Go2 Controller

Features

1. Forward Kinematics (FK)
2. Inverse Kinematics (IK)
3. Low-level control command
4. PhysicalSim: Open the viewer from a class
5. read_Jointstate: read topic "rt/lowstate"
6. read_Taskspace: read topic "rt/sportmodestate"

Identify the Go2.XML

The legs and joints are organized as follows:

• Front Left Leg (FL)

  • Joints: FL_hip_joint, FL_thigh_joint, FL_calf_joint
  • End-effector: FL_foot

• Front Right Leg (FR)

  • Joints: FR_hip_joint, FR_thigh_joint, FR_calf_joint
  • End-effector: FR_foot

• Rear Left Leg (RL)

  • Joints: RL_hip_joint, RL_thigh_joint, RL_calf_joint
  • End-effector: RL_foot

• Rear Right Leg (RR)

  • Joints: RR_hip_joint, RR_thigh_joint, RR_calf_joint
  • End-effector: RR_foot

unitree_sdk2py_bridge API

In unitree_sdk2py_bridge.py, the following topics are published by Mujoco:

TOPIC_LOWSTATE = "rt/lowstate"
TOPIC_HIGHSTATE = "rt/sportmodestate"

These topics provide joint states (q, dq, tau) which are not equal to qpos because the order is changed, as well as IMU data and power data. The high state "sportmodestate" provides IMU sensor data positions (x, y, z, dx, dy, dz).

** when give the command to the api, it need to switch the order.

Xpos == Link_index

<<------------- Link ------------->> link_index: 0 , name: world link_index: 1 , name: base_link link_index: 2 , name: FL_hip link_index: 3 , name: FL_thigh link_index: 4 , name: FL_calf link_index: 5 , name: FL_foot link_index: 6 , name: FR_hip link_index: 7 , name: FR_thigh link_index: 8 , name: FR_calf link_index: 9 , name: FR_foot link_index: 10 , name: RL_hip link_index: 11 , name: RL_thigh link_index: 12 , name: RL_calf link_index: 13 , name: RL_foot link_index: 14 , name: RR_hip link_index: 15 , name: RR_thigh link_index: 16 , name: RR_calf link_index: 17 , name: RR_foot

Command index == sensor data index

sensor_index: 0 , name: FR_hip_pos , dim: 1 sensor_index: 1 , name: FR_thigh_pos , dim: 1 sensor_index: 2 , name: FR_calf_pos , dim: 1 sensor_index: 3 , name: FL_hip_pos , dim: 1 sensor_index: 4 , name: FL_thigh_pos , dim: 1 sensor_index: 5 , name: FL_calf_pos , dim: 1 sensor_index: 6 , name: RR_hip_pos , dim: 1 sensor_index: 7 , name: RR_thigh_pos , dim: 1 sensor_index: 8 , name: RR_calf_pos , dim: 1 sensor_index: 9 , name: RL_hip_pos , dim: 1 sensor_index: 10 , name: RL_thigh_pos , dim: 1 sensor_index: 11 , name: RL_calf_pos , dim: 1