ROS2机器人开发书籍中6.4.4不发布话题的问题

机器人小伊

从您提供的描述和代码来看，您在尝试使用ROS 2和Gazebo来模拟一个机器人，并期望在仿真中看到特定的话题（如/odom），但实际上并没有看到这个话题。这里有几个可能的原因和解决方案：

1. 检查Gazebo插件的加载

首先，确保gazebo_control_plugin.xacro中的插件确实被加载到了URDF模型中。从您提供的fishbot.urdf.xacro文件来看，您已经包含了gazebo_control_plugin.xacro，但没有显式调用<xacro:gazebo_control_plugin />宏。虽然您可能通过其他方式（如fishbot_ros2_control.xacro）隐式地包含了它，但最好还是确认一下。

解决方案：

确保在URDF文件中正确调用了<xacro:gazebo_control_plugin />宏。
检查fishbot_ros2_control.xacro文件，看是否有任何可能影响插件加载的代码。

2. ROS 2 控制配置

由于您提到了ros2_control，确保您的控制配置是正确的。ros2_control需要正确的硬件描述（通常通过YAML文件提供）和控制器配置（同样在YAML文件中）。

解决方案：

检查是否有对应的控制器配置文件（如YAML文件），并确保它们被正确加载。
确保控制器节点正在运行，并且没有报告任何错误。

3. 重新构建和清理

有时，旧的构建文件可能会干扰新的构建。尝试清理您的构建目录并重新构建。

解决方案：

在工作空间目录中运行colcon build --packages-select fishbot_description --symlink-install来仅构建fishbot_description包。
清理构建目录：rm -rf build install log，然后重新构建。

4. 检查Gazebo和ROS 2的日志

查看Gazebo和ROS 2的日志文件可能会提供更多关于为什么话题没有发布的线索。

解决方案：

查看~/.ros/log/目录下的ROS 2日志文件。
查看Gazebo的终端输出或日志文件，看是否有任何错误或警告。

5. 验证URDF和XACRO文件

使用check_urdf工具验证URDF文件是否没有错误。

解决方案：

运行ros2 run robot_state_publisher robot_state_publisher fishbot_description/urdf/fishbot/fishbot.urdf.xacro，并使用check_urdf命令来验证URDF。

6. 确保Gazebo和ROS 2的兼容性

确保您使用的Gazebo和ROS 2版本是兼容的。

解决方案：

查阅ROS 2和Gazebo的官方文档，确认您使用的版本是否相互兼容。

按照这些步骤检查和调整您的设置，您应该能够更接近问题的根源，并找到解决方案。如果问题仍然存在，您可能需要更详细地检查您的ROS 2控制配置或寻求来自ROS 2社区的帮助。

