Adding ros integrated contact sensors

asked 2014-01-30 06:19:21 -0600

EricSidorov
53 ●5 ●6 ●11

Hello everyone!

I'm building a biped model and I want to add a sensor that detects a collision between its foot and the ground and sends a message to a ROS topic.

The 'Bumper controller' described here sounds pretty much like what I want. But when I try to put the following tag in the .gazebo file:

<gazebo>
  <plugin name="gazebo_ros_bumper_controller" filename="libgazebo_ros_bumper.so">
    <alwaysOn>true</alwaysOn>
    <updateRate>100</updateRate>
    <bumperTopicName>test_bumper</bumperTopicName>
    <frameName>world</frameName>
  </plugin>
</gazebo>

As suggested in the tutorial, I get the following error:

Error [Model.cc:761] Model[bumperbot] is attempting to load a plugin, but detected an incorrect plugin type. Plugin filename[libgazeborosbumper.so] name[gazeborosbumpercontroller]

I ftought it was because I did not specify any link for the sensor, so I tried using:

<gazebo reference='base_link'>

This time I got the message:

Error [parser.cc:697] XML Element[plugin], child of element[link] not defined in SDF. Ignoring.[link]
Error [parser.cc:688] Error reading element <link>
Error [parser.cc:688] Error reading element <model>
Error [parser.cc:348] Unable to read element <sdf>
Error [parser.cc:299] parse as old deprecated model file failed.
Error [World.cc:1469] Unable to read sdf string

I also tried to follow this answer, which suggested using a tag like this:

<sensor:contact name="contact_sensor">
  <geom>base_link_geom</geom>
  <updateRate>20.0</updateRate>
  <controller:gazebo_ros_bumper name="gazebo_ros_bumper_controller" plugin="libgazebo_ros_bumper.so">
      <alwaysOn>true</alwaysOn>
      <updateRate>20.0</updateRate>
      <bumperTopicName>bumper</bumperTopicName>
      <interface:bumper name="bumper_iface" />
  </controller:gazebo_ros_bumper>
</sensor:contact>

This time the xml couldn't even be parsed.

I did manage to add the gazebo contact sensor

<gazebo reference="base_link">
  <sensor type="contact" name="contact">
    <update_rate>100.000000</update_rate>
    <contact>
      <collision>base_link_collision</collision>
      <topic>/contact</topic>
    </contact>
    <plugin name='gazebo_contact' filename='libContactPlugin.so'/>
  </sensor>
</gazebo>

But it publishes to a gazebo topic, not a ROS topic.

Does anyone know what am I doing wrong? I'm using gazebo 1.9.3 and ros-hydro.

P.S: I've noticed the turtlebot has a sensor that does exactly what I want, but I couldn't figure out where to find the plugin which is used there or how to add it to my model.

Thanks in advance!

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4

answered 2014-01-31 13:25:49 -0600

Jim Rothrock

247 ●8 ●12 ●20 http://www.wunderkamme...

Here is an example:

<gazebo reference="gripper">
  <sensor name="gripper_contact_sensor" type="contact">
    <always_on>true</always_on>
    <update_rate>30.0</update_rate>
    <contact>
      <collision>collision</collision>
    </contact>
    <plugin name="gripper_bumper" filename="libgazebo_ros_bumper.so">
      <bumperTopicName>gripper_contact_sensor_state</bumperTopicName>
      <frameName>gripper</frameName>
    </plugin>
  </sensor>
</gazebo>

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answered 2014-04-03 08:30:17 -0600

Gxav
11 ●1 ●2 ●3

So did you get it worked? I am trying to do the same but always get an empty topic when using libgazeborosbumper.so and no topic is generated when using my own plugin. How you create collision name using urdf description? Thank you in advance