 | Encoder ottici assoluti RESOLUTE™ - FunzionamentoAl momento, questa pagina non è disponibile nella lingua scelta. È possibile visualizzare una traduzione automatica realizzata con Google Translate. Renishaw declina qualsiasi responsabilità relativa alla fornitura di tale servizio e specifica di non avere controllato la traduzione. RESOLUTE’s astonishing performance is the result of a sophisticated, reliable and completely unique method of operation. Think of the readhead as an ultra-fast miniature digital camera, taking photos of a scale that consists of a long, non-repeating bar code. RESOLUTE analyses these photos to determine position to resolutions as small as 1 nanometre (1 billionth of a metre) and with remarkable low noise (jitter) and SDE (Sub-Divisional Error, the error within a scale grating period). This provides encoder feedback of superior fidelity, to ensure smoother velocity control and rock-solid positional stability. Absolute position data capture
The controller sends a 'request' word incorporating a pre-defined rising or falling edge of a critical data bit that instructs the readhead to freeze position count, effectively 'time-stamping' the data capture. At this point, RESOLUTE flashes a custom-designed LED light source and takes a photo of the scale. Crucially, the variation in the time between the critical bit edge and photo capture is controlled to within a few nanoseconds – one of the essential features that makes RESOLUTE perfectly suited to very high performance motion systems. The light and dark lines are captured by a high-speed detector that is custom-designed specifically for RESOLUTE eliminating undesirable compromises in performance. Absolute position data analysisThe information from the detector is flashed at approximately 1 gigabit/second to a state-of-the-art DSP (Digital Signal Processor) that analyses the photo to decipher all the complex aspects of code redundancy and cross-checking, focusing and motion blur, thus rejecting the effects of dirt and contamination. This analysis is so advanced that it can even calculate position in cases where parts of the code appear to the human eye to be completely obliterated by particulate contamination and even more impressively, overcome the light-scattering effects of oily or greasy smears that usually raise alarms. Absolute position data validationExcellent dirt immunity is not all; RESOLUTE provides security and safety by constantly running a built-in separate and independent position-checking algorithm, to actively check every reading thus ensuring that any potential problem is flagged long before it reaches the controller. RESOLUTE then sends the checked and verified position data back to the controller. Stop the clock!This entire process of operations and calculations take less than 40 microseconds from start to finish. The activity doesn’t even stop there, whilst it’s waiting for the next request, the DSP calculates the optimum set-up for the next photo for the conditions and speeds being experienced, readying itself for the next position request. High speed operation meets ultra-fine resolution
RESOLUTE monitors the speed of the axis and varies the LED flash parameters accordingly. This is one of the keys to achieving exceptionally low jitter, at medium / low speeds and at stand-still, on the same encoder that can hit 100 metres/second (36000 rev/min on a 52 mm ring). RESOLUTE can even be switched on at high speed and yet it automatically optimises itself in a few milliseconds – considerably less time than the 250 ms or so that it takes the servo amplifier to power-up reset! The single-track advantage of RESOLUTE's absolute optical scale
Renishaw’s solution was to incorporate the absolute position data and phase information into one single code. When combined with advanced optics, the tolerance to yaw, pitch and roll has been significantly increased. RESOLUTE readheads have a guaranteed yaw, pitch and roll tolerance of ±0.5°. Typical yaw tolerance, to the point where an alarm is triggered, is approximately ±1.5°. The optics also provide a very large rideheight tolerance of ±150 microns. De-phasing still does not occur. Combined with the impressive dirt immunity, RESOLUTE assures true long-term reliability. More about RESOLUTE...Data sheetsInstallation guides
3D models (step format)Videos |
RESOLUTE communicates in purely serial format, in a variety of industry-standard 
RESOLUTE’s performance is the combination of ultra-fine resolution and high speed. How is this possible?
RESOLUTE was designed from the outset as a non-contact encoder. The traditional arrangement of two or more tracks was rejected by the development team early on due to its liability to de-phase when only tiny amounts of yaw are introduced (approximately 0.02°). For a non-contact encoder, multi-track arrangements were deemed unreliable and impractical.