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Kobuki base - Jerky move with Nav goal (move_base)

asked 2015-03-16 07:04:13 -0600

sobot gravatar image

updated 2015-03-16 11:17:51 -0600

Hello experts,

I had set up a Turtlebot 2 Kobuki base with ROS indigo Hokuyo lidar, Navigation stack and Gmapping n produce a map from the small area that im working in... all works perfectly and the map is totally consistent, when i move the robot around the room with the Keyop (teleop) but when it comes to publishing a navigation goal or Twist command i have a problem;

  1. i wrote a simple node to publish Twist messages to my Kobuki base with no reaction from the robot until i found out that for the Twist cmds to work with my kobuki I have to send them to /mobile_base/commands/velocity instead of /cmd_vel or do a little remapping for these topics in Kobuki base lauchfiles. long story short, if i dont remap; standard Twist msg dont work, e.g: setting a nav_goal in Rviz for move_base gets no reaction from the robot, etc. but when i remap /cmd_vel to the other topic and then send a goal, my robot acts weird and jumps n snaps (jerky moves) and doesnt seem to stop until i force "ctrl-c" or turn it off. i have no idea what might be problem and found no useful resource on this matter... has anyone faced a similar problem with Kobuki mobile base or have any ideas?
  • ps: tried mapping /mobile_base/commands/velocity to both cmd_vel and cmd_vel_mux and outcome is the same jumpy and sudden moves.

please do ask if u need me to elaborate or send config files.

Thanks!

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answered 2015-03-17 18:18:37 -0600

sobot gravatar image

updated 2015-05-07 15:52:51 -0600

Actually in the Kobuki base model they included a multiplexer to receive & prioritise inputs from different sources, so this is not (wasn't) the problem. problem was that controller_frequency: parameter wasn't right and also a very big X,Y size (meters) for Costmap Local and Global maps in the move_base setting could cause this jerky behaviour. just lower the size to a reasonable amount and it works smooth. (100 x 100; lowered to 40x40 and its all good).

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Just curious what value did you use for the controller_frequency?

jseal gravatar imagejseal ( 2015-04-29 18:24:27 -0600 )edit

@jseal it was set to 4 or 5 if i remember correctly, i raised it to 20 and it worked fine.

sobot gravatar imagesobot ( 2015-05-02 13:48:29 -0600 )edit
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answered 2015-03-17 04:54:44 -0600

AlexR gravatar image

You should not run key teleop and sending navigation goal together. Kill the key teleop shell and then try sending navigation goal. This will not give jerky motion.

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Asked: 2015-03-16 07:04:13 -0600

Seen: 957 times

Last updated: May 07 '15