(02)Cartographer源码无死角解析-(06) 参数详解与备注→调参查阅使用

本人讲解关于slam一系列文章汇总链接:史上最全slam从零开始，针对于本栏目讲解(02)Cartographer源码无死角解析-接如下:
(02)Cartographer源码无死角解析- (00)目录_最新无死角讲解：https://blog.csdn.net/weixin_43013761/article/details/127350885
 
$文末正下方中心提供了本人联系方式，点击本人照片即可显示WX\to 官方认证$
 

一、前言

通过上篇博客，对 Cartographer 中常见的低级错误进行了介绍，接下来我们需要去深刻的理解一下 Cartographer 中的参数了，主要讲解的时如下几个文件：

src/cartographer_ros/cartographer_ros/configuration_files/lx_rs16_2d_outdoor.lua
src/cartographer/configuration_files/map_builder.lua
src/cartographer/configuration_files/trajectory_builder.lua
src/cartographer/configuration_files/trajectory_builder_2d.lua
src/cartographer/configuration_files/trajectory_builder_3d.lua
src/cartographer/configuration_files/pose_graph.lua

如果查看lx_rs16_2d_outdoor.lua文件，可以看到存在如下代码：

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

其用法和c++可以做类比，就是把 map_builder.lua 与 trajectory_builder.lua 中的配置都都加载到 lx_rs16_2d_outdoor.lua 之中。

另外在 lx_rs16_2d_outdoor.lua 中还可以看到

options = {
	......
}

其内部的参数，一般来说都是新的，也就是不不被 map_builder.lua 与 trajectory_builder.lua 包括的。如果在 lx_rs16_2d_outdoor.lua 想要修改 map_builder.lua 或者 trajectory_builder.lua 中的参数，应该如何操作呢？其实比较建档，如 lx_rs16_2d_outdoor.lua 中的如下语句：

TRAJECTORY_BUILDER_2D.use_imu_data = true
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 1.

就是对 TRAJECTORY_BUILDER_2D 中文件的修改， trajectory_builder.lua 中包含了 trajectory_builder_2d.lua 与 trajectory_builder_3d.lua，trajectory_builder.lua 的内容十分简单如下：

include "trajectory_builder_2d.lua"
include "trajectory_builder_3d.lua"

TRAJECTORY_BUILDER = {
  trajectory_builder_2d = TRAJECTORY_BUILDER_2D,
  trajectory_builder_3d = TRAJECTORY_BUILDER_3D,
--  pure_localization_trimmer = {
--    max_submaps_to_keep = 3,
--  },
  collate_fixed_frame = true,
  collate_landmarks = false,
}

下面对是常用的配置文件做的注释
 

二、lx_rs16_2d_outdoor.lua

改文件位于 src/cartographer_ros/cartographer_ros/configuration_files/lx_rs16_2d_outdoor.lua：

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

options = {
  map_builder = MAP_BUILDER,                -- map_builder.lua的配置信息
  trajectory_builder = TRAJECTORY_BUILDER,  -- trajectory_builder.lua的配置信息
  
  map_frame = "map",                        -- 地图坐标系的名字
  tracking_frame = "imu_link",              -- 将所有传感器数据转换到这个坐标系下
  published_frame = "odom",            -- tf: map -> footprint
  odom_frame = "odom",                      -- 里程计的坐标系名字
  provide_odom_frame = true,               -- 是否提供odom的tf, 如果为true,则tf树为map->odom->footprint
                                            -- 如果为false tf树为map->footprint
  publish_frame_projected_to_2d = false,    -- 是否将坐标系投影到平面上
  --use_pose_extrapolator = false,            -- 发布tf时是使用pose_extrapolator的位姿还是前端计算出来的位姿

  use_odometry = false,                     -- 是否使用里程计,如果使用要求一定要有odom的tf
  use_nav_sat = false,                      -- 是否使用gps
  use_landmarks = false,                    -- 是否使用landmark
  num_laser_scans = 0,                      -- 是否使用单线激光数据
  num_multi_echo_laser_scans = 0,           -- 是否使用multi_echo_laser_scans数据
  num_subdivisions_per_laser_scan = 1,      -- 1帧数据被分成几次处理,一般为1
  num_point_clouds = 1,                     -- 是否使用点云数据
  
