# Unitree Go2 Description
This repository contains the urdf model of go2.

![go2](../../../.images/go2.png)

Tested environment:
* Ubuntu 24.04
  * ROS2 Jazzy
* Ubuntu 22.04
  * ROS2 Humble

## Build
```bash
cd ~/ros2_ws
colcon build --packages-up-to go2_description --symlink-install
```

## Visualize the robot
To visualize and check the configuration of the robot in rviz, simply launch:
```bash
source ~/ros2_ws/install/setup.bash
ros2 launch go2_description visualize.launch.py
```

## Launch ROS2 Control
### Mujoco Simulator
* Unitree Guide Controller
  ```bash
  source ~/ros2_ws/install/setup.bash
  ros2 launch go2_description unitree_guide.launch.py
  ```
* OCS2 Quadruped Controller
  ```bash
  source ~/ros2_ws/install/setup.bash
  ros2 launch go2_description ocs2_control.launch.py
  ```
  
### Gazebo Simulator
* Unitree Guide Controller
  ```bash
  source ~/ros2_ws/install/setup.bash
  ros2 launch go2_description gazebo_unitree_guide.launch.py
  ```

## When used for isaac gym or other similiar engine 

Collision parameters in urdf can be amended to better train the robot:

Open "go2_description.urdf" in "./go2_description/urdf",
and amend the ` box size="0.213 0.0245 0.034" ` in links of "FL_thigh", "FR_thigh", "RL_thigh", "RR_thigh".

For example, change previous values to ` box size="0.11 0.0245 0.034" ` means the length of the thigh is shortened from 0.213 to 0.11, which can avoid unnecessary collision between the thigh link and the calf link. 

The collision model before and after the above amendment are shown as "Normal_collision_model.png" and "Amended_collision_model.png" respectively.