Files
RDC_Simulation/gazebo/launch/drone_landing.launch.py
2026-01-02 06:09:15 +00:00

131 lines
4.3 KiB
Python

#!/usr/bin/env python3
"""
Gazebo Launch File - Drone Landing Simulation
Launches Gazebo with the world and spawns the drone.
Supports both 'gz' (newer) and 'ign' (Fortress) commands.
"""
import os
import shutil
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
from launch.conditions import IfCondition
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration, PathJoinSubstitution
from launch_ros.actions import Node
def get_gazebo_command():
"""Determine whether to use 'gz' or 'ign' command."""
if shutil.which('gz'):
return 'gz'
elif shutil.which('ign'):
return 'ign'
else:
# Default to gz, will fail with helpful error
return 'gz'
def generate_launch_description():
"""Generate the launch description."""
script_dir = os.path.dirname(os.path.abspath(__file__))
gazebo_dir = os.path.dirname(script_dir)
world_file = os.path.join(gazebo_dir, 'worlds', 'drone_landing.sdf')
model_path = os.path.join(gazebo_dir, 'models')
drone_model = os.path.join(model_path, 'drone', 'model.sdf')
gz_resource_path = os.environ.get('GZ_SIM_RESOURCE_PATH', '')
ign_resource_path = os.environ.get('IGN_GAZEBO_RESOURCE_PATH', '')
combined_path = f"{model_path}:{gz_resource_path}:{ign_resource_path}"
os.environ['GZ_SIM_RESOURCE_PATH'] = combined_path
os.environ['IGN_GAZEBO_RESOURCE_PATH'] = combined_path
use_sim_time = LaunchConfiguration('use_sim_time', default='true')
headless = LaunchConfiguration('headless', default='false')
# Detect which Gazebo command is available
gz_cmd = get_gazebo_command()
# For ign command, use 'gazebo' subcommand; for gz, use 'sim'
if gz_cmd == 'ign':
sim_cmd = [gz_cmd, 'gazebo', '-r', world_file]
spawn_cmd = [
gz_cmd, 'service', '-s', '/world/drone_landing_world/create',
'--reqtype', 'ignition.msgs.EntityFactory',
'--reptype', 'ignition.msgs.Boolean',
'--timeout', '5000',
'--req', f'sdf_filename: "{drone_model}", name: "drone"'
]
else:
sim_cmd = [gz_cmd, 'sim', '-r', world_file]
spawn_cmd = [
gz_cmd, 'service', '-s', '/world/drone_landing_world/create',
'--reqtype', 'gz.msgs.EntityFactory',
'--reptype', 'gz.msgs.Boolean',
'--timeout', '5000',
'--req', f'sdf_filename: "{drone_model}", name: "drone"'
]
return LaunchDescription([
DeclareLaunchArgument(
'use_sim_time',
default_value='true',
description='Use simulation (Gazebo) clock'
),
DeclareLaunchArgument(
'headless',
default_value='false',
description='Run Gazebo in headless mode (no GUI)'
),
ExecuteProcess(
cmd=sim_cmd,
output='screen',
additional_env={
'GZ_SIM_RESOURCE_PATH': combined_path,
'IGN_GAZEBO_RESOURCE_PATH': combined_path
}
),
ExecuteProcess(
cmd=spawn_cmd,
output='screen'
),
Node(
package='ros_gz_bridge',
executable='parameter_bridge',
name='gz_bridge',
arguments=[
'/drone/cmd_vel@geometry_msgs/msg/Twist@gz.msgs.Twist',
'/model/drone/odometry@nav_msgs/msg/Odometry@gz.msgs.Odometry',
'/drone/imu@sensor_msgs/msg/Imu@gz.msgs.IMU',
'/clock@rosgraph_msgs/msg/Clock@gz.msgs.Clock',
],
parameters=[{'use_sim_time': use_sim_time}],
output='screen'
),
])
if __name__ == '__main__':
print("This is a ROS 2 launch file.")
print()
print("Usage:")
print(" ros2 launch gazebo/launch/drone_landing.launch.py")
print()
print("Or start Gazebo manually:")
gz_cmd = get_gazebo_command()
if gz_cmd == 'ign':
print(" ign gazebo gazebo/worlds/drone_landing.sdf")
else:
print(" gz sim gazebo/worlds/drone_landing.sdf")
print()
print("Then run: python run_gazebo.py")