Showing papers presented at "AUTOTESTCON in 1993"

Workflow management combined with diagnostic and repair expert system tools for maintenance operations

Abstract: The authors present an integrated framework for effective management of maintenance operations that addresses two key problems: the shortage of resources; and the performance differences between the individual available resources, and specifically, the human resources. Software tools are proposed for these two problems. W-6 assists in improved cost-effective utilization of the available resources. That is, assigning the right person, to the right job, at the right time, and with the right resources. AITEST and OnDoc contribute in increasing the productivity and work quality of each individual service person. Software integration is not centered on sharing of data because most of the data and knowledge required by one tool is not required at all by the others. The proposed EPI (External Program Interface) tool implements integration that is centered on the concept of workflow management. The different software systems exchange messages that are characterized by control-passing and by division of labor, with relatively small amounts of data being shared. A case study of a large depot facility where this framework has been implemented is described. >

Virtual instruments: The future of ATE is here today

Abstract: Virtual Instruments (VI, also called instruments-on-a-Disk) is the next stage in the evolution of ATE. VI fundamentally changes the paradigm of how ATE is designed, built, fielded, supported and procured. The core of the VI concept is the idea that most instruments can be implemented in software, supported by a bare minimum of low-cost, commercial off-the-shelf hardware. The effect of VI is that the hardware cost of ATE is reduced dramatically, along with its life cycle cost. Flexibility is enhanced, for adding new instruments is reduced to adding software. In some cases, the VI approach allows measurement accuracies that considerably improve the current state-of-the-art. New stimulus and measurement techniques can be implemented using VI to measure the previously unmeasurable, and generate what was previously extremely difficult to generate. This paper describes the VI concept and one embodiment of VI: a flightline electronic warfare tester. That embodiment implements more than 12 complex instruments in less than a single VXI chassis. >

A neural network approach to hierarchical analog fault diagnosis

Abstract: A novel technique involving a neural network for efficient hierarchical fault diagnosis of analog circuits and systems is presented. The fault clustering property of the neural network is utilized to conceptualized the fault equivalence and BC (behavioral condition) reduction at higher levels. It is also shown that fault diagnosis can be done at any desired level and the precision of the diagnosis can be controlled during the fault dictionary generation stage. This technique can be applied to diagnose systems irrespective of their domain of operation as long as they can simulated. The proposed methodology was verified using an OTA-C low pass filter. >

Virtual instruments in VXI

Abstract: VXI is an exciting and fast-growing platform for modular instruments on plug-in boards. Because VXI combines a modern computing architecture with a sophisticated instrumentation environment, it makes possible the construction of unique new instrument components and measurement methodologies. This paper discusses the term virtual instrument, a term that has become a buzzword in the VXI industry. Historically, architectural limitations have resulted in hard boundaries between vendor-defined instruments and user-defined functionality in an instrumentation system. The author discusses instrument connectivity and software frameworks for building virtual instruments, and also describes the key architectural and philosophical issues that are changing because of VXI. The purpose is to show how these changes create a new generation of instrumentation tools that empower users, rather than vendors, to define the functionality of instruments. >

DARTS: An enabling technology for concurrent engineering

Abstract: Advanced technology includes techniques, materials, and architectures which provide real advantages over those currently used. Such technology has not replaced the technology currently being used for one or more of the following reasons: (1) it is generally unknown, (2) it does not have all the necessary input and output interfaces, (3) it is incompatible with established standards and practices, or (4) it needs to be implemented. The US Army Test, Measurement, and Diagnostic Equipment Activity Advanced Technology Office's job is to identify such technologies and remove the impediments to their usage. This paper describes one of the Advanced Technology Office's success stories, the Diagnostic Analysis and Repair Tool Set, or DARTS. >

