<joint name="sonar_forward_left_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_forward_left"/>
<joint name="sonar_forward_left_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_forward_left"/>
</joint>
<joint name="sonar_forward_right_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_forward_right"/>
</joint>
<joint name="sonar_forward_right_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_forward_right"/>
</joint>
<joint name="sonar_backward_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_backward"/>
</joint>
<joint name="sonar_backward_joint" type="fixed">
<parent link="mounting_plate"/>
<child link="sonar_backward"/>