Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851429
M. Werner, Lorenz Schauer, A. Scharf
The time-series nature of human movement inside buildings can be exploited for common tasks of location-based computing. With this paper, we propose to use Wi-Fi signal strength measurements directly to infer the trajectory in comparison with a database of trajectories removing the need for accurate map information or fingerprint databases. A trajectory consists of a time-series of sensor readings of all Wi-Fi signals in reach measured by a mobile device. Starting from these measurements, we discuss several possibilities of denoising, filtering and classification of trajectories to improve our approch. By using a variant of the Douglas-Peucker algorithm we reduce the amount of computation without severe degradation of classification performance. Furthermore, we increase platform scalability by using a fast filter operation based on the Jaccard index of presence of access points to prune irrelevant trajectories early. With respect to our setting, the Fréchet-distance between trajectories has proven to be a very good choice outperforming dynamic time warping. Finally, we intorduce several data-driven trajectory segmentation schemes in order to be able to match partial trajectories early. The evaluation is based on the collection of trajectories in specific situations including staircases, hallways and movement inside a single room. With this approach, we are able to reliably classify trajectories without an intermediate step of calculating spatial position. This results in increased stability with respect to local changes in the environment, as these changes only affect a small part of a longer trajectory.
{"title":"Reliable trajectory classification using Wi-Fi signal strength in indoor scenarios","authors":"M. Werner, Lorenz Schauer, A. Scharf","doi":"10.1109/PLANS.2014.6851429","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851429","url":null,"abstract":"The time-series nature of human movement inside buildings can be exploited for common tasks of location-based computing. With this paper, we propose to use Wi-Fi signal strength measurements directly to infer the trajectory in comparison with a database of trajectories removing the need for accurate map information or fingerprint databases. A trajectory consists of a time-series of sensor readings of all Wi-Fi signals in reach measured by a mobile device. Starting from these measurements, we discuss several possibilities of denoising, filtering and classification of trajectories to improve our approch. By using a variant of the Douglas-Peucker algorithm we reduce the amount of computation without severe degradation of classification performance. Furthermore, we increase platform scalability by using a fast filter operation based on the Jaccard index of presence of access points to prune irrelevant trajectories early. With respect to our setting, the Fréchet-distance between trajectories has proven to be a very good choice outperforming dynamic time warping. Finally, we intorduce several data-driven trajectory segmentation schemes in order to be able to match partial trajectories early. The evaluation is based on the collection of trajectories in specific situations including staircases, hallways and movement inside a single room. With this approach, we are able to reliably classify trajectories without an intermediate step of calculating spatial position. This results in increased stability with respect to local changes in the environment, as these changes only affect a small part of a longer trajectory.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127060271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851351
Yunus Terzioglu, S. E. Alper, K. Azgın, T. Akin
This paper presents an analog readout method for capacitive MEMS accelerometers in which the feedback actuation and capacitive detection are achieved simultaneously on the same electrode set. The presented circuit operates in closed-loop for improved linearity, and it is constructed in a hybrid platform package in which off-the-shelf discrete components are used together with the silicon-on-glass micro-accelerometer. The system is developed as a practical solution to reduce the complexity of the readout circuit and the accelerometer without degrading the overall system performance. Experimental results demonstrate 17.5 micro-g per square-root hertz velocity random walk, and 28 micro-g bias instability. Considering the estimated full scale range of 20 g, the dynamic range of the sensor is calculated to be close to 124 dB.
