结合ROS利用Google开源的cartographer算法实时室内建图

学着踏实而务实，越努力越幸运。
当一个人有了足够的内涵和物质做后盾，人生就会变得底气十足。
若是美好，叫做精彩，若是糟糕，叫做经历。

Cartographer介绍

google开源中的介绍:
https://opensource.googleblog.com/2016/10/introducing-cartographer.html

ROS版本安装

ROS版本安装 https://google-cartographer-ros.readthedocs.io/en/latest/
里面有个编译完整版的和未编译版本：
链接: https://pan.baidu.com/s/1hWtI2ZH_CZbjNw2vHzSB1w 提取码: sv98
cartographer (亲测可行) 【要翻墙】
https://google-cartographer-ros.readthedocs.io/en/latest/

使用数据集

创客智造中的安装及修改方法：
https://www.ncnynl.com/archives/201801/2230.html
不同SLAM结果对比工具：
官方 https://google-cartographer.readthedocs.io/en/latest/evaluation.html
Cartographer ROS for TurtleBots：
https://google-cartographer-ros-for-turtlebots.readthedocs.io/en/latest/

报错

1.[错误]attempt to index global ‘SPARSE_POSE_GRAPH’ (a nil value)
[原因]SPARSE_POSE_GRAPH was renamed into POSE_GRAPH half a year ago. Please make sure you are running the latest version.
因此，我们在制作lua配置脚本时参考最新的例子

2.运行TB3的包的时候报错：

[FATAL] [1478966491.756783878]: F1113 00:01:31.000000 11761 sensor_bridge.cc:98] Check failed: sensor_to_tracking->translation().norm() < 1e-5 The IMU frame must be colocated with the tracking frame. Transforming linear acceleration into the tracking frame will otherwise be imprecise.

[原因]：IMU的话题虽然能够匹配上，但消息的坐标名字不对。
[解决方案]:打开:

1 2	home/catkin_ws/src/turtlebot3/turtlebot3_slam/ src/flat_world_imu_node.cpp

修改46行的IMU消息header：imu_out.header.frame_id="imu_link";

算法运行

roslaunch turtlebot3_gazebo turtlebot3_house.launch 
roslaunch cartographer_ros cartographer_demo_rplidar.launch
把configuration中的rplidar.lua中的
tracking_frame = "base_scan", --SLAM算法最终的帧（改成你的雷达的帧 rostopic echo /scans）
published_frame = "base_scan", --同上
provide_odom_frame = true,
odom_frame = "odom",

打开rviz 就可看到。关键点就是这里的雷达和里程计的frame对应。

节点依赖

launch文件中加载的节点和配置文件：

<node name="cartographer_node" pkg="cartographer_ros"  
      type="cartographer_node" args="  
          -configuration_directory $(find cartographer_ros)/configuration_files  
          -configuration_basename rplidar.lua"  
      output="screen">

获取cartographer轨迹：

https://github.com/googlecartographer/cartographer_ros/issues/332

结合TB3运行

添加文件：

1 2	cartographer_ws/src/cartographer_ros/cartographer_ros/ configuration_files/rplidar.lua

复制如下代码：

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

options = {
    map_builder = MAP_BUILDER,
    trajectory_builder = TRAJECTORY_BUILDER,
    map_frame = "map",
    tracking_frame = "laser_link"
    published_frame = "laser_link",
    odom_frame = "odom",
    provide_odom_frame = true,
    use_odometry = 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 = 0.3,
    pose_publish_period_sec = 5e-3,
    trajectory_publish_period_sec = 30e-3,

}
MAP_BUILDER.use_trajectory_builder_2d = true
TRAJECTORY_BUILDER_2D.submaps.num_range_data = 35
TRAJECTORY_BUILDER_2D.min_range = 0.3
TRAJECTORY_BUILDER_2D.max_range = 8.
TRAJECTORY_BUILDER_2D.missing_data_ray_length = 1.
TRAJECTORY_BUILDER_2D.use_imu_data = false
TRAJECTORY_BUILDER_2D.use_online_correlative_scan_matching = true
TRAJECTORY_BUILDER_2D.real_time_correlative_scan_matcher.linear_search_window = 0.1
TRAJECTORY_BUILDER_2D.real_time_correlative_scan_matcher.translation_delta_cost_weight = 10.
TRAJECTORY_BUILDER_2D.real_time_correlative_scan_matcher.rotation_delta_cost_weight = 1e-1

SPARSE_POSE_GRAPH.optimization_problem.huber_scale = 1e2
SPARSE_POSE_GRAPH.optimize_every_n_scans = 35
SPARSE_POSE_GRAPH.constraint_builder.min_score = 0.65

return options

添加launch文件：

1 2	cartographer_ws/src/cartographer_ros/cartographer_ros/ launch/cartographer_demo_rplidar.launch

复制如下代码：

<!-- 请复制该文件到cartographer_ros/cartographer_ros/launch中使用 -->

<launch>  
  <param name="/use_sim_time" value="true" />  
  <node name="cartographer_node" pkg="cartographer_ros"  
        type="cartographer_node" args="  
            -configuration_directory $(find cartographer_ros)/configuration_files  
            -configuration_basename rplidar.lua"  
        output="screen">  
    <remap from="scan" to="scan" />  
  </node>  
  <node name="rviz" pkg="rviz" type="rviz" required="true"  
        args="-d $(find cartographer_ros)/configuration_files/demo_2d.rviz" />  
</launch>

重新编译 catkin_make_isolated –install –use-ninja

参考链接：https://google-cartographer-ros.readthedocs.io