How to make a simulation with dwa?

[liunini123]

Hi, I want to compare the simulation results of MPC and DWA.

I completed the simulation with MPC, like this:

But I don't know how to make a simulation with DWA, like the right results in this picture.

[Geonhee-LEE]

Hi, @liunini123 Actually, you should launch the dwa_local_planner in order to use DWA . This repo also supports dummy global_planner plugin. Could you refer to above link?

[liunini123]

I have downloaded the navigation package and add some codes in ref_trajectory_tracking_gazebo.launch.

But the robot didn't move. And the terminal shows like:

Can you tell me in detail how to start move_base in the ref_trajectory_tracking_gazebo.launch. And choose DWA as the local planner?

[liunini123]

Another problem is when I run "roslaunch mpc_ros mpc_local_planner.launch controller:=dwa", the robot always turn right, didn't follow the path.

https://user-images.githubusercontent.com/70358354/155269681-5c09cb39-a39c-4223-babe-d181ae51cc0f.mp4

[Geonhee-LEE]

Hi, @liunini123

Did you change global planner with GeonPlanner? In order to deliver path from dwa_trajectory_generation.py to global planner, you should use GeonPlanner not Global Planner

[Geonhee-LEE]

mpc_local_planner

To get nice DWA performance, parameter tuning is necessary. Why don't you try to change the dwa params?

[liunini123]

Hi, @liunini123

Did you change global planner with GeonPlanner? In order to deliver path from dwa_trajectory_generation.py to global planner, you should use GeonPlanner not Global Planner

I changed the global planner with 'GeonPlanner', then the robot can move. Sometimes, the robot stop moving because path.cost_ < 0 in DWAPlannerROS.

https://user-images.githubusercontent.com/70358354/155880373-18d075ea-3e69-4615-9d8d-8437ed57f72b.mp4

[liunini123]

When I use dwa, global path is displayed in red and local path is displayed in blue in this video. The recorded path is far from global path sometimes. What should I do to make local path near to global path?

https://user-images.githubusercontent.com/70358354/156103323-3feefe12-4023-4a96-b953-ea4ddbfe4068.mp4

[Geonhee-LEE]

When I use dwa, global path is displayed in red and local path is displayed in blue in this video. The recorded path is far from global path sometimes. What should I do to make local path near to global path?

dwa1.mp4

Hi, @liunini123. In order to follow the every poses of geometry shape's path , it should cut with particular interval as local plan. As I remind, _pathLength of global path planner plugin corresponds that I mentioned above. If you want to make better conversion from global to local, I recommend that you consider path's sequence and distance.

[liunini123]

Ok, Thank you! This video is played with dwa.

https://user-images.githubusercontent.com/70358354/156136220-50b83423-61c5-497c-9869-82973b93407a.mp4

[Geonhee-LEE]

@liunini123, you're welcome! Actually, DWA is not a path tracking method but collision avoidance method. Therefore, DWA can't not help avoiding performance decrease in a path tracking experiment. I suggest the pure pursuit and Stanley method can be better control groups about MPC. Finally, please close with comment if you finished your issue.