以上为生成回答，仅供参考～

小鱼

@1286588184 没看到有启动gazebo欸

小鱼

@1286588184 在 ROS2机器人开发书籍中6.4.4不发布话题的问题中说：

重新构建与启动仿真

你并没有启动仿真

1286588184

@小鱼

是启动这个launch文件吗

an@911:~/ros2bookcode/chapt6$ ros2 launch fishbot_description gazebo_sim.launch.py
[INFO] [launch]: All log files can be found below /home/an/.ros/log/2024-09-13-16-06-39-026307-911-4420
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [robot_state_publisher-1]: process started with pid [4422]
[INFO] [gzserver-2]: process started with pid [4424]
[INFO] [gzclient-3]: process started with pid [4426]
[INFO] [spawn_entity.py-4]: process started with pid [4428]
[robot_state_publisher-1] [INFO] [1726214799.434220248] [robot_state_publisher]: got segment back_caster_link
[robot_state_publisher-1] [INFO] [1726214799.434303381] [robot_state_publisher]: got segment base_footprint
[robot_state_publisher-1] [INFO] [1726214799.434308766] [robot_state_publisher]: got segment base_link
[robot_state_publisher-1] [INFO] [1726214799.434311465] [robot_state_publisher]: got segment camera_link
[robot_state_publisher-1] [INFO] [1726214799.434314019] [robot_state_publisher]: got segment camera_optical_link
[robot_state_publisher-1] [INFO] [1726214799.434316513] [robot_state_publisher]: got segment front_caster_link
[robot_state_publisher-1] [INFO] [1726214799.434318834] [robot_state_publisher]: got segment imu_link
[robot_state_publisher-1] [INFO] [1726214799.434321177] [robot_state_publisher]: got segment laser_cylinder_link
[robot_state_publisher-1] [INFO] [1726214799.434323514] [robot_state_publisher]: got segment laser_link
[robot_state_publisher-1] [INFO] [1726214799.434325751] [robot_state_publisher]: got segment left_wheel_link
[robot_state_publisher-1] [INFO] [1726214799.434328088] [robot_state_publisher]: got segment right_wheel_link
[gzclient-3] Gazebo multi-robot simulator, version 11.10.2
[gzclient-3] Copyright (C) 2012 Open Source Robotics Foundation.
[gzclient-3] Released under the Apache 2 License.
[gzclient-3] http://gazebosim.org
[gzclient-3] 
[gzserver-2] Gazebo multi-robot simulator, version 11.10.2
[gzserver-2] Copyright (C) 2012 Open Source Robotics Foundation.
[gzserver-2] Released under the Apache 2 License.
[gzserver-2] http://gazebosim.org
[gzserver-2] 
[spawn_entity.py-4] [INFO] [1726214799.722044380] [spawn_entity]: Spawn Entity started
[spawn_entity.py-4] [INFO] [1726214799.722312098] [spawn_entity]: Loading entity published on topic /robot_description
[spawn_entity.py-4] /opt/ros/humble/local/lib/python3.10/dist-packages/rclpy/qos.py:307: UserWarning: DurabilityPolicy.RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL is deprecated. Use DurabilityPolicy.TRANSIENT_LOCAL instead.
[spawn_entity.py-4]   warnings.warn(
[spawn_entity.py-4] [INFO] [1726214799.723847055] [spawn_entity]: Waiting for entity xml on /robot_description
[spawn_entity.py-4] [INFO] [1726214799.735158585] [spawn_entity]: Waiting for service /spawn_entity, timeout = 30
[spawn_entity.py-4] [INFO] [1726214799.735467999] [spawn_entity]: Waiting for service /spawn_entity
[spawn_entity.py-4] [INFO] [1726214800.492925943] [spawn_entity]: Calling service /spawn_entity
[gzclient-3] [Msg] Waiting for master.
[gzclient-3] [Msg] Connected to gazebo master @ http://127.0.0.1:11345
[gzclient-3] [Msg] Publicized address: 10.139.109.189
[gzclient-3] [Err] [InsertModelWidget.cc:403] Missing model.config for model "/home/an/.gazebo/models/.git"
[gzserver-2] [Msg] Waiting for master.
[gzserver-2] [Msg] Connected to gazebo master @ http://127.0.0.1:11345
[gzserver-2] [Msg] Publicized address: 10.139.109.189
[gzserver-2] [Msg] Loading world file [/home/an/ros2bookcode/chapt6/install/fishbot_description/share/fishbot_description/world/custom_room.world]
[gzserver-2] [Wrn] [Event.cc:61] Warning: Deleting a connection right after creation. Make sure to save the ConnectionPtr from a Connect call
[gzserver-2] [INFO] [1726214801.132406165] [depth_camera]: Publishing camera info to [/camera_sensor/camera_info]
[gzserver-2] [INFO] [1726214801.132921282] [depth_camera]: Publishing depth camera info to [/camera_sensor/depth/camera_info]
[gzserver-2] [INFO] [1726214801.133263243] [depth_camera]: Publishing pointcloud to [/camera_sensor/points]
[spawn_entity.py-4] [INFO] [1726214801.196537173] [spawn_entity]: Spawn status: SpawnEntity: Successfully spawned entity [fishbot]
[gzserver-2] [Err] [Plugin.hh:212] Failed to load plugin libgazebo_ros2_control.so: libgazebo_ros2_control.so: cannot open shared object file: No such file or directory
[INFO] [spawn_entity.py-4]: process has finished cleanly [pid 4428]
[INFO] [ros2-5]: process started with pid [4632]
[ros2-5] usage: ros2 [-h] [--use-python-default-buffering]
[ros2-5]             Call `ros2 <command> -h` for more detailed usage. ...
[ros2-5] ros2: error: argument Call `ros2 <command> -h` for more detailed usage.: invalid choice: 'control' (choose from 'action', 'bag', 'component', 'daemon', 'doctor', 'extension_points', 'extensions', 'interface', 'launch', 'lifecycle', 'multicast', 'node', 'param', 'pkg', 'run', 'security', 'service', 'topic', 'wtf')
[ERROR] [ros2-5]: process has died [pid 4632, exit code 2, cmd 'ros2 control load_controller --set-state active fishbot_joint_state_broadcaster'].
[INFO] [ros2-6]: process started with pid [4634]
[ros2-6] usage: ros2 [-h] [--use-python-default-buffering]
[ros2-6]             Call `ros2 <command> -h` for more detailed usage. ...
[ros2-6] ros2: error: argument Call `ros2 <command> -h` for more detailed usage.: invalid choice: 'control' (choose from 'action', 'bag', 'component', 'daemon', 'doctor', 'extension_points', 'extensions', 'interface', 'launch', 'lifecycle', 'multicast', 'node', 'param', 'pkg', 'run', 'security', 'service', 'topic', 'wtf')
[ERROR] [ros2-6]: process has died [pid 4634, exit code 2, cmd 'ros2 control load_controller --set-state active fishbot_diff_drive_controller'].
[gzserver-2] [Wrn] [Publisher.cc:135] Queue limit reached for topic /gazebo/default/pose/local/info, deleting message. This warning is printed only once.

