Articles de revues : « Outdoors positioning »

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Nguyen, Ba Dat, Hoang Long Nguyen, Quoc Hung Nguyen, Quoc Tuan Le, Ha Tran, Van Dua Nguyen et Si Hong Hoang. « Designing an outdoor machinery monitoring device with integrated real-time kinematic positioning ». Ministry of Science and Technology, Vietnam 64 (12 octobre 2022) : 28–32. http://dx.doi.org/10.31276/vjst.64(10db).28-32.

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Accurate positioning ofoutdoor vehicles and machinery is of the top importance inmanagement, tracking, analysis, and control applications. However, most of the current vehicle tracking devices have an error of a few meters to several tens of meters,which is not enough for applications requiring high accuracy. This paper presents the design of an outdoor machinery monitoring device that integrates precise positioning technology of real-time kinematic (RTK). The device uses U-Blox’s Zed F9P module as the core to perform the high accuracy positioning function. Thanks to the integration of RTK positioning technology, the device can monitor the location of machinery outdoors with centimeter-level accuracy.

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Li, Ningbo, Lianwu Guan, Yanbin Gao, Zhejun Liu, Ye Wang et Hanxiao Rong. « A Low Cost Civil Vehicular Seamless Navigation Technology Based on Enhanced RISS/GPS between the Outdoors and an Underground Garage ». Electronics 9, n^o 1 (8 janvier 2020) : 120. http://dx.doi.org/10.3390/electronics9010120.

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Vehicles have to rely on satellite navigation in an open environment. However, satellite navigation cannot obtain accurate positioning information for vehicles in the interior of underground parking lots, as they comprise a semi-enclosed navigation space. Therefore, vehicular navigation needs to take into consideration both outdoor and indoor environments. Actually, outdoor navigation and indoor navigation require different positioning methods, and it is of great importance to choose a reasonable navigation and positioning algorithm solution for vehicles. Fortunately, the integrated navigation of the Global Positioning System (GPS) and the Micro-Electro-Mechanical System (MEMS) inertial navigation system could solve the problem of switching navigation algorithms in the entrance and exit of underground parking lots. This paper proposes a low cost vehicular seamless navigation technology based on the reduced inertial sensor system (RISS)/GPS between the outdoors and an underground garage. Specifically, the enhanced RISS is a positioning algorithm based on three inertial sensors and one odometer, which could achieve a similar location effect as the full model integrated navigation, reduce the costs greatly, and improve the efficiency of each sensor.

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Wang, Changqiang, Aigong Xu, Xin Sui, Yushi Hao, Zhengxu Shi et Zhijian Chen. « A Seamless Navigation System and Applications for Autonomous Vehicles Using a Tightly Coupled GNSS/UWB/INS/Map Integration Scheme ». Remote Sensing 14, n^o 1 (22 décembre 2021) : 27. http://dx.doi.org/10.3390/rs14010027.

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Seamless positioning systems for complex environments have been a popular focus of research on positioning safety for autonomous vehicles (AVs). In particular, the seamless high-precision positioning of AVs indoors and outdoors still poses considerable challenges and requires continuous, reliable, and high-precision positioning information to guarantee the safety of driving. To obtain effective positioning information, multiconstellation global navigation satellite system (multi-GNSS) real-time kinematics (RTK) and an inertial navigation system (INS) have been widely integrated into AVs. However, integrated multi-GNSS and INS applications cannot provide effective and seamless positioning results for AVs in indoor and outdoor environments due to limited satellite availability, multipath effects, frequent signal blockages, and the lack of GNSS signals indoors. In this contribution, multi-GNSS-tightly coupled (TC) RTK/INS technology is developed to solve the positioning problem for a challenging urban outdoor environment. In addition, ultrawideband (UWB)/INS technology is developed to provide accurate and continuous positioning results in indoor environments, and INS and map information are used to identify and eliminate UWB non-line-of-sight (NLOS) errors. Finally, an improved adaptive robust extended Kalman filter (AREKF) algorithm based on a TC integrated single-frequency multi-GNSS-TC RTK/UWB/INS/map system is studied to provide continuous, reliable, high-precision positioning information to AVs in indoor and outdoor environments. Experimental results show that the proposed scheme is capable of seamlessly guaranteeing the positioning accuracy of AVs in complex indoor and outdoor environments involving many measurement outliers and environmental interference effects.

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Mogyorósi, Ferenc, Péter Revisnyei, Azra Pašić, Zsófia Papp, István Törös, Pál Varga et Alija Pašić. « Positioning in 5G and 6G Networks—A Survey ». Sensors 22, n^o 13 (23 juin 2022) : 4757. http://dx.doi.org/10.3390/s22134757.

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Determining the position of ourselves or our assets has always been important to humans. Technology has helped us, from sextants to outdoor global positioning systems, but real-time indoor positioning has been a challenge. Among the various solutions, network-based positioning became an option with the arrival of 5G mobile networks. The new radio technologies, minimized end-to-end latency, specialized control protocols, and booming computation capacities at the network edge offered the opportunity to leverage the overall capabilities of the 5G network for positioning—indoors and outdoors. This paper provides an overview of network-based positioning, from the basics to advanced, state-of-the-art machine-learning-supported solutions. One of the main contributions is the detailed comparison of machine learning techniques used for network-based positioning. Since new requirements are already in place for 6G networks, our paper makes a leap towards positioning with 6G networks. In order to also highlight the practical side of the topic, application examples from different domains are presented with a special focus on industrial and vehicular scenarios.

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Zou, Deyue, Shutong Niu, Shuhao Chen, Binhong Su, Xinyi Cheng, Jie Liu, Yunfeng Liu et Yang Li. « A smart city used low-latency seamless positioning system based on inverse global navigation satellite system technology ». International Journal of Distributed Sensor Networks 15, n^o 9 (septembre 2019) : 155014771987381. http://dx.doi.org/10.1177/1550147719873815.

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People have to move between indoor and outdoor frequently in city scenarios. The global navigation satellite system signal cannot provide reliable indoor positioning services. To solve the problem, this article proposes a seamless positioning system based on an inverse global navigation satellite system signal, which can extend the global navigation satellite system service into the indoor scenario. In this method, a signal source is arranged at a key position in the room, and the inverse global navigation satellite system signal is transmitted to the global navigation satellite system receiver to obtain a preset positioning result. The indoor positioning service is continued with the inertial navigation system after leaving the key position. The inverse global navigation satellite system seamless positioning system proposed in this article can unify indoor and outdoor positioning using the same receiver. The receiver does not need to re-receive navigation information when the scene changes, which avoids the switching process. Through the design of signal layer coverage, the receiver is in a warm start state, and the users can quickly fix the position when the scenario changes, realizing quick access in a true sense. This enables the ordinary commercial global navigation satellite system receiver to obtain indoor positioning capability without modification, and the algorithm can perform accurate positioning indoors and outdoors without switching.

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Chirantan Ganguly, Sagnik Nayak, S. Irene, Anil Kumar Gupta, Suresh V. et Pradeep Kumar CH. « Utilizing machine learning algorithms for localization using RSSI values of wireless LAN ». ITU Journal on Future and Evolving Technologies 3, n^o 2 (17 juin 2022) : 98–107. http://dx.doi.org/10.52953/mvre7314.

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With the development of new technologies, there has been an upsurge in the demand for precise localization in both outdoor and indoor environments. While a Global Positioning System (GPS) provides sufficient positioning precision in outdoor settings, its accuracy declines in indoor scenarios, necessitating the development of novel positioning approaches that function accurately both indoors and outdoors. The use of various Wireless Local Area Network (WLAN) parameters for localization has been conceptualized. In this study, we attempt to do localization using machine learning methods on WLAN Received Signal Strength Indicator (WLAN RSSI) measurements. We compare the performance of multiple machine learning algorithms on the data set to see which can be used to design efficient future localization systems. The proposed study has achieved second place for the problem statement "ITU-ML5G-PS-016: Location estimation using RSSI of wireless LAN" in AI/ML in 5G Challenge 2021 organized by the International Telecommunication Union.

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Li, Ningbo, Lianwu Guan, Yanbin Gao, Shitong Du, Menghao Wu, Xingxing Guang et Xiaodan Cong. « Indoor and Outdoor Low-Cost Seamless Integrated Navigation System Based on the Integration of INS/GNSS/LIDAR System ». Remote Sensing 12, n^o 19 (8 octobre 2020) : 3271. http://dx.doi.org/10.3390/rs12193271.

