无法解决PCL柱面检测引起的错误

Question

我使用PointCloudLibrary(PCL(来执行列检测。执行气缸检测的程序如下(与PCL教程几乎相同(。

#include <pcl/ModelCoefficients.h>
#include <pcl/io/pcd_io.h>
#include <pcl/point_types.h>
#include <pcl/filters/extract_indices.h>
#include <pcl/filters/passthrough.h>
#include <pcl/features/normal_3d.h>
#include <pcl/sample_consensus/method_types.h>
#include <pcl/sample_consensus/model_types.h>
#include <pcl/segmentation/sac_segmentation.h>
typedef pcl::PointXYZ PointT;
int
main (int argc, char** argv)
{
std::string filename = "inputfile.pcd";
// All the objects needed
pcl::PCDReader reader;
pcl::PassThrough<PointT> pass;
pcl::NormalEstimation<PointT, pcl::Normal> ne;
pcl::SACSegmentationFromNormals<PointT, pcl::Normal> seg; 
pcl::PCDWriter writer;
pcl::ExtractIndices<PointT> extract;
pcl::ExtractIndices<pcl::Normal> extract_normals;
pcl::search::KdTree<PointT>::Ptr tree (new pcl::search::KdTree<PointT> ());
// Datasets
pcl::PointCloud<PointT>::Ptr cloud (new pcl::PointCloud<PointT>);
pcl::PointCloud<PointT>::Ptr cloud_filtered (new pcl::PointCloud<PointT>);
pcl::PointCloud<pcl::Normal>::Ptr cloud_normals (new pcl::PointCloud<pcl::Normal>);
pcl::PointCloud<PointT>::Ptr cloud_filtered2 (new pcl::PointCloud<PointT>);
pcl::PointCloud<pcl::Normal>::Ptr cloud_normals2 (new pcl::PointCloud<pcl::Normal>);
pcl::ModelCoefficients::Ptr coefficients_plane (new pcl::ModelCoefficients), 
coefficients_cylinder (new pcl::ModelCoefficients);
pcl::PointIndices::Ptr inliers_plane (new pcl::PointIndices), inliers_cylinder (new 
pcl::PointIndices);
// Read in the cloud data
reader.read (filename, *cloud);
std::cerr << "PointCloud has: " << cloud->points.size () << " data points." << std::endl;
// Build a passthrough filter to remove spurious NaNs
pass.setInputCloud (cloud);
pass.setFilterFieldName ("z");
pass.setFilterLimits (0, 1.5);
pass.filter (*cloud_filtered);
std::cerr << "PointCloud after filtering has: " << cloud_filtered->points.size () << " 
data points." << std::endl;
// Estimate point normals
ne.setSearchMethod (tree);
ne.setInputCloud (cloud_filtered);
ne.setKSearch (50);
ne.compute (*cloud_normals);
// Create the segmentation object for the planar model and set all the parameters
seg.setOptimizeCoefficients (true);
seg.setModelType (pcl::SACMODEL_NORMAL_PLANE);
seg.setNormalDistanceWeight (0.1);
seg.setMethodType (pcl::SAC_RANSAC);
seg.setMaxIterations (100);
seg.setDistanceThreshold (0.03);
seg.setInputCloud (cloud_filtered);
seg.setInputNormals (cloud_normals);
// Obtain the plane inliers and coefficients
seg.segment (*inliers_plane, *coefficients_plane);
std::cerr << "Plane coefficients: " << *coefficients_plane << std::endl;
// Extract the planar inliers from the input cloud
extract.setInputCloud (cloud_filtered);
extract.setIndices (inliers_plane);
extract.setNegative (false);
// Write the planar inliers to disk
pcl::PointCloud<PointT>::Ptr cloud_plane (new pcl::PointCloud<PointT> ());
extract.filter (*cloud_plane);
std::cerr << "PointCloud representing the planar component: " << cloud_plane->points.size 
() << " data points." << std::endl;
writer.write (filename, *cloud_plane, false);
// Remove the planar inliers, extract the rest
extract.setNegative (true);
extract.filter (*cloud_filtered2);
extract_normals.setNegative (true);
extract_normals.setInputCloud (cloud_normals);
extract_normals.setIndices (inliers_plane);
extract_normals.filter (*cloud_normals2);
// Create the segmentation object for cylinder segmentation and set all the parameters
seg.setOptimizeCoefficients (true);
seg.setModelType (pcl::SACMODEL_CYLINDER);
seg.setMethodType (pcl::SAC_RANSAC);
seg.setNormalDistanceWeight (0.1);
seg.setMaxIterations (10000);
seg.setDistanceThreshold (0.05);
seg.setRadiusLimits (0, 0.1);
seg.setInputCloud (cloud_filtered2);
seg.setInputNormals (cloud_normals2);
// Obtain the cylinder inliers and coefficients
seg.segment (*inliers_cylinder, *coefficients_cylinder);
std::cerr << "Cylinder coefficients: " << *coefficients_cylinder << std::endl;
// Write the cylinder inliers to disk
extract.setInputCloud (cloud_filtered2);
extract.setIndices (inliers_cylinder);
extract.setNegative (false);
pcl::PointCloud<PointT>::Ptr cloud_cylinder (new pcl::PointCloud<PointT> ());
extract.filter (*cloud_cylinder);
if (cloud_cylinder->points.empty ()) 
std::cerr << "Can't find the cylindrical component." << std::endl;
else
{
std::cerr << "PointCloud representing the cylindrical component: " << cloud_cylinder- 
>points.size () << " data points." << std::endl;
writer.write (filename, *cloud_cylinder, false);
}
return (0);
}

然后，对于一些点云文件，我得到了以下错误。当然，在输入文件中可能存在点云，但我找不到它们。显示了输入文件中点云的数量，所以我认为我可以输入数据，但由于某种原因，我无法获得圆柱体参数。但是，由于某些原因，我无法获得圆柱体参数。

PointCloud has: 1042 data points.
PointCloud after filtering has: 0 data points.
[pcl::NormalEstimation::compute] input_ is empty! 
[pcl::SampleConsensusModel::getSamples] Can not select 0 unique points out of 0!
[pcl::RandomSampleConsensus::computeModel] No samples could be selected!
[pcl::SACSegmentationFromNormals::segment] Error segmenting the model! No solution found.
Plane coefficients: header: 
seq: 0 stamp: 0 frame_id: 
values[]
PointCloud representing the planar component: 0 data points.
terminate called after throwing an instance of 'pcl::IOException'
what():  : [pcl::PCDWriter::writeASCII] Input point cloud has no data!
Aborted (core dumped)

Answer 1

在对代码中的阈值进行了多次修改后，我们能够解决这个问题。