ROS2入门17讲

问题1

输入命令：ros2 launch learning_urdf display.launch.py
[INFO] [launch]: All log files can be found below /home/xbc/.ros/log/2024-02-28-16-35-32-806540-xbc-virtual-machine-6445
[INFO] [launch]: Default logging verbosity is set to INFO
Task exception was never retrieved
future: <Task finished name='Task-2' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:226> exception=SubstitutionFailure("file not found: [Errno 2] No such file or directory: 'xacro'")>
Traceback (most recent call last):
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/substitutions/command.py", line 108, in perform
    result = subprocess.run(
  File "/usr/lib/python3.8/subprocess.py", line 493, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/usr/lib/python3.8/subprocess.py", line 858, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.8/subprocess.py", line 1704, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'xacro'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 228, in _process_one_event
    await self.__process_event(next_event)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 248, in __process_event
    visit_all_entities_and_collect_futures(entity, self.__context))
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
    futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
  [Previous line repeated 1 more time]
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
    sub_entities = entity.visit(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
    return self.execute(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/actions/node.py", line 444, in execute
    self._perform_substitutions(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/actions/node.py", line 399, in _perform_substitutions
    evaluated_parameters = evaluate_parameters(context, self.__parameters)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/utilities/evaluate_parameters.py", line 164, in evaluate_parameters
    output_params.append(evaluate_parameter_dict(context, param))
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/utilities/evaluate_parameters.py", line 132, in evaluate_parameter_dict
    evaluated_value = value.evaluate(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/parameter_descriptions.py", line 83, in evaluate
    self.__evaluated_parameter_value = perform_typed_substitution(
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/type_utils.py", line 548, in perform_typed_substitution
    perform_substitutions(context, cast(List[Substitution], value)),
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/perform_substitutions_impl.py", line 26, in perform_substitutions
    return ''.join([context.perform_substitution(sub) for sub in subs])
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/perform_substitutions_impl.py", line 26, in <listcomp>
    return ''.join([context.perform_substitution(sub) for sub in subs])
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_context.py", line 232, in perform_substitution
    return substitution.perform(self)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/substitutions/command.py", line 114, in perform
    raise SubstitutionFailure(f'file not found: {ex}')
launch.substitutions.substitution_failure.SubstitutionFailure: file not found: [Errno 2] No such file or directory: 'xacro'
Task exception was never retrieved
future: <Task finished name='Task-8' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:226> exception=RuntimeError('Signal event received before subprocess transport available.')>
Traceback (most recent call last):
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 228, in _process_one_event
    await self.__process_event(next_event)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 248, in __process_event
    visit_all_entities_and_collect_futures(entity, self.__context))
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
    sub_entities = entity.visit(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
    return self.execute(context)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/opaque_function.py", line 75, in execute
    return self.__function(context, *self.__args, **self.__kwargs)
  File "/opt/ros/foxy/lib/python3.8/site-packages/launch/actions/execute_process.py", line 443, in __on_signal_process_event
    raise RuntimeError('Signal event received before subprocess transport available.')
RuntimeError: Signal event received before subprocess transport available.
[INFO] [joint_state_publisher-1]: process started with pid [6448]
[joint_state_publisher-1] [INFO] [1709109333.375712714] [joint_state_publisher]: Waiting for robot_description to be published on the robot_description topic...
[ERROR] [joint_state_publisher-1]: process[joint_state_publisher-1] failed to terminate '5' seconds after receiving 'SIGINT', escalating to 'SIGTERM'
[INFO] [joint_state_publisher-1]: sending signal 'SIGTERM' to process[joint_state_publisher-1]
[ERROR] [joint_state_publisher-1]: process has died [pid 6448, exit code -15, cmd '/opt/ros/foxy/lib/joint_state_publisher/joint_state_publisher --ros-args'].

问题2

已经安装了 liburdfdom-tools

输入命令：urdf_to_graphviz mbot_base.urdf

Command 'urdf_to_graphviz' not found, did you mean:

  command 'urdf_to_graphiz' from deb liburdfdom-tools (1.0.4+ds-2)

Try: sudo apt install <deb name>