Showing papers presented at "AUTOTESTCON in 2002"

A reference architecture for remote diagnostics and prognostics applications

Abstract: This paper describes a reference architecture for developing and implementing software applications that perform remote vehicle diagnostics and prognostics. The reference architecture incorporates emerging standard server technologies at the application level to ensure portability across a broad range of server platforms and to promote reuse of core application components across diverse end user domains. The core applications include the real-time diagnostics management application, a diagnostic analysis toolset, and an analysis and authoring environment for developing diagnostic/prognostic applications. The diagnostic analysis toolset uses Java-based application components within a common framework to enable a diverse mix of reasoning and rule-based methods to be flexibly integrated within diagnostic and prognostic applications. These same components are also used in the real time server environment for executing diagnostic and prognostic strategies.

Real-time, embedded diagnostics and prognostics in advanced artillery systems

Abstract: This paper explores an integrated modeling and reasoning approach to real-time, embedded diagnostics and prognostics called the Armament Diagnostic And Prognostic Tool (ADAPT). In addition, an approach for using the real-time diagnostic and prognostic information for degraded operation control of armament systems is described. The application focus of this paper is on advanced armament system gun mounts; however, the ADAPT approach has general applicability to a large class of complex systems. It is powered and enabled by the integration of three modeling and reasoning technologies Prognostics Framework (PF) model-based reasoning, Statistical Network (StatNet) modeling, and a time domain gun mount simulation. The model embodied in the PF reasoning is called a fault/symptom matrix, which is a connectivity matrix that represents the linkages of anomalies or faults (rows in the matrix) to observable measurements and the coverage of tests that pass or fail (columns in the matrix). StatNet is a modeling algorithm in the ModelQuest Analyst data mining tool. This algorithm combines the effective 'network of functions' concept in neural networks with proven statistical learning techniques.

Reducing No Fault Found using statistical processing and an expert system

Abstract: This paper describes a method for capturing avionics test failure results from Automated Test Equipment (ATE) and statistically processing this data to provide decision support for software engineers in reducing No Fault Found (NFF) cases at various testing levels. NFFs have plagued the avionics test and repair environment for years at enormous cost to readiness and logistics support. The costs in terms of depot repair and user exchange dollars that are wasted annually for unresolved cases are graphically illustrated. A diagnostic data model is presented, which automatically captures, archives and statistically processes test parameters and failure results which are then used to determine if an NFF at the next testing level resulted from a test anomaly. The model includes statistical process methods, which produce historical trend patterns for each part and serial numbered unit tested. An Expert System is used to detect statistical pattern changes and stores that information in a knowledge base. A Decision Support System (DSS) provides advisories for engineers and technicians by combining the statistical test pattern with unit performance changes in the knowledge base. Examples of specific F-16 NFF reduction results are provided.

Rollout strategies for sequential fault diagnosis

Abstract: Test sequencing is a binary identification problem wherein one needs to develop a minimal expected cost testing procedure to determine which one of a finite number of possible failure sources, if any, is present. The problem can be solved optimally using dynamic programming or AND/OR graph search methods (AO*, CF and HS). However, for large systems, the associated computation with dynamic programming or AND/OR graph search methods is substantial, due to the rapidly increasing number of OR nodes (denoting ambiguity states) and AND nodes (denoting tests) in the search graph. In order to overcome the computational explosion, the one-step or multi-step lookahead heuristic algorithms have been developed to solve the test sequencing problem. In this paper, we propose to apply rollout strategies, which can be combined with the one-step or multi-step lookahead heuristic algorithms to obtain near-optimal solutions in a computationally efficient manner than the optimal strategies. The rollout strategies are illustrated and tested using a range of real-world systems. We show computational results, which suggest that the information-heuristic based rollout policies are significantly better than other rollout policies based on Huffman coding and entropy.

A unified interface for signal-oriented control of instruments and switches

Abstract: The signal-based testing paradigm, which reduces the impact of instrument obsolescence, is typically implemented via software architectures that encapsulate instrument-specific code in signal drivers. The paper describes the design of a signal driver interface and an extension of this design that enables the uniform treatment of instruments and switches. The unified interface supports the control of switches found inside instruments, and the modeling of signal transmission capabilities of switches and signal paths. Its use has the potential to lower software development costs. by reducing the number of different interfaces in Automatic Test Systems.