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Global Navigation Satellite System (GNSS) provides accurate positioning data for vehicular navigation in open outdoor environment. In an indoor environment, Light Detection and Ranging (LIDAR) Simultaneous Localization and Mapping (SLAM) establishes a two-dimensional map and provides positioning data. However, LIDAR can only provide relative positioning data and it cannot directly provide the latitude and longitude of the current position. As a consequence, GNSS/Inertial Navigation System (INS) integrated navigation could be employed in outdoors, while the indoors part makes use of INS/LIDAR integrated navigation and the corresponding switching navigation will make the indoor and outdoor positioning consistent. In addition, when the vehicle enters the garage, the GNSS signal will be blurred for a while and then disappeared. Ambiguous GNSS satellite signals will lead to the continuous distortion or overall drift of the positioning trajectory in the indoor condition. Therefore, an INS/LIDAR seamless integrated navigation algorithm and a switching algorithm based on vehicle navigation system are designed. According to the experimental data, the positioning accuracy of the INS/LIDAR navigation algorithm in the simulated environmental experiment is 50% higher than that of the Dead Reckoning (DR) algorithm. Besides, the switching algorithm developed based on the INS/LIDAR integrated navigation algorithm can achieve 80% success rate in navigation mode switching.

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Maghdid, Halgurd S., Ladeh Sardar Abdulrahman, Mohammed H. Ahmed et Azhin Tahir Sabir. « Modified WiFi-RSS Fingerprint Technique to locate Indoors-Smartphones : FENG building at Koya University as a case study ». Kurdistan Journal of Applied Research 2, n^o 3 (27 août 2017) : 212–17. http://dx.doi.org/10.24017/science.2017.3.41.

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Positioning system used for different purposes and different services, many researches are going on to find a more accurate position with low error within high performance. There are many localization solutions with different architectures, configurations, accuracies and reliabilities for both outdoors and indoors. For example, Global Navigation Satellite System (GNSS) technology has been used for outdoors. Global Positioning System (GPS) is one of the most common outdoors tracking solutions in the world, for outdoors, however, when indoors; it could not be accurately tracked users by using a GPS system. This is because, when users enters into indoors the GPS signals will no longer available due to blocked by the roof of buildings and it is no longer considered as a viable option. WiFi Positioning System (WPS) can be used as an alternative solution to define users’ position, especially when GPS signal is not available. Further, WPS is a low cost solution, because there is no need to deploying WiFi Access Points (WAPs) in the vicinity, as they are installed to access the Internet. In this paper, specifically, WiFi-RSS Fingerprinting technique is used to locate smartphones using WAPs signals with a modified calculation. The new modified calculation is to dynamic weighting of the WAPs RSS values based on the real-live indoors structure. The achieved positioning accuracy, based on several trial experiments, is up to 6 meters via the implemented algorithm in the MALTAB.

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Angelats, E., J. A. Navarro et E. Parés. « TOWARDS SEAMLESS INDOOR-OUTDOOR POSITIONING : THE IOPES PROJECT APPROACH ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B4-2020 (25 août 2020) : 313–19. http://dx.doi.org/10.5194/isprs-archives-xliii-b4-2020-313-2020.

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Abstract. The management of emergencies require the use of multiple resources that must be coordinated to achieve the best possible results. For a good decision-making process, the availability of timely and reliable information about the variables on which such process rely is crucial. Among these variables, the ability to track the position in the field - either outdoors or indoors - of the members of the emergency teams it is of special importance. The IOPES project targets at improving an existing, already operational emergency management system where the tracking of operative staff is integrated. This paper concentrates only in the positioning aspect of IOPES - which encompasses other subsystems, such as portable communications or fast mapping - and describes the approach adopted by the project to perform such integration. This includes the concept itself, the hardware selected and well as the algorithms used to implement a portable, lightweight positioning device able to provide seamless indoor / outdoor positioning that will make possible the real-time tracking of personnel in the field. Promising preliminary results for mixed indoor-outdoor trajectories are as well presented.

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Qamaz, Yousef, Angela Schwering et Janina Bistron. « Experimental evaluation of using BLE beacon for outdoor positioning in GPS-denied environment ». AGILE : GIScience Series 3 (10 juin 2022) : 1–9. http://dx.doi.org/10.5194/agile-giss-3-13-2022.

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Abstract. Although Global Positioning System (GPS) is widely used in outdoor location-based services, it still lacks precision due to obstacles that reduce its performance, such as near tall buildings, with bad weather conditions, and under tree canopies. In some situations, inaccurate localization or delay in getting location locks can adversely affect some location-based services’ functionality. Furthermore, it might make these services less efficient or even completely useless, especially when the receiver device has no SIM card or when the service requires a precision higher than three meters. As a solution to this issue, this study designs, develops, and evaluates a prototype location-based system that uses Bluetooth Low Energy beacons for short-range positioning in outdoor environments as a GPS alternative. The proposed system is a game that includes navigational tasks, which can be accomplished by reaching the proximity of two meters from the beacon’s location. The study involved conducting an experiment outdoors with a focus on areas where GPS signals are degraded to assess our proposed system’s efficiency and feasibility compared to the usage of GPS. The results proved BLE beacons’ ability to provide better positioning results than GPS, not only in terms of accuracy but also in terms of stability of positioning results over time. Based on the findings, the study outlines a set of guidelines to be considered in choosing a suitable positioning technology.

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Toth, C. K., Z. Koppanyi, V. Navratil et D. Grejner-Brzezinska. « GEOREFERENCING IN GNSS-CHALLENGED ENVIRONMENT : INTEGRATING UWB AND IMU TECHNOLOGIES ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-1/W1 (31 mai 2017) : 175–80. http://dx.doi.org/10.5194/isprs-archives-xlii-1-w1-175-2017.

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Acquiring geospatial data in GNSS compromised environments remains a problem in mapping and positioning in general. Urban canyons, heavily vegetated areas, indoor environments represent different levels of GNSS signal availability from weak to no signal reception. Even outdoors, with multiple GNSS systems, with an ever-increasing number of satellites, there are many situations with limited or no access to GNSS signals. Independent navigation sensors, such as IMU can provide high-data rate information but their initial accuracy degrades quickly, as the measurement data drift over time unless positioning fixes are provided from another source. At The Ohio State University’s Satellite Positioning and Inertial Navigation (SPIN) Laboratory, as one feasible solution, Ultra- Wideband (UWB) radio units are used to aid positioning and navigating in GNSS compromised environments, including indoor and outdoor scenarios. Here we report about experiences obtained with georeferencing a pushcart based sensor system under canopied areas. The positioning system is based on UWB and IMU sensor integration, and provides sensor platform orientation for an electromagnetic inference (EMI) sensor. Performance evaluation results are provided for various test scenarios, confirming acceptable results for applications where high accuracy is not required.

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Angelats, E., P. F. Espín-López, J. A. Navarro et M. E. Parés. « PERFORMANCE ANALYSIS OF THE IOPES SEAMLESS INDOOR-OUTDOOR POSITIONING APPROACH ». International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B4-2021 (30 juin 2021) : 229–35. http://dx.doi.org/10.5194/isprs-archives-xliii-b4-2021-229-2021.

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Abstract. Tracking the members of civil protection or emergency teams is still an open issue. Although outdoors tracking is routinely performed using well-seasoned techniques such as GNSS, this same problem must be still solved for indoors situations. There exist several approaches for indoor positioning, but these are not appropriate for tracking emergency staff in real-time: some of these approaches rely on existing infrastructures; others have not been tested in light devices in real-time; none offers a combined solution. The IOPES project seeks to solve or at least alleviate this problem by building a portable, unobtrusive, lightweight device combining GNSS for outdoor positioning and visual-inertial odometry / SLAM for the indoors case. This work, the third of the IOPES series, presents the analysis of the performance results obtained after developing and testing the first IOPES prototype. To do it, the operational aspects of the prototype, the real-life scenarios where the tests took place and the actual results thus obtained are described.

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Zhu, Ruihui, Yunjia Wang, Hongji Cao, Baoguo Yu, Xingli Gan, Lu Huang, Heng Zhang, Shuang Li, Haonan Jia et Jianqiang Chen. « RTK/Pseudolite/LAHDE/IMU-PDR Integrated Pedestrian Navigation System for Urban and Indoor Environments ». Sensors 20, n^o 6 (24 mars 2020) : 1791. http://dx.doi.org/10.3390/s20061791.

