # timestamp in the header is the acquisition time of 
                         # the first ray in the scan.
                         #
                         # in frame frame_id, angles are measured around 
                         # the positive Z axis (counterclockwise, if Z is up)
                         # with zero angle being forward along the x axis
                         
float32 angle_min        # start angle of the scan [rad]
float32 angle_max        # end angle of the scan [rad]
float32 angle_increment  # angular distance between measurements [rad]

float32 time_increment   # time between measurements [seconds] - if your scanner
                         # is moving, this will be used in interpolating position
                         # of 3d points
float32 scan_time        # time between scans [seconds]

float32 range_min        # minimum range value [m]
float32 range_max        # maximum range value [m]

float32[] ranges         # range data [m] (Note: values < range_min or > range_max should be discarded)
float32[] intensities    # intensity data [device-specific units].  If your
                         # device does not provide intensities, please leave
                         # the array empty.

其中

std_msgs/Header header
float32 angle_min
float32 angle_max
float32 angle_increment
float32 time_increment
float32 scan_time
float32 range_min
float32 range_max
float32[] ranges
float32[] intensities