Attention: Answers.ros.org is deprecated as of August the 11th, 2023. Please visit robotics.stackexchange.com to ask a new question. This site will remain online in read-only mode during the transition and into the foreseeable future. Selected questions and answers have been migrated, and redirects have been put in place to direct users to the corresponding questions on Robotics Stack Exchange. Additional details are available here.

Why is Twist message without timestamp

asked 2012-03-15 21:56:58 -0500

ZdenekM

704 ●29 ●42 ●52

updated 2012-03-15 22:12:16 -0500

Hi,

I'm just wondering - what is the reason for fact, that Twist message has no timestamp?

There is also TwistStamped message type, but as I know it's not commonly used for commanding robots...

Why I'm asking... Because I would like to do some "postprocessing" to data from bag file and because of missing timestamp in cmd_vel topic, I'm not able to precisely compare influence of different commands on robot motion.

edit retag flag offensive close merge delete

add a comment

1 Answer

Sort by » oldest newest most voted

answered 2012-03-15 22:36:40 -0500

This post is a wiki. Anyone with karma >75 is welcome to improve it.

The Twist exists separately of the TwistStamped so that you can compose it into larger messages.

If you're logging the cmd_vel topic you do have the time of receipt, which is not quite perfect. However a timestamp on the velocity command does not have inherent meaning. Is it the time the message was sent? When it should be executed? If so what do you do before or after? And on top of all these questions, adding the header significantly increases the bandwidth usage of this high frequency topic.

edit flag offensive delete link

add a comment

Question Tools

Stats

Asked: 2012-03-15 21:56:58 -0500

Seen: 1,124 times

Last updated: Mar 15 '12

Why is Twist message without timestamp edit

1 Answer

Question Tools

Stats

Related questions

Why is Twist message without timestamp