{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T18:06:27Z","timestamp":1774029987231,"version":"3.50.1"},"reference-count":33,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,4,16]],"date-time":"2020-04-16T00:00:00Z","timestamp":1586995200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61905129, 51835007"],"award-info":[{"award-number":["61905129, 51835007"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Shenzhen Fundamental Research Funding","award":["JCYJ20170817160808432, JCYJ20180508152013054"],"award-info":[{"award-number":["JCYJ20170817160808432, JCYJ20180508152013054"]}]},{"DOI":"10.13039\/501100003453","name":"Natural Science Foundation of Guangdong Province","doi-asserted-by":"publisher","award":["2018A030313748"],"award-info":[{"award-number":["2018A030313748"]}],"id":[{"id":"10.13039\/501100003453","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Youth Funding of Shenzhen Graduate of Tsinghua University","award":["QN20180003"],"award-info":[{"award-number":["QN20180003"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Among various nanometer-level displacement measurement methods, grating interferometry-based linear encoders are widely used due to their high robustness, relatively low cost, and compactness. One trend of grating encoders is multi-axis measurement capability for simultaneous precision positioning and small order error motion measurement. However, due to both lack of suitable hardware data processing platform and of a real-time displacement calculation system, meeting the requirements of real-time data processing while maintaining the nanometer order resolutions on all these axes is a challenge. To solve above-mentioned problem, in this paper we introduce a design and experimental validation of a field programmable gate array (FPGA)-cored real-time data processing platform for grating encoders. This platform includes the following functions. First, a front-end photodetector and I\/V conversion analog circuit are used to realize basic analog signal filtering, while an eight-channel parallel, 16-bit precision, 200 kSPS maximum acquisition rate Analog-to-digital (ADC) is used to obtain digital signals that are easy to process. Then, an FPGA-based digital signal processing platform is implemented, which can calculate the displacement values corresponding to the phase subdivision signals in parallel and in real time at high speed. Finally, the displacement result is transferred by USB2.0 to the PC in real time through an Universal Asynchronous Receiver\/Transmitter (UART) serial port to form a complete real-time displacement calculation system. The experimental results show that the system achieves real-time data processing and displacement result display while meeting the high accuracy of traditional offline data solution methods, which demonstrates the industrial potential and practicality of our absolute two-dimensional grating scale displacement measurement system.<\/jats:p>","DOI":"10.3390\/s20082266","type":"journal-article","created":{"date-parts":[[2020,4,16]],"date-time":"2020-04-16T13:01:39Z","timestamp":1587042099000},"page":"2266","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["An FPGA Platform for Next-Generation Grating Encoders"],"prefix":"10.3390","volume":"20","author":[{"given":"Yaodong","family":"Han","sequence":"first","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kai","family":"Ni","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xinghui","family":"Li","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guanhao","family":"Wu","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"},{"name":"Department of Precision Instrument, Tsinghua University, Haidian District, Beijing 100084, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kangning","family":"Yu","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qian","family":"Zhou","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaohao","family":"Wang","sequence":"additional","affiliation":[{"name":"Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1016\/j.cirp.2015.05.009","article-title":"Measurement technologies for precision positioning","volume":"64","author":"Gao","year":"2015","journal-title":"CIRP Ann."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1631\/FITEE.1800708","article-title":"Displacement measuring grating interferometer: A review","volume":"20","author":"Hu","year":"2019","journal-title":"Front. Inf. Technol. Electron. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Shimizu, Y., Matsukuma, H., and Gao, W. (2019). Optical Sensors for Multi-Axis Angle and Displacement Measurement Using Grating Reflectors. Sensors-Basel, 19.","DOI":"10.3390\/s19235289"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"117","DOI":"10.2493\/jjspe.78.117","article-title":"Development and applications of Sumitomo precision stage technologies for FPD process","volume":"78","author":"Tomita","year":"2012","journal-title":"J. Jpn. Soc. Precis. Eng."},{"key":"ref_5","unstructured":"(2020, April 10). Groundbreaking Absolute Linear Encoder and Rotary (Angle) Encoder is BiSS\u00ae Protocol Compatible. Available online: https:\/\/www.renishaw.com.cn\/zh\/11110.aspx."},{"key":"ref_6","unstructured":"(2020, April 10). Linear Encoder Products\u2014Sealed and Enclosed\u2014HEIDENHAIN. Available online: https:\/\/www.heidenhain.us\/product\/linear-encoders-for-length-measurement\/."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"93","DOI":"10.5875\/ausmt.v1i2.53","article-title":"A planar laser diffraction encoder in Littrow configuration for 2D nanometric positioning","volume":"1","author":"Fan","year":"2011","journal-title":"Int. J. Autom. Smart Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"771","DOI":"10.1016\/j.precisioneng.2013.03.005","article-title":"A six-degree-of-freedom surface encoder for precision positioning of a planar motion stage","volume":"37","author":"Li","year":"2013","journal-title":"Precis. Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"576","DOI":"10.1016\/j.precisioneng.2012.04.005","article-title":"A sub-nanometric three-axis surface encoder with short-period planar gratings for stage motion measurement","volume":"36","author":"Kimura","year":"2012","journal-title":"Precis. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1016\/j.cirp.2011.03.052","article-title":"A three-axis autocollimator for detection of angular error motions of a precision stage","volume":"60","author":"Gao","year":"2011","journal-title":"CIRP Ann."