Map drifted immediately while odometry is from robot_localization

edit

Dear all, I have been trying robot_localization on RTAB-Map generated VO and IMU(mpu6050). I moved a cart equipped with ZED+IMU around to form a loop. Though I didn't have a ground truth to verify if fusion improves the trajectory. I found that map drifted immediately in fusion mode. I wonder if it's possible for you to look into my launch file and see what might be wrong? Thank you so much. Here's the EKF part in my launch file

  <!-- Odometry fusion (EKF), refer to demo launch file in robot_localization for more info -->
  <node pkg="robot_localization" type="ekf_localization_node" name="ekf_localization" clear_params="true" output="screen">

      <param name="frequency" value="50"/>
      <param name="sensor_timeout" value="0.1"/>
      <param name="two_d_mode" value="false"/>

      <param name="odom_frame" value="odom"/>
      <param name="base_link_frame" value="$(arg frame_id)"/>
      <param name="world_frame" value="odom"/>

      <param name="transform_time_offset" value="0.0"/>

      <param name="odom0" value="/vo"/>
      <param name="imu0" value="$(arg imu_topic)"/> 




      <param name="debug"           value="true"/>
      <param name="debug_out_file"  value="/home/acid/acid/catkin_ws/src/robot_localization/acid_debug_ekf_localization.txt"/>


      <!-- The order of the values is x, y, z, roll, pitch, yaw, vx, vy, vz, vroll, vpitch, vyaw, ax, ay, az. -->
      <rosparam param="odom0_config">[true, true, true,
                                      false, false, false,
                                      true, true, true,
                                      false, false, false,
                                      false, false, false]</rosparam>

      <rosparam     if="$(arg imu_ignore_acc)" param="imu0_config">[
                                     false, false, false,
                                     true,  true,  true,
                                     false, false, false,
                                     true,  true,  true,
                                     false,  false,  false] </rosparam>
      <rosparam unless="$(arg imu_ignore_acc)" param="imu0_config">[
                                     false, false, false,
                                     true,  true,  true,
                                     false, false, false,
                                     true,  true,  true,
                                     true,  true,  true] </rosparam>  

      <param name="odom0_differential" value="false"/>
      <param name="imu0_differential" value="true"/>

      <param name="odom0_relative" value="true"/>
      <param name="imu0_relative" value="false"/>

      <param name="imu0_remove_gravitational_acceleration" value="$(arg imu_remove_gravitational_acceleration)"/>

      <param name="print_diagnostics" value="true"/>

      <!-- ======== ADVANCED PARAMETERS ======== -->
      <param name="odom0_queue_size" value="50"/>
      <param name="imu0_queue_size" value="50"/> 

      <!-- The values are ordered as x, y, z, roll, pitch, yaw, vx, vy, vz,
           vroll, vpitch, vyaw, ax, ay, az. -->
      <rosparam param="process_noise_covariance">[0.005, 0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0.005, 0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0.006, 0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0.003, 0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0.003, 0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0.006, 0,     0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0,    0.0025, 0,     0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0,    0,     0.0025, 0,    0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0,    0,     0,     0.004, 0,    0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0,    0,     0,     0,    0.001, 0,    0,    0,    0,    0,
                                                  0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0.001, 0,    0,    0,    0 ...