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Digital Avionics Systems Conference, 1999. Proceedings. 18th

Date 1999

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  • Graybox software testing methodology: embedded software testing technique

    Page(s): 10.A.5-1 - 10.A.5-8 vol.2
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    The Graybox Methodology is a full software life-cycle testing methodology used to functionally verify Ada, `C', FORTRAN and assembly language software developed for embedded applications. The Graybox methodology reduces the cost and the time of software development by automatically creating all test unique software. It has been estimated that one line of unique test code is developed for every ten lines of application code (a 10% reduction in SW test time). Previous studies have shown that what used to take two days now takes less than four hours to thoroughly test a unit of software (a 75% reduction in test time). Since the cost of maintaining and upgrading this test-use only code is high, it is simply discarded after testing thereby receiving the name “throw-away” code View full abstract»

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  • Design of pulse width modulation based smart switch controller for automotive applications

    Page(s): 8.C.1-1 - 8.C.1-7 vol.2
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    This paper presents an improved design of a Pulse Width Modulation (PWM) controller for controlling the blower motor in the Heat Ventilation and Air Conditioning (HVAC) applications of an automobile. The design employs a smart switch instead of the conventional power MOSFET. This smart switch is a monolithic device with built-in protection features such as thermal shutdown, linear current limitation, short circuit protection and over-voltage clamp. This switch thus eliminates the protection circuitry required around the power MOSFET. The computer models generated for both the design methodologies (with power MOSFET and with smart switch) in SABER simulation package are presented. These models have been validated against experimental data. The paper contains a comparison of the two design schemes in terms of the size and number of components required View full abstract»

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  • No room for Rembrandt: combining WXR, TCAS, TAWS, FMS, VMS, and CNI on one display

    Page(s): 6.C.1-1 - 6.C.1-8 vol.2
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    This paper describes the System Integration and Cockpit Topology required for Enhanced Situational Awareness by an aircraft crew combining Mission Management (MMS), Flight Management (FMS), Vehicle Management (VMS), and Communication-Navigation-Identification Management (CNI). The inference to be drawn from the title is that this Topology should be specified in a “top down” manner so as to be the same all around the world, and not to be vendor or software specific. A principal problem treated is that all major aircraft systems such as Weather Radar (WXR), Traffic and Collision Avoidance System (TCAS), Terrain Avoidance Warning System (TAWS), FMS, VMS, and CNI have been using the same display color schemes and different data bases which can provide confusion in an integrated system. A radical provision of this approach is that both the pilot and the ground controller can often see the same Situational Awareness display without extensive transmission of data from either location. Also treated are the integration of a millimeter wave radar or radiometer, a course predictor, and a certified database into the Topology View full abstract»

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  • Application of commercial resources to military needs for electronic power sub-systems

    Page(s): 9.A.2-1 - 9.A.2-5 vol.2
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    To reduce the costs of military power supply and distribution systems, the Electronic Power Specification Standardization (EPSS) activities, supported and driven by coalitions of the industry, is developing two interrelated reference documents: (1) Specification Language, and (2) Building Codes. Specification Language imparts integrity to the power system specification process and the resulting products. Building Codes are based on available high-end commercial products, and indicate their expected performance. The EPSS strategy is to provide the rational for the commercial power supply manufacturers to conform to these developing industry standards. Military power supply users will be able to confidently select needed resources from the commercial suppliers that conform to these EPSS standards View full abstract»

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  • RF loading effects of aircraft seats in an electromagnetic reverberating environment

    Page(s): 10.B.5-1 - 10.B.5-7 vol.2
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    Loading effects of aircraft seats in an electromagnetic reverberating environment are investigated. The effects are determined by comparing the reverberation chamber's insertion losses with and without the seats. The average per-seat absorption cross-sections are derived for coach and first class seats, and the results are compared for several seat configurations. An example is given for how the seat absorption cross-sections can be used to estimate the loading effects on the RF environment in an aircraft passenger cabin View full abstract»

