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How to extract and use laser data from /scan topic in ROS using C++?

asked 2013-04-08 08:17:35 -0500

hesh8 gravatar image

Hi,

How do I subscribe to the /scan topic so that I can store laser scan data in a data structure? We are trying to get the data to use for control loops.

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answered 2013-04-08 23:35:52 -0500

yigit gravatar image

updated 2013-04-08 23:42:29 -0500

Here is an example:

ros::NodeHandle nh;
ros::Subscriber scanSub;

scanSub=nh.subscribe<sensor_msgs::LaserScan>("/scan",10,&AutoExp::processLaserScan,this);

You can implement the callback function however you like

void AutoExp::processLaserScan(const sensor_msgs::LaserScan::ConstPtr& scan){
     //scan->ranges[] are laser readings
     ...
}

Whenever a new laser reading is published to the "/scan" topic, your callback function is called, assuming that nothing goes wrong.

You can always use commands like

rostopic info /scan
rosmsg show sensor_msgs/LaserScan

to have a detailed information about the topic and the message type.

If you read the documentation of the message type, it helps a lot. Here is the link to sensor_msgs/LaserScan Message

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Sorry but I'm struggling with same problem and when I try to compile i recive error: ‘AutoExp’ has not been declared. So which library should i include or which line(s) should i write to declare "AutoExp" ?

Heartfelt thanks.

umut gravatar imageumut ( 2019-02-16 14:03:55 -0500 )edit
0

answered 2013-04-09 06:34:54 -0500

hesh8 gravatar image

Thanks. I figured it out yesterday. Exactly how you explained it!

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could you please share how did you figure that out? what headers did you added? Thanks

Sanat gravatar imageSanat ( 2019-03-01 07:35:45 -0500 )edit

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Asked: 2013-04-08 08:17:35 -0500

Seen: 10,381 times

Last updated: Apr 09 '13