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Ignition Gazebo立ち上げ時のオプション

ignを立ち上げ時にいろいろオプションを同時に立ち上げたりする設定がいろいろあるのですが、今回は省略。

ここのリンクを見てください。

ここまでの記載の内容を下記に示す。

world.sdf

<?xml version="1.0" ?>

<sdf version="1.8">

    <world name="car_world">

        <physics name="1ms" type="ignored">

            <max_step_size>0.001</max_step_size>

            <real_time_factor>1.0</real_time_factor>

        </physics>

        <plugin

            filename="ignition-gazebo-physics-system"

            name="ignition::gazebo::systems::Physics">

        </plugin>

        <plugin

            filename="ignition-gazebo-user-commands-system"

            name="ignition::gazebo::systems::UserCommands">

        </plugin>

        <plugin

            filename="ignition-gazebo-scene-broadcaster-system"

            name="ignition::gazebo::systems::SceneBroadcaster">

        </plugin>

        <plugin filename="libignition-gazebo-imu-system.so"

                name="ignition::gazebo::systems::Imu">

        </plugin>

        <plugin

          filename="libignition-gazebo-sensors-system.so"

          name="ignition::gazebo::systems::Sensors">

          <render_engine>ogre2</render_engine>

        </plugin>

        <light type="directional" name="sun">

            <cast_shadows>true</cast_shadows>

            <pose>0 0 10 0 0 0</pose>

            <diffuse>0.8 0.8 0.8 1</diffuse>

            <specular>0.2 0.2 0.2 1</specular>

            <attenuation>

                <range>1000</range>

                <constant>0.9</constant>

                <linear>0.01</linear>

                <quadratic>0.001</quadratic>

            </attenuation>

            <direction>-0.5 0.1 -0.9</direction>

        </light>

        <model name="ground_plane">

            <static>true</static>

            <link name="link">

                <collision name="collision">

                <geometry>

                    <plane>

                    <normal>0 0 1</normal>

                    </plane>

                </geometry>

                </collision>

                <visual name="visual">

                <geometry>

                    <plane>

                    <normal>0 0 1</normal>

                    <size>100 100</size>

                    </plane>

                </geometry>

                <material>

                    <ambient>0.8 0.8 0.8 1</ambient>

                    <diffuse>0.8 0.8 0.8 1</diffuse>

                    <specular>0.8 0.8 0.8 1</specular>

                </material>

                </visual>

            </link>

        </model>

        <model name='vehicle_blue'>     <!-- 変更  <model name='vehicle_blue' canonical_link='chassis'> -->

            <pose relative_to='world'>0 0 0 0 0 0</pose>   <!--the pose is relative to the world by default-->

            <!-- コメントアウト

            <frame name="lidar_frame" attached_to='chassis'>

                <pose>0.8 0 0.5 0 0 0</pose>

            </frame>

            -->

         <link name="base_footprint"/>  <!--追加-->

            <plugin

                filename="libignition-gazebo-diff-drive-system.so"

                name="ignition::gazebo::systems::DiffDrive">

                <left_joint>left_wheel_joint</left_joint>

                <right_joint>right_wheel_joint</right_joint>

                <wheel_separation>1.2</wheel_separation>

                <wheel_radius>0.4</wheel_radius>

                <!-- odom_publish_frequency>1</odom_publish_frequency コメントアウト-->

                <topic>cmd_vel</topic>

            </plugin>

            <!-- Joint state publisherプラグイン追加 -->

            <plugin filename="libignition-gazebo-joint-state-publisher-system.so" 

              name="ignition::gazebo::systems::JointStatePublisher">

              <topic>joint_states</topic>

            </plugin>

            <!-- Global odometerプラグイン追加-->

            <plugin

              filename="ignition-gazebo-odometry-publisher-system"

