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An introduction to vehicle steering response dynamics is followed by a discussion of the influence of pneumatic tyres on driver subjective ratings concerning vehicle steering and handling characteristics. An empirical study investigating driver sensitivity to the effects of low profile radial-ply and standard radial-ply tyres is then described. It was found that the subjective ratings of ordinary drivers could be systematically related to objective measures of vehicle directional response. Most important in affecting favourable ratings were short lateral acceleration and yaw rate response times, and higher levels of control gain for these parameters. Low profile radial tyres were rated relatively more favourably than standard radials, mainly in respect of a combination of steering “feel,” stability on dual carriageways, and roadholding on straight roads and motorways (freeways).

This paper describes a newly developed microcomputer-based drowsiness warning system, which detects changes in the driver's alertness through his steering behavior. In developing this system, we first quantified several levels of alertness based on such physiological factors as brain activity and blinking. Tests were then conducted in which drivers fell into different degrees of drowsiness. Using the quantified alertness levels, we defined the “drowsy driver” and found unique steering patterns that could not be seen in normal driving. These patterns were entered into the memory unit of the microcomputer. When the sensor built into the steering wheel detects a drowsy steering pattern, the microcomputer recognizes the driver's drowsiness and activates a buzzer to warn the driver. In this paper, the process of determining the alertness levels is explained, along with the steering characteristics of the drowsy driver.

An instrument is described that permits the measurement of scattered light on windshields in cars in full daylight. It presents the intensities of the scattered light in the form of a diagram and calculates two indices, which can be associated with the most prominent types of wear, i.e., impact of small stones and wiper damage. The instrument is easy to operate and permits inspection of a large number of windshields in a short time. Measurements on 300 vehicles indicate a linear increase in wear due to impact of small stones with mileage and a more-than-linear increase of wiper damage. Vehicles of identical mileage can have very different values depending on the type of use. It is also examined how the different amounts of wear as characterized by the measured indices affect the ability of test persons to see and recognize objects on the road.

This paper addresses the risks of motor vehicle involvement in highway accidents. Such risks are determined from U.S. accident experience in the past 10 years. Risks are analyzed as a function of vehicle type, car market class, make, nameplate, and model year for accidents of various types and various severities. Both absolute risks, per unit exposure, and relative risks are addressed. The influence of many exposure variables is examined and necessary adjustments, to a common set of exposure conditions, are made. The control variables for this purpose are: calendar year, car age driver's age, sex, and alcohol involvement; time and place of travel: and various roadway characteristics. Adjusted risks are reviewed versus major characteristics of cars as implied by make, nameplate, and model year. Single driver accidents and rollovers. Whether pre- or post-impact, receive special attention due to their risk sensitivity to car class.

Improvement of pedestrian safety is considered a priority in crash injury protection. Dummies, however, are not able to give a humanlike and repeatable impact response in pedestrian tests. The Biomechanical Laboratory of ONSER in France and the Department of Traffic Safety of Chalmers University in Götheborg, Sweden have designed a new dummy for pedestrian testing. The dummy is designed according to the latest available anthropometric and biomechanical data. Its symmetry around the vertical axis allows repeatability for the kinematic and injury parameters. It allows a measurement of uncommon biomechanical parameters related to injury mechanisms. Its leg is instrumented to determine the distribution of forces and momenta applied to the leg.

Many physically handicapped drivers have difficulties in using ordinary car controls, and modifications need to be made to their vehicles. A review of the types of adaptations and equipment that are available for this in Europe has identified the principal aspects that need to be considered in their design. For safety and ease of use, it is important to match the characteristics of a control conversion to the driver's capabilities, taking into account the location and mode of operation of the control, together with the operating forces and the range of movement. Many of these adaptations are highly individual, and it is also important to encourage innovation and flexibility in design to increase the possibilities for severely disabled people to obtain the mobility accepted as the norm by the rest of the population. Modern technology permits the use of sophisticated control systems, and a high degree of power assistance can be provided on steering and brakes.