Time stress measurement device use for on-board diagnostic support

Abstract: Time stress measurement systems have been developed to support fielded and emerging systems. This electronic link between the system and maintainer is non-instrusive to the prime mission equipment and provides information as to the cause of failure events in flight. This paper provides a brief background into several programs where TSMD system integration is in progress in mature systems such as the B-1B radar, emerging research and development efforts such as iBITSM, and new platforms. The Time Stress Measurement Device serves on-equipment to capture, pre-process, store, and communicate fault or intermittent data to support flight-line or depot diagnostic tools. Off-equipment elements of the time stress measurement system include data collection, data management, and trend analysis. Time stress measurement has evolved over the last ten years from environmental stress data gathering to advanced Built-In-test-Equipment which supports fault isolation on-equipment and Re-TOK reduction off-equipment. >

Printed circuit board diagnosis using artificial neural networks and circuit magnetic fields

Abstract: Testing of electronic systems using conventional testing methods has become more difficult and costly as these systems have become more complex and compact. Conventional testing methods and systems often require lengthy analysis to define testing strategies. These test systems may require lengthy test periods, complex stimulus and measurement instrumentation as well as complicated fixturing. The results are often ambiguous and require further interpretation. This paper presents an exploration of a non-intrusive test method based on interpreting changes in the magnetic field close to a printed circuit board (PCB). Currents moving between devices on the PCB produce these magnetic fields. Changes of the PCB operational status due to faults cause changes in the associated magnetic field pattern that can be interpreted by artificial neural networks (ANNs) for fault identification. An apparatus to collect magnetic field measurements is described along with some problems of collecting data. Typical magnetic field patterns for known-good and faulted PCBs are presented. Possible extensions of the method are discussed. >

Integration of neural network technology in automated fault diagnosis equipment

Abstract: The use of artificial neural networks (ANNs) for identification of pump faults is described. A description of how ANN technology can be incorporated into automated test equipment (ATE) is also presented. >

Converting test requirements into test program sets

Abstract: A new approach is described for converting a minimal set of test requirements and a set of test vectors into a working test program set (TPS). A test requirements file (TRF) expresses all of the necessary information for testing the logical functions and electrical and switching performance of a device-under-test. The TRF and the test vector files are processed automatically to produce the TPS. Test requirements are audited for correctness or reasonableness, and some types of tests can be generated automatically if their specifications are omitted. >

Full operational electronic warfare testing at the flightline

Abstract: The current mix of EW flightline testers depend almost exclusively on parametric and functional testing that are inadequate to properly test modern EW suites. They are all based on hardware-intensive architectures that inherently promote high life cycle costs. There is now an alternative: a mix of operational, functional, and parametric testing in a virtual instrument-based architecture. AlliedSignal's FAST project demonstrates that all of the concepts discussed in this paper can be implemented now with low risk. Those who are developing the requirements for future flightline EW testers may take advantage of its dramatically improved performance and lower life cycle cost. >

Virtual instruments for use in test systems development

Abstract: SYTRONICS employed the use of modeled instruments during the recent development of the Engine Monitoring and Control System (EMCS) completed for the US Navy in which the engine was modeled and simulated for the purposes of developing, testing, and verifying the Engine Test Cell system. This simulated engine provided a virtual instrument for use with the development of the Test Cell. The Test Cell was originally developed for testing the T-406 (V-22) engine at the Navy's Cherry Point Depot. Currently, the Test Cell is in use at this facility testing other engines. This paper addresses the practical issues of using such virtual instruments during the development of test systems. It also evaluates cost savings incurred through this development methodology and describes future capabilities and advantages of using virtual instruments for other development and test systems. >

A generalized algorithm for bounding fault detection probabilities in combinational circuits

Abstract: With the ease of incorporating a linear feedback shift register (LFSR) within a chip for generating pseudo-random sequence of binary vectors, random pattern testing is popular as a built-in self test (BIST) scheme for combinational circuits for stuck at faults. A combinational circuit is said to be random pattern testable if a certain fault coverage can be achieved with certain confidence when a randomly chosen input pattern sequence of length equal to or less than a fixed number (dictated by practical constraints) is applied to the inputs. In order to determine if a design is random pattern testable it is necessary to examine the fault detection probability of each fault. The exact determination of fault detection probabilities of the modeled stuck at faults in a combinational circuit is an NP complete problem. In this paper, an algorithm for computing bounds for the fault detection probabilities in linear time and which requires almost no memory is introduced. >

