中文说明：LimX Luna（型号 HU_L04）人形机器人的机器人描述文件，27 个主动关节，包含 URDF / MuJoCo MJCF / USD 模型与网格，MJCF 和闭链 USD 中建模了踝部、腰部并联机构，可直接用于 MuJoCo、Isaac Sim、ROS。本仓库镜像自 GitHub limxdynamics/luna-description。问题与合作请联系 opensource@limxdynamics.com。

Mirrored as-is from limxdynamics/luna-description. Download: hf download limxdynamics/luna-description

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_{For partnership and procurement inquiries, contact opensource@limxdynamics.com}

luna-description

Part of the Luna humanoid open-source ecosystem. Where to start and the other Luna repositories: Luna quick start.

URDF, MuJoCo MJCF & USD models for the LimX Dynamics Luna humanoid robot (HU_L04). Provides simulation-ready robot descriptions for ROS, MuJoCo, and NVIDIA Isaac Sim / Isaac Lab.

Highlights

• Full-body humanoid, 27 actuated joints. Legs, a 3-DoF waist, a 2-DoF head and 5-DoF arms, with rotor_mass and gear_ratio per joint in the SRDF.
• Parallel linkages modeled faithfully. The ankles and waist are driven through parallel linkages; the MJCF expresses them with equality constraints and usd_parallel/ as true closed loops.
• One robot, every simulator. URDF for ROS, MJCF for MuJoCo, USD for Isaac Sim / Isaac Lab, all from the same geometry.
• Ready for learning pipelines. The MJCF ships actuators plus joint position/velocity and IMU sensors, and a kinematics-only variant for motion retargeting.

Try it in 30 seconds

No ROS needed:

git clone https://github.com/limxdynamics/luna-description.git
cd luna-description
pip install mujoco
python -m mujoco.viewer --mjcf=HU_L04_description/xml/HU_L04_01.xml

Available models

HU_L04	HU_L04 (parallel) Ankle linkages in blue, rendered from the MJCF with a translucent shank shell

Model	Description	URDF	MuJoCo MJCF	USD
HU_L04	Luna humanoid, 27 actuated joints	urdf/HU_L04_01.urdf	xml/HU_L04_01.xml	usd/HU_L04_01.usd
HU_L04 (parallel)	Same robot with the ankle and waist parallel linkages modeled as closed loops	—	—	usd_parallel/HU_L04_01.usd

Note: Luna's ankles and waist are driven through parallel linkages. URDF cannot represent closed kinematic loops, so the URDF and the matching usd/ model use a serial approximation in which the ankle and waist joints are driven directly. The MJCF models the linkages with equality constraints, and usd_parallel/ models them as true closed loops for Isaac Lab.

Joint layout

Group	DoF	Joints
Legs	6 × 2	hip_pitch, hip_roll, hip_yaw, knee, ankle_pitch, ankle_roll
Waist	3	waist_yaw, waist_roll, waist_pitch
Head	2	head_yaw, head_pitch
Arms	5 × 2	shoulder_pitch, shoulder_roll, shoulder_yaw, elbow, wrist_yaw
Total	27

Leg and arm joints are prefixed left_ / right_, e.g. left_knee_joint.

MJCF contents

File	Actuators	Sensors	Parallel linkages
HU_L04_01.xml	27	Joint position and velocity for all 27 joints, base IMU (orientation, gyro, accelerometer)	6 <connect> constraints in <equality>: two per ankle, two for the waist
HU_L04_01_vis.xml	—	—	— (kinematics only, for motion retargeting)

Directory structure

HU_L04_description/ contains:

Directory	Contents
urdf/	URDF + SRDF (per-joint rotor_mass and gear_ratio)
xml/	MuJoCo MJCF: HU_L04_01.xml (full dynamics) and HU_L04_01_vis.xml (kinematics only)
usd/	NVIDIA USD files, serial approximation consistent with the URDF, + configuration/ subdirectory
usd_parallel/	NVIDIA USD files with the parallel linkages modeled as closed loops, + configuration/ subdirectory
meshes/	STL mesh files
world/	Gazebo world file (empty_world.world)
CMakeLists.txt	ROS package build file
package.xml	ROS package manifest

Usage

ROS 1 / 2

The description builds as the ROS package HU_L04_description on both ROS 1 (catkin) and ROS 2 (ament).

cd <workspace>/src
git clone https://github.com/limxdynamics/luna-description.git
cd ..
catkin_make  # or colcon build

The URDF references meshes as package://HU_L04_description/meshes/.... Outside ROS, point your loader's package path at the repository root, or use the MJCF / USD files directly.

MuJoCo

python -m mujoco.viewer --mjcf=HU_L04_description/xml/HU_L04_01.xml

For motion retargeting, load HU_L04_01_vis.xml instead.

Isaac Sim / Isaac Lab

Import the USD file from HU_L04_description/usd/HU_L04_01.usd via Isaac Sim's reference assembly. Use HU_L04_description/usd_parallel/HU_L04_01.usd instead if you need the closed-loop parallel linkages.

Both .usd files are thin wrappers that reference the assets in the configuration/ folder next to them, so copy the whole directory rather than the .usd file alone.

Related repositories

luna-beyondmimic — BeyondMimic motion tracking training for Luna (Isaac Lab).

License

Apache License 2.0 — see LICENSE and NOTICE.