ros2をいれます
(humble , ubuntu22.04)

sudo apt install cmake pkg-config
sudo apt-get install python3 swig
sudo apt-get install python3-pip

mkdir ~/lidar_ws
cd ~/lidar_ws

git clone https://github.com/YDLIDAR/YDLidar-SDK.git
mkdir YDLidar-SDK/build
cd YDLidar-SDK/build
cmake ..
make
sudo make install
cd ../
pip3 install .
cd ~/lidar_ws
mkdir -p ros2_ws/src
cd ros2_ws/src
git clone -b humble https://github.com/YDLIDAR/ydlidar_ros2_driver.git
cd ../
colcon build --symlink-install
source install/setup.bash
echo "source ~/lidar_ws/ros2_ws/install/setup.bash" >> ~/.bashrc
source ~/.bashrc
chmod 0777 src/ydlidar_ros2_driver/startup/*
sudo sh src/ydlidar_ros2_driver/startup/initenv.sh
sudo apt install ros-humble-cartographer 
sudo apt install ros-humble-cartographer-rviz

これでydlidarとcartographerのインストールが終わります

実際にSLAMする前にセンサーのテストをしてみましょう
ここではX4使う想定で行きます。

ファイルアプリを開いて、lidar_ws/ros2_ws/src/ydlidar_ros2_driver/params　へ移動します。
ydlidar.yamlを適当な名前(old.yaml等)に変更します。
X4.yamlをydlidar.yamlへ変更します。
もしportのところがusb担ってなかったら直します

これでX4が使えるようになりました。

ターミナルを2つ開いて、

sudo chmod 777 /dev/ttyUSB0
ros2 launch ydlidar_ros2_driver ydlidar_launch.py

と

rviz2

を起動してください。

rviz2の左下にあるaddから by topic で/scanを選択してください


topicの設定をbest effortにして、sizeやcolorをいじれば...



# やったーーーー！！！

# SLAMします。

そしたら細かい設定やパラメータの設定をしていきます。

lidar_ws/ros2_ws/src/ydlidar_ros2_driverへ移動します

launchないにydlidar_cartographer.launch.py
を作り、以下をコピペします。

import launch
import launch.actions
import launch.substitutions
import launch_ros.actions

from launch import LaunchDescription
from launch_ros.actions import Node
from launch.substitutions import LaunchConfiguration
from ament_index_python.packages import get_package_share_directory
from launch.actions import DeclareLaunchArgument

import os
def generate_launch_description():
    use_sim_time = LaunchConfiguration('use_sim_time', default='false')
    share_dir = get_package_share_directory('ydlidar_ros2_driver')
    rviz_config_file = os.path.join(share_dir, 'config','ydlidar_cartographer.rviz')
    cartographer_config_dir = LaunchConfiguration('cartographer_config_dir', 
                                                    default=os.path.join(share_dir, 'config'))
    configuration_basename = LaunchConfiguration('configuration_basename', default='ydlidar_cartographer.lua')

    resolution = LaunchConfiguration('resolution', default='0.05')
    publish_period_sec = LaunchConfiguration('publish_period_sec', default='1.0')
    return LaunchDescription([

        # Node(package='rviz2',
        #             executable='rviz2',
        #             name='rviz2',
        #             arguments=['-d', rviz_config_file],
        #     ),

        Node(
            ## Configure the TF of the robot to the origin of the map coordinates
            package='tf2_ros',
            executable='static_transform_publisher',
            output='screen',
            arguments=['0.0', '0.0', '0.0', '0.0', '0.0', '0.0', 'base_link', 'laser_frame']
            ),

        Node(
            ## Configure the TF of the robot to the origin of the map coordinates
            # map TF to odom TF
            package='tf2_ros',
            executable='static_transform_publisher',
            namespace='',
            output='screen',
            arguments=['0.0', '0.0', '0.0', '0.0', '0.0', '0.0', 'map', 'odom']
        ),

