Pointers towards using robot_localization for VO + Wheel odometry

edit

Hey , i am trying to setup a EKF fusion for combining odometry coming from two topics

1. Visual Odometry (X , Y and yaw)
2. Wheel Encoders ( X , Y and yaw)

The main source of Odometry is coming from wheel encoders , the visual odometry is there much like a correction mechanism like while using IMUs. Having said that , my VO node publishes Twist values , is it better to fuse the wheel odometry using Twist values using robot_localization ?

I am getting the following error when i launch rviz to view the odometry

Assertion `!pos.isNaN() && "Invalid vector supplied as parameter"' failed.

I am confused with how the TF should be setup . The TF of wheel encoder odometry is as follows

 frame_id: "odom"
 child_frame_id: "base_link"

TF of the visual Odometry is as follows

frame_id: "raspicam"
child_frame_id: ''

AFTER LAUNCHING THE EKF NODE

BEFORE LAUNCHING THE EKF NODE

* MY EKF LAUNCH FILE LOOKS LIKE THIS *

<node pkg="robot_localization" type="ekf_localization_node" name="ekf_localization_custom" clear_params="true"> <!-- renamed to ekf_localization_custom to prevent name conflicts -->

  <param name="frequency" value="30"/> <!-- this value should be fine -->

  <param name="sensor_timeout" value="0.1"/> <!-- this value should be fine -->

  <param name="two_d_mode" value="false"/> <!-- could make this true to stick to XY plane.. -->

  <!-- based these values off of the ROScon presentation -->
  <param name="map_frame" value="map"/>
  <param name="odom_frame" value="odom"/>
  <param name="base_link_frame" value="base_link"/>
  <param name="world_frame" value="odom"/>

  <param name="odom0" value="/optical_flow"/>
  <param name="odom1" value="/ubiquity_velocity_controller/odom"/>

  <!-- settings for using Twist -->
  <rosparam param="odom0_config">[false, false,  false,
                                  false, false, false,
                                  true, true, false,
                                  false, false, true,
                                  false, false, false]</rosparam>


 <rosparam param="odom1_config">[false, false, false,  
                              false, false, true, 
                              true, true, false,   
                              false, false, true,
                              false, false, false]</rosparam>

  <param name="odom0_differential" value="false"/>
  <param name="odom1_differential" value="false"/>
  <param name="publish_null_when_lost" value="false"/>
  <param name="odom0_relative" value="false"/>
  <param name="odom1_relative" value="false"/>

  <param name="odom0_queue_size" value="10"/>
<remap from="/odometry/filtered" to="/odometry/visual" />
</node>

[EDIT #1 adding sensor data samples ]

Wheel Odometry

 header: 
  seq: 3786
  stamp: 
    secs: 1529497452
    nsecs: 845127379
  frame_id: "odom"
child_frame_id: "base_link"
pose: 
  pose: 
    position: 
      x: 0.50
      y: 0.20
      z: 0.0
    orientation: 
      x: 0.0
      y: 0.0
      z: 0.01
      w: 1.0
  covariance: [0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2]
twist: 
  twist: 
    linear: 
      x: 0.8334
      y: 0.0
      z: 0.0
    angular: 
      x: 0.0
      y: 0.0
      z: 0.1233
  covariance: [0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2, 0.0, 0.0, 0.0, 0.0, 0.0, 0 ...