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  • Low-cost miniaturized electronics for space application with chip-on board technology-design, manufacturing and reliability considerations

    Page(s): 7.D.1-1 - 7.D.1-7 vol.2
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    The shift in emphasis to smaller, better, and cheaper space systems, resulting from the NASA New Millennium Program (NMP) and similar initiatives in DOD-sponsored programs, demands highly innovative designs that cannot be feasibly implemented using conventional electronic packaging techniques. To meet these broad requirements the APL launched an internal research and development initiative to make significant advancements in electronic packaging technology. Among many miniaturization techniques available for design and development, chip-on-board (COB) based on laminated multichip module technology was selected. The technology utilizes a straightforward design concept, that has been simplified through careful review and testing. In the COB technology, both bare dies and conventional packaged devices are mounted on the same substrate with a special coating to protect the circuits from handling, ground testing, and in-orbit environments. The flexibility of COB packaging techniques helps resolving parts shortage, and last-minute part change problems. This paper summarizes the packaging design, development, and fabrication of two miniaturized space systems-the Command and Data Handling In Your Palm (C&DH IYP) and the Miniaturized Scientific Imager (MSI)-using COB technology. The C&DH IYP is a modular system consisting of multiple individual slices that can implement anything from a standalone Instrument Processor, to a Command and Data Handling system, or the entire electronics needed by a spacecraft. The MSI is a narrow-field-of-view visible imager design with a reflective telescope, a single filter, and a charged-couple device (CCD) detector. We demonstrate that mass and volume reduction of a factor of 10 can be achieved with low-cost COB packaging technology View full abstract»

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  • A product line approach to weapon systems acquisition

    Page(s): 9.A.4-1 - 9.A.4-9 vol.2
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    This paper focuses on the product line approach to weapon systems acquisition and its key features. We emphasize open systems and architectures and the development environment to support the approach. We discuss examples where this approach has produced outstanding results, and we summarize findings that should encourage senior executives and program managers to embrace the concept View full abstract»

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  • Monte Carlo simulation of reverberation chambers

    Page(s): 10.C.1-1 - 10.C.1-8 vol.2
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    This paper describes how to simulate a reverberation chamber using a uniform random number generator and mathematical manipulation. It describes some of the characteristics of a good random number generator, as well as some potential problems. We show how to generate random numbers having any specific distribution, and show how to generate the distributions specific to reverberation chambers. Finally, we show how to introduce common chamber imperfections into the simulations. These imperfections include direct coupling to a sensor, imperfect uniformity, compression, and correlation View full abstract»

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  • Getting more from the scene for autonomous navigation: demo III XUV program

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    The authors have applied a systems philosophy to the computer vision problem, and they have designed a system called O-NAV (Object NAVigation) that can harness all of the computer vision technology to date, and combine these approaches into one integrated system. In O-NAV, no one sub-component bears the burden of the problem. In other words, it is not expected that algorithms alone will solve the computer vision problem. If we choose effective sensing that inherently performs some level of scene discrimination at the phenomenology level, algorithms will be handed a partially analyzed scene before they ever encounter the raw image data. The algorithms have been designed to exploit an optimized processing hardware infrastructure, to maximize computation for the “real-time” application of autonomous robot navigation View full abstract»

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  • Joint tactical radio systems-a solution to avionics modernization

    Page(s): 9.A.5-1 - 9.A.5-8 vol.2
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    The goal of Avionics Modernization Programs (AMP) is to provide a flexible platform that is maintainable and expandable to meet mission requirements of today with defined growth paths to future requirements while maintaining low acquisition and ownership costs. The open architecture and modular construction of the Joint Tactical Radio System (JTRS) provides this path and capability to meet both current radio communications requirements and growth capability needs. The JTRS is defined in terms of its hardware and software architecture. This paper addresses the hardware architecture View full abstract»

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  • Verification tools for embedded robotic electronics

