10. Localization: Launching
Launching
You have your robot, your map, your localization and navigation nodes. Let’s launch it all and test it!
First, launch the simulation:
$ cd /home/workspace/catkin_ws/
$ roslaunch <YOUR PACKAGE NAME> <YOUR WORLD>.launch
In a new terminal, launch the
amcl
launch file:
$ roslaunch <YOUR PACKAGE NAME> amcl.launch
Rviz Configuration
As you did in a previous section, setup your RViz by adding the necessary displays and selecting the required topics to visualize the robot and also the map.
Add by display type
In Rviz,
-
Select
odom
for fixed frame -
Click the “Add” button and
-
add
RobotModel
: this would add the robot itself to RViz -
add
Map
and select firsttopic/map
: the second and third topics in the list will show the global costmap, and the local costmap. Both can be helpful to tune your parameters -
add
PoseArray
and selecttopic/particlecloud
: this will display a set of arrows around the robot
-
add
Each arrow is essentially a particle defining the pose of the robot that your localization package created. Your goal is to add/tune the parameters that will help localize your robot better and thereby improve the pose array.
Note:
You can save the above RViz setup in a configuration file and launch RViz with the same configuration every time. This will make the process more efficient for you! Click
file
->
save config
to save the current configuration.
![](img/screen-shot-2019-01-01-at-9.48.50-pm.png)
Add by topic
When adding elements to RViz, you could also select
By topic
tab. Here, all valid topics would be displayed and you could locate what you need faster!
![](img/screen-shot-2019-01-01-at-9.43.46-pm.png)
Transform Timeout
and
Map Update Loop
If you received warning on
Transform Timeout
and
Map Update Loop
, you might want to configure the corresponding parameters. Namely larger
transform_tolerance
value for the AMCL node and lower
update_frequency
&
publish_frequency
values in the configuration files.