diff --git a/.images/gazebo_classic.png b/.images/gazebo_classic.png
new file mode 100644
index 0000000..097e52a
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diff --git a/README.md b/README.md
index f0e79d3..769f4b1 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,14 @@
 # Quadruped ROS2 Control
 
-This repository contains the ros2-control based controllers for the quadruped robot. 
-* [Controllers](controllers): contains the ros2-control controllers 
+This repository contains the ros2-control based controllers for the quadruped robot.
+
+* [Controllers](controllers): contains the ros2-control controllers
 * [Commands](commands): contains command node used to send command to the controller
 * [Descriptions](descriptions): contains the urdf model of the robot
 * [Hardwares](hardwares): contains the ros2-control hardware interface for the robot
 
 Todo List:
+
 - [x] [Mujoco Simulation](hardwares/hardware_unitree_mujoco)
 - [x] [Unitree Guide Controller](controllers/unitree_guide_controller)
 - [x] [Gazebo Simulation](descriptions/quadruped_gazebo)
@@ -23,8 +25,8 @@ Video for Unitree Guide Controller:
 Video for OCS2 Quadruped Controller:
 [![](http://i0.hdslb.com/bfs/archive/e758ce019587032449a153cf897a543443b64bba.jpg)](https://www.bilibili.com/video/BV1UcxieuEmH/)
 
-
 ## 1. Quick Start
+
 * rosdep
     ```bash
     cd ~/ros2_ws
@@ -36,9 +38,13 @@ Video for OCS2 Quadruped Controller:
     ```
 
 ### 1.1 Mujoco Simulator
-Please use this [Mujoco Simulation](https://github.com/legubiao/unitree_mujoco) for more robot models and contact sensor.
 
-> **Warning:** CycloneDDS ROS2 RMW may conflict with unitree_sdk2. If you cannot launch unitree mujoco simulation without `sudo`, then you cannot used `unitree_mujoco_hardware`. You can switch to gazebo, or try to solve the conflict by uninstall CycloneDDS ROS2 RMW.
+Please use this [Mujoco Simulation](https://github.com/legubiao/unitree_mujoco) for more robot models and contact
+sensor.
+
+> **Warning:** CycloneDDS ROS2 RMW may conflict with unitree_sdk2. If you cannot launch unitree mujoco simulation
+> without `sudo`, then you cannot used `unitree_mujoco_hardware`. You can switch to gazebo, or try to solve the conflict
+> by uninstall CycloneDDS ROS2 RMW.
 
 * Launch the unitree mujoco go2 simulation
 * Launch the ros2-control
@@ -53,22 +59,10 @@ Please use this [Mujoco Simulation](https://github.com/legubiao/unitree_mujoco)
     ```
 
 ### 1.2 Gazebo Classic Simulator (ROS2 Humble)
-* Compile Leg PD Controller
-    ```bash
-    colcon build --packages-up-to leg_pd_controller
-    ```
-* Launch the ros2-control
-    ```bash
-    source ~/ros2_ws/install/setup.bash
-    ros2 launch unitree_guide_controller gazebo.launch.py
-    ```
-* Run the keyboard control node
-    ```bash
-    source ~/ros2_ws/install/setup.bash
-    ros2 run keyboard_input keyboard_input
-    ```
-
-### 1.3 Gazebo Harmonic Simulator (ROS2 Jazzy)
+* Install Gazebo Classic
+  ```bash
+  sudo apt-get install ros-humble-gazebo-ros ros-humble-gazebo-ros2-control
+  ```
 * Compile Leg PD Controller
     ```bash
     colcon build --packages-up-to leg_pd_controller
@@ -84,16 +78,51 @@ Please use this [Mujoco Simulation](https://github.com/legubiao/unitree_mujoco)
     ros2 run keyboard_input keyboard_input
     ```
 