    Page(s): 7.D.3-1 - 7.D.3-7 vol.2
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    The embedded electronics in the Ranger Telerobotic Shuttle Experiment require a system specific verification tool to perform the necessary tests in order to come to a conclusion as to the systems functionality. The ability to create an automated system verification tool is feasible, but is it the most efficient? Is a human needed for making decisions as to the functionality of the electronics, or can we automate this process and eliminate the human from the loop? If an automated verification tool is to be used, what will be its architecture? The following paper will address these issues and evaluate the use of a visual verification tool versus an automated verification tool for the testing View full abstract»

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  • Freeing product line architectures from execution dependencies [avionics software]

    Page(s): 9.C.2-1 - 9.C.2-8 vol.2
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    In 1995, an initiative was launched to assess the potential for reuse of operational flight program software across multiple fighter aircraft platforms, and to define and demonstrate a supporting system architecture based upon open commercial hardware, software, standards and practices. Essential aspects of the resulting component-based logical architecture developed therein have been previously described. The focus of this paper is on selected aspects of the physical architecture resulting from that work. First, this paper briefly restates principle results from the previously published work to set the context for discussion. It then defines the design goals of software physical architecture particularly relevant to product line development and discusses solutions toward achieving these goals View full abstract»

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  • Space integrated GPS/INS (SIGI) navigation system for Space Shuttle

    Page(s): 7.A.4-1 - 7.A.4-8 vol.2
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    This paper consists of a description of the lessons learned and the results of the integration of Honeywell's space-capable Space Integrated GPS/INS (SIGI) navigation system into the Space Shuttle vehicle. The SIGI, as demonstrated during the Shuttle flight test missions, was fully operational during all Shuttle mission phases, ascent, on-orbit, entry, and landing. The SIGI provides three independent navigation solutions (Blended GPS/INS, GPS-Only, and INS-Only) for output at all times. The software upgrades for Space Shuttle include an improved gravity model and blended Kalman filter error states. The SIGI provides a cold start capability to perform an in-space initialization. The SIGI has flown on six Shuttle flight demonstration tests (DTO 700-15). This paper will discuss the performance of the SIGI operation during these flights. These flight test missions have provided the insight into required SIGI software upgrades to make the SIGI more compatible to the existing Shuttle features and interfaces. Flight tests of the SIGI have demonstrated the expected improved performance of an Integrated GPS/INS system as compared to the existing stand-alone GPS and IMU systems View full abstract»

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  • Test and validation of electronic systems

    Page(s): 10.A.1-1 - 10.A.1-7 vol.2
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    Computers are growing in complexity at an ever increasing rate. The ability to properly validate all of the processor's functions is a problem faced by processor manufacturers. A major area for improvement in reducing acquisition time is eliminating the wait for physical prototypes prior to commencement of software test and debug. It is not unusual for this waiting period to account for as much as one-third of the development cycle. Thus the current interest in hardware/software co-design. By overlapping phases of development, co-design brings the test and validation of a system closer to the architectural phase where it is needed most. Early verification that a design meets the customer's requirements minimizes the risk of building a system no one wants. CPU Technology's Behavioral Verification TechnologyTM (BVT) and SystemLabTM provide a means to thoroughly validate complex processors. BVT was invented to address the validation interests of all of the participants in the computer industry. It enables the rapid development of formal instruction-set architecture validation suites for any computer. SystemLab expands beyond hardware/software co-design to the virtual laboratory that consists of virtual prototypes made from software models rather than hardware components View full abstract»

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  • Control laws with hierarchical switch logic to accomodate EME-induced sensor failures

    Page(s): 10.C.3-1 - 10.C.3-4 vol.2
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    In this paper the issue of fault tolerance of flight control systems to sensor failures due to harsh electromagnetic environments is addressed. Severe consequences of these failures can be avoided or at least mitigated to a large degree by using fault tolerant software design. An array of control laws anticipating sensor failures is designed. A hierarchical logic to switch between these controllers is programmed, allowing effective and rapid reconfiguration of the system to accommodate for failed sensors View full abstract»

