基于WLAN技术的室内定位方法研究

发布时间：2018-05-27 12:28

本文选题：室内定位 + TOA　；参考：《中国地质大学》2014年博士论文

【摘要】：随着以智能手机、笔记本电脑、平板电脑等为代表的智能移动设备的出现和发展,移动互联网得到了越来越广泛的应用,基于移动平台打造的工具软件和移动服务如雨后春笋般涌现,为各类行业用户和大众用户提供了丰富的服务。在移动互联网中,基于位置的服务是使用频率最高、应用最为广泛的服务之一,许多其它移动应用都直接或间接的使用到了LBS。借助于全球卫星定位系统,在户外等开放性场所,LBS已经能够为用户提供高精度、高稳定性的位置服务,其应用已渗入到各个行业领域和大众市场。然而在人类活动更多的室内场所,由于建筑物遮挡等问题,接收到的卫星信号往往已发生畸变,进而无法通过卫星定位系统准确地测量到目标在室内场所的准确位置。因此,研究适合室内环境的定位技术,开发满足行业用户和大众化应用需求的定位系统移动计算领域的研究热点之一。本文的研究工作是在近些年来无线局域网技术飞速发展和广泛普及的时代背景下,结合智能移动服务对定位导航技术、位置服务等新的需求而产生的。本文对这一基于时间测量的室内定位技术进行了较深入、系统的研究,并针对影响定位精度的关键因素加以归纳分析,并提出了相应的优化算法。通过与现有方法的比较分析,以及原型系统的实验验证,证明了本文的一系列优化算法具有一定的可行性。论文的主要研究内容和创新点归纳如下： (1)基于异步伪距差的室内定位方法的研究。本文提出了基于距离差的往返时间测量法,往返时间法(RTT)测量由目标终端主动发送的定位请求信号经过接入点处理返回的总的循环时间,以此避免对时钟同步的需求。同时采用伪距差法能够减少临近接入点因传播途中所受同源干扰造成的测量偏差。 (2)往返时间算法中系统处理延时的实时测定。传统的系统延时测定往往采用预先测值法来求得,在以后的定位使用中,沿用预先测量到的系统处理延时。这种方法的特点是,初步测量的延时在以后的使用中保持不变,无法实时改变。本文所述的方法将在每次信号传递到接入点端时开始计时,在信号传递回给目标终端时将计时数据打包,同其它信息一起返回,终端根据收到的实时测定结果来计算位置,具有较高的定位精度。 (3)以高斯“背景”模型的方式实现测量结果对动态环境的自适应。本文提出了一种“背景”建模的方法,解决测量数据变化后的自适应选取：将定位过程开始首段统计数据结果看作“背景”,“背景”为有效统计数据的合集。由于终端在室内场所的移动过程通常是缓慢的线性变化,当环境主动短时间变化,“背景”将保持不变,而当环境被动改变或长时间改变时,则将“新环境”(新的测试结果)线性的融入到“背景”中,形成新的“背景”数据,定位过程正是基于“背景”数据来测量终端的位置。 (4)研究基于定位高程坐标来优化水平定位结果的方法。目标大多数情况下在室内的活动处于离散的平面空间内,高度值趋于稳定,往往在该楼层高度值的1-2米之内。有基于此,本文提出了一种基于高度误差来优化水平定位结果的方法,通过对多次测量结果的统计数据,予以评估,进一步剔除高度偏差较大的测量结果,以达到优化测试数据的目的。 (5)研究以加权投票的方式实现定位信号接入点的实时选择。本文将研究一种加权投票方式来实现接入点的实时选取,其基本原理是选取信号传播途中,所受干扰相同的两个临近接入点,采用本文的距离差法计算两者信号传播的距离差,尽可能的保证信号传播途径中同源误差的去除。加权投票的方式主要用于接入点“临近”程度的判定。
[Abstract]:With the advent and development of smart mobile devices , such as smart phones , laptops , tablets , etc . , mobile Internet has been widely used . The location - based service is one of the most widely used services . In mobile Internet , LBS has been able to provide users with high - precision and high - stability services .

In this paper , the indoor positioning technology based on time measurement is researched deeply and systematically , and the key factors influencing the positioning accuracy are analyzed , and the corresponding optimization algorithm is put forward . Through the comparison and analysis of the existing methods and the experimental verification of the prototype system , it is proved that the series of optimization algorithms are feasible . The main research contents and the innovation points of the paper are summarized as follows :

A round - trip time measurement method based on distance difference is presented in this paper . The round - trip time method ( RTT ) is used to measure the total round - round time returned by the target terminal through the access point processing so as to avoid the need of clock synchronization .

The method is characterized in that the time delay of the preliminary measurement is kept unchanged in the later use and cannot be changed in real time . The method described in this paper will start timing when the signal is transmitted to the end of the access point , and then the time data is packaged and returned with other information when the signal is transmitted back to the target terminal , and the terminal calculates the position according to the received real - time measurement result , and has higher positioning accuracy .

In this paper , a method of " background " modeling is proposed to solve the adaptive selection of the dynamic environment . In this paper , a method of " background " modeling is proposed to solve the adaptive selection after data change . As a result , the moving process of the terminal in the indoor space is regarded as " background " and " background " is the combination of valid statistics .

( 4 ) The method of optimizing the horizontal positioning result based on the coordinate of the location is studied . In most cases , the activity in the room is in the discrete plane space , the height value tends to be stable , often within 1 - 2 meters of the height value of the floor . Based on this , this paper presents a method for optimizing the horizontal positioning result based on the height error .

( 5 ) The real - time selection of location signal access points is realized by means of weighted voting . In this paper , a weighted voting scheme is used to realize the real - time selection of access points . The basic principle is to select two adjacent access points which are the same as those in the way of signal propagation . The distance difference method is used to calculate the distance difference between the two signals , and the removal of homologous errors in the signal propagation path is ensured as much as possible . The way of weighted voting is mainly used for the determination of the proximity of access points .
【学位授予单位】：中国地质大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN925.93

【参考文献】