              name="ignition::gazebo::systems::OdometryPublisher">

              <odom_publish_frequency>50</odom_publish_frequency>

              <odom_topic>/odom</odom_topic>

              <odom_frame>odom</odom_frame>

              <robot_base_frame>base_footprint</robot_base_frame>

              <tf_topic>/odom/tf</tf_topic>

            </plugin>

            <!--chassis をROS 2で使うbase_linkに変更 -->

            <link name='base_link'> <!-- 変更 -->

            <!-- link name='chassis' -->

                <sensor name='gpu_lidar' type='gpu_lidar'>

                    <topic>scan</topic>  <!-- チュートリアルの"lidar"から変更 -->

                    <ignition_frame_id>base_scan</ignition_frame_id> <!-- 追加 -->

                    <!-- pose relative_to='lidar_frame'>0 0 0 0 0 0</pose --> <!-- コメントアウト -->

                    <update_rate>5</update_rate> <!-- 重い場合は遅くしておく -->

                    <ray>

                        <scan>

                            <horizontal>

                                <samples>360</samples>

                                <resolution>1</resolution>

                                <min_angle>-3.14</min_angle>

                                <max_angle>3.14</max_angle>

                            </horizontal>

                            <vertical>

                                <samples>1</samples>

                                <resolution>0.01</resolution>

                                <min_angle>0</min_angle>

                                <max_angle>0</max_angle>

                            </vertical>

                        </scan>

                        <range>

                            <min>0.08</min>

                            <max>10.0</max>

                            <resolution>0.01</resolution>

                        </range>

                    </ray>

                    <always_on>1</always_on>

                    <visualize>true</visualize>

                </sensor>

                <sensor name="imu_sensor" type="imu">

                    <always_on>1</always_on>

                    <update_rate>1</update_rate>

                    <visualize>true</visualize>

                    <topic>imu</topic>

                </sensor>

                <pose relative_to='__model__'>0.5 0 0.4 0 0 0</pose>

                <inertial> <!--inertial properties of the link mass, inertia matix-->

                    <mass>1.14395</mass>

                    <inertia>

                        <ixx>0.095329</ixx>

                        <ixy>0</ixy>

                        <ixz>0</ixz>

                        <iyy>0.381317</iyy>

                        <iyz>0</iyz>

                        <izz>0.476646</izz>

                    </inertia>

                </inertial>

                <visual name='visual'>

                    <geometry>

                        <box>

                            <size>2.0 1.0 0.5</size>

                        </box>

                    </geometry>

                    <!--Color of the link-->

                    <material>

                        <ambient>0.0 0.0 1.0 1</ambient>

                        <diffuse>0.0 0.0 1.0 1</diffuse>

                        <specular>0.0 0.0 1.0 1</specular>

                    </material>

                </visual>

                <collision name='collision'>

                    <geometry>

                        <box>

                            <size>2.0 1.0 0.5</size>

                        </box>

                    </geometry>

                </collision>

            </link>

            <!--Left wheel-->

            <link name='left_wheel'>

                <pose relative_to="base_link">-0.5 0.6 0 -1.5707 0 0</pose> <!--angles are in radian-->

                <inertial>

                    <mass>1</mass>

                    <inertia>

                        <ixx>0.043333</ixx>

                        <ixy>0</ixy>

                        <ixz>0</ixz>

                        <iyy>0.043333</iyy>

                        <iyz>0</iyz>

                        <izz>0.08</izz>

                    </inertia>

                </inertial>

                <visual name='visual'>

                    <geometry>

                        <cylinder>

                            <radius>0.4</radius>

                            <length>0.2</length>

                        </cylinder>

                    </geometry>

                    <material>

                        <ambient>1.0 0.0 0.0 1</ambient>

                        <diffuse>1.0 0.0 0.0 1</diffuse>

                        <specular>1.0 0.0 0.0 1</specular>

                    </material>

                </visual>

                <collision name='collision'>

                    <geometry>

                        <cylinder>

                            <radius>0.4</radius>

                            <length>0.2</length>

                        </cylinder>

                    </geometry>

                </collision>

            </link>

            <!--The same as left wheel but with different position-->

            <link name='right_wheel'>

                <pose relative_to="base_link">-0.5 -0.6 0 -1.5707 0 0</pose> <!--angles are in radian-->

