LeRobot Humanoid Models

This repository contains the URDF models for the LeRobot humanoid project, along with a few minimal scripts to check URDF sanity and load the models in simulation.

These models are intended as an early-stage research platform for humanoid robotics, with a strong focus on rapid iteration and real-world validation.

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⚠️ Current Status (Early Prototype)

Please note that this is a very early version of the models:

• The default joint configuration of the URDF is currently not symmetric.
  (Do not expect clean or mirrored values yet.)

• The mass distribution of the upper body is not yet realistic and will be updated in future versions.

• Geometry, inertias, and kinematic structure are still evolving as the hardware design iterates.

Despite this, the models are already usable for:

• kinematics,
• basic dynamics,
• control and locomotion prototyping in simulation.

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CAD Model (Onshape)

The corresponding CAD model of the humanoid robot is available on Onshape:

https://cad.onshape.com/documents/fb645318a27646d1d8840be6/w/d1cae8805fb652b4d1614997/e/70edb54994a0fe82dd64a212

This CAD model reflects the current hardware design iteration and is provided to support:

• mechanical inspection,
• dimensioning,
• hardware replication,
• and future co-design work.

Please note that the CAD and URDF may temporarily diverge as both evolve during rapid prototyping.

Included Models

This repository currently provides two URDF variants:

1) urdf/bipedal_platform

• A 12-DoF URDF model of a bipedal robot
• The upper body is represented using fixed joints
• Intended for early locomotion experiments

A short video of this platform walking is included:
walk.mp4

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2) urdf/lerobot_humanoid

• A 20-DoF URDF model including:

  • legs
  • arms

• Intended as the first full-body humanoid prototype

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Reference Frames

Both URDFs define the following standard frames:

Feet

• foot_left
• foot_right

Lower torso

• torso

Hands

• hand_left
• hand_right

These frames are meant to be used as contact points and end-effectors for control and planning.

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Example Code

This repository includes minimal example scripts to:

• load the URDF,
• check basic model consistency,
• visualize the robot.

These scripts are only meant as sanity checks and lightweight usage examples.

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Installation (for testing the example code)

Requirements

The required Python environment is described in environment.lock.

In addition, the following external dependencies are needed:

• A fork of Crocoddyl
  https://github.com/LudovicDeMatteis/crocoddyl/tree/topic/contact-6D-closed-loop

• A fork of Sobec
  https://github.com/LudovicDeMatteis/sobec/tree/iros-2025

• meshcat (for visualization)

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