Ask Your Question
1

transform Laser Scan To PointCloud

asked 2011-12-05 22:25:23 -0500

acp gravatar image

updated 2014-01-28 17:10:56 -0500

ngrennan gravatar image

Dear people,

I want to transform laser to point cloud and then see it in rviz.

I have the following code hokuyo_listener_cu.cpp

I have also a tf_broadcaster.cpp that broadcast a transformation from base_link to base_laser.

when I run hokuyo_listener.cpp I get the error:

what(): Frame id /laser does not exist! Frames (3): Frame /base_laser exists with parent /base_link. Frame /base_link exists with parent NO_PARENT.

Here I have difficulties to really interpret the function

transformLaserScanToPointCloud("base_link", *scan, cloud, tfListener_);

1.-How base_link shall be declare?

2.-and how tfListener_ will get the tf transform?

well, maybe are a very basic questions, but well, I dont get it :) any help will be appreciate it :)

edit retag flag offensive close merge delete

Comments

Have you gone through all of the beginner tutorials as well as the tf tutorials?
Eric Perko gravatar imageEric Perko ( 2011-12-05 22:43:21 -0500 )edit
yes mainly of all them, but I cant figure it out, I need help.
acp gravatar imageacp ( 2011-12-05 23:37:30 -0500 )edit

1 Answer

Sort by ยป oldest newest most voted
3

answered 2011-12-05 23:37:13 -0500

DimitriProsser gravatar image

The error that you are getting says that you are trying to perform a transform to/from a frame that does not exist. This is most likely because your laser topic contains a frame_id named "/laser", but your static transform publisher is publishing a transform from "base_laser" instead. You need to make sure that the frame_id on this incoming message is correct.

The string "base_link" in transformLaserScanToPointCloud is the frame_id that you want to transform the cloud into. This is simply declared by you based on what you want to do. There is no default value.

edit flag offensive delete link more

Comments

Hi, In advance thank you for your advise, I made it work now, I can manipulate every single laser ray position and visualize it in ROS.
acp gravatar imageacp ( 2011-12-06 01:55:04 -0500 )edit
@acp: If you try to change "base_link" parameter in transformLaserScanToPointCloud function call with the one with "/" (i mean like this "/base_link"), will there be any difference? is it working as well?
alfa_80 gravatar imagealfa_80 ( 2012-01-24 21:49:05 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2011-12-05 22:25:23 -0500

Seen: 1,820 times

Last updated: Dec 05 '11