PXI: the future of test

Abstract: As commercial and military electronic technology evolves, so does the need for more sophisticated, reliable, and cost-effective test equipment. The new PXI platform fills this gap and provides the ultimate test solution for field, laboratory, or manufacturing test applications. This paper discusses the evolution of test that led to the development of the PXI standard and provides technical information of the PXI bus.

Portable maintenance aid instrument pack-improved weapon system diagnostics

Abstract: False removals are costly and add to the logistics tail of every weapon system. Integrating portable maintenance aids (PMAs) and maintenance information systems into the test repertoire can help significantly; however, these solutions do little to augment the information available for system test and diagnosis. Adding conventional test instrumentation under PMA control would provide the additional information we seek; however, these hardware intensive solutions are typically large, heavy and expensive. VXI offers an opportunity to consolidate instrumentation into a convenient package; however VXI modules are not designed to meet the rigor associated with the MIL-PRF-28800 Class 1 environment. Moreover, the majority of VXI products provide a single function. Therefore many VXI modules are required to provide the needed functionality, resulting in an instrumentation package that is large and awkward to use at best and quite often just not useable on the flightline. This paper addresses false removals, the challenges involved in addressing this issue, and the solution that is being implemented on the RAH-66 Comanche Helicopter program. A powerful approach to instrumentation that is both powerful and useable, and the test techniques that have been developed to augment diagnostic capability on the flightline, are described.

Optical switching for automated test systems

Abstract: The proliferation of optical technology in the commercial telecom arena has driven the need to develop cost effective fiber optic component test systems with high throughput rates. As more and more optical technology makes its way into military systems the needs are increasing for general-purpose optical test systems to meet these diverse requirements as well. An understanding of the optical performance parameters of optical switches is needed to design optimal optical switch based test systems for measurement of both active and passive optical component performance. The advantages of using optically switched test architectures to increase productivity, provide greater measurement accuracy and to lower overall test equipment investment are numerous. The general availability of optical switches that meet the required performance parameters, enable the development of cost effective flexible test systems and embedded monitoring systems that can support a wide range of requirements. This paper explores some of the uses of optical switches in test, measurement, and embedded monitoring applications. Optical switch system design options and performance tradeoffs are also discussed in detail. A comparison of modular with stand-alone optical switches is discussed with regard to cost and functionality.

Factory automation systems: Evolution and trends

Abstract: The paper mainly presents the evolution of factory automation and the trends for the next generation factory automation systems, i.e., open systems. Along the dimension of open architecture, it discusses some standardized methodologies involving Linux open source operating system, platform independent Java programming language, systematic object-oriented software engineering, Web-based information publishing, virtual instrument based system configuration, distributed and embedded real-time systems, etc. and their applications in factory automation systems. The resulting open systems are capable of keeping up with the evolving requirements in automation industry and it is expected that the strict use of standards would bring benefits to enterprises in the long sight.

Results using trend analysis for predicting automotive maintenance needs

Abstract: This organization supports the US Army Test Measurement and Diagnostic Equipment Product Manager in a project called ADIP, Army Diagnostic Improvement Program. We provide engineering support by gathering and analyzing data from several vehicles. Such measurements as oil pressure, fuel pressure, compression unbalance, starter current, battery internal resistance, etc, are made. Our aim is to predict changes in these parameters to prevent unscheduled downtime and to fix small problems before they become larger. Explanation of the math used will be given. Use of the requirement tolerance placed as plus or minus bounds around the last measurement and the extrapolated trend line to produce time to exceedance will be described. Using some preliminary data it will be shown how to establish sampling intervals. Using these techniques we have found that for the data available the sample interval is about four (4) months. A number of problems that tend to obscure trends have been identified, studied, and solutions found. A few examples will illustrate some of these. Since the trend analysis is based on historical data from individual vehicles the results apply to that vehicle only. As more vehicles from that family are studied certain family traits emerge hence one may establish general family features.

PXI for military test applications

Abstract: As PXI is gaining in-roads into military test applications, systems integrators start using the PXI platform as the core of military testers for manufacturing, service, and field test. This paper discusses two such applications. The first is a production tester used in the manufacturing of the Longbow launcher and the second is a portable field tester for the Maverick Missile System.

