When I used slam_karto to build a map, I found that some places in the map I built without obstacles were regarded as obstacles. The following is the launch file. How should I debug it?

<launch>
  <node pkg="slam_karto" type="slam_karto" name="map_node" output="screen">
    <!--remap from="scan" to="scan"/-->
    <param name="odom_frame" value="odom"/>
    <param name="map_update_interval" value="1"/>
    <param name="resolution" value="0.1"/>
    <param name="delta" value="0.15"/>
    <param name="do_loop_closing" value="true"/>
    <param name="loop_matching_minimum_chain_size" value="10"/>
    <param name="loop_matching_maximum_variance_coarse" value="math::Square(0.4)"/>
    <param name="loop_matching_minimum_response_coarse" value="1"/>
    <param name="loop_matching_minimum_response_fine" value="0.8"/>
    <param name="transform_publish_period" value="0.0"/>
  </node>
</launch>