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Error in the myrobot file.xacro

  • I tried to make a model for 6 wheeled robot.
  • I modified a 4 wheeled robot.xacro file,but when I tried to launch this model on Gazebo,I found the wheels of the robot are separated from the base of the robot.
  • This is the .xacro file :-

<?xml version="1.0"?>


        <robot xmlns:xacro="http://www.ros.org/wiki/xacro" 
                   xmlns:sensor="http://playerstage.sourceforge.net/gazebo /xmlschema/#sensor"
                xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"
                xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"

    name="robot1_xacro">
        <include filename="$(find erratic_description)/urdf/erratic_hokuyo_laser.xacro" />

            <!-- BASE LASER ATTACHMENT -->
            <erratic_hokuyo_laser parent="base_link">
                    <origin xyz="0.18 0 0.11" rpy="0 0 0" />
            </erratic_hokuyo_laser>

        <xacro:property name="length_wheel" value="0.05" />
        <xacro:property name="radius_wheel" value="0.05" />
        <xacro:macro name="default_inertial" params="mass">
                   <inertial>
                           <mass value="${mass}" />
                           <inertia ixx="1.0" ixy="0.0" ixz="0.0"
                                    iyy="1.0" iyz="0.0"
                                    izz="1.0" />
                   </inertial>
        </xacro:macro>

        <link name="base_footprint">
            <visual>
                <geometry>
                        <box size="0.001 0.001 0.001"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0"/>
            </visual>
            <xacro:default_inertial mass="0.0001"/>
        </link>

        <gazebo reference="base_footprint">
            <material>Gazebo/Green</material>
            <turnGravityOff>false</turnGravityOff>
        </gazebo>

        <joint name="base_footprint_joint" type="fixed">
            <origin xyz="0 0 0" />
            <parent link="base_footprint" />
            <child link="base_link" />
        </joint>


        <link name="base_link">
            <visual>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0.05"/>
                <material name="blue">
                    <color rgba="0 0 .8 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="10"/>
        </link>

        <link name="right_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/>
                <material name="black">
                    <color rgba="0 0 0 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="right_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

        <link name="right_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/> -->

                <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="left_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

           <link name="left_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

            <link name="left_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>


     <joint name="base_to_right_wheel1" type="continuous">
       <parent link="base_link"/>
       <child link="right_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
       <axis xyz="0 0 1" />
     </joint>

     <joint name="base_to_right_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="right_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
    </joint>

     <joint name="base_to_right_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="right_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel1" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="left_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
    </joint>

    <joint name="base_to_left_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <gazebo reference="base_link">
            <material>Erratic/BlueBrushedAluminum</material>
     </gazebo>

     <gazebo reference="right_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo>

     <controller:diffdrive_plugin name="differential_drive_controller" plugin="libdiffdrive_plugin.so">
            <alwaysOn>true</alwaysOn>
            <update>100</update>
            <updateRate>100.0</updateRate>
            <leftJoint>base_to_left_wheel3</leftJoint>
            <rightJoint>base_to_right_wheel1</rightJoint>
            <wheelSeparation>0.33</wheelSeparation>
            <wheelDiameter>0.1</wheelDiameter>
            <torque>5</torque>
            <interface:position name="position_iface_0"/>
        <topicName>cmd_vel</topicName>
     </controller:diffdrive_plugin>

    </gazebo>
    </robot>
  • and that is the robot model that appeared in Gazebo. image description

  • So,please how can I solve this error ?? How can I modify this .xacro file to be able to have a 6 wheeled robot model where the 6 wheels are connected to the base of the robot ??

Any help,please ??

  • My distribution is fuerte & I use ubuntu 12.04 .

