《ROS 2多协议传输控制器》使用 micro-ROS 协议+USB直连方式接入 ROS 系统

[小鱼]

《ROS 2多协议传输控制器》使用 micro-ROS 协议+USB直连方式接入 ROS 系统

开始前准备：

硬件：

1. 传输控制板*1
2. Type-B电源线*1
3. 9~28V电源

软件：

1. 安装Ubuntu的系统*1
2. 安装好ROS2 Humble以上版本ROS系统

1. micro-ROS Agent 和 消息接口下载与构建

在主目录下创建，ros2_transmission_ws 目录及子目录src（其他目录也可以）

mkdir  -p ~/ros2_transmission_ws/src

下载源码

cd ~/ros2_transmission_ws/src
git clone http://github.fishros.org/https://github.com/fishros/micro-ROS-Agent -b humble
git clone http://github.fishros.org/https://github.com/fishros/robot_interfaces
git clone http://github.fishros.org/https://github.com/micro-ROS/micro_ros_msgs.git -b humble

构建工作空间

cd ~/ros2_transmission_ws/
colcon build
---
Starting >>> micro_ros_agent
Starting >>> robot_interfaces                 
Finished <<< robot_interfaces [6.76s]                         
[Processing: micro_ros_agent]                             
--- stderr: micro_ros_agent                                
正克隆到 'xrceagent'...
切换到一个新分支 'ros2'
HEAD 目前位于 c25243c Enable Domain Override on Reference and XML Participant (#351)
CMake Warning (dev) at /usr/share/cmake-3.22/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
  The package name passed to `find_package_handle_standard_args` (tinyxml2)
  does not match the name of the calling package (TinyXML2).  This can lead
  to problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  cmake/modules/FindTinyXML2.cmake:40 (find_package_handle_standard_args)
  /opt/ros/humble/share/fastrtps/cmake/fastrtps-config.cmake:51 (find_package)
  CMakeLists.txt:153 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

---
Finished <<< micro_ros_agent [56.9s]

Summary: 2 packages finished [58.9s]
  1 package had stderr output: micro_ros_agent

