Product Introduction

1. Product Overview

Wuji Hand is a bionic dexterous hand with 20 active degrees of freedom developed by WUJI TECH, designed for various application scenarios such as scientific research, robot integration, and human-computer interaction.

2. Product Parameters

The Wuji Hand core technical parameters table covers structural design, drive control, load performance, dynamic response, and electrical characteristics for product selection, simulation modeling, and application integration.

3. Product Structural Features

This section introduces the overall structural design of Wuji Hand, communication and power interface layout, as well as the naming conventions and motion parameters of each degree of freedom, helping users understand the mechanical structure and usage specifications of the product.

3.1 Structural Schematic

Wuji Hand adopts a five-finger bionic structural design, with each finger containing multiple joints for flexible motion. The figure below shows the overall structure and main components:

• A to E in the figure correspond to:
  • A: Thumb
  • B: Index
  • C: Middle
  • D: Ring
  • E: Little
• Numbers 1 to 5 correspond to commonly used anatomical region identifications:
  • 1: Distal phalanges
  • 2: Intermediate phalanges
  • 3: Proximal phalanges
  • 4: Metacarpals
  • 5: Carpals

3.2 Wuji Hand DOF Configuration

The figure below shows the anatomical naming and corresponding positional relationships of each joint of Wuji Hand, helping users understand the functional positioning of each degree of freedom.

Numbers 1 to 6 in the figure correspond to:

• 1: CMC1
• 2: CMC2
• 3: MCP1
• 4: MCP2
• 5: PIP
• 6: DIP

3.3 DOF Motion Direction and Range

The four-finger structure is consistent, with a single finger full length of approximately 157 mm; the thumb module structure is slightly different, with a single finger full length of approximately 130 mm. The figure below uses the thumb and little finger as examples to illustrate the motion direction and angle range of each degree of freedom:

• Thumb
  • 1: Carpometacarpal abduction/adduction, motion range approximately 100°
  • 2: Carpometacarpal lateral swing, motion range approximately 80°
  • 3: Flexion/extension, motion range approximately 130°
  • 4: Flexion/extension, motion range approximately 130°
• Little Finger
  • 1: Flexion/extension, motion range approximately 125°
  • 2: Lateral swing, motion range approximately 60°
  • 3: Flexion/extension, motion range approximately 130°
  • 4: Flexion/extension, motion range approximately 130°

3.4 Communication and Power Interface Schematic

Wuji Hand achieves data communication with the host computer through a USB-C interface while supporting external power supply. The figure below shows the communication and power interface positions and connection methods of Wuji Hand:

• Numbers 1 to 3 in the figure are:
  • 1: USB data cable connection end (plugged into the dexterous hand device)
  • 2: USB data cable other end (connected to host computer or robot controller)
  • 3: XT30 power interface for external power supply

4. Product Electrical Characteristics

4.1 Pin Definition

4.2 Indicator Light Reference Table

An RGB status indicator sits on the lower back of the hand. It provides real-time feedback on power supply and system operation.

The meanings corresponding to each status are shown in the table below:

Indicator Light Color		Status Symbol	System Phase Description	Description
	No Light	OFF	Powered off/unpowered state	Power supply not connected or main power failure
	Blue Solid	Bootloader	Firmware update or bootloader	Device is in bootloader. If device is performing firmware upgrade, strictly prohibit power disconnection or cable reconnection to avoid system damage
	Green Flashing	Standby	Normal standby	Power supply normal, system normal, not connected to host computer or SDK
	Green Solid	Running	Normal operation	Power supply normal, system started, connected to host computer or SDK
	Yellow Solid	Warning	Device warning	System detected warnings such as high temperature, power fluctuation, and other non-fatal faults. Pause debugging and investigate the warning cause
	Red Flashing	Pre-fault	Fault warning	Warning of impending fault, such as temperature approaching overtemperature threshold
	Red Solid	Fault	Critical fault	Serious hardware/software fault (such as main MCU abnormality, communication out of sync, etc.). Disable immediately and troubleshoot via host computer (observe indicator light, terminal log, reset/factory restore)

5. Product Accessories Introduction

5.1 Product Accessories Table

Image	Name	Description
	12V 20A Power Adapter	Power supply
	Power Adapter AC Cable
	Impact-resistant Adapter	See 5.3 Impact-resistant Adapter
	Direct-mount Adapter	Connects Wuji Hand to user equipment (such as robot arm flange)
	Toolkit	Hex wrench Pry bar: for separating the latched impact-resistant adapter
	Accessory Kit	Socket head cap screws: M4x6, M5x10, M6x10 XT30 female connector
	USB A to USB C Cable	For communication between host device and Wuji Hand
	Tactile Sensing Glove (Optional)	See 5.2 Tactile Sensing Glove Whether it ships with Wuji Hand, and the left- or right-hand fit, depend on your order

5.2 Tactile Sensing Glove

The Tactile Sensing Glove is an optional tactile perception accessory for Wuji Hand. It targets research and engineering scenarios — sensing, data collection, human-machine interaction — and provides a unified hardware foundation for algorithm adaptation, simulation modeling, and multi-modal fusion.