  lookup_transform_timeout_sec = 0.2,       -- 查找tf时的超时时间
  submap_publish_period_sec = 0.3,          -- 发布数据的时间间隔
  pose_publish_period_sec = 5e-3,
  trajectory_publish_period_sec = 30e-3,

  rangefinder_sampling_ratio = 1.,          -- 传感器数据的采样频率
  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.use_imu_data = true
TRAJECTORY_BUILDER_2D.min_range = 0.3
TRAJECTORY_BUILDER_2D.max_range = 100.
TRAJECTORY_BUILDER_2D.min_z = 0.2
--TRAJECTORY_BUILDER_2D.max_z = 1.4
--TRAJECTORY_BUILDER_2D.voxel_filter_size = 0.02

--TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.max_length = 0.5
--TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.min_num_points = 200.
--TRAJECTORY_BUILDER_2D.adaptive_voxel_filter.max_range = 50.

--TRAJECTORY_BUILDER_2D.loop_closure_adaptive_voxel_filter.max_length = 0.9
--TRAJECTORY_BUILDER_2D.loop_closure_adaptive_voxel_filter.min_num_points = 100
--TRAJECTORY_BUILDER_2D.loop_closure_adaptive_voxel_filter.max_range = 50.

TRAJECTORY_BUILDER_2D.use_online_correlative_scan_matching = false
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 1.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.translation_weight = 1.
TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 1.
--TRAJECTORY_BUILDER_2D.ceres_scan_matcher.ceres_solver_options.max_num_iterations = 12

--TRAJECTORY_BUILDER_2D.motion_filter.max_distance_meters = 0.1
--TRAJECTORY_BUILDER_2D.motion_filter.max_angle_radians = 0.004
--TRAJECTORY_BUILDER_2D.imu_gravity_time_constant = 1.

TRAJECTORY_BUILDER_2D.submaps.num_range_data = 80.
TRAJECTORY_BUILDER_2D.submaps.grid_options_2d.resolution = 0.1

POSE_GRAPH.optimize_every_n_nodes = 160.
POSE_GRAPH.constraint_builder.sampling_ratio = 0.3
POSE_GRAPH.constraint_builder.max_constraint_distance = 15.
POSE_GRAPH.constraint_builder.min_score = 0.48
POSE_GRAPH.constraint_builder.global_localization_min_score = 0.60

return options

不再 options 中的参数是一些可能经常需要修改的，写在这里是对前面进行覆盖，方便配置。
 

三、trajectory_builder_2d.lua

文件位于 src/cartographer/configuration_files/trajectory_builder_2d.lua

TRAJECTORY_BUILDER_2D = {
  use_imu_data = true,
  min_range = 0.,
  max_range = 30.,
  min_z = -0.8,
  max_z = 2.,
  missing_data_ray_length = 5.,
  num_accumulated_range_data = 1,
  voxel_filter_size = 0.025,

  adaptive_voxel_filter = {
    max_length = 0.5,
    min_num_points = 200,
    max_range = 50.,
  },

  loop_closure_adaptive_voxel_filter = {
    max_length = 0.9,
    min_num_points = 100,
    max_range = 50.,
  },

  use_online_correlative_scan_matching = false,
  real_time_correlative_scan_matcher = {
    linear_search_window = 0.1,
    angular_search_window = math.rad(20.),
    translation_delta_cost_weight = 1e-1,
    rotation_delta_cost_weight = 1e-1,
  },

  ceres_scan_matcher = {
    occupied_space_weight = 1.,
    translation_weight = 10.,
    rotation_weight = 40.,
    ceres_solver_options = {
      use_nonmonotonic_steps = false,
      max_num_iterations = 20,
      num_threads = 1,
    },
  },

  motion_filter = {
    max_time_seconds = 5.,
    max_distance_meters = 0.2,
    max_angle_radians = math.rad(1.),
  },

