Chrono::ROS is an optional module that enables direct integration of Chrono with the Robot Operating System (ROS).

Features

The ROS module allows users to interface a ROS 2-based autonomy stack with autonomous agents in Chrono.

For more detail, read the Chrono::ROS section of the reference manual.

Requirements

To build and run applications based on this module, the following are required:
- A distribution for Linux (any ROS2 distribution) or Windows 11 (requires ROS2 Lyrical).
- Available shared memory (/dev/shm) sized for the bridge's channel.
  - The simulation and the ROS subprocess communicate over a shared-memory channel. Its default capacity is 128 MiB for simulation-to-ROS (publishing) traffic plus 32 MiB for ROS-to-simulation (received-command) traffic.
  - Sizing: peak sim->node usage is roughly (number of actively-subscribed large topics) × (per-message size). Handlers skip publishing a topic that has no subscriber, and the subprocess drains the channel continuously, so frames rarely accumulate beyond one or two per topic. A 4K RGBA8 image is ~31.6 MiB, so the 128 MiB default holds about four such frames in flight — ample in practice. If ChROSBridge::GetDroppedOutboundCount() grows during a run, a subscriber was too slow to keep up and the channel filled momentarily.
  - Override the capacities with ChROSManager::SetChannelCapacity(sim_to_node_bytes, node_to_sim_bytes) — both directions are set together, and it must be called before Initialize(). Raise them for many simultaneous high-bandwidth streams or very large custom topics; lower them on memory-constrained systems. /dev/shm must exceed the configured total plus some slack.
- All current ROS 2 distributions and middleware (rmw) variants are supported; ROS 1 is not.
- A ROS 2 installation (see docs.ros.org for instructions). Docker is recommended; a Docker image with Chrono::ROS built is available here.
  - When using Docker, override the default shm_size (often 64 MB) so it exceeds the configured channel total; shm_size: 256mb covers the default capacity.
- NOTE: All ROS 2 packages required by Chrono::ROS are included in the base ROS 2 installation.

Optional Dependencies

Some features (detailed in the reference manual) are conditionally built based on some optional dependencies. These dependencies include:
- chrono_ros_interfaces
To build URDF support for Chrono::ROS, you will also need to enable the Chrono::Parsers module.

NOTE: If you enable Chrono::Parsers with URDF support and you're using a ROS 2 distribution newer than Iron, ensure the urdfdom_DIR is set not to the ROS 2 installation. The ChParserURDF class uses a newer version of urdfdom.

Building instructions

To build Chrono::ROS, after installing the above dependencies, ensure you have sourced your ROS 2 installation (e.g. source /opt/ros/humble/setup.bash).
Repeat the instructions for the full installation.
Set CH_ENABLE_MODULE_ROS to 'on' in CMake config arguments or the GUI equivalent.
As mentioned above, to enable URDF support, you must also enable the Chrono::Parsers module.
Press 'Configure' again, then 'Generate', and proceed as usual in the installation instructions.

How to use it

Consult the reference manual.
Look at the API section of this module for documentation about classes and functions.
Look at the C++ and Python source of demos to learn how to use the functions of this module.