Head-neck injuries occur frequently in pedestrian and occupant automotive accidents even at relatively low speeds. This paper describes the results of laboratory impact experiments using human cadavers in pedestrian/vehicle impacts and lateral-to-medial head impacts at well-known, controlled speeds. Cerebral trauma, with and without skull fracture, is discussed as a function of impact configuration and velocity. Cervical spine and cord injuries are also discussed with regard to the same parameters. Data presented include impactor mass and velocity, head acceleration measurements, complete autopsy and dissection results, and the clinical evaluation of the effect on a person of the observed trauma. Eighteen cadavers have been exposed to lateral-to-medial head impacts by two mechanisms.

This paper summarizes the results of Phase 1, Concept Definition, of the AATD program and identifies the reasons such a new test device is needed. The following areas are addressed: 1) injury priority from accident data; 2) current dummy design, use, and potential improvements; and 3) technical characteristics and design concepts for a new AATD, its data processing, and its certification systems.

Various radar systems have been proposed as collision avoidance sensors for automatic braking and warning applications. Practical use of laser radar systems is near with the introduction of high power, high reliability laser diodes. Utilizing these new devices, a laser radar system has been adapted for measuring the distance to objects in its path. It was first shown that reflectors on the rear of the automobile possess high reflectivity and sharp directivity. Given these characteristics, a compact laser radar system was tested that employed 12W laser diodes and PIN photodiodes. The maximum range of approximately 100 m was obtained. Furthermore, the ability to discriminate other vehicles from roadside objects was achieved by detecting discontinuity in measured distance data through a microprocessor. These results show that the performance of laser radar is comparable to that of microwave radar.

The Ford CHESS computer program was used to evaluate headlamp performance as a function of various influencing factors such as beam pattern, aim, and overall intensity. The degree to which the model was sensitive to headlamp, driver, and environmental variables was assessed. The results showed that only small increases in performance could be achieved by beam pattern modifications, improved aim, and increased overall intensity. Part of the difficulty in identifying performance improvements was found to be the low sensitivity of the CHESS figure of merit to changes in beam photometrics. Suggestions are made for upgrading the CHESS evaluation methodology to make the performance metrics more sensitive to differences in beam design.

In static and semidynamic tests, the luminances of stop lamps and rear-position lamps were rated by test persons. Out of these results, the influence of light-intensity, area of the light-emitting surface, and observation distance on the assessment of the luminance is shown.

There are currently two accepted criteria for assessment act exposures. Our studies have shown an interaction between the deformation velocity and level of compression during impact, resulting in a greater compression tolerance for low-speed impact than for high-speed loadings. High-speed thoracic impact can cause critical or fatal injury in physiologic experiments before exceeding the acceleration or compression tolerance. The velocity-sensitive tolerance is represented by the maximum product of velocity of deformation and compression, which is derivable from the chest compression response. As the magnitude of this “viscous” response increases, the risk of serious or fatal injury increases. This paper discusses the analysis of available literature and results from our laboratory and demonstrates the need for a viscous tolerance criterion to assess chest impact protection in high-velocity impact.

Nygren(1) showed that whiplash injuries in rear-end collisions often lead to permanent disability. Ten percent of those initially complaining about neck pain after a rear-end collision had remaining problems 5 years after the accident and were judged as permanently, medically disabled. It was also shown that fitted headrests had little effect in preventing whiplash injuries. Fixed headrests reduced the incidence of whiplash injuries by 24 percent, while adjustable headrests reduced the risk by only 14 percent. The results of whiplash injuries in terms of permanent disability were not affected by headrest fitting and type. The present study is based on 339,675 accidents and determines if the variations of the effects of headrests in different car models could be explained by their type and position.

