基于LabVIEW的多通道sEMG信号检测系统设计

针对多通道信号检测系统在表面肌电信号sEMG(surface electromyography)信号检测分析中的应用,设计了一种基于LabVIEW的多通道sEMG信号检测系统。该系统由前置调理电路、数据接口卡以及LabVIEW软件编程部分组成。利用该系统采集并分析健康受试者完成指力跟踪动作时前臂指总伸肌上4通道sEMG信号时频域的特征值。实验结果表明,该系统能实现4通道sEMG信号的实时采集,并得到与手指力量相关的sEMG信号时域特征和频域特征,验证了所设计检测系统是可行的。     

基于sbRIO的多通道多类微弱小信号采集与处理

信号采集是实现船舶智能化的技术基础,针对船舶微弱信号传感器,提出一种基于single board RIO(简称sbRIO)的多通道多类微弱小信号兼容采集与处理方法.首先提出了多通道多类微弱小信号采集与处理总体方案,分析了传感器输出信号特点和采集性能指标要求,然后从软件和硬件两个方面详细阐述了采集处理机制原理和具体实现方案;最后搭建了原型板卡和上位机软件,进行了36通道测试、本底噪声测试、信号一致性测试、传感器兼容接入测试和多通道信号并行采集测试等功能性能指标的详细测试.实验结果表明,提出的采集方案可兼容接入多类传感器,同时本底噪声小、通道一致性良好,具有出色的采集调理性能,满足指标要求.     

基于经验小波变换的多通道微弱电流信号噪声控制

多通道微弱电流信号受很多噪声因素的干扰,导致微弱电流信号输出相对误差增加,为此提出基于经验小波变换的多通道微弱电流信号噪声控制方法。采集多通道微弱电流信号,利用经验小波变换技术分解采集到的微弱电流信号,判断电流信号中是否存在噪声并确定噪声类型。装设微弱电流信号噪声控制器,根据电流信号中的噪声量与噪声类型生成控制指令,对不同通道微弱电流信号噪声进行控制。实验结果表明,该方法的多通道微弱电流信号信噪比较高,输出信号与原信号之间的相对误差较小,可以实现多通道微弱电流信号噪声控制。     

TMS320F2812的多通道高速同步交流采样设计

在电力运行参数测控类应用系统中,采用AD73360型A／D转换器采集多路电压和电流信号,使用TMS320F2812实现了高速同步采样及电力参数在时域的计算;给出AD73360和TMS320F2812的硬件接口电路;采样系统采用C语言编程,给出了主程序、多通道缓冲串行接口初始化过程等的流程图;论述了采样接收中断、时域采样数据处理等技术。通过测试验证了设计方案的适用性和正确性。     

矿井提升机健康诊断系统设计

以LabVIEW软件为平台,设计了一种矿井提升机健康诊断系统。该系统利用传感器采集多个通道的连续数据,实现了对矿井提升机的实时在线监测;运用LabVIEW强大的信号采集和信号分析功能,并结合信息融合技术,实现了对矿井提升机信号的时域分析与频域分析,为矿井提升机的健康诊断提供了可靠依据。     

基于LabVIEW的舵机虚拟测试系统设计

围绕软件就是仪器的设计思想,设计开发了以计算机数据采集卡(PC-DAQ)为体系结构且基于LabVIEW软件平台的舵机虚拟测试系统.该测试系统可以实现舵机的线性、时域和频域特性测量,已应用于多种舵机的实际工程测试,显示出具有界面友好、使用方便、数据处理准确、测量重复精度高等特点.     

连铸结晶器振动数据在线采集与处理的LabVIEW实现

本文以铸坯连铸生产现况为背景,在连铸结晶器振动在线检测系统功能的基础上,结合虚拟仪器与LabVIEW的优势,详细阐述了系统对结晶器振动信号的实时采集方案与实现步骤。同时,文章还对振动信号的数据处理做了详细说明,给出了数字滤波器的实现程序,以及通过傅立叶变换实现的频谱分析图。文章最后给出的实际工程应用中系统采集到的振动信号时域波形和处理得到的频域频谱,充分证明了用LabVIEW实现的振动信号实时数据采集与处理取得了良好效果。     

超声多普勒流量信号的多声道互相关检测方法

针对低流速下的液体超声多普勒流量信号微弱杂乱、难以测量的问题,提出一种使用多个接收通道采集数据、进行多重互相关运算的处理方法,可以在不改变有用信号特征的前提下滤除噪声干扰,提取有用信号.首先利用FFT谱分析方法测得当前信号的频率范围,然后以合适的时间间隔在多个通道上同时进行数据采集,最后采用多重互相关的方法对数据处理提升信号的信噪比,达到弱信号提取的目的.经仿真和实验验证:在多通道上采集超声多普勒流量信号,使用多重互相关函数的数据处理方法能有效地提高弱强度信号在强背景噪声中的信噪比,对提升和改进超声波多普勒流量计的性能有良好效果,有效扩展测量下限.     