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This paper presents an evaluation of real-time kinematic (RTK)/Pseudolite/landmarks assistance heuristic drift elimination (LAHDE)/inertial measurement unit-based personal dead reckoning systems (IMU-PDR) integrated pedestrian navigation system for urban and indoor environments. Real-time kinematic (RTK) technique is widely used for high-precision positioning and can provide periodic correction to inertial measurement unit (IMU)-based personal dead reckoning systems (PDR) outdoors. However, indoors, where global positioning system (GPS) signals are not available, RTK fails to achieve high-precision positioning. Pseudolite can provide satellite-like navigation signals for user receivers to achieve positioning in indoor environments. However, there are some problems in pseudolite positioning field, such as complex multipath effect in indoor environments and integer ambiguity of carrier phase. In order to avoid the limitation of these factors, a local search method based on carrier phase difference with the assistance of IMU-PDR is proposed in this paper, which can achieve higher positioning accuracy. Besides, heuristic drift elimination algorithm with the assistance of manmade landmarks (LAHDE) is introduced to eliminate the accumulated error in headings derived by IMU-PDR in indoor corridors. An algorithm verification system was developed to carry out real experiments in a cooperation scene. Results show that, although the proposed pedestrian navigation system has to use human behavior to switch the positioning algorithm according to different scenarios, it is still effective in controlling the IMU-PDR drift error in multiscenarios including outdoor, indoor corridor, and indoor room for different people.

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Pearce, Matthew, David H. Saunders, Peter Allison et Anthony P. Turner. « Indoor and Outdoor Context-Specific Contributions to Early Adolescent Moderate to Vigorous Physical Activity as Measured by Combined Diary, Accelerometer, and GPS ». Journal of Physical Activity and Health 15, n^o 1 (1 janvier 2018) : 40–45. http://dx.doi.org/10.1123/jpah.2016-0638.

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Background: The distribution of adolescent moderate to vigorous physical activity (MVPA) across multiple contexts is unclear. This study examined indoor and outdoor leisure time in terms of being structured or unstructured and explored relationships with total daily MVPA. Methods: Between September 2012 and January 2014, 70 participants (aged 11–13 y) from 4 schools in Edinburgh wore an accelerometer and global positioning system receiver over 7 days, reporting structured physical activity using a diary. Time spent and MVPA were summarized according to indoor/outdoor location and whether activity was structured/unstructured. Independent associations between context-specific time spent and total daily MVPA were examined using a multivariate linear regression model. Results: Very little time or MVPA was recorded in structured contexts. Unstructured outdoor leisure time was associated with an increase in total daily MVPA almost twice that of unstructured indoor leisure time [b value (95% confidence interval), 8.45 (1.71 to 14.48) vs 4.38 (0.20 to 8.22) minute increase per hour spent]. The association was stronger for time spent in structured outdoor leisure time [35.81 (20.60 to 52.27)]. Conclusions: Research and interventions should focus on strategies to facilitate time outdoors during unstructured leisure time and maximize MVPA once youth are outdoors. Increasing the proportion of youth engaging in structured activity may be beneficial given that, although time spent was limited, association with MVPA was strongest.

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Angelats, E., et J. A. Navarro. « TOWARDS A FAST, LOW-COST INDOOR MAPPING AND POSITIONING SYSTEM FOR CIVIL PROTECTION AND EMERGENCY TEAMS ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W8 (13 novembre 2017) : 9–15. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w8-9-2017.

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Civil protection and emergency teams work usually under very risky conditions that endanger their lives. One of the factors contributing to such risks is the lack of knowledge about their physical environment, especially when working indoors. Mapping and location indoor and outdoor technologies exist; for outdoors, very good levels of precision and accuracy may be obtained using offthe- shelf equipment; on the other side, and although good solutions for indoor environments are available, these require some extra pre-deployed infrastructure in the area to navigate, which is unacceptable in the case of emergency teams. It may be said, then, that no mature indoor + outdoor integrated solution providing the appropriate precision and accuracy for the purposes of emergency teams exist. In this paper, the assessment of a set of currently available sensors (IMUs, RGB-D cameras, GNSS receivers) and algorithms is presented to show that it is already possible to build such a solution relying on them – providing that appropriate (indoor) lightning and texture conditions exist.

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Liestøl, Gunnar. « Museums, Artefacts and Cultural Heritage Sites ». Journal of Media Innovations 7, n^o 1 (11 mai 2021) : 19–28. http://dx.doi.org/10.5617/jomi.8792.

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The relationships between museums, artefacts and original sites are complex. How may we use mobile augmented reality (AR) to bridge the gaps between both indoors and outdoors exhibitions as well as the opposition between central collections and the more peripheral sites of the original artefacts? In this paper we present two main cases (the Viking Ship Museum in Oslo and the Calmecac Museum in Mexico City) where we have experimented with bringing a digital copy of the displaced artefact back to its original environment, as well as bringing a digital copy of the original environment into the displaced or isolated object in the museum exhibition. Further, we report on a solution to solve the problem with indoor positioning (IPS) and how it can be seamlessly combined with GPS–based outdoor positioning for smooth transitions between inside and outside. Finally, these cases were tested with three different hardware platforms - tablets, smartphones and smartglasses.

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Gao, Fangzheng, Wenjun Tang, Jiacai Huang et Haiyang Chen. « Positioning of Quadruped Robot Based on Tightly Coupled LiDAR Vision Inertial Odometer ». Remote Sensing 14, n^o 12 (20 juin 2022) : 2945. http://dx.doi.org/10.3390/rs14122945.

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Quadruped robots, an important class of unmanned aerial vehicles, have broad potential for applications in education, service, industry, military, and other fields. Their independent positioning plays a key role for completing assigned tasks in a complex environment. However, positioning based on global navigation satellite systems (GNSS) may result in GNSS jamming and quadruped robots not operating properly in environments sheltered by buildings. In this paper, a tightly coupled LiDAR vision inertial odometer (LVIO) is proposed to address the positioning inaccuracy of quadruped robots, which have poor mileage information obtained though legs and feet structures only. With this optimization method, the point cloud data obtained by 3D LiDAR, the image feature information obtained by binocular vision, and the IMU inertial data are combined to improve the precise indoor and outdoor positioning of a quadruped robot. This method reduces the errors caused by the uniform motion model in laser odometer as well as the image blur caused by rapid movements of the robot, which can lead to error-matching in a dynamic scene; at the same time, it alleviates the impact of drift on inertial measurements. Finally, the quadruped robot in the laboratory is used to build a physical platform for verification. The experimental results show that the designed LVIO effectively realizes the positioning of four groups of robots with high precision and strong robustness, both indoors or outdoors, which verify the feasibility and effectiveness of the proposed method.

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Basiri, Anahid, Pouria Amirian, Adam Winstanley, Stuart Marsh, Terry Moore et Guillaume Gales. « Seamless Pedestrian Positioning and Navigation Using Landmarks ». Journal of Navigation 69, n^o 1 (22 juin 2015) : 24–40. http://dx.doi.org/10.1017/s0373463315000442.

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Many navigation services, such as car navigation services, provide users with praxic navigational instructions (such as “turn left after 200 metres, then turn right after 150 metres”), however people usually associate directions with visual cues (e.g. “turn right at the square”) when giving navigational instructions in their daily conversations. Landmarks can play an equally important role in navigation and routing services. Landmarks are unique and easy-to-recognise and remember features; therefore, in order to remember when exploring an unfamiliar environment, they would be assets. In addition, Landmarks can be found both indoors and outdoors and their locations are usually fixed. Any positioning techniques which use landmarks as reference points can potentially provide seamless (indoor and outdoor) positioning solutions. For example, users can be localised with respect to landmarks if they can take a photograph of a registered landmark and use an application for image processing and feature extraction to identify the landmark and its location. Landmarks can also be used in pedestrian-specific path finding services. Landmarks can be considered as an important parameter in a path finding algorithm to calculate a route passing more landmarks (to make the user visit a more tourist-focussed area, pass along an easier-to-follow route, etc.). Landmarks can also be used as a part of the navigational instructions provided to users; a landmark-based navigation service makes users sure that they are on the correct route, as the user is reassured by seeing the landmark whose information/picture has just been provided as a part of navigational instruction. This paper shows how landmarks can help improve positioning and praxic navigational instructions in all these ways.

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PAIGE, KIRSTEN. « On the Politics of Performing Wagner Outdoors : Open-Air Opera, Gesamtkunstwerk and the Third Reich’s ‘Forest Opera’, 1933–45 ». Journal of the Royal Musical Association 146, n^o 1 (4 février 2021) : 147–80. http://dx.doi.org/10.1017/rma.2020.26.