提出了一种在同一电极组上同时实现反馈驱动和电容检测的电容式加速度计模拟读出方法。所提出的电路在闭环中工作，以提高线性度，并且它是在一个混合平台封装中构建的，其中现成的分立元件与硅基玻璃微加速度计一起使用。该系统是一种实用的解决方案，可以在不降低系统整体性能的情况下降低读出电路和加速度计的复杂性。实验结果表明，随机漫步速度为17.5 μ g /平方根赫兹，偏差不稳定性为28 μ g。考虑到估计的满量程为20 g，传感器的动态范围计算接近124 dB。
{"title":"A capacitive MEMS accelerometer readout with concurrent detection and feedback using discrete components","authors":"Yunus Terzioglu, S. E. Alper, K. Azgın, T. Akin","doi":"10.1109/PLANS.2014.6851351","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851351","url":null,"abstract":"This paper presents an analog readout method for capacitive MEMS accelerometers in which the feedback actuation and capacitive detection are achieved simultaneously on the same electrode set. The presented circuit operates in closed-loop for improved linearity, and it is constructed in a hybrid platform package in which off-the-shelf discrete components are used together with the silicon-on-glass micro-accelerometer. The system is developed as a practical solution to reduce the complexity of the readout circuit and the accelerometer without degrading the overall system performance. Experimental results demonstrate 17.5 micro-g per square-root hertz velocity random walk, and 28 micro-g bias instability. Considering the estimated full scale range of 20 g, the dynamic range of the sensor is calculated to be close to 124 dB.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"6 36","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132880861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In a deeply-coupled GPS/INS integrated system, the use of the inertial aiding information can improve the tracking loop performance and make the system more robust. To meet this requirement, the inertial aiding information should have sufficient accuracy in short-term (such as the sampling interval of GPS, e.g. 1sec). The MEMS (Micro-Electro Mechanical System) IMU (Inertial Measurement Unit) can be a promising candidate due to its small size and low cost. There should be no doubt that MEMS INS (Inertial Navigation System) can aid the GPS receiver tracking loop by eliminating the dominant part of the motion dynamic stress, considering that the INS errors induced by the receiver motion dynamics is much less than the motion dynamic itself, when the receiver manoeuvres. So the only concern the side effect caused by MEMS INS, which determine whether MEMS IMU is qualified for deep integration, is its navigation error independent with the motion dynamics (i.e. manoeuvre-independent error). This paper assesses this side effect of MEMS INS in terms of providing Doppler aiding data in to the GPS carrier tracking loop through a thorough error propagation analysis. The Laplace transform analysis is applied to the simplified INS error dynamic equations under stationary condition and find out the transfer relation between the error sources and the velocity estimation errors. Then the velocity error is converted to Doppler aiding error and substitute into the GPS tracking loop to analyze the corresponding carrier phase error. Results show that the largest velocity error caused by maneuver-independent errors is less than 0.1m/s during the typical GPS update interval (e.g. 1 sec), which meets the real road test results. The consequent carrier phase tracking error caused by the maneuver-independent error of MEMS INS is below 1.2 degree, which is much less than receiver inherent errors (e.g. the oscillator error and thermal noise). Conclusion can be reached that even the low-end MEMS IMUs have the ability of aiding the GPS receiver signal tracking although it induces some additional errors.
在GPS/INS深度耦合集成系统中，利用惯性辅助信息可以提高跟踪回路的性能，增强系统的鲁棒性。为了满足这一要求，惯性辅助信息在短期内(如GPS的采样间隔，如1秒)应具有足够的精度。MEMS(微机电系统)惯性测量单元(IMU)因其体积小、成本低而成为一个有前途的候选器件。考虑到接收机运动时由接收机运动动力学引起的惯性导航系统误差远小于运动动力学本身，因此MEMS INS (Inertial Navigation System)可以通过消除运动动态应力的主导部分来辅助GPS接收机跟踪环路，这一点毋庸置疑。因此，决定MEMS IMU是否具有深度集成资格的唯一关注的副作用是其与运动动力学无关的导航误差(即与机动无关的误差)。本文通过全面的误差传播分析，评估了MEMS INS在向GPS载波跟踪环路提供多普勒辅助数据方面的这种副作用。对平稳条件下简化的惯导系统误差动力学方程进行拉普拉斯变换分析，找出误差源与速度估计误差之间的传递关系。然后将速度误差转化为多普勒辅助误差，代入GPS跟踪环路，分析相应的载波相位误差。结果表明，在典型的GPS更新间隔(如1秒)内，机动无关误差导致的最大速度误差小于0.1m/s，符合实际路测结果。由机动无关误差引起的载波相位跟踪误差小于1.2度，远小于接收机固有误差(如振荡器误差和热噪声)。可以得出结论，即使是低端的MEMS imu也具有辅助GPS接收机信号跟踪的能力，尽管它会产生一些额外的误差。