基于LabVIEW的高速多通道航天器通用测试系统设计

传统“微处理器+AD组件”的实现方式,在采集控制及数据处理等方面已很难满足多通道高速并行测试的需求。随着航天器系统及其设备复杂程度的逐渐提高,为满足航天器系统中多状态高速并行测试的要求,提出了一种基于LabVIEW的高速多通道航天器通用测试系统设计方案。该系统硬件架构采用PXI机箱、采集板卡、指令控制板卡及处理器板卡,同时基于LabVIEW平台进行系统软件开发,实现了多通道高速并行数据采集控制、数据实时显示、数据存储、数据回放及指令控制等功能。通过测试验证,该测试系统能够支持同时128通道在总采样率1KHz下的高速并行采集控制及后续数据处理,并能够支持64通道的指令配置及控制。通过长时间累积测试试验,结果表明本系统工作稳定可靠且通用性良好,具有很好的实用价值。     

轧制力在线智能监测虚拟仪器开发研究

本文介绍了一个利用虚拟仪器技术开发的轧制力在线智能监测系统。系统以PC工控机为主控平台,利用虚拟仪器开发软件LabVIEW7.1与使用PCI总线的高性能多通道数据采集卡相结合,实现对轧制力信号自动采集、判断、智能数据处理等功能。     

灰色预测模糊自适应PID控制的城轨列车智能驾驶系统研究

为提高城轨列车驾驶系统的智能化程度，将灰色预测控制与模糊自适应PID控制技术相结合，应用到城轨列车驾驶系统中。在对城轨列车驾驶系统进行需求分析的基础上，针对其对各种性能指标的要求，提出了基于灰色预测模糊自适应PID控制的城轨列车智能驾驶系统的设计方案。将灰色预测控制与模糊自适应控制应用到经典PID控制中，设计出了系统的智能控制器，有效满足了城轨列车在运行时对跟踪误差、准点率、停车误差、舒适度和节能性等多个性能指标的要求。仿真结果表明：采用灰色预测模糊自适应PID算法的控制系统具有良好的控制精度且系统的智能化程度得到了相应的提升。     

A new arc detection method based on fuzzy logic using S-transform for pantograph–catenary systems

pantograph–catenary system is one of the critical components used in electrical trains. It ensures the transmission of the electrical energy to the train taken from the substation that is required for electrical trains. The condition monitoring and early diagnosis for pantograph–catenary systems are very important in terms of rail transport disruption. In this study, a new method is proposed for arc detection in the pantograph–catenary system based signal processing and S-transform. Arc detection and condition monitoring were achieved by using current signals received from a real pantograph–catenary system. Firstly, model based current data for pantograph–catenary system is obtained from Mayr arc model. The method with S-transform is developed by using this current data. Noises on the current signal are eliminated by applying a low pass filter to the current signal. The peak values of the noiseless signals are determined by taking absolute values of these signals in a certain frequency range. After the data of the peak points has been normalized, a new signal will be obtained by combining these points via a linear interpolation method. The frequency-time analysis was realized by applying S-transform on the signal obtained from peak values. Feature extraction that obtained by S-matrix was used in the fuzzy system. The current signal is detected the contdition as healthy or faulty by using the outputs of the fuzzy system. Furthermore the real-time processing of the proposed method is examined by applying to the current signal received from a locomotive.     

城轨列车精确停车智能控制算法研究与仿真

随着我国城轨交通的大力发展,列车自动驾驶（ATO）系统在城轨列车中的应用越来越广泛,精确停车是衡量城轨列车自动驾驶性能重要指标之一。以精确停车、舒适性及能耗为指标,利用列车牵引计算知识建立列车运行多目标模型;利用遗传算法对该模型进行优化,结合MATLAB仿真软件得出列车运行理想目标曲线;运用SIMULINK模块分别搭建基于PID控制的仿真模型、基于模糊PID控制的仿真模型以及基于预测模糊PID控制的仿真模型,得出相应的列车运行跟踪曲线,并进行比较。结果表明：较前两者,预测模糊PID控制能最大程度地提高列车的停车精度。     

An integrated model for the transshipment yard scheduling problem

A hub-and-spoke railway system is an efficient way of handling freight transport by land. A modern rail–rail train yard consists of huge gantry cranes that move the containers between the trains. In this context, we consider a rail–rail transshipment yard scheduling problem (TYSP) where the containers arrive to the hub and need to be placed on a train that will deliver them to their destination. In the literature, the problem is decomposed hierarchically into five subproblems, which are solved separately. First, the trains have to be grouped into bundles in which they visit the yard. Next, the trains have to be assigned to tracks within these bundles, namely parking positions. Then the final positions for the containers on trains have to be determined. Next, the container moves that need to be performed are assigned to the cranes. Finally, these moves have to be sequenced for each crane for processing. In this paper, an integrated MILP model is proposed, which aims to solve the TYSP as a single optimization problem. The proposed formulation also enables us to define more robust and complex objective functions that include key characteristics from each of the above-mentioned subproblems. The strength of our proposed formulation is demonstrated via computational experiments using the data from the literature. Indeed, the results show that the TYSP can be solved without the use of decomposition techniques and more insight can be obtained from the same input data used to solve particular single decomposed subproblems.     

