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A potential correlation between OH* chemiluminescence and exhaust NO concentration is investigated to pursue a simple diagnostic technique for measurements of NO cycle-to-cycle fluctuations. Previous investigations of NO formation in a direct-injection gasoline engine have indicated that there may be a correlation between the concentration of NO and OH* chemiluminescence. Shortcomings of this work, namely phase-locked measurements, were overcome in the present study by using highspeed imaging capability to obtain chemiluminescence within the entire engine cycle and from entire engine cylinder volume. Cycle-resolved NO exhaust gas detection were performed synchronously with the chemiluminescence measurements on an optical spark-ignited engine with spray-guided direct-injection. A quartz cylinder liner, head and piston windows provide optical access for a highspeed CMOS camera and image intensifier to capture OH* images.

The feature of offered algorithm is that it allows, without record and analysis of the display diagram, to estimate a running cycle of a diesel engine parameters which characterize ecological and economic performances. The mathematical model described in report allows to determine connection of coefficient of filling, pressure and temperature of air boost, factor of excess of air with effectiveness ratio of combustion and contents of soot in exhaust gas and to take into account this connection at a choice initial data for control fuel feed or for elaboration of diesel engine dynamic model. The algorithm incorporated, for example, in the microcontroller of an electronic fuel feed controller allows analyzing the sensors data and theoretically determine of smoke amount in the exhaust gases for chosen cycle of fuel feed. The restriction of smoke is possible by criterion dD/dGT, where D - contents of soot in exhaust gas and GT - fuel cycle submission under the program-adaptive schema.

The effects of image size on perceived distance have been of concern for convex rearview mirrors as well as camera-based rear vision systems. We suggest that the importance of image size is limited to cases-such as current rearview mirrors-in which the field of view is small. With larger, richer fields of view it is likely that other distance cues will dominate image size, thereby substantially diminishing the concern that distortions of size will result in distortions of distance perception. We report results from an experiment performed in a driving simulator, with static simulated rearward images, in which subjects were asked to make judgments about the distance to a rearward vehicle. The images showed a field of view substantially wider than provided by any of the individual rearview mirrors in current systems. The field of view was 38 degrees wide and was presented on displays that were either 16.7 or 8.5 degrees wide, thus minifying images by factors of 0.44 or 0.22.

Some of the best teaching methods are laboratory courses in which students experience application of the principles being presented. Preparing young engineering students for a career in the automotive industry challenges us to provide comparable opportunities to explore the dynamic performance of motor vehicles in a controlled environment. Today we are fortunate to have accurate and easy-to-use software programs making it practical for students to simulate the performance of motor vehicles on “virtual” proving grounds. At the University of Michigan the CarSim® vehicle dynamics simulation program has been introduced as such a tool to augment the learning experience. The software is used in the Automotive Engineering course to supplement homework exercises analyzing acceleration, braking, aerodynamics, and cornering performance. This paper provides an overview of the use of simulation in this setting.

Advances in camera and display technology have increased interest in using camera-based systems for all rear-vision functions. The flexibility of camera-based systems is unprecedented, and raises the possibility of providing drivers with fields of view that are very different from, and potentially much better than, those of conventional rearview mirrors. Current fields of view are based on a combination of driver needs and the practical constraints of mirror systems. In order to make the best use of the greater flexibility offered by cameras, a reassessment of drivers' needs for rear vision is needed. A full reassessment will require consideration of many factors. This paper offers a preliminary analysis of one of those factors: the visual workload involved in using rear-vision systems with single versus multiple displays.

Advances in electronic countermeasures for lane-change crashes, including both camera-based rear vision systems and object-detection systems, have provided more options for meeting driver needs than were previously available with rearview mirrors. To some extent, human factors principles can be used to determine what countermeasures would best meet driver needs. However, it is also important to examine sets of crash data as closely as possible for the information they may provide. We review previous analyses of crash data and attempt to reconcile the implications of these analyses with each other as well as with general human factors principles. We argue that the data seem to indicate that the contribution of blind zones to lane-change crashes is substantial.

Simulation of human motions in virtual environments is an essential component of human CAD (Computer-aided Design) systems. In our earlier SAE papers, we introduced a novel motion simulation approach termed Memory-based Motion Simulation (MBMS). MBMS utilizes existing motion databases and predicts novel motions by modifying existing ‘root’ motions through the use of the motion modification algorithm. MBMS overcomes some limitations of existing motion simulation models, as 1) it simulates different types of motions on a single, unified framework, 2) it simulates motions based on alternative movement techniques, and 3) like real humans, it can learn new movement skills continually over time. The current study evaluates the prediction accuracy of MBMS to prove its utility as a predictive tool for computer-aided ergonomics. A total of 627 whole-body one-handed load transfer motions predicted by the algorithm are compared with actual human motions obtained in a motion capture experiment.

