Dynamic fault dictionaries and two-stage fault isolation

This paper presents dynamic two stage fault isolation for sequential random logic VLSI circuits, and introduces limited and dynamic fault dictionaries. In the first stage of the dynamic process, a limited fault dictionary identifies candidate faults, which are further distinguished in the second stage by a dictionary generated dynamically for the candidate faults and a subset of the test vectors. This provides high resolution but avoids the costs of full static dictionaries. Two-stage fault isolation is evaluated for benchmark circuits and on defects in industrial circuits     

适用于模数统一测试的故障隔离方法

介绍了一种实用的故障隔离方法及其实现。该方法既适用于模拟电路又适用于数字电路的故障隔离，已成功用于模数混合电路单元故障诊断系统。     

Cross-sectional nanoprobing fault isolation technique on submicron devices

With continuous scaling on CMOS device dimensions, it is becoming increasingly challenging for conventional failure analysis (FA) methods to identify the failure mechanism at the circuit level in an integrated chip. Scanning Electron Microscopy (SEM) based nanoprobing is becoming an increasingly critical tool for identifying non-visual failures via electrical characterization in current electrical FA metrology for fault isolation since 2006 Toh et al. (2007), Shen et al. (2007), Ng et al. (2012) . Currently, most of the nanoprobing fault isolation is nanoprobe in top-down planar direction, such as nanoprobe on via, contact and metal line. This paper focused on fault isolation of sub-micron devices by nanoprobing on a cross-sectional plane. This is a new application area; it is very useful for sample that cannot perform fault isolation with conventional top-down planar nanoprobing, especially on non-volatile memory that with single transistor memory array that arrange in a vertical direction, such as Magnetic Random Access Memory (MRAM), Phase-Change Random Access Memory (PC-RAM), flash memory and etc.     

大规模电路故障诊断神经网络方法

提出了一种采用BP神经网络诊断大规模电路故障的新方法。介绍了故障诊断的原则及BP网络的算法,并给出了仿真实例。实验证明所提出的方法是有效可行的。     

Intelligent fault isolation and diagnosis for communication satellite systems

NASA-Lewis Research Center recently completed the design of a Ka-band satellite transponder system, as part of the Advanced Communication Technology Satellite (ACTS) System. To enhance the reliability of this satellite, NASA funded The University of Akron to explore the application of an expert system, in order to provide this satellite with autonomous diagnosis capability. The result of this research was the development of a prototype diagnosis expert system, called Fault Isolation and Diagnosis EXpert (FIDEX). FIDEX is a frame-based system that uses hierarchical structures to represent such items as the satellite's subsystems, components, sensors, and fault states. This overall frame architecture integrates these hierarchical structures into a lattice that provides a flexible representation scheme and facilitates system maintenance. To overcome limitations on the availability of sensor information, FIDEX uses an inexact reasoning technique based on the incrementally acquired evidence approach that was developed by Shortliffe during his MYCIN project. The system is also designed with a primitive learning ability through which it maintains a record of past diagnosis studies. This permits it to search first for those faults that are most likely to occur. And finally, FIDEX can detect abnormalities in the sensors that provide information on the transponder's performance. This ability is used to first rule out simple sensor malfunctions. The overall design of the FIDEX system, with its generic structures and innovative features, makes it an applicable example for other types of diagnostic systems. This article discusses these aspects of FIDEX, and illustrates how they can be applied to fault diagnostics in other types of space systems.     

Generic fault isolation concept for telecommunication systems in access networks

This paper presents an approach for a generic fault isolation (FI) concept for telecommunication systems in the access network area. Based on a distributed processor architecture, a universal software structure for a FI unit is proposed. It is able to isolate faults, field replaceable units and is easily portable to different hardware platforms. The reusability of the FI unit is achieved by separating the software into generic control functionality and fully hardware-dependent software parts, i.e. user configurable tables and hardware-dependent control routines. The implementation of the concept is discussed in a ‘fiber to the building’-system which has already entered into mass-production. © 1997 John Wiley & Sons, Ltd.     