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  • Formalism helps in describing accidents

    Page(s): 6.D.4-1 - 6.D.4-10 vol.2
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    We analyse the `probable cause' of the 1979 Chicago DC-10 accident using a minimal formalism, and find an omission. The omission is contained in the body of the report. This omission had consequences for the public discussion of this accident, which we show. We conclude that formalism helps in accident reporting by enabling simple consistency and omission checks. We then present a quick overview of our formal method, Why-Because Analysis, which provides the necessary mechanisms and rigor. We consider this to be the engineering of causal reasoning. As is now known from a quarter-century's experience with verification of digital systems, such reasoning engineering is both essential and non-trivial View full abstract»

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  • Depth detection of targets in a monocular image sequence

    Page(s): 8.A.2-1 - 8.A.2-7 vol.2
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    This paper describes an approach for recovering structure of a moving target from a monocular image sequence. Within this paper, we assume the camera is stationary. We first use a motion detection algorithm to detect moving targets based on four heuristics derived from the properties of moving vehicles, maximum velocity, small velocity changes, coherent, and continuous motion. The second algorithm then estimates the distance of the moving targets using an over-constrained approach. We will show a proof-of-concept example from synthetic data. We have applied the approach to monocular image sequences captured by a moving camera to recover the 3D structure of stationary targets such as trees, telephone pole, etc. The experimental results on a monocular image sequence captured in an outdoor environment are also presented View full abstract»

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  • JTRS-an open, distributed-object computing software radio architecture

    Page(s): 9.A.6-1 - 9.A.6-8 vol.2
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    The Joint Tactical Radio System (JTRS) program is a 3-step process to define, standardize, and implement a software defined radio architecture. Step 1 resulted in a baseline architecture definition. In Step 2 the architecture definition will be developed and validated as the Software Communications Architecture (SCA) which will be the basis for future DoD software radios. The SCA is also expected to become the standard for Government and commercial software radios. Step 3 activities will result in procurement and integration of systems and waveforms that are compliant with the SCA and which satisfy individual DoD user requirements. During Step 3, the architecture will continue to evolve in response to new or changing warfighter requirements and technology advancements. The JTRS is defined in terms of its hardware, software, networking, and security architecture. This paper addresses the Software Communications Architecture View full abstract»

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  • A component framework for satellite on-board software

    Page(s): 7.C.1-1 - 7.C.1-10 vol.2
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    This paper advocates a new approach to satellite software design based on object-oriented framework technology and describes early results from a project for the European Space Agency (ESA) to design a software framework for satellite attitude and orbit control systems (AOCS). Frameworks are collections of components with pre-defined cooperations among them. They make architecture (as opposed to mere code) reuse possible. The framework concept is being tested in a redesign of the AOCS software. This paper illustrates it by describing the implementation of telecommand handling, telemetry handling, and operational mode management View full abstract»

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  • Results of the first astronaut-rover (ASRO) interaction field experiment and recommendations for future planetary surface exploration

    Page(s): 7.C.3-1 - 7.C.3-8 vol.2
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    The ASRO project proposes to: (1) identify the operational domains where the EVA astronauts and rovers are complementary and can interact; (2) identify preliminary requirements and recommendations for advanced spacesuits and rovers that facilitate their cooperative and complementary interaction; (3) develop operational procedures and mission scenarios for the astronaut-rover team in the identified domains; (4) test these procedures during field experiments by simulating the exploration of a planetary landing site; (5) train test subject, simulated Earth-based science team, and automated vehicle operator in mission configuration; (6) test the feasibility and utility of adding some automation to the interaction between the astronaut and the rover by providing a stereo vision that tracks the position of the astronaut relative to the rover, and (7) evaluate and understand socio-technical aspects of the astronaut-rover interaction experiment in order to guide future technology designs. Results of the Silver Lake field experiment are discussed View full abstract»

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  • A novel power generation system for ground vehicles

