URDF using gazebo

my_display.launch.py

import launch from launch.substitutions import Command, LaunchConfiguration import launch_ros import os def generate_launch_description():     pkg_share = launch_ros.substitutions.FindPackageShare(package='my_pkg_cpp_urdf').find('my_pkg_cpp_urdf')     default_model_path = os.path.join(pkg_share, 'urdf/my_robot_07.urdf')     default_rviz_config_path = os.path.join(pkg_share, 'rviz/urdf_config.rviz')     robot_state_publisher_node = launch_ros.actions.Node(         package='robot_state_publisher',         executable='robot_state_publisher',         parameters=[{'robot_description': Command(['xacro ', LaunchConfiguration('model')])}]     )     joint_state_publisher_node = launch_ros.actions.Node(         package='joint_state_publisher',         executable='joint_state_publisher',         name='joint_state_publisher',         # condition=launch.conditions.UnlessCondition(LaunchConfiguration('gui'))     )     # joint_state_publisher_gui_node = launch_ros.actions.Node(     #     package='joint_state_publisher_gui',     #     executable='joint_state_publisher_gui',     #     name='joint_state_publisher_gui',     #     condition=launch.conditions.IfCondition(LaunchConfiguration('gui'))     # )     rviz_node = launch_ros.actions.Node(         package='rviz2',         executable='rviz2',         name='rviz2',         output='screen',         arguments=['-d', LaunchConfiguration('rvizconfig')],     )     spawn_entity = launch_ros.actions.Node(      package='gazebo_ros',       executable='spawn_entity.py',         arguments=['-entity', 'my_robot', '-topic', 'robot_description'],         output='screen'     )     return launch.LaunchDescription([         # launch.actions.DeclareLaunchArgument(name='gui', default_value='True',         #                                     description='Flag to enable joint_state_publisher_gui'),         launch.actions.DeclareLaunchArgument(name='model', default_value=default_model_path,                                             description='Absolute path to robot urdf file'),         launch.actions.DeclareLaunchArgument(name='rvizconfig', default_value=default_rviz_config_path,                                             description='Absolute path to rviz config file'),         launch.actions.ExecuteProcess(cmd=['gazebo', '--verbose', '-s', 'libgazebo_ros_init.so', '-s', 'libgazebo_ros_factory.so'], output='screen'),         joint_state_publisher_node,         # joint_state_publisher_gui_node,         robot_state_publisher_node,         spawn_entity,         rviz_node     ])