基于改进SSD算法的城市轨道交通多通道闸机控制研究

城市轨道交通多通道闸机独立工作,对多个闸机精准控制难度较大,所以研究基于改进SSD算法的城市轨道交通多通道闸机控制方法;将SSD网络与FPN网络相结合,结合先验框生成与损失函数优化实现SSD算法改进,利用改进SSD算法和数据融合结果识别通行目标;根据通行目标识别结果和传感器设备确定闸机通道内的通行情况,从而设计多通道闸机控制处理子程序,完成城市轨道交通多通道闸机控制;实验结果表明,在改进SSD算法作用下,闸机闭合状态始终与行人的当前行进方向保持一致,提高了控制精准度和实时通过率。     

NDE system for railway wheel inspection in a standard FPGA

A special NDE system built into a low-cost FPGA has been developed for detecting railway wheelflats. The system operates with the train moving at low-speed over a measuring rail. Ultrasonic surface wave pulses are sent at regular intervals and echoes are acquired and processed by the system. The variations in the round trip time-of-flight (RTOF) of the ultrasonic pulse allow to detect and quantify the flats size.The logic design optimizes the storage capabilities by keeping only the rail–wheel contact echo and its environment. For this purpose, a wheel tracking algorithm has been implemented. It allows reducing the data volume by controlling the delay time from pulse emission to the acquisition window following the running wheel. Furthermore, since signals are masked by the rail structural noise, they are processed before executing the tracking algorithm. This work presents the architecture and performance of the developed system with experimental data.     

Exact train pathing

Suppose we are given a schedule of train movements over a rail network into which a new train is to be included. The origin and the destination are specified for the new train; it is required that a schedule (including the path) be determined for it so as to minimize the time taken without affecting the schedules for the old trains. In the standard formulations of this single train pathing problem, the time taken by the train to traverse any block (track segment guarded by a signal) in the network is deemed to be a fixed number, independent of how the train arrived onto that block. In other words, the standard formulations of train pathing do not accurately model the acceleration/deceleration restrictions on trains. In this paper we give an algorithm to solve the single train pathing problem, while taking into account the maximum allowed acceleration and deceleration as well as explicitly modeling signals. For trains having ‘large’ maximum acceleration and deceleration, our algorithm runs in polynomial time. On the other hand, if the train to be pathed is capable of only very small acceleration so that it must take a long time to reach full speed, our algorithm takes exponential time. However, we prove that the pathing problem is NP-complete for small acceleration values, thus justifying the time required by our algorithm. Our algorithm can be used as a subroutine in a heuristic for multiple train pathing. If all trains have large (but possibly different) accelerations this algorithm will run in polynomial time. V. Nagarajan is supported in part by NSF grant CCF-0728841.     

城轨美式应答查询器状态分析与故障检测

城市轨道交通中应答器传输系统是对行进列车进行精确定位的关键系统,列车定位是保证基于通信的列车控制系统（CBTC）安全高效工作的前提。在运营过程中,应答器传输系统在因线路老化、列车振动、设备故障等原因出现信标丢失的故障,导致无法对列车进行定位而引起列车制动,这对列车运行造成极大的影响,更是线路运营的重大安全隐患。目前城市轨道交通中针对车载设备的故障,采取的检修方法是整体更换故障设备,维修成本高且效率低下。为减少车载设备故障情况,本文通过对应答器传输系统中的美式应答查询器的工作状态进行研究,旨在根据其工作状态判断应答查询器故障的具体位置,提出了一种针对应答查询器的故障的检测流程,为城轨车载设备的故障检测提供了指导,有良好的应用价值与实际意义。     

铁轨压力状态监测无线传感系统的设计

为满足城轨及列车安全运行的需求,根据铁轨延伸地形特点,设计了一种可靠的无线传感网络列车钢轨压力状态监测系统。详细阐述了以CC2430为核心的传感器节点、以CC2430和MCP2515为核心的网关节点的软硬件设计方法和工作流程。通过某车站的实地试验,测得2.4 GHz频率在铁路现场的传输特性。当两相邻节点间距最远为60 m时,系统仍可实时、稳定地工作。     

改进WFQ算法在列车网络调度中的应用研究

随着我国轨道交通迅猛地发展,基于TCN的列车网络已经不能满足列车数据传输业务的需求,列车控制与服务网络TCSN应运而生。针对列车数据传输业务研究了基于综合服务模型的列车通信网络,建立了四类列车业务流量模型,分析了网络分组的加权公平队列调度算法（WFQ）,设计了基于服务分类和带宽分配的加权公平队列调度算法（SCBAWFQ）,并且利用仿真软件对恒定数据流和突发数据流分别在WFQ与SCBAWFQ算法下的时延进行了仿真与分析,仿真结果证明改进算法在降低实时业务流延时方面有很好的效果,SCBAWFQ算法既保持了WFQ算法的公平性又满足实时业务服务质量的需求。