With the ROS electric release, the orocos_toolchain_ros stack has been split up into 5 different stacks, and the rtt_ros_integration package has become a stack. Check out orocos_toolchain_ros/electric for more information.
Contents
Installation
Ubuntu
sudo aptitude install ros-electric-rtt-ros-integration
Compiling from source
Clone the repository using
git clone http://git.mech.kuleuven.be/robotics/rtt_ros_integration.git rosmake rtt_ros_integration
Upgrade from diamondback
Upgrading from diamondback involves changes of package names and removing the old libraries. A script automating this upgrade is available in the new rtt_rosnode package. To run it:
rosrun rtt_rosnode rtt-upgrade-2.5 <package_dir>
Using ROS messages in Orocos components
To set up communication between RTT and ROS:
You need to generate an Orocos typekit for the ROS messages you want to use. Here is the option you have to use an existing typekit, or to generate yours :
rtt_std_msgs is such a typekit for std_msgs - other typekits for the most commonly used ROS messages are available in the rtt_common_msgs and rtt_ros_comm stacks.
other typekits can be generated using the rtt_create_msgs script, available in rtt_rosnode. Lets say you have a ROS package named MyPkg in which a custom message is defined. To create the typekit for MyPkg:
rosrun rtt_rosnode create_rtt_msgs MyPkg
This will create the package rtt_MyPkg with typekits for your custom ROS messages.
Use the typekit in your C++ code
Imagine the Orocos package in which you want to add the message is OrocosPkg, and you want to use the messages from you MyPkg package.
You have to edit OrocosPkg/manifest.xml to add the following line :
<depend package="rtt_MyPkg"/>
In doing so, you will depend indirectly on rtt_rosnode.
In order to use the messages defined in MyPkg in your OROCOS component, include the message headers to your OrocosPkg C++ code :
#include <MyPkg/typekit/MsgName.h>
Then, you may fill in or read out the ROS Message in your components.
Creating and deploying Orocos components
First, you create an Orocos component package, instead of a plain ROS package. Once compiled, deploying OROCOS components can be done either using .xml or .ops file formats.
Creating an Orocos component
See the Orocos Component Builder's Manual, but in short:
rosrun ocl orocreate-pkg my_component_pkg component cd my_component_pkg rosmake
A template/dummy component will be built. Now proceed deploying it.
.ops deployment script
Start the Orocos deployer with
rosrun ocl deployer-gnulinux [-s scriptname.ops]
There you get a prompt where you can
- Import component definitions using the Orocos package name (directory name) :
import("rtt_rosnode") // makes this process a ROS node
import("my_component_pkg")
loadComponent("YourComponentName","My_component_pkg")
// See DeploymentComponent Manual for creating a component using 'loadComponent'- Stream your component's data to a ROS topic:
stream("YourComponentName.YourRTTPortName", ros.topic("/topic_name"))
.xml deployment script
Start the Orocos deployer with
rosrun ocl deployer-gnulinux -s xmlfile.xml
Import the Orocos component definitions and add a ConnPolicy structure to your RTT deployer configuration
<simple name="Import" type="string"><value>rtt_rosnode</value></simple> <simple name="Import" type="string"><value>my_component_pkg</value></simple> <struct name="ROSConMsg" type="ConnPolicy"> <simple name="transport" type="short"><value>3</value></simple><!-- 3 means ROS --/> <simple name="name_id" type="string"><value>topic_name</value></simple> </struct>
Link you RTT Components Port to the ConnPolicy structure you just set up:
<struct name="Ports" type="PropertyBag"> <simple name="YourRTTPortName" type="string"><value> RosConMsg </value></simple> </struct>
Done, your RTT component can now connects its ports to ROS topics! To test, start a ROS::master, deploy your component and investigate the published nodes with rxgraph
Example Application
The rtt_ros_integration_example package contains an example RTT component to demonstrate the use of this package.