Error in the myrobot file.xacro

  • I tried to make a model for 6 wheeled robot.
  • I modified a 4 wheeled robot.xacro file,but when I tried to launch this model on Gazebo,I found the wheels of the robot are separated from the base of the robot.
  • This is the .xacro file :-

<?xml version="1.0"?>


        <robot xmlns:xacro="http://www.ros.org/wiki/xacro" 
                   xmlns:sensor="http://playerstage.sourceforge.net/gazebo /xmlschema/#sensor"
                xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"
                xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"

    name="robot1_xacro">
        <include filename="$(find erratic_description)/urdf/erratic_hokuyo_laser.xacro" />

            <!-- BASE LASER ATTACHMENT -->
            <erratic_hokuyo_laser parent="base_link">
                    <origin xyz="0.18 0 0.11" rpy="0 0 0" />
            </erratic_hokuyo_laser>

        <xacro:property name="length_wheel" value="0.05" />
        <xacro:property name="radius_wheel" value="0.05" />
        <xacro:macro name="default_inertial" params="mass">
                   <inertial>
                           <mass value="${mass}" />
                           <inertia ixx="1.0" ixy="0.0" ixz="0.0"
                                    iyy="1.0" iyz="0.0"
                                    izz="1.0" />
                   </inertial>
        </xacro:macro>

        <link name="base_footprint">
            <visual>
                <geometry>
                        <box size="0.001 0.001 0.001"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0"/>
            </visual>
            <xacro:default_inertial mass="0.0001"/>
        </link>

        <gazebo reference="base_footprint">
            <material>Gazebo/Green</material>
            <turnGravityOff>false</turnGravityOff>
        </gazebo>

        <joint name="base_footprint_joint" type="fixed">
            <origin xyz="0 0 0" />
            <parent link="base_footprint" />
            <child link="base_link" />
        </joint>


        <link name="base_link">
            <visual>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0.05"/>
                <material name="blue">
                    <color rgba="0 0 .8 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="10"/>
        </link>

        <link name="right_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/>
                <material name="black">
                    <color rgba="0 0 0 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="right_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

        <link name="right_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/> -->

                <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="left_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

           <link name="left_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

            <link name="left_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>


     <joint name="base_to_right_wheel1" type="continuous">
       <parent link="base_link"/>
       <child link="right_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
       <axis xyz="0 0 1" />
     </joint>

     <joint name="base_to_right_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="right_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
    </joint>

     <joint name="base_to_right_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="right_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel1" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="left_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
    </joint>

    <joint name="base_to_left_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <gazebo reference="base_link">
            <material>Erratic/BlueBrushedAluminum</material>
     </gazebo>

     <gazebo reference="right_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo>

     <controller:diffdrive_plugin name="differential_drive_controller" plugin="libdiffdrive_plugin.so">
            <alwaysOn>true</alwaysOn>
            <update>100</update>
            <updateRate>100.0</updateRate>
            <leftJoint>base_to_left_wheel3</leftJoint>
            <rightJoint>base_to_right_wheel1</rightJoint>
            <wheelSeparation>0.33</wheelSeparation>
            <wheelDiameter>0.1</wheelDiameter>
            <torque>5</torque>
            <interface:position name="position_iface_0"/>
        <topicName>cmd_vel</topicName>
     </controller:diffdrive_plugin>

    </gazebo>
    </robot>
  • and that is the robot model that appeared in Gazebo. image description

  • So,please how can I solve this error ?? How can I modify this .xacro file to be able to have a 6 wheeled robot model where the 6 wheels are connected to the base of the robot ??

Any help,please ??

  • My distribution is fuerte & I use ubuntu 12.04 .

Error in the myrobot file.xacro

  • I tried to make a model for 6 wheeled robot.
  • I modified a 4 wheeled robot.xacro file,but when I tried to launch this model on Gazebo,I found the wheels of the robot are separated from the base of the robot.
  • This is the .xacro file :-

<?xml version="1.0"?>


        <robot xmlns:xacro="http://www.ros.org/wiki/xacro" 
                   xmlns:sensor="http://playerstage.sourceforge.net/gazebo /xmlschema/#sensor"
                xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"
                xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"

    name="robot1_xacro">
        <include filename="$(find erratic_description)/urdf/erratic_hokuyo_laser.xacro" />

            <!-- BASE LASER ATTACHMENT -->
            <erratic_hokuyo_laser parent="base_link">
                    <origin xyz="0.18 0 0.11" rpy="0 0 0" />
            </erratic_hokuyo_laser>

