ROS Resources: Documentation | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange
Ask Your Question

How to write node for collecting data from P3AT robot

asked 2011-03-24 03:34:49 -0500

Jurica gravatar image

updated 2011-03-24 04:54:35 -0500

Eric Perko gravatar image

I have question. I wish to collect velocity (left and right speed)data from Pioneer 3AT, and for that write node, and that data i want to use for odometry. I ask if someone can me direct on right path. There are some tutorials but i dont know which i need to look. If someone have idea, please to give me some suggestion. Thanks!

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted

answered 2011-03-28 00:55:39 -0500

JKS gravatar image


Both p2os_driver and ROSARIA publish nav_msgs/Odometry on "pose" topic. Therefore, it suffices to subscribe to the "pose" topic and collect Odometry messages.

If you really need left and right wheel velocities, you should use specific robot parameters and get those speeds from linear and angular velocities that are reported in the Odometry message.

Just one more note, ROSARIA reported Pose in [mm] prior to Feb 24, 2011. As of that date, we've fixed it to report Pose in [m].

edit flag offensive delete link more


Looking at the rosaria package summary it seems that you only have access to the estimated robot velocities but not the joint (the wheels) velocities. Am I missing something? Are these the actual measured encoder counts mapped through the kinematics or are they just the commanded robot velocities? gravatar image  ( 2015-09-22 22:29:07 -0500 )edit

The robot controller (dedicated microcontroller inside the robot) is already doing the integration of the wheel encoders and providing the pose (x,y,th). (You can request encoder counts using ARIA library but this is provided mainly as a diagnostic/testing feature.)

ReedHedges gravatar image ReedHedges  ( 2015-09-24 16:35:03 -0500 )edit

Hello! I am a very new beginner. I have a question: can I control the velocity of wheels on each side individually?

josephtranminh1996 gravatar image josephtranminh1996  ( 2017-07-11 22:23:56 -0500 )edit

Question Tools

1 follower


Asked: 2011-03-24 03:34:49 -0500

Seen: 694 times

Last updated: Mar 28 '11