Automatic fault detection, isolation, and recovery in transparentall-optical networks

Network fault identification is an important network management function, which is closely related to fault management and has an impact on other network management functions such as configuration management, and performance management. This paper investigates fault surveillance and fault identification mechanisms for a transparent optical network in which data travels optically from the source node to the destination node without going through any optical-to-electrical (O/E) or electrical-to-optical (E/O) conversion. Mechanisms and algorithms are proposed to detect and isolate faults such as fiber cuts, laser, receiver, or router failures. These mechanisms allow nonintrusive device monitoring without requiring any prior knowledge of the actual protocols being used in the data transmission     

SOSP: an efficient multicast fault isolation scheme for multi-source sessions

This paper proposes a one-way source probing mechanism for fault isolation in multi-source multicast sessions. Routers involved in multicast record a routing path based on periodic probes from sources, and receivers isolate a fault region using the probes. We introduce a probe suppression mechanism to enhance the performance. The proposed scheme reduces message complexity and enhances fault isolation latency, which improves scalability. Furthermore, an analytical formula is proposed to estimate suppression time, which provides maximum performance for a given network status.     

Technologies for Heterogeneous Integration - Challenges and chances for fault isolation

The evolution of electronic devices for Integrated Circuits following Moore's law is one of the fastest industrial development speeds – and still far too slow for the rapid increase of performance requirements demanded by Internet of Things, growing cloud computing and other innovations in microelectronics. 2D scaling following Moore's law may come to an end from now on. But, the explosion of data collection, exchange and storage will require a dramatic increase of operating frequency, requiring very low power, low latency, sensors & actuators. All these aspects will have consequences for contactless fault isolation (CFI) that go far beyond the challenges of the past, being mostly imaging resolution and operating frequency with a given basic material of silicon. The presentation will check the readiness of CFI for the scaling still in expectation by assessing optical probing using visible light. Heterogeneous Integration aspects like radio frequency operation, the influence of new materials for actives, optical interconnects, ultra-shallow TSV will be checked for risks and new opportunities of CFI. Together with test, reliability and security requirements, a new world of electronic devices is envisioned and options are presented how challenges to CFI may be mastered by taking chances for new concepts of debug and failure analysis.     

MIL-1394B总线故障隔离方法研究和实现

MIL-1394B总线在国内外航空电子系统中应用越来越广泛,而MIL-1394B总线采用菊花链的物理层,单个节点的复位故障会导致整个网络的复位扩散,使整个网络不能正常通信。针对MIL-1394B总线在综合化航空电子设备的应用中故障难以隔离,提出一种通过先验信息隔离故障的方法。首先分析复位故障的原理,从而结合MIL-1394B总线在航空电子系统中预先分配节点号的先验信息,获取、分析AS643总线的SELF-ID包建立链接的信用值机制,设计一种检测信用值的方法,并改造节点的硬件设计,使节点链接的信用值低于阈值后可关闭错误链接,从而实现MIL-1394B的网络故障检测和隔离。该设计方法和机制通过实物系统进行验证,可用于高度综合化的航空电子系统中。     

A model of asynchronous machines for stator fault detection and isolation

This paper presents a new model of asynchronous machines. This model allows one to take into account unbalanced stator situations which can be produced by stator faults like short circuits in windings. A mathematical transformation is defined and applied to the classical abc model equations. All parameters which affect this new model can be known online. This makes the model very useful for control algorithms and fault detection and isolation algorithms. The model is checked by comparing simulation data with actual data obtained from laboratory experiments.     

NASA ground terminal communication equipment: Automated fault isolation expert systems

This paper describes the prototype expert systems that diagnose the Distribution and Switching System I and II (DSS1 and DSS2), Statistical Multiplexers (SM), and Multiplexer and Demultiplexer systems (MDM) at the NASA Ground Terminal (NGT) located at White Sands, New Mexico. A system-level fault isolation expert system monitors the activities of a selected data stream, verifies that the fault exists in the NGT and identifies the faulty equipment. Equipment-level fault isolation expert systems will be invoked to isolate the fault to a Line Replaceable Unit (LRU) level. Input and sometimes output data stream activities for the equipment are available. The system-level fault isolation expert system will compare the equipment input and output status for a data stream and perform loopback tests (if necessary) to isolate the faulty equipment. The equipment-level fault isolation system utilizes the process of elimination and/or the maintenance personnel's fault isolation experience stored in its knowledge base. The DSS1, DSS2, and SM fault isolation systems, using the knowledge of the current equipment configuration and the equipment circuitry, will issue a set of test connections according to the predefined rules. The faulty component or board can be identified by the expert system by analyzing the test results. The MDM fault isolation system correlates the failure symptoms with the faulty component based on maintenance personnel experience. The faulty component can be determined by knowing the failure symptoms.