        Node(
            ## Configure the TF of the robot to the origin of the map coordinates
            # odom TF to base_footprint
            package='tf2_ros',
            executable='static_transform_publisher',
            namespace='',
            output='screen',
            arguments=['0.0', '0.0', '0.0', '0.0', '0.0', '0.0', 'odom', 'base_footprint']
        ),
            
        Node(
            package='cartographer_ros',
            executable='cartographer_node',
            output='log',
            parameters=[{'use_sim_time': use_sim_time}],
            arguments=['-configuration_directory', cartographer_config_dir, '-configuration_basename', configuration_basename],
            remappings=[('odom','rs_t265/odom'),]
            ),
        DeclareLaunchArgument(
            'resolution',
            default_value=resolution,
            description='Resolution of a grid cell in the published occupancy grid'),

        DeclareLaunchArgument(
            'publish_period_sec',
            default_value=publish_period_sec,
            description='OccupancyGrid publishing period'),

        Node(
            package='cartographer_ros',
            executable='cartographer_occupancy_grid_node',
            name='cartographer_occupancy_grid_node',
            parameters=[{'use_sim_time': use_sim_time}],
            arguments=['-resolution', resolution, '-publish_period_sec', publish_period_sec])
    ])

次にconfig内にydlidar_cartographer.luaを...以下略

include "map_builder.lua"
include "trajectory_builder.lua"

options = {
  map_builder = MAP_BUILDER,
  trajectory_builder = TRAJECTORY_BUILDER,
  map_frame = "map",
  tracking_frame = "laser_frame",
  published_frame = "laser_frame",
  odom_frame = "odom",
  provide_odom_frame = false,
  publish_frame_projected_to_2d = false,
  use_odometry = false,
  use_nav_sat = false,
  use_landmarks = false,
  num_laser_scans = 1,
  num_multi_echo_laser_scans = 0,
  num_subdivisions_per_laser_scan = 1,
  num_point_clouds = 0,
  lookup_transform_timeout_sec = 0.2,
  submap_publish_period_sec = 0.05,
  pose_publish_period_sec = 5e-3,
  trajectory_publish_period_sec = 30e-3,
  rangefinder_sampling_ratio = 1.,
  odometry_sampling_ratio = 1.,
  fixed_frame_pose_sampling_ratio = 1.,
  imu_sampling_ratio = 1.,
  landmarks_sampling_ratio = 1.,
}

MAP_BUILDER.use_trajectory_builder_2d = true

TRAJECTORY_BUILDER_2D.min_range = 0.3
TRAJECTORY_BUILDER_2D.max_range = 12.0
TRAJECTORY_BUILDER_2D.missing_data_ray_length = 5.
TRAJECTORY_BUILDER_2D.use_imu_data = false
TRAJECTORY_BUILDER_2D.use_online_correlative_scan_matching = true

POSE_GRAPH.constraint_builder.min_score = 0.65
POSE_GRAPH.constraint_builder.global_localization_min_score = 0.7

POSE_GRAPH.optimization_problem.local_slam_pose_translation_weight = 1e5
POSE_GRAPH.optimization_problem.local_slam_pose_rotation_weight = 1e5
POSE_GRAPH.optimization_problem.odometry_translation_weight = 1e5
POSE_GRAPH.optimization_problem.odometry_rotation_weight = 1e5
POSE_GRAPH.optimization_problem.huber_scale = 1e3

TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 10
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 40

TRAJECTORY_BUILDER_2D.submaps.num_range_data = 120
TRAJECTORY_BUILDER_2D.motion_filter.max_distance_meters = 0.1
TRAJECTORY_BUILDER_2D.motion_filter.max_angle_radians = math.rad(0.2)

return options

これで設定完了です。

lidar_ws/ros2_wsをターミナルでひらいで
bs(colcon build;source install/setup.bash)
します

できたらterm３つ開いて、

ros2 launch ydlidar_ros2_driver ydlidar_launch.py

ros2 launch ydlidar_ros2_driver ydlidar_cartographer.launch.py

rviz2

rviz2で mapと