        <xacro:property name="length_wheel" value="0.05" />
        <xacro:property name="radius_wheel" value="0.05" />
        <xacro:macro name="default_inertial" params="mass">
                   <inertial>
                           <mass value="${mass}" />
                           <inertia ixx="1.0" ixy="0.0" ixz="0.0"
                                    iyy="1.0" iyz="0.0"
                                    izz="1.0" />
                   </inertial>
        </xacro:macro>

        <link name="base_footprint">
            <visual>
                <geometry>
                        <box size="0.001 0.001 0.001"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0"/>
            </visual>
            <xacro:default_inertial mass="0.0001"/>
        </link>

        <gazebo reference="base_footprint">
            <material>Gazebo/Green</material>
            <turnGravityOff>false</turnGravityOff>
        </gazebo>

        <joint name="base_footprint_joint" type="fixed">
            <origin xyz="0 0 0" />
            <parent link="base_footprint" />
            <child link="base_link" />
        </joint>


        <link name="base_link">
            <visual>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                    </geometry>
                <origin rpy="0 0 0" xyz="0 0 0.05"/>
                <material name="blue">
                    <color rgba="0 0 .8 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <box size="0.22 0.380 0.085"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="10"/>
        </link>

        <link name="right_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0.15 -0.25"/>
                <material name="black">
                    <color rgba="0 0 0 1"/>
                </material>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="right_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.085 0 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

        <link name="right_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
                <!-- <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/> -->

                <origin rpy="0 1.57075 0" xyz="-0.085 -0.15 -0.25"/>
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>
        </link>

        <link name="left_wheel_1">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

           <link name="left_wheel_2">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 0 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>

            <link name="left_wheel_3">
            <visual>
                    <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                    </geometry>
            <!--    <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25"/> -->
                <origin rpy="0 1.57075 0" xyz="-0.355 -0.15 -0.25" />
                <material name="black"/>
            </visual>
            <collision>
                <geometry>
                        <cylinder length="${length_wheel}" radius="${radius_wheel}"/>
                </geometry>
            </collision>
            <xacro:default_inertial mass="1"/>

        </link>


     <joint name="base_to_right_wheel1" type="continuous">
       <parent link="base_link"/>
       <child link="right_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
       <axis xyz="0 0 1" />
     </joint>

     <joint name="base_to_right_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="right_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
    </joint>

     <joint name="base_to_right_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="right_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel1" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_1"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <joint name="base_to_left_wheel2" type="continuous">
       <axis xyz="0 0 1" />
       <anchor xyz="0 0 0" />
       <limit effort="100" velocity="100" />
       <parent link="base_link"/>
       <child link="left_wheel_2"/>
       <origin rpy="1.5707 0 0" xyz="0.1 0.15 0"/>
    </joint>

    <joint name="base_to_left_wheel3" type="continuous">
       <parent link="base_link"/>
       <axis xyz="0 0 1" />
       <child link="left_wheel_3"/>
       <origin rpy="1.5707 0 0" xyz="-0.1 0.15 0"/>
     </joint>

     <gazebo reference="base_link">
            <material>Erratic/BlueBrushedAluminum</material>
     </gazebo>

     <gazebo reference="right_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="right_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_1">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_2">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo reference="left_wheel_3">
            <material>Erratic/Black</material>
     </gazebo>

     <gazebo>

     <controller:diffdrive_plugin name="differential_drive_controller" plugin="libdiffdrive_plugin.so">
            <alwaysOn>true</alwaysOn>
            <update>100</update>
            <updateRate>100.0</updateRate>
            <leftJoint>base_to_left_wheel3</leftJoint>
            <rightJoint>base_to_right_wheel1</rightJoint>
            <wheelSeparation>0.33</wheelSeparation>
            <wheelDiameter>0.1</wheelDiameter>
            <torque>5</torque>
            <interface:position name="position_iface_0"/>
        <topicName>cmd_vel</topicName>
     </controller:diffdrive_plugin>

    </gazebo>
    </robot>
  • and that is the robot model that appeared in Gazebo. image description

  • So,please how can I solve this error ?? How can I modify this .xacro file to be able to have a 6 wheeled robot model where the 6 wheels are connected to the base of the robot ??

Any help,please ??

  • My distribution is fuerte & I use ubuntu 12.04 .