An outdoor navigation system using GPS and inertial platform

The use of global positioning system (GPS) in outdoor localization is quite a common solution in large environments where no other reference is available and there are not so demanding positioning requirements. Of course, fine motion without the use of an expensive differential device is not an easy task, even now that available precision has been greatly improved as the military encoding has been removed. In this paper we present a localization algorithm based on Kalman filtering that tries to fuse information coming from an inexpensive single GPS with inertial data and map-based data. The algorithm is able to produce an estimated configuration for the robot that can be successfully fed back in a navigation system. Some experiments show difficulties and possible solutions of this sensor fusion problem     

基于卫星导航定位系统自适应抗干扰控制

在全球卫星导航系统抗干扰问题的研究中,自适应波束形成技术很好地解决了与信号不同来向的干扰的抑制问题。但对与信号同向的窄带干扰抑制程度不够,同时会滤除部分导航信号。针对以上问题,提出了一种改进的自适应波束干扰抑制算法。首先,通过级联IIR格型陷波器预测并抑制与信号同向的窄带干扰,然后,利用基于直接数据域自适应波束形成技术抑制剩余的宽带干扰。该改进算法能够有效的滤除窄带和宽带干扰,提升卫星导航系统的抗干扰性能,并在实际卫星通信应用中更具处理的实时性。最后,通过仿真实验证明了该算法的可行性。     

一种着陆导航系统电磁环境的评估方法

着陆导航系统是飞机安全飞行的一个重要保障,机场电磁环境的恶化严重影响到飞机着陆引导安全。以仪表着陆系统为例,分析着陆引导的基本原理,给出了着陆引导过程中飞机接收信号的数学模型,并基于此模型提出了一种机场电磁环境的评估方法,最后利用计算机仿真验证了该方法的有效性。     

An integrated mobile satellite broadcast, paging, communicationsand navigation system

The design of an integrated mobile satellite broadcast, paging, communications, and navigation system is described. Ku-band RadioSat ground stations will broadcast digital audio signals and data packets (including alphanumeric pages and group cells) to mobiles through a satellite to be launched in 1993. Each mobile radio will simultaneously receive L-band digital audio and data broadcasts from the satellite and L-band navigation broadcasts from the Global Positioning Systems (GPS) through a common omnidirectional mobile antenna and receiver front end. RadioSat mobile radios will use GPS broadcasts and differential corrections sent through the satellite to navigate with 2-m accuracy. With optional transmitters, RadioSat mobile radios can support two-way voice and data communications     

Land-vehicle navigation using GPS

The Global Positioning System (GPS) has made navigation systems practical for a number of land-vehicle navigation applications. Today, GPS-based navigation systems can be found in motor vehicles, farming and mining equipment, and a variety of other land-based vehicles (e.g., golf carts and mobile robots). Each of these applications is discussed and the reader is introduced to some of the issues involved with each one. One particular technical aspect of navigation for land vehicles is discussed. Specifically, the research discussed in this paper presents a quantitative examination of the impact that individual navigation sensors have on the perfomance of a land-vehicle navigation system. A range of navigation sensor performance levels and their influence on vehicle positioning accuracy are examined. Results show that, for a typical navigation system, positioning error is dominated by the accuracy of the position fixes provided by the GPS receiver when GPS position fixes are available and by the rate gyro's bias drift when GPS position fixes are not available. Furthermore, results show that the accuracy of the GPS position fixes has a significant impact on the relative contributions that each dead-reckoning navigation sensor error makes. The implications of these results for navigation system design and sensor design are discussed     

北斗导航系统的移动导航定位终端设计分析

卫星定位导航技术目前应用极为广泛,与人民生活息息相关,在手机定位、精准授时、汽车导航、智能交通、智能监控、智能家居、国际救援等等领域应用比较成熟。文章介绍了北斗导航系统的移动导航定位终端的分类和北斗定位基本原理、结构;设计了北斗导航系统的移动导航定位终端,给出了设计的结构、硬件电路以及操作系统。     