{"title":"Low-end MEMS IMU can contribute in GPS/INS deep integration","authors":"Yalong Ban, X. Niu, Tisheng Zhang, Quan Zhang, Wenfei Guo, Hongping Zhang","doi":"10.1109/PLANS.2014.6851440","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851440","url":null,"abstract":"In a deeply-coupled GPS/INS integrated system, the use of the inertial aiding information can improve the tracking loop performance and make the system more robust. To meet this requirement, the inertial aiding information should have sufficient accuracy in short-term (such as the sampling interval of GPS, e.g. 1sec). The MEMS (Micro-Electro Mechanical System) IMU (Inertial Measurement Unit) can be a promising candidate due to its small size and low cost. There should be no doubt that MEMS INS (Inertial Navigation System) can aid the GPS receiver tracking loop by eliminating the dominant part of the motion dynamic stress, considering that the INS errors induced by the receiver motion dynamics is much less than the motion dynamic itself, when the receiver manoeuvres. So the only concern the side effect caused by MEMS INS, which determine whether MEMS IMU is qualified for deep integration, is its navigation error independent with the motion dynamics (i.e. manoeuvre-independent error). This paper assesses this side effect of MEMS INS in terms of providing Doppler aiding data in to the GPS carrier tracking loop through a thorough error propagation analysis. The Laplace transform analysis is applied to the simplified INS error dynamic equations under stationary condition and find out the transfer relation between the error sources and the velocity estimation errors. Then the velocity error is converted to Doppler aiding error and substitute into the GPS tracking loop to analyze the corresponding carrier phase error. Results show that the largest velocity error caused by maneuver-independent errors is less than 0.1m/s during the typical GPS update interval (e.g. 1 sec), which meets the real road test results. The consequent carrier phase tracking error caused by the maneuver-independent error of MEMS INS is below 1.2 degree, which is much less than receiver inherent errors (e.g. the oscillator error and thermal noise). Conclusion can be reached that even the low-end MEMS IMUs have the ability of aiding the GPS receiver signal tracking although it induces some additional errors.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132951292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851387
Zhen Zhu, F. van Graas
This paper presents a systematic discussion on GPS C/A code cross correlation and its impact on signal acquisition, tracking and Ground-Based Augmentation System (GBAS) performance. Three types of cross correlation effects are investigated: 1) between two satellites that have approximately the same Doppler frequency; 2) between two satellites that have an offset at an integer number of kHz in Doppler frequency; 3) between a C/A code signal and a signal that consists of alternating zeros and ones. The first type of cross correlation has been well studied in the past decade, and its impact is often found similar to that of multipath. There exist some subtle, but important, differences between cross correlation and multipath, which will be discussed in this paper. Cross correlation cannot be treated as a random interference source, since it is inherently constrained by the Doppler frequency difference between the two satellites. Based on this constraint, the cross correlation functions will be analytically modeled in the time domain and in the frequency domain for each of the three types. All three types of cross correlation are potential threats to weak signal acquisition, PseudoRange tracking and carrier phase tracking. There are impacts on both mobile users and ground reference stations. More specifically, the PseudoRange tracking error will likely not be common between a ground reference and a mobile user, which becomes a concern for differential systems like GBAS. The PseudoRange error is not only a function of the Doppler offset and signal strength, but is also dependent on the tracking loop configuration. For example, the relative motion between the satellites and the antenna, the tracking loop bandwidth, coherent integration time and the carrier smoothing time constant all play key roles in the PseudoRange error model. It has been discovered in previous studies that a sufficiently large time constant in carrier smoothing provides effective mitigation for cross correlation errors. Most GPS users are protected against cross correlation in signal acquisition and tracking. In some worst-case scenarios, however, meter-level PseudoRange errors in GBAS may occur. As a result, cross correlation must be carefully monitored for high-accuracy safety of life applications. It can also falsely trigger other GBAS monitors, which may include the low power monitor and the signal deformation monitor. An overview of the implications of cross correlation on GBAS is provided in this paper.
