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A detailed description of the oxidative stability of GM's DEXRON®-VI Factory Fill Automatic Transmission Fluid (ATF) is provided, which can be integrated into a working algorithm to estimate the end of useful oxidative life of the fluid. As described previously, an algorithm to determine the end of useful life of an automatic transmission fluid exists and is composed of two simultaneous counters, one monitoring bulk oxidation and the other monitoring friction degradation [1]. When either the bulk oxidation model or the friction model reach the specified limit, a signal can be triggered to alert the driver that an ATF change is required. The data presented in this report can be used to develop the bulk oxidation model. The bulk oxidation model is built from a large series of bench oxidation tests. These data can also be used independent of a vehicle to show the relative oxidation resistance of this fluid, at various temperatures, compared to other common lubricants.

A driving simulator development project at the Systems Engineering and Technical Process Center (SE/TP) is exploring the role of driving simulation in the vehicle design process. The simulator provides two vehicle mockup testing arenas that support a wide field of view, computer-generated image of the road scene which dynamically responds to driver commands as a function of programmable vehicle model parameters. Two unique aspects of the simulator are the fast 65 ms response time and low incidence rate of simulator induced syndrome (about 5%). Preliminary model validation results and data comparing driver performance in a vehicle vs. the simulator indicate accurate handling response dynamics within the on-center handling region (<0.3g lateral acceleration). Applications have included supporting the development of new steering system concepts, as well as evaluating the usability of vehicle controls and displays.

The dilemma of using a shoulder belt force limiter with a 3-point belt system is selecting a limit load that will balance the reduced risk of significant thoracic injury due to the shoulder belt loading of the chest against the increased risk of significant head injury due to the greater upper torso motion allowed by the shoulder belt load limiter. However, with the use of air bags, this dilemma is more manageable since it only occurs for non-deploy accidents where the risk of significant head injury is low even for the unbelted occupant. A study was done using a validated occupant dynamics model of the Hybrid III dummy to investigate the effects that a prescribed set of shoulder belt force limits had on head and thoracic responses for 48 and 56 km/h barrier simulations with driver air bag deployment and for threshold crash severity simulations with no air bag deployment.

As the driving population ages, there is a need to understand the accident patterns of older drivers. Previous research has shown that side impact collisions, usually at an intersection, are a serious problem for the older driver in terms of injury outcome. This study compares the frequency of side impact, intersection collisions of different driver age groups using state and national police-reported accident data as well as an in-depth analysis of cases from a fatal accident study. All data reveal that the frequency of intersection crashes increases with driver age. The state and national data show that older drivers have an increase frequency of intersection crashes involving vehicles crossing paths prior to the collision compared to their involvement in all crash types. When taking into account traffic control devices at an intersection, older drivers have the greatest involvement of multiple vehicle crashes at a signed intersection.

A study was conducted by General Motors at its crash test facility located at the Milford Proving Ground. The intent of this study was to expand upon the currently available research regarding the safety belt buckle environment during full scale planar crash tests. Buckle accelerations and webbing tensions were measured and recorded to characterize, in part, buckle responses in a crash environment. Previous studies have focused primarily on the component level testing of safety belt buckles. The crash tests included a variety of vehicles, impact types, seating positions, Anthropomorphic Test Devices (ATDs), impact speeds, and impact angles. Also included were various safety belt restraint systems and pretensioner designs. This study reports on data recorded from 100 full scale crash tests with 180 instrumented end release safety belt buckles. Acceleration measurements were obtained with tri-axial accelerometers mounted onto the buckles.

This paper presents an extensive research program undertaken to develop improved side impact test methods. The development of a component side impact test device along with an associated test procedure are reviewed. The results of accident data analysis techniques to define anatomical areas most likely to be injured during side impact and definition of test device response corridors based on human surrogate testing conducted by the Association Peugeot/Renault and the University of Heidelberg are discussed. The relationship of response corridors and accident data analysis in earlier phases of the project resulted in definition and development of a component side impact test device to represent the human thorax. A test program to evaluate and compare component and full-vehicle test results is presented.

