[{"data":1,"prerenderedAt":208},["ShallowReactive",2],{"method-faizullin2022lidarsync":3},{"method":4,"reference":45,"equipment":64,"figures":93,"results":134},{"id":5,"label":6,"shortName":7,"title":8,"year":9,"era":10,"cluster":11,"scope":12,"keyIdeaZh":13,"keyIdeaEn":14,"fulltextStatus":15,"publicationStatus":16,"recommendation":17,"constructionRelevance":18,"validationEnvironment":19,"strengths":21,"limitations":24,"sensors":28,"platform":31,"estimator":33,"association":34,"timeModel":34,"deskew":34,"loopClosure":34,"globalOptimization":35,"mapRepresentation":34,"prior":35,"outputGeometry":36,"compute":37,"codeUrl":38,"codeLicense":39,"relatedVersions":40},"faizullin2022lidarsync","Faizullin et al., 2022","LiDAR sync by GNSS-clock emulation","Open-Source LiDAR Time Synchronization System by Mimicking GNSS-clock",2022,"recent","C13","sensing_calibration_sync_preprocessing","本系統以 STM32F4 微控制器模擬 GNSS 時鐘（PPS 與 NMEA GPRMC 訊息）輸入 VLP-16 的硬體同步介面，無需實體 GNSS 接收器，並以中斷為 IMU（MPU-9150）資料打時間戳記。作者以約十分鐘、逾五十萬個 UDP 封包的時間戳週期標準差評估精密度：ROS 抵達時間戳 82.64 µs、LiDAR 內部時鐘 0.31 µs（但無法與其他感測器同步）、本系統 1.35 µs；約 10 µs 的同步準確度則是依感測器文件推估，作者明言實測準確度評估不在本文範圍。","Microcontroller-emulated GNSS clock feeds the LiDAR sync interface and timestamps IMU data, reaching microsecond-level synchronization.","full_text_reviewed","peer_reviewed_published","main_body","not_reported（自組量測設備的同步方案，推論可用於工地低成本系統）",[20],"controlled_experiment",[22,23],"Timestamp-period precision (SD) 1.35 us for the MCU scheme vs 82.64 us for ROS arrival-time stamping (Table I)","Synchronization accuracy of about 10 us estimated from sensor documentation, not measured (Sec. IV)",[25,26,27],"Accuracy statement is for their specific VLP-16 and MPU-9150 setup (Sec. IV)","Precision (1.35 us SD) is lower than the isolated internal LiDAR clock (0.31 us) because of MCU-to-LiDAR clock drift between PPS pulses (Sec. IV, Table I)","Synchronization accuracy was not measured empirically; the about 10 us figure is derived from sensor documentation (Sec. IV)",[29,30],"3D LiDAR (VLP-16)","IMU (MPU-9150)",[32],"4WD wheeled moving platform carrying the IMU, MCU board and laptop (Fig. 1b); the paper does not say whether the Table I recording was made while moving","not_applicable (hardware timestamping)","not_applicable","none","synchronized LiDAR and IMU timestamps","STM32F4DISCOVERY MCU platform using one general-purpose timer as real-time clock (resolution 1\u002F76.8 us, about 13 ns), PPS generator and NMEA trigger; firmware built with STM32CubeMX; LiDAR data go directly to a laptop or mini PC, IMU data via the MCU; ROS driver provided","https:\u002F\u002Fgithub.com\u002FMobileRoboticsSkoltech\u002Flidar-sync-mimics-gps","none found (no LICENSE file and no license statement in README; checked 2026-09-25)",[41],{"relation":42,"title":43,"doi_or_url":44},"preprint","Open-Source LiDAR Time Synchronization System by Mimicking GPS-clock (earlier arXiv title)","https:\u002F\u002Farxiv.org\u002Fabs\u002F2107.02625",{"id":5,"kind":46,"shortName":7,"title":8,"authors":47,"year":9,"venue":51,"venueType":52,"publisher":53,"volumeIssuePages":54,"doi":55,"arxivId":56,"url":44,"firstPublicDate":57,"publicationStatus":16,"metadataStatus":58,"fulltextStatus":15,"era":10,"classicReason":34,"codeUrl":38,"cluster":11,"topics":59,"mdpi":60,"verification":61,"label":6,"fulltextRoute":62,"versionRead":63,"addedByCensus":60},"method",[48,49,50],"Marsel