How to get turtlebot bumps_wheeldrops working in simulation? [closed]

edit

When running the turtlebot in simulation on Electric, I don't see a 'bumps' being properly processed in turtlebot_node/sensor_state 'bumps_wheeldrops'? The robot will hit objects and the cliff sensors actually might change state, but I don't see anything reflected in the 'bumps_wheeldrops' (i.e. it stays at 0). Is there something I'm missing or should I just file a bug report?

To get to this problem I added static objects to simple.world in turtlebot_gazebo like the pasted code below:

 <!-- Enclosure 1 wall 1 left -->
 <model:physical name="enc1_wall1_model">
   <xyz> -1  0   0.25</xyz>
   <rpy>   0.0    0.0    0.0</rpy>
   <static>true</static>
   <body:box name="enc1_wall1_body">
     <geom:box name="enc1_wall1_geom">
       <mesh>default</mesh>
       <size>0.1  2 0.5</size>
       <visual>
         <size>0.1  2 0.5</size>
         <material>Gazebo/PioneerBody</material>
         <mesh>unit_box</mesh>
       </visual>
     </geom:box>
   </body:box>
 </model:physical>

Then launch turtlebot into simulation and drive around.

roslaunch turtlebot_gazebo turtlebot_empty_world.launch
roslaunch turtlebot_teleop keyboard_teleop.launch

In another terminal

rostopic echo /turtlebot_node/sensor_state

Then drive forward straight into static wall and watch for changes in 'bumps_wheeldrops' output. The cliff sensors change state when driving into objects, but not the bump sensor.

Thanks for your help!