An identity-authentication system using fingerprints

Fingerprint verification is an important biometric technique for personal identification. We describe the design and implementation of a prototype automatic identity-authentication system that uses fingerprints to authenticate the identity of an individual. We have developed an improved minutiae-extraction algorithm that is faster and more accurate than our earlier algorithm (1995). An alignment-based minutiae-matching algorithm has been proposed. This algorithm is capable of finding the correspondences between input minutiae and the stored template without resorting to exhaustive search and has the ability to compensate adaptively for the nonlinear deformations and inexact transformations between an input and a template. To establish an objective assessment of our system, both the Michigan State University and the National Institute of Standards and Technology NIST 9 fingerprint data bases have been used to estimate the performance numbers. The experimental results reveal that our system can achieve a good performance on these data bases. We also have demonstrated that our system satisfies the response-time requirement. A complete authentication procedure, on average, takes about 1.4 seconds on a Sun ULTRA I workstation (it is expected to run as fast or faster on a 200 HMz Pentium)     

利用电磁导航的AGV设计

随着物流系统的迅速发展,AGV的应用范围也在不断扩展,为了满足用户功能、价格、质量方面需求的AGV系统,研究设计了一种基于电磁导航的无人驾驶小车系统方案。通过实际硬件实验,系统能够达到预期设计要求,能够广泛运用于工业、军事、交通运输、电子等领域,具有良好的环境适应能力,很强的抗干扰能力和目标识别能力。     

A pedestrian navigation system using a map-based angular motion model for indoor and outdoor environments

By incorporating known floor-plans in sequential Bayesian positioning estimators, such as particle filters, long-term positioning accuracy can be achieved as long as the map is sufficiently accurate and the environment sufficiently constrains pedestrians’ motion. Instead of using binary decisions to eliminate particles when crossing a wall, map-based angular probability density functions (PDFs) are used in this article that are capable of weighting the possible headings of the pedestrian according to local infrastructure. In addition, we will include outdoor maps by processing satellite images of the region. We will show that the angular PDFs will help to obtain better performance in critical multi-modal navigation scenarios and in the outdoor area when including maps.     

非基于影像的计算机导航系统在骨关节手术中的应用

非基于影像的计算机导航系统在骨关节手术中,没有采用患者任何术前或是术中的医学影像,而是通过导航器械实时获取手术区域关节等相关位置的三维数据信息,经过计算机系统中导航软件的处理,形成患者关节的三维模型,指导术者按一定的工作流程对手术进行实施的过程。文中主要列举了两种以不同建模方式形成的非基于影像的计算机导航系统,从它们的硬件组成、工作原理、适用证等方面进行了逐一分析。     

ILONA: indoor localization and navigation system

Indoor positioning is a hot topic these days and there is a growing need for it in public buildings such as airports, hospitals, universities or shopping malls. Indoor positioning systems should be accurate, easily available for the users, with low installation and maintenance cost, which makes development challenging. Existing systems are based on various technologies such as ultrasonic, RFID, WiFi or light encoding. Moreover, these systems are tailored to a given environment and usually rely on a single technology. This paper presents the indoor localization and navigation (ILONA) System, a flexible hybrid indoor positioning and navigation framework. The ILONA System was not designed to be a solution for a single indoor positioning task but to be a standard core component of various systems. The ILONA System provides easily available positioning and navigation services for the end users. The system can manage data from the most commonly available sensors of modern smart phones. Thus, the ILONA System can perform positioning based on various technologies. ILONA System can be established at low cost because it only requires a connection between the server and the clients and WLAN is usually available. Hence, the presented ILONA System provides a widely available, hybrid indoor positioning framework at low cost to the developers of other indoor positioning solutions.     

北斗/罗兰组合导航系统中伪距导航定位解算新算法研究

为提高北斗／罗兰组合导航系统伪距导航定位解算的精度和改善对动态目标的实时跟踪,本文提出了一种新方法,采用镜像映射法解具有病态的矛盾方程组以提高精度,以及将伪距导航定位解算方程模型转换为具有贯序输入输出数据的系统辨识模型,然后用递推最小二乘法,对所求的北斗／罗兰组合导航系统伪距导航定位信息一接收机的三维位置参数和时钟误差参数进行动态快速实时估计。     

惯性/卫星导航系统实际导航性能评估算法

针对惯性/卫星组合导航进行实际导航性能(Actual Navigation Performance,ANP)评估,是保证飞机所需导航性能(Required Navigation Performance,RNP)及航空运行安全的关键.提出了惯性/卫星组合导航系统实际导航性能评估算法,从卡尔曼滤波器位置协方差矩阵开展分析,...     

