RESOLUTE™ absolute optical linear and absolute optical rotary (angle) encoder system

Get the RESOLUTE Data Sheet here

RESOLUTE is a true absolute, fine pitch optical encoder system that has excellent dirt immunity, and an impressive specification that breaks new ground in position feedback. It is the world’s first absolute encoder capable of 27-bit resolution at 36,000 rev/min. It has an astonishing market-leading resolution of just 1 nanometre at up to 100 m/s for both linear and angle encoding applications.

RESOLUTE reads a unique single-track optical scale and offers further attractive benefits to machine designers by acquiring absolute position immediately upon switch-on, without the need for battery back-up. This completely eliminates the need for reference returns. Unique combinations of ruggedness, ultra-high speed and exceptional resolution mean that RESOLUTE is already attracting high levels of interest from manufacturers of high-performance lathes as well as slower-moving axes requiring the highest levels of precision and motion control integrity.

RESOLUTE can serve this wide range of markets because it offers more than just raw speed and high resolution. The RESOLUTE absolute encoder uses sophisticated new optics to read the fine pitch 30 µm scale with impressive low noise levels (jitter to 7 nm RMS) for outstanding positional stability, while the enhanced detection method intrinsically provides a very low sub-divisional error (SDE) of ±40 nm. The result is better surface finish of machined parts from CNC machine tools, better scanning and velocity control, and rock-solid servo stiffness on linear motors or rotary direct-drives when holding position.

RESOLUTE does not follow the conventional technique of using dual tracks side-by-side (one incremental, one absolute) which inherently suffer de-phasing problems when small amounts of angular misalignment are introduced. Instead, this new absolute encoder features a single track, optical absolute scale, combining both the absolute position and embedded phase information into one single code. This technology provides RESOLUTE with far wider set-up tolerances for quick and easy installation and superior long-term reliability, even if the motion axes settle or move over time. To further aid installation and diagnostics, there is an integral set-up LED on the readhead.

The linear encoder version of RESOLUTE is available with a comprehensive range of scale options. RELA Invar spars offer “zero” expansion and ±1 µm accuracy on lengths up to 1 m. For high performance on long axes and significantly more robustness than glass scales, RSLA stainless steel spars have a total accuracy of ±4 µm over 5 m. Plus, for the quickest and easiest installation there’s FASTRACK™ and RTLA tape scale with ±5 µm/m accuracy.

Angle encoder options are also well catered for; RESA rings are bolt-hole compatible with Renishaw’s leading SiGNUM™ RESM rings and are offered in a standard range of diameters from 52 mm to 550 mm, with even larger size options available to order. Like the SiGNUM RESM, RESA rings feature large through-holes for easy design-in and a patented taper mount for quick, easy and precise adjustment of eccentricity, whilst minimising shaft preparation costs.

Ultimate reliability is assured with RESOLUTE’s IP64 sealed readhead with wipe-clean recovery. The precision optics give excellent immunity to dirt on the scale, which is further enhanced by extensive redundancy in the scale code. Safety is assured by a built-in separate and independent position checking algorithm. This actively checks every reading, ensuring any potential problem is flagged long before it reaches the controller. The revolutionary readhead also incorporates a temperature sensor to measure heat build-up giving extra system protection, by signalling an alarm condition if head temperature rises above +80°C. This alarm is in addition to the signal monitoring, position-checking and speed monitoring that is carried out constantly inside the readhead.

The RESOLUTE absolute encoder uses purely serial communication resulting in exceptional noise immunity. It is available with a variety of protocols to enable easy connection to a wide range of industry-standard controllers, drives, DROs and PC counter cards. Potential customers are advised to check with Renishaw for the latest list.

For more information, pricing or availability about Renishaw's RESOLUTE series or any other product, call an MSI Tec Sales Engineer today at (866) 397-7388.

New SiGNUM™ Intelligent Encoder Series from Renishaw

Renishaw's new SiGNUM™ encoder range offers high speed, reliable, non-contact performance combined with advanced features including the IN-TRAC™ auto-phase optical reference mark. The first offering from this range is the RESM optical angle encoder, which comprises the RESM ring, SR readhead and Si interface. The RESM is a one-piece stainless steel ring  with 20 µm scale marked directly on the periphery. It features the IN-TRAC™ optical reference mark, which is repeatable, regardless of direction, at operational speeds over 3,600 rev/min (Ø52 mm) and up to 85°C.

The RESM angle encoder boasts impressive performance; with accuracy to ±0.5 arc second and resolution and repeatability to 0.02 arc second, it suits the most demanding precision applications. The low profile ring is available in a wide range of sizes (Ø52 mm to Ø413 mm) and line counts, all of which feature a large internal diameter for flexible integration. In addition, Renishaw's patented taper mount provides error compensation and easy installation. Consequently, the RESM's low mass, low inertia design will not compromise system accuracy or dynamic performance.

The SR readhead offers high speed, high temperature performance, (operational up to 85°C and over 3,600 rev/min). Like all Renishaw encoders, it benefits from unique filtering optics, which provide excellent immunity to dirt, dust and scratches. In addition, the RESM encoder uses SiGNUM™ intelligent signal processing to ensure excellent reliability and cyclic error (typically < ± 40 nm), whilst comprehensive SiGNUM™ software enables optimum set-up and real-time system diagnostics via a PC's USB port.

Precision rotary axes on machine tools require reliable and accurate encoders for angular position feedback. The low profile RESM offers exceptional accuracy in a compact and easy-to-install format. While the large internal diameter simplifies the routing of cables and other supplies through the machine, the Si interfaces can be mounted remotely and a small rugged connector on the readhead cable allows easy feed-through where access is restricted. In addition, the non-contact, modular RESM is taper locked to the machine's shaft, ensuring a compact table design and the elimination of coupling losses, oscillation, shaft torsion and other hysteresis errors that plague sealed encoders.

Encoders... high speed, high accuracy

Renishaw offers an extensive range of high speed linear encoders, easy set-up XY encoders, rotary encoders and a range of interpolators.

Renishaw laser encoders have an intrinsically high resolution which, combined with a system architecture that eliminates Abbe error, provide the highest possible positioning accuracy. Laser encoders offer precision feedback for a variety of applications, ranging from long axis machine tools to X-Y wafer inspection systems.

Optical linear and rotary (angle) encoders offer easy installation and set-up, with many patented features including filtering optics and a set-up LED that remove the need for oscilloscopes and other complicated set-up equipment. Optical encoders are applied in almost all sectors of industry including metrology, motion systems, electronics, semiconductor handling, medical, scanning/printing, scientific instruments, space research, photography and specialist machine tools.

Interferometer Based Encoders... for the ultimate accuracy in linear position control

The laser interferometer is used to determine the accuracy of CMMs, machine tools, and other industrial and scientific applications requiring accurate measurement and calibration. The principle of laser measurement is based on the International Standard for the metre - the speed of light*. Its novel design features offer the ultimate in flexibility of operation, portability and software/hardware interfacing.

The system configurations and options available allow many operating parameters to be checked and calibrated quickly and easily.

The latest Windows based measurement and analysis software, together with an innovation laser beam steering optic, makes the set-up of the laser system even easier.