An integrated view of test and diagnostic information standards

Abstract: In this paper, we discuss the technical issues related to defining a coordinated view of integrated diagnostic information. Our objective is to define a process and modeling framework for solving the information integration problem. The process discussed is based on formal modeling methods that have been used for years in various contexts but rarely combined. Specifically, the approach applies a "component" orientation to the problem and draws heavily from the discipline of information modeling.

Strategies for mitigating risk related to the obsolescence of HP 8566/68 spectrum analyzers in ATE systems

Abstract: The Hewlett-Packard 8566 and 8568 were the first RF and microwave spectrum analyzers offering remote control and data transfer through the GPIB interface. These analyzers have been widely deployed in automated test equipment (ATE) systems and the majority of units produced since introduction 24 years ago are in active use. These instruments were discontinued five years ago, and Agilent Technologies will suspend support for them this year. This situation exposes ATE system managers to higher levels of risk than might be apparent. This paper outlines risk areas and presents a range of mitigation actions that affected managers might take. In describing those actions, a new option for HP 8566/68 programming code compatibility is introduced and discussed.

Building test applications using timing and triggering with PXI

Abstract: The PXI platform provides sophisticated synchronization capabilities for automated test applications. This paper provides a technical overview of triggering and synchronization capabilities of PXI, including the PXI Trigger Bus, the Star Trigger Bus, and the back-plane clock. The test applications of triggering and synchronization are discussed and demonstrated, including: synchronization of multiple digitizers/scopes to simultaneously sample multiple channels; synchronization of a scope (or multiple scopes) to a source to accomplish time domain measurements of the DUT response to stimulus; position based measurements (digitizers synchronized to counter/timers); synchronization of a DMM to a switch to access multiple test nodes when the DUT has settled to a steady state; and synchronization of motion control with image acquisition.

Overview and applications of the IEEE P1451.4 smart sensor interface standard

Abstract: With the goal of promoting the development and adoption of smart transducers, the IEEE 1451 family of smart sensor interface standards defines a set of standardized interfaces for different categories of smart sensors and smart actuators. One member of this family, the IEEE P1451.4 standard, defines a mixed-mode interface that combines that traditional analog sensor signal with a digital interface that enables self-identification of the sensor for plug and play operation. This self-identification is provided by a transducer electronic data sheet (TEDS) that is stored within the transducer. In addition to explaining the components and mechanisms of IEEE P1451.4, the paper describes the implication of plug and play sensors for test and measurement systems. The paper also documents an example implementation of a computer-based data acquisition system that exploits the plug and play sensor concept.

XML data representation for testing automation

Abstract: XML (eXtensible Markup Language) technologies seem to offer solutions for a wide range of automated testing issues. In fact, these technologies are very promising to address scalability and interoperability among distributed software applications and to facilitate reuse ensuring data coherency, completeness and reliability. In this paper we discuss the use of XML for representing the whole set of information regarding configuration and classification data involved with a software environment for test automation. Thus we introduce a case study where the effectiveness of this approach was used to face the automated testing of telecommunication device.

Intermediate level maintenance Fibre Channel testing

Abstract: Fibre Channel (FC) has been identified as the next avionic communication architecture to complement, and in some cases, replace an over-burdened MIL-STD-1553 architecture. Despite the availability of FC commercial standards, a. common maintenance approach has not surfaced among the multitude of military avionic manufacturers. As a result, there is no clear definition of intermediate level maintenance testing of FC communication architectures as the definition is applied to military avionic equipment. This paper identifies the FC intermediate level maintenance challenges and formulates a viable solution for intermediate level testing that does not exist today. This maintenance solution transfers commercial practices into a military environment by establishing a basic support capability through the use of standardized commercial equipment and processes and then modifies those processes to build a generic, military test methodology.

The IVI open architecture driver specifications

Abstract: This paper describes the IVI open architecture standard which provides the basic driver standardization that makes IVI drivers easy to learn and use. It provides an overview of the open architecture specifications and describes how they impact the tasks of system developers.

