ros_gz_sim_demos

ros_gz_sim

Demos using Gazebo Sim simulation with ROS.
使用 Gazebo Sim 模擬和 ROS 的示範。

README  自述文件 

ROS + Gazebo Sim demos
ROS + Gazebo Sim 示範 

This package contains demos showing how to use Gazebo Sim with ROS.
該軟體包包含演示如何將 Gazebo Sim 與 ROS 結合使用的演示。

Run Gazebo Sim
運行 Gazebo Sim 

There’s a convenient launch file, try for example:
有一個方便的啟動文件，例如嘗試：

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

Air pressure
氣壓 

Publishes fluid pressure readings.
發布流體壓力讀數。

ros2 launch ros_gz_sim_demos air_pressure.launch.xml

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:
此演示還展示了自訂 QoS 參數的使用。感測器數據以“盡力而為”的方式發布，因此嘗試訂閱“可靠”數據將無法正常工作。以下是兩者之間的差異：

ros2 topic echo /air_pressure --qos-reliability best_effort

And  和

ros2 topic echo /air_pressure --qos-reliability reliable

Battery  電池 

Get the current state of a battery.
取得電池的目前狀態。

ros2 launch ros_gz_sim_demos battery.launch.py

Then send a command so the vehicle moves and drains the battery.
然後發送命令讓車輛移動並耗盡電池。

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

Camera  房間 

Publishes RGB camera image and info.
發布 RGB 相機影像和資訊。

Images can be exposed to ROS through ros_gz_bridge or ros_gz_image.
影像可以透過 ros_gz_bridge 或 ros_gz_image 暴露給 ROS。

Using the image bridge (unidirectional, uses image_transport):
使用影像橋（單向，使用 image_transport ）：

ros2 launch ros_gz_sim_demos image_bridge.launch.py

Using the regular bridge:
使用常規橋接：

ros2 launch ros_gz_sim_demos camera.launch.xml

To use a camera that only publishes information when triggered:
若要使用僅在觸發時發布資訊的相機：

ros2 launch ros_gz_sim_demos triggered_camera.launch.xml

Trigger the camera:  觸發相機：

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

Diff drive  差速驅動 

Send commands to a differential drive vehicle and listen to its odometry.
向差速驅動車輛發送命令並監聽其里程表。

ros2 launch ros_gz_sim_demos diff_drive.launch.xml

Then send a command
然後發送命令

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:
此演示還展示了自訂 QoS 參數的使用。這些命令被訂閱為“可靠”，因此嘗試發布“盡力而為”的命令將不起作用。以下是兩者之間的差異：

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

And  和

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
深度相機 

Depth camera data can be obtained as:
深度相機數據可以透過以下方式取得：

  • sensor_msgs/msg/Image, through ros_gz_bridge or ros_gz_image
    sensor_msgs/msg/Image ，透過 ros_gz_bridge 或 ros_gz_image

  • sensor_msgs/msg/PointCloud2, through ros_gz_point_cloud
    sensor_msgs/msg/PointCloud2 ，透過 ros_gz_point_cloud

Using the image bridge (unidirectional, uses image_transport):
使用影像橋（單向，使用 image_transport ）：

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

TODO: Blocked by ros_gz_point_cloud issue.
TODO ：被 ros_gz_point_cloud 問題阻止。

Using Gazebo Sim plugin:
使用 Gazebo Sim 外掛：

ros2 launch ros_gz_sim_demos depth_camera.launch.py

GPU lidar  GPU 光達 

GPU lidar data can be obtained as:
GPU 光達資料取得方式如下：

  • sensor_msgs/msg/LaserScan, through the ros_gz_bridge
    sensor_msgs/msg/LaserScan ，透過 ros_gz_bridge