                <inertial>

                    <mass>1</mass>

                    <inertia>

                        <ixx>0.043333</ixx>

                        <ixy>0</ixy>

                        <ixz>0</ixz>

                        <iyy>0.043333</iyy>

                        <iyz>0</iyz>

                        <izz>0.08</izz>

                    </inertia>

                </inertial>

                <visual name='visual'>

                    <geometry>

                        <cylinder>

                            <radius>0.4</radius>

                            <length>0.2</length>

                        </cylinder>

                    </geometry>

                    <material>

                        <ambient>1.0 0.0 0.0 1</ambient>

                        <diffuse>1.0 0.0 0.0 1</diffuse>

                        <specular>1.0 0.0 0.0 1</specular>

                    </material>

                </visual>

                <collision name='collision'>

                    <geometry>

                        <cylinder>

                            <radius>0.4</radius>

                            <length>0.2</length>

                        </cylinder>

                    </geometry>

                </collision>

            </link>

            <!--arbitrary frame-->

            <frame name="caster_frame" attached_to='base_link'>

                <pose>0.8 0 -0.2 0 0 0</pose>

            </frame>

            <!--caster wheel-->

            <link name='caster'>

                <pose relative_to='caster_frame'/>

                <inertial>

                    <mass>1</mass>

                    <inertia>

                        <ixx>0.016</ixx>

                        <ixy>0</ixy>

                        <ixz>0</ixz>

                        <iyy>0.016</iyy>

                        <iyz>0</iyz>

                        <izz>0.016</izz>

                    </inertia>

                </inertial>

                <visual name='visual'>

                    <geometry>

                        <sphere>

                            <radius>0.2</radius>

                        </sphere>

                    </geometry>

                    <material>

                        <ambient>0.0 1 0.0 1</ambient>

                        <diffuse>0.0 1 0.0 1</diffuse>

                        <specular>0.0 1 0.0 1</specular>

                    </material>

                </visual>

                <collision name='collision'>

                    <geometry>

                        <sphere>

                            <radius>0.2</radius>

                        </sphere>

                    </geometry>

                </collision>

            </link>

            <!--left wheel joint-->

            <joint name='left_wheel_joint' type='revolute'>

                <pose relative_to='left_wheel'/>

                <parent>base_link</parent>

                <child>left_wheel</child>

                <axis>

                    <xyz expressed_in='__model__'>0 1 0</xyz> <!--can be descired to any frame or even arbitrary frames-->

                    <limit>

                        <lower>-1.79769e+308</lower>    <!--negative infinity-->

                        <upper>1.79769e+308</upper>     <!--positive infinity-->

                    </limit>

                </axis>

            </joint>

            <!--right wheel joint-->

            <joint name='right_wheel_joint' type='revolute'>

                <pose relative_to='right_wheel'/>

                <parent>base_link</parent>

                <child>right_wheel</child>

                <axis>

                    <xyz expressed_in='__model__'>0 1 0</xyz>

                    <limit>

                        <lower>-1.79769e+308</lower>    <!--negative infinity-->

                        <upper>1.79769e+308</upper>     <!--positive infinity-->

                    </limit>

                </axis>

            </joint>

            <!--caster wheel joint--> <!--pose defult value is the child-->

            <joint name='caster_wheel' type='ball'>

                <parent>base_link</parent>

                <child>caster</child>

            </joint>

        </model>

    </world>

</sdf>

ROS 2との通信

ROS 2にトピックをブリッジしてRviz2で表示できることを確認する。

適当にパッケージを作成する．

cd ~/ros2_ws/src/

ros2 pkg create --build-type ament_cmake sample_ignros

cd sample_ignros

mkdir models

mkdir launch

cd models

mkdir mobilerobot

mkdir worlds

作成したworldに先ほど作成したworld.sdfを保存．

world.sdfにロボットのモデルが含まれてしまっているので，分離する．

world.sdfは<model>のタグの部分をすべて切り取る．

mobilerobotのディレクトリ内にmodel.sddfを作成して先ほど切り取った<model>のタグをペーストする．ただし，下記の<sdf>タグで最初と最後を囲むこと．

<sdf version='1.8'>

  <model>

・・・

  </model>

</sdf>

ディレクトリ構成は下記．

sample_ignros/

    launch/

    models/

        mobilerobot/

            model.sdf

        worlds/

            world.sdf

launchファイルを作成する．

gedit sample_ignros.launch.py