室内定位技术研究.docx

摘要
随着无线定位技术的迅速发展,基于定位的服务(LBS)也逐渐普及到各个领域,例如航海导航车载定位以及人员跟踪等。尽管基于GPS技术的室外定位已经达到了很高的定位精度,但是由于GPS信号无法达到室内的特性,在GPS不适用于室内环境的条件下,室内定位面临着各种技术难题和挑战,所以它也成为当前研究和关注的热点。现有的室内定位技术主要有红外线定位、超声波定位、RFID射频识别定位以及WIFI定位等。其中,基于WIFI的定位近几年来倍受人们的关注。
Wifi定位有多种算法,本文采用最近点搜索法来实现定位,这个算法是先采集一定数量的样点,计算出它们到每个AP点的信号损耗,将这些数据输入进数据库,然后通过自身位置到各个AP点之间的信号损耗和数据库中各个样点到每个AP点的信号损耗作对比,最后定位出实际位置。
本算法是通过MATLAB仿真来实现的,仿真了在100m*100m范围内,取5个AP点,在步长和实际位置不同的情况下的定位结果。其中步长分别取了1m到10m,实际位置随机取了5个点。最后从仿真结果可以看出步长的选取与实际位置的坐标存在关系。当实际位置的横纵坐标除以步长取的余数越小,定位的结果就会越准确。当余数为0时,定位的结果就是实际位置。
关键词: wifi 室内定位技术最近点搜索法 MATLAB仿真
Abstract
With the rapid development of wireless location technology, location-based services (LBS) also gradually spread to all fields, such as navigation vehicle positioning and tracking of personnel. Although outdoor location based on GPS technology has reached a very high positioning accuracy, but because of the GPS signal can not meet the characteristics of indoor, GPS does not apply to indoor environment, indoor location is facing kinds of technical problems and challenges, so it has e the focus of research and attention. The existing indoor positioning technology mainly has the orientation of infrared, ultrasonic, RFID radio frequency identification, and WIFI positioning, etc. Among them, based on WIFI positioning much attention in recent years.
Wifi positioning has a variety of algorithms, the paper uses the closest point search method to implement the localization, the algorithm is to collect a certain quantity of sample, calculate loss of signal to each ap point, the input data into the database, and then through their own position to between each ap signal loss and database of each sample pared to each ap signal loss, finally locates the actual location.
The algorithm is implemented by MATLAB, within 100 * 100, 5 AP points, in the step length and actual location positioning result of different situations. One step took 1 to 10, respectively, the actual location of random took five points. The select