Bridge communication between ROS 1 and Ignition Transport

This package provides a network bridge which enables the exchange of messages between ROS 1 and Ignition Transport.

The bridge is currently implemented in C++. At this point there's no support for service calls.Its support is limited to only the following message types:

ROS 1 type	Ignition Transport type
std_msgs/Header	ignition::msgs::Header
std_msgs/String	ignition::msgs::StringMsg
geometry_msgs/Quaternion	ignition::msgs::Quaternion
geometry_msgs/Vector3	ignition::msgs::Vector3d
geometry_msgs/Point	ignition::msgs::Vector3d
geometry_msgs/Pose	ignition::msgs::Pose
geometry_msgs/PoseStamped	ignition::msgs::Pose
geometry_msgs/Transform	ignition::msgs::Pose
geometry_msgs/TransformStamped	ignition::msgs::Pose
sensor_msgs/Imu	ignition::msgs::IMU
sensor_msgs/Image	ignition::msgs::Image
sensor_msgs/LaserScan	ignition::msgs::LaserScan
sensor_msgs/MagneticField	ignition::msgs::Magnetometer

Run parameter_bridge -h for instructions.

Prerequisites

For all examples you need to source the environment of the install space where the bridge was built or unpacked to. Additionally you will need to either source the ROS 1 environment or at least set the ROS_MASTER_URI and run a roscore.

The following ROS 1 packages are required to build and use the bridge:

• catkin
• geometry_msgs
• roscpp
• roslaunch (for roscore executable)
• rosmsg
• sensor_msgs
• std_msgs

To run the following examples you will also need these ROS 1 packages:

• rosbash (for rosrun executable)
• roscpp_tutorials
• rostopic
• rqt_image_view

The following Ignition dependencies are also needed:

• libignition-msgs3-dev
• libignition-transport6-dev

Building the bridge from source

Before continuing you should have the prerequisites for building the bridge from source installed.

Here are the steps (for Linux and OSX; you probably don't have ROS 1 installed on Windows).

1. Create a catkin workspace:

# Setup the workspace
mkdir -p ~/bridge_ws/src
cd ~/bridge_ws/src

# Download needed software
git clone https://github.com/osrf/ros1_ign_bridge.git

2. Build the workspace:

# Source ROS distro's setup.bash
source /opt/ros/melodic/setup.bash

# Build and install into workspace
cd ~/bridge_ws/
catkin_make install

Example 1a: Ignition Transport talker and ROS 1 listener

First we start a ROS 1 roscore:

# Shell A:
. /opt/ros/melodic/setup.bash
roscore

Then we start the parameter bridge which will watch the specified topics.

# Shell B:
. ~/bridge_ws/install/setup.bash
rosrun ros1_ign_bridge parameter_bridge /chatter@std_msgs/[email protected]

Now we start the ROS 1 listener.

# Shell C:
. /opt/ros/melodic/setup.bash
rostopic echo /chatter

Now we start the Ignition Transport talker.

# Shell D:
ign topic pub -t /chatter -m ignition.msgs.StringMsg -p 'data:"Hello"'

Example 1b: ROS 1 talker and Ignition Transport listener

First we start a ROS 1 roscore:

# Shell A:
. /opt/ros/melodic/setup.bash
roscore

Then we start the parameter bridge which will watch the specified topics.

# Shell B:
. ~/bridge_ws/install/setup.bash
rosrun ros1_ign_bridge parameter_bridge /chatter@std_msgs/[email protected]

Now we start the Ignition Transport listener.

# Shell C:
ign topic -e -t /chatter

Now we start the ROS 1 talker.

# Shell D:
. /opt/ros/melodic/setup.bash
rostopic pub /chatter std_msgs/String "data: 'Hi'" --once

Example 2: Run the bridge and exchange images

In this example, we're going to generate Ignition Transport images using Gazebo, that will be converted into ROS 1 images, and visualized with rqt_viewer.

First we start a ROS 1 roscore:

# Shell A:
. /opt/ros/melodic/setup.bash
roscore

Then we start Gazebo.

# Shell B:
gazebo

Once Gazebo is running, click on the Insert tab, and then, insert a Camera object into the scene. Now, let's see the topic where the camera images are published.

# Shell C:
ign topic -l | grep image
/default/camera/link/camera/image

Then we start the parameter bridge with the previous topic.

# Shell D:
. ~/bridge_ws/install/setup.bash
rosrun ros1_ign_bridge parameter_bridge /default/camera/link/camera/image@sensor_msgs/[email protected]

Now we start the ROS 1 GUI:

# Shell E:
. /opt/ros/melodic/setup.bash
rqt_image_view /default/camera/link/camera/image

You should see the current images in rqt_image_view which are coming from Gazebo (published as Ignition Msgs over Ignition Transport).

The screenshot shows all the shell windows and their expected content (it was taken using ROS Kinetic):