共查询到20条相似文献，搜索用时 46 毫秒
1.
全球定位系统（GPS）作为一种室外定位技术,已经在车辆导航、物流配送、灾害应急、军事打击等领域得到了广泛的应用。但对于室内环境下的定位．基于GPS定位技术的应用受到了极大的限制。相对于成熟的室外定位,室内定位作为一个新的研究热点．众多大学和公司都开展了相关研究．并提出了一系列室内定位技术．本文将阐述其中几种常用的技术．并就室内定位的相关应用进行简单展望。 相似文献
2.
基于位置的服务与射频识别技术将成为解决图书馆内用户及资源的定位导航的关键技术。本文从需求、原理、实现方式等方面探讨LBS与RFID结合实现图书馆室内定位导航的方法。 相似文献
3.
在室内无线光局域网中,可见光通信越来越引起了人们的关注。可见光通信具有发射功率高、无需申请频谱、无电磁干扰、节约能源等优点,因此注定会成为未来室内无线光通信的主角。提出了一种可见光局域网通信的模型,重点研究了基于无线光码分多址(WOCDMA)的信道共享方案。在以往的光正交码(OOC)基础上,采用了随机光码(random optical code)作为系统的扩频码,并对其相应的性能做了对比。 相似文献
4.
This paper addresses the potentials of ultra-wideband (UWB) through-wall imaging radars compared with conventional narrowband systems. The challenges that limit the utilization of high precision UWB systems are examined with the aim of mitigating them. These challenges include multi-path, pulse dispersion, and antenna effects on the pulse shape due to angles of transmission and arrival. The propagation of UWB signals through walls is a crucial factor in determining the success of UWB radar technology. UWB signals, when propagating through walls, not only suffer attenuation but also distortion due to dispersive properties of the walls. This paper examines time- and frequency-domain techniques for measuring the electromagnetic properties of construction materials in the UWB frequency range. The measured parameters provide valuable insights in appreciating the capabilities and limitations of the UWB technology. Special attention is paid to time gating as a mean to extract the direct-path signal from the multi-path components. Both single-pass and multi-pass models are discussed. Multi-pass models account for the multiple reflections within the wall while the single-pass model assumes the possibility of gating out a single transmission. The partition-dependent narrowband propagation model is modified to account for the ultra-wide bandwidth of the signal. The paper illustrates the application of the modified model in indoor environments. The modified model is helpful in estimating the link power budget. It is also useful in studying the performance of UWB systems for indoor communication and positioning applications. 相似文献
5.
Yasuhiro Yoshida Fumito Masui Michal Ptaszynski 《Information processing & management》2021,58(4):102542
In this paper, we propose a dialogue-based navigation system for narrow areas (e.g., buildings, etc.). In particular, we develop Campus Navigation Partner System (CNPS), intended for the use by freshmen (first-year students) who are likely to get lost in the new environment on the university campus (with the campus of Kitami Institute of Technology set as the experimental environment). The CNPS operates on a smartphone and has the functions of facility navigation and indoor information presentation. Indoor environment navigation is typically a problematic task because GNSS (Global Navigation Satellite System) signals cannot be received with sufficient accuracy within concrete walls. Therefore, we utilized natural language dialogue as a navigation method that guides the users within the facility using navigation messages and images. To investigate the effectiveness of the constructed system, we conducted practical experiments with freshmen and senior students of the university and evaluated the performance of the navigation functionality. Moreover, we investigated the general impressions of the system which we evaluated separately with both freshmen and senior students to clarify the differences in evaluation viewpoints between freshmen and users experienced in the campus environment (graduate students, etc.). 相似文献
6.
《Journal of The Franklin Institute》2022,359(16):9271-9295
In inertial navigation system and global navigation satellite system (INS/GNSS) integration, the practical stochastic measurement noise may be non-stationary heavy-tailed distribution due to outlier measurements induced by multipath and/or non-line-of-sight receptions of the original GNSS signals. To address the problem, a new switching Gaussian-heavy-tailed (SGHT) distribution is presented, which models the measurement noise with the help of switching between the Gaussian and the an existing heavy-tailed distribution. Then, utilizing two auxiliary parameters satisfying categorical and Bernoulli distributions respectively, we construct the SGHT distribution as a hierarchical Gaussian presentation. Furthermore, applying variational Bayesian inference, a novel SGHT distribution based robust Gaussian approximate filter is derived. Meanwhile, to reduce the computational complexity of the filtering process, an improved fixed-point iteration method is designed. Finally, the simulation of integrated navigation for an aircraft illustrates effectiveness and superiority of the proposed filter as compared the existing robust filters. 相似文献
7.
文章根据海洋和陆地环境的不同,系统论述了应用于海洋调查的各类导航定位技术,包括水面导航定位技术和水下导航定位技术。分析了各类技术的特点,并介绍了组合导航定位技术及其在海洋调查中的应用。 相似文献
8.
9.
创新驱动发展是国家战略，科技创新在我国全面创新中具有核心地位和引领作用。科技创新对我国北斗卫星导航定位系统及北斗卫星导航与位置服务产业发展意义重大，不仅对我国北斗产业发展指明了新方向，提出了新要求，也推动北斗产业步入了新的发展领域。文章通过探索浅析科技创新对我国北斗产业发展的驱动引领，为我国北斗系统积极参与国际竞争，提高我国北斗产业市场竞争力打下基础。 相似文献
10.
全球定位系统（GPS）软件接收机被广泛应用于卫星信号的精确定位。在接收机跟踪算法中,载波跟踪环路采用了Costas环,以保证对180度相位翻转不敏感;码跟踪环路采用了性能良好的归一化超前减滞后码相位鉴别器,以确保对信号的准确跟踪。最后提出了窄相关技术,在噪声和多径干扰条件下能够有效降低码跟踪误差。 相似文献
11.
