基于UWB的室内高精度定位方法研究与应用

发布时间：2019-05-28 03:50

【摘要】：伴随着移动通信和无线传感器网络(WSN)近几年的不断发展,在室内环境下基于位置的服务(LBS)越来越受到人们关注。传统的室内定位如红外线、RFID、蓝牙等技术,在系统成本、定位精度、复杂度、稳定性等方面不能满足用户需求。在这样的背景下,超宽带(Ultra Wide Band,UWB)定位技术引起了人们的重视。UWB技术具有高通信能力、抗多路径、穿透能力强、高时间分辨率等优点,因此是室内高精度定位的较好选择。本文围绕着如何提高UWB室内定位精度展开讨论与研究,主要工作包括：分析了常用的室内定位技术的优缺点和对UWB使用各种技术的可行性进行了分析,在理论上论证了适合UWB定位的技术,研究分析表明：基于接收信号强度(RSS)的定位技术易受外界环境干扰定位精度较差；基于信号到达角度(AOA)的定位技术需要天线阵列且不适合在多路径密集的环境下应用;基于信号到达时间的定位技术能够充分利用UWB信号的穿透能力强、抗多路径和高时间分辨率等优点,具有很高的定位精度。通过对UWB的测距方法进行分析,确定基于到达时间差(TDOA)的测距方式适合UWB,并实验测试了不同室内环境下UWB的测距精度和分析了多路径、系统偏差、比例误差、异常值、非视距(NLOS)等对测距精度的影响。测试结果表明：在室内LOS下,多路径对UWB测距精度影响很小；剔除测距过程中产生的异常值能够提高测距精度3mm左右。在室内NLOS下,测距精度明显降低,分析发现影响测距精度的主要因素是NLOS。针对测距中的NLOS误差问题,分析了常用的鉴别方法。然后重点研究了如何对测距中的NLOS误差进行抑制和粗差剔除,提出了基于自回归的卡尔曼滤波法对UWB测距进行预处理。实验表明,采用自回归卡尔曼滤波法对UWB测距进行预处理后再定位,能有效提高定位精度,定位精度可达亚分米级。将UWB定位系统应用到火灾现场救援中。通过模拟实验表明：设计的室内定位系统能够对火灾现场消防员位置进行精确定位与跟踪。
[Abstract]:With the continuous development of mobile communication and wireless sensor network (WSN) in recent years, location-based service (LBS) has attracted more and more attention in indoor environment. Traditional indoor positioning such as infrared, RFID, Bluetooth and other technologies can not meet the needs of users in terms of system cost, positioning accuracy, complexity, stability and so on. In this context, ultra-broadband (Ultra Wide Band,UWB) positioning technology has attracted people's attention. UWB technology has many advantages, such as high communication ability, anti-multi-path, strong penetration ability, high time resolution and so on. Therefore, it is a good choice for indoor high precision positioning. This paper discusses and studies how to improve the accuracy of UWB indoor positioning. The main work includes: analyzing the advantages and disadvantages of the commonly used indoor positioning technology and the feasibility of using various technologies in UWB. The technology suitable for UWB positioning is demonstrated theoretically. The research and analysis show that the positioning technology based on received signal strength (RSS) is easy to be interfered with by the external environment. The positioning technology based on signal arrival angle (AOA) needs antenna array and is not suitable for application in multi-path dense environment. The positioning technology based on signal arrival time can make full use of the advantages of UWB signal, such as strong penetration ability, anti-multi-path and high time resolution, and has high positioning accuracy. Through the analysis of the ranging method of UWB, the ranging method based on arrival time difference (TDOA) is determined to be suitable for UWB, and the ranging accuracy of UWB in different indoor environments is tested, and the multi-path, system deviation, proportional error and abnormal value are analyzed. The influence of non-line-of-sight (NLOS) on ranging accuracy. The test results show that the multi-path has little effect on the ranging accuracy of UWB under indoor LOS, and the outliers produced in the process of removing ranging can improve the ranging accuracy of 3mm. Under indoor NLOS, the ranging accuracy is obviously reduced. It is found that the main factor affecting the ranging accuracy is NLOS.. Aiming at the problem of NLOS error in ranging, the commonly used identification methods are analyzed. Then, how to suppress the NLOS error and eliminate the gross error in ranging is studied, and a Kalman filter method based on autoregression is proposed to preprocess UWB ranging. The experimental results show that the autoregression Kalman filter method can effectively improve the positioning accuracy and reach the sub-decimeter level after preprocessing the UWB ranging. The UWB positioning system is applied to the fire scene rescue. The simulation results show that the designed indoor positioning system can accurately locate and track the position of firefighters in the fire scene.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN925

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