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AbstractThis article explores the politics of performing Wagner outdoors, focusing on the Waldoper in Sopot, Poland, and its operations under the Third Reich. Festival literature suggests that the Reich combined climatic deterministic logic with established open-air theatrical practice to implicate experiencing Wagnerian sounds outdoors as inculcating völkisch character in Poles, positioning the festival within the Reich’s imperial mission. However, this vision from ‘on high’ was undermined by bureaucratic disorganization and inefficiency, much like other Nazi artistic projects. The article concludes with a discussion of the post-war afterlives of the Waldoper and its attendant mythologies.

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Masiero, A., C. Toth, J. Gabela et G. Retscher. « ANALYSIS OF THE PERFORMANCE OF AN UWB-BASED COOPERATIVE POSITIONING FOR DIFFERENT CAR PLATOON CONFIGURATIONS ». International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B1-2022 (30 mai 2022) : 467–72. http://dx.doi.org/10.5194/isprs-archives-xliii-b1-2022-467-2022.

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Abstract. The increasing interest in autonomous vehicles motivates the researches aiming at developing reliable positioning system also in conditions challenging for the Global Navigation Satellite Systems (GNSS), such as in urban canyons, tunnels, under quite dense vegetation. The uso of Ultra Wide-Band (UWB) systems is among the quite well known methods for providing reasonable positioning results without exploiting GNSS. UWB systems are typically used indoors, however their use can be of interest also outdoors, in particular when the need is to ensure good positioning results over a quite small area. This paper investigates the use of UWB systems for positioning in the case of terrestrial vehicles, and, more specifically, it focuses on checking the influence of car platoon configurations on the performance of an UWB cooperative positioning system. In the considered tests, where a high percentage of UWB communications was successful, the obtained results show that the car configuration can have a quite remarkable impact on the positioning performance, doubling the obtained median error.

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Cheng, Rung-Shiang, Wei-Jun Hong, Jheng-Syun Wang et Kawuu W. Lin. « Seamless Guidance System Combining GPS, BLE Beacon, and NFC Technologies ». Mobile Information Systems 2016 (2016) : 1–12. http://dx.doi.org/10.1155/2016/5032365.

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Users rely increasingly on Location-Based Services (LBS) and automated navigation/guidance systems nowadays. However, while such services are easily implemented in outdoor environments using Global Positioning System (GPS) technology, a requirement still exists for accurate localization and guidance schemes in indoor settings. Accordingly, the present study proposes a system based on GPS, Bluetooth Low Energy (BLE) beacons, and Near Field Communication (NFC) technology. Through establishing graphic information and the design of algorithm, this study develops a guidance system for indoors and outdoors on smart phones, wishing to give user perfect smart life through this system. The proposed system is implemented on a smart phone and evaluated on a student campus environment. The experimental results confirm the ability of the proposed app to switch automatically from an outdoor mode to an indoor mode and to guide the user to requested target destination via the shortest possible route.

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Li, L., Q. Huang, K. Xu, G. Guo et R. Chen. « VEHICLE POSITIONING IN UNDERGROUND SPACE USING A SMART PHONE ». International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVI-3/W1-2022 (22 avril 2022) : 81–87. http://dx.doi.org/10.5194/isprs-archives-xlvi-3-w1-2022-81-2022.

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Abstract. Smartphones is a good choice for vehicle navigation since many navigation sensors are built-in with low cost advantage. However, it cannot provide reliable positioning information in underground space since GNSS is not available and IMU drift quickly. In this manuscript, a mixed navigation scheme for smartphone consumer is presented. It combines GNSS, INS, Non-Holonomic Constraint (NHC) and Bluetooth Low Energy (BLE) to provide reliable seamless navigation in both outdoors and underground. Some important problems including smartphone boresight misalignment, HNC level arm, GNSS and BLE time lag are discussed in the manuscript. The testing results show 3.1% /D horizontal positioning error in tunnel in INS/NHC positioning mode, and approximately 1 meter accuracy in underground parking garage in INS/NHC/BLE mode.

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Zandbergen, Paul A., et Sean J. Barbeau. « Positional Accuracy of Assisted GPS Data from High-Sensitivity GPS-enabled Mobile Phones ». Journal of Navigation 64, n^o 3 (7 juin 2011) : 381–99. http://dx.doi.org/10.1017/s0373463311000051.

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Utilizing both Assisted GPS (A-GPS) techniques and new high-sensitivity embedded GPS hardware, mobile phones are now able to achieve positioning in harsh environments such as urban canyons and indoor locations where older embedded GPS chips could not. This paper presents an empirical analysis of the positional accuracy of location data gathered using a high-sensitivity GPS-enabled mobile phone. The performance of the mobile phone is compared to that of regular recreational grade GPS receivers. Availability of valid GPS position fixes on the mobile phones tested was consistently close to 100% both outdoors and indoors. During static outdoor testing, positions provided by the mobile phones revealed a median horizontal error of between 5·0 and 8·5 m, substantially larger than those for regular autonomous GPS units by a factor of 2 to 3. Horizontal errors during static indoor testing were larger compared to outdoors, but the difference in accuracy between mobile phones and regular GPS receivers was reduced. Despite the modest performance of A-GPS on mobile phones, testing under various conditions revealed that very large errors are not very common. The maximum horizontal error during outdoor testing never exceeded 30 metres and during indoor testing never exceeded 100 metres. Combined with the relatively consistent availability of valid GPS position fixes under varying conditions, the current study has confirmed the reliability of A-GPS on mobiles phones as a source of location information for a range of different LBS applications.

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Granger, Catherine L., Linda Denehy, Christine F. McDonald, Louis Irving et Ross A. Clark. « Physical Activity Measured Using Global Positioning System Tracking in Non–Small Cell Lung Cancer ». Integrative Cancer Therapies 13, n^o 6 (7 juillet 2014) : 482–92. http://dx.doi.org/10.1177/1534735414542484.

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Introduction. Increasingly physical activity (PA) is being recognized as an important outcome in non–small cell lung cancer (NSCLC). We investigated PA using novel global positioning system (GPS) tracking individuals with NSCLC and a group of similar-aged healthy individuals. Methods. A prospective cross-sectional multicenter study. Fifty individuals with NSCLC from 3 Australian tertiary hospitals and 35 similar-aged healthy individuals without cancer were included. Individuals with NSCLC were assessed pretreatment. Primary measures were triaxial accelerometery (steps/day) and GPS tracking (outdoor PA behavior). Secondary measures were questionnaires assessing depression, motivation to exercise, and environmental barriers to PA. Between-group comparisons were analyzed using analysis of covariance. Results. Individuals with NSCLC engaged in significantly less PA than similar-aged healthy individuals (mean difference 2363 steps/day, P = .007) and had higher levels of depression ( P = .027) and lower motivation to exercise ( P = .001). Daily outdoor walking time ( P = .874) and distance travelled away from home ( P = .883) were not different between groups. Individuals with NSCLC spent less time outdoors in their local neighborhood area ( P < .001). A greater number of steps per day was seen in patients who were less depressed ( r = .39) or had better access to nonresidential destinations such as shopping centers ( r = .25). Conclusion. Global positioning system tracking appears to be a feasible methodology for adult cancer patients and holds promise for use in future studies investigating PA and or lifestyle behaviors.

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Salbach, Nancy M., Ruth Barclay, Sandra C. Webber, C. A. Jones, Nancy E. Mayo, Lisa M. Lix, Jacquie Ripat, Theresa Grant, Cornelia van Ineveld et Philip D. Chilibeck. « A theory-based, task-oriented, outdoor walking programme for older adults with difficulty walking outdoors : protocol for the Getting Older Adults Outdoors (GO-OUT) randomised controlled trial ». BMJ Open 9, n^o 4 (avril 2019) : e029393. http://dx.doi.org/10.1136/bmjopen-2019-029393.

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IntroductionA theory-based, task-oriented, community walking programme can increase outdoor walking activity among older adults to optimise functional independence, social participation and well-being. The study objective is to determine if there is a difference in the change in outdoor walking activity from baseline to 10 weeks, 5.5 months and 12 months after receiving a 1-day interactive workshop and outdoor walking programme (Getting Older Adults Outdoors (GO-OUT)) compared with the workshop and weekly reminders (WR) in older adults with difficulty walking outdoors.Methods and analysisA randomised controlled trial is being conducted in four urban Canadian communities. We will stratify 240 individuals by site and participant type (ie, individual vs spousal/friend pair) and randomise to either the GO-OUT or WR intervention. The GO-OUT intervention involves a 1-day workshop, where participants complete eight interactive stations to build knowledge and skills to walk outside, followed by a 10-week group outdoor walking programme (two 1-hour sessions/week) led by a physiotherapist or kinesiologist in parks. The WR intervention consists of the same workshop and 10 weekly telephone reminders to facilitate outdoor walking. The primary outcome measure is mean outdoor walking time in minutes/week derived from accelerometry and global positioning system data. GO-OUT is powered to detect an effect size of 0.4, given α=0.05, β=0.20, equal number of participants/group and a 20% attrition rate. Secondary outcomes include physical activity, lifespace mobility, participation, health-related quality of life, balance, leg strength, walking self-efficacy, walking speed, walking distance/endurance and mood.Ethics and disseminationGO-OUT has received ethics approval at all sites. A Data Safety Monitoring Board will monitor adverse events. We will disseminate findings through lay summaries, conference presentations and journal articles.Trial registration numberNCT03292510 (Pre-results).

