Cartographer离线建图+仿真建图
1 turtule_bot仿真环境采集数据
启动仿真
加载场景
roslaunch turtlebot3_gazebo turtlebot3_house.launch
更改激光雷达参数后的场景：
roslaunch turtlebot3_gazebo turtlebot3_house_hokuyo.launch
启动可视化仿真
roslaunch turtlebot3_gazebo turtlebot3_gazebo_rviz.launch
启动键盘控制
roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch
rosbag记录数据
记录全部话题
rosbag record -a
记录部分话题
rosbag record /scan /imu /odom
2 cartographer离线建图
目前尚存在问题
3 cartographer在线建图
启动
roslaunch cartographer_ros sim_turtlebot_2d.launch
启动后出现如下警告：
[ WARN] [1587979390.750571170, 567.000000000]: W0427 17:23:10.000000 8793 sensor_bridge.cc:207] Ignored subdivision of a LaserScan message from sensor scan because previous subdivision time 621355973669980000 is not before current subdivision time 621355973669980000
- 修改lua文件中的配置：
num_subdivisions_per_laser_scan = 1
将每个接收到的（多回波）激光扫描分成的点云数。
细分扫描可以在扫描仪移动时取消扫描获取的扫描。
有一个相应的轨迹构建器选项可将细分扫描累积到将用于扫描匹配的点云中。
更改后，以上的报警消失，但是定位效果依然很差！
定位效果差
修改权重参数
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 1.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.translation_weight = 25.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 25.
POSE_GRAPH.optimization_problem.local_slam_pose_translation_weight = 1e4
POSE_GRAPH.optimization_problem.local_slam_pose_rotation_weight = 1e4
POSE_GRAPH.optimization_problem.odometry_translation_weight = 1e4
POSE_GRAPH.optimization_problem.odometry_rotation_weight = 1e4
效果依然不好。
修改gazebo turtlebot3上的激光雷达
在操作过程中遇到问题，修改后雷达无法启动，报错。
[gazebo-2] process has died [pid 1813, exit code 255, cmd /opt/ros/kinetic/lib/gazebo_ros/gzserver -e ode /opt/ros/kinetic/share/turtlebot3_gazebo/worlds/empty.world __name:=gazebo __log:=/home/parobot/.ros/log/1c817030-89c9-11ea-be5e-4074e08fa7fa/gazebo-2.log].
log file: /home/parobot/.ros/log/1c817030-89c9-11ea-be5e-4074e08fa7fa/gazebo-2*.log
在终端执行一下操作可以消除错误
killall gzserver
更改激光雷达
参考博文《ROS总结（三）在仿真模型添加激光雷达》
更改launch文件的中的加载项目
/opt/ros/kinetic/share/turtlebot3_gazebo/launch/turtlebot3_house_hokuyo.launch
更改urdf文件中的加载项
/opt/ros/kinetic/share/turtlebot3_description/urdf/turtlebot3_burger.hokuyo.urdf.xacro
更改gazebo配置文件中的雷达参数
/opt/ros/kinetic/share/turtlebot3_description/urdf/turtlebot3_burger.hokuyo.gazebo.xacro
Gazebo/Blue
0 0 0 0 0 0
$(arg laser_visual)
50
720
1
-2.3550796
2.3550796
0.10
10.0
0.001
gaussian
0.0
0.0005
scan
base_scan
更改激光雷达参数后，定位效果提升一点，还依然很差。
修改lua文件配置参数
TRAJECTORY_BUILDER_2D.use_online_correlative_scan_matching = true
TRAJECTORY_BUILDER_2D.motion_filter.max_time_seconds = 5.
TRAJECTORY_BUILDER_2D.motion_filter.max_distance_meters = 0.1
TRAJECTORY_BUILDER_2D.motion_filter.max_angle_radians = math.rad(0.3)
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 1.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.translation_weight = 25.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 25.
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 = 1e4
POSE_GRAPH.optimization_problem.odometry_rotation_weight = 1e4
修改参数配置
MAP_BUILDER.use_trajectory_builder_2d = true
TRAJECTORY_BUILDER_2D.num_accumulated_range_data = 10
TRAJECTORY_BUILDER_2D.use_imu_data = false
TRAJECTORY_BUILDER_2D.min_range = 0.1
TRAJECTORY_BUILDER_2D.max_range = 8.0
TRAJECTORY_BUILDER_2D.min_z = -0.05
TRAJECTORY_BUILDER_2D.max_z = 0.5
TRAJECTORY_BUILDER_2D.missing_data_ray_length = 10.0
TRAJECTORY_BUILDER_2D.voxel_filter_size = 0.01
TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.max_length = 0.5
TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.min_num_points = 10
TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.max_range = 50.
TRAJECTORY_BUILDER_2D.use_online_correlative_scan_matching = false
TRAJECTORY_BUILDER_2D.motion_filter.max_time_seconds = 5.
TRAJECTORY_BUILDER_2D.motion_filter.max_distance_meters = 0.1
TRAJECTORY_BUILDER_2D.motion_filter.max_angle_radians = math.rad(0.3)
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 1.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.translation_weight = 25.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 25.
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 = 1e4
POSE_GRAPH.optimization_problem.odometry_rotation_weight = 1e4
有所提升，但建图整体效果一般。