المؤلفون: Noh, DongKi, Lim, Hyungtae, Eoh, Gyuho, Choi, Duckyu, Choi, Jeongsik, Lim, Hyunjun, Baek, SeungMin, Myung, Hyun

المصدر: IEEE Robotics and Automation Letters, 2024

مصطلحات موضوعية: Computer Science - Robotics

الوصف: In commercial autonomous service robots with several form factors, simultaneous localization and mapping (SLAM) is an essential technology for providing proper services such as cleaning and guidance. Such robots require SLAM algorithms suitable for specific applications and environments. Hence, several SLAM frameworks have been proposed to address various requirements in the past decade. However, we have encountered challenges in implementing recent innovative frameworks when handling service robots with low-end processors and insufficient sensor data, such as low-resolution 2D LiDAR sensors. Specifically, regarding commercial robots, consistent performance in different hardware configurations and environments is more crucial than the performance dedicated to specific sensors or environments. Therefore, we propose a) a multi-stage %hierarchical approach for global pose estimation in embedded systems; b) a graph generation method with zero constraints for synchronized sensors; and c) a robust and memory-efficient method for long-term pose-graph optimization. As verified in in-home and large-scale indoor environments, the proposed method yields consistent global pose estimation for services in commercial fields. Furthermore, the proposed method exhibits potential commercial viability considering the consistent performance verified via mass production and long-term (> 5 years) operation.

الوصول الحر: http://arxiv.org/abs/2406.19634Test

المؤلفون: Song, Jiho, Hyun, Seong-Hwan, Lee, Jong-Ho, Choi, Jeongsik, Kim, Seong-Cheol

مصطلحات موضوعية: Computer Science - Information Theory

الوصف: We develop joint vehicle tracking and road side unit (RSU) selection algorithms suitable for vehicle-to-infrastructure (V2I) communications. We first design an analytical framework for evaluating vehicle tracking systems based on the extended Kalman filter. A simple, yet effective, metric that quantifies the vehicle tracking performance is derived in terms of the angular derivative of a dominant spatial frequency. Second, an RSU selection algorithm is proposed to select a proper RSU that enhances the vehicle tracking performance. A joint vehicle tracking algorithm is also developed to maximize the tracking performance by considering sounding samples at multiple RSUs while minimizing the amount of sample exchange. The numerical results verify that the proposed vehicle tracking algorithms give better performance than conventional signal-to-noise ratio-based tracking systems.
Comment: 6 Pages, 5 figures, submitted manuscript for possible publication

الوصول الحر: http://arxiv.org/abs/2201.00138Test

المؤلفون: Choi, Jeongsik

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture, Electrical Engineering and Systems Science - Signal Processing

الوصف: The fine timing measurement (FTM) protocol is designed to determine precise ranging between Wi-Fi devices using round-trip time (RTT) measurements. However, the multipath propagation of radio waves generates inaccurate timing information, degrading the ranging performance. In this study, we use a neural network (NN) to adaptively learn the unique measurement patterns observed at different indoor environments and produce enhanced ranging outputs from raw FTM measurements. Moreover, the NN is trained based on an unsupervised learning framework, using the naturally accumulated sensor data acquired from users accessing location services. Therefore, the effort involved in collecting training data is significantly minimized. The experimental results verified that the collection of unlabeled data for a short duration is sufficient to learn the pattern in raw FTM measurements and produce improved ranging results. The proposed method reduced the ranging errors in raw distance measurements and well-calibrated ranging results requiring the collection of ground truth data by 47-50% and 17-29%, respectively. Consequently, positioning error reduced by 17-30% compared to the result with well-calibrated ranging.
Comment: 10 pages, 12 figures, submitted to IEEE Transactions on Vehicular Technology

الوصول الحر: http://arxiv.org/abs/2112.14138Test

المؤلفون: Choi, Jeongsik

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture, Electrical Engineering and Systems Science - Signal Processing

الوصف: Because each indoor site has its own radio propagation characteristics, a site survey process is essential to optimize a Wi-Fi ranging strategy for range-based positioning solutions. This paper studies an unsupervised learning technique that autonomously investigates the characteristics of the surrounding environment using sensor data accumulated while users use a positioning application. Using the collected sensor data, the device trajectory can be regenerated, and a Wi-Fi ranging module is trained to make the shape of the estimated trajectory using Wi-Fi similar to that obtained from sensors. In this process, the ranging module learns the way to identify the channel conditions from each Wi-Fi access point (AP) and produce ranging results accordingly. Furthermore, we collect the channel state information (CSI) from beacon frames and evaluate the benefit of using CSI in addition to received signal strength (RSS) measurements. When CSI is available, the ranging module can identify more diverse channel conditions from each AP, and thus more precise positioning results can be achieved. The effectiveness of the proposed learning technique is verified using a real-time positioning application implemented on a PC platform.
Comment: 13 pages, 16 figures, submitted to an IEEE journal for publication, demo video is available: https://youtu.be/-6vfLEBS9M8Test

