Renishaw earlier this year received a Queen's Award for Enterprise 2015 in the Innovation category for its Resolute absolute position encoder system. This prestigious award follows a rigorous and highly competitive entry process and is awarded only to top UK businesses.
Renishaw's Resolute encoder system won the award by demonstrating a uniquely innovative design with outstanding commercial success over the last five years. Resolute is described as the world's first single-track fine-pitch optical absolute encoder, and market-leading technology. The readhead captures a near-instantaneous image of a coded measuring scale, which comprises a single data track with a non-repeating barcode-like strip of 15um-wide light and dark lines. Unlike other products in the market, complicated guiding arrangements are not needed to maintain alignment between the readhead and scale, which eliminates mechanical hysteresis and measurement errors.
Four of the most innovative features of Resolute's design and production process include:
First is a new imaging-based system, rather than a traditional interference-based optical technology, comprising a lens system for the best stability and accuracy of metrology. The readhead uses specially designed custom components including a high-reliability point-source LED, an imaging lens, a beam splitter and custom 320-pixel linear image sensor capable of processing 150,000 frames per second. Advantages of this system include rapid position acquisition on demand, exceptional dirt immunity as a result of significant absolute scale code redundancy, low sub-divisional error (SDE) of +/-40nm and low jitter (noise) of 10nm RMS.
Secondly, novel and fast algorithms for increased safety and position reliability. Two independent algorithms operate within the readhead to compute its position with respect to the scale, giving high confidence that the declared position will be correct at all times.
Thirdly, development of new scale manufacturing techniques to enable the production of a single barcode-like pattern on both linear and rotary scales – allowing, for the first time, scale manufacturing capability beyond an accuracy of 1um for linear scales and below one arc-second for rotary scales.
Fourthly, exceptional dynamic performance that matches the performance benefits of current incremental systems but using only a single absolute track, and breaks the speed-resolution trade-off that plagues traditional encoders.
Other award-winning added benefits of Resolute include eliminating the need for homing operations, large installation tolerances, high-speed traversing rates, and versatile readhead and scale options.
Resolute specifications and options
Resolute is available with both linear and rotary scale types and is compatible with a range of 'open' and proprietary serial protocols including Siemens Drive Cliq, BiSS, Fanuc, Mitsubishi and Panasonic for connection to a wide range of industry-standard motor drives and controllers.
In rotary (angle) configuration, Resolute is capable of 32-bit resolution at 36,000rpm or, in linear format, 1nm at speeds of 100m/s and lengths to 10m. This results in: better surface finish of CNC machined parts; better scanning and velocity control; and exceptional servo stiffness on linear motors or rotary direct-drives when holding position. Resolute is now also available in ultra-high vacuum (UHV) and extended temperature range (ETR) compatible variants for advanced applications.
Resolute has CE approval, RoHS compliance, and is manufactured by Renishaw under strict quality controls that are certified to ISO 9001:2008. Resolute, like all Renishaw encoders, is backed by a global sales and support network.
Follow the link to find out more about the Resolute absolute position encoder system that received the Queen's Award for Enterprise 2015.