Michael Dewey

Modernizing legacy Automated Test Systems for DoD depots

Department of defense (DoD) maintenance depots face a growing challenge regarding legacy Automated Test Systems (ATS). These systems, which are critical to ensuring mission success, are increasingly difficult to maintain and repair as well as being costly to modernize or replace. According to the General Accounting Office, the DoD has estimated that they will spend billions of dollars to modernize their ATS inventory, much of which was acquired in the 1970s and 1980s [1]. One of the maintenance depots is Tobyhanna Army Depot (TYAD) and is in a similar situation with it legacy test systems. The aging testers at TYAD are becoming increasingly out of date and more difficult to support. When the testers do not work properly, maintenance can suffer and readiness can be adversely affected. This paper reviews the requirements and issues associated with depot ATS equipment and will present a technical strategy for the modernization of ATS at TYAD.

Applying high performance digital instrumentation for video test applications

Video imaging and high performance displays have become common-place in a broad spectrum of products - ranging from consumer to industrial including military-aerospace applications. With the advent of new digital video standards, new demands are being placed on the test systems and instrumentation that are used to test and support these complex systems. In the past, test systems have relied upon ldquoboxrdquo video generators to evaluate monitors and video processing equipment. However, with the advent of sophisticated imaging sensors and processors and the transition from analog to digital based high-definition video, more advanced techniques and instrumentation are needed. Todaypsilas test techniques are incorporating high performance digital instrumentation in conjunction with software and specialized ldquovideo adaptationrdquo hardware to support the generation and analysis of high definition video signals. This paper provides an overview of the capabilities and requirements needed to support the testing and maintenance of video imaging, sensors, and processors that employ digital video interfaces.

Addressing legacy ATE system requirements with PXI

Beginning in the late 1960s, proprietary ATE systems were deployed by a wide range of customers for the functional test and verification of high value, mission critical products including board & box level avionics, depot level test & repair of armament and avionics electronics, and communications / satellite subsystems. These test systems are now obsolete, however the products (and their derivatives) originally tested on these platforms are still in use and need to be maintained. Consequently, there is an on-going need to either maintain these obsolete systems or migrate the applications and the legacy systems capabilities to a modern test platform. The paper provides an overview of how the PXI architecture, and associated instrumentation and software can provide the basis for a modern functional test platform that can effectively support both legacy ATE functionality as well as future functional test needs.

Next generation test system architectures for Depot and O-level test

For over 30 years, ATE has been a key resource and tool for the maintenance and repair of electronic systems, subsystems and board level assemblies deployed on a wide range of military-aerospace systems. ATE has been relied upon to maintain and support electronic assemblies for avionics, weapons systems, and communication systems. In addition, repair logistics and the “up-time” demands for these systems have resulted in the need for repair / support strategies that shorten the repair loop. For the U S Marine Corp, the need to minimize this repair loop is acute and has resulted in the adoption of a maintenance / repair strategy that employs Depot - level test capabilities which can also be deployed at the field or O-level. This paper discusses how next generation test architectures can address this on-going requirement for portability, performance and cost effective test solutions which address both Depot and O-level test needs.

Legacy test systems — Replace or maintain

Test platforms age, the components within the test systems degrade, become obsolete and wear out over time. Manufacturing companies must continuously evaluate the expected lifespan of their test equipment and determine the risk and tradeoffs associated with replacing the equipment vs. maintaining the equipment. Both industry and government entities continually struggle with how to best evaluate and address the issues of aging test equipment and systems. This paper reviews the various options available to test engineers when faced with replacing or maintaining a test system. Specifically, the manufacturing / test community must evaluate the consequences, risks and costs associated with each choice: 1. Do nothing and continue to maintain equipment until equipment failure. 2. Rejuvenate equipment by replacing components / instruments. 3. Replace existing equipment with modern automated test equipment. 4. Outsource manufacturing and test of product to a supplier. To help quantify the decision making process the use of an evaluation tool can help analyze the factors that influence the “replace or maintain” question. Each of the options listed above carries with it its own list of questions that must be addressed. These questions are encoded into the tool with responses then interpreted and results collated with user historical data, providing the test engineer with quantifiable and meaningful data for evaluating the cost of replacing or maintain factory test equipment. The following sections detail how this tool can be developed and utilized as part of the “replace or maintain” decisional process.

PXI-based, high performance, high density switching architecture

Virtually all ATE systems employ a switching subsystem in order to route test system resources to multiple test points on the UUT. The challenge for any switching subsystem is multi-dimensional and involves many considerations / trade-offs including footprint, performance, flexibility, maintainability, and reliability. Additionally, if the application needs to address legacy test needs, there can be the additional challenge to support not only current and future switching requirements, but also legacy test requirements. This paper reviews current switching architectures employed today and discusses the benefits / limitations of current COTS offerings. The paper also reviews the switching requirements associated with addressing high complexity / high performance functional test applications and how the development and implementation of a PXI-based switching architecture can meet these requirements.

