jimmycuff's profile - activity

Look at this tutorial: http://www.ros.org/wiki/simulator_gazebo/Tutorials/Gazebo_ROS_API#Apply_Wrenches_to_Links

Can someone point me in the right direction as to how to add torque sensors (or get torque feedback) to each wheel of a robot?

This might be related to this bug. You can check with rosbag info if that is the case for your logfile.

I have two urdf files: one of a robot w/ a front camera and the other of a camera that I have floating in the air as a top view perspective.

The cameras in the xacro files are as follows: (camera.urdf.xacro)

<gazebo reference="camera_optical_frame">
    <sensor:camera name="top_view_camera_sensor">
        <imageSize>640 480</imageSize>
        <imageFormat>R8G8B8</imageFormat>
        <hfov>90</hfov>
        <nearClip>0.01</nearClip>
        <farClip>100</farClip>
        <updateRate>10.0</updateRate>
        <controller:gazebo_ros_camera name="top_camera_controller" plugin="libgazebo_ros_camera.so">
            <alwaysOn>true</alwaysOn>
            <updateRate>10.0</updateRate>
            <imageTopicName>top_view/image_raw</imageTopicName>
            <interface:camera name="top_camera_iface" />
        </controller:gazebo_ros_camera>
    </sensor:camera>
    <turnGravityOff>true</turnGravityOff>
    <material>Gazebo/Blue</material>
</gazebo>

And the one for the robot is similar:

<gazebo reference="base_camera_optical_frame">
    <sensor:camera name="base_camera_sensor">
        <imageSize>640 480</imageSize>
        <imageFormat>R8G8B8</imageFormat>
        <hfov>90</hfov>
        <nearClip>0.01</nearClip>
        <farClip>100</farClip>
        <updateRate>10.0</updateRate>
        <controller:gazebo_ros_camera name="base_camera_controller" plugin="libgazebo_ros_camera.so">
            <alwaysOn>true</alwaysOn>
            <updateRate>20.0</updateRate>
            <imageTopicName>my_robot/camera</imageTopicName>
            <frameName>base_camera_optical_frame</frameName>
        </controller:gazebo_ros_camera>
    </sensor:camera>
    <turnGravityOff>true</turnGravityOff>
    <material>Gazebo/Blue</material>
</gazebo>

When I try and view the "image" of each camera back in rxbag I get images from both cameras in each video. Is something wrong in my setup?

Both cameras display fine during runtime with image_view.

Can someone explain what these coefficients of friction mean? From looking at this tutorial it says that "Here mu1 and mu2 are the friction coefficients of the wheels."

http://www.ros.org/wiki/urdf/Tutorials/UnderstandingPR2URDFGazeboExtension

However, when looking at the PR2 urdf for the wheels these coefficients are fairly large (100.0). That seems extremely high for a coefficient of friction.

The coefficient of rubber on dry concrete is 0.6-0.85 for example.

Thanks in advance!

I'm not quite sure how to display ladar data using rxbag.

I tired to create a plot of sensor_msgs/LaserScan but when I click on "Configure" I get a huge spew of python errors in my terminal:

lot_configure_frame.py", line 313, in traverse
    PlotConfigureFrame.traverse(tree, child, function)
  File "/opt/ros/electric/stacks/visualization/rxbag_plugins/src/rxbag_plugins/plot_configure_frame.py", line 313, in traverse
    PlotConfigureFrame.traverse(tree, child, function)
  File "/opt/ros/electric/stacks/visualization/rxbag_plugins/src/rxbag_plugins/plot_configure_frame.py", line 313, in traverse
    PlotConfigureFrame.traverse(tree, child, function)
  File "/opt/ros/electric/stacks/visualization/rxbag_plugins/src/rxbag_plugins/plot_configure_frame.py", line 313, in traverse
    PlotConfigureFrame.traverse(tree, child, function)
  File "/opt/ros/electric/stacks/visualization/rxbag_plugins/src/rxbag_plugins/plot_configure_frame.py", line 311, in traverse
    if child:
  File "/usr/lib64/python2.7/dist-packages/wx-2.8-gtk2-unicode/wx/_controls.py", line 5055, in __nonzero__
    def __nonzero__(self): return self.IsOk() 
RuntimeError: maximum recursion depth exceeded

Any ideas as to what is wrong? My initial guess is that there are too many points to be displayed from the ladar.

Is there any other (or better) way to display ladar data from a bag file?