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

Using the bridge:  使用橋接器：

ros2 launch ros_gz_sim_demos gpu_lidar_bridge.launch.xml

TODO: Blocked by ros_gz_point_cloud issue.
TODO ：被 ros_gz_point_cloud 問題阻止。

Using Gazebo Sim plugin:
使用 Gazebo Sim 外掛：

ros2 launch ros_gz_sim_demos gpu_lidar.launch.py

IMU  慣性測量單元 

Publishes IMU readings.  發布 IMU 讀數。

ros2 launch ros_gz_sim_demos imu.launch.xml

TODO: IMU display missing for RViz2
TODO ：RViz2 缺少 IMU 顯示

Magnetometer
磁力儀 

Publishes magnetic field readings.
發布磁場讀數。

ros2 launch ros_gz_sim_demos magnetometer.launch.xml

GNSS  全球導航衛星系統 

Publishes satellite navigation readings, only available in Fortress on.
發布衛星導航讀數，僅在 Fortress 上提供。

GNSS information can be obtained as:
GNSS 資訊可以透過以下方式取得：

# sensor_msgs/msg/NavSatFix
ros2 launch ros_gz_sim_demos navsat.launch.xml
# gps_msgs/msg/GPSFix
ros2 launch ros_gz_sim_demos navsat_gpsfix.launch.xml

RGBD camera  RGBD 相機 

RGBD camera data can be obtained as:
RGBD 相機數據可以透過以下方式取得：

  • sensor_msgs/msg/Image, through ros_gz_bridge or ros_gz_image
    sensor_msgs/msg/Image ，透過 ros_gz_bridge 或 ros_gz_image

  • sensor_msgs/msg/PointCloud2, through ros_gz_bridge or ros_gz_point_cloud
    sensor_msgs/msg/PointCloud2 ，透過 ros_gz_bridge 或 ros_gz_point_cloud

Using the image bridge (unidirectional, uses image_transport):
使用影像橋（單向，使用 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:
使用常規橋接：

ros2 launch ros_gz_sim_demos rgbd_camera_bridge.launch.xml

TODO: Blocked by ros_gz_point_cloud issue.
TODO ：被 ros_gz_point_cloud 問題阻止。

Using Gazebo Sim plugin:
使用 Gazebo Sim 外掛：

ros2 launch ros_gz_sim_demos rgbd_camera.launch.py

Robot description publisher
機器人描述發布者 

Leverage the robot description publisher to spawn a new urdf model in gazebo and show it in rviz2. To try the demo launch:
利用機器人描述發佈器在 Gazebo 中產生一個新的 URDF 模型，並在 rviz2 中展示。若要試用演示版本，請啟動：

ros2 launch ros_gz_sim_demos robot_description_publisher.launch.py

Joint States Publisher
美國出版商 

Publishes joint states of the robot.
發布機器人的關節狀態。

To try the demo launch:
若要嘗試示範啟動：

ros2 launch ros_gz_sim_demos joint_states.launch.py

Bridging joint state and pose publishers
連結聯合狀態與姿勢發布者 

The launch file demonstrates bridging Gazebo poses to TFMessage to visualize the pose and transforms of a robot in rviz.
啟動檔案示範如何將 Gazebo 姿勢與 TFMessage 連接起來，以便在 rviz 中可視化機器人的姿勢和變換。

To try the demo launch:
若要嘗試示範啟動：

ros2 launch ros_gz_sim_demos tf_bridge.launch.xml

Managing Entities
管理實體 

The ros_gz_sim package provides a set of utilities for managing entities (models, lights, links, etc.) in Gazebo simulations through ROS 2. This package enables seamless communication between ROS 2 and Gazebo, allowing you to:
ros_gz_sim 套件提供了一組實用程序，用於透過 ROS 2 管理 Gazebo 模擬中的實體（模型、燈光、連結等）。該包支援 ROS 2 和 Gazebo 之間的無縫通信，使您能夠：

  • Spawn entities: Add new models and objects to a running Gazebo simulation
    生成實體 ：在正在運行的 Gazebo 模擬中新增模型和對象

  • Set entity poses: Dynamically adjust the position and orientation of existing entities
    設定實體姿勢 ：動態調整現有實體的位置與方向

  • Delete entities: Remove entities from the simulation environment
    刪除實體 ：從模擬環境中刪除實體

