Novel Double Modular Redundancy Based Fault-Tolerant FIR Filter for Image Denoising

In signal processing and communication systems,digital filters are widely employed.In some circumstances,the reliability of those systems is crucial,necessitating the use of fault tolerant filter implementations.Many strategies have been presented throughout the years to achieve fault tolerance by utilising the structure and properties of the filters.As technology advances,more complicated systems with several filters become possible.Some of the filters in those complicated systems frequently function in parallel,for example,by applying the same filter to various input signals.Recently,a simple strategy for achieving fault tolerance that takes advantage of the availability of parallel filters was given.Many fault-tolerant ways that take advantage of the filter’s structure and properties have been proposed throughout the years.The primary idea is to use structured authentication scan chains to study the internal states of finite impulse response(FIR)components in order to detect and recover the exact state of faulty modules through the state of non-faulty modules.Finally,a simple solution of Double modular redundancy(DMR)based fault tolerance was developed that takes advantage of the availability of parallel filters for image denoising.This approach is expanded in this short to display how parallel filters can be protected using error correction codes(ECCs)in which each filter is comparable to a bit in a standard ECC.“Advanced error recovery for parallel systems,”the suggested technique,can find and eliminate hidden defects in FIR modules,and also restore the system from multiple failures impacting two FIR modules.From the implementation,Xilinx ISE 14.7 was found to have given significant error reduction capability in the fault calculations and reduction in the area which reduces the cost of implementation.Faults were introduced in all the outputs of the functional filters and found that the fault in every output is corrected.

Research on static characteristic of double redundance double nozzle flapper valve based on AMESim

The feedback spring rod of the armature assembly is cancelled in the double redundance double nozzle flapper valve(DRDNFV),and the difficulty of valve core displacement control is increased.Therefore,this paper intends to study the static characteristic of DRDNFV through the AMESet and AMESim simulation.It is explored under the circumstance of the fixed orifices being clogged and experimentally verified on the test bench.The results show that the pressure gain increases and the flow gain decreases with the increasing clogged degree of the fixed orifices on both sides.The zero bias increases synchronously with the increasing clogged degree of the unilateral fixed orifice.The experimental results are basically consistent with the theoretical curves and the theoretical correctness of the simulation model is effectively verified.The results can provide the theoretical reference for design,debugging,maintenance and fault diagnosis of DRDNFV.

Decadal Forecasts of Large Earthquakes along the Northern San Andreas Fault System, California: Increased Activity on Regional Creeping Faults Prior to Major and Great Events

The three largest earthquakes in northern California since 1849 were preceded by increased decadal activity for moderate-size shocks along surrounding nearby faults. Increased seismicity, double-difference precise locations of earthquakes since 1968, geodetic data and fault offsets for the 1906 great shock are used to re-examine the timing and locations of possible future large earthquakes. The physical mechanisms of regional faults like the Calaveras, Hayward and Sargent, which exhibit creep, differ from those of the northern San Andreas, which is currently locked and is not creeping. Much decadal forerunning activity occurred on creeping faults. Moderate-size earthquakes along those faults became more frequent as stresses in the region increased in the latter part of the cycle of stress restoration for major and great earthquakes along the San Andreas. They may be useful for decadal forecasts. Yearly to decadal forecasts, however, are based on only a few major to great events. Activity along closer faults like that in the two years prior to the 1989 Loma Prieta shock needs to be examined for possible yearly forerunning changes to large plate boundary earthquakes. Geodetic observations are needed to focus on identifying creeping faults close to the San Andreas. The distribution of moderate-size earthquakes increased significantly since 1990 along the Hayward fault but not adjacent to the San Andreas fault to the south of San Francisco compared to what took place in the decades prior to the three major historic earthquakes in the region. It is now clear from a re-examination of the 1989 mainshock that the increased level of moderate-size shocks in the one to two preceding decades occurred on nearby East Bay faults. Double-difference locations of small earthquakes provide structural information about faults in the region, especially their depths. The northern San Andreas fault is divided into several strongly coupled segments based on differences in seismicity.