da35a272-7252-4049-bf28-981b79f90aa2-图片.png

现在是这样的

an@911:~$ ros2 topic list
/camera_sensor/camera_info
/camera_sensor/depth/camera_info
/camera_sensor/depth/image_raw
/camera_sensor/image_raw
/camera_sensor/points
/clicked_point
/clock
/goal_pose
/imu
/initialpose
/joint_states
/parameter_events
/performance_metrics
/robot_description
/rosout
/scan
/tf
/tf_static

小鱼

@1286588184 你是跳着看的书吗，前面的装依赖之类的是不是没看和操作

1286588184

我又试了一下，把这里的注释取消掉就正常出现cmd和odem话题了

<!-- Gazebo 插件 -->
    <xacro:include filename="$(find fishbot_description)/urdf/fishbot/plugins/gazebo_control_plugin.xacro" />
    <!-- <xacro:gazebo_control_plugin /> -->

an@911:~$ ros2 topic list
/camera_sensor/camera_info
/camera_sensor/depth/camera_info
/camera_sensor/depth/image_raw
/camera_sensor/image_raw
/camera_sensor/points
/clock
/cmd_vel
/imu
/joint_states
/odom
/parameter_events
/performance_metrics
/robot_description
/rosout
/scan
/tf
/tf_static

不太明白这里为什么被注释了
这个代码我是直接下载的，一开始就是带注释的

小鱼

@1286588184 在 ROS2机器人开发书籍中6.4.4不发布话题的问题中说：

[Err] [Plugin.hh:212] Failed to load plugin libgazebo_ros2_control.so: libgazebo_ros2_control.so: cannot open shared object file: No such file or directory

这里的报错很明显了，没有安装依赖

小鱼

@1286588184 建议跟着书操作，了解下代码为什么这么写和注释

1286588184

@小鱼我发现了这个，但书里没找到关于这个依赖的安装信息，只在6.4.2中提到安装gazebo依赖

n@911:~$ sudo apt install ros-humble-gazebo-ros-pkgs
正在读取软件包列表... 完成
正在分析软件包的依赖关系树... 完成
正在读取状态信息... 完成                 
ros-humble-gazebo-ros-pkgs 已经是最新版 (3.7.0-1jammy.20240820.174040)。
下列软件包是自动安装的并且现在不需要了：
  libpython2-stdlib libpython2.7-minimal libpython2.7-stdlib
  python-pkg-resources python-setuptools python2 python2-minimal python2.7
  python2.7-minimal
使用'sudo apt autoremove'来卸载它(它们)。
升级了 0 个软件包，新安装了 0 个软件包，要卸载 0 个软件包，有 103 个软件包未被升级。

我安装了这个，上面报错显示的那个包我在文件夹里找到了，但就是不起作用，有什么办法吗，或者说书里具体哪里有讲这个

我是从第六章开始学的，之前一直跟着视频课的动手学ros2,正好学到机器人gazebo仿真出问题了，然后就从这本书的第六章开始学的

小鱼

@1286588184 不是这个，书中应该还提到了ros2_control依赖

小鱼

@1286588184 代码对应的是这章结束的代码，不是刚好6.4的，你运行的代码出现了第六章最后面才出现的内容

1286588184

@小鱼好的感谢小鱼老师我找到了这章的代码我打算重新去理解编写一步一步按书上来