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Automotive audio systems require signal processing to address losses of spatial rendition of stereo and multichannel sources due to off-centerline listening and the proximity of cabin walls where the speakers are located. The digital signal processing is optimized for each vehicle type and audio option by skilled tuning engineers. They spend the majority of their tuning time on spatial issues when preparing a vehicle. One reason for this is that, until now, there has been no measurement of imaging performance. Engineers have relied on the indirect measures of arrival delay, spectrum and their own hearing to balance the several speakers likely to be contributing to perceived direction, distance and ambience. This paper describes a new module for a measurement system widely used in automotive audio. In addition to assisting the tuning engineer, the system documents audio performance in Tonal Balance, Maximum Output, Distortion, and now, Spatial Rendition.

A loudspeaker's low frequency parameters can be accurately estimated by measuring individual components without the need to assemble them into a working unit. Using this development approach, much time can be saved by optimizing one component at a time rather than building an entire speaker for each iteration. To do this, one must be able to measure the relevant physical characteristics of each component (the electro-mechanical parameters). It is also necessary to be able to predict electro-acoustic performance from the electro-mechanical parameters.

The introduction of Low Observable (LO) technology on combat aircraft has produced a leap in aircraft survivability but also raised some difficult questions. How do you quantify survivability, and since new technology tends to be expensive, how LO does an aircraft need to be to accomplish its mission? This paper will show how low observability dramatically improves combat aircraft survivability by reducing an air defense's ability to detect, track, intercept and destroy an LO aircraft. Important aircraft signatures that can be detected such as radar, visual, infrared and intentional emissions are discussed in detail as well as methods to reduce those signatures. LO and mission planning tactics' impacts on threat system capabilities are examined and examples of LO aircraft penetration of a notional hostile air defense are shown.

With increasingly stringent legislation controlling vehicular emissions being introduced, efficiency gains in combustion engines continue to be desirable to OEMs. Reducing FMEP provides one such route and with piston-cylinder interactions accounting for around 40% [1 & 2] of a typical engines frictional losses warrants research directed at improvements. Though developments are being driven by numerical techniques, there is still the need for robust experimental data to evaluate these models. One of the measurable parameters which offers a direct link between simulation and ‘the real world’ is lubricant film thickness within the contact. For over half a decade, various techniques have been used to monitor film thickness but can broadly be split into those exploiting the thickness related electrical, optical or acoustical properties of the lubricant.

To achieve high-accuracy measurements of fuel consumption in testing on natural gas vehicles, a method for measuring the absolute value of fuel consumption by the gravimetric method using certificated reference weights and an electric platform scale has been developed. By performing a flow-meter test and a chassis dynamometer test using the gravimetric method, the measurement accuracy of the value of fuel flow rate and fuel consumption obtained by the fuel flow meters, carbon balance method, and air-to-fuel ratio method was evaluated. As a result, a highly accurate method for measuring fuel consumption in chassis dynamometer tests has been confirmed.

In this study we have developed a new measuring method of the hypoid gear tooth profiles manufactured by Gleason's gear cutting machines. Based on analysis of the tooth profiles of hypoid gears, the angular position of the ideal gears and the position of the measuring probe contacting the tooth surface at the measuring location are computed first. Actual tooth surface measurements are made with a three-coordinate measuring machine to detect deviation of the actual position of the probe from the ideal position and the deviation of the tooth surface is then evaluated. The method gives us not only the profile of a tooth section but also the profile on the whole tooth surface. Some experimental results have proved that the measuring method is useful.

The biological effects of ionizing radiation in space has been the subject of considerable concern even before humans actually began the exploration of space. Advances in Biotechnology now make it possible to monitor mutations in humans. Here we report the study of five Russian cosmonauts with considerable space flight experience and four trainees. Although the levels of mutation in these subjects were higher than observed in age-matched Western controls, no significant difference in either mutant frequency nor mutational specificity was observed. We conclude that Low Earth Orbit radiation does not produce detectable levels of mutation in human subjects.

The use of Selective Catalytic Reduction (SCR) for NOx emissions control has resulted in a new challenge for the emissions measurement community. Most SCR systems require injection of urea or ammonia into the exhaust stream. Residual ammonia present in vehicle exhaust can have deleterious effects on NOx analyzers using chemiluminescent detectors (CLD). Ammonia can poison converter catalysts in CLD NOx analyzers and may react with NO2 across the converter. Both of these issues lead to erroneous NOx measurements, as well as increased maintenance costs and downtime. This paper will describe the development and use of a low-cost, simple ammonia scrubber that can easily be integrated into sampling systems and requires little change in test cell maintenance procedures. Validation results show the scrubber to have capacity sufficient to last for a full day of testing of typical vehicles.

In the environmentally conscious world we live in, auto manufacturers are under extreme pressure to reduce tailpipe emissions from cars and trucks. The manufacturers have responded by creating clean-burning engines and exhaust treatments that mainly produce CO2 and water vapor along with trace emissions of pollutants such as CO, THC, NOx, and CH4. The trace emissions are regulated by law, and testing must be performed to show that they are below a certain level for the vehicle to be classified as road legal. Modern engine and pollution control technology has moved so quickly toward zero pollutant emissions that the testing technology is no longer able to accurately measure the trace levels of pollutants. Negative emission values are often measured for some pollutants, as shown by results from eight laboratories independently testing the same SULEV automobile.