Novel active fault-tolerant control scheme and its application to a double inverted pendulum system

On the basis of the gain-scheduled H∞ design strategy, a novel active fault-tolerant control scheme is proposed. Under the assumption that the effects of faults on the state-space matrices of systems can be of affine parameter dependence, a reconfigurable robust H∞ linear parameter varying controller is developed. The designed controller is a function of the fault effect factors that can be derived online by using a well-trained neural network. To demonstrate the effectiveness of the proposed method, a double inverted pendulum system, with a fault in the motor tachometer loop, is considered.

A FAULT DETECTION SENSOR FOR CIRCUIT AGING USING DOUBLE-EDGE-TRIGGERED FLIP-FLOP

In nanoscale technology, transistor aging is one of the most critical problems that impact on the reliability of circuits. Aging sensor is a good online way to detect the circuit aging, which performs during the operating time with no influence of the normal operation of circuits. In this paper, a Double-edge-triggered Detection Sensor for circuit Aging (DSDA) is proposed, which employs data signal of logic circuits as its clock to control the sampling process. The simulation is done by Hspice using 45 nm technology. The results show that this technique is not sensitive to the process variations. The worst case of the detection precision is more than 80% under the different process variations. It can detect aging fault effectively with the 8% power cost and 30% performance cost.

Fault location of two-parallel transmission line for double phase-to-earth fault using one-terminal data

An accurate algorithm for fault location of double phase-to-earth fault on transmission line of direct ground neutral system is presented. The algorithm, which employs the faulted phase network and zero-sequence network as fault-location model in which the source impedance at the remote end is not involved, ef-fectively eliminates the effect of load flow and fault resistance on the accuracy of fault location. The algorithm achieves accurate location by measuring only one local end data and is used in a procedure that provides automatic determination of faulted types and phases, and does not require the engineer to specify them. Simulation results showed the effectiveness of the algorithm under the condition of double phase-to-earth fault.

Fault Locator Using Two-end Unsynchronized Measurements for UHV Series Compensated Double-circuit Lines

An accurate fault location algorithm for double-circuit series compensated lines is presented.Use of two-end unsynchronized measurements of current and voltage signals is considered.The algorithm applies two subroutines,designated for locating faults on particular line sections,and additionally the procedure for selecting the valid subroutine.The subroutines are formulated with use of the generalized fault loop model and the distributed parameter line model is applied.Performed ATP-EMTP based evaluation has shown the validity of the derived fault location algorithm and its high accuracy.

A Novel Fault Location Algorithmfor Double-Circuit Transmission Lines based on Distributed Parameter

Anewfault location algorithmfor double-circuit transmissionlines is described inthis paper.Theproposed method uses data extractedfromtwo ends of the transmissionlines andthus eliminates the effects ofthe source impedance andthe fault resistance.The distributed parameter model and the modal transformationare also employed.Depending on modal transformation,the coupled equations of the lines are converted intodecoupled ones.Inthis way,the mutual coupling effects between adjacent circuits of the lines are eliminatedandtherefore an accurate fault location can be achieved.The proposed methodis tested via digital simulationusing EMTP in conjunction with MATLAB.The test results corroborate the high accuracy of the proposedmethod.

利用双差走时成像研究青藏高原东缘地壳速度结构

青藏高原东缘断裂密布,强震频发,是研究高原侧向挤出及深部孕震环境的理想实验室.为了解龙门山次级块体及其西界龙日坝断裂带在青藏高原东缘隆升过程中的作用,我们基于四川地震台网64个宽频带地震台在2008年1月至2015年12月期间记录的震级≥3.0地震事件波形,利用双差层析成像方法揭示了四川盆地及青藏高原东缘的地壳速度结构.结果表明:夹持于龙门山断裂带(LMSF)与龙日坝断裂带(LRBF)之间的龙门山次级块体,相对东侧龙门山断裂带和四川盆地呈现明显的低速特征.结合该区域的低阻、低密度结构特征,以及块体内部、特别是龙日坝断裂带现今地震活动缺乏,我们推测这是因为该块体“相对较软”,不易脆性破裂产生地震,在青藏高原东缘与扬子块体西缘强烈相互作用过程中,该块体主要通过地壳缩短增厚和地表隆升吸收板块挤压造成的累积应变能.依据本文获得的速度等值线变化特征及已有地球物理剖面探测结果,推测龙日坝断裂带为深部向南东倾斜且向下切入基底,该断裂倾角较陡,主要以走滑运动调节应变能,而东侧龙门山断裂带倾角较缓,表现为逆冲运动导致的地壳缩短是其调节应变能的主要形式.此外,据本文多条速度剖面及已有电性剖面、重力异常的联合约束,我们推测鲜水河、安宁河断裂带均以较大倾角向南东倾斜,至少延伸至中下地壳.