Faizullin","Anastasiia Kornilova","Gonzalo Ferrer","2022 IEEE International Symposium on Precision Clock Synchronization for Measurement, Control, and Communication (ISPCS)","conference","IEEE","pp. 1-5","10.1109\u002Fispcs55791.2022.9918446","2107.02625","2021-07-06","metadata_verified",[11],false,"corrected","NTU institutional (curl)","IEEE ISPCS 2022 version of record, pp. 1-5 (via NTU IEEE Xplore), compared word by word with arXiv 2107.02625v3 (13 Sep 2022); texts match except that the VoR drops a second mirror GitHub link and adds IEEE front matter",[65,72,77,82,88],{"category":66,"model":67,"canonical":67,"role":68,"dataset":69,"specs":70,"locator":71},"lidar","Velodyne VLP-16","method input",null,"hardware GNSS sync interface (PPS plus NMEA GPRMC); true packet period 1.328 ms and 1 us timestamp resolution per documentation; default 10 rotations per second","Sec. II, Sec. IV, Fig. 5",{"category":73,"model":74,"canonical":74,"role":68,"dataset":69,"specs":75,"locator":76},"imu","MPU-9150","1 kHz sample rate stabilized by an external quartz reference clock from the MCU; data-ready interrupt used for timestamping; interrupt delay documented with 10 us precision","Sec. II, Sec. IV",{"category":78,"model":79,"canonical":79,"role":68,"dataset":69,"specs":80,"locator":81},"other","STM32F4DISCOVERY","MCU platform emulating a GNSS receiver; timer RTC resolution 1\u002F76.8 us (about 13 ns); generates PPS and NMEA GPRMC messages and timestamps IMU samples","Sec. II, Sec. III",{"category":83,"model":84,"canonical":84,"role":85,"dataset":69,"specs":86,"locator":87},"compute","laptop or mini PC (model not reported)","compute for runtime","receives LiDAR packets and MCU-timestamped IMU data; ROS driver","Sec. II, Fig. 1",{"category":89,"model":90,"canonical":90,"role":68,"dataset":69,"specs":91,"locator":92},"platform","4WD moving platform (model not reported)","carries IMU, MCU board, laptop and other equipment inside its body","Fig. 1(b)",[94,107,116,125],{"refId":5,"refLabel":6,"fig":95,"whatZh":96,"license":97,"licenseUrl":98,"sourceUrl":99,"src":100,"width":101,"height":102,"thumb":103,"thumbWidth":104,"thumbHeight":105,"modified":106},"Fig. 1(a)","系統方塊圖：MCU 模擬 GNSS 時鐘送 PPS 與 NMEA 至 LiDAR，並以中斷為 IMU 打時間戳","CC BY-SA 4.0 (arXiv v3); version of record © 2022 IEEE","https:\u002F\u002Fcreativecommons.org\u002Flicenses\u002Fby-sa\u002F4.0\u002F","https:\u002F\u002Farxiv.org\u002Fhtml\u002F2107.02625v3\u002Fimages\u002Fblock_scheme.png","\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-1-a.webp",1002,462,"\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-1-a.thumb.webp",480,221,"converted to WebP",{"refId":5,"refLabel":6,"fig":92,"whatZh":108,"license":97,"licenseUrl":98,"sourceUrl":109,"src":110,"width":111,"height":112,"thumb":113,"thumbWidth":104,"thumbHeight":114,"modified":115},"搭載同步系統與 VLP-16 的四輪驅動移動平台外觀","https:\u002F\u002Farxiv.org\u002Fhtml\u002F2107.02625v3\u002Fimages\u002Fcommon_view_.jpg","\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-1-b.webp",1400,1133,"\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-1-b.thumb.webp",388,"resized to at most 1400 px wide and converted to