Maintenance

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Safe Stop and Fault Recovery

Fault severity sets how the device stops, and communication loss, emergency stop, the fault-clearing reset, hazard zones, and the responsibility split for running with a robot arm each follow a fixed convention.

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Fault Severity and Stop Behavior

Decode a device error code with WujiHand2.describe_error(code). The result carries a severity level (severity) and a clear policy (clear_policy). Each severity maps to a stop behavior: Clear policies come in three kinds: AutoClear (clears itself once the cause is removed), ManualClear (needs a clear-fault call), and NonClearable (needs a power cycle, and if it recurs, stop using the device).

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Communication Loss Behavior

If communication with the host drops while the hand is enabled, the device stops the motors and reports a fault. It doesn’t resume motion on its own once communication returns—call enable() again (firmware v2.1.0 and later).

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Emergency Stop

• Software emergency stop: hand.emergency_stop() stops the whole hand immediately and takes no mask
• Hardware emergency stop interface: not available in this version

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Torque State After a Fault

A Warning doesn’t stop the device, so it keeps running. After a DeferredStop, ImmediateStop, or Fatal fault stops the device, the joints go limp. For the meaning of each level, see Fault Severity and Stop Behavior above. Assess the risk of dropping a held object in your application.

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Clear Faults and Reset Safely

1. Subscribe to joint_diagnostics to read the active error codes, then call info = describe_error(code).
2. If code is 0, no fault is active. Keep monitoring the device.
3. If info is None, retain the original error code and contact support to confirm how to handle it. Don’t continue with the fault-clearing steps below.
4. Otherwise, read cause and resolution from info, then address the reported cause.
5. Clear the fault: for AutoClear, wait for it to clear itself. For ManualClear, call clear_fault() (optionally with a 20-bit mask to target specific joints).
6. Enable again with enable(), and confirm the status light turns white solid.
7. For NonClearable (Fatal) faults, power-cycle the device. If the fault recurs, stop using the device and contact support.

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Hazard Zones

• Pinch points: the gaps between fingers and at the joints. Always run the hand with the soft pad and skin fitted, and keep clear while the hand moves
• Hot zone: the motor area in the palm. Don’t touch it directly after a high load
• Cable zone: the flex cables on the finger surface and the cables leaving the wrist. Avoid scratching and pulling

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Safety Responsibilities When Running With a Robot Arm

• The hand has no awareness of the arm’s motion planning. Arm-side collision detection, speed limits, and workspace isolation are the integrator’s responsibility
• The hand side provides its own over-torque, over-temperature, and communication-loss protection, and records impact detection events

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Maintenance and Consumables

The skin, soft pad, and whole fingers are user-replaceable, while board-level parts are not. Daily checks, storage, transport, and warranty each carry their own requirements.

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What You Can Service

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Daily Checks and Maintenance Intervals

Check before each day’s use:

• No visible damage, with the skin properly fitted
• No cable damage and no loose connectors
• The power-on self-check passes (the status light reaches white breathing)

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Storage and Transport

• Storage: power down and store in a dry environment, with the fingers extended flat in the box
• Transport: use the original packaging, which is designed for high-temperature, high-humidity, drop, stacking, and vibration conditions

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Warranty and Support

The warranty scope and repair process aren’t available yet and will be added later. If a prototype is damaged, contact your point of contact or [email protected] immediately.