ur_gazebo: changed controller configuration does not work

edit

Hello I'm using ros-melodic and I'm having trouble with controlling ur5 manipulator with gazebo

I downloaded ur_gazebo package from https://github.com/ros-industrial/uni...
Planning and execution with the moveit works well.

What I trying to do is to execute position control of each joint from the optimization result.
So, I modified the source code to watch how it works.

What I wanted is to control shoulder_pan_joint by publishing data through rostopic
I changed ur5.launch, and arm_controller_ur5.yaml like below

ur5.launch

<?xml version="1.0"?>
<launch>
  <arg name="limited" default="false"  doc="If true, limits joint range [-PI, PI] on all joints." />
  <arg name="paused" default="false" doc="Starts gazebo in paused mode" />
  <arg name="gui" default="true" doc="Starts gazebo gui" />

  <!-- startup simulated world -->
  <include file="$(find gazebo_ros)/launch/empty_world.launch">
    <arg name="world_name" default="worlds/empty.world"/>
    <arg name="paused" value="$(arg paused)"/>
    <arg name="gui" value="$(arg gui)"/>
  </include>

  <!-- send robot urdf to param server -->
  <include file="$(find ur_description)/launch/ur5_upload.launch">
    <arg name="limited" value="$(arg limited)"/>
  </include>

  <!-- push robot_description to factory and spawn robot in gazebo -->
  <node name="spawn_gazebo_model" pkg="gazebo_ros" type="spawn_model" args="-urdf -param robot_description -model robot -z 0.1" respawn="false" output="screen" />

  <include file="$(find ur_gazebo)/launch/controller_utils.launch"/>

  <!-- start this controller -->
  <rosparam file="$(find ur_gazebo)/controller/arm_controller_ur5.yaml" command="load"/>
  <node name="arm_controller_spawner" pkg="controller_manager" type="controller_manager" args="spawn arm_controller" respawn="false" output="screen"/>

  <!-- load other controllers -->
  <node name="ros_control_controller_manager" pkg="controller_manager" type="controller_manager" respawn="false" output="screen" args="load joint_group_position_controller" />


  <node name="simple_controller" pkg="controller_manager" type="controller_manager" respawn="false" output="screen" args="load prac" />


</launch>

arm_controller.yaml

prac:
  type: position_controllers/JointPositionController
  joint: shoulder_pan_joint
  pid:
    p: 100.0
    d: 10.0


arm_controller:
  type: position_controllers/JointTrajectoryController
  joints:
     - shoulder_pan_joint
     - shoulder_lift_joint
     - elbow_joint
     - wrist_1_joint
     - wrist_2_joint
     - wrist_3_joint
  constraints:
      goal_time: 0.6
      stopped_velocity_tolerance: 0.05
      shoulder_pan_joint: {trajectory: 0.1, goal: 0.1}
      shoulder_lift_joint: {trajectory: 0.1, goal: 0.1}
      elbow_joint: {trajectory: 0.1, goal: 0.1}
      wrist_1_joint: {trajectory: 0.1, goal: 0.1}
      wrist_2_joint: {trajectory: 0.1, goal: 0.1}
      wrist_3_joint: {trajectory: 0.1, goal: 0.1}
  stop_trajectory_duration: 0.5
  state_publish_rate:  25
  action_monitor_rate: 10
joint_group_position_controller:
  type: position_controllers/JointGroupPositionController
  joints:
     - shoulder_pan_joint
     - shoulder_lift_joint
     - elbow_joint
     - wrist_1_joint
     - wrist_2_joint
     - wrist_3_joint

In ur5.launch I added node named simple controller, and in yaml file I added the controller desctription
Then, I run the launch file

roslaunch ur_gazebo ur5.launch

and published desired position by

rostopic pub /prac/command std_msgs/Float64 "data: 0.5"

However, the robot doesn't seem to move.
Can anyone tell me what is wrong?