Workstation design is one of the most essential components of proactive ergonomics, and digital human models have gained increasing popularity in the analysis and design of current and future workstations (Chaffin 2001). Using digital human technology, it is possible to simulate interactions between humans and current or planned workstations, and conduct quantitative ergonomic analyses based on realistic human postures and motions. Motion capture has served as the primary means by which to acquire and visualize human motions in a digital environment. However, motion capture only provides motions for a specific person performing specific tasks. Albeit useful, at best this allows for the analysis of current or mocked-up workstations only. The ability to subsequently modify these motions is required to efficiently evaluate alternative design possibilities and thus improve design layouts.

When structures may have dynamic instability complex eigenvalue analysis is a useful tool to predict it. Although the accurate prediction itself is significant, it is also crucial to obtain sensitivity of unstable eigensolutions in order to eliminate instability efficiently. Since the mathematical relationship between stiffness matrix and design variables may seldom be found in reality, finite difference method has been typically used to approximate the sensitivity. The novel way to accurately calculate the sensitivity is developed without implementing finite difference method. This paper shows the advantages of analytical sensitivity analysis compared to other methods for choosing the most important components' eigenvalues. It also provides necessary amount of frequency shift for each chosen components' eigenvalue to eliminate unstable eigenvalues.

Night vision enhancement systems (NVES), which use infrared (IR) cameras, are designed to supplement the visibility provided by standard headlamps. There are two main NVES systems: active, near infrared (NIR) systems, which require an IR source but give a complete picture of the scene in front of the driver, and passive, far infrared (FIR) systems, which do not need an IR source but only enhance relatively warm objects (such as people and animals). There are three main display alternatives: a head-up display (HUD) superimposed on the direct view of the road, a HUD just above the dashboard but separated from the direct view, and a conventional display somewhere in the dashboard. This paper analyzes what a NVES should do to improve night visibility based on night crash statistics, driver vision and visibility conditions in night driving, driver tasks and behavior, and the options offered by various technological approaches. Potential problems with using NVES are also discussed.

The increasing availability of camera-based displays for indirect vision in vehicles is providing new opportunities to supplement drivers' direct views of the roadway and surrounding traffic, and is also raising new issues about how drivers perceive the positions and movements of surrounding vehicles. We recently reported evidence that drivers' perception of the distance to rearward vehicles seen in camera-based displays is affected not only by the visual angles subtended by the images of those vehicles, but also by the sizes of those images relative to the sizes of the displays within which they are seen (an influence that we have referred to as a framing effect). There was also evidence for a similar, but weaker, effect with rearview mirrors.

High-intensity discharge (HID) headlamps have several advantages over tungsten-halogen headlamps, including greater light efficiency (lumens per watt) and longer life. However, from the safety point of view, the primary attraction of HID headlamps is that, because they produce more total light, they have the potential to provide more useful illumination to the driver. At the same time, there are concerns with the effects of HID illumination on perception of the colors of important objects and glare to oncoming traffic. This paper reviews research evidence that we have accumulated over the past 14 years concerning the potential benefits and drawbacks associated with the use of HID headlighting. We conclude that the evidence strongly supports the use of well-designed HID headlamps.

The importance of eye-to-display distance for distance perception in rear vision may depend on the type of display. At least in terms of its influence on the effective magnification of images, eye-to-display distance is almost irrelevant for flat rearview mirrors, but it is important for convex rearview mirrors and for other displays, such as video displays, that create images closer to the driver than the actual objects of interest. In the experiment we report here, we investigate the influence of eye-to-display distance on distance perception with both flat rearview mirrors and camera-based video displays. The results indicate that a simple model of distance perception based on the visual angles of images is not very successful. Visual angles may be important, but it appears that relationships between images of distant objects and the frames of the displays are also important. Further work is needed to fully understand how drivers might judge distance in camera-based displays.

