基于主元分析的多联式空调系统传感器故障检测和诊断

作为多元数据分析方法之一,主元分析(PCA)被广泛运用于诊断制冷空调系统的传感器故障。本文首先结合热平衡原理以及多联机运行的控制逻辑,筛选系统中常用的18个传感器变量建立多联机(VRF)传感器的故障分析(FDD)模型。然后结合主元分析的算法原理,给出以Q统计量和Q贡献率为检验标准的传感器故障检测与诊断流程。接着用实测数据进行验证工作,引入不同类型和程度的传感器故障,分析得到不同故障条件下的故障检测和诊断特性。结果表明,总体上,主元分析应用于多联机传感器故障检测与诊断过程是可靠的。其具体特征表现为：不同类型的传感器在不同故障类型及程度条件下,故障检测效果差异明显;在小偏差故障条件下,基于主元分析的传感器故障检测方法的故障检测效率较低,并且针对个别传感器而言,其整体故障检测效率偏低。鉴于故障诊断是基于故障检测的结果,因此上述故障检测方法在FDD过程中将起到重要的作用。     

主元分析用于多联式空调系统传感器故障检测和诊断

作为多元数据分析方法之一,主元分析(PCA)被广泛运用于诊断制冷空调系统的传感器故障。本文首先结合热平衡原理以及多联机运行的控制逻辑,筛选系统中常用的18个传感器变量,建立多联机(VRF)传感器的故障分析(FDD)模型。然后结合主元分析的算法原理,给出以Q统计量和Q贡献率为检验标准的传感器故障检测与诊断流程。利用实测数据验证工作,引入不同类型和程度的传感器故障,分析得到不同故障条件下的故障检测和诊断特性。结果表明:总体上,主元分析应用于多联机传感器故障检测与诊断过程是可靠的。具体特征表现为:不同类型的传感器在不同故障类型及程度条件下,故障检测效果差异明显;在小偏差故障条件下,基于主元分析的传感器故障检测方法的故障检测效率较低,并且针对个别传感器而言,其整体故障检测效率偏低。鉴于故障诊断是基于故障检测的结果,因此上述故障检测方法在FDD过程中将起到重要的作用。     

基于CAFOA-GRNN的包装机热封温度传感器的故障检测

目的 为了实现自动包装机热封工艺中温度传感器的故障实时故障检测。方法 使用广义回归神经网络（General Regression Neural Network, GRNN）构建了热封温度传感器状态自动检测网络,再采用混沌加速果蝇优化算法（Chaos Accelerated Fruit Fly Optimization Algorithm , CAFOA）进行广义回归神经网络的学习因子优化选取,求解出最优学习因子。通过建立CAFOA-GRNN自动检测模型,再结合统计学中置信区间的方法,对故障进行诊断分类。结果 在传感器故障实验中,将理想故障函数与历史运行数据叠加,产生故障数据集,并将其用于验证建立的模型,获得了较好的检测效果,准确率较高。结论 该方法实现了传感器故障的实时检测,可以用于提高生产的可靠性,具有一定的工程实用价值。     

基于自适应滤波器的无人水下机器人传感器故障诊断研究

采用自适应滤波器FIR(Finite Impulse Response Filter)对无人水下机器人进行在线自适应建模,并利用LMS(least-mean-square)算法在线调节滤波器的权系数,通过对滤波器权系数和误差信号平方的分析,可实时检测出传感器的故障。针对OUTLAND1000无人水下机器人方向传感器,应用该方法对传感器的故障进行检测,实验结果表明所提故障检测方法准确可靠、并具有较好的实时性。     

基于混合信息增量矩阵的传感器网络故障自检测算法

针对无线传感器网络(WSNs,wireless sensor networks)故障检测过程中邻居协作导致额外的通信和计算负载的问题,提出一种用于无线传感器网络中的混合信息增量矩阵的故障自检测算法。该算法不需要邻居协作,通过对现有的基于局部信息增量矩阵的故障检测方法进行改进,以实现更好的故障检测能力。仿真结果表明,与局部信息增量矩阵算法相比,本算法具有更好的故障检测性能和鲁棒性,更适合于无线传感器网络的应用环境。     

基于小波算法的摆式列车倾摆指令实时提取

由于摆式列车线路检测系统测得的线路超高时变率信号是平稳的且含有幅度大、频带宽的噪声 ,难以用常规的滤波方法得到摆式列车实时倾摆指令。本文介绍了多分辨率分析的基本原理及快速算法 ,讨论了基函数的选取 (构造 )原则。根据超高时变率信号的特征 ,合理选择基函数 ,提出了一种对流式数据的实时滤波算法 ,通过对仿真和线路试验实测数据的处理与常规滤波方法进行了比较。结果表明 ,该算法能更快地实时提取摆式列车倾摆指令。     

摆式列车倾摆控制信号测量与传感器的选型

在时域和频域中 ,将能够测量摆式列车倾摆信号的应变式和电容式加速度传感器的测量结果进行了分析与比较 ,提出了在摆式列车倾摆信号测量系统中传感器的选型和质量评价标准 ,并给出了传感器的改进方向     