多源冗余容错导航计算系统的设计与实现

常规无人机在余度配置传感器的信号处理、余度管理、故障检测与隔离等环节占用飞控计算机过多运算资源,增加了飞控计算机的整体负荷,致使全系统可靠性降低;与此同时,传统的传感器余度配置方案和导航计算机余度设计在工程中存在方案不完备和实时性较差等局限性。鉴于此,提出一种多源冗余容错导航计算系统的解决方案,给出系统的软硬件设计方法,并基于非相似余度技术设计多源冗余传感器硬件和软件滤波算法,采用双CPU+FPGA的架构设计多源冗余容错导航计算机硬件平台以及模块化软件架构,实现了系统的软硬件的开发。经过实际测试和试验,验证了系统具有通信速率快、可靠性高和稳定性好等特点,满足了高可靠性飞控系统对新型组合惯导的需求。

一种用于信息处理微系统DDR互连故障的自测试算法

为解决信息处理微系统中双倍速率同步动态随机存储器(Double Data Rate,DDR)复杂互连故障的检出效率和测试成本问题,通过分析DDR典型互连故障模式,将单个存储器件的自动测试设备(Auto Test Equipment,ATE)测试算法与板级系统的系统级测试(System Level Test,SLT)模式相结合,提出面向DDR类存储器的测试算法和实现技术途径。并基于现场可编程门阵列(Field Programmable Gate Array,FPGA)器件实现微系统内DDR互连故障的自测试,完成了典型算法的仿真模拟和实物测试验证。相较于使用ATE测试机台的存储器测试或通过用户层测试软件的测试方案,本文所采用的FPGA嵌入特定自测试算法方案可以实现典型DDR互连故障的高效覆盖,测试效率和测试成本均得到明显改善。

不对称故障下低电压穿越的多目标解耦控制策略

在传统不对称故障低电压穿越控制中,由于控制自由度有限,并网逆变器控制存在无法同时实现输出电流负序分量和直流侧电压二倍频波动抑制的问题。对此,文中提出一种不对称故障下两级式光伏并网系统低电压穿越的多目标解耦控制策略。该策略将逆变器的控制目标设置为输出电流负序分量抑制,给出了综合考虑逆变器输出电流限幅和无功输出需求的逆变器电流内环控制参考值计算方法;通过双向Buck-Boost变换器将超级电容接入直流母线电容两端维持其电压稳定,并将直流侧电压二倍频波动转移至超级电容输入侧进行抑制。仿真结果表明,相比传统控制方法,所提控制策略有效降低了逆变器三相间的不平衡度,改善了输出电流畸变,减小了直流侧电压二倍频波动。

用于直流微电网线路的新型不平衡保护研究

直流微电网中所配置的线路保护需要兼顾速动性与选择性,为解决这一难题,提出了一种基于双回供电线路的直流微电网线路保护方案。通过分析直流微电网双回路供电下的线路故障特征,发现双回路的供电形式能提供故障状态下的不平衡信息,使得保护装置通过基于单端测量获取的电流信号量实现故障检测,同时双回路的供电方式采用本方案能清除线路的故障部分而不会影响供电。针对典型的极地故障,通过仿真的形式验证了所提保护方案的可行性。

