Dexforce W1

Dexforce W1#

Dexforce W1 is a dual-arm humanoid robot developed by DexForce Technology Co., Ltd.

Key Features#

Supports dual 7-DOF arms
Supports version-owned asset layouts and calibration parameters
Configurable left/right hand brand and version
Flexible URDF assembly and simulation configuration
Compatible with SimulationManager simulation environment

Configuration with `DexforceW1Cfg.from_dict`#

DexforceW1Cfg.from_dict is the single public construction entry point. A W1 configuration always describes the complete chassis, torso, head, eyes, wrist cameras, and both arms for one robot version.

Parameters:

hand_types: Dict specifying hand brand for each arm side (LEFT/RIGHT).
hand_versions: Dict specifying hand version for each arm side.
with_default_eef: Whether to install the registered default end effectors.
hand_attach_xposes: Optional hand-specific mounting transforms.

from embodichain.lab.sim.robots import DexforceW1Cfg

cfg = DexforceW1Cfg.from_dict(
    {
        "uid": "dexforce_w1",
        "version": "v025",
        "hand_types": {
            "left": "BRAINCO_HAND",
            "right": "BRAINCO_HAND",
        },
        "hand_versions": {"left": "v021", "right": "v021"},
    }
)
robot = sim.add_robot(cfg=cfg)
print("DexforceW1 robot added to the simulation.")

Arm Joint Design: Mirrored Configuration#

DexforceW1’s left and right arms are designed with mirrored joint configurations. This means the joint angles for the left and right arms are symmetric but opposite in sign for certain axes, making it easier to coordinate bimanual tasks and maintain natural robot postures.

Example: Setting Arm Joint Positions#

import numpy as np
# Set left arm joint positions (mirrored)
robot.set_qpos(qpos=[0, -np.pi/4, 0.0, -np.pi/2, -np.pi/4, 0.0, 0.0], joint_ids=robot.get_joint_ids("left_arm"))
# Set right arm joint positions (mirrored)
robot.set_qpos(qpos=[0, np.pi/4, 0.0, np.pi/2, np.pi/4, 0.0, 0.0], joint_ids=robot.get_joint_ids("right_arm"))

This mirrored design simplifies motion planning and ensures that both arms can perform coordinated or symmetric actions efficiently.

Type Descriptions#

Type	Options / Values	Description
`DexforceW1HandBrand`	`BRAINCO_HAND`, `DH_PGC_GRIPPER`, `DH_PGC_GRIPPER_M`	Hand brand
`DexforceW1Version`	`V021`, `V022`, `V025`	Release version
`DexforceW1HandVersion`	`V021`	External hand/gripper asset version
`DexforceW1ArmSide`	`LEFT`, `RIGHT`	Left/right hand identifier

Unified asset layout and version extension#

V022 and V025 use one unified Hugging Face archive per release:

dexforce_w1/<version>/w1.zip
└── w1/
    ├── robot.urdf
    ├── chassis.urdf
    ├── torso.urdf
    ├── head.urdf
    ├── left_arm.urdf
    ├── right_arm.urdf
    ├── visual/
    └── collision/

The runtime downloads each release archive once. Direct FK/IK uses robot.urdf or the arm URDFs, while configurable robot assembly reads all components from the same extracted directory. V022 and V025 assets are resolved through the registered Hugging Face dataset archives and the shared asset cache.

Version-owned end-effector offset#

Different arm revisions may place the physical mounting surface at different positions relative to the arm ee frame. This difference belongs to the W1 revision, not to a BrainCo hand, DH gripper, PIKA gripper, or any other end-effector.

W1VersionSpec.default_eef_attach_xpos is the single source of truth for this revision offset:

Version	Left arm	Right arm
V021	Identity	Identity
V022	Identity (provisional; calibration required)	Identity (provisional; calibration required)
V025	`+0.012 m` along the `ee` frame Z axis	`+0.012 m` along the `ee` frame Z axis

The final assembly transform and solver TCP are derived as follows:

final_attach_xpos = version_attach_xpos @ eef_attach_xpos
final_tcp = version_attach_xpos @ solver_tcp

Therefore, the V025 offset affects both the assembled end-effector position and FK/IK results. The offset is also applied when callers provide a custom hand_attach_xposes value, a custom left_hand/right_hand component transform, or an explicit arm TCP through DexforceW1Cfg.from_dict. Serialization removes the derived offset and restores it on loading, so a configuration round trip does not apply the offset twice.

Do not manually add the 12 mm correction to an end-effector transform or TCP. Those values must describe the end-effector relative to the standard mounting surface; the W1 version layer adds the robot revision correction.

One DexforceW1Version selects the complete W1 robot release. Mixed body/arm versions are intentionally unsupported because their assets, kinematics, TCP, and camera calibration must remain consistent.

Robot and hand versions are independent. DexforceW1Version selects the W1 body, arm assets, kinematics, and flange calibration. DexforceW1HandVersion selects an external hand or gripper asset from embodichain/lab/sim/robots/dexforce_w1/hand_specs.py.

The currently released BrainCo hand and DH gripper registrations all use DexforceW1HandVersion.V021. Therefore W1 V021, V022, and V025 select hand V021 by default. This is an explicit default, not a compatibility alias keyed by the robot version. A future hand release is added by registering a new hand version and hand spec; it does not require adding aliases for every W1 robot version.

To add another W1 revision:

Register the new DexforceW1Version value and dataset archive.
Add one W1VersionSpec entry in embodichain/lab/sim/robots/dexforce_w1/specs.py.
Register component URDF paths and the full-robot URDF path.
Set the arm kinematic parameters and default_eef_attach_xpos for both sides. Use identity only after confirming that the arm ee frame is already at the physical mounting surface.
Verify that the same version offset is present in both the assembled end-effector pose and the final FK/IK TCP.
Validate hand/gripper mounting, wrist cameras, FK/IK, VR teleoperation, and real2sim task regression.

To add another hand release:

Add a DexforceW1HandVersion value.
Register each supported brand and side in hand_specs.py, including its URDF, joint names, root/end links, and mounting transform.
Select it explicitly through hand_versions; an unregistered version fails during config construction.

Control parts, assembly, TCP selection, analytical parameters and FK/IK then use the version specification without revision-specific branches.