rawdata.cc

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/*
 *  Copyright (C) 2007 Austin Robot Technology, Patrick Beeson
 *  Copyright (C) 2009, 2010, 2012 Austin Robot Technology, Jack O'Quin
 *
 *  License: Modified BSD Software License Agreement
 *
 *  $Id$
 */

#include <fstream>
#include <math.h>

#include <ros/ros.h>
#include <ros/package.h>
#include <angles/angles.h>

#include <velodyne_pointcloud/rawdata.h>

namespace velodyne_rawdata
{
inline float SQR(float val) { return val*val; }

  //
  // RawData base class implementation
  //

  RawData::RawData() {}
  
  void RawData::setParameters(double min_range,
                              double max_range,
                              double view_direction,
                              double view_width)
  {
    config_.min_range = min_range;
    config_.max_range = max_range;

    //converting angle parameters into the velodyne reference (rad)
    config_.tmp_min_angle = view_direction + view_width/2;
    config_.tmp_max_angle = view_direction - view_width/2;
    
    //computing positive modulo to keep theses angles into [0;2*M_PI]
    config_.tmp_min_angle = fmod(fmod(config_.tmp_min_angle,2*M_PI) + 2*M_PI,2*M_PI);
    config_.tmp_max_angle = fmod(fmod(config_.tmp_max_angle,2*M_PI) + 2*M_PI,2*M_PI);
    
    //converting into the hardware velodyne ref (negative yaml and degrees)
    //adding 0.5 perfomrs a centered double to int conversion 
    config_.min_angle = 100 * (2*M_PI - config_.tmp_min_angle) * 180 / M_PI + 0.5;
    config_.max_angle = 100 * (2*M_PI - config_.tmp_max_angle) * 180 / M_PI + 0.5;
    if (config_.min_angle == config_.max_angle)
    {
      //avoid returning empty cloud if min_angle = max_angle
      config_.min_angle = 0;
      config_.max_angle = 36000;
    }
  }

  int RawData::scansPerPacket() const
  {
    if( calibration_.num_lasers == 16)
    {
      return BLOCKS_PER_PACKET * VLP16_FIRINGS_PER_BLOCK *
          VLP16_SCANS_PER_FIRING;
    }
    else{
      return BLOCKS_PER_PACKET * SCANS_PER_BLOCK;
    }
  }

  boost::optional<velodyne_pointcloud::Calibration> RawData::setup(ros::NodeHandle private_nh)
  {
    // get path to angles.config file for this device
    if (!private_nh.getParam("calibration", config_.calibrationFile))
      {
        ROS_ERROR_STREAM("No calibration angles specified! Using test values!");

        // have to use something: grab unit test version as a default
        std::string pkgPath = ros::package::getPath("velodyne_pointcloud");
        config_.calibrationFile = pkgPath + "/params/64e_utexas.yaml";
      }

    ROS_INFO_STREAM("correction angles: " << config_.calibrationFile);

    calibration_.read(config_.calibrationFile);
    if (!calibration_.initialized) {
      ROS_ERROR_STREAM("Unable to open calibration file: " <<
          config_.calibrationFile);
      return boost::none;
    }

    ROS_INFO_STREAM("Number of lasers: " << calibration_.num_lasers << ".");

    // Set up cached values for sin and cos of all the possible headings
    for (uint16_t rot_index = 0; rot_index < ROTATION_MAX_UNITS; ++rot_index) {
      float rotation = angles::from_degrees(ROTATION_RESOLUTION * rot_index);
      cos_rot_table_[rot_index] = cosf(rotation);
      sin_rot_table_[rot_index] = sinf(rotation);
    }
   return calibration_;
  }


  int RawData::setupOffline(std::string calibration_file, double max_range_, double min_range_)
  {

      config_.max_range = max_range_;
      config_.min_range = min_range_;
      ROS_INFO_STREAM("data ranges to publish: ["
              << config_.min_range << ", "
              << config_.max_range << "]");

      config_.calibrationFile = calibration_file;

      ROS_INFO_STREAM("correction angles: " << config_.calibrationFile);

      calibration_.read(config_.calibrationFile);
      if (!calibration_.initialized) {
          ROS_ERROR_STREAM("Unable to open calibration file: " <<
                  config_.calibrationFile);
          return -1;
      }

