fic comment

diff --git a/urdf/a4wd3.urdf b/urdf/a4wd3.urdf
index 9bb31b8feb9dc5543cdba989bab89766a2fda322..b17e62272e3de9ea065a01d4e5783cd7730660f3 100644 (file)
--- a/urdf/a4wd3.urdf
+++ b/urdf/a4wd3.urdf
@@ -51,9 +51,10 @@
 
   <!-- base_footprint: planar frame at GROUND level (wheel contact), for 2D navigation.
        Wheels dia 158 mm -> rolling radius 79 mm below the axle plane (= base_link origin).
-       Child of base_link (NOT parent): hw_node publishes /odom with child_frame_id
-       base_link and the EKF broadcasts odom->base_link, so base_link must stay the
-       odometry-attached frame; the footprint hangs 79 mm below it. -->
+       PARENT of base_link (inverted 2026-10-13): the launch sets enable_odom_tf=False on
+       hw_node, so nothing else claims the odom->* edge; the EKF (base_link_frame:
+       base_footprint) broadcasts odom->base_footprint and this static joint completes
+       the tree: map -> odom -> base_footprint -> base_link. -->
   <joint name="base_footprint_to_base_link" type="fixed">
     <parent link="base_footprint"/>
     <child link="base_link"/>