stan-32 / nmpc4dog

Nonlinear MPC and WBC for legged robot based on OCS2 and ros-controls

legged_control

Introduction

legged_control is an NMPC-WBC legged robot control stack and framework based on OCS2 and ros-control. To the author’s best knowledge, this framework is probably the best-performing open-source legged robot MPC control framework. Thanks to the ros-control interface, you can easily use this framework for your robot.

Installation

Source code

The source code is hosted on GitHub: qiayuanliao/legged_control.

# Clone legged_control
git clone [email protected]:qiayuanliao/legged_control.git

OCS2

OCS2 is a huge monorepo; DO NOT try to compile the whole repo. You only need to compile ocs2_legged_robot_ros and its dependencies following the step below.

1. You are supposed to clone the OCS2, pinocchio, and hpp-fcl as described in the documentation of OCS2.

   # Clone OCS2
   git clone [email protected]:leggedrobotics/ocs2.git
   # Clone pinocchio
   git clone --recurse-submodules https://github.com/leggedrobotics/pinocchio.git
   # Clone hpp-fcl
   git clone --recurse-submodules https://github.com/leggedrobotics/hpp-fcl.git
   # Clone ocs2_robotic_assets
   git clone https://github.com/leggedrobotics/ocs2_robotic_assets.git
   # Install dependencies
   sudo apt install liburdfdom-dev liboctomap-dev libassimp-dev
   

2. Compile the ocs2_legged_robot_ros package with catkin tools instead of catkin_make. It will take you about ten minutes.

   catkin build ocs2_legged_robot_ros
   

   Ensure you can command the ANYmal as shown in the document and below.

Build

Build the source code of legged_control by:

catkin build legged_controllers

Build the simulation (DO NOT run on the onboard computer)

catkin build legged_gazebo

Build the hardware interface real robot. If you use your computer only for simulation, you DO NOT need to compile unitree_hw (TODO: add legged prefix to the package name)

catkin build unitree_hw

Quick Start

1. Set your robot type as an environment variable: ROBOT_TYPE

export ROBOT_TYPE=a1

2. Run the simulation:

roslaunch unitree_description empty_world.launch

Or on the robot hardware:

roslaunch unitree_hw unitree_hw.launch

3. Load the controller:

roslaunch legged_controllers load_controller.launch cheater:=false

4. You can start the controller using rqt_controller_manager

sudo apt install ros-noetic-rqt-controller-manager
rosrun rqt_controller_manager rqt_controller_manager

5. Start the legged_controller or legged_cheater_controller, NOTE that you are not allowed to start the legged_cheater_controller in real hardware!

6. Set the gait in the terminal of load_controller.launch, then use RViz and other tools to control the robot

Statistics

The table below shows the labs successfully deploy this repo in their real A1, feel free to open a PR for update these infos.

Lab	XPeng Robotics	Unitree	Geely Auto	Hybrid Robotics
Spend Time	1 day	-	3 hours	2 hours