Multi-DoF optical encoders
Multi-DoF (multiple degrees of freedom) optical encoder systems measure up to six degrees of freedom (6DoF). Find out how Renishaw's multi-DoF measurement technology, featuring its unique RXMA 1.5D scales, provide high-performance position measurement for dynamic motion applications.
Absolute control of dynamic motion applications
Renishaw has engineered a true-absolute multi-DoF encoder system, featuring one or more RXMA 1.5D scales, read by market-proven RESOLUTE™ absolute encoders. This combination offers advanced multi-DoF position measurement without the time-consuming homing cycles often required by incremental encoder systems. RXMA absolute scales use a low-expansion substrate for excellent thermal stability.
Built for high-performance applications
The absolute multi-DoF encoder system from Renishaw is ideally suited to high-performance motion systems. Highly dynamic applications such as XY stages used by the semiconductor industry require exceptional accuracy and repeatability to meet quality and productivity demands. By measuring multiple degrees of freedom along each axis, machine builders can dynamically measure error sources such as the straightness of linear guideways. Renishaw multi-DoF encoders enable in-process compensation of the resulting translation and rotation errors, helping to maintain process capability and improve component yields.
True X and Y axis measurement
RXMA30 scales feature two orthogonal scale patterns, enabling direct position measurement in the X and Y axes. Independently measuring the primary linear degrees of freedom can provide some metrology benefits. For example, measurements in the Y axis are immune to any thermal expansion detected in the typically longer X axis.
Easy electrical and mechanical integration
Renishaw's multi-DoF approach combines distinct, separate axes to enable easier integration with the control loop. Direct measurement of the X and Y axes enables convenient signal processing and compatibility with a range of serial interfaces.
Machine designers can position readheads to suit the requirements of the application, as individual readheads act independently of each other. A combination of end-exit and side-exit cables can also be configured, helping to simplify cable routing for each axis.
Absolute multi-DoF encoder systems: readheads and scales
Multi-DoF encoder systems consist of at least one 1.5D scale and two or more readheads. The maximum scale length for the absolute readhead and scale is shown below:
RESOLUTE™ readhead (30 µm pitch) High accuracy High speed |
RXM Multi-DoF scale 1.5D glass spar scale Low expansion High repeatability X axis = 350 mm Y axis = 4 mm |
Complete multi-DoF metrology solutions from Renishaw
Renishaw is your metrology partner for high-performance motion systems, with a range of technologies available to meet the specific needs of your application.
Renishaw offers a variety of multi-DoF measurement solutions: laser calibrators, optical encoders, and laser encoders.
- The XM-60 and XM-600 multi-axis calibrators enable manufacturers to measure errors in six degrees of freedom to establish a highly accurate process foundation.
- Multi-DoF absolute encoder solutions ensure exceptional in-process position measurement and monitoring to maintain optimum performance in operation.
- The RMAP multi-axis periscope combines three laser interferometer heads to measure linear position, pitch and yaw in high performance XY stages.
Explore the technical specifications of our optical encoders, including their options and variants, via our technical documents. Our compliance certificates provide additional guarantees of Renishaw's commitment to quality.
Discover how optical encoders enable excellent motion control in a range of industries and applications. Explore real-life examples of products and processes that benefit from Renishaw's encoder technology and extensive expertise.
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