Launching Gazebo
啟動 Gazebo 

gz sim -v 4 ~/ros2_ws/src/ros_gz/ros_gz_sim_demos/worlds/default.sdf

1. Spawning Entities
1. 生成實體 

Spawn new entities into the simulation:
在模擬中產生新的實體：

  1. Run the ROS-Gazebo bridge for the spawn service:
    為 spawn 服務運行 ROS-Gazebo 橋：

ros2 run ros_gz_bridge parameter_bridge /world/default/create@ros_gz_interfaces/srv/SpawnEntity

  1. Spawn your entity:  產生你的實體：

ros2 run ros_gz_sim spawn_entity --name <model_name> --sdf_filename <path_to_sdf_file> [--pos x y z] [--quat x y z w | --euler roll pitch yaw]

Example:  例子：

ros2 run ros_gz_sim spawn_entity --name cardboard_box --sdf_filename $(ros2 pkg prefix ros_gz_sim_demos)/share/ros_gz_sim_demos/models/cardboard_box/model.sdf --pos 1.0 2.0 0.5 --euler 0.0 0.0 1.57

or  或者

ros2 run ros_gz_sim spawn_entity --name cardboard_box --sdf_filename /full/path/to/ros_gz_ws/src/ros_gz_sim_demos/models/cardboard_box/model.sdf --pos 1.0 2.0 0.5 --euler 0.0 0.0 1.57

spawn_entity

2. Setting Entity Poses
2. 設定實體姿勢 

Dynamically adjust the position and orientation of existing entities:
動態調整現有實體的位置和方向：

  1. Run the ROS-Gazebo bridge for the set pose service:
    運行 ROS-Gazebo 橋接器來設定姿勢服務：

ros2 run ros_gz_bridge parameter_bridge /world/default/set_pose@ros_gz_interfaces/srv/SetEntityPose

  1. Set the entity’s pose:  設定實體的姿勢：

ros2 run ros_gz_sim set_entity_pose [--name NAME | --id ID] [--type TYPE] [--pos X Y Z] [--quat X Y Z W | --euler ROLL PITCH YAW]

Examples:  例子：

Using entity name with Euler angles for rotation:
使用帶有歐拉角的實體名稱進行旋轉：

ros2 run ros_gz_sim set_entity_pose --name cardboard_box --pos 3.0 4.0 1.0 --euler 0.0 0.0 1.57

Using entity ID with quaternion for rotation:
使用四元數的實體 ID 進行旋轉：

ros2 run ros_gz_sim set_entity_pose --id 8 --pos 3.0 4.0 1.0 --quat 0.0 0.0 0.7071 0.7071

set_entity

3. Deleting Entities
3. 刪除實體 

Remove entities from the simulation:
從模擬中刪除實體：

  1. Run the ROS-Gazebo bridge for the delete service:
    運行 ROS-Gazebo 橋接器以刪除服務：

ros2 run ros_gz_bridge parameter_bridge /world/default/remove@ros_gz_interfaces/srv/DeleteEntity

  1. Delete the entity:  刪除實體：

ros2 run ros_gz_sim delete_entity [--name NAME | --id ID] [--type TYPE]

Examples:  例子：

Using entity name:  使用實體名稱：

ros2 run ros_gz_sim delete_entity --name cardboard_box

Using entity ID:  使用實體 ID：

ros2 run ros_gz_sim delete_entity --id 8

Using a specific entity type:
使用特定的實體類型：

ros2 run ros_gz_sim delete_entity --name cardboard_box --type 2


Entity Type Reference
實體類型參考 

When using the set_entity_pose and delete_entity commands, you can specify the entity type using the --type flag. The following type values are available:
使用 set_entity_pose 和 delete_entity 指令時，可以使用 --type 標誌指定實體類型。可用的類型值如下：

Value  價值

Entity Type  實體類型

0

NONE

1

LIGHT

2

LINK

3

VISUAL

4

COLLISION

5

SENSOR

6

MODEL (default)  型號（預設）