الوصول الحر: http://arxiv.org/abs/2007.06204Test

المؤلفون: Choi, Jeongsik, Choi, Yang-Seok

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture, Electrical Engineering and Systems Science - Signal Processing

الوصف: As positioning solutions integrate multiple components to improve accuracy, the number of parameters that require calibration has increased. This paper studies a calibration-free positioning technique using Wi-Fi ranging and pedestrian dead reckoning (PDR), where every parameter in the system is optimized in real-time. This significantly decreases the time and effort required to perform manual calibration procedures and enables the positioning solution to achieve robust performance in various situations. Additionally, this paper studies an efficient way of performing irregular Wi-Fi ranging procedures to improve battery life and network performance of mobile devices. The positioning performance of the proposed method was verified using a real-time Android application on several mobile devices under a large indoor office environment. Without any calibration, the proposed method achieved up to 1.38 m average positioning accuracy for received signal strength (RSS)-based ranging scenarios, which differs only by 30 cm from the benchmark assuming perfect calibration. In addition, the proposed method achieved up to 1.04 m accuracy for round trip time (RTT)-based ranging scenarios with a 40 MHz bandwidth configuration, which differs only by 10 cm from the benchmark.
Comment: 14 pages, 16 figures, demo video is available: https://youtu.be/_FnznD1gxV0Test

الوصول الحر: http://arxiv.org/abs/2003.06013Test

المؤلفون: Choi, Jeongsik, Choi, Yang-Seok, Talwar, Shilpa

مصطلحات موضوعية: Computer Science - Networking and Internet Architecture

الوصف: Given that the accuracy of range-based positioning techniques generally increases with the number of available anchor nodes, it is important to secure more of these nodes. To this end, this paper studies an unsupervised learning technique to obtain the coordinates of unknown nodes that coexist with anchor nodes. As users use the location services in an area of interests, the proposed method automatically discovers unknown nodes and estimates their coordinates. In addition, this method learns an appropriate calibration curve to correct the distortion of raw distance measurements. As such, the positioning accuracy can be greatly improved using more anchor nodes and well-calibrated distance measurements. The performance of the proposed method was verified using commercial Wi-Fi devices in a practical indoor environment. The experiment results show that the coordinates of unknown nodes and the calibration curve are simultaneously determined without any ground truth data.
Comment: 6 pages, 8 figures, accepted at the 10th international conference on indoor positioning and indoor navigation (IPIN) 2019

الوصول الحر: http://arxiv.org/abs/1907.09514Test

المؤلفون: Lim, Sohee, Jung, Jaehoon, Lee, Eunji, Choi, Jeongsik, Kim, Seong-Cheol

المساهمون: Technology Innovation Program, Ministry of Trade, Industry and Energy (MOTIE), South Korea

المصدر: IEEE Internet of Things Journal ; volume 11, issue 4, page 7002-7012 ; ISSN 2327-4662 2372-2541

مصطلحات موضوعية: Computer Networks and Communications, Computer Science Applications, Hardware and Architecture, Information Systems, Signal Processing

الإتاحة: https://doi.org/10.1109/jiot.2023.3313357Test
http://xplorestaging.ieee.org/ielx7/6488907/10419857/10243616.pdf?arnumber=10243616Test

المؤلفون: Lee, Eunji, Park, Kyoung-Min, Lee, Byeong-Ho, Kim, Seong-Cheol, Choi, Jeongsik

المساهمون: Ministry of Science and ICT, South Korea, National Research Foundation of Korea

المصدر: IEEE Sensors Journal ; volume 24, issue 1, page 1042-1050 ; ISSN 1530-437X 1558-1748 2379-9153

مصطلحات موضوعية: Electrical and Electronic Engineering, Instrumentation

الإتاحة: https://doi.org/10.1109/jsen.2023.3333331Test
http://xplorestaging.ieee.org/ielx7/7361/10378722/10325431.pdf?arnumber=10325431Test