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1016\/j.cirp.2007.05.126","article-title":"A three-axis displacement sensor with nanometric resolution","volume":"56","author":"Gao","year":"2007","journal-title":"CIRP Ann."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"105901","DOI":"10.1088\/0957-0233\/22\/10\/105901","article-title":"Design and construction of a single unit multi-function optical encoder for a six-degree-of-freedom motion error measurement in an ultraprecision linear stage","volume":"22","author":"Lee","year":"2011","journal-title":"Meas. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1833","DOI":"10.1143\/JJAP.47.1833","article-title":"Diffractive laser encoder with a grating in Littrow configuration","volume":"47","author":"Kao","year":"2008","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"23603","DOI":"10.1117\/1.1839227","article-title":"Double-diffraction planar encoder by conjugate optics","volume":"44","author":"Kao","year":"2005","journal-title":"Opt. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2767","DOI":"10.1364\/AO.48.002767","article-title":"Five-degrees-of-freedom diffractive laser encoder","volume":"48","author":"Liu","year":"2009","journal-title":"Appl. Opt."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"189","DOI":"10.3788\/co.20201301.0189","article-title":"Grating-based precision measurement system for five-dimensional measurement","volume":"13","author":"Lv","year":"2020","journal-title":"Chin. Opt."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1117\/1.1523943","article-title":"High-performance absolute rotary encoder using multitrack and M-code","volume":"42","author":"Matsuzoe","year":"2003","journal-title":"Opt. Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"24483","DOI":"10.3390\/s141224483","article-title":"An architecture for measuring joint angles using a long period fiber grating-based sensor","volume":"14","year":"2014","journal-title":"Sensors"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1016\/j.aeue.2008.06.011","article-title":"Hardware implementation of a pulse mode neural network-based edge detection system","volume":"63","author":"Krid","year":"2009","journal-title":"AEU-Int. J. Electron. Commun."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"B736","DOI":"10.1364\/OE.19.00B736","article-title":"Experimental demonstration of flexible bandwidth networking with real-time impairment awareness","volume":"19","author":"Geisler","year":"2011","journal-title":"Opt. Express"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Ni, K., Wang, H., Li, X., Wang, X., Xiao, X., and Zhou, Q. (2016, January 12\u201314). Measurement uncertainty evaluation of the three degree of freedom surface encoder. Proceedings of the Optical Metrology and Inspection for Industrial Applications IV, Beijing, China.","DOI":"10.1117\/12.2246243"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"8804","DOI":"10.1364\/OE.20.008804","article-title":"Real-time FPGA data collection of pulsed-laser cavity ringdown signals","volume":"20","author":"Spence","year":"2012","journal-title":"Opt. Express"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"207","DOI":"10.4028\/www.scientific.net\/SSP.180.207","article-title":"FPGA-ARM heterogeneous system for high speed signal analysis","volume":"180","author":"Jamro","year":"2012","journal-title":"Solid State Phenom."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7985","DOI":"10.1364\/OE.17.007985","article-title":"Real-time reception of multi-gigabit coherent optical OFDM signals","volume":"17","author":"Yang","year":"2009","journal-title":"Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Cosijns, S.J.A.G., and Jansen, M.J. (2014). 9-Advanced optical incremental sensors: Encoders and interferometers. Smart Sensors and MEMs, Woodhead Publishing.","DOI":"10.1533\/9780857099297.1.230"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1775","DOI":"10.3390\/s18061775","article-title":"Development of A Low-Cost FPGA-Based Measurement System for Real-Time Processing of Acoustic Emission Data: Proof of Concept Using Control of Pulsed Laser Ablation in Liquids","volume":"18","author":"Sebastian","year":"2018","journal-title":"Sensors-Basel"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1007\/s10854-007-9491-2","article-title":"Real time surface morphology analysis of semiconductor materials and devices using 4D interference microscopy","volume":"19","author":"Montgomery","year":"2008","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"7710","DOI":"10.3390\/s110807710","article-title":"FPGA-based smart sensor for online displacement measurements using a heterodyne interferometer","volume":"11","author":"Serroukh","year":"2011","journal-title":"Sensors"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Zhang, H., Ljusic, Z., Hovey, G., Veran, J., Herriot, G., and Dumas, M. (2012, January 1\u20136). A high-performance FPGA platform for adaptive optics real-time control. Proceedings of the Adaptive Optics Systems III, Amsterdam, The Netherlands.","DOI":"10.1117\/12.925479"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1704","DOI":"10.1109\/JPROC.2005.853538","article-title":"Optical and interferometric lithography-nanotechnology enablers","volume":"93","author":"Brueck","year":"2005","journal-title":"Proc. IEEE"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Fu, M., Li, C., Zhu, G., Shi, H., and Chen, F. (2020). A High Precision Time Grating Displacement Sensor Based on Temporal and Spatial Modulation of Light-Field. Sensors, 20.","DOI":"10.3390\/s20030921"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Girschikofsky, M., Ryvlin, D., Waldvogel, S., and Hellmann, R. (2019). Optical Sensor for Real-Time Detection of Trichlorofluoromethane. Sensors, 19.","DOI":"10.3390\/s19030632"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Kim, J.S., Kim, B.K., Jang, M., Kang, K., Kim, D.E., Ju, B., and Kim, J. (2020). Wearable Hand Module and Real-Time Tracking Algorithms for Measuring Finger Joint Angles of Different Hand Sizes with High Accuracy Using FBG Strain Sensor. Sensors, 20.","DOI":"10.3390\/s20071921"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/8\/2266\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T13:30:54Z","timestamp":1760362254000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/8\/2266"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,16]]},"references-count":33,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2020,4]]}},"alternative-id":["s20082266"],"URL":"https:\/\/doi.org\/10.3390\/s20082266","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,16]]}}}