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Zhang, Yuan Liang, Jong Ho Park, Nam O. Sel et Kil To Chong. « Robot Navigation Using a DR/GPS Data Fusion ». Applied Mechanics and Materials 392 (septembre 2013) : 261–66. http://dx.doi.org/10.4028/www.scientific.net/amm.392.261.

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Dead Reckoning (DR) is one of the frequently used navigation system for a mobile robot. It provides short term navigation information but its error can accumulate over time without limit. The Global Positioning System (GPS) can be used for localization and navigation outdoors wherein the removal of the SA Policy improved the accuracy of the GPS for civilian use but the error is still quite large. Standard Differential GPS (DGPS) can be used to achieve an error of less than one meter but the costs are prohibitive in terms of commercializing it into the mass market. In this research study, a cheap GPS receiver was used for the navigation system of a mobile robot outdoors in which a new Kalman-filter based DR/GPS data fusion method was utilized. This proposed method is based on the characteristics of the GPS receiver. Fusing the data from the GPS receiver and the DR system provided precise navigation information for the mobile robot. Simulation was performed to check and validate the effectiveness of the proposed fusion method and good results showed its potential for mobile robot navigation outdoors.

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Pascacio, Pavel, Sven Casteleyn, Joaquín Torres-Sospedra, Elena Simona Lohan et Jari Nurmi. « Collaborative Indoor Positioning Systems : A Systematic Review ». Sensors 21, n^o 3 (2 février 2021) : 1002. http://dx.doi.org/10.3390/s21031002.

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Research and development in Collaborative Indoor Positioning Systems (CIPSs) is growing steadily due to their potential to improve on the performance of their non-collaborative counterparts. In contrast to the outdoors scenario, where Global Navigation Satellite System is widely adopted, in (collaborative) indoor positioning systems a large variety of technologies, techniques, and methods is being used. Moreover, the diversity of evaluation procedures and scenarios hinders a direct comparison. This paper presents a systematic review that gives a general view of the current CIPSs. A total of 84 works, published between 2006 and 2020, have been identified. These articles were analyzed and classified according to the described system’s architecture, infrastructure, technologies, techniques, methods, and evaluation. The results indicate a growing interest in collaborative positioning, and the trend tend to be towards the use of distributed architectures and infrastructure-less systems. Moreover, the most used technologies to determine the collaborative positioning between users are wireless communication technologies (Wi-Fi, Ultra-WideBand, and Bluetooth). The predominant collaborative positioning techniques are Received Signal Strength Indication, Fingerprinting, and Time of Arrival/Flight, and the collaborative methods are particle filters, Belief Propagation, Extended Kalman Filter, and Least Squares. Simulations are used as the main evaluation procedure. On the basis of the analysis and results, several promising future research avenues and gaps in research were identified.

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Fernández, Pedro J., José Santa et Antonio F. Skarmeta. « Hybrid Positioning for Smart Spaces : Proposal and Evaluation ». Applied Sciences 10, n^o 12 (13 juin 2020) : 4083. http://dx.doi.org/10.3390/app10124083.

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Positioning capabilities have become essential in context-aware user services, which make easier daily activities and let the emergence of new business models in the trendy area of smart cities. Thanks to wireless connection capabilities of smart mobile devices and the proliferation of wireless attachment points in buildings, several positioning systems have appeared in the last years to provide indoor positioning and complement GPS for outdoors. Wi-Fi fingerprinting is one of the most remarkable approaches, although ongoing smart deployments in the area of smart cities can offer extra possibilities to exploit hybrid schemes, in which the final location takes into account different positioning sources. In this paper we propose a positioning system that leverages common infrastructure and services already present in smart spaces to enhance indoor positioning. Thus, GPS and WiFi are complemented with access control services (i.e., ID card) or Bluetooth Low Energy beaconing, to determine the user location within a smart space. Better position estimations can be calculated by hybridizing the positioning information coming from different technologies, and a handover mechanism between technologies or algorithms is used exploiting semantic information saved in fingerprints. The solution implemented is highly optimized by reducing tedious computation, by means of opportunistic selection of fingerprints and floor change detection, and a battery saving subsystem reduces power consumption by disabling non-needed technologies. The proposal has been showcased over a smart campus deployment to check its real operation and assess the positioning accuracy, experiencing the noticeable advantage of integrating technologies usually available in smart spaces and reaching an average real error of 4.62 m.

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TREUILLET, SYLVIE, et ERIC ROYER. « OUTDOOR/INDOOR VISION-BASED LOCALIZATION FOR BLIND PEDESTRIAN NAVIGATION ASSISTANCE ». International Journal of Image and Graphics 10, n^o 04 (octobre 2010) : 481–96. http://dx.doi.org/10.1142/s0219467810003937.

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The most challenging issue facing the navigation assistive systems for the visually impaired is the instantaneous and accurate spatial localization of the user. Most of the previously proposed systems are based on global positioning system (GPS) sensors. However, the accuracy of low-cost versions is insufficient for pedestrian use. Furthermore, GPS-based systems are confined to outdoor navigation and experience severe signal losts in urban areas. This paper presents a new approach for localizing a person by using a single-body-mounted camera and computer vision techniques. Instantaneous accurate localization and heading estimates of the person are computed from images as the user progresses along a memorized path. A portable prototype has been tested for outdoor as well as indoor pedestrian use. Experimental results demonstrate the effectiveness of the vision-based localization: the accuracy is sufficient for making it possible to guide and maintain the blind person within a navigation corridor less than 1 m wide along the intended path. In combination with a suitable guiding interface, such a localization system will be convenient to assist the visually impaired in their everyday movements outdoors as well as indoors.

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Palmiste, Ülar, Jarek Kurnitski et Hendrik Voll. « Design criteria for outdoor air intakes and exhaust air outlets located on an external wall ». E3S Web of Conferences 172 (2020) : 09008. http://dx.doi.org/10.1051/e3sconf/202017209008.

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Optimal placement of outdoor air intakes and exhaust outlets is a source control measure to avoid the degradation of air quality at the air intakes. Re-entrainment is an occasional air pollution instance that happens if pollutants in the exhaust air stream, after being discharged to outdoors, are transferred back to outdoor air intake location due to unfavorable meteorological conditions and inadequate positioning of the air intakes and exhaust outlets. In engineering practice, it is impractical to always conduct detailed dispersion modeling due to the complexity of airflow phenomena in the urban environments, and therefore, engineers rely on prescriptive design guidelines or simplified empirical models published in technical literature and regulation documents. Commonly, the design guidelines to avoid the re-entrainment phenomenon are for buildings with rooftop exhaust stacks, but the exhaust outlets might also be situated on the building façade. The objective of this paper is to overview the existing design guidelines for the placement of horizontal air intakes and exhaust outlets. Technical engineering literature, including international standards, codes, and guidebooks is reviewed to extract both qualitative and quantitative design guidelines relevant to the placement of air intakes and exhausts on an external wall.

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Zhao, Yinzhi, Jiming Guo, Jingui Zou, Peng Zhang, Di Zhang, Xin Li, Gege Huang et Fei Yang. « A Holistic Approach to Guarantee the Reliability of Positioning Based on Carrier Phase for Indoor Pseudolite ». Applied Sciences 10, n^o 4 (11 février 2020) : 1199. http://dx.doi.org/10.3390/app10041199.

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The integrity monitoring algorithm based on pseudorange observations has been widely used outdoors and plays an important role in ensuring the reliability of positioning. However, pseudorange observations are greatly affected by the error sources such as multipath, clock drift, and noise in indoor pseudolite system, thus the pseudorange observations cannot be applied to high-precision indoor positioning. In general, double differenced (DD) carrier phase observations are used to obtain a high-precision indoor positioning result. What’s more, the carrier phase-based integrity monitoring (CRAIM) algorithm is applied to identify and exclude potential faults of the pseudolites. In this article, a holistic method is proposed to ensure the accuracy and reliability of positioning results. Firstly, if the reference pseudolite operates normally, extended Kalman filter is used for parameter estimation on the premise that the number of common pseudolites meets positioning requirements. Secondly, the innovation sequence in the Kalman filter is applied to construct test statistics and the corresponding threshold is determined from the Chi distribution with a given probability of false alert. The pseudolitehorizontal protection level (HPL) is calculated by the threshold and a prior probability of missed detection. Finally, compared the test statistics with the threshold to exclude the faultypseudolite for the reliability of positioning. The experiment results show that the proposed method improves the accuracy and stability of the results through faults detection and exclusion. This method ensures accuracies at the centimeter level for dynamic experiments and millimeter levels for static ones.

