Repository Summary

Checkout URI https://github.com/peterweissig/ros_pcdfilter.git
VCS Type git
VCS Version master
Last Updated 2020-06-09
Dev Status MAINTAINED
CI status No Continuous Integration
Released UNRELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Packages

Name Version
pcdfilter_pa 1.2.0

README

ProAut Pointcloud Filter

Introduction

This package was designed to remove simple geometric shapes from pointclouds. E.g. A cube or a sphere. Several of these filters can be applied to a pointcloud in one shot. For more details on the types of filters and their parameters see Filters.

This package includes a full node and a ros interface for one's own node. For more details about the node, like topic names and parameters, see Node.

The package can handle three different input types of pointclouds: * sensor_msgs/PointCloud2 (this is also the output type) * sensor_msgs/PointCloud * sensor_msgs/LaserScan

Additionaly the input data can be throttled to reduce the cpu load.

Node

rosrun pcdfilter_pa pcdfilter_pa_node
roslaunch pcdfilter_pa pcdfilter_pa.launch

Input and Output Topics

Topic Name Type Description
"~/in_cloud" sensor_msgs/PointCloud2 Input as new pointcloud type.
"~/in_cloud_old" sensor_msgs/PointCloud Input as old pointloud type. Will be converted to new pointcloud type.
"~/in_laser" sensor_msgs/LaserScan Input as single laser scan. Will be converted to new pointcloud type by package "laser_geometry".
"~/out_cloud" sensor_msgs/PointCloud2 Output of filtering node.

All topics can be remapped using parameters (see below).

Services

Service Name Type Description
"~/filter" pcdfilter_pa/PcdFilterPaCloud Forced filtering via service call. No throttling is done and input/output cloud is part of service message.
"~/add_filters" pcdfilter_pa/PcdFilterPaFilter Adding new filters. Old filters are kept.
"~/change_filters" pcdfilter_pa/PcdFilterPaFilter Adding new filters, but removing all old filters before adding.
"~/enable" std_srvs/Empty Disables this node. This also disconnects the node from all input messages.
"~/disable" std_srvs/Empty Enables this node.

Parameters

Filter

Parameter Name Type Description
"~/filters" vector of strings All pointcloud filters as an array of strings.

general settings

Parameter Name Type Description
"~/skip_count" integer Input throttling. Number of skipped messages after each processed message.
"~/skip_time" double Input throttling. Time intervall in seconds. After each processed message, this intervall starts and all input messages will be skipped.
"~/tf_lookup_time" double Maximum time in seconds for waiting for a specific TF transform.
"~/buffer_pointcloud" bool Flag for buffering the last received pointcloud. This can be used to test different filters without resending the some pointcloud.
"~/debugging" bool Flag for enabling extented output.
"~/enabled" bool Flag for setting start up behaviour. Indicates if node is filtering at startup, or not.

laser

Parameter Name Type Description
"~/laser_nan_replacement_value" double If a nan-value is represented within the laser scan, it might indicate "no obstacle within range". Therefore this parameters will replace those values with a fixed number.

topics and services

Parameter Name Type Description
"~/topic_in_cloud" string Name of input topic for new pointclouds.
"~/topic_in_cloud_old" string Name of input topic for old pointclouds.
"~/topic_in_laser" string Name of input topic for laser scans.
"~/topic_out_cloud" string Name of output topic for filtered pointcloud.

See also this config file. It contains all parameters and their default value.

Filter

Definition

This is the definition of every single filter as a string.

[<inversion>]<type> <separator> <dimensions> <tf> [<tf_offset>] [<tf2> [<tf2_offset>]] [# <comment>]

inversion (optional)

Inversion Description
"" (none) normal behaviour; points within the volume will be filtered out; all points outside will be kept
"!" reversed behaviour; points within the volume will be kept; all points outside will be filtered out

type

Type Description Nr Parameters Nr TF ids
"cube" specified by its sidelength 1 parameter 1 TF
"sphere" specified by its radius 1 parameter 1 TF
"block" cuboid specified by its three sidelengths in x,y and z direction 3 parameters 1 TF
"cylinder" specified by its radius and its height 2 parameters 1 TF
"link" cylinder centered around the two given tfs; specified by its radius and its overshoot 2 parameters 2 TF
"cone" cone headed at fist tf and pointing to second tf; specified by its height and its ratio (radius/height) 2 parameters 2 TF

separator

Seperator Description
":" current filter is required; if some tf is missing the whole filtering is aborted and no output pointcloud is generated
"?" current filter may be skipped; if some tf is missing then the current filter is not applied; but in any case the whole filtering and output process is continued

To control how long the filter should wait for the necessary tf there exists a parameter "~/tf_lookup_time" - see also Node.

dimensions

Number of dimensions depends on the type of the current filter(see above). At least one dimension is always needed, e.g. for a cube. Three dimensions must be set for a cuboid. \ Each dimension is a single number seperated by spaces.

tf

ROS frame id for the filtered objects.

tf_offset (optional)

This allows for an additional offset relative to the given frame id. Order of parameters: x y z qx qy qz qw

Missing parameters will be set to "0". If qw is not set then it will be set to sqrt(1 - qx^2 - qy^2 - qz^2)

tf2 and tf2_offset (optional)

Only valid for type "link" and "cone".
For description see above (tf and tf_offset).

comment

Every character following '#' is ignored. This can be used to give a short comment.

Examples

cube: 3 base_footprint

Filters every point within the following cube - the cube is removed from the pointcloud. \ The sidelength is 3 [meters]. \ The center is aligned with TF frame "base_footprint". \ Corners will be at [+/-1.5 , +/- 1.5, +/- 1.5].

!sphere: 2.3 map

Only points within sphere will stay.
The center of sphere is aligned with TF frame "map".
The radius is 2.3 [meters] and the diameter is 4.6 [meters].

block: 1 2 3 base_link 0.5 1 1.5

Removes every point within the cuboid.
One corner of the cuboid is at center of TF frame "base_link".
This is due to the additional offset of [0.5, 1 1.5].
Two opposite corners are at [0, 0, 0] and [1, 2, 3].

link: 0.2 0 arm_link1 arm_link2

Removes every point within the cylinder, which is attached to both TF frames. \ The center of the top and bottom surface is exactly at origin of one frame (zero overshoot). \ The radius is 0.2 [meters]. \ The height depends only the relative position of the two frames. \ Also the orientation of the cylinder is not fixed to any frame.

!cone: 10 1 laser pan_tilt_tilt_link

Removes every point outside the cone. \ The top of cone will be at the origin of the TF frame "laser" and the centerline will go straight through the origin of the TF frame "pan_tilt_tilt_link". \ The height is 10 [meters]. \ The angle at the top is 90 degrees (ratio of radius to height is 1:1).

Source code at github

https://github.com/TUC-ProAut/ros_pcdfilter

https://github.com/TUC-ProAut/ros_parameter

ROS packages

ros-kinetic-pcdfilter-pa

ROS Build-Status and Documentation

ROS-Distribution Build-Status Documentation
Indigo EOL April 2019 docs.ros.org/indigo
Jade EOL May 2017 docs.ros.org/jade
Kinetic Build Status docs.ros.org/kinetic
Lunar EOL May 2019 docs.ros.org/lunar
Melodic upcoming docs.ros.org/melodic

CONTRIBUTING

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