      // Set up cached values for sin and cos of all the possible headings
      for (uint16_t rot_index = 0; rot_index < ROTATION_MAX_UNITS; ++rot_index) {
          float rotation = angles::from_degrees(ROTATION_RESOLUTION * rot_index);
          cos_rot_table_[rot_index] = cosf(rotation);
          sin_rot_table_[rot_index] = sinf(rotation);
      }
      return 0;
  }


  void RawData::unpack(const velodyne_msgs::VelodynePacket &pkt, DataContainerBase& data)
  {
    using velodyne_pointcloud::LaserCorrection;
    ROS_DEBUG_STREAM("Received packet, time: " << pkt.stamp);

    if (calibration_.num_lasers == 16)
    {
      unpack_vlp16(pkt, data);
      return;
    }
    
    const raw_packet_t *raw = (const raw_packet_t *) &pkt.data[0];

    for (int i = 0; i < BLOCKS_PER_PACKET; i++) {

      // upper bank lasers are numbered [0..31]
      // NOTE: this is a change from the old velodyne_common implementation

      int bank_origin = 0;
      if (raw->blocks[i].header == LOWER_BANK) {
        // lower bank lasers are [32..63]
        bank_origin = 32;
      }

      for (int j = 0, k = 0; j < SCANS_PER_BLOCK; j++, k += RAW_SCAN_SIZE) {
        
        float x, y, z;
        float intensity;
        const uint8_t laser_number  = j + bank_origin;

        const LaserCorrection &corrections = calibration_.laser_corrections[laser_number];

        const raw_block_t &block = raw->blocks[i];
        union two_bytes tmp;
        tmp.bytes[0] = block.data[k];
        tmp.bytes[1] = block.data[k+1];
        if (tmp.bytes[0]==0 &&tmp.bytes[1]==0 ) //no laser beam return
        {
          continue;
        }

        /*condition added to avoid calculating points which are not
          in the interesting defined area (min_angle < area < max_angle)*/
        if ((block.rotation >= config_.min_angle
             && block.rotation <= config_.max_angle
             && config_.min_angle < config_.max_angle)
             ||(config_.min_angle > config_.max_angle 
             && (raw->blocks[i].rotation <= config_.max_angle 
             || raw->blocks[i].rotation >= config_.min_angle))){
          float distance = tmp.uint * calibration_.distance_resolution_m;
          distance += corrections.dist_correction;
  
          float cos_vert_angle = corrections.cos_vert_correction;
          float sin_vert_angle = corrections.sin_vert_correction;
          float cos_rot_correction = corrections.cos_rot_correction;
          float sin_rot_correction = corrections.sin_rot_correction;
  
          // cos(a-b) = cos(a)*cos(b) + sin(a)*sin(b)
          // sin(a-b) = sin(a)*cos(b) - cos(a)*sin(b)
          float cos_rot_angle = 
            cos_rot_table_[block.rotation] * cos_rot_correction +
            sin_rot_table_[block.rotation] * sin_rot_correction;
          float sin_rot_angle = 
            sin_rot_table_[block.rotation] * cos_rot_correction -
            cos_rot_table_[block.rotation] * sin_rot_correction;
  
          float horiz_offset = corrections.horiz_offset_correction;
          float vert_offset = corrections.vert_offset_correction;
  
          // Compute the distance in the xy plane (w/o accounting for rotation)
          float xy_distance = distance * cos_vert_angle - vert_offset * sin_vert_angle;
  
          // Calculate temporal X, use absolute value.
          float xx = xy_distance * sin_rot_angle - horiz_offset * cos_rot_angle;
          // Calculate temporal Y, use absolute value
          float yy = xy_distance * cos_rot_angle + horiz_offset * sin_rot_angle;
          if (xx < 0) xx=-xx;
          if (yy < 0) yy=-yy;
    
          // Get 2points calibration values,Linear interpolation to get distance
          // correction for X and Y, that means distance correction use
          // different value at different distance
          float distance_corr_x = 0;
          float distance_corr_y = 0;
          if (corrections.two_pt_correction_available) {
            distance_corr_x = 
              (corrections.dist_correction - corrections.dist_correction_x)
                * (xx - 2.4) / (25.04 - 2.4) 
              + corrections.dist_correction_x;
            distance_corr_x -= corrections.dist_correction;
            distance_corr_y = 
              (corrections.dist_correction - corrections.dist_correction_y)
                * (yy - 1.93) / (25.04 - 1.93)
              + corrections.dist_correction_y;
            distance_corr_y -= corrections.dist_correction;
          }
  
          float distance_x = distance + distance_corr_x;
          xy_distance = distance_x * cos_vert_angle - vert_offset * sin_vert_angle ;
          x = xy_distance * sin_rot_angle - horiz_offset * cos_rot_angle;
  
          float distance_y = distance + distance_corr_y;
          xy_distance = distance_y * cos_vert_angle - vert_offset * sin_vert_angle ;
          y = xy_distance * cos_rot_angle + horiz_offset * sin_rot_angle;
  