This paper presents the results of a series of over 30 impact sled simulations of racing car frontal crashes conducted as part of the GM Motorsports Safety Technology Research Program. A Hyge™ impact sled fitted with a simulated racing car seat and restraint system was used to simulate realistic crash loading with a mid-size male Hybrid III dummy. The results of tests, in the form of measured loads, displacements, and accelerations, are presented and comparisons made with respect to the levels of these parameters seen in typical passenger car crash testing and to current injury threshold values.

This paper describes a numerical simulation technique applicable to the FMVSS 214 side impact test through the use of the finite element method (FEM) technology. The paper outlines the development of the side impact dummy (SID), moving deformable barrier (MDB) and the test vehicle FEM models, as well as the development of new advanced constitutive models of materials and algorithms in LS-DYNA3D which are related to the topic. Presented in the paper are some initial simulation problems which were encountered and solved, as well as the correlation of the simulation data to the physical test.

Side impact dummy (SID) is a human-like test device used in the National Highway Transportation Safety Administration (NHTSA) mandated side impact test of vehicles sold in the USA. A finite element model of SID has been developed at GM as a part of a project to simulate the side impact test. The objective is to better predict physical test results by replacing traditional rigid-body lumped parameter models with a finite element model. The project included, besides mesh generation, the development of new LS-DYNA3D constitutive models for rubber and foam-like materials, and enhancements of contact interface and other algorithms. This paper describes the GM SID finite element model and its performance in side impact test simulations.

A relationship between the risk of significant thoracic injury (AIS ≥ 3) and Hybrid III dummy sternal deflection for shoulder belt loading is developed. This relationship is based on an analysis of the Association Peugeot-Renault accident data of 386 occupants who were restrained by three-point belt systems that used a shoulder belt with a force-limiting element. For 342 of these occupants, the magnitude of the shoulder belt force could be estimated with various degrees of certainty from the amount of force-limiting band ripping. Hyge sled tests were conducted with a Hybrid III dummy to reproduce the various degrees of band tearing. The resulting Hybrid III sternal deflections were correlated to the frequencies of AIS ≥ 3 thoracic injury observed for similar band tearing in the field accident data. This analysis indicates that for shoulder belt loading a Hybrid III sternal deflection of 50 mm corresponds to a 40 to 50% risk of an AIS ≥ 3 thoracic injury.

Fatal crash circumstances for 48 belted female drivers were studied in-depth and compared to those of 83 belted male drivers in a similar population of vehicles. Women had a higher incidence of crashes on slippery roads, during lane changes and passing maneuvers than men who had a higher rate of aggressive driving and speed related crashes (χ2 = 10.47, p < 0.001). Driver-side damage was significantly more frequent in female than male crashes (χ2 = 5.74, p < 0.025) and women had a higher fraction of side impacts (45.9% v 31.4%) and crashes during daylight (87.0% v 72.3%, χ2 = 3.65, p < 0.05) than men. Women also had a higher fraction of potentially avoidable crashes than men (57.5% v 39.0%) and a lower involvement related to aggressive driving (10.6% v 25.6%). These differences were statistically significant (χ2 = 5.41, p < 0.025).

Truck driver shin-knee and stomach postion tools have been developed to describe where certain percentages of truck drivers position there knees and stomachs in various workspace arrangements. Separate equations describe the accommodation level for driver populations with male to female ratios of 50/50, 75/25, and a range from 90/10 to 95/5. These equations can be used as a design tool to locate the curves in vehicle space to describe the region behind which the given populations shin-knees, and stomachs would be located. Equations and curves are provided for both the left leg, which operates the clutch, and the right leg, which operates the accelerator.

Truck driver eye and head position tools have been developed to describe where certain percentages of truck drivers position there eyes and heads in various workspace arrangements. Separate equations describe the accommodation level for driver populations with male to female ratios of 50/50, 75/25, and a range from 90/10 to 95/5. These equations can be used as a design tool to locate the curves in vehicle space to describe the region behind which the given populations eyes and heads would be located. Equations and curves are provided for both the drivers eye and head in the side view. It has become increasingly apparent that there is a need for improved methods of accommodating truck drivers in heavy truck cab design. Currently, practices used in the automobile industry for passenger car design are utilized for the design of heavy trucks. These practices.

