robot_pose_ekf does not publish anything

edit

By the way, for a launchfile try this:

<launch>
<node pkg="robot_pose_ekf" type="robot_pose_ekf" name="robot_pose_ekf">
  <param name="output_frame" value="odom_combined"/>
  <param name="base_footprint_frame" value="base_link"/>
  <param name="freq" value="30.0"/>
  <param name="sensor_timeout" value="1.0"/>  
  <param name="odom_used" value="true"/>
  <param name="imu_used" value="true"/>
  <param name="vo_used" value="false"/>
  <remap from="odom" to="encoder/odom" />
 <remap from="imu_data" to="imu/data" />
</node>
</launch>

Try this launchfile the above will not work as encoder/odom uses base_footprint frame:

<launch>
<node pkg="tf" type="static_transform_publisher" name="static_transform" args="0 0 0 0 0 0 0  /base_footprint /base_link  100"/>


<node pkg="robot_pose_ekf" type="robot_pose_ekf" name="robot_pose_ekf">
  <param name="output_frame" value="odom_combined"/>
  <param name="base_footprint_frame" value="base_footprint"/>
  <param name="freq" value="30.0"/>
  <param name="sensor_timeout" value="1.0"/>  
  <param name="odom_used" value="true"/>
  <param name="imu_used" value="true"/>
  <param name="vo_used" value="false"/>
  <remap from="odom" to="encoder/odom" />
 <remap from="imu_data" to="imu/data" />
</node>
</launch>

I try to use the second launch file, and it gives this errors in the terminal window :

link text

and the rosnod info is

$ rosnode info /robot_pose_ekf

Node [/robot_pose_ekf]
Publications: 
 * /robot_pose_ekf/odom_combined [geometry_msgs/PoseWithCovarianceStamped]
 * /rosout [rosgraph_msgs/Log]
 * /tf [tf2_msgs/TFMessage]

Subscriptions: 
 * /encoder/odom [nav_msgs/Odometry]
 * /imu/data [sensor_msgs/Imu]
 * /tf [tf2_msgs/TFMessage]
 * /tf_static [unknown type]

and still there are no outputs foe robot_pose_ekf

Sorry, the static transform publisher had a axis to many, try this:

<launch>
<node pkg="tf" type="static_transform_publisher" name="static_transform" args="0 0 0 0 0 0  /base_footprint /base_link  100"/>


<node pkg="robot_pose_ekf" type="robot_pose_ekf" name="robot_pose_ekf">
  <param name="output_frame" value="odom_combined"/>
  <param name="base_footprint_frame" value="base_footprint"/>
  <param name="freq" value="30.0"/>
  <param name="sensor_timeout" value="1.0"/>  
  <param name="odom_used" value="true"/>
  <param name="imu_used" value="true"/>
  <param name="vo_used" value="false"/>
  <remap from="odom" to="encoder/odom" />
 <remap from="imu_data" to="imu/data" />
</node>
</launch>

[ERROR] [1591037796.233741326]: filter time older than odom message buffer
[ERROR] [1591037796.233884657]: filter time older than odom message buffer
^C[ERROR] [1591037796.330767126]: filter time older than odom message buffer
[ERROR] [1591037796.331129977]: Covariance specified for measurement on topic wheelodom is zero
[ERROR] [1591037796.331370539]: filter time older than odom message buffer
[ERROR] [1591037796.333372238]: filter time older than odom message buffer

Never seen the topic wheelodom before in your posts whats that? The covariances have to fit of course but that has nothing to do with what this question is about. (for testing just make them tiny but non zero) The "filter time..." error is about unsynchronized topics, some data isnt coming in at all or not fast enough, as the timeout is 10 seconds, its likely not coming at all, most likely its the odometry problem causing this error as well. base_odometry_node is publishing odom on encoder/odom topic and the launchfile is remapping this.

The covariances are zero here as well. If those get populated correctly it should all work. So the actual question seems solved. link text Link to a simple start to get into the covariance matrix topic.