【作者】 刘晓文；

【导师】 关维国；

【作者基本信息】 辽宁工业大学 ， 通信与信息系统， 2012， 硕士

【摘要】 近年来,室内定位技术在大型场馆人员定位、仓储物流、矿山井下人员定位、应急救援等复杂环境下的人员与物品定位应用中发挥着极其重要的作用。基于无线传感器网络的室内定位技术凭借其传感器节点低成本、低功耗、易于组网数据传输等特性具有独特的优势。论文主要针对如何提高无线传感器网络室内定位精度进行了以下研究。首先,对无线传感器网络室内定位系统组成及节点组网协议进行了详细分析。分析研究了无线传感器网络中基于测距和非测距的定位原理,并对质心、DV-Hop算法的定位性能进行了仿真分析。其次,研究了RSSI-d衰减特性,对室内信号模型进行了分析,确定了算法所用室内信号路径损耗模型;针对RSSI方法测距定位误差较大的问题,提出了基于RSSI测距误差修正的加权质心定位算法。算法测距阶段采用基于最小二乘测距误差补偿方法对RSSI测距进行修正,以减小测距误差。定位阶段采用改进Euclidean加权质心定位算法,用信标节点对未知节点的不同影响力来确定加权因子,以提高定位精度。仿真表明,该算法精度较其它加权质心定位算法有了明显提高。最后,针对最小二乘法计算未知节点估计位置与实际位置偏差大的问题,提出了基于WLS与EKF的混合定位算法(CLA)。该算法在RSSI测距误差修正的基础上,首先采用加权最小二乘算法求得节点初步估计位置,将该初步估计位置作为扩展卡尔曼滤波的初始状态信息,然后采用扩展卡尔曼滤波对节点位置进行迭代求精。仿真表明,该算法具有较好的定位性能,在此基础上研究了优选信标节点参与扩展卡尔曼滤波迭代计算的最优排序方案,进一步提高了节点定位精度。更多还原

【Abstract】 In recent years, the indoor positioning technology plays an important role in the person localization, warehousing logistics, location for coal mine, emergency rescue work in complex personnel and items positioning circumstances. The indoor positioning technology based on wireless sensor networks has particular advantages by virtue of sensor node with low cost, low power consumption and convenience to data transmission. The paper focuses on the research as follows, which how to improve the indoor positioning accuracy of nodes. Firstly, the paper analyzed the composition of wireless sensor networks indoor positioning system and node networking protocol combined in detail. Then discussed wireless sensor network based on location principle of ranging and range-free, and analyzed positioning performance of centroid and DV-Hop algorithm.Secondly, the characteristic of RSSI-d attenuation was researched, and the indoor signal path loss model was determined by analyzing the indoor signal model. The algorithm of weighted centroid localization based on RSSI distance measurement error correction was proposed to solve the problem of RSSI ranging error. The least square error of the distance measurement compensation method was adopted in the algorithm to modify the distance measurement based RSSI that can reduce the error of distance measurement. The weighted centroid localization algorithm was employed in positioning stage; moreover, weighted factor was determined by the different influence of beacon nodes to unknown nodes to improve the positioning accuracy. Simulation results show that the accuracy of this algorithm is better than the other weighted centroid localization algorithms in performance.Finally, the combination localization algorithm based on WLS and EKF was improved according to the large estimates deviation calculated by least squares algorithm between unknown node position and actual position. First, the weighted least squares algorithm was used to calculated node preliminary estimated position based on the RSSI ranging error correction algorithm, and the node preliminary estimated position as the EKF initial status. Then, EKF was used to iteratively calculate node location estimates. The stimulation results show that the algorithm has good positioning performance. Based on the algorithm, the optimal ordering scheme of selected beacon node involved in EKF iterative calculation was researched to further improve the node location accuracy.更多还原