my_robot_07.urdf

<?xml version="1.0"?> <robot name="my_robot" xmlns:xacro="http://ros.org/wiki/xacro">   <!-- Define robot constants -->   <xacro:property name="base_width" value="0.31"/>   <xacro:property name="base_length" value="0.42"/>   <xacro:property name="base_height" value="0.18"/>   <xacro:property name="wheel_radius" value="0.10"/>   <xacro:property name="wheel_width" value="0.04"/>   <xacro:property name="wheel_ygap" value="0.025"/>   <xacro:property name="wheel_zoff" value="0.05"/>   <xacro:property name="wheel_xoff" value="0.12"/>   <xacro:property name="caster_xoff" value="0.14"/>   <!-- Define some commonly used intertial properties  -->   <xacro:macro name="box_inertia" params="m w h d">     <inertial>       <origin xyz="0 0 0" rpy="${pi/2} 0 ${pi/2}"/>             <mass value="${m}"/>       <inertia ixx="${(m/12) * (h*h + d*d)}" ixy="0.0" ixz="0.0" iyy="${(m/12) * (w*w + d*d)}" iyz="0.0" izz="${(m/12) * (w*w + h*h)}"/>     </inertial>   </xacro:macro>   <xacro:macro name="cylinder_inertia" params="m r h">     <inertial>       <origin xyz="0 0 0" rpy="${pi/2} 0 0" />             <mass value="${m}"/>       <inertia ixx="${(m/12) * (3*r*r + h*h)}" ixy = "0" ixz = "0" iyy="${(m/12) * (3*r*r + h*h)}" iyz = "0" izz="${(m/2) * (r*r)}"/>      </inertial>   </xacro:macro>   <xacro:macro name="sphere_inertia" params="m r">     <inertial>       <mass value="${m}"/>       <inertia ixx="${(2/5) * m * (r*r)}" ixy="0.0" ixz="0.0" iyy="${(2/5) * m * (r*r)}" iyz="0.0" izz="${(2/5) * m * (r*r)}"/>     </inertial>   </xacro:macro>      <!-- Robot Base -->   <link name="base_link">     <visual>       <geometry>         <box size="${base_length} ${base_width} ${base_height}"/>       </geometry>       <material name="Cyan">         <color rgba="0 1.0 1.0 1.0"/>       </material>     </visual>     <collision>       <geometry>         <box size="${base_length} ${base_width} ${base_height}"/>       </geometry>     </collision>     <xacro:box_inertia m="15" w="${base_width}" d="${base_length}" h="${base_height}"/>   </link>       <!-- Robot Footprint -->   <link name="base_footprint">    <xacro:box_inertia m="0" w="0" d="0" h="0"/>   </link>   <joint name="base_joint" type="fixed">     <parent link="base_link"/>     <child link="base_footprint"/>     <origin xyz="0.0 0.0 ${-(wheel_radius+wheel_zoff)}" rpy="0 0 0"/>   </joint>   <!-- Wheels -->   <xacro:macro name="wheel" params="prefix x_reflect y_reflect">     <link name="${prefix}_link">       <visual>         <origin xyz="0 0 0" rpy="${pi/2} 0 0"/>         <geometry>             <cylinder radius="${wheel_radius}" length="${wheel_width}"/>         </geometry>         <material name="Gray">           <color rgba="0.5 0.5 0.5 1.0"/>         </material>       </visual>       <collision>         <origin xyz="0 0 0" rpy="${pi/2} 0 0"/>          <geometry>           <cylinder radius="${wheel_radius}" length="${wheel_width}"/>         </geometry>       </collision>       <xacro:cylinder_inertia m="0.5" r="${wheel_radius}" h="${wheel_width}"/>     </link>     <joint name="${prefix}_joint" type="continuous">       <parent link="base_link"/>       <child link="${prefix}_link"/>       <origin xyz="${x_reflect*wheel_xoff} ${y_reflect*(base_width/2+wheel_ygap)} ${-wheel_zoff}" rpy="0 0 0"/>       <axis xyz="0 1 0"/>     </joint>   </xacro:macro>   <xacro:wheel prefix="drivewhl_l" x_reflect="-1" y_reflect="1" />   <xacro:wheel prefix="drivewhl_r" x_reflect="-1" y_reflect="-1" />   <link name="front_caster">     <visual>       <geometry>         <sphere radius="${(wheel_radius+wheel_zoff-(base_height/2))}"/>       </geometry>       <material name="Cyan">         <color rgba="0 1.0 1.0 1.0"/>       </material>     </visual>     <collision>       <origin xyz="0 0 0" rpy="0 0 0"/>       <geometry>         <sphere radius="${(wheel_radius+wheel_zoff-(base_height/2))}"/>       </geometry>     </collision>     <xacro:sphere_inertia m="0.5" r="${(wheel_radius+wheel_zoff-(base_height/2))}"/>   </link>   <joint name="caster_joint" type="fixed">     <parent link="base_link"/>     <child link="front_caster"/>     <origin xyz="${caster_xoff} 0.0 ${-(base_height/2)}" rpy="0 0 0"/>   </joint>   <link name="imu_link">     <visual>       <geometry>         <box size="0.1 0.1 0.1"/>       </geometry>     </visual>          <collision>       <geometry>         <box size="0.1 0.1 0.1"/>       </geometry>     </collision>            <xacro:box_inertia m="0.1" w="0.1" d="0.1" h="0.1"/>   </link>        <joint name="imu_joint" type="fixed">     <parent link="base_link"/>     <child link="imu_link"/>     <origin xyz="0 0 0.01"/>   </joint>        <gazebo reference="imu_link">     <sensor name="imu_sensor" type="imu">       <plugin filename="libgazebo_ros_imu_sensor.so" name="imu_plugin">         <ros>           <namespace>/demo</namespace>           <remapping>~/out:=imu</remapping>         </ros>         <initial_orientation_as_reference>false</initial_orientation_as_reference>       </plugin>       <always_on>true</always_on>       <update_rate>100</update_rate>       <visualize>true</visualize>      <imu>       <angular_velocity>         <x>           <noise type="gaussian">               <mean>0.0</mean>               <stddev>2e-4</stddev>               <bias_mean>0.0000075</bias_mean>               <bias_stddev>0.0000008</bias_stddev>             </noise>           </x>           <y>             <noise type="gaussian">               <mean>0.0</mean>               <stddev>2e-4</stddev>               <bias_mean>0.0000075</bias_mean>               <bias_stddev>0.0000008</bias_stddev>             </noise>           </y>           <z>             <noise type="gaussian">               <mean>0.0</mean>               <stddev>2e-4</stddev>               <bias_mean>0.0000075</bias_mean>               <bias_stddev>0.0000008</bias_stddev>             </noise>           </z>         </angular_velocity>         <linear_acceleration>           <x>             <noise type="gaussian">               <mean>0.0</mean>               <stddev>1.7e-2</stddev>               <bias_mean>0.1</bias_mean>               <bias_stddev>0.001</bias_stddev>             </noise>           </x>           <y>             <noise type="gaussian">               <mean>0.0</mean>               <stddev>1.7e-2</stddev>               <bias_mean>0.1</bias_mean>               <bias_stddev>0.001</bias_stddev>             </noise>           </y>           <z>             <noise type="gaussian">               <mean>0.0</mean>               <stddev>1.7e-2</stddev>               <bias_mean>0.1</bias_mean>               <bias_stddev>0.001</bias_stddev>             </noise>           </z>         </linear_acceleration>       </imu>     </sensor>   </gazebo>     <gazebo>     <plugin name='diff_drive' filename='libgazebo_ros_diff_drive.so'>       <ros>         <namespace>/demo</namespace>       </ros>       <!-- wheels -->       <left_joint>drivewhl_l_joint</left_joint>       <right_joint>drivewhl_r_joint</right_joint>       <!-- kinematics -->       <wheel_separation>0.4</wheel_separation>       <wheel_diameter>0.2</wheel_diameter>       <!-- limits -->       <max_wheel_torque>20</max_wheel_torque>       <max_wheel_acceleration>1.0</max_wheel_acceleration>       <!-- output -->       <publish_odom>true</publish_odom>       <publish_odom_tf>false</publish_odom_tf>       <publish_wheel_tf>true</publish_wheel_tf>       <odometry_frame>odom</odometry_frame>       <robot_base_frame>base_link</robot_base_frame>     </plugin>   </gazebo> </robot>

