Causal Analysis for Troubleshooting and Decision Support System
Byoung Uk Kim, Sonia Vohnout, Esko Mikkola, Mingyang Li, Jian Liu
2011 IEEE Conference on Prognostics and Health Management
For today’s complex systems (e.g., military aircraft), rigorous routine inspection and maintenance is performed to ensure the health of the plane’s numerous mechanical and electronic systems. While vital, this constant process has seen significant cost increases over the past 10 years as various cost components, including labor, parts and aircraft downtime, rise in conjunction with the increasing complexity of these systems. This foundation provides the background necessary to develop an effective troubleshooting and decision support system for complex system faults/failures and ultimately provides substantial benefits to the maintainer of complex systems and maintenance facilities.
Often difficult and complex, failure diagnosis and troubleshooting for decision support classically focuses mainly on the component level without considering potential interactions between components in larger complex systems.
We have developed an innovative, constraint-based causal analysis to better detect, isolate, and troubleshoot complex systems. The feasibility of the causal Bayesian network (CBN) approach has been proven with implementation using test data acquired from electromechanical actuator (EMA) systems. The validation step is facilitated by comparing the trained CBN with original structure and shows the flexibility and extensibility of our solutions. This causal analysis processing in integrated system health management (ISHM) will enable enhancements in flight safety and condition-based maintenance (CBM) by increasing availability and mission-effectiveness while reducing costs.
For the complete paper, go to IEEExplore at: http://ieeexplore.ieee.org/document/6024344/
RGI internal document title for reference only: IEEE-PHM2011-Conference-Final-Manuscript-Ridgetop.pdf
Advanced Diagnostics and Anomaly Detection for Railroad Safety Applications: Using a wireless, IoT-enabled measurement system
Douglas L. Goodman, James Hofmeister, and Robert Wagoner
2015 IEEE AutoTestCon
Sensors are at the heart of effective diagnostic measurement systems, and flexibility for integration into diverse platforms is required. Wireless internet technology, including Internet of Things (IoT), opens new avenues of supporting rigorous remote testing, diagnostic and prognostic systems. In a comprehensive prognostics and health management (PHM) system, sensor measurements are critical to providing the observability necessary to support the monitoring of spatially separated systems. Wireless technology supports selection of individual or multiple sensor input streams through a gateway collection hub where signal processing can be applied to the data stream to extract anomalies or degraded performance attributes; wireless technology enables use of unique IP addresses that can be interrogated for sensor measurements on an ongoing, near real-time basis; and standard wireless protocols can be used to feed sensor information from deep inside an enclosure such as a gearbox.
Collecting and processing measurement data is not straightforward because of many factors, including but not limited to noisiness of data from a sensor mounted on a boxcar axle, and volume of digital data from high-bit resolution analog-to-digital data converters (ADCs). Wireless technology facilitates the transmission of digital data to a data-collection hub where a microprocessor transforms three-dimensional bit data into scalar data.
This paper details the results of an experiment using a sensor system mounted on one of the 110 boxcars on a train on a high-tonnage loop test track. The sensor was a microelectromechanical systems (MEMS) triaxial accelerometer module mounted on the hubs of the wheels of the boxcar. Sensor data were wirelessly transmitted to a collection gateway hub mounted inside the boxcar. The purpose of the experiment was to evaluate the feasibility of using a rotating triaxial accelerometer-based system designed to be mounted inside of a helicopter gearbox, and to use the system to detect anomalies in railroad tracks and rolling stock as well as anomalies of bearings, rotating shafts and gears. The results confirm it is feasible to identify, locate, and characterize anomalies.
For the complete paper, goto IEEExplore at: http://ieeexplore.ieee.org/document/7356502/
RGI internal document title for reference only: Ridgetop-Group-Autotestcon2015-Advanced-Diagnostics-and-Anomaly-Detection-for-Railroad-Safety-Applications.pdf
An Innovative 2.5D IC Interconnection Reliability System
Andrew Levy, Hans Manhaeve, Ed McBain
2013 IMAPS Conference
In this paper we present a new methodology that addresses the quality and reliability problems of applications that deploy ”2.5D” packaging technology for integrated circuits (ICs). This technology employs through-silicon vias (TSVs), enabling greatly increased circuit density, performance, and functionality for a given volume. The 2.5D ICs require the use of an interposer to route signals between the chips and the package substrate. While this packaging solution has some distinct advantages over other packaging/mounting technologies, there are disadvantages as well. Qualifying and testing such connections is very difficult and expensive, and techniques for anticipating failure do not currently exist. Therefore, confidence in the reliability of 2.5D IC interconnects is lacking. Systems that use them may require a high level of preventive maintenance whenever possible, or such packaging may simply be avoided when such maintenance is not possible or practical.