  -- TODO(schwoere,wohe): Remove this constant. This is only kept for ROS.
  imu_gravity_time_constant = 10.,
  pose_extrapolator = {
    use_imu_based = false,
    constant_velocity = {
      imu_gravity_time_constant = 10.,
      pose_queue_duration = 0.001,
    },
    imu_based = {
      pose_queue_duration = 5.,
      gravity_constant = 9.806,
      pose_translation_weight = 1.,
      pose_rotation_weight = 1.,
      imu_acceleration_weight = 1.,
      imu_rotation_weight = 1.,
      odometry_translation_weight = 1.,
      odometry_rotation_weight = 1.,
      solver_options = {
        use_nonmonotonic_steps = false;
        max_num_iterations = 10;
        num_threads = 1;
      },
    },
  },

  submaps = {
    num_range_data = 90,
    grid_options_2d = {
      grid_type = "PROBABILITY_GRID",
      resolution = 0.05,
    },
    range_data_inserter = {
      range_data_inserter_type = "PROBABILITY_GRID_INSERTER_2D",
      probability_grid_range_data_inserter = {
        insert_free_space = true,
        hit_probability = 0.55,
        miss_probability = 0.49,
      },
      tsdf_range_data_inserter = {
        truncation_distance = 0.3,
        maximum_weight = 10.,
        update_free_space = false,
        normal_estimation_options = {
          num_normal_samples = 4,
          sample_radius = 0.5,
        },
        project_sdf_distance_to_scan_normal = true,
        update_weight_range_exponent = 0,
        update_weight_angle_scan_normal_to_ray_kernel_bandwidth = 0.5,
        update_weight_distance_cell_to_hit_kernel_bandwidth = 0.5,
      },
    },
  },
}

 

四、trajectory_builder_3d.lua

文件位于 src/cartographer/configuration_files/trajectory_builder_3d.lua

MAX_3D_RANGE = 60.
INTENSITY_THRESHOLD = 40

TRAJECTORY_BUILDER_3D = {
  min_range = 1.,
  max_range = MAX_3D_RANGE,
  num_accumulated_range_data = 1,
  voxel_filter_size = 0.15,

  high_resolution_adaptive_voxel_filter = {
    max_length = 2.,
    min_num_points = 150,
    max_range = 15.,
  },

  low_resolution_adaptive_voxel_filter = {
    max_length = 4.,
    min_num_points = 200,
    max_range = MAX_3D_RANGE,
  },

  use_online_correlative_scan_matching = false,
  real_time_correlative_scan_matcher = {
    linear_search_window = 0.15,
    angular_search_window = math.rad(1.),
    translation_delta_cost_weight = 1e-1,
    rotation_delta_cost_weight = 1e-1,
  },

  ceres_scan_matcher = {
    occupied_space_weight_0 = 1.,
    occupied_space_weight_1 = 6.,
    intensity_cost_function_options_0 = {
        weight = 0.5,
        huber_scale = 0.3,
        intensity_threshold = INTENSITY_THRESHOLD,
    },
    translation_weight = 5.,
    rotation_weight = 4e2,
    only_optimize_yaw = false,
    ceres_solver_options = {
      use_nonmonotonic_steps = false,
      max_num_iterations = 12,
      num_threads = 1,
    },
  },

  motion_filter = {
    max_time_seconds = 0.5,
    max_distance_meters = 0.1,
    max_angle_radians = 0.004,
  },

  rotational_histogram_size = 120,

  -- TODO(schwoere,wohe): Remove this constant. This is only kept for ROS.
  imu_gravity_time_constant = 10.,
  pose_extrapolator = {
    use_imu_based = false,
    constant_velocity = {
      imu_gravity_time_constant = 10.,
      pose_queue_duration = 0.001,
    },
    -- TODO(wohe): Tune these parameters on the example datasets.
    imu_based = {
      pose_queue_duration = 5.,
      gravity_constant = 9.806,
      pose_translation_weight = 1.,
      pose_rotation_weight = 1.,
      imu_acceleration_weight = 1.,
      imu_rotation_weight = 1.,
      odometry_translation_weight = 1.,
      odometry_rotation_weight = 1.,
      solver_options = {
        use_nonmonotonic_steps = false;
        max_num_iterations = 10;
        num_threads = 1;
      },
    },
  },

  submaps = {
    high_resolution = 0.10,
    high_resolution_max_range = 20.,
    low_resolution = 0.45,
    num_range_data = 160,
    range_data_inserter = {
      hit_probability = 0.55,
      miss_probability = 0.49,
      num_free_space_voxels = 2,
      intensity_threshold = INTENSITY_THRESHOLD,
    },
  },