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Vedder, Benjamin, Jonny Vinter et Magnus Jonsson. « A Low-Cost Model Vehicle Testbed with Accurate Positioning for Autonomous Driving ». Journal of Robotics 2018 (18 novembre 2018) : 1–10. http://dx.doi.org/10.1155/2018/4907536.

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Accurate positioning is a requirement for many applications, including safety-critical autonomous vehicles. To reduce cost and at the same time improving accuracy for positioning of autonomous vehicles, new methods, tools, and research platforms are needed. We have created a low-cost testbed consisting of electronics and software that can be fitted on model vehicles allowing them to follow trajectories autonomously with a position accuracy of around 3 cm outdoors. The position of the vehicles is derived from sensor fusion between Real-Time Kinematic Satellite Navigation (RTK-SN), odometry, and inertial measurement and performs well within a 10 km radius from a base station. Trajectories to be followed can be edited with a custom GUI, where also several model vehicles can be controlled and visualized in real time. All software and Printed Circuit Boards (PCBs) for our testbed are available as open source to make customization and development possible. Our testbed can be used for research within autonomous driving, for carrying test equipment, and other applications where low cost and accurate positioning and navigation are required.

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Pagliari, D., L. Pinto, M. Reguzzoni et L. Rossi. « INTEGRATION OF KINECT AND LOW-COST GNSS FOR OUTDOOR NAVIGATION ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (15 juin 2016) : 565–72. http://dx.doi.org/10.5194/isprs-archives-xli-b5-565-2016.

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Since its launch on the market, Microsoft Kinect sensor has represented a great revolution in the field of low cost navigation, especially for indoor robotic applications. In fact, this system is endowed with a depth camera, as well as a visual RGB camera, at a cost of about 200$. The characteristics and the potentiality of the Kinect sensor have been widely studied for indoor applications. The second generation of this sensor has been announced to be capable of acquiring data even outdoors, under direct sunlight. The task of navigating passing from an indoor to an outdoor environment (and vice versa) is very demanding because the sensors that work properly in one environment are typically unsuitable in the other one. In this sense the Kinect could represent an interesting device allowing bridging the navigation solution between outdoor and indoor. In this work the accuracy and the field of application of the new generation of Kinect sensor have been tested outdoor, considering different lighting conditions and the reflective properties of the emitted ray on different materials. Moreover, an integrated system with a low cost GNSS receiver has been studied, with the aim of taking advantage of the GNSS positioning when the satellite visibility conditions are good enough. A kinematic test has been performed outdoor by using a Kinect sensor and a GNSS receiver and it is here presented.

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Pagliaria, D., L. Pinto, M. Reguzzoni et L. Rossi. « INTEGRATION OF KINECT AND LOW-COST GNSS FOR OUTDOOR NAVIGATION ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (15 juin 2016) : 565–72. http://dx.doi.org/10.5194/isprsarchives-xli-b5-565-2016.

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Since its launch on the market, Microsoft Kinect sensor has represented a great revolution in the field of low cost navigation, especially for indoor robotic applications. In fact, this system is endowed with a depth camera, as well as a visual RGB camera, at a cost of about 200$. The characteristics and the potentiality of the Kinect sensor have been widely studied for indoor applications. The second generation of this sensor has been announced to be capable of acquiring data even outdoors, under direct sunlight. The task of navigating passing from an indoor to an outdoor environment (and vice versa) is very demanding because the sensors that work properly in one environment are typically unsuitable in the other one. In this sense the Kinect could represent an interesting device allowing bridging the navigation solution between outdoor and indoor. In this work the accuracy and the field of application of the new generation of Kinect sensor have been tested outdoor, considering different lighting conditions and the reflective properties of the emitted ray on different materials. Moreover, an integrated system with a low cost GNSS receiver has been studied, with the aim of taking advantage of the GNSS positioning when the satellite visibility conditions are good enough. A kinematic test has been performed outdoor by using a Kinect sensor and a GNSS receiver and it is here presented.

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Sasiadek, J. Z., et Q. Wang. « Low cost automation using INS/GPS data fusion for accurate positioning ». Robotica 21, n^o 3 (13 mai 2003) : 255–60. http://dx.doi.org/10.1017/s0263574702004757.

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Low cost automation often requires accurate positioning. This happens whenever a vehicle or robotic manipulator is used to move materials, parts or minerals on the factory floor or outdoors. In last few years, such vehicles and devices are mostly autonomous. This paper presents the method of sensor fusion based on the Adaptive Fuzzy Kalman Filtering. This method has been applied to fuse position signals from the Global Positioning System (GPS) and Inertial Navigation System (INS) for the autonomous mobile vehicles. The presented method has been validated in 3-D environment and is of particular importance for guidance, navigation, and control of mobile, autonomous vehicles. The Extended Kalman Filter (EKF) and the noise characteristic have been modified using the Fuzzy Logic Adaptive System and compared with the performance of regular EKF. It has been demonstrated that the Fuzzy Adaptive Kalman Filter gives better results (more accurate) than the EKF. The presented method is suitable for real-time control and is relatively inexpensive. Also, it applies to fusion process with sensors different than INS or GPS.

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Kurti, Arianit, Daniel Spikol et Marcelo Milrad. « Bridging outdoors and indoors educational activities in schools with the support of mobile and positioning technologies ». International Journal of Mobile Learning and Organisation 2, n^o 2 (2008) : 166. http://dx.doi.org/10.1504/ijmlo.2008.019767.

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Richter, Philipp, et Manuel Toledano-Ayala. « Ubiquitous and Seamless Localization : Fusing GNSS Pseudoranges and WLAN Signal Strengths ». Mobile Information Systems 2017 (2017) : 1–16. http://dx.doi.org/10.1155/2017/8260746.

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Ubiquitous global positioning is not feasible by GNSS alone, as it lacks accurate position fixes in dense urban centres and indoors. Hybrid positioning methods have been developed to aid GNSS in those environments. Fingerprinting localization in wireless local area networks (WLANs) is a promising aiding system because of its availability, accuracy, and error mechanisms opposed to that of GNSS. This article presents a low-cost approach to ubiquitous, seamless positioning based on a particle filter integrating GNSS pseudoranges and WLAN received signal strength indicators (RSSIs). To achieve accurate location estimates indoors/outdoors and in the transition zones, appropriate likelihood functions are essential as they determine the influence of each sensor information on the position estimate. We model the spatial RSSI distributions with Gaussian processes and use these models to predict RSSIs at the particle’s positions to obtain point estimates of the RSSI likelihood function. The particle filter’s performance is assessed with real data of two test trajectories in an environment challenging for GNSS and WLAN fingerprinting localization. Outcomes of an extended Kalman filter using pseudoranges and a WLAN position as observation is included as benchmark. The proposed algorithm achieves accurate and robust seamless localization with a median accuracy of five meters.

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Retscher, Guenther, Jonathan Kleine et Lisa Whitemore. « Trilateration approaches for seamless out-/indoor GNSS and Wi-Fi smartphone positioning ». Journal of Applied Geodesy 13, n^o 1 (28 janvier 2019) : 47–61. http://dx.doi.org/10.1515/jag-2018-0022.

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Abstract More and more sensors and receivers are found nowadays in smartphones which can enable and improve positioning for Location-based Services and other navigation applications. Apart from inertial sensors, such as accelerometers, gyroscope and magnetometer, receivers for Wireless Fidelity (Wi-Fi) and GNSS signals can be employed for positioning of a mobile user. In this study, three trilateration methods for Wi-Fi positioning are investigated whereby the influence of the derivation of the relationship between the received signal strength (RSS) and the range to an Access Points (AP) are analyzed. The first approach is a straightforward resection for point determination and the second is based on the calculation of the center of gravity in a triangle of APs while weighting the received RSS. In the third method a differential approach is employed where as in Differential GNSS (DGNSS) corrections are derived and applied to the raw RSS measurements. In this Differential Wi-Fi (DWi-Fi) method, reference stations realized by low-cost Raspberry Pi units are used to model temporal RSS variations. In the experiments in this study two different indoor environments are used, one in a laboratory and the second in the entrance of an office building. The results of the second and third approach show position deviations from the ground truth of around 2 m in dependence of the geometrical point location. Furthermore, the transition between GNSS positioning outdoors and Wi-Fi localization indoors in the entrance area of the building is studied.