Test and measurement equipment adopts computer industry standards

Abstract: Test-and-measurement engineers involved in measurement, automation and product test can significantly benefit from rapid developments in the general computer industry. Relevant computer-standard technologies, applied to the test, measurement and automation industry's solutions, instruments and systems, bring a wealth of vital, new and innovative capabilities to the users of such equipment. Use of computer-standard technologies also results in reduced equipment costs, dramatically improved ease of use, consistency between instruments, simpler and more powerful software solutions, and accelerated equipment time-to-market.

Modular test architectures for the aerospace industry

Abstract: This paper lays the ground work for a common test platform architecture being adopted by a number of organizations in the aerospace industry. Test engineers realize that integration is not a one time event. This paper discusses an architecture based on a modular hardware and software platform that ensures design freedom and the ability to upgrade test systems without rearchitecting the entire test system. Additionally engineers in diverse applications such as structural test, turbine/engine test, avionics, environmental screening, and hydraulic actuator test can now use common elements of design and implementation hence saving their organizations money and development time.

DiagML - an interoperability platform for test and diagnostics software

Abstract: The integration of diagnostic software and test execution environments developed by different vendors requires a common data exchange format. The paper describes a new format based on XML, called the Diagnostic Modeling Language (DiagML). This format is currently used for integrating software applications developed by DSI International and TYX Corporation. The design-to-test process supported by DiagML is illustrated through a diagnostic application for a simple analog circuit.

Adopting IVI: an incremental approach [Interchangeable Virtual Instruments]

Abstract: Interchangeable Virtual Instruments (IVI) instrument driver technology offers the test system developer many benefits over existing implementations. As instruments become obsolete, or as newer higher performance or lower cost instruments become available, the significant investment expended on the Test Program Set (TPS) will not be impacted. Lockheed Martin Information Systems (LMIS) is encouraged by the promise IVI brings to Automatic Test Equipment (ATE). We are committed to the principle of isolating test software from the variability of a specific instrument. We have demonstrated this commitment by incorporating an IVI-like interface in our automated test systems several years ago when IVI was not adequately defined. As a result, we have seen first-hand the benefits it brings to non-recurring engineering expenses of new systems. Today, IVI is still not fully defined; its major drawback being the limited number of approved instrument classes. The slow speed of bringing an instrument class to fruition may be the major obstacle of adopting IVI in a test system. This paper identifies our approach for an incremental adoption of IVI into current, future, and legacy programs as it becomes more defined.

Synthesis of complex signals on test equipment

Abstract: A traditional signal definition exhaustively lists every attribute and condition that it was thought the signal could possibly have. However, it is often the case that we are only interested in controlling a limited number of signal attributes and conditions. The traditional method is inflexible in this respect, leading to problems when trying to map different capabilities in a signal standard, as required for ATP (Automated Test Program) portability. In this paper we consider a concept called a Signal Graph to define a model of a single, complete signal. Each component in the Signal Graph identifies a feature or behavior that our signal will exhibit. The Signal Graph is a mechanism whereby we can define a set of features that we require, which can then be mapped onto a series or collection of suitable resources (e.g. algorithm, PC card, bus instrument, etc.). We show how complex, 'user defined' signals can be created and then mapped onto real hardware to provide a portable ATE (Automatic Test Environment) signal description, which can be used on a variety of ATEs. This paper draws upon IEEE standard SDTD (Signal Definition and Test Description) standard to utilize common components and interfacing techniques and shows how a single test description can be used for both simulation and execution.

Optimizing automated testing for high throughput

Abstract: Throughput in automated testing is a critical issue, especially at the maintenance level. Some general rules and approaches, when used with an analysis of the total test requirement, can often substantially reduce test time. New programming environments and new (to test equipment) interface standards such as Ethernet, when available, may provide significant throughput improvement in a test system. Agilent's recent work with manufacturers in the wireless industry has helped validate a variety of approaches to optimize test throughput for transceiver manufacturing. We have found that very significant gains can be realized from only a modest investment. This paper describes successful practices and techniques for optimizing test throughput, and gives specific quantitative examples of the improvements that have been achieved.