          // Using distance_y is not symmetric, but the velodyne manual
          // does this.
          z = distance_y * sin_vert_angle + vert_offset*cos_vert_angle;
  
          float x_coord = y;
          float y_coord = -x;
          float z_coord = z;
  
          float min_intensity = corrections.min_intensity;
          float max_intensity = corrections.max_intensity;
  
          intensity = raw->blocks[i].data[k+2];
  
          float focal_offset = 256 
                             * (1 - corrections.focal_distance / 13100) 
                             * (1 - corrections.focal_distance / 13100);
          float focal_slope = corrections.focal_slope;
          intensity += focal_slope * (std::abs(focal_offset - 256 * 
            SQR(1 - static_cast<float>(tmp.uint)/65535)));
          intensity = (intensity < min_intensity) ? min_intensity : intensity;
          intensity = (intensity > max_intensity) ? max_intensity : intensity;

          data.addPoint(x_coord, y_coord, z_coord, corrections.laser_ring, raw->blocks[i].rotation, distance, intensity);
        }
      }
      data.newLine();
    }
  }
  
  void RawData::unpack_vlp16(const velodyne_msgs::VelodynePacket &pkt, DataContainerBase& data)
  {
    float azimuth;
    float azimuth_diff;
    int raw_azimuth_diff;
    float last_azimuth_diff=0;
    float azimuth_corrected_f;
    int azimuth_corrected;
    float x, y, z;
    float intensity;

    const raw_packet_t *raw = (const raw_packet_t *) &pkt.data[0];

    for (int block = 0; block < BLOCKS_PER_PACKET; block++) {

      // ignore packets with mangled or otherwise different contents
      if (UPPER_BANK != raw->blocks[block].header) {
        // Do not flood the log with messages, only issue at most one
        // of these warnings per minute.
        ROS_WARN_STREAM_THROTTLE(60, "skipping invalid VLP-16 packet: block "
                                 << block << " header value is "
                                 << raw->blocks[block].header);
        return;                         // bad packet: skip the rest
      }

      // Calculate difference between current and next block's azimuth angle.
      azimuth = (float)(raw->blocks[block].rotation);
      if (block < (BLOCKS_PER_PACKET-1)){
        raw_azimuth_diff = raw->blocks[block+1].rotation - raw->blocks[block].rotation;
        azimuth_diff = (float)((36000 + raw_azimuth_diff)%36000);
        // some packets contain an angle overflow where azimuth_diff < 0 
        if(raw_azimuth_diff < 0)//raw->blocks[block+1].rotation - raw->blocks[block].rotation < 0)
          {
            ROS_WARN_STREAM_THROTTLE(60, "Packet containing angle overflow, first angle: " << raw->blocks[block].rotation << " second angle: " << raw->blocks[block+1].rotation);
            // if last_azimuth_diff was not zero, we can assume that the velodyne's speed did not change very much and use the same difference
            if(last_azimuth_diff > 0){
              azimuth_diff = last_azimuth_diff;
            }
            // otherwise we are not able to use this data
            // TODO: we might just not use the second 16 firings
            else{
              continue;
            }
          }
        last_azimuth_diff = azimuth_diff;
      }else{
        azimuth_diff = last_azimuth_diff;
      }

      for (int firing=0, k=0; firing < VLP16_FIRINGS_PER_BLOCK; firing++){
        for (int dsr=0; dsr < VLP16_SCANS_PER_FIRING; dsr++, k+=RAW_SCAN_SIZE){
          velodyne_pointcloud::LaserCorrection &corrections = calibration_.laser_corrections[dsr];

          union two_bytes tmp;
          tmp.bytes[0] = raw->blocks[block].data[k];
          tmp.bytes[1] = raw->blocks[block].data[k+1];
          
          azimuth_corrected_f = azimuth + (azimuth_diff * ((dsr*VLP16_DSR_TOFFSET) + (firing*VLP16_FIRING_TOFFSET)) / VLP16_BLOCK_TDURATION);
          azimuth_corrected = ((int)round(azimuth_corrected_f)) % 36000;
                 