滚动轴承故障非接触多传感器声信号融合方法

摘　要：针对移动滚动轴承非接触声发射检测中,一个故障源信号可能被多个传感器采集,致使这些声信号包含故障信息不完整且存在重叠的问题,综合考虑声波传播理论、多传感器声信号时差关系、滚动轴承典型故障撞击频率等,建立滚动轴承故障非接触多传感器声信号融合方法。建立滚动轴承故障非接触多传感器声发射检测试验台,分别采集移动滚动轴承滚动体、外圈和内圈故障声信号。采用融合方法对同声源信号进行处理,利用信号相似理论证明了融合信号与故障源信号的相似程度高于各传感器声信号。采用声发射累计撞击计数法对融合处理后的滚动轴承不同故障声信号进行分析。结果表明,该融合算法能有效地处理多传感器接收的同声源信号,可利用融合后信号进行准确的故障识别。     

结构健康监测的光纤Bragg光栅传感器网络自修复实现

针对采用支持向量机理论识别飞机机翼盒段上外加载荷位置的光纤Bragg光栅传感器网络,研究了提高位置识别精度的方法;分析了网络中部分传感器失效对位置识别精度的影响,针对故障情况提出了基于模型重构的容错位置识别算法,并对采用容错位置识别算法前后载荷位置识别精度进行了详细的比较.研究结果表明:当网络中某个传感器失效时,通过模型重构容错位置识别算法可有效地实现传感器网络的自修复能力,提高传感器网络的可靠性.     

摆式列车倾摆伺服控制系统的研究

摆式列车是专门为提高列车曲线通过能力而设计的新型列车。摆式列车倾摆控制系统 (控制车体的倾摆 )是整个摆式列车成功与否的关键。在对摆式列车倾摆伺服系统特点进行分析的基础上 ,我们设计出一套基于MCS -5 1系列单片机的倾摆控制系统。试验表明 :该系统的控制性能能够满足摆式列车倾摆控制系统实时性和准确性的要求 ,具有较高的可靠性和实用价值。     

Prediction of displacement induced by tilting trains running on ballasted tracks through measurement of track impact factors

In the track design and behavior prediction, the variable contribution of wheel load was evaluated by considering the design load for the tracks. Further, the track impact factor was used to calculate the dynamic wheel load as a single value, which was chosen according to the rail type (i.e., continuous welded rail or joint rail) and the design speed but did not take into consideration the track conditions (i.e., the ballast condition good or bad), train type (i.e., tilting train and EMU), and track components (i.e., sleeper type and fastening type). In this study, the measured track impact factor was applied to the time history function of the FE analysis in order to predict the displacement of ballasted tracks under real conditions, which included curved and the deteriorated tracks, thus increasing the train speed by approximately 20–30% of the existing train speed. Therefore, the dynamic wheel load and the rail and sleeper displacement were measured for two different trains running on four conventional curved track sections with two different sleeper types. The track impact factor was estimated from the measured dynamic wheel load, and the empirical dynamic wheel load was calculated using the measured track impact factor at each site. The measured track impact factors were used for simulating the dynamic wheel loads applied on the derived time history function for fast trains. A finite element analysis model using the derived time history function based on the empirical dynamic wheel load was used to predict the train-induced track displacement. The numerical simulations and field test results were compared with German and Japanese regulations for train-induced track displacement, and the speedup effect of a tilting train was compared with that of a general train (EMU).The empirical track impact factors were 17–18% higher in the R400 sections than in the R600 sections. As the track curvature decreased, the impact on the track increased. Therefore, the empirical track impact factors were 21–23% higher in the WT sections than in the PCT sections. At 70 km/h, the impact on the track from a tilting train was 7–11% less than that from EMU. Although the tilting train sped up by 30% (90 km/h), its response level was similar to or less than that of the EMU. The analytical results reproduced the experimental results well within about 2–5% difference in the values. Therefore, the derived time history function based on the measured track impact factors is considered to provide sufficiently reliable FEA results in the investigation of the behavior of ballasted tracks. The difference between the maximum displacements for both train types on all the sections was about 15–20%.The analytical results show that the speed limits of the tilting train were higher than those of the EMU by approximately 8–23 km/h at each test site. Therefore, the speed limit of each test site was estimated by considering the limit of sleeper displacement. It was shown that the time history function derived using the measured track impact factor on a small track curvature with wooden sleepers was higher than that in other test sections. Therefore, it would be advantageous to increase the weight of sleepers on existing lines to increase the train speed through the speedup effect without increasing the track curvature. The increase in the speed of a tilting train with a small track curvature was much better than that by a track curvature increased by approximately 10%.     

Manufacturing and structural safety evaluation of a composite train carbody

This paper explains the manufacturing process of a composite train carbody with a sandwich composite structure for bodyshell and a stainless steel structure for the under frame. In addition, the structural behavior and safety of the composite carbody of the Korean tilting train was investigated by the static load tests. From the test results, the stiffness of the composite carbody met the specified design. In the aspect of strength, the maximum stress of the composite bodyshell was of 12.2% of strength of CF1263 carbon/epoxy.     