  -- When setting use_intensities to true, the intensity_cost_function_options_0
  -- parameter in ceres_scan_matcher has to be set up as well or otherwise
  -- CeresScanMatcher will CHECK-fail.
  use_intensities = false,
}

 

五、pose_graph.lua

该文件位于 src/cartographer/configuration_files/pose_graph.lua

POSE_GRAPH = {
  optimize_every_n_nodes = 90,
  constraint_builder = {
    sampling_ratio = 0.3,
    max_constraint_distance = 15.,
    min_score = 0.55,
    global_localization_min_score = 0.6,
    loop_closure_translation_weight = 1.1e4,
    loop_closure_rotation_weight = 1e5,
    log_matches = true,
    fast_correlative_scan_matcher = {
      linear_search_window = 7.,
      angular_search_window = math.rad(30.),
      branch_and_bound_depth = 7,
    },
    ceres_scan_matcher = {
      occupied_space_weight = 20.,
      translation_weight = 10.,
      rotation_weight = 1.,
      ceres_solver_options = {
        use_nonmonotonic_steps = true,
        max_num_iterations = 10,
        num_threads = 1,
      },
    },
    fast_correlative_scan_matcher_3d = {
      branch_and_bound_depth = 8,
      full_resolution_depth = 3,
      min_rotational_score = 0.77,
      min_low_resolution_score = 0.55,
      linear_xy_search_window = 5.,
      linear_z_search_window = 1.,
      angular_search_window = math.rad(15.),
    },
    ceres_scan_matcher_3d = {
      occupied_space_weight_0 = 5.,
      occupied_space_weight_1 = 30.,
      translation_weight = 10.,
      rotation_weight = 1.,
      only_optimize_yaw = false,
      ceres_solver_options = {
        use_nonmonotonic_steps = false,
        max_num_iterations = 10,
        num_threads = 1,
      },
    },
  },
  matcher_translation_weight = 5e2,
  matcher_rotation_weight = 1.6e3,
  optimization_problem = {
    huber_scale = 1e1,
    acceleration_weight = 1.1e2,
    rotation_weight = 1.6e4,
    local_slam_pose_translation_weight = 1e5,
    local_slam_pose_rotation_weight = 1e5,
    odometry_translation_weight = 1e5,
    odometry_rotation_weight = 1e5,
    fixed_frame_pose_translation_weight = 1e1,
    fixed_frame_pose_rotation_weight = 1e2,
    fixed_frame_pose_use_tolerant_loss = false,
    fixed_frame_pose_tolerant_loss_param_a = 1,
    fixed_frame_pose_tolerant_loss_param_b = 1,
    log_solver_summary = false,
    use_online_imu_extrinsics_in_3d = true,
    fix_z_in_3d = false,
    ceres_solver_options = {
      use_nonmonotonic_steps = false,
      max_num_iterations = 50,
      num_threads = 7,
    },
  },
  max_num_final_iterations = 200,
  global_sampling_ratio = 0.003,
  log_residual_histograms = true,
  global_constraint_search_after_n_seconds = 10.,
  --  overlapping_submaps_trimmer_2d = {
  --    fresh_submaps_count = 1,
  --    min_covered_area = 2,
  --    min_added_submaps_count = 5,
  --  },
}

 

六、调参总结

待写$......$

 

七、结语

暂时还没有对参数做很详细的介绍，在后续分析源码的过程中，会对该篇博客增加更多详细的介绍。另外，看了这些参数之后，一脸懵逼，完全不知道怎么回事，这是正常的，因为还没有分析源码，等分析源码之后，大家就明白具体是怎么回事了。