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Ashraf, Hur et Park. « Indoor Positioning on Disparate Commercial Smartphones Using Wi-Fi Access Points Coverage Area ». Sensors 19, n^o 19 (8 octobre 2019) : 4351. http://dx.doi.org/10.3390/s19194351.

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The applications of location-based services require precise location information of a user both indoors and outdoors. Global positioning system’s reduced accuracy for indoor environments necessitated the initiation of Indoor Positioning Systems (IPSs). However, the development of an IPS which can determine the user’s position with heterogeneous smartphones in the same fashion is a challenging problem. The performance of Wi-Fi fingerprinting-based IPSs is degraded by many factors including shadowing, absorption, and interference caused by obstacles, human mobility, and body loss. Moreover, the use of various smartphones and different orientations of the very same smartphone can limit its positioning accuracy as well. As Wi-Fi fingerprinting is based on Received Signal Strength (RSS) vector, it is prone to dynamic intrinsic limitations of radio propagation, including changes over time, and far away locations having similar RSS vector. This article presents a Wi-Fi fingerprinting approach that exploits Wi-Fi Access Points (APs) coverage area and does not utilize the RSS vector. Using the concepts of APs coverage area uniqueness and coverage area overlap, the proposed approach calculates the user’s current position with the help of APs’ intersection area. The experimental results demonstrate that the device dependency can be mitigated by making the fingerprinting database with the proposed approach. The experiments performed at a public place proves that positioning accuracy can also be increased because the proposed approach performs well in dynamic environments with human mobility. The impact of human body loss is studied as well.

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Makýš, Oto, Peter Krušinský, Renáta Korenková et Dominika Šrobárová. « Diagnostics of Wooden Poles Situated in the Open - Air Museum Using Sonic Tomography ». Civil and Environmental Engineering 14, n^o 1 (1 juin 2018) : 54–60. http://dx.doi.org/10.2478/cee-2018-0007.

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AbstractThe paper deals with the lifetime of wooden poles, situated in the archaeological open-air museum Liptovská Mara - Havránok, which were erected outdoors about 12 years ago. It is aimed at diagnosing their condition using sonic tomography. The poles differ from each other in the location, anchorage, and positioning in terms of the terrain slope. Investigation was focused on the free-standing poles (quasi sacrifice poles) and the poles that are part of the fortification (gates and walls). Measurements were carried out using the device Fakopp ArborSonic 3D Sonic Tomograph that has 18 sensors. It measures the sonic response (sound velocity) in a tree stem. Sound wave velocity within sound wood depends on its species, moisture content, and the direction of measurement. Measurements brought remarkable results.

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Cui, Xiao, Yong Yuan Qin, Qi Zhou et Qiang Wen Fu. « Shoe-Mounted Personal Navigation System Based on MEMS ». Advanced Materials Research 580 (octobre 2012) : 423–27. http://dx.doi.org/10.4028/www.scientific.net/amr.580.423.

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Shoe-mounted personal navigation system(PNS) based on MEMS is presented aiming at locating a person. Large error remains a problem in a standalone navigation system that uses only low cost MEMS IMU. This paper therefore proposes a approach which integrated with ZUPT and compass heading information in Kalman-based framework. The filter propagates and estimates the errors during the stance phase, which are fed back to the INS for compensating the accumulated error during walking. Finally, the performance of the proposed algorithm are verified by outdoors actual walking experiments of closed-loop path, were undertaken on campus of Northwestern Polytechnical University. The results show that the accuracy of positioning were almost always below 1% of the total traveled distance.

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Masiero, Andrea, Charles Toth, Jelena Gabela, Guenther Retscher, Allison Kealy, Harris Perakis, Vassilis Gikas et Dorota Grejner-Brzezinska. « Experimental Assessment of UWB and Vision-Based Car Cooperative Positioning System ». Remote Sensing 13, n^o 23 (30 novembre 2021) : 4858. http://dx.doi.org/10.3390/rs13234858.

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The availability of global navigation satellite systems (GNSS) on consumer devices has caused a dramatic change in every-day life and human behaviour globally. Although GNSS generally performs well outdoors, unavailability, intentional and unintentional threats, and reliability issues still remain. This has motivated the deployment of other complementary sensors in such a way that enables reliable positioning, even in GNSS-challenged environments. Besides sensor integration on a single platform to remedy the lack of GNSS, data sharing between platforms, such as in collaborative positioning, offers further performance improvements for positioning. An essential element of this approach is the availability of internode measurements, which brings in the strength of a geometric network. There are many sensors that can support ranging between platforms, such as LiDAR, camera, radar, and many RF technologies, including UWB, LoRA, 5G, etc. In this paper, to demonstrate the potential of the collaborative positioning technique, we use ultra-wide band (UWB) transceivers and vision data to compensate for the unavailability of GNSS in a terrestrial vehicle urban scenario. In particular, a cooperative positioning approach exploiting both vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) UWB measurements have been developed and tested in an experiment involving four cars. The results show that UWB ranging can be effectively used to determine distances between vehicles (at sub-meter level), and their relative positions, especially when vision data or a sufficient number of V2V ranges are available. The presence of NLOS observations is one of the principal factors causing a decrease in the UWB ranging performance, but modern machine learning tools have shown to be effective in partially eliminating NLOS observations. According to the obtained results, UWB V2I can achieve sub-meter level of accuracy in 2D positioning when GNSS is not available. Combining UWB V2I and GNSS as well V2V ranging may lead to similar results in cooperative positioning. Absolute cooperative positioning of a group of vehicles requires stable V2V ranging and that a certain number of vehicles in the group are provided with V2I ranging data. Results show that meter-level accuracy is achieved when at least two vehicles in the network have V2I data or reliable GNSS measurements, and usually when vehicles lack V2I data but receive V2V ranging to 2–3 vehicles. These working conditions typically ensure the robustness of the solution against undefined rotations. The integration of UWB with vision led to relative positioning results at sub-meter level of accuracy, an improvement of the absolute positioning cooperative results, and a reduction in the number of vehicles required to be provided with V2I or GNSS data to one.

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Wang, Youqing, Kun Zhao et Zhengqi Zheng. « A 3D Indoor Positioning Method of Wireless Network with Single Base Station in Multipath Environment ». Wireless Communications and Mobile Computing 2022 (14 avril 2022) : 1–13. http://dx.doi.org/10.1155/2022/3144509.

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The proliferation of indoor location-based services has increased the demand of indoor positioning technology. Severe multipath and coherence effects are the difference between signal propagation indoors and outdoors. Most existing indoor localization methods build their models in 2-dimensional space and try to avoid the influence of multipath. We propose a method to realize 3-dimensional indoor positioning with single base station by using multipath channel. The angles of multipath coherent signals are estimated by MIMO antenna and the delays are estimated by OFDM signal. To avoid the complicated calculation in joint estimation of angles and delays in 3-dimensional space, the angles and delays are estimated separately and matched by the proposed algorithm. The line-of-sight channel is differentiated by time delay, and the reflection paths for non-line-of-sight channels are established with angle information and indoor maps. Finally, combine the angle information of the reflection paths and the line-of-sight path to obtain the target position in 3-dimensional indoor space. We verified the method through simulation in an indoor space of 6 m × 8 m × 4.5 m . The positioning errors are submeter level in 95 % cases and less than 0.4m in 60 % cases. The proposed method requires only one base station and can be applied in most wireless networks. Compared with existing indoor localization methods, it has lower computational complexity and higher application potential.

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Gualda, David, María Carmen Pérez-Rubio, Jesús Ureña, Sergio Pérez-Bachiller, José Manuel Villadangos, Álvaro Hernández, Juan Jesús García et Ana Jiménez. « LOCATE-US : Indoor Positioning for Mobile Devices Using Encoded Ultrasonic Signals, Inertial Sensors and Graph-Matching ». Sensors 21, n^o 6 (10 mars 2021) : 1950. http://dx.doi.org/10.3390/s21061950.

