Gearcoder

Hollow multi-turn absolute position encoder for robots

This is an absolute linear encoder that uses a permanent magnets track of a linear motor in place of a traditional scale. Compatible with Mitsubishi and Panasonic servo systems, it offers a resolution of less than 1μm, supports speeds exceeding 3m/sec, and achieves a repeatability of 10μm. This is an absolute linear encoder, so no initial pole detection or homing operation is required.

Design the disk as you want

Flexible disk design allows for in-house manufacturing
No restrictions on the number of teeth for gear disks.
Supports various disk types through parameter configuration
Disk settings can be configured directly from the controller

Multiple Sensor Serial Connection (BiSS C)

Receiving Data from Multiple Sensors via a Single Cable
Supports up to 8 sensors in a daisy-chain configuration with built-in I/O ports (BiSS-C).
Simplified cabling (9-wire)

battery-buffered absolute position sensor

Multi-turn absolute positioning with battery
Capacitor application, battery life of more than 20 years
Using multiple sensors with one battery (lifespan review based on usage conditions)

High resolution up to 25 bit

Up to 25-bit high single-turn resolution.
High positional accuracy achieved through precision machining of gear-based scales.
Multi-turn resolution of 16 bits or higher.

Large hollow disk, no cost for initial production

Hollow gear and magnetic disk implementation.
No initial investment for molds or similar.
Various disk sizes tailored to joint requirements.
Multiple standard disks provided.

Built-in functional safety

Supports BiSS Safety protocol.
Built-in functional safety features with redundancy (e.g., CRC-16).
Resistant to disk damage and foreign contaminants.

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Combination of three gear-type encoders and one ultra-compact magnetic encoder
Demonstration for robot teaching applications
Dedicated receiver board for simultaneous reception from four position sensors
Implementation of a virtual fence using an ultrasonic sensor

Daisy-chain connection of multiple Gearcoders (including power, battery, and communication lines).
Simultaneous reception of position data from 6 or more Gearcoders using a single cable(9-wire, including FG)
Implementation of the open-source BiSS-C protocol.

Connector change model_connection diagram.jpg

Absolute position sensing maintained using a battery during power outages
Low-power Hall sensor enables absolute position detection during outages, ensuring a battery life of 5 to 10 years or more
Upon restoration of main power, high-resolution position data is combined and transmitted as high-precision absolute position via serial communication

Gearcoder and gear assembly tolerances
- Air gap between gear and IC surface: 0.4–0.6 mm
- Center point deviation (C) from gear: ±0.1 mm
- IC height deviation (H) from gear: ±1 mm (IC must not deviate)
- Parallelism with gear: ±0.1 mm