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local_costmap global frame

asked 2012-07-25 02:36:33 -0500

pkohout gravatar image

hi, i do not have a odom frame and wanna use a local costmap. my question is what should i use instead ? my tf tree is /map-> Nav -> Base_footprint -> base_stabilized -> base_link i do not have any idea in all tutorials and in the doku the /odom is used... what can i use instead ?

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What is Nav?

Lorenz gravatar image Lorenz  ( 2012-07-25 02:44:15 -0500 )edit

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answered 2012-07-25 02:55:15 -0500

Lorenz gravatar image

The costmap needs to be in a fixed frame, i.e. frames that do not move in the world. Normally, only map and odom are fixed frames and since you do not have odom, using map should be fine.

The reason why odom is used in map is that map can "jump" because of the particle filter based localization algorithm. If that happens, obstacles get sort of blurred because different cells are set in the costmap. Odometry is continuous, i.e. no jumps can happen and the costmap isn't blurred.

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ok thanks, now i understand that all a little bit more. I use hector quadrotor so i do not know what /nav is exactly but i was watching in rviz an /nav is fixed...i do not move with the rest...should i use /nav or /map ? i have read in other questens that /nav is the odom frame ...is this possible ?

pkohout gravatar image pkohout  ( 2012-07-25 03:04:38 -0500 )edit

You should probably read this: http://www.ros.org/reps/rep-0105.html

joq gravatar image joq  ( 2012-07-26 05:47:03 -0500 )edit

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Asked: 2012-07-25 02:36:33 -0500

Seen: 2,690 times

Last updated: Jul 25 '12