README

ROS + Gazebo Sim demos

This package contains demos showing how to use Gazebo Sim with ROS.

Run Gazebo Sim

There’s a convenient launch file, try for example:

ros2 launch ros_gz_sim gz_sim.launch.py gz_args:="shapes.sdf"

Air pressure

Publishes fluid pressure readings.

ros2 launch ros_gz_sim_demos air_pressure.launch.py

This demo also shows the use of custom QoS parameters. The sensor data is published as as “best-effort”, so trying to subscribe to “reliable” data won’t work. See the difference between:

ros2 topic echo /air_pressure --qos-reliability best_effort

And

ros2 topic echo /air_pressure --qos-reliability reliable

Camera

Publishes RGB camera image and info.

Images can be exposed to ROS through ros_gz_bridge or ros_gz_image.

Using the image bridge (unidirectional, uses image_transport):

ros2 launch ros_gz_sim_demos image_bridge.launch.py

Using the regular bridge:

ros2 launch ros_gz_sim_demos camera.launch.py

To use a camera that only publishes information when triggered:

ros2 launch ros_gz_sim_demos triggered_camera.launch.py

Trigger the camera:

ros2 topic pub /camera/trigger std_msgs/msg/Bool "{data: true}" --once

Diff drive

Send commands to a differential drive vehicle and listen to its odometry.

ros2 launch ros_gz_sim_demos diff_drive.launch.py

Then unpause and send a command

ros2 topic pub /model/vehicle_blue/cmd_vel geometry_msgs/msg/Twist "{linear: {x: 5.0}, angular: {z: 0.5}}"

This demo also shows the use of custom QoS parameters. The commands are subscribed to as “reliable”, so trying to publish “best-effort” commands won’t work. See the difference between:

ros2 topic pub /model/vehicle_blue/cmd_vel geometry_msgs/msg/Twist "{linear: {x: 5.0}, angular: {z: 0.0}}" --qos-reliability reliable

And

ros2 topic pub /model/vehicle_blue/cmd_vel geometry_msgs/msg/Twist "{linear: {x: 5.0}, angular: {z: 0.0}}" --qos-reliability best_effort

Depth camera

Depth camera data can be obtained as:

• sensor_msgs/msg/Image, through ros_gz_bridge or ros_gz_image

• sensor_msgs/msg/PointCloud2, through ros_gz_point_cloud

Using the image bridge (unidirectional, uses image_transport):

ros2 launch ros_gz_sim_demos image_bridge.launch.py image_topic:=/depth_camera

TODO: Blocked by ros_gz_point_cloud issue.

Using Gazebo Sim plugin:

ros2 launch ros_gz_sim_demos depth_camera.launch.py

GPU lidar

GPU lidar data can be obtained as:

• sensor_msgs/msg/LaserScan, through the ros_gz_bridge

• sensor_msgs/msg/PointCloud2, through the ros_gz_bridge or ros_gz_point_cloud

Using the bridge:

ros2 launch ros_gz_sim_demos gpu_lidar_bridge.launch.py

TODO: Blocked by ros_gz_point_cloud issue.

Using Gazebo Sim plugin:

ros2 launch ros_gz_sim_demos gpu_lidar.launch.py

IMU

Publishes IMU readings.

ros2 launch ros_gz_sim_demos imu.launch.py

TODO: IMU display missing for RViz2

Magnetometer

Publishes magnetic field readings.

ros2 launch ros_gz_sim_demos magnetometer.launch.py

GNSS

Publishes satellite navigation readings, only available in Fortress on.

ros2 launch ros_gz_sim_demos navsat.launch.py

RGBD camera

RGBD camera data can be obtained as:

• sensor_msgs/msg/Image, through ros_gz_bridge or ros_gz_image

• sensor_msgs/msg/PointCloud2, through ros_gz_bridge or ros_gz_point_cloud

Using the image bridge (unidirectional, uses image_transport):

# RGB image
ros2 launch ros_gz_sim_demos image_bridge.launch.py image_topic:=/rgbd_camera/image
# Depth image
ros2 launch ros_gz_sim_demos image_bridge.launch.py image_topic:=/rgbd_camera/depth_image

Using the regular bridge:

ros2 launch ros_gz_sim_demos rgbd_camera_bridge.launch.py

TODO: Blocked by ros_gz_point_cloud issue.

Using Gazebo Sim plugin:

ros2 launch ros_gz_sim_demos rgbd_camera.launch.py

Battery

Get the current state of a battery.

ros2 launch ros_gz_sim_demos battery.launch.py

Then send a command so the vehicle moves and drains the battery

ros2 topic pub /model/vehicle_blue/cmd_vel geometry_msgs/msg/Twist "{linear: {x: 5.0}, angular: {z: 0.5}}"

Robot description publisher

Leverage the robot description publisher to spawn a new urdf model in gazebo and show it in rviz2. To try the demo launch:

ros2 launch ros_gz_sim_demos robot_description_publisher.launch.py

Joint States Publisher

Publishes joint states of the robot.

To try the demo launch:

ros2 launch ros_gz_sim_demos joint_states.launch.py

Bridging joint state and pose publishers

The launch file demonstrates bridging Gazebo poses to TFMessage to visualize the pose and transforms of a robot in rviz.

To try the demo launch:

ros2 launch ros_gz_sim_demos tf_bridge.launch.py