This analytical study examined the potential benefits of applying two embodiments of adaptive lighting to the U.S. and European low-beam patterns: curve lighting that involves shifting the beam horizontally into the curve, and motorway lighting that involves shifting the beam vertically upward. The curve lighting simulations paired 240-m radius left and right curves with a horizontal shift of 10°, and 80-m radius curves with a horizontal beam shift of 15°. The motorway lighting simulations involved upward aim shifts of 0.25° and 0.5°. For both curve and motorway lighting, changes in both seeing and glare illuminance were considered. Market-weighted model year 2000 U.S. and European beam patterns were used. We conclude that curve lighting, as simulated here, would substantially improve seeing performance on curves for both types of beams. On right curves (but not on left curves) there would be an increase in disability glare for oncoming traffic.

This study was designed to provide photometric information about current U.S. and European high- and low-beam headlamps. The sample included 20 headlamps manufactured for use on the 20 best-selling passenger vehicles for model year 2000 in the U.S., and 20 headlamps manufactured for use on the 20 best-selling passenger vehicles for model year 2000 in Europe. The vehicles sampled represent 49% and 47%, respectively, of all vehicles sold in the U.S. and in Europe. The lamps were purchased directly from vehicle dealerships. The photometric information for each lamp was weighted by the sales figures for the corresponding vehicle. The results are presented both in tabular form for the 25th-percentile, the median (50th-percentile), and the 75th-percentile luminous intensities, as well as in graphical form (for the median luminous intensities), both for high- and low-beam headlamps (from 45° left to 45° right, and from 5° down to 7° up).

Although biomechanics models can predict the stress on the musculoskeletal system, they cannot predict how the muscle load associated with exertion is perceived. The short-term goal of the present study was to model the perception of effort in lifting and reaching tasks. The long-term goal is to determine the correlation between objective and subjective measures of effort and use this information to predict fatigue or the risk of injury. Lifting and reaching tasks were performed in seated and standing situations. A cylindrical object and a box were moved with one hand and two hands, respectively, from a home location to shelves distributed in the space around the subject. The shoulder and torso effort required to perform these tasks were rated on a ten point visual analog scale.

Interference between physical objects in the workspace and the moving human body may cause serious problems, including errors in manual operation, physical damage and trauma from the collision, and increased biomechanical stresses due to movement reorganization for avoiding the obstacles. Therefore, a computer algorithm to detect possible collisions and simulate human motions to avoid obstacles will be an important tool for computer-aided ergonomics and optimization of system design in the early stage of a design process. In the present study, we present a method of modifying motions for obstacle avoidance when the object intrudes near the center of the planned motion. We take the motion modification approach, as we believe that for a certain class of obstacle avoidance problems, a person would modify a pre-planned motion that would result in a collision to a new one that is collision-free, as opposed to organizing a totally unique motion pattern.

A formulation that accounts for manufacturing variability in the analysis of structural/acoustic systems is presented. The methodology incorporates the concept of fast probability integration with finite element (FEA) and boundary element analysis (BEA) for producing the probabilistic acoustic response of a structural/acoustic system. The advanced mean value method is used for integrating the system probability density function. FEA and BEA are combined for producing the acoustic response that constitutes the performance function. The probabilistic acoustic response is calculated in terms of a cumulative distribution function. The new methodology is used to illustrate the difference between the results from a probabilistic analysis that accounts for manufacturing uncertainty, and an equivalent deterministic simulation through applications. The probabilistic computations are validated by comparison to Monte Carlo simulations.

New developments in the use of two-dimensional displays to supplement driver vision have made it more important to understand the roles that various distance cues play in driver perception of distance in more conventional ways of viewing the road, including direct vision and viewing through rearview mirrors. The current study was designed to investigate the role of binocular distance cues for perception of distance in rearview mirrors. In a field experiment, we obtained data to estimate the importance of binocular cues for distance judgments under conditions representative of real-world traffic. The results indicate that, although binocular cues are potentially available to drivers, these cues probably play little or no role in distance judgments in rearview mirrors in normal driving situations.

This study was designed to provide photometric information about current European low-beam headlamps. The sample included 20 low-beam headlamps manufactured for use on the 20 best-selling passenger vehicles for calendar year 1999 in 17 European countries. These 20 vehicles represent 47% of all vehicles sold in these countries. The lamps were purchased directly from vehicle dealerships, and photometered in 0.25° steps from 45° left to 45° right, and from 5° down to 7° up. The photometric information for each lamp was weighted by 1999 sales figures for the corresponding vehicle. The results are presented both in tabular form for the 25th-percentile, the median (50th-percentile), and the 75th-percentile luminous intensities, as well as in graphical form (for the median luminous intensities).