{"title":"Implications of C/A code cross correlation on GPS and GBAS","authors":"Zhen Zhu, F. van Graas","doi":"10.1109/PLANS.2014.6851387","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851387","url":null,"abstract":"This paper presents a systematic discussion on GPS C/A code cross correlation and its impact on signal acquisition, tracking and Ground-Based Augmentation System (GBAS) performance. Three types of cross correlation effects are investigated: 1) between two satellites that have approximately the same Doppler frequency; 2) between two satellites that have an offset at an integer number of kHz in Doppler frequency; 3) between a C/A code signal and a signal that consists of alternating zeros and ones. The first type of cross correlation has been well studied in the past decade, and its impact is often found similar to that of multipath. There exist some subtle, but important, differences between cross correlation and multipath, which will be discussed in this paper. Cross correlation cannot be treated as a random interference source, since it is inherently constrained by the Doppler frequency difference between the two satellites. Based on this constraint, the cross correlation functions will be analytically modeled in the time domain and in the frequency domain for each of the three types. All three types of cross correlation are potential threats to weak signal acquisition, PseudoRange tracking and carrier phase tracking. There are impacts on both mobile users and ground reference stations. More specifically, the PseudoRange tracking error will likely not be common between a ground reference and a mobile user, which becomes a concern for differential systems like GBAS. The PseudoRange error is not only a function of the Doppler offset and signal strength, but is also dependent on the tracking loop configuration. For example, the relative motion between the satellites and the antenna, the tracking loop bandwidth, coherent integration time and the carrier smoothing time constant all play key roles in the PseudoRange error model. It has been discovered in previous studies that a sufficiently large time constant in carrier smoothing provides effective mitigation for cross correlation errors. Most GPS users are protected against cross correlation in signal acquisition and tracking. In some worst-case scenarios, however, meter-level PseudoRange errors in GBAS may occur. As a result, cross correlation must be carefully monitored for high-accuracy safety of life applications. It can also falsely trigger other GBAS monitors, which may include the low power monitor and the signal deformation monitor. An overview of the implications of cross correlation on GBAS is provided in this paper.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123292016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851459
Iris Wieser, Alberto Viseras Ruiz, Martin Frassl, M. Angermann, Joachim Mueller, M. Lichtenstern
Recent work has shown the feasibility of pedestrian and robotic indoor localization based only on maps of the magnetic field. To obtain a complete representation of the magnetic field without initial knowledge of the environment or any existing infrastructure, we consider an autonomous robotic platform to reduce limitations of economic or operational feasibility. Therefore, we present a novel robotic system that autonomously samples any measurable physical processes at high spatial resolution in buildings without any prior knowledge of the buildings' structure. In particular we focus on adaptable robotic shapes, kinematics and sensor placements to both achieve complete coverage in hardly accessible areas and not be limited to round shaped robots. We propose a grid based representation of the robot's configuration space and graph search algorithms, such as Best-First-Search and an adaption of Dijkstra's algorithm, to guarantee complete path coverage. In combination with an optical simultaneous localization and mapping (SLAM) algorithm, we present experimental results by sampling the magnetic field in an a priori unknown office with a robotic platform autonomously and completely.
{"title":"Autonomous robotic SLAM-based indoor navigation for high resolution sampling with complete coverage","authors":"Iris Wieser, Alberto Viseras Ruiz, Martin Frassl, M. Angermann, Joachim Mueller, M. Lichtenstern","doi":"10.1109/PLANS.2014.6851459","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851459","url":null,"abstract":"Recent work has shown the feasibility of pedestrian and robotic indoor localization based only on maps of the magnetic field. To obtain a complete representation of the magnetic field without initial knowledge of the environment or any existing infrastructure, we consider an autonomous robotic platform to reduce limitations of economic or operational feasibility. Therefore, we present a novel robotic system that autonomously samples any measurable physical processes at high spatial resolution in buildings without any prior knowledge of the buildings' structure. In particular we focus on adaptable robotic shapes, kinematics and sensor placements to both achieve complete coverage in hardly accessible areas and not be limited to round shaped robots. We propose a grid based representation of the robot's configuration space and graph search algorithms, such as Best-First-Search and an adaption of Dijkstra's algorithm, to guarantee complete path coverage. In combination with an optical simultaneous localization and mapping (SLAM) algorithm, we present experimental results by sampling the magnetic field in an a priori unknown office with a robotic platform autonomously and completely.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122275241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851477
Y. S. Choi, S. Lee, H. H. Choi, S. J. Lee, C. Park
Recent years, the GNSS has a diverse and wide application field. It provides the services that using the personal location information. But, for the some people, it is undesirable service. Therefore, these people start using the Personal Privacy Devices. A study about the impact of PPDs and effective countermeasure to PPDs are required. In this paper, we analyze the effect on the anti-jamming technique by the PPD jammer. And we show the effect of frequency swept jammer is removed by applying reduced-rank approach. We also analyzed the performance of reduced-rank approach.
