with-RL
← 블로그 목록
로봇 / ROS2024년 1월 27일

URDF를 이용한 간단한 로봇 만들기 (1)

URDF(Unified Robot Description Format)는 실제 물리적인 로봇이 아닌 가상환경에서 로봇의 규격을 정의할 수 있는 규칙이라 할 수 있습니다.

URDF는 XML 형식으로 구성되며 ROS 및 Gazebo와 연동하여 가상환경에서 다양한 동작을 실험할 수 있습니다.

이번 포스팅에서는 간단한 URDF를 제작하고 ROS와 연동해서 Rviz에서 확인해 보는 과정입니다.

이 포스트는 다음 영상의 내용을 기반으로 개발하고자 하는 로봇에 적합하게 수정했습니다.

Creating a rough 3D model of our robot with URDF

이 포스트는 다음 과정을 완료한 후에 참고하시길 바랍니다.

1. URDF Package 생성하기

$ cd ~/Workspace/ros_ws/src
$ ros2 pkg create --build-type ament_python urdf_tutorial

2. Simple URDF 만들기

import os
from glob import glob
from setuptools import setup

package_name = 'urdf_tutorial'

setup(
    name=package_name,
    version='0.0.0',
    packages=[package_name],
    data_files=[
        ('share/ament_index/resource_index/packages',
            ['resource/' + package_name]),
        ('share/' + package_name, ['package.xml']),
        (os.path.join('share', package_name, 'launch'), glob('launch/*.launch.py')),
        (os.path.join('share', package_name, 'urdf'), glob('urdf/*.xacro')),
    ],
    install_requires=['setuptools'],
    zip_safe=True,
    maintainer='cchyun',
    maintainer_email='cchyun@todo.todo',
    description='TODO: Package description',
    license='TODO: License declaration',
    tests_require=['pytest'],
    entry_points={
        'console_scripts': [
        ],
    },
)
<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro" name="urdf_test" >

    <!-- BASE -->
    <link name="base_link">
    </link>

    <!-- BODY LINK -->
    <joint name="body_joint" type="fixed">
        <parent link="base_link"/>
        <child link="body"/>
    </joint>

    <link name="body">
        <visual>
            <geometry>
                <box size="1 1 1"/>
            </geometry>
        </visual>
    </link>

</robot>
import os
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.substitutions import LaunchConfiguration
from launch.actions import DeclareLaunchArgument
from launch_ros.actions import Node
import xacro

def generate_launch_description():
    use_sim_time = LaunchConfiguration("use_sim_time")

    pkg_path = os.path.join(get_package_share_directory("urdf_tutorial"))
    xacro_file = os.path.join(pkg_path, "urdf", "robot_1.xacro")
    robot_description = xacro.process_file(xacro_file)
    params = {"robot_description": robot_description.toxml(), "use_sim_time": use_sim_time}

    return LaunchDescription(
        [
            DeclareLaunchArgument(
                "use_sim_time", default_value="false", description="use sim time"
            ),
            Node(
                package="robot_state_publisher",
                executable="robot_state_publisher",
                output="screen",
                parameters=[params],
            ),
        ]
    )
$ cd ~/Workspace/ros_ws
$ colcon build --symlink-install
$ source install/setup.bash
$ ros2 launch urdf_tutorial robot_1.launch.py
$ cd ~/Workspace/ros_ws
$ source install/setup.bash
$ rviz2
$ rqt_graph
<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro" name="urdf_test" >

    <!-- COLOR -->
    <material name="white">
        <color rgba="1 1 1 1" />
    </material>

    <!-- BASE -->
    <link name="base_link">
    </link>

    <!-- BODY LINK -->
    <joint name="body_joint" type="fixed">
        <parent link="base_link"/>
        <child link="body"/>
    </joint>

    <link name="body">
        <visual>
            <geometry>
                <box size="1 1 1"/>
            </geometry>
            <material name="white"/>
        </visual>
    </link>

</robot>
$ cd ~/Worksapce/ros_ws
$ colcon build --symlink-install
$ source install/setup.bash
$ ros2 launch urdf_tutorial robot_1.launch.py
<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro" name="urdf_test" >

    <!-- COLOR -->
    <material name="white">
        <color rgba="1 1 1 1" />
    </material>

    <!-- BASE -->
    <link name="base_link">
    </link>

    <!-- BODY LINK -->
    <joint name="body_joint" type="fixed">
        <parent link="base_link"/>
        <child link="body"/>
    </joint>

    <link name="body">
        <visual>
            <geometry>
                <!-- <box size="1 1 1"/> -->
                <cylinder radius="1" length="0.5"/>
            </geometry>
            <material name="white"/>
        </visual>
    </link>

</robot>
$ cd ~/Worksapce/ros_ws
$ colcon build --symlink-install
$ source install/setup.bash
$ ros2 launch urdf_tutorial robot_1.launch.py
<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro" name="urdf_test" >

    <!-- COLOR -->
    <material name="white">
        <color rgba="1 1 1 1" />
    </material>

    <!-- BASE -->
    <link name="base_link">
    </link>

    <!-- BODY LINK -->
    <joint name="body_joint" type="fixed">
        <parent link="base_link"/>
        <child link="body"/>
    </joint>

    <link name="body">
        <visual>
            <geometry>
                <!-- <box size="1 1 1"/> -->
                <!-- <cylinder radius="1" length="0.5"/> -->
                <sphere radius="1.0"/>
            </geometry>
            <material name="white"/>
        </visual>
    </link>

</robot>
$ cd ~/Worksapce/ros_ws
$ colcon build --symlink-install
$ source install/setup.bash
$ ros2 launch urdf_tutorial robot_1.launch.py
URDF를 이용한 간단한 로봇 만들기 (1) | with-RL