ROS 2 integration overview#
Gazebo can be integrated within a ROS 2 system. Let’s start describing the different types of integrations that you can achieve between Gazebo and ROS.
Use ROS to launch Gazebo: ROS prescribes a specific way to launch all the pieces needed in your system. There’s a dedicated launch mechanism to orchestrate the launch of all your components and many tooling around it. Gazebo can be launched in this way.
Use ROS to interact with Gazebo topics via the
ros_gzbridge: Once Gazebo is up and running, it’s very common to communicate with the simulation. A common way to perform this communication is via topics. Gazebo has its own middleware, Gazebo Transport, that exposes a set of topics and services quite similar to ROS. Theros_gzbridge allows you to create a bridge between Gazebo and your ROS system, that translates between Gazebo Transport and ROS 2 as needed.Use ROS to spawn a Gazebo model: Gazebo worlds can include models that are loaded at startup. However, sometimes you need to spawn models at runtime. This task can be performed using ROS 2.
Requirements#
Please follow the Install Gazebo and ROS document before starting this tutorial. A working installation of ROS 2 and Gazebo is required to go further.
Composition#
If you inspect the parameters of the launch files mentioned in the next
tutorials, you’ll notice that we have included in most cases a parameter named
use_composition. When that parameter is set to True, the associated ROS
node will be included within a ROS container. When this happens all the nodes
live within the same process and can leverage intraprocess communication.
Our recommendation is to always set the use_composition parameter to True.
That way, the communication between Gazebo and the bridge will be intraprocess.
If your ROS nodes are also written as composable nodes, make sure that they are
launched with the container_node_name parameter matching the container name
including Gazebo and the bridge.
You can learn more about ROS composition in this tutorial.