High performance rotary (angle) encoders for machine tools
December 2014
RESOLUTE™ adds the benefits of being a true absolute encoder. This means it acquires absolute position immediately upon switch-on, so the machine knows the exact orientation of the axis and motor commutation angle without the need for a reference (datum) return. This is particularly useful in the case of direct-drive rotary (torque) motors and upgrading to direct encoder feedback on gear-driven rotary axes.
What can RESOLUTE™, SiGNUM™ and TONiC™ do for you?
RESOLUTE, SiGNUM and TONiC rotary encoders help the world's leading machine tool manufacturers achieve optimum performance:
- Improve surface finish performance
- Increase accuracy
- Increase work output
- Reduce heat build-up
- Increase servo loop gains on direct-drive axes
- Simplify axis design
- Reduce cost of ownership
RESOLUTE, SiGNUM and TONiC encoders achieve these performance benefits because they have two major advantages over traditional enclosed encoders.
First, because they are non-contact, they eliminate backlash, shaft wind-up and other mechanical hysteresis errors that plague traditional enclosed encoders.
![TONiC™ readhead on RESM ring](/media/img/gen/359082b9c453432a8dee40f852bc877a.jpg)
Second, SiGNUM and TONiC apply dynamic signal conditioning including Auto Gain Control, Auto offset Control and Auto Balance Control to ensure exceptional signal purity. Therefore, Sub-Divisional Error (SDE) is controlled to ±30 nm (±0.06 arc seconds on 206 mm Ø RESM). RESOLUTE incorporates advanced optics that inherently control SDE to ±40 nm (±0.08 arc seconds on 209 mm Ø RESA).
The result? Significantly improved velocity ripple for better contouring performance.
Furthermore, for high-resolution axes demanding the ultimate precision control, Renishaw offers low noise variants of SiGNUM and TONiC encoders with reduced jitter, improving positional stability. RESOLUTE has inherent low noise (jitter) of <10 nm RMS.
Both the RESOLUTE absolute encoder and SiGNUM incremental encoder offer a variety of high-accuracy scale options that offer simple integration and quick, easy installation combined with linear encoder accuracies to ±1 µm and angle encoder accuracies to ±1 arc second.