{"title":"The improved spatial nuller with frequency swept jammer","authors":"Y. S. Choi, S. Lee, H. H. Choi, S. J. Lee, C. Park","doi":"10.1109/PLANS.2014.6851477","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851477","url":null,"abstract":"Recent years, the GNSS has a diverse and wide application field. It provides the services that using the personal location information. But, for the some people, it is undesirable service. Therefore, these people start using the Personal Privacy Devices. A study about the impact of PPDs and effective countermeasure to PPDs are required. In this paper, we analyze the effect on the anti-jamming technique by the PPD jammer. And we show the effect of frequency swept jammer is removed by applying reduced-rank approach. We also analyzed the performance of reduced-rank approach.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114302184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851374
Uri Schatzberg, L. Banin, Y. Amizur
The most common technology for outdoor positioning is GNSS. It is commonly used together with inertial sensors to compensate for poor reception and to help determine outlier measurements. In dense areas and indoors, GPS performance degrades or is not available at all. In indoor environments WiFi is one of the most popular radios; it is not surprising therefore that WiFi is often used for positioning. Specifically, time-based range measurements are emerging as the leading WiFi indoor positioning technology. Because this technique is quite new, its coverage might be limited in the near future. In this paper we present a highly accurate indoor positioning system which is based on a new WiFi technology (protocol) [1] and on MEMS inertial sensors. This system fuses together WiFi time-of-flight (ToF) range measurements, INS-based position velocity and attitude measurements, and pedometric information. It harnesses the advantages of each of these components while compensating for their individual disadvantages. WiFi ToF typically exhibits good performance but suffers from outliers, coverage and dependency of Access Points (AP) deployment geometry (DoP). The INS solution is highly accurate but diverges quickly with time. Pedometric information (PDR) suffers from overall poor performance, inability to determine direction of movement (heading) and exhausting per-user calibration. Our solution uses WiFi ToF measurements and pedometric information to restrict the INS solution. We describe the INS model, the fusion model, and show exciting results from a real world environment.
{"title":"Enhanced WiFi ToF indoor positioning system with MEMS-based INS and pedometric information","authors":"Uri Schatzberg, L. Banin, Y. Amizur","doi":"10.1109/PLANS.2014.6851374","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851374","url":null,"abstract":"The most common technology for outdoor positioning is GNSS. It is commonly used together with inertial sensors to compensate for poor reception and to help determine outlier measurements. In dense areas and indoors, GPS performance degrades or is not available at all. In indoor environments WiFi is one of the most popular radios; it is not surprising therefore that WiFi is often used for positioning. Specifically, time-based range measurements are emerging as the leading WiFi indoor positioning technology. Because this technique is quite new, its coverage might be limited in the near future. In this paper we present a highly accurate indoor positioning system which is based on a new WiFi technology (protocol) [1] and on MEMS inertial sensors. This system fuses together WiFi time-of-flight (ToF) range measurements, INS-based position velocity and attitude measurements, and pedometric information. It harnesses the advantages of each of these components while compensating for their individual disadvantages. WiFi ToF typically exhibits good performance but suffers from outliers, coverage and dependency of Access Points (AP) deployment geometry (DoP). The INS solution is highly accurate but diverges quickly with time. Pedometric information (PDR) suffers from overall poor performance, inability to determine direction of movement (heading) and exhausting per-user calibration. Our solution uses WiFi ToF measurements and pedometric information to restrict the INS solution. We describe the INS model, the fusion model, and show exciting results from a real world environment.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131408572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851369
S. Koslowski, Martin Braun, F. Jondral
This paper presents an adaption of a joint OFDM communication and radar system to filter bank multicarrier signals. Our results show that any signal which can be represented as a matrix of symbols spread out in the time-frequency domain in a regular fashion can be processed in the same way, making the results obtained from OFDM radar research applicable to FBMC radar. For OFDM, it was shown that the two-dimensional periodogram is a robust and optimal way to obtain a range-Doppler plane; this method can also be applied to FBMC radar. However, the absence of a cyclic prefix in FBMC modulated signals entails a faster deorthogonalisation of the received symbol for targets with a high range. This is mitigated by the higher processing gain in FBMC radar and the exploitation of the intrinsic interference.