Blunt thoracic impact as experienced by automobile occupants in frontal impact has received considerable research attention over the past 20 years. These efforts have provided the basis for the development of test dummy impact response specifications as well as evaluation criteria to be used in conjunction with the dummy to evaluate the hazard of various crash situations. This paper will attempt to extend the current understanding if thoracic injury production by examining the results of 82 impact tests to determine the effects that several fundamental parameters have on the production of injuries in the thorax.

Two candidate functions for the prediction of pelvic fracture probability are created using lateral pelvic acceleration and age data from 84 cadaver impact experiments. These functions include measures of bone stress, bone strain, age, and load concentration factor. Data are analyzed using the maximum likelihood approach, and it Is found that representation of the data by a Weibull distribution yields higher maximum likelihood than does the assumption of an underlying normal distribution. Additional data are presented documenting pelvic force and acceleration responses for both cadavers and the Side Impact Dummy (SID). Systematic differences are noted and discussed.

EUROSID is the side impact dummy that has been designed and has now been almost completely developed by a group of European research laboratories working together under the auspices of the European Experimental Vehicles Committee (EEVC). It represents a bringing together of components and ideas from the three experimental sided impact dummies sponsored by the EEC1 as part of their Biomechanics Programme. These were produced by APR (Peugeot-Renault), ONSER, and MIRA. This paper describes the evolution of the EUROSID dummy and discusses the advances in biofidelity, the responses of its various components to impact, and the types of measurements it can record.

Most of the thoracic injury criteria proposed these past years are based mainly on the analysis of data obtained from experiments with human cadavers and are related principally to rib fractures. And yet, the actual threat to life incurred in real accidents results from lesions to intrathoracic viscerae that are not necessarily correlated with the number of rib fractures. Moreover, the injuries sustained by cadavers during experiments are mainly rib fractures. In these cases, visceral lesions are unusual and not necessarily identical with those sustained by real accident victims. Preliminary results of measurements concerning rib strength and dynamic behavior of the cadaver thorax in frontal impacts show the rib cage offers a low resistance against compression and the vertebral column acts as a stop. The combination of these various data leads to questioning the validity of thoracic injury criteria based on the number of rib fractures observed on human cadavers.

This paper describes a test programme in which examples of six models of popular 1983 lower-medium-size four-door cars were subjected to front, side, and interior headform impacts to assess occupant protection. The frontal test was a 30° angled impact into a wood-faced barrier at 60km/ h using restrained OPAT dummies. The side test was a 90° impact from a CCMC deformable mobile barrier at 50km/h. using a prototype Eurosid dummy to represent the driver. The interior headform tests used a 6.8kg free-flight headform launched from an air gun at 24km/h to impact 21 points that occupants are likely to strike in an accident. The results of these tests are summarised and used to compare the occupant protection offered by the different car models and also to see whether the average level has changed since a previous set of similar TRRL tests on 1976 cars.

As part of the development of a simulation model for side impact accidents, it has been necessary to develop a model of the human thorax. This is required to provide both the correct dynamic interface with the simulation of the car structure and a reasonable criterion of injury probability. In terms of designing structures (such as additional padding) that will maximise occupant protection, it is important to have a good understanding of the dependence of injury on the time history of the impact forces. It is only possible to develop a complete model of a system as complex as the thorax in terms of a step-by-step simulation. However, an analytical model has also been developed to describe the third order mass/spring/damper system that forms a major subsystem in the step-by-step simulation. This differs from the ordinary second order mass/spring/damper system by having an additional spring in series with the damper, which gives a softer response to a sudden impact.

Although recent developments in tire puncture-proofing media have overcome prior problems associated with durability, all such materials prejudice vehicle ride to some degree when compared with air inflation. This is particularly undesirable in many off-road applications where flat-proofing of low-pressure tires is a necessity. This paper describes the development and performance characteristics of a new 5-Durometer elastomeric polymer system with significantly improved ride, as well as recent work investigating the protective mechanism of a so-called “champagne-bubble effect” in limiting heat build-up in recently-developed water-cured urethane tire fill systems.