Motion Planning with base_local_planner

edit

I'm a bit confused about how to use base_local_planner; I'm following this tutorial . Apologies if questions below seem silly; I'm a newcomer to ROS.

My robot configuration launch file looks like this:

<launch>

 <node pkg="gazebo_plugins" type="hokuyo_node" name="hokuyo_node" output="screen">
    <param name="sensor_param" value="param_value" />
  </node>

 < uncommented for display ; odom is a c++ program I wrote to listen to odometry information -->
 <node pkg="learning_tf" type="odom" name="odom_node" output="screen">
    <param name="odom_param" value="param_value" />
  </node>


  <node pkg="tf" type="tf_echo" name="tf_listener" output="screen" args="/base_link /map">
  </node>

</launch>

My move_base file is the same as erratic_navigation's move_base.launch.

Questions:

1. What are the sensor, odom and transform packages required for the robot configuration file? Are they listeners to the information published by move_base?
2. The only odometry reading I get by looking at rostopic output is from erratic_odom. Is this enough?
3. Is /base_link --> /map the right transformation for tf?
4. What output should I expect after I run both launch files? Shouldn't I be getting a plan through which the robot moves, dumping output?
5. Is hokuyo_node the right sensor?