Revision history [back]

Okay, after 3 hours or so I figured it out!

So, the problem seems to be with the shared src variable in the data_processor_all_launch.py. I slightly changed both files to enable launching the data_processor_launch.py with user-defined namespaces and to accept the namespace argument from top-level data_processor_all_launch.py.

This is now the data_processor_all_launch.py :

import os

from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch_ros.actions import Node
from launch.actions import DeclareLaunchArgument
from launch.actions import IncludeLaunchDescription
from launch.actions import GroupAction
from launch.substitutions import TextSubstitution
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch_ros.actions import PushRosNamespace
from launch.substitutions import LaunchConfiguration

def generate_launch_description():

ld = LaunchDescription()

package_prefix = get_package_share_directory('loading_motor_dt')
load_data_processor = PythonLaunchDescriptionSource([package_prefix,'/launch/data_processor_launch.py'])
traction_data_processor = PythonLaunchDescriptionSource([package_prefix,'/launch/data_processor_launch.py'])

launch_traction = GroupAction(
    actions=[
        # push-ros-namespace to set namespace of included nodes
        #PushRosNamespace('tb_lm_left'),
        IncludeLaunchDescription(load_data_processor, launch_arguments = {'namespace':'tb_tm'}.items()),
    ]
)
launch_loading = GroupAction(
    actions=[
        # push-ros-namespace to set namespace of included nodes
        #PushRosNamespace('tb_tm'),
        IncludeLaunchDescription(traction_data_processor, launch_arguments = {'namespace':'tb_tm'}.items()),
    ]
)

ld.add_action(launch_traction)
ld.add_action(launch_loading)
return ld

This is now the data_processor_launch.py:

import os
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch_ros.actions import Node
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import PushRosNamespace
from launch.actions import GroupAction

def generate_launch_description():

    ns = LaunchConfiguration('namespace', default = 'tb_lm_right')

    ld = LaunchDescription()
    config = os.path.join(
        get_package_share_directory('loading_motor_dt'),
        'config',
        'params.yaml'
    )

    data_processor=Node(
        package = 'loading_motor_dt',
        name = 'data_processor',
        executable = 'currentVoltageFlow',
        parameters = [config]
    )

    data_processor_with_ns = GroupAction(
        actions=[
            PushRosNamespace(ns),
            data_processor,
        ]
    )

    ld.add_action(data_processor_with_ns)
    return ld

And finally the result:

sejego@pop-os:~/dev_ws$ ros2 node list
/tb_lm_left/data_processor
/tb_tm/data_processor

Okay, after 3 hours or so I figured it out!

So, the problem seems to be with the shared src variable in the data_processor_all_launch.py. I slightly changed both files to enable launching the data_processor_launch.py with user-defined namespaces and to accept the namespace argument from top-level data_processor_all_launch.py.

This is now the data_processor_all_launch.py :

import os

from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch_ros.actions import Node
from launch.actions import DeclareLaunchArgument
from launch.actions import IncludeLaunchDescription
from launch.actions import GroupAction
from launch.substitutions import TextSubstitution
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch_ros.actions import PushRosNamespace
from launch.substitutions import LaunchConfiguration

def generate_launch_description():

ld = LaunchDescription()

package_prefix = get_package_share_directory('loading_motor_dt')
load_data_processor = PythonLaunchDescriptionSource([package_prefix,'/launch/data_processor_launch.py'])
traction_data_processor = PythonLaunchDescriptionSource([package_prefix,'/launch/data_processor_launch.py'])

launch_traction = GroupAction(
    actions=[
        # push-ros-namespace to set namespace of included nodes
        #PushRosNamespace('tb_lm_left'),
        IncludeLaunchDescription(load_data_processor, launch_arguments = {'namespace':'tb_tm'}.items()),
    ]
)
launch_loading = GroupAction(
    actions=[
        # push-ros-namespace to set namespace of included nodes
        #PushRosNamespace('tb_tm'),
        IncludeLaunchDescription(traction_data_processor, launch_arguments = {'namespace':'tb_tm'}.items()),
    ]
)

ld.add_action(launch_traction)
ld.add_action(launch_loading)
return ld

This is now the data_processor_launch.py:

import os
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch_ros.actions import Node
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import PushRosNamespace
from launch.actions import GroupAction

def generate_launch_description():

    ns = LaunchConfiguration('namespace', default = 'tb_lm_right')
'tb_tm')

    ld = LaunchDescription()
    config = os.path.join(
        get_package_share_directory('loading_motor_dt'),
        'config',
        'params.yaml'
    )

    data_processor=Node(
        package = 'loading_motor_dt',
        name = 'data_processor',
        executable = 'currentVoltageFlow',
        parameters = [config]
    )

    data_processor_with_ns = GroupAction(
        actions=[
            PushRosNamespace(ns),
            data_processor,
        ]
    )

    ld.add_action(data_processor_with_ns)
    return ld

And finally the result:

sejego@pop-os:~/dev_ws$ ros2 node list
/tb_lm_left/data_processor
/tb_tm/data_processor