Novel indoor positioning system based on ultra-wide bandwidth

To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is proposed.First,we illustrate a distance measuring method between two UWB devices.Then,a Taylor series expansion algorithm is developed to detect coordinates of the mobile node using the location of anchor nodes and the distance between them.Simulation results show that the observation error under our strategy is within 15 cm,which is superior to existing algorithms.The final experimental data in the hardware system mainly composed of STM32 and DW1000 also confirms the performance of the proposed scheme.

Mobile Robot Positioning and Tracking Based on Ultra-wideband Technology

To solve the precision self-positioning problem for mobile robot,a positioning program based on ultra-wideband technology was proposed. Ultra-wideband pulse has very high bandwidth; ranging accuracy can achieve centimeter-level theoretically. The mobile robot obtained the distance to the reference node by sending ultra-wideband pulse. According to the geometric relations among the references and the robot,establish equations to calculate the position coordinates. Then Kalman filter algorithm was applied for mobile robot tracking. Simulation results show that robot positioning and tracking based on ultra-wideband technology can achieve indoor and outdoor seamless docking.

Compact Coplanar Epsilon-Negative Antenna with Ultra-Wide Band Character

In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feeding antenna, and thus the via.free structure is employed to realize the ENG unit cell, which is convenient to tune the frequency of zeroth.order resonance(ZOR) and extends the ZOR bandwidth. The high.order resonant frequencies are achieved and mainly determined by the separate slots that are located between the radiating patch and the ground plane. Adding the left.handed inductance between the radiating patch and ground has slight impact on the high.order resonant frequencies, and then the ultra.wide band is achieved by merging the ZOR bandwidth with the high.order resonant bandwidths. The ground plane primarily works as a matching network for the proposed antenna. Although it generates a low.frequency resonance, the performance is undesirable due to the impedance mismatching. The measured results show that the reflection coefficient, |S11| <.10 d B, is in a wide frequency range from 5.25 to 13 GHz, which covers the upper operation band of UWB communication. Also, the antenna contains relatively stable gains and omni.directional radiation patterns.

Numerical simulation of the coupling of ultra-wide band electromagnetic pulse into landmine by aperture

The modern landmine＇s electronic fuse is susceptible to strong interference or can even be damaged by the ultra-wide band electromagnetic pulse（UWB-EMP）. The finite-difference time-domain（FDTD） method in lossy media with cylindrical coordinates is used to study the interactions of the UWB-EMP with the landmine. First, the coupling of UWB-EMP into the landmine shielding shell through an aperture is numerically simulated. Second, the coupled electromagnetic field of mine shells made of different shielding materials and with apertures of different sizes is plotted. Third, the aperture coupling laws of UWB-EMP into shells are analyzed and categorized. Such an algorithm is capable of effectively preventing ladder similar errors, and consequently improving the calculation precision, and in addition to adopting the message passing interface（MPI） parallel method to divide the total calculating range into more sub-ranges, the overall calculating efficiency is greatly increased. These calculations are surely a constructive reference for modern landmine design against electromagnetic damage.

Designing a Carbon Nanotube Field-Effect Transistor with High Transition Frequency for Ultra-Wideband Application

Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.

Evaluation of System Performance of Ultra-Wide Band Jointing in MC Signaling in Correlated Environments

The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.

Angular insensitive nonreciprocal ultrawide band absorption in plasma-embedded photonic crystals designed with improved particle swarm optimization algorithm

Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.

番茄苗期叶位色素含量高光谱检测及可视化研究

叶片色素含量是表征作物栽培基质营养元素和生理状态的重要指标;快速、精准获取色素含量及叶位分布规律是设施农业水肥精准化管理的基础。以番茄苗期不同叶位叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素(Chll)和类胡萝卜素(Caro)为研究指标,用营养液配制10个氮素浓度;根据叶片位置摘取1710片(285个样本)用于可见光-近红外高光谱采集;运用卷积平滑(S-G)、标准正态变量变换(SNV)和多元散射校正(MSC)对光谱数据预处理。首先采用竞争自适应加权算法(CARS)对特征波段“粗”提取,然后利用迭代和保留信息变量算法(IRIV)判断“粗”提取波段的重要性,并对强弱波段组逆向消除“精”提取最优波段集合,建立偏最小二乘回归(PLSR)模型。结果表明:(1)营养液氮素浓度为302.84 mg·L^(-1),叶片色素含量最大,且高浓度的抑制作用高于低浓度,叶位色素含量呈上叶位>中叶位>低叶位分布规律;(2)采用CARS-IRIV-PLSR算法“粗-精”特征波段筛选策略分别对Chla、Chlb、Chll和Caro提取了4、4、10和11条特征波段,其Rp为0.7722、0.7321、0.8471和0.8587;(3)结合最优模型色素定量反演图像可视化表达,Chla、Chlb和Chll分布规律一致,而Caro与Chll分布规律相反,该结论与植物生理特征和测定结果相吻合。采用高光谱成像技术能够实现对叶片色素含量进行无损检测及可视化表达,为设施农业植物叶片色素分布、养分亏缺和施肥决策等提供数据支撑和理论依据。

