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Getting Raw Data from Turtlebot Simulator

asked 2013-09-15 18:32:13 -0500

Alkaros gravatar image

updated 2013-09-15 18:48:46 -0500

Currently running the newest version of turtlebot_simultor and everything is running very well on hydro.

I'm working on a project where I'm trying to integrate POMDP with the turtlebot. I'm trying to get the simmulation working with POMDP first before moving to the actual turtlebot while I'm still testing the Policy and Model.

How can I get raw data from the kinect sensor in the simulation. I've seen the point cloud map it can create in rviz which is useful for one part of the project but I currently need a way to extract a depth value for following a target at a set distance. I'd like to write a small script that just listens to the data being output from the sensor node and passes the important data into the policy and then send the move command somehow to the turtlebot.

Eventually this will be used for a tracking and facial recognition project. The aim is to see how the turtlebot will act while following a target with uncertainty. Depth will be important for following from a certain distance (Which is the first goal) and then after that will be the bot moving to see a face that will be run through a facial recognition program. This last goal will require an image output to be scanned.

Does anyone know of a way to achieve something like this? Some form of automated control?


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answered 2013-09-15 22:49:27 -0500

bit-pirate gravatar image

updated 2013-09-16 13:00:22 -0500

Welcome to ROS Answers, Alkaros!

After reading through your question I believe the point cloud is actually what you are looking for. There is already an application in the turtlebot_follower package, which does something similar to what you are trying to achieve. It uses the point cloud generated by the 3D sensor - RViz is not creating the pointcloud, but only visualising it - to track peoples legs in order to follow them. For this the depth information of the point cloud is used.

However, if for other reasons you like to use depth information only, then you should look at the /camera/depth/image_raw ROS topic. Through it you can receive the depth data of the 3D sensor as an image stream.

Hope this helps!

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Should the depth image topic show upin gztopic list?

Alkaros gravatar image Alkaros  ( 2013-09-16 00:03:55 -0500 )edit

It you want it to work on the real robot you should use rostopic list not gztopic list.

tfoote gravatar image tfoote  ( 2013-09-16 07:27:38 -0500 )edit

The mentioned depth image topic is available through ROS.

bit-pirate gravatar image bit-pirate  ( 2013-09-16 13:01:07 -0500 )edit

Excellent, what is the best way to send movement commands. Is it just simply to stick to teleop and have the script that is processing the policy send teleop commands? Sorry if this is a simple question.

Alkaros gravatar image Alkaros  ( 2013-09-16 16:13:33 -0500 )edit

Just let your script send the velocity commands directly. You can get inspiration on how to do that from the [kobuki_keyop]( and [turtlebot_teleop]( packages. And please remember to mark you question as solved, if you're happy.

bit-pirate gravatar image bit-pirate  ( 2013-09-16 16:54:39 -0500 )edit

Should "rosrun image_view image_view image:=/camera/depth/image_raw" Work? It works with the RGB image, the depth image doesn't show anything using that command. Thanks.

Alkaros gravatar image Alkaros  ( 2013-09-16 17:02:24 -0500 )edit

It should. I can see the depth image.

bit-pirate gravatar image bit-pirate  ( 2013-09-16 18:07:18 -0500 )edit

Any clues to why it wouldn't? It just opens up as a pain gray Window. Nothing that I can interpret as actual data in it.

Alkaros gravatar image Alkaros  ( 2013-09-16 18:37:19 -0500 )edit

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Asked: 2013-09-15 18:32:13 -0500

Seen: 1,541 times

Last updated: Sep 16 '13