Incorporating optical test capabilities into a depot test platform

This paper reviews how an existing test platform that supports a variety of missile launcher systems; LAU 7, LAU 88, LAU 117, LAU 127, LAU 128, and LAU 129, was modified to address support for Paveway laser guided bomb kits. Specifically, support for the Paveway system required the addition of an optical test bench as well as adding additional simulation and test capabilities to accurately simulate laser targets and to measure laser detection signals. The modular design of the existing TS-217 test system afforded test engineers the ability to augment the existing test platform such that both LRU and SRU level test capabilities were part of the complete solution. Additionally, by incorporating an innovative optical bench with a solid-state target, a complete functional simulation of the weapon was achievable including testing of operational limits. The complete paper will detail the updates incorporated into the test system which were needed to provide a test solution that offers full functional verification of the weapon. Additionally, a review of the optical bench implementation will be discussed including the incorporation of a novel solid state target simulation system.

Creating automated test and repair solutions with advanced diagnostics and ATE software

Todays complex electronic assemblies employ sophisticated and advanced automated test solutions to verify functional performance - both at the time of manufacture and for depot repair scenarios. Providing go / no-go test solutions are routinely created for all types of electronic assemblies. However, the task of diagnosing todays failed UUTs or systems is not a process that is easily automated. Older generation and less complex electronic assemblies may have employed automated diagnostics such as guided probe but with the complexity of todays electronic assemblies, coupled with long program development time, automated diagnostics has largely been abandoned by OEMs and Depot test / repair facilities. However, with products becoming increasingly complex and with the extended life-cycles of many mil-aero and commercial systems and platforms, the need for automated diagnostics remains in high demand, and this demand continues to increase - particularly at the Depot level where the ability to efficiently and accurately diagnose and repair products is acute. This paper discusses how advances in diagnostic tools can be incorporated with ATE software to create a comprehensive test environment supporting, go / no-go, as well as automated diagnostics. By integrating the diagnostics design knowledge with the test station, test confidence is taken to the highest level and, in the event of a UUT failure, rapid identification of the failed component is now embedded in the test station. Todays high tech test systems provide excellent confidence testing; however, the extended time required to troubleshoot and analyze a faulty UUT complicates support logistics and drives up over all support / maintenance and Unit Production Costs (UPC). Repairing todays complex UUTs requires a high skill level to isolate the failure to the root cause component. By employing an advanced UUT diagnostics design methodology which provides an enhanced understanding of the units test capability, coupled with the design knowledge of the UUT, the capabilities of an existing test station can be extended to included advanced diagnostics.

Incorporating advanced instrumentation capabilities into a PXI digital multimeter instrument

The use of card modular instrumentation for ATE systems offers test engineers many benefits - including lower acquisition costs, a more compact system footprint, and higher performance when compared to “box based” ATE architecture. In particular, upgrading to the PXI architecture can decrease both the physical and budgetary footprints, while still meeting the overall test requirements. However, for T&M instrument suppliers, incorporating the features and capabilities associated with advanced instrumentation into the PXI form-factor can present several design challenges, particularly in the areas of volume / real estate, noise, power consumption, and measurement stability. Additionally, these demanding requirements can be further challenged when the instrument is required to operate beyond the “normal” temperature range associated with commercial instrumentation. This paper discusses the requirements and techniques used to develop a PXI-based, high performance DMM. A review of the required performance parameters is presented along with an analysis of the alternative design methods employed in order to achieve the necessary performance capabilities without compromising the overall capabilities of the hardware. Areas covered in this paper include a discussion of design techniques which includes the use of multi-function circuitry to reduce overall volume requirements, the conversion of purely analog circuitry into a mixed signal format to reduce volume and power requirements, minimizing power supply noise when replacing a mains-based power supply with isolated and non-isolated DC/DC circuitry and the requirement to operate over an extended temperature range. Additionally, a review of the overall mechanical design with attention to the need to accommodate the noise and airflow considerations associated with the PXI architecture is discussed.

Consolidating test resources for avionics production test - requirements and applications

The manufacturing and test of avionics products for military and commercial aircraft presents a unique set of requirements and challenges. Historically, the development and deployment of production test systems for avionics products such as aircraft data acquisition and recording systems, navigation and communication products, and aircraft network systems have been addressed on a product specific basis - resulting in a variety of test platforms and solutions with little test system commonality and technology. Additionally, this lack of test system commonality and the requirement to maintain legacy products with long product life cycles results in increased maintenance and logistics costs for manufacturing and support test. Consequently, the adoption of a common test platform can offer producers of avionics products lower test costs, improved test resource utilization, and the flexibility to support both new and legacy products. This paper reviews the requirements and the implementation of a common test platform and environment that offers a high level of efficiency, supports the implementation of routine test processes, offers reusability, and allows the consolidation of test resources to facilitate the collection of reliability data and test results.