Uncontrallable urdf of 2 link arm in Gazebo

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 > After 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 transmission_interface/SimpleTransmissionhardware_interface/EffortJointInterfacehardware_interface/EffortJointInterface1