DWB local planner problem when an obstacle is detected on the goal

asked 2019-01-23 04:32:01 -0500

Mobile_robot gravatar image

updated 2019-01-24 03:46:17 -0500

Dear all,

I am facing a problem that I do not know how to fix it.

I use the move_base/global_planner as the global_planner and the DWB_local_planner as the local_planner.

In order to have the full control of the trajectory I have divided the trajectory into lany short trajectory by using some WayPoints. As you can see in the following picture, when there is and obstacle on on waypoint, the DWB_local_planner completely stops till the point would be free (the obstacles moves). I have put a very large radius for each waypoints (around 2.5 m) so as you see in the picture, the /move_base/DWBPlannerROS/Global_planner already sends the trajectory to the next Waypoint but the robot completely stops.

By using the TEB_local_planner as the local_planner the problem is solved but I want (for certain reasons) use the DWB_local_planner.

I was wondering if anyone can help me to understand how to fix this problem.

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The first waypoint is the blue arrow and the second waypoint is at the end of the red line?

David Lu gravatar image David Lu  ( 2019-01-24 10:50:44 -0500 )edit

the second one is an other blue arrow on the left (same direction of the red line) which is not in the figure because it is a bit far.

Mobile_robot gravatar image Mobile_robot  ( 2019-01-24 10:54:55 -0500 )edit

How are you sending each new waypoint? move_base_simple/goal ?

David Lu gravatar image David Lu  ( 2019-01-24 14:06:09 -0500 )edit

For our project, we need to control the global_path. As you know better than me, at the current situation of the base_global_planner we can not create a navigation_corridor. Therefore, we made a package beside which create waypoints as temporary Goals with a distance tolerance.

Mobile_robot gravatar image Mobile_robot  ( 2019-01-25 02:51:42 -0500 )edit

In the figure, as you see, I have augmented the acceptable distance to achieve the first WayPoint (I belive 2m) so if the robot will be in the circle of the waypoint it consider as achieving the waypoint (this is why the RED path is already changed through the next WayPoint.

Mobile_robot gravatar image Mobile_robot  ( 2019-01-25 02:53:52 -0500 )edit

So the problem is that if there is an obstacle at the position of a waypoint, the DWB_local_planner slows down and does not achieve to get near the waypoint, and if it gets close to the waypoint it does not consider this as a achieved Goal.

Mobile_robot gravatar image Mobile_robot  ( 2019-01-25 02:58:11 -0500 )edit

That doesn't answer the question. Are you publishing the goals via a particular topic, or using the action server, or something else?

David Lu gravatar image David Lu  ( 2019-01-25 08:33:22 -0500 )edit

Sorry for my late answer, as I am not the person who developed the WayPoint block I will update my question as soon as I go the answer of your question.

Mobile_robot gravatar image Mobile_robot  ( 2019-01-29 09:10:15 -0500 )edit