Method & Means for Ultra-High Sensitive, Absolute, Linear & Rotary Encoding (GSC-13703)

Abstract:
Optical encoders measure the linear or angular position of an object by optically detecting marks on a scale affixed to the object. Incremental encoders simply detect the relative motion of the object, not its absolute position. Although absolute linear optical encoders are available, they do not offer very high resolution (i.e., sensitivity). Furthermore, with conventional absolute linear encoders, the moving object is limited to 4 millimeters of travel at the highest practical resolution. Finally, if the scale on the object is damaged, most optical encoders yield 'dead spots,' no longer providing complete and accurate information. Researchers at NASA Goddard Space Flight Center have developed new absolute and incremental linear and rotary optical encoders that address many of the limitations of current encoder technology. Goddard's linear encoder uses a microlithographically patterned scale and a charge coupled device (CCD) array. A light source projects the scale's pattern onto the CCD array, and the image information is digitized and analyzed by an image processor. Pattern recognition algorithms are used to determine the relative and absolute position of the object. Potential applications include: aerospace and aviation; computer-aided machining; inspection equipment; linear positioning mechanisms; machine tools and robotics; medical imaging; profilometers and other instruments; semiconductor manufacturing; and surveying and telescopes.

Type of Offer: Licensing



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