    Page(s): 8.C.4-1 - 8.C.4-10 vol.2
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    The paper presents a new generation scheme that is capable of efficient high electric power as needed for future automobiles. The new system consists of a permanent magnet (PM) alternator, a split winding and a novel electronic voltage regulator. A proof of concept system, capable of providing 100/250 A (idle/cruising) at 14 V, has been built and tested. The results show that this high output is provided at 15-20 percentage points higher efficiencies than conventional automotive alternators, which translates into considerable fuel economy savings. The alternator is also 8 dB quieter and has a rotor inertia of only 2/3 that of an equivalent production alternator, thus avoiding belt slippage. Analysis show that a 48 V system would be even more efficient with up to 5-percentile points improvement and could use power devices with reduced current rating, size and cost View full abstract»

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  • JAHUMS ACTD-a case study in open systems from a technology insertion perspective

    Page(s): 9.B.5-1 - 9.B.5-10 vol.2
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    This paper summarizes efforts within the Joint Advanced Health and Usage Monitoring System (JAHUMS) Advanced Concept Technology Demonstration (ACTD) Program to demonstrate advanced helicopter health and usage monitoring technologies and to validate an open systems approach from a technology insertion perspective. The JAHUMS ACTD technology insertion efforts capitalize on the availability of a commercial health and usage monitoring system (HUMS) that consists of an onboard processing unit, a ground based processor and server, and an enterprise database. A non-proprietary open systems specification for the system provides interface information to support the development of technologies by independent third party providers. Several technology modules are being developed in parallel with the initial fielding of the baseline system and consist of both hardware and software components that will be added to the onboard and ground based systems. It is anticipated that a modular open architecture, coupled with a complementary business architecture, will provide substantial opportunities for technology insertion in both military and commercial HUMS View full abstract»

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  • A comparison of reverberation chamber and semi-anechoic chamber testing for automotive susceptibility

    Page(s): 10.C.2-1 - 10.C.2-7 vol.2
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    This paper describes a set of elementary measurements made to determine the level of correlation that may be expected between susceptibility testing in a reverberation chamber and in an anechoic chamber. The measurements are simple and well defined. A test object was placed in both chambers and illuminated with a test field of 75 V/m. The box was measured with two orientations of the slot, vertical and horizontal. The results show correlation in frequency response between the test methods but not in measured levels induced inside the test box. This lack of correlation is shown to be due to differences in induced currents on the face of the test box View full abstract»

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  • Update of the development of a low cost data acquisition system for the Space Shuttle solid rocket booster program

    Page(s): 7.B.1-1 - 7.B.1-5 vol.2
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    The Space Shuttle has been flying for seventeen years and current NASA plans show it flying for many more years. To support the current and future shuttle flight schedule, portions of the shuttle are being upgraded. One of the areas being upgraded is the avionics on the solid rocket boosters (SRB's). To develop reliable avionics hardware, the environments that they encounter during ascent, descent and water impact must be known. Past environmental data collected did not provide the high fidelity data that is required to fabricate new avionics hardware. This paper summarizes the effort to measure the SRB environments via a commercial off the shelf data acquisition system View full abstract»

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  • A framework for reusable and rehostable software

    Page(s): 8.A.5-1 - 8.A.5-8 vol.2
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    The software content of real-time embedded military weapon systems continues to increase as do the cost and time to develop these systems. Many solutions have been suggested as a means of reducing the cost of software development. Software reuse is recognized as one of the most promising approaches to explore; however, it is a exceedingly difficult strategy to implement. Developing unique solutions to this common need is not cost effective. The Combat Vehicle Operating Environment (CVOE) was initially aimed at providing this common solution. This paper gives the details of the genesis of CVOE and its associated reuse model. It is suggested that the approach developed can be applied more broadly throughout an organization. For this to happen, a comprehensive software reuse and productivity strategy that encourages domain-based reuse and the development of general-purpose products is needed View full abstract»

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