论监管科技的双层容错机制

数字经济发展进入“深化应用、规范发展和普惠共享”时期,金融科技与监管科技却仍处于错步演进过程中。监管科技创新易于失败有其特殊性和深刻根源,有必要强化监管科技和金融科技双层容错机制。在监管机关、第三方技术提供方和被监管机构的三元目标冲突下,监管科技与合规科技面临衔接失灵的困境,应转变理念走向容错性监管。容错性监管并非不监管抑或运动式监管,而是按照法定程序给予相对容错空间,激励创新并推动实现可持续发展的监管,其以社会整体利益为导向,强调在常态化监管中稳定预期。在双层容错机制中,中央金融委员会和中央金融工作委员会是上层容错主体,容错免责的客体是担当作为、勇于创新的金融监管者,容错内容应从单纯的开发区域试验田,向全面推动监管科技创新发展与风险防范双头并进转化,同时突出程序优先性与问责精准化。

基于光学影像相关性匹配技术的2023年土耳其M_(W)7.8与M_(W)7.5双强震地表同震变形研究

2023年2月6日在土耳其中南部卡赫拉曼马拉什省10个小时内连续发生M_(W)7.8与M_(W)7.5双强震,震源机制解表明两个地震均为走滑型地震。土耳其双强地震发生后,国内外学者利用野外测量、GNSS以及差分InSAR等方法开展了一系列地表同震变形研究,但由于所采用的技术手段限制,当前已有地表同震变形结果尚存在空间分辨率低、近断层处数据缺失等不足。为了弥补这些不足,研究利用哨兵2号光学影像数据,通过影像相关性匹配技术得到了土耳其双强震的东西向和南北向的地表同震变形场,并将这些地表变形转换成为沿着断层方向的左旋走滑位移。变形场结果显示两次地震地表破裂长度分别约280 km和约130 km,首先发生的M_(W) 7.8地震的平均走滑位移量为4.2±1.66 m,最大走滑位移量6.9±0.81 m;随后发生的M_(W)7.5地震的平均走滑位移量为4.9±2.45 m,最大走滑位移量为9.6±1.16 m。通过对比COSI-Corr方法和野外测量得到的水平位移,结果显示2种方法得到的最大水平位移相吻合,而COSI-Corr方法得到的平均位移略大于野外测量得到的水平位移,这是由COSI-Corr方法测量结果中包含了部分离断层弥散变形导致的。研究结论不仅可为断层面滑动反演模型提供变形数据和约束条件,同时可以加深对走滑断裂的破裂行为控制因素的理解。

双闭环比值控制系统传感器故障诊断方法

双闭环比值控制系统由于主从回路滞后效应和闭环回路调节作用,使其故障诊断较为复杂。针对该系统传感器故障难以识别的问题,通过分析反映系统动态特性的实时数据,提出一种基于数据驱动的故障诊断方法。利用拉伊达准则标定检测阈值建立故障检测模型;利用传感器故障传播的滞后特性建立故障定位模型;利用突变故障的幅值特性建立了故障估计模型;利用故障调节动态过程的变化趋势建立了故障分离模型;通过在线数据标定获得了故障诊断动态模型。通过实验验证该方法的有效性和高精度。研究结果表明,所提方法适用于一般双闭环比值控制系统传感器的实时故障诊断,其中故障检测准确率可达98.5%,故障定位准确率可达98.5%,故障估计准确率可达99.28%,故障分离准确率可达98%。

基于改进过压限制器和ACDTS的混联半波长系统故障保护策略

交直流混联半波长输电系统的暂态特性与常规的混联系统存在着很大差异。当混联系统半波长沿线发生不对称故障时,直流系统会受到沿线工频过电压和过电流的冲击。文章详细分析了混联系统半波长沿线故障的传播过程,研究了故障传播耦合机理。针对直流侧过电压问题,提出了在直流母线侧加装改进过压限制器,增设辅助限压通道,分级抑制直流侧过电压,并降低单个通道的电流值,提高了系统保护的限压水平;另一方面,对于直流侧过电流问题,提出了在换流站接口端并联接入双向晶闸管,实现交流系统等效三相短接,隔离交流侧母线馈入的故障过电流,确保换流站设备及线路的安全性。最后利用仿真验证了两种保护策略的可行性。