المؤلفون: Potortì, Francesco, Park, Sangjoon, Crivello, Antonino, Palumbo, Filippo, GIROLAMI, MICHELE, Barsocchi, Paolo, Lee, Soyeon, Torres-Sospedra, Joaquín, Jimenez Ruiz, Antonio Ramon, Perez-Navarro, Antoni, Mendoza-Silva, Germán Martín, Seco, Fernando, ortiz, miguel, PERUL, Johan, Renaudin, Valerie, Kang, Hyunwoong, Park, Soyoung, Lee, Jae Hong, Park, Chan Gook, Ha, Jisu, Han, JaeSeung, Park, Changjun, Kim, Keunhye, Lee, Yonghyun, Gye, Seunghun, lee, keumryeol, Kim, Eunjee, Choi, Jeongsik, choi, Yang-Seok, Talwar, Shilpa, Cho, Seong Yun, Ben-Moshe, Boaz, Scherbakov, Alex, Antsfeld, Leonid, Sansano-Sansano, Emilio, Chidlovskii, Boris, Kronenwett, Nikolai, Prophet, Silvia, Landay, Yael, Marbel, Revital, Zheng, Lingxiang, Peng, Ao, Lin, Zhichao, Wu, Bang, Ma, Chengqi, Poslad, Stefan, Selviah, David, Wu, Wei, Ma, Zixiang, Zhang, Wenchao, Wei, Dongyan, Yuan, Hong, Jiang, Jun-Bang, Huang, Shao-Yung, Liu, Jing-Wen, Su, Kuan-Wu, Leu, Jenq-Shiou, Nishiguchi, Kazuki, BOUSSELHAM, Walid, Uchiyama, Hideaki, Thomas, Diego, Shimada, Atsushi, Taniguchi, Rin-ichiro, Cortés Puschel, Vicente, Lungenstrass, Tomás, Ashraf, Imran, Lee, Chanseok, Ali, Muhammad Usman, Im, Yeongjun, Kim, Gunzung, Eom, Jeongsook, Hur, Soojung, Park, Yongwan, Opiela, Miroslav, Moreira, Adriano, Nicolau, Maria João, Pendão, Cristiano, Silva, Ivo, Meneses, Filipe, Costa, António, Trogh, Jens, Plets, David, Chien, Ying-Ren, Chang, Tzu-Yu, Fang, Shih-Hau, Tsao, Yu

مصطلحات موضوعية: indoor localisation, indoor navigation, competition, benchmarking, smartphone-based positioning, foot-mounted pedestrian dead reckoning, Wi-Fi fingerprinting, magnetic field, camera-based positioning, inertial-based positioning, sensor fusion, Kalman filter, particle filter, stakeholders, atmospheric measurements, particle measurements, real-time systems, wireless fidelity, sensor systems

الوصف: IPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m 2 outdoors and and 6000 m 2 indoors over three floors, with a total path length exceeding 500 m. IPIN competitions, based on the EvAAL framework, have aimed at comparing the accuracy performance of personal positioning systems in fair and realistic conditions: past editions of the competition were carried in big conference settings, university campuses and a shopping mall. Positioning accuracy is computed while the person carrying the system under test walks at normal walking speed, uses lifts and goes up and down stairs or briefly stops at given points. Results presented here are a showcase of state-of-the-art systems tested side by side in real-world settings as part of the on-site real-time competition Tracks. Results for off-site Tracks allow a detailed and reproducible comparison of the most recent positioning and tracking algorithms in the same environment as the on-site Tracks.

وصف الملف: application/pdf

العلاقة: Development of human enhancement fire helmet and fire suppression support system; Basic Science Research Program; ICT Research and Development Program of MSIP/IITP (Development of Precise Positioning Technology for the Enhancement of Pedestrian Position/Spatial Cognition and Sports Competition Analysis); MICROCEBUS; REPNIN PLUS; TECHNOFUSION(III)CM; Development of wireless communication tracking-based location information system in disaster scene for fire-fighters and person who requested rescue; Strategic Priority Research Program; IEEE Access, Vol. 8 (2020); F. Potortì et al., "The IPIN 2019 Indoor Localisation Competition—Description and Results," in IEEE Access, vol. 8, pp. 206674-206718, 2020, doi:10.1109/ACCESS.2020.3037221.; http://hdl.handle.net/10234/200929Test

الإتاحة: https://doi.org/10.1109/ACCESS.2020.3037221Test
http://hdl.handle.net/10234/200929Test

المؤلفون: Choi, Jeongsik, Choi, Yang-Seok, Talwar, Shilpa

المصدر: Machine Learning for Indoor Localization and Navigation ; page 101-130 ; ISBN 9783031267116 9783031267123

الإتاحة: https://doi.org/10.1007/978-3-031-26712-3_5Test