          /*condition added to avoid calculating points which are not
            in the interesting defined area (min_angle < area < max_angle)*/
          if ((azimuth_corrected >= config_.min_angle 
               && azimuth_corrected <= config_.max_angle 
               && config_.min_angle < config_.max_angle)
               ||(config_.min_angle > config_.max_angle 
               && (azimuth_corrected <= config_.max_angle 
               || azimuth_corrected >= config_.min_angle))){

            // convert polar coordinates to Euclidean XYZ
            float distance = tmp.uint * calibration_.distance_resolution_m;
            distance += corrections.dist_correction;
            
            float cos_vert_angle = corrections.cos_vert_correction;
            float sin_vert_angle = corrections.sin_vert_correction;
            float cos_rot_correction = corrections.cos_rot_correction;
            float sin_rot_correction = corrections.sin_rot_correction;
    
            // cos(a-b) = cos(a)*cos(b) + sin(a)*sin(b)
            // sin(a-b) = sin(a)*cos(b) - cos(a)*sin(b)
            float cos_rot_angle = 
              cos_rot_table_[azimuth_corrected] * cos_rot_correction + 
              sin_rot_table_[azimuth_corrected] * sin_rot_correction;
            float sin_rot_angle = 
              sin_rot_table_[azimuth_corrected] * cos_rot_correction - 
              cos_rot_table_[azimuth_corrected] * sin_rot_correction;
    
            float horiz_offset = corrections.horiz_offset_correction;
            float vert_offset = corrections.vert_offset_correction;
    
            // Compute the distance in the xy plane (w/o accounting for rotation)
            float xy_distance = distance * cos_vert_angle - vert_offset * sin_vert_angle;
    
            // Calculate temporal X, use absolute value.
            float xx = xy_distance * sin_rot_angle - horiz_offset * cos_rot_angle;
            // Calculate temporal Y, use absolute value
            float yy = xy_distance * cos_rot_angle + horiz_offset * sin_rot_angle;
            if (xx < 0) xx=-xx;
            if (yy < 0) yy=-yy;
      
            // Get 2points calibration values,Linear interpolation to get distance
            // correction for X and Y, that means distance correction use
            // different value at different distance
            float distance_corr_x = 0;
            float distance_corr_y = 0;
            if (corrections.two_pt_correction_available) {
              distance_corr_x = 
                (corrections.dist_correction - corrections.dist_correction_x)
                  * (xx - 2.4) / (25.04 - 2.4) 
                + corrections.dist_correction_x;
              distance_corr_x -= corrections.dist_correction;
              distance_corr_y = 
                (corrections.dist_correction - corrections.dist_correction_y)
                  * (yy - 1.93) / (25.04 - 1.93)
                + corrections.dist_correction_y;
              distance_corr_y -= corrections.dist_correction;
            }
    
            float distance_x = distance + distance_corr_x;
            xy_distance = distance_x * cos_vert_angle - vert_offset * sin_vert_angle ;
            x = xy_distance * sin_rot_angle - horiz_offset * cos_rot_angle;
    
            float distance_y = distance + distance_corr_y;
            xy_distance = distance_y * cos_vert_angle - vert_offset * sin_vert_angle ;
            y = xy_distance * cos_rot_angle + horiz_offset * sin_rot_angle;
    
            // Using distance_y is not symmetric, but the velodyne manual
            // does this.
            z = distance_y * sin_vert_angle + vert_offset*cos_vert_angle;
  
    
            float x_coord = y;
            float y_coord = -x;
            float z_coord = z;
    
            float min_intensity = corrections.min_intensity;
            float max_intensity = corrections.max_intensity;
    
            intensity = raw->blocks[block].data[k+2];
    
            float focal_offset = 256 * SQR(1 - corrections.focal_distance / 13100);
            float focal_slope = corrections.focal_slope;
            intensity += focal_slope * (std::abs(focal_offset - 256 * 
              SQR(1 - tmp.uint/65535)));
            intensity = (intensity < min_intensity) ? min_intensity : intensity;
            intensity = (intensity > max_intensity) ? max_intensity : intensity;
    
            data.addPoint(x_coord, y_coord, z_coord, corrections.laser_ring, azimuth_corrected, distance, intensity);
          }
        }
        data.newLine();
      }
    }
  }
} // namespace velodyne_rawdata