北斗三号带状CORS系统基准站布设距离研究

针对传统的CORS系统在高速公路等带状区域场景下存在的定位性能不足问题,尝试通过构建单站RTK和多站VRS结合的带状CORS系统从而提升定位性能,并实地采集多组不同基线长度的北斗三频观测数据,测试在满足平面2 cm、高程3 cm的最大定位误差前提下,该种CORS服务模式下基站的合理布设距离。实验结果表明,在开阔、轻微遮挡和中度遮挡环境下,满足该定位精度的基线长度分别可以达到30 km、19.7 km、15 km,而对于更长的基线,其定位精度及模糊度固定成功率均明显下降,不能保证定位的可靠性。

基于KF-LSTM的UWB室内定位算法

作为一种新型无线定位技术,超宽带在室内定位领域中引起了广泛关注。为了提高超宽带的定位精度,本文结合卡尔曼滤波和LSTM网络的优势,提出一种融合卡尔曼滤波的长短期记忆神经网络(KF-LSTM)算法。首先,通过卡尔曼滤波对UWB时序数据进行处理,削弱数据中的高斯白噪声;然后,将数据投入LSTM网络中进行训练,利用LSTM网络处理时序特征的优势处理非高斯噪声,进而得到更准确的标签位置。实测数据表明,与BP、KF-BP和LSTM网络算法相比,KF-LSTM算法的平均定位精度分别提高了70.21%、37.28%和38.23%,且KF-LSTM算法表现更稳定。

信号干扰下的超宽带精确定位问题研究

针对在室内应用超宽带UWB(Ultra Wide Band)定位技术时,需要建立高效精确的三维坐标定位系统以克服信号干扰问题,应用机器学习方法对其进行了研究。首先使用多种统计分析模型清理无效或误差测量值;然后将TOF(Time Of Flight)算法的先验知识与神经网络、XGBoost(eXterme Gradient Boosting)算法相结合,提出了神经XGB(Exterme Gradient Boosting)三维定位系统,该系统可通过“正常数据”和“异常数据”(受干扰)以及4个锚点的坐标精准预测靶点的坐标值,能使误差在二维平面降至5.08 cm,在三维空间降至8.03 cm;同时建立了判断数据是否受干扰的神经网络分类模型,精确率为0.88;最后通过结合上述系统,得到了连续且规律的运动轨迹,证明了系统的有效性与鲁棒性。

一种复杂环境下UWB测距误差预测方法

针对复杂室内环境中,多径干扰和视距遮挡影响室内定位精度的问题,提出一种复杂环境下UWB测距误差的预测方法:根据超宽带(UWB)室内定位方法抗干扰能力强、定位精度高的特点,从理论上分析影响超宽带信号测距精度的因素;然后通过模型量化分析每种影响因素对测距误差的影响程度,改进以往通过信道脉冲响应特征分析单一的视距遮挡参数来提高定位精度的补偿算法;最后从数据挖掘和机器学习的角度出发,将多径效应、视距遮挡、标签与基站的距离、标签移动速度、标签与基站天线俯仰角以及气象因素(温度、湿度、压强)等对测距精度造成影响的重要因素作为特征进行分类和归类,并使用梯度提升决策树模型对数据集进行训练和预测。实验结果表明,该模型可以根据当前状态下的组合特征值估计出测距误差值,将当前预测的误差值补偿到测量值上,可以有效提高超宽带室内定位的精度。

基于模态分析的宽频带振荡区域定位研究

伴随化石能源的枯竭和我国能源转型战略的推进,新能源发电系统上网电量不断增加。电力系统“双高”特性日益显著,系统运行面临更为复杂的挑战,其中电力电子装置引发的宽频带振荡备受关注。因此,针对新能源系统宽频带振荡产生的机理,提出一种基于模态分析的宽频带振荡区域定位方法,用于新能源系统振荡频率和振荡区域定位。根据逆变器、线路阻抗和电网阻抗等系统参数,建立不同型号逆变器并联系统的高阶导纳矩阵。对矩阵进行等效变换,通过绘制模态阻抗随频率变化的曲线,得到系统可能的谐振频率。通过节点参与因子计算,定位振荡的区域。通过仿真验证,模态分析方法可以实现宽频谐振的精准频率定位和区域定位,可为新能源场站接入评估和事故定位提供依据。

一种基于超宽带基站设置虚拟围栏的手术室移动医疗设备定位方法

针对医院手术室各手术间存在大量移动医疗设备交叉使用难以实时定位管控的难题,该研究提出一种时效性高、易于部署且定位准确度相对较高的基于UWB技术的实时定位方法。该方法包括对超宽带(UWB)基站的拓扑布局,在手术室走廊、设备间内应用改进的飞行时间(TOF)双边双向测距定位法定位,在手术间入口设置虚拟围栏判断设备是否进入。经试验,该方法可大幅度降低UWB基站布置数量,具备厘米级定位精度和较高识别率,可替代传统的手术室移动医疗设备人工定位管控方式。

