How to launch multiple arm with single description file? #825
Description
Hi,
I've got a dual-arm system which has 2 UR5 arms fixed on a base. My plan is to run 2 driver in different namespace and control these arms separately with MoveIt2.
Since it is possible that two arm collide with each other or base, I want to wrote a description file include base and both arm so MoveIt can plan a safe path for me. I have done this with ROS1, but I'm not sure if I can do same thing with ROS2.
I followed UniversalRobots/Universal_Robots_ROS2_Description#70 to write the description file, but I'm not so sure about how to launch driver in different namespace. I tried to run ur_control.launch.py twice with different namespace, but it seems only one arm is launched successfully. Here is my launch file.
import os
from ament_index_python.packages import get_package_share_directory
from launch.actions import IncludeLaunchDescription
from launch import LaunchDescription
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.actions import DeclareLaunchArgument, LogInfo
from launch.substitutions import LaunchConfiguration
from launch.actions import GroupAction
from launch_ros.actions import PushRosNamespace
def generate_launch_description():
ur_type = LaunchConfiguration('ur_type')
arm_0_robot_ip = LaunchConfiguration('arm_0_robot_ip')
arm_0_controller_file = LaunchConfiguration('arm_0_controller_file')
arm_0_tf_prefix = LaunchConfiguration('arm_0_tf_prefix')
arm_0_script_command_port = LaunchConfiguration('arm_0_script_command_port')
arm_1_robot_ip = LaunchConfiguration('arm_1_robot_ip')
arm_1_controller_file = LaunchConfiguration('arm_1_controller_file')
arm_1_tf_prefix = LaunchConfiguration('arm_1_tf_prefix')
arm_1_script_command_port = LaunchConfiguration('arm_1_script_command_port')
# # UR specific arguments
ur_type_arg = DeclareLaunchArgument(
"ur_type",
default_value='ur5',
description="Type/series of used UR robot.",
choices=["ur3", "ur3e", "ur5", "ur5e", "ur10", "ur10e", "ur16e", "ur20"],
)
arm_0_robot_ip_arg = DeclareLaunchArgument(
"arm_0_robot_ip",
default_value='192.168.56.3',
description="IP address by which the robot can be reached.",
)
arm_0_controller_file_arg = DeclareLaunchArgument(
"arm_0_controller_file",
default_value="arm_0_ur_controllers.yaml",
description="YAML file with the controllers configuration.",
)
arm_0_tf_prefix_arg = DeclareLaunchArgument(
"arm_0_tf_prefix",
default_value="arm_0_",
description="tf_prefix of the joint names, useful for \
multi-robot setup. If changed, also joint names in the controllers' configuration \
have to be updated.",
)
arm_0_script_command_port_arg = DeclareLaunchArgument(
"arm_0_script_command_port",
default_value="50001",
description="Port that will be opened to forward script commands from the driver to the robot",
)
arm_1_robot_ip_arg = DeclareLaunchArgument(
"arm_1_robot_ip",
default_value='192.168.56.101',
description="IP address by which the robot can be reached.",
)
arm_1_controller_file_arg = DeclareLaunchArgument(
"arm_1_controller_file",
default_value="arm_1_ur_controllers.yaml",
description="YAML file with the controllers configuration.",
)
arm_1_tf_prefix_arg = DeclareLaunchArgument(
"arm_1_tf_prefix",
default_value="arm_1_",
description="tf_prefix of the joint names, useful for \
multi-robot setup. If changed, also joint names in the controllers' configuration \
have to be updated.",
)
arm_1_script_command_port_arg = DeclareLaunchArgument(
"arm_1_script_command_port",
default_value="50006",
description="Port that will be opened to forward script commands from the driver to the robot",
)
ur_launch_dir = get_package_share_directory('ur_robot_driver')
arm_0 = IncludeLaunchDescription(
PythonLaunchDescriptionSource(os.path.join(ur_launch_dir, 'launch', 'ur_control.launch.py')),
launch_arguments={'ur_type': ur_type,
'robot_ip': arm_0_robot_ip,
'controllers_file': arm_0_controller_file,
'tf_prefix': arm_0_tf_prefix,
'script_command_port': arm_0_script_command_port}.items())
arm_0_with_namespace = GroupAction(
actions=[
PushRosNamespace('arm_0'),
arm_0
]
)
arm_1 = IncludeLaunchDescription(
PythonLaunchDescriptionSource(os.path.join(ur_launch_dir, 'launch', 'ur_control.launch.py')),
launch_arguments={'ur_type': ur_type,
'robot_ip': arm_1_robot_ip,
'controllers_file': arm_1_controller_file,
'tf_prefix': arm_1_tf_prefix,
'script_command_port': arm_1_script_command_port
}.items())
arm_1_with_namespace = GroupAction(
actions=[
PushRosNamespace('arm_1'),
arm_1
]
)
return LaunchDescription([
ur_type_arg,
arm_0_robot_ip_arg,
arm_0_controller_file_arg,
arm_0_tf_prefix_arg,
arm_0_script_command_port_arg,
arm_1_robot_ip_arg,
arm_1_controller_file_arg,
arm_1_tf_prefix_arg,
arm_1_script_command_port_arg,
arm_0_with_namespace,
arm_1_with_namespace
])
and I got
[ur_ros2_control_node-12] terminate called after throwing an instance of 'std::system_error'
[ur_ros2_control_node-12] what(): Failed to bind socket for port 50001 to address. Reason: Address already in use: Address already in use
[ur_ros2_control_node-1] [WARN] [1695810663.355767038] [UR_Client_Library:arm_0_]: Connection attempt on port 50001 while maximum number of clients (1) is already connected. Closing connection.
[ur_ros2_control_node-1] [WARN] [1695810663.363975935] [UR_Client_Library:arm_0_]: Connection attempt on port 50004 while maximum number of clients (1) is already connected. Closing connection.
[ur_ros2_control_node-1] [WARN] [1695810663.372521821] [UR_Client_Library:arm_0_]: Connection attempt on port 50005 while maximum number of clients (1) is already connected. Closing connection.
I already set different ports for both arms in description file so this error really confuse me. My description file is here
I hope somebody can give me a instruction about how to fix my launch file or a example of launch multiple arm.
Thank you for reading my issue and help me.