<robot name="box">
    <link name="center">
        <inertial>
            <mass value="1.5" />
            <inertia  ixx=".0016" ixy="0.0"  ixz="0.0"  iyy="0.0016"  iyz="0.0"  izz=".0016" />
        </inertial>
        <collision>
            <origin xyz="0 0 0"/>
            <geometry>
                <box size="0.4 0.4 0.4" />
            </geometry>
        </collision>
    </link>
</robot>