wall_extractor_pcl.cpp
Go to the documentation of this file.
00001 /*
00002  * Software License Agreement (BSD License)
00003  *
00004  *  Copyright (c) 2009, Willow Garage, Inc.
00005  *  All rights reserved.
00006  *
00007  *  Redistribution and use in source and binary forms, with or without
00008  *  modification, are permitted provided that the following conditions
00009  *  are met:
00010  *
00011  *   * Redistributions of source code must retain the above copyright
00012  *     notice, this list of conditions and the following disclaimer.
00013  *   * Redistributions in binary form must reproduce the above
00014  *     copyright notice, this list of conditions and the following
00015  *     disclaimer in the documentation and/or other materials provided
00016  *     with the distribution.
00017  *   * Neither the name of Willow Garage, Inc. nor the names of its
00018  *     contributors may be used to endorse or promote products derived
00019  *     from this software without specific prior written permission.
00020  *
00021  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00022  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00023  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00024  *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
00025  *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00026  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00027  *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00028  *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00029  *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030  *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00031  *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00032  *  POSSIBILITY OF SUCH DAMAGE.
00033  *
00034  * author: Wim Meeussen
00035  *
00036  */
00037 
00038 
00039 
00040 
00041 #include <ros/ros.h>
00042 #include <sensor_msgs/PointCloud2.h>
00043 #include <stereo_wall_detection/DetectWall.h>
00044 #include <pcl/ModelCoefficients.h>
00045 #include <pcl/io/pcd_io.h>
00046 #include <pcl/point_types.h>
00047 #include <pcl/sample_consensus/method_types.h>
00048 #include <pcl/sample_consensus/model_types.h>
00049 #include <pcl/segmentation/sac_segmentation.h>
00050 #include <pcl/ros/conversions.h>
00051 #include <pcl/io/io.h>
00052 #include <pcl/features/feature.h>
00053 #include <pcl/point_types.h>
00054 #include <boost/thread/mutex.hpp>
00055 #include <boost/thread/condition.hpp>
00056 #include <boost/bind.hpp>
00057 
00058 #include <visualization_msgs/Marker.h>
00059 
00060 class PlanarFit
00061 {
00062 public:
00063   PlanarFit () : nh_ ("~")
00064   {
00065     serv_ = nh_.advertiseService ("detect_wall", &PlanarFit::detect_wall, this);
00066 
00067     // subscribe to pointcloud messages from stereo camera
00068     //cloud_sub_ = nh_.subscribe("points2", 10, boost::bind(&PlanarFit::cloudCb, this, _1));  // what's wrong with this line???
00069     cloud_sub_ = nh_.subscribe("points2", 10, &PlanarFit::cloudCb, this);
00070 
00071     // advertise selected points from wall detection algorithm
00072     plane_points_ = nh_.advertise<sensor_msgs::PointCloud2>("wall_points", 10);
00073     plane_marker_ = nh_.advertise<visualization_msgs::Marker>("wall_marker", 10);
00074   }
00075   
00076   virtual ~PlanarFit () { }
00077   
00078 
00079 
00080   //void cloudCb(const sensor_msgs::PointCloud2ConstPtr& cloud)
00081   void cloudCb(const boost::shared_ptr<const sensor_msgs::PointCloud2>& cloud)
00082   {
00083     boost::mutex::scoped_lock lock(cloud_mutex_);
00084     cloud_msg_ = cloud;
00085     cloud_condition_.notify_all();
00086   }
00087 
00088 
00089 
00090   bool detect_wall (stereo_wall_detection::DetectWall::Request &req, stereo_wall_detection::DetectWall::Response &resp)
00091   {
00092     ros::Time start_time = ros::Time::now();
00093 
00094     // wait for new pointcloud
00095     boost::mutex::scoped_lock lock(cloud_mutex_);
00096     cloud_condition_.wait(lock);
00097     bool cloud_found = false;
00098     while (ros::ok() && !cloud_found){
00099       // check for timeout
00100       if (ros::Time::now() > start_time + ros::Duration(10.0)){
00101         ROS_ERROR("Did not receive a pointcloud in 10 seconds");
00102         return false;
00103       }
00104 
00105       // check if this is a good pointcloud
00106       if (cloud_msg_->header.stamp > start_time){
00107         unsigned count = 0;
00108         for (unsigned i=0; i<cloud_msg_->height * cloud_msg_->width; i++){
00109           if (!std::isnan(cloud_msg_->data[i])){
00110             count++;
00111           }
00112         }
00113         if (count > 30000)
00114           cloud_found = true;
00115         else
00116           ROS_INFO("Received a cloud, but it only had %d points", count);
00117       }
00118       else
00119         ROS_INFO("Received a cloud, but the cloud is still %f seconds before start time", (start_time - cloud_msg_->header.stamp).toSec());
00120 
00121       // wait for another cloud
00122       if (!cloud_found)     
00123         cloud_condition_.wait(lock);
00124     }
00125     ROS_INFO("point cloud received");
00126 
00127 
00128     double threshold;
00129     nh_.param<double>("distance_threshold", threshold, 0.01);
00130 
00131     int tmp_points;
00132     // minimum number of inliers; a good detection appears to have over 
00133     // 100,000 inliers
00134     nh_.param<int>("minimum_points", tmp_points, 20000);
00135     size_t min_points = tmp_points;
00136 
00137     // find plane in pointcloud
00138     pcl::PointCloud<pcl::PointXYZ> cloud;
00139     pcl::fromROSMsg(*cloud_msg_, cloud);
00140     pcl::ModelCoefficients::Ptr coefficients (new pcl::ModelCoefficients);
00141     pcl::PointIndices::Ptr inliers (new pcl::PointIndices);
00142     pcl::SACSegmentation<pcl::PointXYZ> seg;
00143     seg.setOptimizeCoefficients (true);
00144     seg.setModelType (pcl::SACMODEL_PLANE);
00145     seg.setMethodType (pcl::SAC_RANSAC);
00146     seg.setDistanceThreshold (threshold);
00147     seg.setInputCloud (cloud.makeShared ());
00148     seg.segment (*inliers, *coefficients);
00149     if (inliers->indices.size () == 0) {
00150       ROS_ERROR ("Could not estimate a planar model for the given dataset.");
00151       return false;
00152     }
00153 
00154     // check for minimum number of inliers in plane; if we have too few, our
00155     // detection is bad and we should return an error
00156     if( inliers->indices.size() < min_points ) {
00157        ROS_ERROR("Too few inliers in deteted plane: %zd", inliers->indices.size());
00158        return false;
00159     }
00160 
00161     pcl::copyPointCloud(cloud, *inliers, cloud); // add publisher here to see resulting point cloud.
