Skip to content

ROS 2 + MoveIt 2¤

The current ROS-based planning back-end for compas_fab. Uses ROS 2 Jazzy (LTS, 2024–2029), MoveIt 2, and rmw_zenoh_cpp for transport (replacing DDS multicast discovery with a Zenoh router).

When to use¤

  • You want full motion planning (collision checking, trajectory smoothing) against a real or simulated robot.
  • You are starting a new project — ROS 2 Jazzy is the supported, current ROS LTS.
  • You need to drive the robot from any host OS (Docker Desktop on Mac / Windows is enough).

Trade-offs¤

What you get What you give up
Full MoveIt 2 motion planning + URSim simulator Docker required (heavier startup than in-process backends)
Zenoh transport avoids DDS multicast issues on Docker bridges Per-robot compose stacks need maintenance
Web-based RViz viewport + simulated teach pendant First-time setup is involved (see below)

Architecture¤

┌─────────────────┐    rosbridge       ┌─────────────────┐
│  compas_fab     │ ◄────WebSocket───► │  ros-bridge     │
│  (your script)  │     (port 9090)    │                 │
└─────────────────┘                    └────────┬────────┘
                                                │
                            ┌───────────────────┼───────────────────┐
                            │                   │                   │
                       ┌────▼─────┐      ┌──────▼─────┐      ┌──────▼──────┐
                       │ ur-driver│      │ moveit-demo│      │  ur-sim     │
                       │          │      │  (RViz)    │      │ (URSim)     │
                       └────┬─────┘      └──────┬─────┘      └──────┬──────┘
                            │                   │                   │
                            └─────────┬─────────┴───────────────────┘
                                      │
                              ┌───────▼────────┐
                              │ zenoh-router   │
                              └────────────────┘

All ROS 2 nodes are Zenoh clients pointing at a single zenoh-router service that federates traffic between containers. This eliminates the need for DDS multicast discovery, which is unreliable on Docker bridges and across host-OS boundaries.

Setup¤

Two compose files ship with the project, sharing the same Dockerfile and image (compas-fab/ros-jazzy-moveit2):

Lightweight test stack¤

For integration tests and headless service calls: just MoveIt + rosbridge + file server, no robot driver, no simulator, no GUI.

docker compose -f tests/integration_setup/docker-compose-ros2.yml up
Service Purpose Port
zenoh-router Zenoh router federating ROS 2 traffic —
moveit2-demo MoveIt 2 planning node —
ros2-bridge rosbridge WebSocket 9091
file-server HTTP server for URDF/mesh assets 9190

Full demo stack (URSim + GUI)¤

For end-to-end demos. It adds URSim, the real UR ROS 2 driver, and a noVNC RViz viewport on top of the test stack.

docker compose -f docs/installation/docker_files/ros2-ur10e-demo/docker-compose.yml up

This adds:

Service Purpose Port
ur-sim URSim simulator (UR5) 5900 (VNC), 6080 (noVNC pendant)
ur-driver UR ROS 2 driver —
gui noVNC web X11 server for RViz 8080

Open the simulated teach pendant at http://localhost:6080/vnc.html and power on the robot (Initialise → Brake release → Play) before issuing motion commands.

Open the RViz viewport at http://localhost:8080/vnc.html to see the planning scene rendered from the moveit2-demo container.

First example¤

Connect from Python and verify the bridge:

from compas_fab.backends import RosClient

with RosClient() as client:
    print("Connected: ", client.is_connected)

Loading robot descriptions over HTTP¤

For ROS 2 we recommend HttpFileServerLoader to load URDFs and meshes from the file-server container, instead of the legacy RosFileServerLoader (which depends on a ROS 1 service):

from compas_fab.backends import HttpFileServerLoader

loader = HttpFileServerLoader(base_url="http://localhost:9190")
urdf = loader.load_urdf("/robot_description", "std_msgs/String")

More examples¤

The example scripts in docs/backends/ros/files/ target both ROS 1 and ROS 2 back-ends because the RosClient API is unchanged — see the ROS + MoveIt 1 examples for the full list (kinematics, motion planning, Cartesian motion, pub/sub).

Notes on Zenoh¤

  • All ROS 2 services in this stack run as Zenoh clients (not the default DDS).
  • The session config lives at zenoh_session.json5.
  • POSIX shared-memory transport is disabled in that config because it fails under Rosetta 2 on Apple Silicon and is unnecessary for TCP-only inter-container traffic.
  • ZENOH_SESSION_CONFIG_URI takes a plain filesystem path despite the name, not a file:// URI.

Notes on controller rate¤

The UR driver defaults to a 500 Hz control loop. Inside Docker this can cause overrun warnings. The demo lowers this to 100 Hz via update_rate.yaml mounted at /etc/compas_fab/update_rate.yaml and passed to the launch file with update_rate_config_file:=....

Architecture: amd64 only¤

URSim and the noVNC X11 server are amd64-only. On Apple Silicon they run through Rosetta 2; platform: linux/amd64 is set on those services.

API reference¤