amcl---Inaccurate positioning

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when I use amcl package, the location is inaccurate.

why?

I guess:

1. the pose from odom-topic has high noise.

2. Parameter setting is problematic.

amcl Parameter:

<launch>
  <arg name="scan_topic"     default="scan"/>
  <arg name="initial_pose_x" default="0.0"/>
  <arg name="initial_pose_y" default="0.0"/>
  <arg name="initial_pose_a" default="0.0"/>

  <node pkg="amcl" type="amcl" name="amcl">

    <param name="min_particles"             value="500"/>
    <param name="max_particles"             value="3000"/>
    <param name="kld_err"                   value="0.02"/>
    <param name="update_min_d"              value="0.20"/>
    <param name="update_min_a"              value="0.20"/>
    <param name="resample_interval"         value="1"/>
    <param name="transform_tolerance"       value="0.5"/>
    <param name="recovery_alpha_slow"       value="0.00"/>
    <param name="recovery_alpha_fast"       value="0.00"/>
    <param name="initial_pose_x"            value="$(arg initial_pose_x)"/>
    <param name="initial_pose_y"            value="$(arg initial_pose_y)"/>
    <param name="initial_pose_a"            value="$(arg initial_pose_a)"/>
    <param name="gui_publish_rate"          value="50.0"/>

    <remap from="scan"                      to="$(arg scan_topic)"/>
    <param name="laser_max_range"           value="14"/>
    <param name="laser_max_beams"           value="30"/>
    <param name="laser_z_hit"               value="0.5"/>
    <param name="laser_z_short"             value="0.05"/>
    <param name="laser_z_max"               value="0.05"/>
    <param name="laser_z_rand"              value="0.5"/>
    <param name="laser_sigma_hit"           value="0.2"/>
    <param name="laser_lambda_short"        value="0.1"/>
    <param name="laser_likelihood_max_dist" value="2.0"/>
    <param name="laser_model_type"          value="likelihood_field"/>

    <param name="odom_model_type"           value="diff"/>
    <param name="odom_alpha1"               value="0.2"/>
    <param name="odom_alpha2"               value="0.2"/>
    <param name="odom_alpha3"               value="0.2"/>
    <param name="odom_alpha4"               value="0.2"/>
    <param name="odom_frame_id"             value="odom"/>
    <param name="base_frame_id"             value="base_footprint"/>

  </node>
</launch>

topic: