elevation_map_loader#

Purpose#

This package provides elevation map for compare_map_segmentation.

Inner-workings / Algorithms#

Generate elevation_map from subscribed pointcloud_map and vector_map and publish it. Save the generated elevation_map locally and load it from next time.

The elevation value of each cell is the average value of z of the points of the lowest cluster.
Cells with No elevation value can be inpainted using the values of neighboring cells.

Inputs / Outputs#

Input#

Name	Type	Description
`input/pointcloud_map`	`sensor_msgs::msg::PointCloud2`	The point cloud map
`input/vector_map`	`autoware_auto_mapping_msgs::msg::HADMapBin`	(Optional) The binary data of lanelet2 map
`input/pointcloud_map_metadata`	`autoware_map_msgs::msg::PointCloudMapMetaData`	(Optional) The metadata of point cloud map

Output#

Name	Type	Description
`output/elevation_map`	`grid_map_msgs::msg::GridMap`	The elevation map
`output/elevation_map_cloud`	`sensor_msgs::msg::PointCloud2`	(Optional) The point cloud generated from the value of elevation map

Service#

Name	Type	Description
`service/get_selected_pcd_map`	`autoware_map_msgs::srv::GetSelectedPointCloudMap`	(Optional) service to request point cloud map. If pointcloud_map_loader uses selected pointcloud map loading via ROS 2 service, use this.

Parameters#

Node parameters#

Name	Type	Description	Default value
map_layer_name	std::string	elevation_map layer name	elevation
param_file_path	std::string	GridMap parameters config	path_default
elevation_map_directory	std::string	elevation_map file (bag2)	path_default
map_frame	std::string	map_frame when loading elevation_map file	map
use_inpaint	bool	Whether to inpaint empty cells	true
inpaint_radius	float	Radius of a circular neighborhood of each point inpainted that is considered by the algorithm [m]	0.3
use_elevation_map_cloud_publisher	bool	Whether to publish `output/elevation_map_cloud`	false
use_lane_filter	bool	Whether to filter elevation_map with vector_map	false
lane_margin	float	Margin distance from the lane polygon of the area to be included in the inpainting mask [m]. Used only when use_lane_filter=True.	0.0
use_sequential_load	bool	Whether to get point cloud map by service	false
sequential_map_load_num	int	The number of point cloud maps to load at once (only used when use_sequential_load is set true). This should not be larger than number of all point cloud map cells.	1

GridMap parameters#

The parameters are described on config/elevation_map_parameters.yaml.

General parameters#

Name	Type	Description	Default value
pcl_grid_map_extraction/num_processing_threads	int	Number of threads for processing grid map cells. Filtering of the raw input point cloud is not parallelized.	12

Grid map parameters#

See: https://github.com/ANYbotics/grid_map/tree/ros2/grid_map_pcl

Resulting grid map parameters.

Name	Type	Description	Default value
pcl_grid_map_extraction/grid_map/min_num_points_per_cell	int	Minimum number of points in the point cloud that have to fall within any of the grid map cells. Otherwise the cell elevation will be set to NaN.	3
pcl_grid_map_extraction/grid_map/resolution	float	Resolution of the grid map. Width and length are computed automatically.	0.3
pcl_grid_map_extraction/grid_map/height_type	int	The parameter that determine the elevation of a cell `0: Smallest value among the average values of each cluster`, `1: Mean value of the cluster with the most points`	1
pcl_grid_map_extraction/grid_map/height_thresh	float	Height range from the smallest cluster (Only for height_type 1)	1.0

Point Cloud Pre-processing Parameters#

Rigid body transform parameters#

Rigid body transform that is applied to the point cloud before computing elevation.

Name	Type	Description	Default value
pcl_grid_map_extraction/cloud_transform/translation	float	Translation (xyz) that is applied to the input point cloud before computing elevation.	0.0
pcl_grid_map_extraction/cloud_transform/rotation	float	Rotation (intrinsic rotation, convention X-Y'-Z'') that is applied to the input point cloud before computing elevation.	0.0

Cluster extraction parameters#

Cluster extraction is based on pcl algorithms. See https://pointclouds.org/documentation/tutorials/cluster_extraction.html for more details.

Name	Type	Description	Default value
pcl_grid_map_extraction/cluster_extraction/cluster_tolerance	float	Distance between points below which they will still be considered part of one cluster.	0.2
pcl_grid_map_extraction/cluster_extraction/min_num_points	int	Min number of points that a cluster needs to have (otherwise it will be discarded).	3
pcl_grid_map_extraction/cluster_extraction/max_num_points	int	Max number of points that a cluster can have (otherwise it will be discarded).	1000000

Outlier removal parameters#

See https://pointclouds.org/documentation/tutorials/statistical_outlier.html for more explanation on outlier removal.

Name	Type	Description	Default value
pcl_grid_map_extraction/outlier_removal/is_remove_outliers	float	Whether to perform statistical outlier removal.	false
pcl_grid_map_extraction/outlier_removal/mean_K	float	Number of neighbors to analyze for estimating statistics of a point.	10
pcl_grid_map_extraction/outlier_removal/stddev_threshold	float	Number of standard deviations under which points are considered to be inliers.	1.0

Subsampling parameters#

See https://pointclouds.org/documentation/tutorials/voxel_grid.html for more explanation on point cloud downsampling.

Name	Type	Description	Default value
pcl_grid_map_extraction/downsampling/is_downsample_cloud	bool	Whether to perform downsampling or not.	false
pcl_grid_map_extraction/downsampling/voxel_size	float	Voxel sizes (xyz) in meters.	0.02