WebP",{"refId":5,"refLabel":6,"fig":117,"whatZh":118,"license":97,"licenseUrl":98,"sourceUrl":119,"src":120,"width":121,"height":122,"thumb":123,"thumbWidth":104,"thumbHeight":124,"modified":106},"Fig. 4","計時器計數值與 PPS 訊號及 NMEA 訊息的時序關係圖","https:\u002F\u002Farxiv.org\u002Fhtml\u002F2107.02625v3\u002Fimages\u002Ftc_pps_ngm2.png","\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-4.webp",722,272,"\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-4.thumb.webp",181,{"refId":5,"refLabel":6,"fig":126,"whatZh":127,"license":97,"licenseUrl":98,"sourceUrl":128,"src":129,"width":130,"height":131,"thumb":132,"thumbWidth":104,"thumbHeight":133,"modified":106},"Fig. 5","純 ROS 時間戳所得封包週期的分布直方圖與真實週期","https:\u002F\u002Farxiv.org\u002Fhtml\u002F2107.02625v3\u002Fimages\u002Fno_gps.png","\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-5.webp",961,530,"\u002Ffigure-files\u002Ffaizullin2022lidarsync\u002Ffig-5.thumb.webp",265,{"totalRows":135,"groupCount":136,"groups":137,"others":207},4,2,[138,185],{"slug":139,"group":140,"sourceId":5,"sourceLabel":6,"table":141,"selfRows":142,"metrics":143,"seqs":154,"entrants":157,"cells":163,"outcomes":178,"locators":180,"hardware":181,"wordings":182,"notes":183},"faizullin2022lidarsync-table-i","faizullin2022lidarsync:Table I","Table I",3,[144,148,151],{"label":145,"unit":146,"statistic":147,"alignment":35},"STD of timestamp period","us","std",{"label":149,"unit":146,"statistic":150,"alignment":35},"minimum period","not_reported",{"label":152,"unit":146,"statistic":153,"alignment":35},"maximum period","max",[155],{"dataset":156,"sequence":150,"environment":150},"authors' recording",[158,160],{"name":159,"methodId":69,"linkable":60,"proposed":60,"self":60},"internal LiDAR clock (authors' driver patch)",{"name":161,"methodId":5,"linkable":162,"proposed":162,"self":162},"MCU-based clock (ours)",true,[164,168,171,173,175,176],[165,165,165,166,165,165,167,167,165],0,0.31,-1,[165,169,165,170,167,165,167,167,165],1,1327,[165,136,165,172,167,165,167,167,165],1328,[169,165,165,174,167,165,167,167,165],1.35,[169,169,165,170,167,165,167,167,165],[169,136,165,177,167,165,167,167,165],1365,[179],"no time sync with other sensors",[141],[],[],[184],"Packet-to-packet period of VLP-16 timestamps under three timestamping techniques; the text states about 10 min and more than half a million UDP packets only for the ROS timestamps (recording length for the other two techniques not stated); true period 1.328 ms per documentation; STD used as precision",{"slug":186,"group":187,"sourceId":5,"sourceLabel":6,"table":188,"selfRows":169,"metrics":189,"seqs":192,"entrants":194,"cells":196,"outcomes":199,"locators":201,"hardware":203,"wordings":204,"notes":205},"faizullin2022lidarsync-text-sec-iv","faizullin2022lidarsync:Text Sec. IV","Text Sec. IV",[190],{"label":191,"unit":146,"statistic":150,"alignment":35},"time synchronization accuracy",[193],{"dataset":34,"sequence":34,"environment":34},[195],{"name":161,"methodId":5,"linkable":162,"proposed":162,"self":162},[197],[165,165,165,198,165,165,167,167,165],10,[200],"documentation-based estimate, not measured; about 1 us order stated for two or more LiDARs of the same type",[202],"Sec. IV",[],[],[206],"Synchronization accuracy estimated from LiDAR and IMU documentation and MCU delays; not measured",[],1790510661577]