unitree_interface

ROS 2 interface for the Unitree G1 humanoid robot (29 DoF). Bridges the Unitree SDK with standard ROS 2 topics and services.

Node

unitree_interface (default name)

Advertised Services

Service	Type	Description
~/change_mode	unitree_interface_msgs/srv/ChangeControlMode	Request a control mode transition. See ControlMode.msg for valid mode IDs.
~/ready_locomotion	std_srvs/srv/Trigger	Runs the locomotion ready sequence (damp, stand up, start). Blocking, retryable on failure.

Published Topics

Topic	Type	Description
~/current_mode	unitree_interface_msgs/msg/ControlMode	Current control mode (latched, reliable).
~/joint_states	sensor_msgs/msg/JointState	Joint state feedback from the robot. Published at the SDK's rt/lowstate rate. Publishes for all 29 joints, using URDF joint names.

Subscribed Topics

Topic	Type	Mode	Description
~/cmd_vel	geometry_msgs/msg/Twist	HighLevelMode	Velocity commands (linear.x, linear.y, angular.z).
~/cmd_arm	sensor_msgs/msg/JointState	HighLevelMode	Arm joint commands via rt/arm_sdk. Uses URDF joint names for upper body joints (arms + waist). Position, velocity, and effort fields are used. Motor kp/kd are set automatically based on gearbox type.
~/cmd_low	sensor_msgs/msg/JointState	LowLevelMode	Direct low-level motor commands for all 29 joints. Requires UNITREE_INTERFACE_ENABLE_LOW_LEVEL_MODE at build time.
/estop	std_msgs/msg/Empty	Any	Emergency stop. Transitions to EmergencyMode (damps all joints). Global topic.
~/tts	std_msgs/msg/String	Any	Text-to-speech via the robot's speaker.

Control Modes

See control_modes.md.

Parameters

Parameter	Type	Default	Description
network_interface	string	"eth0"	Network interface for Unitree SDK communication.
motion_switcher_client_timeout	double	5.0	Timeout (s) for the motion switcher client.
loco_client_timeout	double	10.0	Timeout (s) for the locomotion client.
audio_client_timeout	double	5.0	Timeout (s) for the audio client.
volume	int	100	Speaker volume (0-100).
mode_change_service_name	string	"~/change_mode"	Service name for mode changes.
ready_locomotion_service_name	string	"~/ready_locomotion"	Service name for the locomotion ready sequence.
current_mode_topic	string	"~/current_mode"	Topic for current mode publication.
cmd_vel_topic	string	"~/cmd_vel"	Topic for velocity commands.
cmd_arm_topic	string	"~/cmd_arm"	Topic for arm commands.
joint_states_topic	string	"~/joint_states"	Topic for joint state feedback.
tts_topic	string	"~/tts"	Topic for text-to-speech.
cmd_low_topic	string	"~/cmd_low"	Topic for low-level commands (if enabled).
estop_topic	string	"/estop"	Topic for emergency stop.

Custom Messages (unitree_interface_msgs)

ControlMode.msg

uint8 CONTROL_MODE_MONOSTATE   = 0
uint8 CONTROL_MODE_IDLE        = 1
uint8 CONTROL_MODE_HIGH_LEVEL  = 2
uint8 CONTROL_MODE_EMERGENCY   = 3
uint8 CONTROL_MODE_LOW_LEVEL   = 4

std_msgs/Header header
uint8 current_mode_id
string current_mode_name

ChangeControlMode.srv

uint8 requested_mode
---
bool success
string message

Joints

All joint topics use URDF-style names. See topology.hpp for gearbox assignments.