12.
The presence of significant multipath propagation and heavy clutter in indoor environments imposes severe limitations on imaging through walls, rendering through-the-wall radar imaging a difficult and complex proposition. It is highly desirable to properly interpret the radar images and determine the contents of the indoor scene with a high level of confidence. Data collected from multiple vantage points around a structure can be used to improve imaging visibility into the indoor scene, which, in turn, enhances indoor target detection and localization. In this paper, we consider multi-location radar imaging. Image fusion techniques for combining synthetic aperture radar images acquired from multiple locations along two sides of an enclosed structure are presented. Supporting results, based on real-data collected in a semi-controlled laboratory environment, are provided which demonstrate the improved performance of the multiple location scheme compared to operation from a single vantage point. 相似文献
13.
与传统的车辆定位导航系统不同,面向个人的定位业务需求往往是偶发的,并且更注重导航设备的便携性、易用性。分析了基于GPS技术并结合Google Earth地标显示功能的手持式GPS定位系统,可以普及用于家庭监护。 相似文献
14.
《Journal of The Franklin Institute》2023,360(12):8704-8739
Indoor point cloud segmentation is necessary for many applications including object identification for indoor navigation, facility management and so on. In order to construct accurate segmentation system of indoor point cloud, this paper improves cloth simulation and uses it to control the segmentation of ceiling and floor. Simultaneously, we obtain the wall points according to the points’ density. We mainly introduce indoor objects control segmentation via clustering strategy. First, we generate the cutoff distance according to the angular resolution and scan distance. Second, we use exponential function to determine the local density. Third, the cluster center is determined according to the magnitude of product of local density and distance which are normalized. Finally, the points affiliated to a cluster are controlled one by one according to the distance between point and cluster center. Segmentation of objects is then realized based on the established clusters. Experiments indicate that the proposed algorithm achieves a competitive performance when compared with several state-of-the-art algorithms. The performance of the proposed method and the accuracy of distributed segmentation are affected by the degree of closeness between objects. 相似文献
15.
针对X3D虚拟场景的真实程度,从显示效果和文件大小角度研究烘焙技术在X3D虚拟场景中的应用,提出了在X3D虚拟场景中应用烘焙技术的操作方法,结合室内模型的地板烘焙实例阐述在建模、烘焙和导出X3D虚拟场景阶段的操作要点,验证了方法的可行性和有效性。 相似文献
16.
17.
提出了基于惯性导航系统与GPS定位系统根据自身优势,对载体在位置、速度和姿态角等各方面进行组合测试,使该系统能够对运行中的载体的方位信息进行精确地处理。给出了系统结构的设计方案。实验结果表明,该系统测量误差较小,能够满足实际使用要求。 相似文献
18.
C. G. Hebert S. J. R. Staton T. Q. Hudson S. J. Hart C. Lopez-Mariscal A. Terray 《Biomicrofluidics》2015,9(2)
The ability to confine flows and focus particle streams has become an integral component of the design of microfluidic systems for the analysis of a wide range of samples. Presented here is the implementation of a 3D microfluidic nozzle capable of both focusing particles as well as dynamically positioning those particles in selected flow lamina within the downstream analysis channel. Through the independent adjustment of the three sheath inlet flows, the nozzle controlled the size of a focused stream for 6, 10, and 15 μm polystyrene microparticles. Additional flow adjustment allowed the nozzle to dynamically position the focused particle stream to a specific area within the downstream channel. This unique ability provides additional capability and sample flexibility to the system. In order to gain insight into the fluidic behavior of the system, experimental conditions and results were duplicated within 4.75 μm using a COMSOL Multiphysics® model to elucidate the structure, direction, proportion, and fate of fluid lamina throughout the nozzle region. The COMSOL Multiphysics model showed that the position and distribution of particles upon entering the nozzle have negligible influence over its focusing ability, extending the experimental results into a wider range of particle sizes and system flow rates. These results are promising for the application of this design to allow for a relatively simple, fast, fully fluidically controlled nozzle for selective particle focusing and positioning for further particle analysis and sorting. 相似文献
19.
车载GPS接收机与PC机间串行通讯的实现 总被引：2，自引：0，他引：2
随着计算机、通信和信息技术的不断发展,全球定位系统作为一种精密的授时、测距、导航、定位系统,已经开始在军事、交通等领域得到越来越广泛的应用.本文介绍了GPS车裁定位导航系统中采用的GPS接收机与Pc机的串行通讯.GPs接收机采用NAME-0183标准数据格式,在遵循与PC机间通讯协议的基础上.利用VB中的MSComm控件实现了二者之间的串行通讯. 相似文献
20.
Gisela Pujol-Vazquez Leonardo Acho Saleh Mobayen Amelia Nápoles Vega Pérez 《Journal of The Franklin Institute》2018,355(10):4077-4096
The main objective of this paper is to drive a rotary inverted pendulum by following a desired navigation instruction. This navigation is commanded by the user through a new electromagnetic device which is allowed to perturb the pendulum from its upright position. This apparatus consists of an electronic magnetic driving circuit to introduce commands and realized via two operated magnetic coils. So, the external programmed magnetic perturbation can be seen as external commandments. Therefore, the control problem statement is solved via a modified regulation control implementation, to maintain the pendulum on its upright position and giving free manipulation of the base of the rotary inverted pendulum. Hence, by using the corresponding H∞-linear matrix inequality technique, a static state controller is designed and tested experimentally so supporting our findings. 相似文献