Operating, monitoring and controlling plant components over cyberspace

Abstract: In recent years, nearly every industry has increasingly implemented computer based measurement, instrumentation and automation technologies to control, operate, and/or monitor various plant components of industrial equipment. This has also resulted in a paradigm shift from analog to digital technologies that are suitable for communications over the Internet, Web or networked computer systems. This paper presents a methodology for remote operation and monitoring of plant components through the Internet/Web. The Internet interfacing technologies have been examined through an experimental setup used at Fort Valley State University to perform remote experiments via the Internet. The setup is a motor-generator station that can be fully operated, monitored and controlled by computer systems using Virtual Instrument programs written in LabVIEW. It also features on-line capabilities that allow users to fully operate and monitor it remotely through the Internet. The paper also addresses typical technological concerns and challenges regarding safety and security measures as well as real-time operation.

CASS upgrade COSSI-a systematic approach to incorporating NxTest technology into legacy military ATE

Abstract: The Consolidated Automated Support System (CASS) Upgrade Commercial Operations and Support Savings Initiative (COSSI) is a multi-year cooperative development agreement to insert commercial off the shelf (COTS) based NxTest technology into the existing US Navy CASS test station to provide operations and support (O&S) cost savings which was started in August 2000 and is scheduled to finish this year. This paper discusses the unique programmatic and technical challenges faced when incorporating new technologies into legacy military ATE.

A design pattern to encapsulate measurement uncertainty in reusable instrumentation modules

Abstract: A method of encapsulating and propagating measurement uncertainty information in modular instrumentation systems is described. The technique is simple to implement and fully compliant with international best practice. Measurement uncertainty is a fundamental aspect of any measurement system and is currently difficult to manage when systems are subjected to configuration changes. The technique could provide a significant step forward in maintaining the integrity of complex systems.

Implementation of Prognostics Framework on Navy Battle Group - Automated Maintenance Environment (BG-AME) and Total Ship Monitoring (TSM) Programs

Abstract: This paper will describe how the Prognostics Framework model-based reasoning tool was used by the Navy under the Battle Group - Automated Maintenance Environment (BG-AME) and Total Ship Monitoring (TSM) Programs to provide real-time condition monitoring and prognostics of ship systems, and provide mission capability assessments to commanders.

IVI comes of age: an overview of IVI specifications with current status

Abstract: IVI stands for Interchangeable Virtual Instruments. The IVI Foundation was formed in 1997 and is a consortium founded to promote standard specifications for programmable test instruments The IVI Foundation focuses on the needs of users who build high performance test systems. By building on existing industry standards such as VXIplug&play driver concepts, the Foundation's goal is to deliver specifications that simplify interchangeability, provide better performance and maintainable test programs. To date, only a few IVI drivers have been available. In the past year, the IVI Foundation finished a major revision of it's architecture, and has released a blizzard of specifications, increasing its IVI Class specification by 80%, and dramatically improving the consistency and quality of released drivers. The DOD has expressed major interest in IVI's success. With the recent successful completion of the current set of specifications, the DOD has expressed interest in becoming involved in defining the next set of Class Specifications. The NxTest Working Group lists IVI as a key technical element, and the DOD has recently requested that the IVI Foundation consider Electro Optical equipment for their next set of Class Specifications. A Working Group has been formed to more clearly define this activity.

Ultrahigh reliability US Army missiles and munitions

Abstract: Provides an overview of U.S. Army requirements necessary for missiles and munitions to survive and operate in extreme environments with ultrahigh reliability. Long-term storage of assets, exposure to harsh environments, and requirements for high reliability with minimum field checks are significant concerns for Army missiles and munitions. These concerns warrant investigation into new and advanced techniques that provide health monitoring and prognostics capability, as well as robust design. In the past, missiles and munitions were commonly stored for long periods of time within the various military depot environments. In the present Army, however, missiles and munitions can expect deployment into a theater of operations and subsequent return to stocks for a potential future deployment. These deployments are expected to occur several times during an asset's life cycle, with extremes being experienced for each deployment due to handling, transportation, and theater storage. Therefore, the potential detrimental affects which a missile and/or munition will likely encounter must be understood and accounted for in its design and fielding so that its war fighting capability and readiness can be assured. Ultrahigh reliability of weapon systems is a critical requirement for the transformed Army to quickly enable a lethal and decisive battle force. This presentation will define ultra-reliability as it relates to missiles and munitions. Approaches to achieving ultra-reliability will be discussed, including joint efforts by the Department of Defense and the Department of Energy in modeling materials aging phenomena.