看到：Summary: 2 packages finished [58.9s] 就表示构建成功了，中间的警告请忽略。

2.完成硬件连接

这种连接方式的特点是，通过网线将雷达和电脑(控制卡)直连，优点是稳定。

连接方式：

电脑<----Type-B|USB线----->控制板USB口
电源---->控制板电源口

3.使用配置助手修改配置

打开配置助手，扫描配置，确认如下选项的值，若不是，请手动修改。

配置项	描述	设置值
transport_mode	传输模式（例如以太网静态IP配置协议）	usb
usb_baudrate	USB传输速率	921600

传输模式我们这里采用 USB ，波特率设置为921600。

设置完成后请手动或者点击配置助手的重启设备进行重启。

5.运行agent,接收消息

进入到工作空间，运行agent, 其中 /dev/ttyUSB0 为设备端口号。

cd ~/ros2_transmission_ws/
source install/setup.bash
ros2 run micro_ros_agent micro_ros_agent serial --dev /dev/ttyUSB0 -b 921600 -v4
---
[1719816514.214416] info     | TermiosAgentLinux.cpp | init                     | running...             | fd: 3
[1719816514.214582] info     | Root.cpp           | set_verbose_level        | logger setup           | verbose_level: 4
[1719816514.297154] info     | Root.cpp           | create_client            | create                 | client_key: 0x0F1F6D30, session_id: 0x81
[1719816514.297189] info     | SessionManager.hpp | establish_session        | session established    | client_key: 0x0F1F6D30, address: 0
[1719816514.309030] info     | ProxyClient.cpp    | create_participant       | participant created    | client_key: 0x0F1F6D30, participant_id: 0x000(1)
[1719816514.313794] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x000(2), participant_id: 0x000(1)
[1719816514.317249] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x0F1F6D30, publisher_id: 0x000(3), participant_id: 0x000(1)
[1719816514.320991] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x0F1F6D30, datawriter_id: 0x000(5), publisher_id: 0x000(3)
[1719816514.325487] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x001(2), participant_id: 0x000(1)
[1719816514.329048] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x0F1F6D30, subscriber_id: 0x000(4), participant_id: 0x000(1)
[1719816514.332779] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x0F1F6D30, datareader_id: 0x000(6), subscriber_id: 0x000(4)
[1719816514.337931] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x002(2), participant_id: 0x000(1)
[1719816514.341453] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x0F1F6D30, publisher_id: 0x001(3), participant_id: 0x000(1)
[1719816514.345227] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x0F1F6D30, datawriter_id: 0x001(5), publisher_id: 0x001(3)
[1719816514.349723] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x003(2), participant_id: 0x000(1)
[1719816514.353673] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x0F1F6D30, subscriber_id: 0x001(4), participant_id: 0x000(1)
[1719816514.357576] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x0F1F6D30, datareader_id: 0x001(6), subscriber_id: 0x001(4)
[1719816514.362722] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x004(2), participant_id: 0x000(1)
[1719816514.366402] info     | ProxyClient.cpp    | create_publisher         | publisher created      | client_key: 0x0F1F6D30, publisher_id: 0x002(3), participant_id: 0x000(1)
[1719816514.370373] info     | ProxyClient.cpp    | create_datawriter        | datawriter created     | client_key: 0x0F1F6D30, datawriter_id: 0x002(5), publisher_id: 0x002(3)
[1719816514.375325] info     | ProxyClient.cpp    | create_topic             | topic created          | client_key: 0x0F1F6D30, topic_id: 0x005(2), participant_id: 0x000(1)
[1719816514.379148] info     | ProxyClient.cpp    | create_subscriber        | subscriber created     | client_key: 0x0F1F6D30, subscriber_id: 0x002(4), participant_id: 0x000(1)
[1719816514.382870] info     | ProxyClient.cpp    | create_datareader        | datareader created     | client_key: 0x0F1F6D30, datareader_id: 0x002(6), subscriber_id: 0x002(4)

看到上面的日志就表示连接成功了，接着就可以尝试订阅IO状态话题，打开新的终端，输入如下命令：

cd ~/ros2_transmission_ws/
source install/setup.bash
ros2 topic echo /read_io
---
analog: []
digital:
- 1
- 1
- 1
- 1
---
analog: []
digital:
- 1
- 1
- 1
- 1
---
...

可以看到这里每帧输出了四个数据，是四个输入IO的状态，这个话题默认以10Hz进行发布，发布频率可以修改。

使用 ros2 topic list 可以查看控制器节点可以支持的话题。

话题名称	消息接口	订阅/发布
/write_485	robot_interfaces/msg/RawUInt8	订阅
/write_can	robot_interfaces/msg/CanFrame	订阅
/write_io	robot_interfaces/msg/WriteIO	订阅
/read_485	robot_interfaces/msg/RawUInt8	发布
/read_can	robot_interfaces/msg/CanFrame	发布
/read_io	robot_interfaces/msg/ReadIO	发布

关于每个话题如何使用，可以参考例程篇介绍。

6. 设置固定USB端口

1. 编写udev规则：
   创建一个新的udev规则文件。通常，这些文件位于/etc/udev/rules.d/目录下。使用root用户或具有sudo权限的用户，在该目录下创建一个新的规则文件，例如99-usb-serial.rules：

   sudo nano /etc/udev/rules.d/99-usb-serial.rules
   

   然后在文件中添加以下规则：

   SUBSYSTEM=="tty", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", SYMLINK+="ttyUSBROS2Board"
   

   这个规则指定当SUBSYSTEM是tty，ATTRS{idVendor}是1a86，且ATTRS{idProduct}是7523时，udev应该创建一个名为ttyUSBROS2Board的符号链接。

2. 重新加载udev规则：
   在添加或修改了udev规则之后，需要重新加载udev规则，并触发事件来重新处理当前连接的设备：

   sudo udevadm control --reload-rules
   sudo udevadm trigger
   

   或者，您可以简单地重启系统来使更改生效。

3. 检查设备节点：
   现在，当您的USB设备连接到计算机时，您应该可以在/dev/目录下看到一个名为ttyUSBROS2Board的符号链接。您可以使用ls -l /dev/ttyUSBROS2Board来检查它是否指向了正确的设备节点（例如/dev/ttyUSB0、/dev/ttyUSB1等）。