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Dear all.

I have a differential mobile robot and I am successfuly using SBPLLatticePlanner as a global planner as part of the navigation stack. I tested the robot with :

base_global_planner: SBPLLatticePlanner

base_local_planner: dwa_local_planner/DWAPlannerROS

SBPLLatticePlanner:
   allocated_time: 10
   initial_epsilon: 15.0
   lethal_obstacle: 20.0

And I also tested the robot by commenting out # base_local_planner: dwa_local_planner/DWAPlannerROS

I am using genmprim_unicycle.m to generate motion primitives.

I have experience some issues.

1.- When I comment out base_local_planner: dwa_local_planner/DWAPlannerROS and then I set the goal behind the robot from the current position, the robot does not turn back towards the goal. It starts shaking left-right instead.

2.-The robot does not follow the path close enough, meaning that in crashes with obstacles even though I have set inflation_radius accordingly to the footprint of the robot.

The questions are:

1 .- Is there any local base planner that must be use together with SBPLLatticePlanner.

2.- Which parameters I need to tune or set in order for the robot to turn back when I set the goal behind it?

In advance thank you for your replay.


Originally posted by acp on ROS Answers with karma: 556 on 2014-06-17

Post score: 0

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1 Answer 1

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For (1) you can use either local planner (DWA or Trajectory Rollout) -- but you will almost certainly have to tune it for your robot. If you haven't supplied velocity and acceleration limits for your local planner, you will likely not get good results. See the Local Planner section of the Basic Navigation Tuning Tutorial for a list of things you probably want to tune.

For (2), you might have to come up with new motion primitives -- I'm not sure if the default ones include turning in place. I would certainly visualize the local and global plans in RVIZ though to be sure of which planner is actually not getting you to your goal.


Originally posted by fergs with karma: 13902 on 2014-06-20

This answer was ACCEPTED on the original site

Post score: 0


Original comments

Comment by acp on 2014-06-30:
Hi, thank you very much for your answer, I have solved the issues with unicycleplussidewaysplusbackturn.mprim, however I have another issue, Sometimes it get stuck when it gets trap in inflated obstacles even though there is enough space around the robot.

I found the package sbpl_recovery in this site thttps://github.com/ros-planning/navigation_experimental/tree/hydro-devel/sbpl_recovery hat I think it could help to recover when the robot gets trap. But the package does compile under Hydro due to changes in costmap2d. Or is there some other solution.

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