Packages Version: v3.2.1

Introduction

This package can send control command to real robot from ROS. You can do low-level control(namely control all joints on robot) and high-level control(namely control the walking direction and speed of robot).

This version is suitable for unitree_legged_sdk v3.2 and v3.1, namely A1 and Aliengo robot. Currently, all the A1 and Aliengo use v3.2. If your Aliengo is really old, then it may use v3.1. As for Go1, please use the v3.4 release version of this package and unitree_legged_sdk v3.4.

Packages:

Basic message function: unitree_legged_msgs

The interface between ROS and real robot: unitree_legged_real

Dependencies

• unitree_legged_sdk: If your robot is suitable for unitree_legged_sdk, then you do not need aliengo_sdk.
• aliengo_sdk: If your robot is suitable for aliengo_sdk, then you do not need unitree_legged_sdk.

Configuration

Make sure the following exist in your ~/.bashrc file or export them in terminal. melodic, gazebo-8, ~/catkin_ws, amd64 and the paths to unitree_legged_sdk should be replaced in your own case. If your use unitree_legged_sdk, then you need to set UNITREE_SDK_VERSION=3_2 and the path UNITREE_LEGGED_SDK_PATH. Otherwise, if you use aliengo_sdk, you need to set UNITREE_SDK_VERSION=3_1 and the path ALIENGO_SDK_PATH.

source /opt/ros/melodic/setup.bash
source /usr/share/gazebo-8/setup.sh
source ~/catkin_ws/devel/setup.bash
export ROS_PACKAGE_PATH=~/catkin_ws:${ROS_PACKAGE_PATH}
export GAZEBO_PLUGIN_PATH=~/catkin_ws/devel/lib:${GAZEBO_PLUGIN_PATH}
export LD_LIBRARY_PATH=~/catkin_ws/devel/lib:${LD_LIBRARY_PATH}
# 3_1, 3_2
export UNITREE_SDK_VERSION=3_2
export UNITREE_LEGGED_SDK_PATH=~/unitree_legged_sdk
export ALIENGO_SDK_PATH=~/aliengo_sdk
# amd64, arm32, arm64
export UNITREE_PLATFORM="amd64"

Build

You can use catkin_make to build ROS packages. First copy the package folder to ~/catkin_ws/src, then:

cd ~/catkin_ws
catkin_make

Before compiling unitree_legged_real, please make sure that the unitree_legged_msgs has been compiled.

Setup the net connection

First, please connect the network cable between your PC and robot. Then run ifconfig in a terminal, you will find your port name. For example, enx000ec6612921.

Then, open the ipconfig.sh file under the folder unitree_legged_real, modify the port name to your own. And run the following commands:

sudo chmod +x ipconfig.sh
sudo ./ipconfig.sh

If you run the ifconfig again, you will find that port has inet and netmask now. In order to set your port automatically, you can modify interfaces:

sudo gedit /etc/network/interfaces

And add the following 4 lines at the end:

auto enx000ec6612921
iface enx000ec6612921 inet static
address 192.168.123.162
netmask 255.255.255.0

Where the port name have to be changed to your own.

Run the package

You can control your real robot(only A1 and Aliengo) from ROS by this package.

First you have to run the real_launch under root account:

sudo su
source /home/yourUserName/catkin_ws/devel/setup.bash
roslaunch unitree_legged_real real.launch rname:=a1 ctrl_level:=highlevel firmwork:=3_2

Please watchout that the /home/yourUserName means the home directory of yourself. These commands will launch a LCM server. The rname means robot name, which can be a1 or aliengo(case does not matter), and the default value is a1. And the ctrl_level means the control level, which can be lowlevel or highlevel(case does not matter), and the default value is highlevel. Under the low level, you can control the joints directly. And under the high level, you can control the robot to move or change its pose. The firmwork means the firmwork version of the robot. The default value is 3_2 Now all the A1's firmwork version is 3_2.

In order to send message to robot, you need to run the controller in another terminal(also under root account):

rosrun unitree_legged_real position_lcm

We offered some examples. When you run the low level controller, please make sure the robot is hanging up. The low level contains:

position_lcm
velocity_lcm
torque_lcm

The velocity_lcm and torque_lcm have to run under root account too. Please use the same method as runing real_launch.

And when you run the high level controller, please make sure the robot is standing on the ground. The high level only has walk_lcm.