{"title":"Using filter bank multicarrier signals for radar imaging","authors":"S. Koslowski, Martin Braun, F. Jondral","doi":"10.1109/PLANS.2014.6851369","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851369","url":null,"abstract":"This paper presents an adaption of a joint OFDM communication and radar system to filter bank multicarrier signals. Our results show that any signal which can be represented as a matrix of symbols spread out in the time-frequency domain in a regular fashion can be processed in the same way, making the results obtained from OFDM radar research applicable to FBMC radar. For OFDM, it was shown that the two-dimensional periodogram is a robust and optimal way to obtain a range-Doppler plane; this method can also be applied to FBMC radar. However, the absence of a cyclic prefix in FBMC modulated signals entails a faster deorthogonalisation of the received symbol for targets with a high range. This is mitigated by the higher processing gain in FBMC radar and the exploitation of the intrinsic interference.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131447532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851469
Cheng Chen, W. Chai, Yong Zhang, H. Roth
An accurate navigation system is an essential and important part for many applications carried out in the indoor environments. In the absence of absolute positioning information such as global positioning system, the navigation solution which relies on previous system states such as dead reckoning has shown disadvantage over long time running. In contrast, we introduce an novel and inexpensive sensor fusion based approach to solve the problem. The key idea is to use visual gyroscope as a complementary source for system heading estimation since it only depends on the scene observed by the camera. The introduced methods only requires a Kinect and a low cost inertial measurement unit. By using the same mechanism, the introduced method has been tested for the applications of both indoor mobile robot and pedestrian navigation. Field experiments have been carried out and corresponding results are presented.
{"title":"A RGB and D vision aided multi-sensor system for indoor mobile robot and pedestrian seamless navigation","authors":"Cheng Chen, W. Chai, Yong Zhang, H. Roth","doi":"10.1109/PLANS.2014.6851469","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851469","url":null,"abstract":"An accurate navigation system is an essential and important part for many applications carried out in the indoor environments. In the absence of absolute positioning information such as global positioning system, the navigation solution which relies on previous system states such as dead reckoning has shown disadvantage over long time running. In contrast, we introduce an novel and inexpensive sensor fusion based approach to solve the problem. The key idea is to use visual gyroscope as a complementary source for system heading estimation since it only depends on the scene observed by the camera. The introduced methods only requires a Kinect and a low cost inertial measurement unit. By using the same mechanism, the introduced method has been tested for the applications of both indoor mobile robot and pedestrian navigation. Field experiments have been carried out and corresponding results are presented.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127641523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851416
Tiantong Ren, M. Petovello
A collective bit synchronization approach is proposed for weak GNSS signals using multiple satellites. Monte Carlo simulation, a GNSS simulator test and a vehicular field test are used to assess the performance and the validity of this approach. The results show that collective bit synchronization, by combining 11 satellites with same signal power levels, has 8 dB sensitivity improvement over traditional ML bit synchronization. In the strong and weak signal mixed channel, collective bit synchronization can achieve perfect synchronization for 15 dB-Hz signal by only requiring two data bits. Collective bit synchronization is also shown to detect bit boundary positions more than 200 times faster than the traditional maximum likelihood bit synchronization for a weak signal.
{"title":"Collective bit synchronization for weak GNSS signals using multiple satellites","authors":"Tiantong Ren, M. Petovello","doi":"10.1109/PLANS.2014.6851416","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851416","url":null,"abstract":"A collective bit synchronization approach is proposed for weak GNSS signals using multiple satellites. Monte Carlo simulation, a GNSS simulator test and a vehicular field test are used to assess the performance and the validity of this approach. The results show that collective bit synchronization, by combining 11 satellites with same signal power levels, has 8 dB sensitivity improvement over traditional ML bit synchronization. In the strong and weak signal mixed channel, collective bit synchronization can achieve perfect synchronization for 15 dB-Hz signal by only requiring two data bits. Collective bit synchronization is also shown to detect bit boundary positions more than 200 times faster than the traditional maximum likelihood bit synchronization for a weak signal.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133386362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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