The paper outlines an approach that combines embedded digital and analog measurement instruments that are capable of detecting and identifying opens and shorts in 2.5D IC TSV stacks. The monitors reside on the silicon interposer. This system is the first to address the difficult issue of 2.5D IC package interconnect integrity after assembly is done and when the related devices are deployed in larger systems. The innovation will improve reliability of TSV-based packaging by detecting and identifying faulty connections at package test during the manufacturing process. It also provides prognostic monitoring so that interconnect-related operational faults can be detected before actual system failure occurs after the packaged component is deployed in the field.
For the complete paper, go to iMAPSource at:
RGI internal document title for reference only: WP_IMAPS-2013-Extended-abstract-same-as-PDF-2.5D-IC-Interconnection-Reliability.pdf
TSV BIST: An Innovative Method for 2.5D/3D IC Interconnection Integrity Monitoring
Hans Manhaeve, Ph.D, Andrew Levy, Chih-Yang Li
In this paper, we present a new present a new test methodology that addresses the quality and reliability problems of integrated circuits that deploy “2.5D” and “3D” packaging. These technologies employ complex interconnects using through-silicon vias (TSVs), enabling greatly increased circuit density, performance, and functionality for a given volume. The 3D ICs stack directly on top of each other, with interconnections being made by matching TSVs. The 2.5D ICs are similar, however they require the use of an interposer to route signals since the TSVs do not directly correspond to the IC above or below. While these packing solutions have distinct advantages over other packaging/mounting technologies, there are disadvantages as well. The increased density leads directly to increased heat, thus degradation and defects due to thermal effects are of great concern. Qualifying and testing such connections is very difficult and expensive, and techniques for anticipating failure do not currently exist. Therefore, confidence in the reliability of 3D IC/2.5D IC interconnects, especially after deployment in the field, is lacking. Systems that use them may require a high level of preventive maintenance where that is possible, or such packaging may simply be avoided when such maintenance is not possible or practical.
This paper outlines TSV BIST, an approach that combines embedded digital and analog measurement instruments that are capable of detecting and identifying opens and shorts in 2.5D IC and 3D IC TSV stacks. The TSV BIST monitors can reside on a silicon interposer (for 2.5D ICs), be embedded as die (for 2.5D ICs or 3D ICs) or as small IP cores embedded in one or more ICs in a 2.5D or 3D stack. This method is the first to address the difficult issue of 3D IC/2.5D IC package interconnect integrity after assembly is done and when the related devices are deployed in larger systems. The innovation will improve reliability of TSV-based packaging by detecting and identifying faulty connections at package test during the manufacturing process. TSV BIST also provides prognostic monitoring so the interconnect-related operational faults can be detected before actual system failure occurs after the packaged component is deployed in the field.
For the complete paper, go to at:
(Link pending review)
RGI internal document title for reference only: WP_ITC-3D-TEST-Workshop-TSV-BIST-2-5D-3D-IC-Interconn-Integrity-Mon_copyrighted.pdf
Rapid Characterization Method for New Semiconductor Processes
Hans Manhaeve, Ph.D, Andrew Levy, Esko Mikkola, Ph.D
2013 ETS Conference
Having adequate characterization of new semiconductor processes is important in the development of integrated circuits (ICs) destined for mil/aero systems. In the past, designers have had to rely upon the fidelity of models found in the Process Design Kit (PDK). For new processes, the models can be incomplete or not fully characterized by the foundry. With Mil/Aero applications, the performance data can be inadequate when designing components for harsh environments. Harsh environments can include extreme temperatures and damaging effects of radiation exposure.
A new methodology for evaluating key parameters to determine the process’s suitability for a particular application is described. The new methodology described incorporates a unique combination of hardware and software to provide extended characterization information in the minimum amount of time and at a greatly reduced cost. The methodology also enables standardization of comparisons of the key characteristics of similar fabrication processes.
The purpose of this paper if to provide information on ProChek™, the comprehensive process mismatch and reliability characterization tool for advanced transistor technologies.
RGI internal document title for reference only: WP_Rapid-Characterization.pdf
For the complete paper, go to:
(Link pending review)