机器人操作系统二（ROS2）- 启程 Departure_机器人 ros2 例程

是时候放下ROS1，开启ROS2的旅程了。It's time to put down ROS1 and start the journey of ROS2.

ROS2官方在线文档链接 ROS2 official online documentation：https://index.ros.org/doc/ros2/

ROS2教程文档使用说明与为什么选择ROS2？ROS2 tutorial documentation instructions and why choose ROS2?https://blog.csdn.net/ZhangRelay/article/details/93601114

ROS2常规学习路径 ROS2 regular learning path：

ROS2进阶学习路径 ROS2 advanced learning path：

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学习分享从安装配置开始，首先详细介绍教程，然后是两个专题：Navigation2和MoveIt!2。This article starts with ROS2 installation and configuration, first introduces the tutorial in detail, then two topics: Navigation2 and MoveIt!2.

安装详细过程 Installation detailed tutorial：ROS 2 Dashing Diademata安装和使用文档（含Linux、Windows和OS X）ROS 2 Dashing Diademata installation and documentation (including Linux, Windows and OS X)

ROS教程 ROS 2 tutorials：https://github.com/zhangrelay/ros2_tutorials

配置教程包 Tutorial package configuration：

1. 下载：git clone
2. 编译：colcon build
3. 使用：ros2 run

导入编译的环境 Import the compiled environment：

source install/setup.bash

输入ros2 run turtlesim，可以看到如下节点 Enter ros2 run turtlesim, you can see the following nodes：
draw_square        --prefix           turtle_teleop_key  
mimic              turtlesim_node

常用命令如下 Common commands are as follows：

1. ros2 run turtlesim turtlesim_node
2. ros2 topic list
3. ros2 run turtlesim draw_square
4. ros2 topic echo /turtle1/pose
5. ……

更多内容参考下图 For more details, please refer to the following figure：

欢迎大家下载案例调试玩耍， 更多内容后续介绍。You are welcome to download the case, debug and play, more will be introduced in subsequent articles.

思考题 Thinking：

回顾roslaunch， 写一个ros2 launch，同时启动turtlesim_node和draw_spuare。Looking back at roslaunch, write a ros2 launch and start both the turtlesim_node and draw_spuare node.

扩展题 Extended：

对比ROS1和ROS2的turtlesim包，分析和思考两代ROS编程和使用中的差异。Compare the turbulsim package of ROS1 and ROS2, analyze and think about the difference between the two generations of ROS in programming and use.

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 draw_square.launch.py

from launch import LaunchDescription
import launch_ros.actions
 
def generate_launch_description():
    return LaunchDescription([
        launch_ros.actions.Node(
            node_namespace= "ros2", package='turtlesim', node_executable='turtlesim_node', output='screen'),
        launch_ros.actions.Node(
            node_namespace= "ros2", package='turtlesim', node_executable='draw_square', output='screen'),
    ])
 
 

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教程 Tutorials

基础 Basic

• 使用colcon构建包 Using colcon to build packages
• 使用Ament Using Ament
• ament_cmake用户文档 ament_cmake User Documentation
• 交叉编译 Cross-Compilation 
• 关于ament和catkin（catment）的混合 On the mixing of ament and catkin (catment)
• 使用命令行工具进行自检 Introspection with command line tools
• RQt的概述和使用 Overview and Usage of RQt
• 将RQt插件移植到Windows Porting RQt plugins to Windows
• 通过命令行将ROS参数传递给节点 Passing ROS arguments to nodes via the command-line
• 使用Launch启动/监控多个节点 Launching/monitoring multiple nodes with Launch
• 使用多个ROS 2中间件实现 Working with multiple ROS 2 middleware implementations
• 在单个进程中组合多个节点 Composing multiple nodes in a single process
• msg和srv接口简介 Introduction to msg and srv interfaces
• ROS 2接口的新功能 New features in ROS 2 interfaces
• 定义自定义接口（msg / srv） Defining custom interfaces (msg/srv)
• 操作 Actions
• Eclipse氧气与ROS 2和rviz2 [社区贡献] Eclipse Oxygen with ROS 2 and rviz2 [community-contributed]
• 使用Eclipse Oxygen在Linux上构建ROS2 [社区贡献] Building ROS2 on Linux with Eclipse Oxygen [community-contributed]
• 为ROS 2构建实时Linux [社区贡献] Building Realtime Linux for ROS 2 [community-contributed]
• 发布带有bloom的ROS 2包 Releasing a ROS 2 package with bloom

高级 Advanced

• 实现自定义内存分配器 Implement a custom memory allocator

使用docker  Using Docker

• 在单个docker容器中运行2个节点[community-contributions] Running 2 nodes in a single docker container [community-contributed]
• 在2个独立的docker容器中运行2个节点[community-contributions] Running 2 nodes in 2 separate docker containers [community-contributed]

案例 Demos

• 使用服务质量设置来处理有损网络。Use quality-of-service settings to handle lossy networks.

• 管理具有托管生命周期的节点。Management of nodes with managed lifecycles.

• 高效的进程内通信。Efficient intra-process communication.

• ROS 1和ROS 2之间的桥接通信。Bridge communication between ROS 1 and ROS 2.

• 使用ROS 1桥接器使用rosbag记录和回放主题数据。Recording and playback of topic data with rosbag using the ROS 1 bridge.

• 使用ROS 2的Turtlebot 2演示。Turtlebot 2 demo using ROS 2.

• 使用ROS 2的TurtleBot 3演示。[社区贡献] TurtleBot 3 demo using ROS 2. [community-contributed]

• 使用tf2和ROS 2。Using tf2 with ROS 2.

• 编写使用ROS 2 API的实时安全代码。Write real-time safe code that uses the ROS 2 APIs.

• 使用rclpy API在Python中编写ROS 2程序。Use the rclpy API to write ROS 2 programs in Python.

• 使用机器人状态发布者发布联合状态和TF。Use the robot state publisher to publish joint states and TF.

• 使用DDS-Security。Use DDS-Security.

• 记录和记录器配置。Logging and logger configuration.

示例 Examples

• Python和C ++最小的例子。Python and C++ minimal examples.

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