Pose estimation error with ar_pose

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I am using ar_pose package to estimate the pose of aruco marker.

The camera I used is the gazebo camera. The description of the camera is following in urdf file:

 <gazebo reference="robotiq_wrist_camera_link">
<sensor type="camera" name="wrist_camera">
  <update_rate>30.0</update_rate>
  <camera name="camera on wrist">
    <horizontal_fov>0.8727</horizontal_fov>
    <image>
      <width>640</width>
      <height>480</height>
      <format>BGR8</format>
    </image>
    <clip>
      <near>0.02</near>
      <far>50</far>
    </clip>
    <noise>
      <type>gaussian</type>
      <mean>0.0</mean>
      <stddev>0.007</stddev>
    </noise>
  </camera>
  <plugin name="camera_controller" filename="libgazebo_ros_camera.so">
    <alwaysOn>true</alwaysOn>
    <updateRate>0.0</updateRate>
    <cameraName>camera</cameraName>
    <imageTopicName>image_raw</imageTopicName>
    <cameraInfoTopicName>camera_info</cameraInfoTopicName>
    <frameName>camera_link_optical</frameName>
    <hackBaseline>0.07</hackBaseline>
    <distortionK1>0.0</distortionK1>
    <distortionK2>0.0</distortionK2>
    <distortionK3>0.0</distortionK3>
    <distortionT1>0.0</distortionT1>
    <distortionT2>0.0</distortionT2>
  </plugin>
</sensor></gazebo>

In launch file, I ran the ar_pose node like this:

<node name="ar_pose" pkg="ar_pose" type="ar_single" respawn="false" output="screen">
<param name="marker_pattern" type="string" value="data/4x4/4x4_24.patt"/>
<param name="marker_width" type="double" value="25"/>
<param name="marker_center_x" type="double" value="0.0"/>
<param name="marker_center_y" type="double" value="0.0"/>
<param name="threshold" type="int" value="100"/>
<param name="use_history" type="bool" value="true"/></node>

The estimation result shows in the picture.

It seems that the detected pose is not aligned to the marker pose. Someone knows why and thanks for the attention!