inspect-robots-unitree-g1

Inspect Robots adapters for a standing Unitree G1 with 7-DoF arms and an Isaac-GR00T PolicyServer. The package registers the g1_arms embodiment and the gr00t policy. Both declare one absolute 16-D joint-position contract.

The locomotion controller remains responsible for balance, legs, and waist. This adapter publishes arm targets to rt/arm_sdk and blends them into the running controller through the weight joint.

Install

Install the package on the G1 adapter machine:

pip install inspect-robots-unitree-g1
pip install "unitree_sdk2py @ git+https://github.com/unitreerobotics/unitree_sdk2_python"
pip install pyzmq msgpack msgpack-numpy opencv-python-headless

A known-good SDK combination is Python 3.12, unitree_sdk2py 1.0.1, and cyclonedds 0.10.2. If the CycloneDDS wheel is unavailable, build CycloneDDS from source, set CYCLONEDDS_HOME, then reinstall the Python package.

The adapter machine must be PC2 or a tethered Linux host with layer-2 access to 192.168.123.0/24. Run a compatible raw-JPEG ZMQ image server for the head D435i on PC2. The builtin reader uses a conflated SUB socket. Inject camera_reader when your image server uses another protocol.

Run Isaac-GR00T on the GPU machine with its PolicyServer and the G1 full-body modality checkpoint. At the pinned API seam, this command loads the checkpoint and listens on port 5555:

export GR00T_CHECKPOINT=/path/to/your/g1-checkpoint
export GR00T_EMBODIMENT_TAG=your_checkpoint_g1_tag
python - <<'PY'
import os

from gr00t.policy.gr00t_policy import Gr00tPolicy
from gr00t.policy.server_client import PolicyServer

policy = Gr00tPolicy(
    embodiment_tag=os.environ["GR00T_EMBODIMENT_TAG"],
    model_path=os.environ["GR00T_CHECKPOINT"],
    device="cuda:0",
)
PolicyServer.start_server(policy, port=5555)
PY

Use the embodiment tag advertised by that checkpoint. This package intentionally does not depend on Isaac-GR00T itself.

Preflight

Preflight checks declarations without connecting to hardware or a server:

inspect-robots-unitree-g1-preflight --dry-run
inspect-robots-unitree-g1-preflight --task cubepick-reach --json --dry-run

The JSON form includes dry_run. A green result proves dimensions, semantics, cameras, state keys, and optional scene realizability. It cannot prove action relativity, hand polarity, network reachability, or safe physical clearance.

Run on hardware

Example config.ini:

[policy]
name = gr00t

[policy.args]
host = 192.168.123.10
port = 5555
actions_are_relative = false

[embodiment]
name = g1_arms

[embodiment.args]
iface = eth0
hand_type = dex3
cam_server_address = tcp://192.168.123.164:5556
unattended = false

Then use the normal Inspect Robots run or eval command for your task. The policy server defaults to port 5555. The camera defaults to port 5556 so the two services do not collide.

Safety

Warning

A G1 arm-sdk target and actual-pose mismatch during an abrupt weight change can snap the arms at high speed. Never replace the measured-pose weight ramp with a direct weight flip.

On the first reset, the adapter reads the observed arm pose, seeds every commanded target from it, ramps arm-sdk weight from 0 to 1 while holding that pose, then streams to the zero home pose. Later resets read and reseed from the fresh pose before streaming home, with no weight change.

Close first opens both hands. It then streams the arms to rest_pose, or to the pose observed at close start when no rest pose is configured. Finally it ramps weight from 1 to 0 and disconnects. Disconnect is attempted even when a publish or ramp fails.

Warning

No public arm-sdk firmware watchdog is documented. If a process dies while weight is 1, the controller can keep holding its last target. The adapter registers both an atexit hook and a SIGTERM handler. SIGKILL cannot be intercepted. Keep an operator holding the remote within reach for every run.

Remote L1+A enters damping mode. The robot goes limp and physically sinks, so the operator must also be ready to support the robot and protect nearby people and objects.

Warning

Stock Isaac-GR00T at the pinned N1.7 seam decodes relative arm outputs to absolute physical units on the server. Keep actions_are_relative=false for that server. Set it to true only for an older or custom server that returns offsets. A mismatch cannot be detected by compatibility checks and can cause runaway targets. Staff the stop control and slow-jog every new server build.

