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Confused about getting XV11 laser data into rviz

asked 2013-05-05 16:37:25 -0600

jetdillo gravatar image

updated 2013-05-05 16:39:33 -0600

Okay, so I finally know enough about ROS to totally tie myself up in knots here. I've got my Neato laser up and running and pumping but data to the /scan topic but not seeing anything in rviz.

I'm running Groovy on a Beaglebone w/ Precise LTS (12.04).

I'm running rviz remotely on a separate laptop, also running Groovy on Precise LTS.

I have a Neato LIDAR hooked up to it, running the cwru-ros-pkg XV11 laser driver. rostopic shows the laser successfully publishing to a topic called "/scan":

ubuntu@arm:~$ rostopic list
/rosout
/rosout_agg
/scan
ubuntu@arm:~$

I'm getting data from rostopic echo on both the Beaglebone and the laptop I'm running rviz on:

armadilo@talon:~$ rostopic echo /scan
header: 
  seq: 15555
  stamp: 
    secs: 1367714272
    nsecs: 996305089
  frame_id: neato_laser
angle_min: 0.0
angle_max: 6.28318548203
angle_increment: 0.0174532923847
time_increment: 0.000163100005011
scan_time: 0.0
range_min: 0.0599999986589
range_max: 5.0
ranges: [0.2980000078678131, 0.3059999942779541, 0.3140000104904175, 0.3240000009536743, 0.3330000042915344, 0.34200000762939453, 0.35100001096725464, 0.3610000014305115

But nothing is showing up in rviz.

I'm using the cwru-ros-pkg xv11_laser_driver which publishes to the /scan topic, not sensor_msgs/LaserScan. I'm sure I'm missing a big chunk of something here but am not exactly sure what.

Any help from those who've been able to get data from their XV11 laser into rviz or other parts of the ROS stack would be appreciated.

Thanks! 'dillo

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answered 2013-06-18 06:59:59 -0600

hersh gravatar image

The problem showing the data in RViz was most likely caused by having "fixed frame" in rviz set to the wrong thing. You can see the frame_id in the laser message headers is "neato_laser". RViz either needs to have that as the fixed frame, or it needs TF messages (on topic /tf) being published which show the relationship between the "neato_laser" coordinate frame and the fixed frame. Typically these are specified in a URDF describing the robot's various links and sensors (each with its own coordinate frame name) and published by robot_state_publisher. Then there is "amcl" which does localization which can give the relationship between the robot's base_link and the map. Since "map" is a very common fixed frame to use, that is the default in rviz.

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answered 2013-06-17 18:23:00 -0600

DrBot gravatar image

This refers to the CWRU package for the XV-11 LDS.

I got rviz to work using fixed frame "neato_laser" and topic "scan" I am using a variable voltage regulator to control the speed and the data is intermittent. About a 1/3 of the time I get valid data, and the rest of the time I get noise. Not sure if this is due to a speed control problem, interface or a faulty sensor. It was working much better with Fergie's neato_node but the XV-11 main board stopped talking on the USB.

I built it in Groovy using just 'make' in a ros_workspace. Not sure how Dillo built his, but his data looks much cleaner. I am going to try a becnh vailable power supply to see if that helps.

Procedure:

git clone the cwru package -> make semi-stable, make xv_11_laser_driver. source the setup.bash - check to see that you can find the driver.

roscore

rosrun xv_11_laser_driver neato_laser_publisher -port:=/dev/ttyUSB0

rosrun rviz rviz

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Comments

DrBot - I had the same problem, and fixed this by adding the _firmware_version:=2 parameter, as explained here: http://answers.ros.org/question/60363/neato-laser-scan-shows-impossible-datas-in-rviz/

Kristof gravatar imageKristof ( 2013-12-27 09:32:05 -0600 )edit
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answered 2013-05-06 03:27:40 -0600

joq gravatar image

The topic name is /scan, I expect its message type is sensor_msgs/LaserScan. You can verify that with this command:

$ rostopic type /scan

To display it with rviz, follow these instructions.

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Asked: 2013-05-05 16:37:25 -0600

Seen: 1,171 times

Last updated: Jun 18 '13