New instruments and new measurement concepts continually evolve in support of programs to reduce operator noise exposure and produce noise emission. The purpose of this paper is to review new equipment and new measurement practices which can assist in the direction of programs to develop quieter vehicles. Opportunity is taken to also discuss the closely associated field of whole-body vibration.

A gravimetric particulate measurement system, which extracts samples isokinetically from raw exhaust, is presented to quantify the particulate mass stored in diesel particulate filters. The purpose of this measurement system is to facilitate the study of wall-flow filter behavior at different particulate load levels. Within this paper, the design considerations for the particulate measurement system are detailed and its operation is described. The accuracy of the measurement is examined through a theoretical error analysis and direct experimental comparison to the differential weight of a diesel particulate filter. Experimental results are also presented to validate the ability of the system to maintain the isokinetic sampling condition.

During the last fifteen years, the marine industry has seen results of a technological revolution in the form of diagnostic tool development. With application of computers and oscilloscopes, certified service technicians can tell just about any characteristic of an engine…whether it be wear rates from the internal frictional surfaces of the engine components or performance characteristics of the total propulsion system. Extensive research and development work has been done in the area of marine performance analysis. A system has been developed that utilizes all of the diagnostic tools developed over the years in a systematic approach to make a definitive measurement of the entire propulsion system. This program evaluates the fuel system, cooling system, propeller, transmission and the air/intake and exhaust system. In marine vessel operation, it is vitally important to have a properly matched propulsion system.

This paper presents a general method for measuring plant-wide industrial energy savings and demonstrates the method using a case study from an actual industrial energy assessment. The method uses regression models to characterize baseline energy use. It takes into account changes in weather and production, and can use sub-metered data or whole plant utility billing data. In addition to calculating overall savings, the method is also able to disaggregate savings into components, which provides additional insight into the effectiveness of the individual savings measures. Although the method incorporates search techniques and multi-variable least-squares regression, it is easily implemented using data analysis software. The case study compared expected, unadjusted and weather-adjusted savings from six recommendations to reduce fuel use. The study demonstrates the importance of adjusting for weather variation between the pre- and post-retrofit periods.

Accurate measurements of productivity and quality are essential for balancing workload, creating predictable schedules and budgets, and controlling quality. Traditional software development processes include well-established methods for measuring productivity and quality. These include Lines of Code (LOC). With the introduction of Model-Based Design, organizations require a different measure of the software development process.

Energy standard ISO 50001 will require industries to quantify improvement in energy intensity to qualify for certification. This paper describes a four-step method to analyze utility billing, weather, and production data to quantify a company's normalized energy intensity over time. The method uses 3-pararameter change-point regression modeling of utility billing data against weather and production data to derive energy signature equations. The energy signature equation is driven by typical weather and production data to calculate the ‘normal annual consumption’, NAC, and divided by typical production to calculate ‘normalized energy intensity” NEI. These steps are repeated on sequential sets of 12 months of data to generate a series of ‘sliding’ NEIs and regression coefficients. The method removes the effects of changing weather and production levels, so that the change in energy intensity is a sole function of changing energy efficiency.

Work is expended by the deformation of a motor vehicle in an accident. Relating this work to changes in kinetic energy or change in velocity during impact is an important step in reconstructing accident speeds and crash severity. The calculation of such work will depend upon the nature of the vehicle deformation and certain properties of the vehicle. Discussion of vehicle crush properties expressed for use in mathematical models of collisions has appeared in recent literature; however, very little has been described of a measurement protocol for the quantitative description of vehicle deformation. This paper discusses such a protocol and presents details based on experiences encountered with its evolution and use in certain field accident studies. The purpose is to promote discussion of damage measurement protocol with the expectation of improving such protocol as well as expanding its use.

UNKNOWN factors regarding fuel-injector performance have handicapped diesel-engine combustion studies in the past. Rate at which fuel is introduced into the engine cylinder and quantity of fuel available for combustion at any instant were two basic unknowns hindering advance. This paper presents results of an investigation aimed at measuring fuel-injector performance in a firing engine, simultaneously with obtaining pressure-time curves and other needed data. Method and instrumentation developed covers three characteristics of injector performance: 1. Rate of fuel injection. 2. Fuel-injection timing. 3. Injection pressures. The method results in obtaining more comprehensive data, but has the disadvantage of added complexities requiring skilled handling.

Reliability is an important performance parameter often referred to subjectively in terms such as “high reliability” but seldom measured or verified. This results from one or both of the following reasons: ○ Measurement of reliability occurs over a long time span. Measuring reliability in the user environment can require months or years of operating history; whereas, acceleration, turning radius, and other performance parameters can be measured with a short term controlled experiment. Without immediate results, diligence in data monitoring often deteriorates until data value is questionable. ○ There is a false notion that complex statistical techniques are necessary to make useable estimates of reliability levels and patterns. A process is proposed in this paper whereby users, distributors, or manufacturers can quantitatively measure reliability in the user environment.

An improved metric for the reliability of spot-weld nondestructive tests is proposed. The traditional metric uses rates of false calls and misses obtained by comparing results of the nondestructive test with subsequent destructive determinations of button size. Such error rates, however, are not determined by the characteristics of the nondestructive test alone but are confounded by the distribution of weld quality of the welds input into the test. The only meaningful way to characterize the reliability of the nondestructive test, independent of the weld distribution, is by quantifying the uncertainty in the test’s predictive power.

In this paper we discuss avoiding failure modes due to lack of robustness. It is proposed that robustness should be measured through a parameter in a transfer function, as opposed to a signal-to-noise ratio. A case study on engine starting is used to illustrate the idea.