• High sensing density: Full-palm uniformly distributed sensor array, more than 400 sensors, each independently capturing contact states; super-resolution further enhances perception
• High compliance: Fully flexible Nerve skin (flexible sensing skin) accommodates bending and stretching, forming a dynamic sensing array that conforms closely to objects

5.2.1 System Requirements

echo 'SUBSYSTEM=="usb", ATTR{idVendor}=="0483", MODE="0666"' | \
sudo tee /etc/udev/rules.d/95-wujihand.rules && \
sudo udevadm control --reload-rules && sudo udevadm trigger

5.2.2 Product Parameters

5.2.3 Connection

1. Connect the circle marker end of the bundled short data cable to the Brain Watch bridge port (circle marker). Route the other end around the inner wrist of Wuji Hand and connect it to the Wuji Hand communication port.
2. Use a USB-C (USB 2.0 or higher) data cable to connect to the PC — connect either USB-C end to the Brain Watch output port (triangle marker), and the other end to the PC.

5.2.4 Communication Interface

The product currently exposes a single communication interface, simplifying host integration.

5.2.5 Software Support

The official SDK provides full data access and device control, covering everything from algorithm validation to production deployment. See the SDK User Guide — Tactile Sensing Glove for the full API reference.

SDK interfaces

Two interfaces share a single backend and behave identically:

Core API capabilities

• Connection: connect() / disconnect() / is_connected(); multi-device addressing by USB serial number
• Frame reading: blocking read_frame(timeout_ms) or callback-based start_streaming(callback) / stop_streaming()
• Device info: get_device_info() (serial / hardware / firmware version), get_fw_build(), get_handedness()
• Diagnostics: get_diagnostics() (uptime, frame count, CRC errors, drops, USB resets), reset_counters()
• Runtime config: get_sample_rate_hz() / set_sample_rate_hz() (1–120 Hz), set_streaming(enable)
• Time sync: get_device_time(), sync_host_epoch(host_unix_ns) for multi-device alignment
• Lifecycle: reset_device() for soft reset
• Error handling: USB disconnection triggers DisconnectCallback; C++ raises ConnectionLostError, Python raises the corresponding exception

Joint operation

The tactile glove and Wuji Hand use independent USB transports and threads, so they can run in parallel within the same process (see example/joint_with_tactile.py) — enabling closed-loop scenarios such as tactile-driven motion control.

5.3 Impact-resistant Adapter

The impact-resistant adapter uses a twist-lock and slot locking structure to maintain a rigid connection under normal conditions. When subjected to external impact forces exceeding the safety threshold (such as robot arm loss of control or severe end-effector collision), Wuji Hand and the robot arm will trigger active separation to protect critical components (joints, motors, reducers, etc.) from damage. This design ensures improved reliability while minimizing maintenance and repair risks.

• Normal state: Twist-lock and set screws are tightened to ensure structural stability and prevent loosening due to daily vibration or minor impacts.
• Abnormal state: Automatically releases when exceeding the safety threshold, with Wuji Hand suspended by the safety chain to avoid secondary impact or falling hazards.

6. Installation and Removal

6.1 Installation Steps

Step 1: Remove the impact-resistant adapter from the packaging (left image), pull apart the four-claw latch and grooved flange (right image), remove the set screw and rotate the twist-lock counterclockwise to separate the upper and lower components.

Step 2: Use screws to connect the grooved flange to the user equipment (such as robot arm). The grooved flange provides two hole sizes, with matching screw sizes of M5×10 and M6×10. Use M4×6 screws to connect Wuji Hand to the four-claw latch.

Step 3: Insert the twist-lock into the four-claw latch and rotate clockwise until tight (gently pull the safety chain to verify the twist-lock will not slip out). Install the set screw. Align the four-claw latch with the positioning slot on the grooved flange, press down to latch, and the impact-resistant adapter installation is complete.

6.2 Precautions

6.2.1 Fastening Check

• Use recommended specification screws; screws of insufficient length or incorrect specifications are strictly prohibited
• It is recommended to tighten screws in a diagonal sequence to ensure even flange surface contact
• If possible, configure a recommended torque wrench according to screw specifications to ensure tightening torque meets standards

6.2.2 Maintenance and Inspection

• After each installation or removal, check whether the safety chain and twist-lock are flexible, unworn, and whether the attachment points are loose
• If impact-resistant release is triggered during operation, check whether installation screws are loose and whether the twist-lock locking mechanism is intact before reinstallation