Unable to get publish topics in ROS2 - mobile robots

Question

I'm using py launch files for spawing a robot in Gazebo environment. System: ROS2-humble After the robot description files(xacro) are launched the ODOM, lidar and GPS (all are gazebo plugins) topics are not getting published. Initial launch file - here follows

import os

from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.actions import IncludeLaunchDescription
from launch.conditions import IfCondition
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node


def generate_launch_description():

    pkg_eve_car_gazebo = get_package_share_directory('eve_car_gazebo')
    pkg_eve_car_description = get_package_share_directory('eve_car_description')

    # Sart World
    start_world = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(pkg_eve_car_gazebo, 'launch', 'start_world_launch.py'),
        )
    )

    spawn_robot_world = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(pkg_eve_car_description, 'launch', 'spawn_robot_launch_v4.launch.py'),
        )
    )     

    return LaunchDescription([
        start_world,
        spawn_robot_world
    ])

[ERROR] [gzserver-1]: process has died [pid 19207, exit code 255, cmd 'gzserver /home/david/eve/install/eve_car_gazebo/share/eve_car_gazebo/worlds/eve_bot_empty.world -slibgazebo_ros_init.so -slibgazebo_ros_factory.so -slibgazebo_ros_force_system.so']

this error occurs when I launch. but the robot physics loads perfectly

I tried to rebuild and reinstall everything. But still no luck!

Answer 1

I presume you also launch the gzserver. By adding the verbose launch argument you get a possible inside in what is crashing the gzserver.

# Start Gazebo server
    start_gazebo_server_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')),
        condition=IfCondition(use_simulator),
        launch_arguments={'world': world,
                          'verbose' :"true"}.items())