用于组合导航系统的三轴地磁导航传感器设计

文章针对仿生偏振光/地磁/惯导多源信息组合导航系统中的地磁导航需求,设计了一种三轴地磁导航传感器。介绍了应用背景、设计需求与实现方法,进行了系统的误差分析,并针对不同误差来源,进行了标定测量与补偿,实现了三轴姿态角的动态测量,为多信息源融合下的导航系统提供了一种获取地磁导航信息的有效手段。     

车载导航系统终端的研究

将GPS定位技术应用于气车,与现有定位技术组合起来共同完成定位监控任务,将大大提高定位准确性及安全性,同时能够降低资金投入,具有很广阔的发展前景。随着全国各省市高速公路路网的建设与完善,对交通管理信息化的要求越来越高。本文提出了如何实现基于ARM的车载导航系统,本设计采用瑞士u-blox公司的NE0-5Q的主芯片接收GPS卫星信号,通过三星公司的S3C2440芯片对接收到的数据进行处理,并对如何编写GPS模块的驱动程序进行了比较详细的讲解。把编写好的GPS驱动程序加载到Linux内核中去以供GPS的应用程序使用。本文介绍了系统的总体架构,然后重点介绍了对GPS模块的驱动程序和应用程序的编写。     

耐高温卫星导航天线

设计了一种陶瓷基底的右旋圆极化微带天线,能够满足高温环境下卫星导航系统的应用.天线设计特点有以下四点:天线外形具有低轮廓特性, 适合高速运动飞行器表面的贴装; 采用钛合金材料和高温陶瓷材料, 能够在400 ℃高温环境下正常工作, 具有优异的耐热性能; 加工装配流程均无焊接工艺, 确保天线组件的电连接在高温冲击下的可靠性; 采用中心短路销钉设计, 减少同轴馈针的感抗, 获得优异的阻抗匹配特性.通过仿真优化和实际测试, 验证了该天线性能优异, 满足高温环境下的卫星导航系统的使用要求.     

基于Android的校园导航系统的设计与实现

为使大学生能够快速熟悉校园环境,迅速适应大学生活,开发了基于Android的校园导航系统.该系统以新疆大学本部校园为例,在研究校园用户对地图服务需求的基础上提出了相应的功能.开发中充分利用了百度地图API接口,实现了校内地点搜索、位置提醒等功能,并利用FLOYD算法实现了路径规划.     

汽车导航市场攻略

汽车导航类电子产品近年在全球市场上兴起，具有广阔的市场发展前景，引起了全球电子业界的重视，争相进军这一市场。目前世界上发达国家的汽车导航系统产品主要有三大类：①专用PC(CarPC)汽车导航专用系统，该系统技术最先进，但价格昂贵，一般要2000~3600美元，主要应用于宝马等豪华汽车的导航。②PDA汽车导航系统，该系统以掌上电脑为平台，集成了GPS、GIS等导航系统，辅以专业的导航软件，成为集成化导航系统。掌上电脑汽车导航类产品在国内的发展时间虽然仅2年左右，但由于其价格低廉，仅为350~500美元，因此，产品上市后十分抢…     

印度卫星导航系统概述

详细介绍了印度GPS辅助GEO增强导航系统(GAGAN)和印度区域导航卫星系统(IRNSS系统)的星座组成、信号体制、导航电文、地面系统以及发展现状,分析了印度卫星导航系统的发展计划。相关内容对我国卫星导航系统的发展建设及应用具有重要的参考意义。     

拖轮智能航行系统的设计与实现

随着船舶制造业的发展,智能船舶设计和应用被提上日程,文章参照《智能船舶规范》的要求,结合港作拖轮的航行和作业特点,探讨性地设计了针对拖轮的智能航行系统,具有基于电子海图的多目标航迹多模式规划和避障功能、近距避碰预警功能、岸基作业管理及油耗统计功能,经与主管部门沟通和产品实际应用,初步满足了规范要求。