gazebo显示不了fishbot机器人模型

[刘豪]

3月份购买了两套fishbot小车，按照先学习理论的思路我先开始学习了《动手学ros》，在学习到了机器人仿真章节（第九章→”9.2为机器人URDF模型注入物理属性并在Gazebo中显示“→ 4. 将启动gazebo和生产fishbot写成launch文件，小节），
在利用launch文件自动导入fishbot小车模型文件时出现问题：，

• 我在终端窗口执行完列表命令执行完命令，如下：
  (base) rosmaster@ubuntu:~/fishbot_ws/src/fishbot_description$ ros2 launch fishbot_description gazebo.launch.py
  之后，出现如下反馈提示：
  
  
  gazebo2是启动了，但是界面空空如也。

终端反馈的原始信息下如：

[INFO] [launch]: All log files can be found below /home/rosmaster/.ros/log/2024-05-18-19-25-58-941896-ubuntu-3989
[INFO] [launch]: Default logging verbosity is set to INFO
[INFO] [gazebo-1]: process started with pid [3991]
[INFO] [spawn_entity.py-2]: process started with pid [3993]
[spawn_entity.py-2] Traceback (most recent call last):
[spawn_entity.py-2] File "/opt/ros/foxy/lib/gazebo_ros/spawn_entity.py", line 33, in <module>
[spawn_entity.py-2] from rclpy.node import Node
[spawn_entity.py-2] File "/opt/ros/foxy/lib/python3.8/site-packages/rclpy/node.py", line 42, in <module>
[spawn_entity.py-2] from rclpy.client import Client
[spawn_entity.py-2] File "/opt/ros/foxy/lib/python3.8/site-packages/rclpy/client.py", line 22, in <module>
[spawn_entity.py-2] from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
[spawn_entity.py-2] File "/opt/ros/foxy/lib/python3.8/site-packages/rclpy/impl/implementation_singleton.py", line 31, in <module>
[spawn_entity.py-2] rclpy_implementation = _import('._rclpy')
[spawn_entity.py-2] File "/opt/ros/foxy/lib/python3.8/site-packages/rclpy/impl/init.py", line 28, in _import
[spawn_entity.py-2] return importlib.import_module(name, package='rclpy')
[spawn_entity.py-2] File "/home/rosmaster/miniconda3/lib/python3.9/importlib/init.py", line 127, in import_module
[spawn_entity.py-2] return _bootstrap._gcd_import(name[level:], package, level)
[spawn_entity.py-2] ModuleNotFoundError: No module named 'rclpy._rclpy'
[spawn_entity.py-2] The C extension '/opt/ros/foxy/lib/python3.8/site-packages/rclpy/_rclpy.cpython-39-x86_64-linux-gnu.so' isn't present on the system. Please refer to 'https://index.ros.org/doc/ros2/Troubleshooting/Installation-Troubleshooting/#import-failing-without-library-present-on-the-system' for possible solutions
[ERROR] [spawn_entity.py-2]: process has died [pid 3993, exit code 1, cmd '/opt/ros/foxy/lib/gazebo_ros/spawn_entity.py -entity fishbot -file /home/rosmaster/fishbot_ws/src/fishbot_description/install/fishbot_description/share/fishbot_description/urdf/fishbot_gazebo.urdf --ros-args'].
[gazebo-1] Gazebo multi-robot simulator, version 11.11.0
[gazebo-1] Copyright (C) 2012 Open Source Robotics Foundation.
[gazebo-1] Released under the Apache 2 License.
[gazebo-1] http://gazebosim.org
[gazebo-1]
[gazebo-1] Gazebo multi-robot simulator, version 11.11.0
[gazebo-1] Copyright (C) 2012 Open Source Robotics Foundation.
[gazebo-1] Released under the Apache 2 License.
[gazebo-1] http://gazebosim.org
[gazebo-1]
[gazebo-1] [INFO] [1716031561.325380813] [gazebo_ros_node]: ROS was initialized without arguments.

追加内容1：

• 列表我的功能包结构、lanuch文件内容如下，
  
  
  launch文件原码如下：

import os
from launch import LaunchDescription
from launch.actions import ExecuteProcess
from launch_ros.actions import Node
from launch_ros.substitutions import FindPackageShare


def generate_launch_description():
    robot_name_in_model = 'fishbot'
    package_name = 'fishbot_description'
    urdf_name = "fishbot_gazebo.urdf"

    ld = LaunchDescription()
    pkg_share = FindPackageShare(package=package_name).find(package_name) 
    urdf_model_path = os.path.join(pkg_share, f'urdf/{urdf_name}')

    # Start Gazebo server
    start_gazebo_cmd = ExecuteProcess(
        cmd=['gazebo', '--verbose', '-s', 'libgazebo_ros_factory.so'],
        output='screen')

    # Launch the robot
    spawn_entity_cmd = Node(
        package='gazebo_ros', 
        executable='spawn_entity.py',
        arguments=['-entity', robot_name_in_model,  '-file', urdf_model_path ], output='screen')

    ld.add_action(start_gazebo_cmd)
    ld.add_action(spawn_entity_cmd)


    return ld

追加信息2：

• 另外，我的模型文件是正常的（从小鱼的github网址中下载的），我使用rqt中的service calls 的xml方式导入到gazebo是显示正常的，见下图：
  

  此问题我已经重新做过很多遍这个例程，网上找了很多方法，一直不能解决，反复折腾已经5天了，还请知道的兄弟帮忙研究下可能是那里的问题。
  我看了一下，这个问题不解决，后面的章节无法进行，因为都是相互关联的内容，谢谢！

[niuniu36]

@刘豪 可以试试退出conda：conda deactivate 后再运行