00162     Eigen::Vector4f centroid;
00163     pcl::compute3DCentroid(cloud, centroid);
00164 
00165     // publish cloud with detected points for debugging
00166     if( plane_points_.getNumSubscribers() > 0 ) {
00167       sensor_msgs::PointCloud2 plane_msg;
00168       pcl::toROSMsg(cloud, plane_msg); 
00169       plane_points_.publish(plane_msg);
00170     }
00171 
00172     geometry_msgs::Vector3 normal;
00173     normal.x = coefficients->values[0];
00174     normal.y = coefficients->values[1];
00175     normal.z = coefficients->values[2];
00176 
00177     if( normal.z < 0 ) {
00178       // Normal points towards camera; reverse it
00179       ROS_WARN("Wall Normal points towards camera frame: %s", 
00180         cloud_msg_->header.frame_id.c_str());
00181       normal.x = -normal.x;
00182       normal.y = -normal.y;
00183       normal.z = -normal.z;
00184     } else {
00185       ROS_WARN("Wall normal points away from camera frame: %s", 
00186         cloud_msg_->header.frame_id.c_str());
00187     }
00188 
00189     resp.wall_norm.header = cloud_msg_->header;
00190     resp.wall_norm.vector = normal;
00191 
00192     resp.wall_point.header = cloud_msg_->header;
00193     resp.wall_point.point.x = centroid[0];
00194     resp.wall_point.point.y = centroid[1];
00195     resp.wall_point.point.z = centroid[2];
00196 
00197 
00198     // publish Marker vector of wall normal for debugging
00199     if( plane_marker_.getNumSubscribers() > 0 ) {
00200       visualization_msgs::Marker marker;
00201 
00202       // set up marker
00203       marker.header = cloud_msg_->header;
00204       marker.id = 0;
00205       marker.type =   visualization_msgs::Marker::ARROW;
00206       marker.action = visualization_msgs::Marker::ADD; // add/modify
00207 
00208       // visible, red marker
00209       marker.color.a = 1.0;
00210       marker.color.r = 1.0;
00211       marker.color.g = 0.0;
00212       marker.color.b = 0.0;
00213 
00214       geometry_msgs::Point end;   // vector end
00215       end.x = resp.wall_point.point.x + resp.wall_norm.vector.x;
00216       end.y = resp.wall_point.point.y + resp.wall_norm.vector.y;
00217       end.z = resp.wall_point.point.z + resp.wall_norm.vector.z;
00218 
00219       marker.points.push_back(resp.wall_point.point);
00220       marker.points.push_back(end);
00221 
00222       marker.scale.x = 0.05;
00223       marker.scale.y = 0.1;
00224       //marker.scale.z = 0.1;
00225 
00226       plane_marker_.publish(marker);
00227     }
00228 
00229     ROS_INFO("Found wall at %f %f %f with normal: %f %f %f in frame %s",
00230              resp.wall_point.point.x, resp.wall_point.point.y, resp.wall_point.point.z,
00231              resp.wall_norm.vector.x, resp.wall_norm.vector.y, resp.wall_norm.vector.z, 
00232              cloud_msg_->header.frame_id.c_str());
00233 
00234     return true;
00235   }
00236 
00237 private:
00238   ros::NodeHandle nh_;
00239   ros::ServiceServer serv_;
00240   ros::Publisher plane_points_;
00241   ros::Publisher plane_marker_;
00242   ros::Subscriber cloud_sub_;
00243 
00244   sensor_msgs::PointCloud2ConstPtr cloud_msg_;
00245   boost::condition cloud_condition_;
00246   boost::mutex cloud_mutex_;
00247 };
00248 
00249 
00250 
00251 int main (int argc, char** argv)
00252 {
00253   ros::init (argc, argv, "wall_extractor");
00254 
00255   PlanarFit p;
00256   ros::MultiThreadedSpinner spinner(2);  // extra thread so we can receive cloud messages while in the service call
00257   spinner.spin();
00258 
00259   return (0);
00260 }
00261 


stereo_wall_detection
Author(s): Radu Bogdan Rusu
autogenerated on Mon Dec 2 2013 13:20:44