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Indoor positioning remains a challenge and, despite much research and development carried out in the last decade, there is still no standard as with the Global Navigation Satellite Systems (GNSS) outdoors. This paper presents an indoor positioning system called LOCATE-US with adjustable granularity for use with commercial mobile devices, such as smartphones or tablets. LOCATE-US is privacy-oriented and allows every device to compute its own position by fusing ultrasonic, inertial sensor measurements and map information. Ultrasonic Local Positioning Systems (U-LPS) based on encoded signals are placed in critical zones that require an accuracy below a few decimeters to correct the accumulated drift errors of the inertial measurements. These systems are well suited to work at room level as walls confine acoustic waves inside. To avoid audible artifacts, the U-LPS emission is set at 41.67 kHz, and an ultrasonic acquisition module with reduced dimensions is attached to the mobile device through the USB port to capture signals. Processing in the mobile device involves an improved Time Differences of Arrival (TDOA) estimation that is fused with the measurements from an external inertial sensor to obtain real-time location and trajectory display at a 10 Hz rate. Graph-matching has also been included, considering available prior knowledge about the navigation scenario. This kind of device is an adequate platform for Location-Based Services (LBS), enabling applications such as augmented reality, guiding applications, or people monitoring and assistance. The system architecture can easily incorporate new sensors in the future, such as UWB, RFiD or others.

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Zhao, Yun. « Study on the Improvement of Color Image Enhancement Algorithm for Robot Vision System ». Applied Mechanics and Materials 651-653 (septembre 2014) : 880–84. http://dx.doi.org/10.4028/www.scientific.net/amm.651-653.880.

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Under the influence of external dynamic lighting or outdoors strong light, image color have a great influence on rapid and accurate positioning of the robot, which requires the robot vision system to obtain the high quality of color image. This paper uses the image pixel conversion ratio algorithm to improve the image recognition algorithm of robot vision system, and the use of multi threshold segmentation technology carries out restructure for image, it can get the high resolution image enhancement effect. In order to realize the algorithm, the form of using VB programming carries out algorithm implementation, and then the image enhancement can calculate the enhanced results table of image color curve distribution and different segmentation threshold image resolution. From the simulation results, this algorithm can enhance the image color effect, which provides technical support for the development and design of robot vision system.

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Fang, Zhixiang, Yuxin Jiang, Hong Xu, Shih-Lung Shaw, Ling Li et Xuexian Geng. « An Invisible Salient Landmark Approach to Locating Pedestrians for Predesigned Business Card Route of Pedestrian Navigation ». Sensors 18, n^o 9 (19 septembre 2018) : 3164. http://dx.doi.org/10.3390/s18093164.

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Visual landmarks are important navigational aids for research into and design of applications for last mile pedestrian navigation, e.g., business card route of pedestrian navigation. The business card route is a route between a fixed origin (e.g., campus entrance) to a fixed destination (e.g., office). The changing characteristics and combinations of various sensors’ data in smartphones or navigation devices can be viewed as invisible salient landmarks for business card route of pedestrian navigation. However, the advantages of these invisible landmarks have not been fully utilized, despite the prevalence of GPS and digital maps. This paper presents an improvement to the Dempster–Shafer theory of evidence to find invisible landmarks along predesigned pedestrian routes, which can guide pedestrians by locating them without using digital maps. This approach is suitable for use as a “business card” route for newcomers to find their last mile destinations smoothly by following precollected sensor data along a target route. Experiments in real pedestrian navigation environments show that our proposed approach can sense the location of pedestrians automatically, both indoors and outdoors, and has smaller positioning errors than purely GPS and Wi-Fi positioning approaches in the study area. Consequently, the proposed methodology is appropriate to guide pedestrians to unfamiliar destinations, such as a room in a building or an exit from a park, with little dependency on geographical information.

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Beavington, Lee, et Jesse Jewell. « GPS Ecocache ». American Association of Philosophy Teachers Studies in Pedagogy 4 (2018) : 161–80. http://dx.doi.org/10.5840/aaptstudies201922539.

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The Global Positioning System (GPS) has been used as an experiential educational tool for nearly twenty years. Innovative educators have expanded the educational use of GPS devices beyond the geocache. This essay uses Leopold’s land ethic as a philosophical framework for relational education, and outlines the practical application of the GPS ecocache. The experiential, place-based ecocache has learners navigate to sites of ecological significance (e.g., plants, animals, landforms), where they must answer a question or riddle related to this site. We discuss the contradictory nature of using a gadget to connect with the outdoors, and integrate the GPS ecocache with Kolb’s model of experiential education. Ultimately, we hope to cultivate the values of Leopold’s land ethic through the use of a ubiquitously available device, and for learners to engage in relational pedagogy relevant to ecology, geography, environmental ethics, philosophy of science, philosophy of education and other courses concerned with human-nature connection and the nature of space.

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Nguyen, Duy Anh, et Minh Khoi Huynh. « A Research on Locating AGV via RSS Signals ». Applied Mechanics and Materials 889 (mars 2019) : 418–24. http://dx.doi.org/10.4028/www.scientific.net/amm.889.418.

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We are now living in an era of advanced technology, where every part of daily life is related to each other via many kinds of wireless connection. The fourth industrial revolution is now heading toward many kinds of network connecting in real-time which can boost productivity and performance among many manufacturers. In particular, a production manager wanted to know how many automated guided vehicles (AGV) were deployed in a warehouse at that moment; modern farmers wanted to know how many harvesting robots were operating, etc. Therefore, navigating is one of the main elements to handle these tasks. Although we have already applied Global Positioning System (GPS) to the outdoors so far, they still had some limitations, especially on deploying between indoor like houses, buildings which GPS signals are unable to reach. In this paper, we proposed a technique in order to recognize AGV and the distance between them via Received Signal Strength Indicator (RSSI) technique. In addition, we developed a way to store these data on a server for last long usage.

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Jin, Gu, Su Xiao, Lai Hanrong, Zhang Bin et Zhang Yawei. « Bush spherical center detection algorithm based on depth camera 3D point cloud ». Journal of Physics : Conference Series 2417, n^o 1 (1 décembre 2022) : 012034. http://dx.doi.org/10.1088/1742-6596/2417/1/012034.

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Automated pruning is an inevitable trend in the improvement of modern gardens. In order to provide necessary information for automatic garden robots and satisfy the requirement of target detection and positioning during pruning, this paper proposed a bush spherical center detection algorithm based on a 3D depth camera point cloud. Firstly, the depth camera collected the bush image, and the results were aligned to the depth image to obtain the 3D point cloud of bush. Then the ROI was extracted by preprocessing, and the 3D point clouds of bush was obtained after filtering and coordinate transformation. Finally, the spherical center coordinates of the bush were extracted by the minimum bounding box method. Four groups of tests on the bush spherical coordinates detection were carried out outdoors. The maximum location error and the minimum location error of the spherical bush center were 10.23mm and 8.65 mm, respectively, and the average location error was 9.51mm. The bush spherical center detection algorithm based on depth camera 3D point clouds proposed in this paper provides a technical reference for the information acquisition of automatic pruning robot.

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Merlin, A., B. George, L. Malassenet et L. Podgorski. « Durable protection of the surface of wood used outdoors : material constraints, problems and approaches to solutions ». MATEC Web of Conferences 149 (2018) : 01016. http://dx.doi.org/10.1051/matecconf/201814901016.

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The aesthetic durability of wooden structures is a major challenge for the use of this material in construction. Wood is used for its technical performances but also for its architectural qualities and its aesthetic perception. The premature aging of the wooden structures is detrimental because these disorders, even if they do not affect the strength of the structures, are mostly irremediable. The surface protection of wood is generally ensured by the use of a finish, whose essential role is to protect wood from climatic aggressions (water, solar radiation, oxygen, ...). The secondary wood processing industry consists of a series of manufacturing and processing activities, each containing a portion of the added value of the product. The application of a finish on a wood-based work is usually the last and most visible step in this value chain.In outdoor use, the protection of the wood surface with transparent finishes is not yet sufficiently durable to be able to compete with materials used in industrial carpentry such as PVC or aluminum. Opaque finishes generally provide more durable protection but they mask the appearance of the wood sought by users.With the aim of positioning wood in this construction sector, research on transparent finishes has focused on the efficiency and improvement of the durability of the protection of the surface appearance of structures. Faced with climatic aggressions, the optimum conservation of a structure is not only linked to the performance of the finish but also to the characteristics of the wood material. In particular, in order to fulfill its protective function, the finish film must be able to follow the dimensional variations of the wood it covers without breaking and without detachment. In addition to the criteria for the effectiveness of finishes in the protection of structures, the environmental impact must be considered with increasing attention. Currently, more than 80% of composite or solid wood products are still protected with solvent-based liquid products, which are an important source of VOC emissions. Does the solution come from photo-polymerizable systems that can be formulated with 100% dry matter either in liquid phase in reactive diluents or powdered?

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