EAI激光雷达X4使用hector_slam建图（四）

之前有ROS发烧友跟我说，按照我的博文去做，hector实现建图的效果很凌乱，那是因为hector不适合复杂的环境，如果环境特别凌乱的话，建图的效果不是很好，所以我推荐使用gmapping建图的效果会更好，

以下是我用hector在室内和室外走廊建图的效果图，(绿线的是建图过程中机器人所行走过的路线)，里程计没有做好的ROS发烧友们可以尝试一下用lase_scan_matcher这个package

可以看出，hector对环境特征不是很明显的地方，如长廊之类的建图效果会比较好，然而在比较凌乱的室内环境中，建出来的图就显得比较杂乱。

附上launch代码：

mapping_default.launch代码如下:

<?xml version="1.0"?>

<launch>
  <arg name="pub_map_scanmatch_transform" default="true"/>
  <arg name="tf_map_scanmatch_transform_frame_name" default="scanmatcher_frame"/>
  <arg name="base_frame" default="base_link"/>
  <arg name="odom_frame" default="odom"/>
  <!--arg name="odom_frame" default="pose2D"/-->
  <!--arg name="odom_frame" default="base_link"/-->
  <arg name="pub_map_odom_transform" default="true"/>
  <arg name="scan_subscriber_queue_size" default="5"/>
  <arg name="scan_topic" default="scan"/>
  <arg name="map_size" default="2048"/>
  
  <node pkg="hector_mapping" type="hector_mapping" name="hector_mapping" output="screen">
    
    <!-- Frame names -->
    <param name="map_frame" value="map" />
    <param name="base_frame" value="$(arg base_frame)" />
    <param name="odom_frame" value="$(arg odom_frame)" />
    
    <!-- Tf use -->
    <param name="use_tf_scan_transformation" value="true"/>
    <param name="use_tf_pose_start_estimate" value="false"/>
    <param name="pub_map_odom_transform" value="$(arg pub_map_odom_transform)"/>
    
    <!-- Map size / start point -->
    <param name="map_resolution" value="0.050"/>
    <param name="map_size" value="$(arg map_size)"/>
    <param name="map_start_x" value="0.5"/>
    <param name="map_start_y" value="0.5" />
    <param name="map_multi_res_levels" value="2" />
    
    <!-- Map update parameters -->
    <param name="update_factor_free" value="0.4"/>
    <param name="update_factor_occupied" value="0.7" />    
    <param name="map_update_distance_thresh" value="0.2"/>
    <param name="map_update_angle_thresh" value="0.9" />
    <param name="laser_z_min_value" value = "-1.0" />
    <param name="laser_z_max_value" value = "1.0" />
    
    <!-- Advertising config --> 
    <param name="advertise_map_service" value="true"/>
    
    <param name="scan_subscriber_queue_size" value="$(arg scan_subscriber_queue_size)"/>
    <param name="scan_topic" value="$(arg scan_topic)"/>
    
    <!-- Debug parameters -->
    <!--
      <param name="output_timing" value="false"/>
      <param name="pub_drawings" value="true"/>
      <param name="pub_debug_output" value="true"/>
    -->
    <param name="tf_map_scanmatch_transform_frame_name" value="$(arg tf_map_scanmatch_transform_frame_name)" />
  </node>


  <!--node pkg ="tf" type="static_transform_publisher" name="map_nav_broadcaster" args="0 0 0 0 0 0 map nav 20"/-->
  <!--node pkg ="tf" type="static_transform_publisher" name ="map_scanmatcher_broadcaster" args ="0 0 0 0 0 0 map base_link 25"/-->
  

</launch>

  lase_scan_matcher这个package下的demo.launch代码如下：

<!--
Example launch file: launches the scan matcher with pre-recorded data
-->


<launch>


  <arg name="publish_covariance" default="true"/>
  #### set up data playback from bag #############################




  <!--group if="$(arg use_rviz)">
  <node pkg="rviz" type="rviz" name="rviz" args="-d $(find laser_scan_matcher)/demo/demo.rviz"/>
  </group-->






  #### publish an example base_link -> laser transform ###########


  ##### start the laser scan_matcher ##############################
   
  <group if="$(arg publish_covariance)">
    <param name="laser_scan_matcher_node/do_compute_covariance" value="1"/>
    <param name="laser_scan_matcher_node/publish_pose_with_covariance" value="true"/>
    <param name="laser_scan_matcher_node/publish_pose_with_covariance_stamped" value="true"/>
  </group>
  
  <node pkg="laser_scan_matcher" type="laser_scan_matcher_node" name="laser_scan_matcher_node" output="screen">


    <param name="cloud_range_max" value="10"/>


    <param name="use_imu" value="true"/>
    <param name="use_odom" value="false"/>


    <param name="pose2D" value="odom"/>


    <!--param name="fixed_frame" value = "map"/-->
    <param name="use_cloud_input" value="true"/>
    <param name="max_iterations" type="double" value="20"/>


    <param name="sigma" value="0.012"/>


  </node>


  <!--node pkg="polar_scan_matcher" type="psm_node" name="psm_node" 
    output="screen">
    
    <param name="max_error" value="0.20"/>
    <param name="search_window" value="100"/>
 
    <param name="odometry_type" value="imu"/> 
    
    <param name="world_frame" value="map"/>
 
  </node-->
  
</launch>