Test design compilers complement top down ASIC design

Abstract: To help the test engineer and the ASIC designer implement testable designs, a set of design tools, known as Test Design Compilers, have been developed to complement a top down design approach. These tools allow test functions to be incorporated and simulated in the earliest design specifications while requiring a minimal effort by the designer. The test compilers generate synthesizable behavioral models that can then be ported to a number of simulation and synthesis environments via the VHSIC Hardware Description Language (VHDL). This paper describes the test compilers that have been developed and implemented into a top down ASIC design environment. The design environment is described, along with the top down approach being used. Next, the test compilers are described along with example applications of the test produced by the compilers. >

Applications of concurrent engineering

Abstract: Over a decade ago, design-to-test entered the electronics industry as an expected savior for reducing test development costs and schedules. While conceptually simple, many companies experienced problems using such a simple approach. Today, concurrent engineering and integrated product development (CE/IPD) are the new industry buzz words. CE/IPD do not represent a single idea or methodology; rather they encompass several methodologies, many of which have been around for a number of years. This paper presents the CE/IPD methodologies used by two companies to improve product and test quality and reduce product development time. While the focus of the CE/IPD effort in each case was in the design and test area, each company used a different combination of methodologies to achieve their goals. >

The multicriterion nature of diagnosis

Abstract: Developing diagnostic strategies is a difficult task, complicated by the multicriterion nature of diagnosis. Sequencing and evaluating tests, as well as performing subsequent diagnosis, are difficult in and of themselves, and achieving accurate diagnosis becomes an ambitious goal. Several new diagnostic tools can compute accurate decision trees using many types of assumptions, thus increasing analytical power. This increased power allows the consideration of the optimization of diagnostic strategies by following several different approaches. They also allow the comparison of the various tools available. This paper provides a framework for developing diagnostic strategies or decision trees according to multiple criteria. These criteria and decision trees fall into three broad categories - preprocessing criteria, optimization criteria, and postprocessing criteria. The authors also discuss guidelines for comparing diagnostic strategies for differing criteria. Interactions between many of these criteria make comparisons difficult or invalid; therefore, the authors provide rules for equivalence as prerequisites for making valid comparisons. >

Embedded diagnostic system design using an automated diagnostic tool set

Abstract: This paper describes the underlying concept and application of an innovative approach for developing an embedded system diagnostics capability integral to a prime system architecture. The approach is predicated on the use of an automated diagnostic tool set. This tool set enables the prime system designer to design both an embedded and off-line diagnostic capability concurrently with the prime system design. Using the tool set, the designer performs trade-offs and generates a run-time diagnostic software module. The discussion of the attributes and operation of the Automated Diagnostic Tool Set focuses on its application to a modern day submarine ship control system. >

Future technology thrusts for ABBET standardization

Abstract: For the past four years a subcommittee has been working on a set of component standards under the Institute of Electrical and Electronic Engineers (IEEE) Project Authorization Request (PAR) 1226 to develop a set of standards under the name Ada Based Environment for Test (ABET). In November 1992 the name was changed to A Broad Based Environment for Test (ABBET) reflecting a much larger charter. ABBET is a base standard as well as a combination of component standards. The ABBET committee has spent a considerable amount of effort in adapting the standard test program set (TPS) language from a descriptive language of the Abbreviated Test Language for All Systems (ATLAS) to the programming language of Ada. It has defined an interface in a standard language that can be compiled using commercial off-the-shelf (COTS) compilers. The committee has also defined interfaces at lower levels that may be used individually or in combination in automated test systems (ATS). This paper explores some of the areas where future ABBET standardization effort should be placed to benefit the automated test community. These areas include product description, test strategies as well as test object models and a graphical user interface for test objects. >

Microelectronic component testing using circuit modeling

Abstract: Microelectronic components testing and analysis is greatly enhanced through automated circuit modeling Southwest Research Institute (SwRI) applies automated circuit modeling consistently to reduce the cost and time of performing circuit analysis and testing Through circuit modeling, a graphical display with performance results are provided to assist the engineer in both troubleshooting microelectronic problem circuits and/or circuit design Circuit modeling allows circuits to be analyzed on paper, thus reducing circuit board stress with regards to boards that appear to have problem areas Also, circuit modeling identifies possible design problems before board prototypes are developed The application of circuit modeling should be considered to reduce the cost and time to perform microelectronic component analysis and testing >

