<robot name="target">
    <link name="center">
        <inertial>
            <mass value="0.1" />
            <inertia  ixx=".0016" ixy="0.0"  ixz="0.0"  iyy="0.0016"  iyz="0.0"  izz=".0016" />
        </inertial>
        <visual>
            <origin xyz="0 0 0"/>
            <geometry>
                <sphere radius="0.05" />
            </geometry>
            <material name="hokuyo_orange">
                <color rgba="1. 0. 0. 1"/>
            </material>
        </visual>
    </link>
</robot>