船载式水声定位系统信号处理改进算法研究

针对船载式水声定位系统的特点,在座底式等常规水声定位系统信号处理算法的基础上,对船载式系统可能出现的声脉冲叠加现象进行仿真分析,证明常规算法存在丢失数据的可能性,并且常规算法对声信号幅度变换较快的情况难以适应。提出一种并行实时数字信号处理算法,允许每块数据拥有不同的属性,并采用数据匹配方法进行后置冗余处理,获得有效数据。经过湖上跑船试验证明,该算法具有更高的检测率,并能提高跟踪轨迹的平滑性和真实性,具有较高的工程应用价值。     

压电倾斜镜迟滞非线性建模及逆补偿控制

自适应光学系统中的压电倾斜镜通常是用来实时校正大气湍流引起的波前畸变,但压电倾斜镜的响应都有较大的非线性迟滞效应,大大降低了倾斜镜的到位精度,并且影响系统稳定性,制约了倾斜校正系统的带宽,因此需要对迟滞现象进行建模,通过建立的模型进行补偿。本文通过引入迟滞算子,使用贝叶斯正则化训练算法训练BP神经网络来构建压电倾斜镜迟滞模型,以中国科学院光电技术研究所自主研制的压电倾斜镜为对象开展了实验研究。最后的实验结果表明,通过BP神经网络构建的压电倾斜镜迟滞模型具有较准确的辨识能力,其中,X方向的迟滞大小由6.5%降低到了1.3%,Y方向的迟滞大小由7.1%降低到了1.6%。     

An analysis of tilted magnetic transitions in magnetic recording media

A theoretical analysis of a transition is presented. The centerline of the transition through the media is tilted from the normal to the surface. For an isolated transition, it is shown that both the demagnetizing fields and the readback pulse shape are dependent upon the amount of tilting. For the case of sinusoidal recording, the tilting introduces an additional phase shift and amplitude reduction in the neadback signal. The signal amplitude reduction is shown to become oscillatory as the tilting increases.     

基于LabVIEW的车体振动加速度信号处理

车体耦合振动影响行车安全,因而研究车体振动加速度信号可以有效地测试火车的安全运行情况,为进一步改进车体结构,保障行车安全,采用加速度传感器对车体振动进行了在线检测。利用LabVIEW软件开发平台,采用滤波方法进行粗略地提取,实现车体振动加速度信号的显示和处理。实际表明,该系统结构简单,运行速度快,抗干扰性强,具有较高的可靠度。     

下承式钢板梁桥空间振动计算分析

本文提出了列车、下承式钢板梁桥空间振动的有限单元分析模型 ,采用计算机模拟方法 ,计算了提速列车以不同车速通过 3 2m下承钢板梁桥的空间振动响应 ,检算该桥是否具有足够的刚度及良好的运营平稳性 ,所得结果与实测资料相符 ,可供决策部门参考。     

Global Optimization of Costly Nonconvex Functions Using Radial Basis Functions

The paper considers global optimization of costly objective functions, i.e. the problem of finding the global minimum when there are several local minima and each function value takes considerable CPU time to compute. Such problems often arise in industrial and financial applications, where a function value could be a result of a time-consuming computer simulation or optimization. Derivatives are most often hard to obtain, and the algorithms presented make no use of such information.Several algorithms to handle the global optimization problem are described, but the emphasis is on a new method by Gutmann and Powell, A radial basis function method for global optimization. This method is a response surface method, similar to the Efficient Global Optimization (EGO) method of Jones. Our Matlab implementation of the Radial Basis Function (RBF) method is described in detail and we analyze its efficiency on the standard test problem set of Dixon-Szegö, as well as its applicability on a real life industrial problem from train design optimization. The results show that our implementation of the RBF algorithm is very efficient on the standard test problems compared to other known solvers, but even more interesting, it performs extremely well on the train design optimization problem.     

上承式钢板梁桥空间振动计算分析

本文提出了列车、上承式钢板梁桥空间振动的有限单元分析模型，采用计算机模拟方法，计算了列车提速后通过32m上承钢板梁板的空间振动响应，检算该桥是否具有足够的刚度及良好的运营平稳性，所得结果与实测资料相符，可供决策部门参考。     

Evaluation of structural safety of a tilting bolster

This study has performed the experimental study to assess the structural safety of a bolster frame that is applied to the bogie system of Korean tilting train. In order to achieve this goal, firstly, loading conditions imposed on the bolster frame were investigated. Based on the international standard and dynamic analysis, the loading conditions were derived. In this study, the dynamic load cases that consider the carbody tilting effect were established. The structural safety of the bolster frame was evaluated by static test under these static loads and the fatigue strength was assessed using Goodman diagram. From the assessment, the bolster frame has satisfied the structural safety. In addition, fatigue test was carried out up to 10 × 10⁶ cycles under tilting load condition established in this study. The inspection of fatigue crack using NDT method was conducted at 6 × 10⁶ and 10 × 10⁶ cycle.