The NGT fault isolation prototype is implemented in Prolog, C, and VP-Expert, on an IBM AT compatible workstation. The DSS1, DSS2, SM, and MDM equipment simulators are implemented in PASCAL. The equipment simulator receives connection commands and responds with status for the expert system according to the assigned faulty component in the equipment. The DSS1 fault isolation expert system was converted to C language from VP-Expert and integrated into the NGT automation software for offline switch diagnoses.

Potentially, the NGT fault isolation algorithms can be used for the DSS1, SM, and MDM located at Goddard Space Flight Center (GSFC). The prototype could be a training tool for the NGT and NASA Communications (Nascom) Network maintenance personnel.     

S1000D下故障隔离信息的研究与实现

介绍了IETM的基本概念和S1000D标准的特点,详细阐述了S1000D中故障信息数据模块的定义,并结合实例,给出了基于该标准的故障隔离模块的制作流程和实现方法,为开发IETM系统奠定了基础。     

Extension of the bond graph causality inversion method for fault detection and isolation

Controlled systems can be subjected to faults that may affect the performance of the system, and unable its objectives to be achieved. Fault detection and isolation algorithms are then used to study these faults. The bond graph tool can be used for modeling purposes and then its structural, and causal properties can be exploited for automatic generation of analytical redundancy relations (ARRs) through a procedure named causality inversion method, which are used for diagnosis applications. These ARRs are mathematical constraints that are used to verify the coherence between the process measurements and the system model. This paper proposes an extension of the causality inversion method by different versions of the same ARR. The goal is to increase the number of isolable faults. Moreover, structural conditions are given in order to avoid the generation of redundant ARRs. To validate the obtained structural procedure, a fault is imposed in a traction of an omnidirectional mobile robot.     

A geometric approach to fault detection and isolation of multi-dimensional (n-D) systems

Multidimensional Systems and Signal Processing - In this work, we develop a novel fault detection and isolation (FDI) scheme for discrete-time multi-dimensional (n-D) systems for the first time in...     

基于多协议层QoS参数关联的IPTV故障点定位方法

首先对IPTV马赛克、卡片等视频业务质量问题的原因进行深入分析,并与现有常用的IPTV监测方案对比,提出了一种创新的基于MPEG-TS层和RTP层QoS参数关联的IPTV业务质量分析与故障点定位方法.运维实践表明,该方法实施简便、经济有效,具有较强的推广价值.     

A built-in performance-monitoring/fault isolation and correction(PM/FIC) system for active phased-array antennas

A built-in performance-monitoring/fault isolation and correction (PM/FIC) system for an active phased-array antenna has been developed and tested. This PM/FIC system employs a transmission line signal injector embedded at the radiating aperture together with a phase-toggling technique for signal detection. Hardware components for a demonstration test-array have been developed, fabricated, and assembled. Eight active elements are fed by four dual-channel transmit/receive (T/R) modules in a column array. Far-field range tests and fault correction tests have also been performed to demonstrate the PM/FIC functions on this test array. Good results have been obtained from these tests. The measurement accuracy of the phase-toggling method is compared with an HP8510 measurement system     

Current imaging,EBIC/EBAC,and electrical probing combined for fast and reliable in situ electrical fault isolation

Using a compact nanoprobing setup comprising eight probe tips attached to piezo-driven micromanipulators, various techniques for fault isolation are performed on 28 nm samples inside an SEM. The employed techniques include nanoprobing as well as EBAC. The recently implemented Current Imaging technique is used to quickly image large arrays of contacts providing a means of locating faults. In this case, Current Imaging provides insight into the sample's behaviour yielding qualitatively comparable results to the more cumbersome cAFM technique. While the results of the TEM investigations including EDX mappings were inconclusive, the Current Imaging technique clearly shows that the root cause is located below the SiGe layer. By combining these techniques inside a FIB/SEM microscope, it is possible to locate and characterize a failure as well as prepare a TEM lamella for further investigation without the necessity to switch to a different tool.