When relative conversion is enabled, every chunk row is added independently to the same observed arm anchor. It is never cumulatively summed, and the hand slots are never modified.

Warning

control_hz must match the checkpoint data frame rate. A compatible shape does not prove compatible timing. Verify the dataset rate before motion.

Before the first grasp, bench-verify Dex1 polarity at low speed. The cited xr_teleoperate source maps 0 rad to closed and 5.4 rad to open, so this package maps normalized 1 to 5.4 rad. Hardware revisions and calibration can differ.

Always run preflight, clear the workspace, verify camera orientation, inspect the measured pose, and perform a slow single-joint jog before policy control.

Configuration

G1 embodiment

Field	Default	Meaning
iface	eth0	DDS network interface, or None for default routing
hand_type	dex3	dex1 gripper or dex3 three-finger hand
control_hz	10	Framework action rate
stream_hz	50	Synchronous arm publish rate
max_joint_speed	3.0	Per-joint hard speed cap in rad/s
weight_ramp_s	2.0	Blend-up and blend-down duration
kp_arm, kd_arm	60, 1.5	Shoulder and elbow gains
kp_wrist, kd_wrist	40, 1.5	Conservative package wrist gains
home_pose	zero arms, open hands	Reset target
rest_pose	None	Close target, or measured close-start pose
dex1_stroke	5.4	Full open motor stroke in radians
dex1_max_speed	2.7	Dex1 motor speed limit in rad/s
hand_deadband	0.05	Normalized on-change publish gate
dex3_thumb_swing	0.0	Closed-reference thumb0 swing
cam_server_address	tcp://192.168.123.164:5556	JPEG SUB endpoint
cam_timeout_s	5.0	Camera receive timeout
unattended	false	Skip readiness and scoring prompts

The arm limits come from the official 29-DOF G1 URDF, pulled 0.05 radians inward. The official 50 Hz arm example supplies the arm gains. The lower wrist gain is this package's bench-tuned conservative choice.

Dex1 defaults use kp 5.0 and kd 0.05. Dex3 defaults use kp 1.5 and kd 0.2. Dex3 motor ordering differs by side, as required by the Unitree driver. The open pose is zero. Closed reference poses are conservative interior values derived from the left and right dex3_1 URDF limits because xr_teleoperate does not publish fixed grasp poses.

GR00T policy

Field	Default	Meaning
host	127.0.0.1	PolicyServer host
port	5555	PolicyServer port
timeout_s	15	REQ send and receive timeout
actions_are_relative	false	Enable legacy anchor-add conversion
action_horizon	16	Maximum returned prefix
replan_interval	8	Inspect Robots chunk metadata
image_key	video.ego_view	Dotted wire template key
state_keys	G1 N1.7 mapping	Dotted state source templates
action_keys	G1 N1.7 mapping	Returned action assembly templates

The SourceSpec DSL supports ("packed", start, stop), ("hand", side), ("state", field_key), and ("const", dim, value). Dotted config keys are split at the first dot. Wire inner keys are unprefixed. Returned actions may use either unprefixed names or action.-prefixed names. Unknown returned keys, including locomotion outputs, are ignored.

The 16-D contract

Slots	Values	Units
0 to 6	left shoulder pitch/roll/yaw, elbow, wrist roll/pitch/yaw	rad
7	left hand	normalized, 1 open
8 to 14	right shoulder pitch/roll/yaw, elbow, wrist roll/pitch/yaw	rad
15	right hand	normalized, 1 open

The scalar hand contract is a deliberate v1 simplification. Dex3 expands the scalar along a fixed power-grasp path. Per-joint hand actions, locomotion, waist and neck control, 23-DOF G1 arms, GR00T-SONIC, simulation, UnifoLM-VLA, and lerobot-served policy backends are future work.

Development

uv venv
uv pip install -e ".[dev]"
uv run ruff check .
uv run ruff format --check .
uv run mypy
uv run pytest --cov --cov-report=term-missing

Hardware, camera, ZMQ, and server behavior are fully injectable. Package import requires only Inspect Robots and NumPy.

Citation

See CITATION.cff.

License

MIT. See LICENSE.