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Hi everyone, I want to get cost value of a specific point in local costmap. For example, i have a point and the position of this point is taken relative to map tf frame. Can you tell me how to check cost value of the point in local costmap of robot ?
Thank you and happy new year !
move_base should be publishing the latest values on a topic named /move_base/local_costmap/costmap. Your ros node should subscribe to this topic.
I would not use costmap_2d class to monitor this data. It is mainly used to create a costmap and apply sensor updates to that costmap.
Hi @N.N.Huy you could access the cost from a specific cell using getCost() function:
unsigned char costmap_2d::Costmap2D::getCost (unsigned int mx, unsigned int my ) const
Get the cost of a cell in the costmap:
Parameters:
mx: The x coordinate of the cell
my: The y coordinate of the cell
Returns: The cost of the cell
It is not working like this. The value is always displaying 0. I think what @Mike mention might be true. Will try that.
Asked: 2022-01-01 23:49:57 -0500
Seen: 615 times
Last updated: Jan 02 '22
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Nice, thank you @Mike Scheutzow and @osilva for your explanations. So I understand as the following steps:
/move_base/local_costmap/costmapgetCost()function as @osilva said.So is the procedure I said above right ? And how can I do the transformation ? Can I use worldtomap to do the transformation?
Take a look at the
nav_msgs/OccupancyGridmessage. It has all the info you need to calculate an index into the cell grid. (0,0) is the lower left corner of the grid. Since each cell value is anint8, cost probably scaled down to range 0-100 - you should verify that.