双闭环管理模式在血液透析机保养及故障管控中的价值研究

目的:构建医疗设备双闭环管理模式,探讨其在血液透析机保养及故障管控中的应用价值。方法:基于医疗设备临床运行闭环管理和技术保障闭环管理,构建医疗设备双闭环管理模式。选取2021年1月至2023年1月复旦大学附属华山医院临床在用的65台血液透析机,分别采用常规设备管理方法(简称常规模式)管理和双闭环管理模式(简称双闭环模式)管理。对比两种管理模式血液透析机的成本效益、社会效益、故障发生情况、管理质量有效事项、消毒情况、患者平均等候时间和患者满意度。结果:双闭环模式的血液透析机运行利润增长率、诊疗费用增长率、使用年限指数(I_(年限))百分比、科研服务增长率、诊疗服务增长率、开机率和运转率分别为(3.95±1.04)%、(3.80±0.58)%、(1.58±0.31)%、(4.30±0.95)%、(7.91±1.58)%、(96.58±2.76)%和(89.90±5.58)%,均高于常规模式,其差异有统计学意义(t=5.418、10.070、7.490、17.570、11.820、8.849、6.840,P<0.05);技术保障费用支出增长率、细菌菌落数、细菌内毒素含量和患者平均等待时间分别为(2.60±0.33)%、(0.370±0.008)cfu/ml、(0.0063±0.0011)EU/ml和(0.76±0.13)h,均少于常规模式,其差异有统计学意义(t=23.040、82.985、14.482、19.530,P<0.05)。双闭环模式的血液透析机故障发生为6台(占9.23%),低于常规模式,其差异有统计学意义(x^(2)=6.392,P<0.05);采集的120项管理数据中质量控制检测、维护维修、临床操作、信息数据和报废处理的有效数据分别为115项(占95.83%)、107项(占89.17%)、116项(占96.67%)、114项(占95.00%)和117项(占97.50%),管理数据有效率均高于常规模式,其差异有统计学意义(x^(2)=15.238、16.596、9.808、15.585、16.119,P<0.05)。结论:双闭环管理模式应用于血液透析机保养及故障管控,能够有效提升设备成本效益、社会效益、管理质量及患者满意度,降低故障发生率。

电液阀故障气动半实物仿真平台设计

针对阀口独立电液阀故障诊断与状态感知功能开发需求,设计搭建了一种基于高速开关阀与低惯量气缸驱动的高频阀芯-电磁铁加载与故障半实物仿真试验平台,并对试验台性能进行了初步测试。该仿真平台通过PWM信号驱动高速开关阀控制双作用气缸活塞杆位移与输出力,调控加载于阀芯比例电磁铁的模拟工况,实现电液阀阀内故障的半实物模拟。试验平台基于ARM平台建立,集成了场效应驱动电路与位移传感器、拉压力传感器与电流传感器等感知元件,可完成对模拟工况下阀芯的动态特征的捕捉。初步试验结果表明,通过设置不同PWM驱动信号可实现阀芯加载力调节、实现阀芯卡滞模拟,验证了平台功能。

双高棒产线关键设备智能运维设计及应用

以双高棒产线设备智能运维的架构设计和应用实践为研究方向,梳理了国内双高棒产线的建设及智能运维的应用情况。基于设备故障信号特征、健康趋势分析等研究内容,以设备全国产化双高棒产线为应用对象,创新性地基于工业互联网构建智能运维体系。多方协同建立故障结构树、故障特征数据库、设备数字档案,以实现移动终端上查看、统计、管理设备故障隐患的功能。案例应用结果表明,自产线投运及实施智能运维管理以来,双高棒产线关键设备在线监测覆盖率达到100%、点巡检负荷量下降60%、非计划停机时间下降35%、运维成本降低25%。该研究成果将推动在线监测、故障诊断、工业互联网技术的融合应用,对轧钢产线的智能运维建设具有示范作用。