2.Constructing pose maps

1. Course Content

1.Use slam_toolbox to build raster maps and pose maps

[!NOTE]

• The road network .geojson file must be preceded by at least one raster map.
• Pose maps are designed to enable rapid relocalization during waypoint marking and navigation, improving the accuracy of global positioning and waypoint marking.

2. Building a raster map

• Start the terminal of Humble version of Docker

start_muto_humble

• Terminal input command

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ros2 launch yahboomcar_nav map_slam_toolbox_launch.py

Open RVIZ in a virtual machine or terminal.

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ros2 launch yahboomcar_nav display_nav_launch.py

• Restart the keyboard control node (or use a gamepad).

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ros2 run yahboomcar_ctrl yahboom_keyboard

• Controlling vehicle movement for mapping

• Save raster map

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ros2 service call /slam_toolbox/save_map slam_toolbox/srv/SaveMap "{name: {data: '/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map'}}"

[!TIP]

• nam is used to specify the map name of the saved raster map; in this case, it's road_map.

After execution, we can check if the save was successful (we can see that a road_map.pgm and a road_map.yaml file have been added).

​x
root@raspberrypi:/# ros2 service call /slam_toolbox/save_map slam_toolbox/srv/SaveMap "{name: {data: '/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map'}}"
requester: making request: slam_toolbox.srv.SaveMap_Request(name=std_msgs.msg.String(data='/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map'))
​
response:
slam_toolbox.srv.SaveMap_Response(result=0)
​
root@raspberrypi:/# ll /root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/
total 252
drwxr-xr-x 2 1000 1000   4096 Jan  8 01:53 ./
drwxr-xr-x 9 1000 1000   4096 Jan  4 13:14 ../
-rw-r--r-- 1 root root  22763 Jan  8 01:53 road_map.pgm
-rw-r--r-- 1 root root    125 Jan  8 01:53 road_map.yaml
-rw-r--r-- 1 1000 1000 159459 Jan  4 13:14 test.pgm
-rw-r--r-- 1 1000 1000    181 Jan  4 13:14 test.yaml
-rw-r--r-- 1 1000 1000  51885 Jan  4 13:14 yahboomcar.pgm
-rw-r--r-- 1 1000 1000    126 Jan  4 13:14 yahboomcar.yaml
root@raspberrypi:/#
​

• Save the slam_toolbox pose map

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ros2 service call /slam_toolbox/serialize_map slam_toolbox/srv/SerializePoseGraph "{filename: '/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map'}"

[!TIP]

• map_type stores the map type. The default is gridmap, which stores a raster map. Selecting posegraph stores a pose map, which is a slam_toolbox.

The terminal displays slam_toolbox.srv.SerializePoseGraph_Response(result=0), indicating that the pose map has been successfully saved.

The terminal content is as follows:

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root@raspberrypi:/# ros2 service call /slam_toolbox/serialize_map slam_toolbox/srv/SerializePoseGraph "{filename: '/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map'}"
requester: making request: slam_toolbox.srv.SerializePoseGraph_Request(filename='/root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/road_map')
​
response:
slam_toolbox.srv.SerializePoseGraph_Response(result=0)
​
root@raspberrypi:/# ll /root/yahboomcar_ros2_ws/yahboomcar_ws/src/yahboomcar_nav/maps/                                                                        total 18260
drwxr-xr-x 2 1000 1000     4096 Jan  8 01:54 ./
drwxr-xr-x 9 1000 1000     4096 Jan  4 13:14 ../
-rw-r--r-- 1 root root   157945 Jan  8 01:54 road_map.data
-rw-r--r-- 1 root root    22763 Jan  8 01:53 road_map.pgm
-rw-r--r-- 1 root root 18278895 Jan  8 01:54 road_map.posegraph
-rw-r--r-- 1 root root      125 Jan  8 01:53 road_map.yaml
-rw-r--r-- 1 1000 1000   159459 Jan  4 13:14 test.pgm
-rw-r--r-- 1 1000 1000      181 Jan  4 13:14 test.yaml
-rw-r--r-- 1 1000 1000    51885 Jan  4 13:14 yahboomcar.pgm
-rw-r--r-- 1 1000 1000      126 Jan  4 13:14 yahboomcar.yaml
root@raspberrypi:/#