基于概率误差的三维室内定位系统最优布站方法

随着智能化、自动化技术的不断发展,室内定位技术的应用场景日益广泛,如何提高室内定位系统的精度和可靠性一直是研究热点。对基站布局进行优化,提升系统整体的定位精度是现有的室内定位系统优化方法之一。对于该方法,现有的研究普遍选择采用其他相似领域的已有方法,主要的两种方法中用于评价卫星共轭的精度稀释因子忽略了基站与标签的距离;作为导弹、惯导系统中落点精度评价因子的概率误差方法没有考虑基站几何结构的影响。对此,提出了一种基于精度稀释因子和概率误差方法的精度评价模型,用于推导三维室内定位系统的最优基站布局,该模型同时考虑了距离和几何结构对室内定位精度的影响,可以很好地应用于室内定位的领域。所提方法在程序模拟和实际定位实验中均取得了优异的效果。在程序模拟中,最优基站布局系统的定位误差均值相比传统四顶角定位系统降低了约14.38%,在实际定位实验中,最优布局的定位精度和效果都得到了显著提升。实验结果验证了精度评价模型的准确性与实用性。所提出的最优基站布局方法在三维室内定位领域具有很高的应用价值和普适性,能够有效提高室内定位系统的精度和效果。

基于UWB定位技术的煤矿机械装备防碰撞系统研究

随着煤矿机械装备的广泛应用,机械装备的防碰撞已经成为煤炭行业重要的研究课题。文章主要研究了基于超宽带(Ultra Wide Band,UWB)定位技术的煤矿机械装备防碰撞系统,通过开发定位算法、防碰撞算法、数据处理与分析等功能模块,实现系统的实时监控与报警功能。实验表明,该系统能够有效避免机械装备之间发生碰撞,进而提升煤矿生产的安全性。

一种基于信号特征分析和机器学习技术的900 MHz频段干扰自动定位方法

随着无线电通信的迅速发展,频谱资源日益紧张,各种干扰问题也越来越严重。其中,900 M Hz频段的干扰问题尤为突出。该文提出了一种基于信号特征分析和机器学习技术的900 MHz频段干扰自动定位方法,通过对干扰信号的频谱、时域、调制等特征进行分析,建立干扰信号特征库,并利用机器学习算法对信号进行分类和定位。实验结果表明,该文提出的方法具有较高的干扰定位准确率和稳定性,能够有效地提高频谱资源利用效率的闭环。

升空平台相对测量误差对定位精度的影响及定位算法

针对精准协同任务下的分布式升空平台高精度相对定位需求,基于超宽带(UWB)测距传感器研究了相对测距与定位模型,对UWB模块在非理想情况下存在的误差因素进行了推导分析,包括天线相位中心误差、测距刷新率和悬停稳定度。在此基础上对噪声成分进行了实测分析与滤波处理:通过Allan方差辨识UWB传感器噪声,并将有色噪声模型及估计参数引入到定位算法量测更新中,通过改进扩展卡尔曼滤波算法实现了分布式升空平台相对定位。仿真结果表明:在相对测量噪声服从非高斯分布情况下,所提算法相较于传统算法位置估计精度提高约23.43%。与传统算法相比,所提算法可减少测量色噪声影响,提高卫星导航拒止环境下的相对定位精度。

团体积极心理护理联合弹力带抗阻训练在慢性心力衰竭患者护理中的应用分析

目的探讨团体积极心理学护理联合弹力带抗阻训练在慢性心力衰竭(Chronic Heart Failure,CHF)患者中的应用效果。方法单纯随机选取2021年11月—2023年10月湄潭县中西医结合医院收治的120例CHF患者作为研究对象,按随机数表法分为两组,每组60例。对照组采取弹力带抗阻训练,观察组加用团体积极心理学护理。对比两组训练依从性、心理状态及生活质量评分。结果观察组训练依从性为96.67%,高于对照组的85.00%,差异有统计学意义(χ^(2)=4.904,P=0.027);观察组干预后焦虑自评量表、抑郁自评量表、明尼苏达心力衰竭生命质量量表评分低于对照组,差异有统计学意义(P均<0.05)。结论团体积极心理学护理联合弹力带抗阻训练能改善CHF患者心理状态、训练依从性,提高生活质量。

基于WSN+UWB的室内人员定位系统设计

随着社会发展,家长对幼儿安全越来越重视,幼儿园环境安全与否直接关系到儿童的健康及生命。为保障园区内幼儿状况及安全,文章提出了一种室内人员定位系统设计,该系统在满足基本定位需求的同时,采用了超宽带(Ultra Wide Band,UWB)技术,具有穿透性强、抗干扰和功耗低等优势,其性能表现已超过蓝牙和Wi-Fi,并以UWB技术作为主要技术依据,将无线传感网络(Wireless Sensor Network,WSN)技术与UWB技术相结合,设计了一款智能化的人员看护及定位系统,测试结果证明了该系统设计可满足园区内人员监测及定位警报的需求。