大规模有源RFID系统中标签快速检测算法的研究

发布时间：2019-05-18 04:01

【摘要】：射频识别技术(RFID)是从八十年代发展起来的自动识别的技术，是物联网技术中重要组成部分，可以应用于广泛地各个领域。现在己广泛应用于监控识别、智能交通，物流管理、工业、医学、防盗等各个领域，近几年物联网技术和应用的发展迅速，作为物联网关键核心技术的RFID识别技术己成为国内外研究的热点。 RFID技术的特性包括：非接触特性、识别高速运动的目标，多个远距离标签可同时识别，其中自身携带电池的有源RFID标签，能够支持远距离的信息通信，大数据量传输，较小的发射功率等优点，因此拥有非常广阔应用领域，特别应用于大型贵重物品或者危险物品监控和识别方面。针对有源标签组成RFID系统中，最大限度地减少识别时间，实现有源标签的低能量消耗，提高标签存在性检测效率，是标签检测算法值得研究的一个热点问题。本文简单介绍了本课题的研究背景和意义、RFID技术的系统工作原理等相关的知识，本文针对标签存在性问题进行了深入的研究，以提高标签检查效率，减少有源标签电量消耗为基础，主要从两个方面进行了改进：多阅读器系统中阅读器并行工作冲突问题和检测过程中标签能量消耗和效率问题。多阅读器并行工作时阅读器读取范围存在交叉碰撞问题，解决阅读器冲突碰撞问题一直是RFID技术研究的热点。本文基于粒子群算法和图着色算法相结合的分布式防冲突算法进行的改进，中心思想是服务器根据阅读器估计标签数量，实时的优化和更新阅读器时间段分配，新算法最大化利用阅读器网络的时隙，减少了系统时隙资源浪费，最终提高了系统识别的整体效率。 RFID系统中标签识别技术是RFID技术的关键技术。传统的自动识别技术通过收集所有标签标识号，并与系统数据库中存储的标签集合进行对比来判断标签存在性问题。但是这类方法识别效率很低，而且针对有源标签消耗自身电量偏高。针对以上问，本文在多阅读器并行基础上提出了一种新标签检测算法HPL，算法是基于帧时隙协议的改进，主要内容是阅读器发射查询帧时携带一个随机数Q，标签通过Q值选择一个时隙回复一个比特位，阅读器通过一个固定的轮询周期，完成一次识别过程，，根据回复信息形成了一个矩阵来判断标签的存在性。本文的算法经过理论分析和仿真证明，本文基于粒子群算法和图着色算法相结合的分布式防冲突算法进行的改进，减低了标签的识别时间，提高了系统吞吐率。和传统的基于标签标识号的检测算法相比较，本文提出的HPL（Hash polling Detection）算法在标签能量消耗上可降低一个数量级，同时缩短了算法的执行时间。和目前最好的迭代ID-free协议检测算法相比较，HPL算法在标签能量消耗上可降低三个数量级，并且也缩短了算法的执行时间。
[Abstract]:Radio frequency identification technology (RFID) is an automatic identification technology developed from 1980s. RFID is an important part of Internet of things technology and can be used in a wide range of fields. Now it has been widely used in monitoring and identification, intelligent transportation, logistics management, industry, medicine, anti-theft and other fields. In recent years, the technology and application of the Internet of things has developed rapidly. As the key core technology of the Internet of things, RFID identification technology has become a hot research topic at home and abroad. The characteristics of RFID technology include: non-contact characteristics, identification of high-speed moving targets, multiple remote tags can be identified at the same time, in which the active RFID tags carrying batteries can support long-distance information communication, large amount of data transmission, Because of the advantages of small transmission power, it has a very wide range of applications, especially in the monitoring and identification of large valuables or dangerous goods. Aiming at the RFID system composed of active tags, it is a hot issue that label detection algorithm is worth studying to minimize the recognition time, realize the low energy consumption of active tags and improve the efficiency of tag existence detection. This paper briefly introduces the research background and significance of this subject, the system working principle of RFID technology and so on. In this paper, the problem of label existence is deeply studied in order to improve the efficiency of label checking. On the basis of reducing the power consumption of active tags, it is mainly improved from two aspects: the parallel working conflict of readers in multi-reader system and the energy consumption and efficiency of tags in the process of detection. There is a cross-collision problem in the reader reading range when multiple readers work in parallel, and solving the reader collision problem has always been the focus of RFID technology research. In this paper, based on the improvement of distributed anti-collision algorithm based on particle swarm optimization algorithm and graph coloring algorithm, the central idea is that the server can optimize and update the time allocation of reader according to the number of tags estimated by the reader. The new algorithm maximizes the time slot of reader network, reduces the waste of system slot resources, and finally improves the overall efficiency of system recognition. Label recognition technology in RFID system is the key technology of RFID technology. The traditional automatic recognition technology judges the existence of tags by collecting all label identification numbers and comparing them with the tag sets stored in the system database. However, the recognition efficiency of this method is very low, and the power consumption of active tags is too high. In view of the above questions, this paper proposes a new label detection algorithm HPL, algorithm based on frame slot protocol on the basis of multi-reader parallelism. The main content is that the reader carries a random number Q when transmitting query frames. The tag selects a time slot to reply to a bit through the Q value, the reader completes a recognition process through a fixed polling cycle, and forms a matrix according to the reply information to judge the existence of the label. Through theoretical analysis and simulation, it is proved that the distributed anti-collision algorithm based on particle swarm optimization algorithm and graph coloring algorithm is improved in this paper, which reduces the recognition time of tags and improves the throughput of the system. Compared with the traditional detection algorithm based on label identification number, the HPL (Hash polling Detection) algorithm proposed in this paper can reduce the energy consumption of tags by an order of magnitude, and shorten the execution time of the algorithm at the same time. Compared with the best iterative ID-free protocol detection algorithm, HPL algorithm can reduce the label energy consumption by three orders of magnitude, and also shorten the execution time of the algorithm.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.44

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