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Create a clock (datatype/md5sum) for slam_gmapping

asked 2012-03-22 07:08:00 -0600

Torres gravatar image

updated 2012-03-22 07:20:53 -0600

I have managed to do teleoperation, laser scan as well as passing tf to the slam_gmapping node. (As shown in the rxgraph below)

image description

The only thing that is missing now is the "/clock" topic which has a md5sum datatype.

Question: 1) How to create a clock to use slam_gmapping on lego nxt instead of pr2?

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answered 2012-03-22 07:47:09 -0600

Lorenz gravatar image

Why do you need the clock topic? It is only used when the use_sim_time parameter is set to true, otherwise your computer's clock is used. You can find more information here.

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answered 2012-03-22 08:39:02 -0600

Torres gravatar image

updated 2012-03-22 08:46:04 -0600

Hi Lorenz thank you for your prompt reply.

I have tried to remove from the slam_gmapping_pr2.launch file like base on your advise. The /clock topic is not there now. =) Thank you.

Another thing that I'm uncertain is this line in the slam_gmapping_pr2.launch file: <remap from="scan" to="base_scan"/> It does not publish the scan topic to base_scan topic. (As shown below base_scan has no publisher in rxgraph)

image description

So I cheated a little by using: rosrun topic_tools mux base_scan scan

Once I run "rosrun topic_tools mux base_scan scan" the base_scan will receive data from scan but this warning will pop up:

(As shown in the images below) image description

image description

WARN [1332440846.305991431]: MessageFilter target=/odom : Dropped 100.00% of messages so far. Please turn the ros.gmapping.message_notifier rosconsole logger to DEBUG for more information.

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Asked: 2012-03-22 07:08:00 -0600

Seen: 372 times

Last updated: Mar 22 '12