package.xml

<?xml version="1.0"?> <?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?> <package format="3">   <name>my_pkg_cpp_urdf</name>   <version>0.0.0</version>   <description>TODO: Package description</description>   <maintainer email="ubuntu@todo.todo">ubuntu</maintainer>   <license>TODO: License declaration</license>   <buildtool_depend>ament_cmake</buildtool_depend>   <exec_depend>joint_state_publisher</exec_depend>   <!-- <exec_depend>joint_state_publisher_gui</exec_depend> -->   <exec_depend>robot_state_publisher</exec_depend>   <exec_depend>rviz</exec_depend>   <exec_depend>xacro</exec_depend>   <test_depend>ament_lint_auto</test_depend>   <test_depend>ament_lint_common</test_depend>   <export>     <build_type>ament_cmake</build_type>   </export> </package>

CMakeLists.txt

cmake_minimum_required(VERSION 3.5) project(my_pkg_cpp_urdf) # Default to C99 if(NOT CMAKE_C_STANDARD)   set(CMAKE_C_STANDARD 99) endif() # Default to C++14 if(NOT CMAKE_CXX_STANDARD)   set(CMAKE_CXX_STANDARD 14) endif() if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")   add_compile_options(-Wall -Wextra -Wpedantic) endif() # find dependencies find_package(ament_cmake REQUIRED) # uncomment the following section in order to fill in # further dependencies manually. # find_package(<dependency> REQUIRED) install(   DIRECTORY urdf launch rviz   DESTINATION share/${PROJECT_NAME} ) if(BUILD_TESTING)   find_package(ament_lint_auto REQUIRED)   # the following line skips the linter which checks for copyrights   # uncomment the line when a copyright and license is not present in all source files   #set(ament_cmake_copyright_FOUND TRUE)   # the following line skips cpplint (only works in a git repo)   # uncomment the line when this package is not in a git repo   #set(ament_cmake_cpplint_FOUND TRUE)   ament_lint_auto_find_test_dependencies() endif() ament_package()

 

 

 

Reference

[1] https://navigation.ros.org/setup_guides/odom/setup_odom.html

Setting Up Odometry — Navigation 2 1.0.0 documentation