The global site of the UK's leading magazine for automation, motion engineering and power transmission
19 May, 2024

Twitter link

EU project doubles reading range of any magnetic encoder

23 July, 2020

The German magnetic measurements specialist Bogen Electronic has announced a technology that, it says, will double the reading distance of any magnetic encoder.

The technology has been developed as part of a €2.775m ($3.2m) EU-funded project aimed at addressing the lack of cost-effective, high-accuracy absolute encoders.

The collaborative Masma (magnetic measurement with absolute single-digit micro accuracy) project includes partners from Austria (the University of Vienna) and Portugal (Insec Microsystems & Nanotechnologies). Its aim is to convert existing absolute measurement systems to modular encoders that can detect the absolute positions of various scale patterns, extend their sensing distances, and add smart functions such as using external correction factors.

The two-year project, due to finish in April 2021, was prompted by a shift in the position measurement and motion control market from incremental to absolute measurements. In contrast to incremental systems that measure positions relative to a start position, absolute systems provide a defined position value at start-up. However, the shift to absolute measurements is being held back by a lack of accurate, cost-effective sensing products.

Bogen believes that there is a potentially large market for absolute magnetic measurement devices with accuracies of 1–10µm. It calls this accuracy class “single-digit or short-single micron”. Such devices could be used in machinery, robots, printing presses and other applications.

One objective is to create a chip-based system for high-volume markets. Bogen has developed a digital scale-writing technique for producing the linear and rotary scales with various accurate magnetic patterns needed for absolute scales.

The first product to emerge from the Masma project is Bogen’s X-RMS rotational magnetic scale which can be used to double the sensing distance of any existing magnetic sensor, giving engineers more flexibility in their designs.

Bogen says that its X-RMS rotational magnetic scales can be double the sensing distance of any existing magnetic sensor

Tight assembly tolerances for multipole encoders are no longer a limitation. Instead of using rare-earth dipoles to achieve long reading distances with low accuracy, Bogen's multipole rings have accuracies that can be measured in arc-seconds.

“Increasing reading distances for high-accuracy applications has been very high on the wish list of our customers for a long time,” explains Bogen's managing director, Dr Torsten Becker. “The new X-RMS scales do just that and extend the envelope of magnetic encoders.

“Using the same sensing head with our new scale provides the same accuracy and functionality as before, but with a larger distance between them,” he continues. “We can now apply our unique magnetic pattern creation technology at much higher magnetic flux.”

Using a standard sensor read head with the X-RMS scale, the reading distance between sensor and scale can be doubled compared to a standard RMS scale, without any loss in function or accuracy, according to Bogen. It can be used to create rotational scales with diameters from 15–80mm, and with any incremental or absolute pattern for radial or axial encoders. Standard rotational scales can be produced from 3mm to 2.1m.

  • To view a digital copy of the latest issue of Drives & Controls, click here.

    To visit the digital library of past issues, click here

    To subscribe to the magazine, click here



"Do you think that robots create or destroy jobs?"



Most Read Articles