Uncontrallable urdf of 2 link arm in Gazebo

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Hello, I'd like to make a 2 link arm model by using urdf to simulate it in Gazebo. I made urdf of 2 link arm and launch file that execute simulation in Gazebo. But my model is uncontrollable like the attached pictures. Please let me know where I should improve the urdf model.

My ideal state of 2 link arm is the following. When I change the ensor of inertia as the following , it is better than the above model.

Before

 <inertia
  ixx="${mass / 12.0 * (width*width + width*width)}" ixy="0.0" ixz="0.0"
  iyy="${mass / 12.0 * (height1*height1 + width*width)}" iyz="0.0"
  izz="${mass / 12.0 * (height1*height1 + width*width)}"/>
</inertial>

After

 <inertia
  ixx="${mass / 12.0 * (width*width + height1*height1)}" ixy="0.0" ixz="0.0"
  iyy="${mass / 12.0 * (height1*height1 + width*width)}" iyz="0.0"
  izz="${mass / 12.0 * (width*width + width*width)}"/>
</inertial>

But it is still uncontrollable. I also think the former ensor of inertia is proper.

I show the tree structure of my package.

├── CMakeLists.txt
├── config
│   └── controller.yaml
├── include
├── launch
│   ├── control.launch
│   ├── display.launch
│   └── gazebo.launch
├── materials.xacro
├── one_link_arm2.gazebo
├── one_link_arm2.urdf
├── package.xml
└── src

one_link_arm2.urdf is the following

   <?xml version="1.0"?>
   <!-- Revolute-Revolute Manipulator -->
   <robot name="one_link_arm2" xmlns:xacro="http://www.ros.org/wiki/xacro">

   <!-- Constants for robot dimensions -->
   <xacro:property name="PI" value="3.1415926535897931"/>
   <xacro:property name="mass" value="1" /> <!-- arbitrary value for mass -->
   <xacro:property name="width" value="0.1" /> <!-- Square dimensions (widthxwidth) of beams -->
  <xacro:property name="height1" value="2" /> <!-- Link 1 -->
  <xacro:property name="height2" value="1" /> <!-- Link 2 -->
 <xacro:property name="axel_offset" value="0.05" /> <!-- Space btw top of beam and the each joint -->

  <!-- Import all Gazebo-customization elements, including Gazebo colors -->
  <xacro:include filename="$(find one_link_arm2)/one_link_arm2.gazebo" />
  <!-- Import Rviz colors -->
  <xacro:include filename="$(find one_link_arm2)/materials.xacro" />

  <!-- Used for fixing robot to Gazebo 'base_link' -->
  <link name="world"/>

  <joint name="fixed" type="fixed">
    <parent link="world"/>
    <child link="link1"/>
  </joint>

  <!-- Base Link -->
  <link name="link1">
    <collision>
      <origin xyz="${height1/2} 0 0" rpy="0 0 0"/>
      <geometry>
    <box size="${height1} ${width} ${width}"/>
      </geometry>
    </collision>
   <visual>
      <origin xyz="${height1/2} 0 0" rpy="0 0 0"/>
      <geometry>
        <box size="${height1} ${width} ${width}"/>
      </geometry>
      <material name="orange"/>
    </visual>
    <inertial>
      <origin xyz="${height1/2} 0 0" rpy="0 0 0"/>
      <mass value="${2*mass}"/>
      <inertia
      ixx="${mass / 12.0 * (width*width + height1*height1)}" ixy="0.0" ixz="0.0"
      iyy="${mass / 12.0 * (height1*height1 + width*width)}" iyz="0.0"
      izz="${mass / 12.0 * (width*width + width*width)}"/>
    </inertial>
  </link>

  <joint name="joint1" type="continuous">
    <parent link="link1"/>
    <child link="link2"/>
    <origin xyz="${height1 - axel_offset} 0 ${width}" rpy="0 0 0"/>
    <axis xyz="0 0 1"/>
    <dynamics damping="0.7"/>
  </joint>

 <!-- Middle Link -->
  <link name="link2">
    <collision>
      <origin xyz="${height2/2 - axel_offset} 0 0" rpy="0 0 0"/>
      <geometry>
    <box size="${height2} ${width} ${width}"/>
      </geometry>
    </collision>

   <visual>
      <origin xyz="${height2/2 - axel_offset} 0 0" rpy="0 0 0"/>
      <geometry>

    <box size="${height2 ...