ATE technology trends

Abstract: ATE instrumentation has moved from unique designs to standard rack-based instruments, and are now being re-tooled into instrument-on-a-card form factors. The VXI and MMS standards are having as profound an effect on instrumentation as the IEEE-488 bus did in the 1970's. This paper explores current state-of-the-art ATE hardware and software. It focuses on trends in test technology and their effect on future ATE. The paper addresses specific application areas with potential for international industrial involvement. >

What is CALS all about

Abstract: Computer-Aided Acquisition and Logistic Support (CALS) is fast becoming a way of doing business. This concept, which was developed by the DOD, permits transfer of data between dissimilar computer systems. CALS is defined by a set of standards which are evolving. CALS is also moving into the commercial sector with more companies evaluating the concept as a method of saving time and money. >

Enhancing mission effectiveness through technology insertion: Advanced boresight equipment-A tri-service solution

Abstract: The Advanced Boresight Equipment (ABE) program was established to evaluate current boresight requirements for the Army, Navy, and Air Force and develop a common boresight unit for all fixed wing and rotary wing aircraft. Current boresight equipment for all three services is heavy, bulky, cumbersome, and requires excessive time to use. In addition, each airframe has unique boresight equipment with unique logistics, training, and support requirements. The ABE design provides a solution to current equipment shortcomings. ABE is a state-of-the-art, electrooptical angular measurement system capable of aligning weapons, sensor platforms, and visible and far IR optical systems to an accuracy better than 0.5 milliradian (mrad). The ABE is smaller, lighter, and easier to use than current systems. It also provides increased measurement accuracy and repeatability. This will result in increased readiness through increased mobility, decreased Operations and Support (O&S), and decreased manpower requirements. >

Integrating logic simulation and dependency modeling

Abstract: Simulatable logic models are used for design and test generation. Dependency models are developed independently to analyze inherent testability characteristics and generate test strategies for diagnosis. This paper describes a set of translation tools that convert logic models into dependency models. These tools reduce both the manual effort required and the chances of undetected errors, as well as streamline configuration management. >

CASPER An expert system approach to TPS cost management

Abstract: CASPER, Cost, Assets, Schedule Prediction, and Evaluation Routine, is an expert system design to provide the TPS Program Manager with a sounding board for project estimating and planning. The fundamental design of CASPER can also be applied to manually estimated projects, since the system is based on sound program management principles. This paper discusses the challenges of TPS Program Management and provides insight into parameter interaction and quantification. It also shows how these parameters can be brought together to provide a set of sensible, real-world-based tools for effective application of sound Program Management principles to TPS development. >

Enhancing mission effectiveness through electro-optical systems readiness: IFTE CTS-EOA system requirements

Abstract: The US Army has identified a lack of standard, general purpose, reconfigurable Automated Test Equipment (ATE) at the On-System Direct Support (DS) maintenance level. This lack was further identified as a deficiency in the Electro-Optics (E-O) testing area. The Integrated Family of Test Equipment (IFTE) Contact Test Set (CTS) Electro-Optical Augmentation (EOA) will address this requirement, as well as reducing proliferation of system specific test equipment. The EOA will provide a standardized means of testing all E-O sensor systems in the field directly on the weapon platform. The EOA must be a field qualified, survivable test set that meets the test requirements for 45 Line Replaceable Units (LRUs) from 17 weapon platforms. This paper discusses the operational requirements of the EOA, including system level requirements and sensor system test requirements. >

Extension of TISSS test methodology from chip level to board level for improved transportability and decreased life-cycle costs