-For more details, please refer to the [unitree guide controller](controllers/unitree_guide_controller/) and [go2 description](descriptions/unitree/go2_description/).
+![gazebo classic](.images/gazebo_classic.png)
+
+
+### 1.3 Gazebo Harmonic Simulator (ROS2 Jazzy)
+
+* Install Gazebo
+  ```bash
+  sudo apt-get install ros-jazzy-ros-gz ros-jazzy-gz-ros2-control
+  ```
+
+* Compile Leg PD Controller
+    ```bash
+    colcon build --packages-up-to leg_pd_controller
+    ```
+* Launch the ros2-control
+    ```bash
+    source ~/ros2_ws/install/setup.bash
+    ros2 launch unitree_guide_controller gazebo.launch.py
+    ```
+* Run the keyboard control node
+    ```bash
+    source ~/ros2_ws/install/setup.bash
+    ros2 run keyboard_input keyboard_input
+    ```
+
+For more details, please refer to the [unitree guide controller](controllers/unitree_guide_controller/)
+and [go2 description](descriptions/unitree/go2_description/).
 
 ## Reference
 
 ### Conference Paper
-[1] Liao, Qiayuan, et al. "Walking in narrow spaces: Safety-critical locomotion control for quadrupedal robots with duality-based optimization." In *2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)*, pp. 2723-2730. IEEE, 2023.
+
+[1] Liao, Qiayuan, et al. "Walking in narrow spaces: Safety-critical locomotion control for quadrupedal robots with
+duality-based optimization." In *2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)*, pp.
+2723-2730. IEEE, 2023.
 
 ### Miscellaneous
-[1] Unitree Robotics. *unitree\_guide: An open source project for controlling the quadruped robot of Unitree Robotics, and it is also the software project accompanying 《四足机器人控制算法--建模、控制与实践》 published by Unitree Robotics*. [Online]. Available: [https://github.com/unitreerobotics/unitree_guide](https://github.com/unitreerobotics/unitree_guide)
 
-[2] Qiayuan Liao. *legged\_control: An open-source NMPC, WBC, state estimation, and sim2real framework for legged robots*. [Online]. Available: [https://github.com/qiayuanl/legged_control](https://github.com/qiayuanl/legged_control)
+[1] Unitree Robotics. *unitree\_guide: An open source project for controlling the quadruped robot of Unitree Robotics,
+and it is also the software project accompanying 《四足机器人控制算法--建模、控制与实践》 published by Unitree
+Robotics*. [Online].
+Available: [https://github.com/unitreerobotics/unitree_guide](https://github.com/unitreerobotics/unitree_guide)
 
-[3] Ziqi Fan. *rl\_sar: Simulation Verification and Physical Deployment of Robot Reinforcement Learning Algorithm.* 2024. Available: [https://github.com/fan-ziqi/rl_sar](https://github.com/fan-ziqi/rl_sar) 
\ No newline at end of file
+[2] Qiayuan Liao. *legged\_control: An open-source NMPC, WBC, state estimation, and sim2real framework for legged
+robots*. [Online]. Available: [https://github.com/qiayuanl/legged_control](https://github.com/qiayuanl/legged_control)
+
+[3] Ziqi Fan. *rl\_sar: Simulation Verification and Physical Deployment of Robot Reinforcement Learning Algorithm.*
+2024. Available: [https://github.com/fan-ziqi/rl_sar](https://github.com/fan-ziqi/rl_sar) 
\ No newline at end of file
diff --git a/controllers/leg_pd_controller/CMakeLists.txt b/controllers/leg_pd_controller/CMakeLists.txt
index 0c07275..b06f7f5 100644
--- a/controllers/leg_pd_controller/CMakeLists.txt
+++ b/controllers/leg_pd_controller/CMakeLists.txt
@@ -22,11 +22,11 @@ foreach (Dependency IN ITEMS ${CONTROLLER_INCLUDE_DEPENDS})
 endforeach ()
 
 # check ros2 control version
-find_package(controller_manager 3.0.0)
+find_package(controller_manager REQUIRED)
 # Handle the case where the required version is not found
-if(NOT controller_manager_FOUND)
+if(controller_manager_VERSION VERSION_LESS "3.0.0")
     add_definitions(-DROS2_CONTROL_VERSION_LT_3)
-    message(FATAL_ERROR "ros2_control version below 3.0.0. "
+    message(STATUS "ros2_control version below 3.0.0. "
             "Change the implementation to support ros2_control version 2.")
 endif()