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problem with LaserScan in rviz

asked 2015-05-30 07:53:38 -0500

zeinab gravatar image

updated 2015-06-01 17:23:08 -0500

Hi, I have been using a depth_image_to_laserscan node to create a scan topic which I then use in gmapping and amcl. when I visualize the scan topic (even though hz of /scan in almost 30) it drops many messages when used in amcl but works perfectly with gmapping. I have checked the tf tree it is fine and the very same setting which works perfectly with gmapping has problems with amcl. My fixed frame is map in both cases. I tried changing the fixed frame to depth_image for amcl and it solved the problem. But I need to use it for navigation and I need my fixed frame to be /map. Could this be that map is not available at some instances of time and therefore the tf is not available (a message complaining about transform to depth_camera_link is not given is shown under the status of laserScan)? I also get a new error message complaining about canBus : Bus::open: Can not get ibus-daemon's address. But this is always issued but gmapping works fine. I have realized that amcl_pose is only published when I initialize the robot in rviz and apart from that there is nothing published to this topic. I also get this error in rviz for LaserScan for frame [/depth_camera_link]: No transfrom to fixed fram /map. Tf error:[lookup would require extrapolation into the future]

Sorry if it was too long. Thanks in advance for your help.

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Make sure you are sending an initial pose estimate with rviz when using amcl. Also you can edit your question rather than commenting to add information.

William gravatar image William  ( 2015-06-01 15:25:34 -0500 )edit

Thank you for your reply William. I already edited the question. I do send the initialpose to amcl. I have noticed a large delay (0.3 to 0.5) for odom to map tf when running tf_monitor. The odometery of my robot is good and scans also seem to match but amcl fails frequently to do proper localization

zeinab gravatar image zeinab  ( 2015-06-01 17:26:51 -0500 )edit

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answered 2015-06-02 12:49:51 -0500

zeinab gravatar image

So Apparently the delay of \odom to \map was larger than the transform_tolerance of amcl and therefore it was dropping all the late tfs. I increased this parameter in my amcl. launch file and the problem is now solved.

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Asked: 2015-05-30 07:53:38 -0500

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Last updated: Jun 02 '15