Local costmap not published

Hello everyone!

I am currently working in the final project of “ROS Navigation in 5 days”.
But now I am stuck for more than one day in the very same issue.

I can succesfully publish the global costmap, although the resolution of the map is very low, very pixelated (but I am not sure if this is an issue).

My real problem is that local costmap is not being published. I tried to check typos when loading the layers, several different parameters, I checked that my laser scan readings are perfeclty fine, but I still don’t see anything in my local costmap. This leads to the issue “DWA planner failed to produce path.”

Another big problem relates to “map update frequency”. It’s constantly giving me a warning “Map update loop missed its desired rate of 4.0000Hz… the loop actually took 0.xxxx seconds”. I see that when I change “update_frequency” in “costmap_common_params.yaml” it changes the desired rate…but I don’t see how can I change the actual loop duration besides upgrading hardware (which we as students certainly don’t have access and since this is a very simple application, I bet I am making a mistake somewhere). Is there anywhere where I can understand all those “frequency” related stuff (update_frequency, publish_frequency and also controller_frequency)?

Thank you so much for your help!

Any details I need to provide about my code, please just ask me, I really don’t even know where to continue right now…

Hello @andrejpadilha ,

Could you please share here the rosject you are working on so that we can test it and reproduce your error? Please also indicate the steps to follow (command to launch, etc) in order to reproduce the error.


How can I share it? It’s a fork from the " ROS Navigation Real Robot Project" and it won’t let me make it public or share it.

I see, then just download the packages you have created for Navigation (right-click and download) and send them to me at aezquerro@theconstructsim.com. And please indicate also which command/s to use to reproduce the issue.

Thank you! I just sent you an email.

Hello @andrejpadilha ,

You have a couple of errors in your configuration file.

1.- First, you have a typo in the name of the laser observation_source. Initially, you name it rplidar_laser:

observation_sources: rplidar_laser

Then, right below, you use another name for it:

rpilidar_laser: ... (Note the extra “i” added to the name).

2.- Second, you are using the wrong topic name for the laser:

topic: /hokuyo_base/scan

This topic doesn’t exist in your robot, it should be /scan instead.

Hope this helps,

Thank you! Now both global and local costmaps are loading. I even got a successful path planning and navigation, but I still have some problems.

It reports a lot of errors from transforms:
[ INFO] [1639407636.493960293, 80.003000000]: Got new plan
[ERROR] [1639407636.494246981, 80.003000000]: Extrapolation Error: Lookup would require extrapolation -0.034000000s into the future. Requested time 80.000000000 but the latest data is at time 79.966000000, when looking up transform from frame [odom] to frame [map]

[ERROR] [1639407636.494301263, 80.006000000]: Global Frame: odom Plan Frame size 17: map

[ WARN] [1639407636.494345074, 80.006000000]: Could not transform the global plan to the frame of the controller
[ERROR] [1639407636.494400810, 80.006000000]: Could not get local plan
[ INFO] [1639407637.714562498, 80.605000000]: Got new plan
(and then it repeats)

I have set the base frames on the configuration files of the path planning node and AMCL node just like the solution.