Abstract: This paper discusses an implementation of a set of tools designed to improve the supportability and transportability of board level Test Program Sets (TPSs) to multiple test environments. The Tester Independent Support Software System (TISSS) was tried and proven sufficient to test advanced tactical fighter (ATF) complex digital line replaceable modules (LRM). The proposed methodology is an extension of the TISSS philosophy for component level testing in which computer aided design (CAD) designer data is extracted, formatted into generic Institute of Electrical and Electronic Engineers (IEEE) standard formats, translated and postprocessed into tester specific TPSs. This new TPS re-host method will use tools derived from TISSS, Commercial-Off-The-Shelf (COTS) packages, and will be supplemented by some Rome Laboratory customized software tools. The aim of this effort is to demonstrate to the depot maintenance repair community a better approach to TPS development and re-hosting versus conventional methods in terms of reduced costs, time and improved efficiency. >

Navy and joint service missile testing-A management update

Abstract: The shrinking defense budget is applying increasing pressure on the armed services for standardizing ATE. While standardization of ATE for avionics and ground systems is well established, the world of missile systems is still proliferate with Special Test Equipment. If newer missile system designs are to survive, there needs to be a concentrated effort for commonality of test equipment. Process action teams are formulating plans that promote common test philosophies and standardized test equipment among the services. The Navy's standardized automated test system, Consolidated Automated Support System, CASS, was originally targeted for avionics support, but is now expanding to embrace standardization of missile testing. The newest CASS configuration, the guided munitions Common Test Station, moves CASS into the all-up round missile support role and paves the way for multi-service commonality. This paper discusses the management and technical challenges in developing a common test solution and the capabilities the Common Test Station offers as a standardized missile tester. >

AEGIS ORTS - The first and future ultimate integrated diagnostic system

Abstract: This paper discusses the implementation of a structured built-in-test system designed over 20 years ago to support availability of the AEGIS Weapon System. Many of the techniques and concepts which it used are applicable today, forming a basis upon which to apply current technology advances and integrated diagnostic concepts. The evolving result, given in the spirit of OPNAV Instruction 4700.7J - Maintenance Policy for Naval Ships, is that existing operational readiness test systems can be upgraded, not only to be more effective but also to be the core in implementing maintenance systems for an entire ship. >

Electronic performance support systems

Abstract: Electronic Performance Support Systems (EPSS) are computer-based, multimedia systems that are a key to enhancing mission effectiveness in the 90's. Multimedia systems provide for the integration of visual-intensive data in the form of digital video as well as vectorized, colorized graphics with the standard text and line-graphics normally found in maintenance data. EPSS-based maintenance systems allow captured expert knowledge to be accessible on-demand, and provides for each of the users to see the maintenance data in the form most appropriate for the individual's background. With EPSS, system readiness is improved significantly by minimizing downtime through: (1) just-in-time learning to reduce training time, which increases maintenance personnel availability; (2) quick and accurate diagnostic analysis, which reduces false repair rates; (3) visual-based documentation, for consistent adjustment and repair, and (4) rapid update of technical data, to ensure the latest technical information is available. >

Description of the consolidated automated support system (CASS) electro-optical subsystem (EOSS)

Abstract: The CASS EOSS has been developed to provide the Navy an automated test capability for electrooptical (EO) sensors. Previous test methods required highly skilled personnel who are completely familiar with a particular EO sensor. These manual test methods required extensive test times and often involved subjective acceptance criteria. The CASS EOSS provides capability for evaluation of visible and infrared sensors, laser transmitters, receivers, trackers and multi-sensor boresight. The system is capable of performing these measurements in a rugged shipboard environment. All of the tests are performed without the use of a display or any operator intervention. This enables lower skill level personnel, with the assistance of the Test Program Set (TPS), to perform maintenance and repair on EO sensors. This results in reduction of maintenance cost with EO sensor performance maintained at a higher level in comparison to manual test methods. This paper provides a brief overview of the test capability and the evaluations performed by the CASS EOSS. >

Data collection in a two level maintenance environment

Abstract: Increased emphasis is being placed on fielded weapon systems to monitor their logistic status using built-in-test (BIT). There is a strong requirement in a two level maintenance environment (Organizational and Depot) to have immediate access to in-flight operational data. This paper describes a logistics tracking and analysis system for collection, analysis, and distribution of parametric and logistics data. And, it also describes how this data enhances the test, maintenance, and repair functions performed in a two level maintenance environment. >