OCS2 Quadruped Controller

This is a ros2-control controller based on legged_control and ocs2_ros2.

Tested environment:

• Ubuntu 24.04
  • ROS2 Jazzy
• Ubuntu 22.04
  • ROS2 Humble
• [2025-01-16] Add support for ground truth estimator.
• [2025-03-15] OCS2 Controller now can switch between passive and MPC mode.

1. Interfaces

Required hardware interfaces:

• command:
  • joint position
  • joint velocity
  • joint effort
  • KP
  • KD
• state:
  • joint effort
  • joint position
  • joint velocity
  • imu sensor
    • linear acceleration
    • angular velocity
    • orientation
  • feet force sensor

2. Build

2.1 Build Dependencies

Before install OCS2 ROS2, please follow the guide to install Pinocchio. Don’t use the pinocchio install by rosdep!

After installed Pinocchio, follow below step to clone ocs2 ros2 library to src folder.

cd ~/ros2_ws/src
git clone https://github.com/legubiao/ocs2_ros2

cd ocs2_ros2
git submodule update --init --recursive

cd ..
rosdep install --from-paths src --ignore-src -r -y

2.2 Build OCS2 Quadruped Controller

cd ~/ros2_ws
colcon build --packages-up-to ocs2_quadruped_controller  --symlink-install

3. Launch

supported robot description:

• Unitree
  • go2_description
  • go1_description
  • a1_description
  • aliengo_description
  • b2_description
• Xiaomi
  • cyberdog_description
• DeepRobotics
  • lite3_description
  • x30_description
• Anybotics
  • anymal_c_description

3.1 About OCS2 Shared Library

OCS2 Quadruped controller depends on the OCS2 library, it required c++ automatic differentiation shared library. When first launch the controller, it will compile the OCS2 model and generate the shared library.

You may see something similar to:

[gazebo-5] [CppAdInterface] Compiling Shared Library: /home/biao/ocs2_cpp_ad/b2/RR_foot_position/cppad_generated/RR_foot_position_libcppadcg_tmp-27918274.so
[gazebo-5] [CppAdInterface] Renaming /home/biao/ocs2_cpp_ad/b2/RR_foot_position/cppad_generated/RR_foot_position_libcppadcg_tmp-27918274.so to /home/biao/ocs2_cpp_ad/b2/RR_foot_position/cppad_generated/RR_foot_position_lib.so
[gazebo-5] [CppAdInterface] Compiling Shared Library: /home/biao/ocs2_cpp_ad/b2/RR_foot_velocity/cppad_generated/RR_foot_velocity_libcppadcg_tmp-94918274.so
[gazebo-5] [CppAdInterface] Renaming /home/biao/ocs2_cpp_ad/b2/RR_foot_velocity/cppad_generated/RR_foot_velocity_libcppadcg_tmp-94918274.so to /home/biao/ocs2_cpp_ad/b2/RR_foot_velocity/cppad_generated/RR_foot_velocity_lib.so
[gazebo-5] [CppAdInterface] Compiling Shared Library: /home/biao/ocs2_cpp_ad/b2/RR_foot_orientation/cppad_generated/RR_foot_orientation_libcppadcg_tmp-83618274.so
[gazebo-5] [CppAdInterface] Renaming /home/biao/ocs2_cpp_ad/b2/RR_foot_orientation/cppad_generated/RR_foot_orientation_libcppadcg_tmp-83618274.so to /home/biao/ocs2_cpp_ad/b2/RR_foot_orientation/cppad_generated/RR_foot_orientation_lib.so

The compilation process may take a few minutes. After the compilation, restart the controller and the robot should stand up.

To config the path for the cppAD shared library, you can modify the modelFolderCppAd item in task.info file, which located at the config/ocs2 folder under robot description package. If the path is not start with /, it will be considered as relative path to the Linux Home folder.

3.2 Usage

Keyboard State Switch

• Keyboard 1 : Passive Mode
• Keyboard 2 : OCS2 MPC Mode
  • Keyboard 2: stance
  • Keyboard 3: trot
  • Keyboard 4: standing_trot
  • Keyboard 5: flying_trot

3.3 Launch Controller

Mujoco Simulation

Warm Reminder: You need to launch Unitree Mujoco C++ Simulation before launch the controller.

source ~/ros2_ws/install/setup.bash
ros2 launch ocs2_quadruped_controller mujoco.launch.py pkg_description:=go2_description

Gazebo Launch

source ~/ros2_ws/install/setup.bash
ros2 launch ocs2_quadruped_controller gazebo.launch.py pkg_description:=go2_description