Many traffic collisions are the result of the driver's failure to notice the other vehicle. It is often cited in police reports that the driver "looked but did not see.'' The purpose of Daytime Running Lights (DRLs) is to increase the visual contrast of DRL-equipped vehicles. Visual contrast, which is the difference in brightness between two areas, is an important characteristic enabling a driver to detect objects. This paper begins with a brief regulatory history of DRLs in the U.S. and how General Motors Corporation (GM) introduced DRL-equipped vehicles. It also describes a DRL effectiveness study conducted by Exponent Failure Analysis Associates of San Francisco for General Motors Corporation. The study compared the collision rates of specific General Motors Corporation, Saab, Volvo and Volkswagen vehicles before and immediately after the introduction of DRLs. Since DRLs are not visible from behind a vehicle, rear-end collisions were not included in the study.

The causes for 131 fatal crashes of lap-shoulder belted occupants were analyzed for crash causation and avoidance opportunities. Fourteen crash scenarios were determined to depict the situation and circumstance of the accidents. Each scenario is discussed in relation to driver age, actions, behavior, errors and aggressiveness, as well as crash type and other factors influencing the crash. Nearly a third of crashes involved a rapid, unpredictable onset by reckless action or mistake of another driver. The remainder were caused by the driver of the case-vehicle. Some were single vehicle crashes primarily related to excessive speed, aggressive driving, and drifting out of lane. The others were multi-vehicle crashes due primarily to inadvertent errors. The most common errors were right-of-way violations at an intersection, loss of control on wet roads, impact of a stationary vehicle, and lane changing errors.

The purpose of the Cadillac DeVille Night Vision System is to provide drivers with visual information beyond with the range of their headlamps. It can also help drivers see beyond the glare of oncoming vehicle’s headlamps. With increased visual range the driver may have more time to react to potentially dangerous situations. The system consists of a thermal imaging camera, a head-up display, and image controls. The camera senses temperature differences of objects in the road scene ahead and creates a thermal image of the scene. The head-up display projects this image onto the windshield creating a virtual image that appears at the front edge of the vehicle’s hood just below the driver’s line of sight. This paper will describe the system requirements and parameters of the 2000 Cadillac DeVille Night Vision system.

An objective, biomechanically based assessment is made of the risks of life-threatening brain injury of frontal crash test results. Published 15 ms HIC values for driver and right front passenger dummies of frontal barrier crash tests conducted by Transport Canada and NHTSA are analyzed using the brain injury risk curve of Prasad and Mertz. Ninety-four percent of the occupants involved in the 30 mph, frontal barrier compliance tests had risks of life-threatening brain injury less than 5 percent. Only 3 percent had risks greater than 16 percent which corresponds to 15 ms HIC > 1000. For belt restrained occupants without head contact with the interior, the risks of life-threatening brain injury were less than 2 percent. In contrast, for the more severe NCAP test condition, 27 percent of the drivers and 21 percent of the passengers had life-threatening brain injury risks greater than 16 percent.

This study assembled a database of anatomic dimensions of Indy Car drivers and developed procedures that can be used as models for future compilations of anatomic data from specialized populations. The database defines the body configuration for the Indy Car driver population and indicates that the current HYBRID III, midsize male crash dummy will provide a reasonable approximation of that population if used in investigations involving issues of crash protection. This study took advantage of a unique opportunity to assemble an anthropometric database from a specialized population which was compared to an existing database collected from a comparable sub-set of the United States population.

This study examined whether the effect of subsidiary tasks on driving performance can be predicted from stationary (static) testing. Alternative methods for assessing the performance of drivers during their use of in-vehicle information systems were examined. These methods included static testing in stationary vehicles, as well as dynamic, on-road testing. The measures that were obtained from static tests were evaluated in terms of how well they could predict measures obtained from driving performance during on-road testing (which included concurrent use of secondary information systems). The results indicated that measures obtained in static test settings were highly correlated with corresponding measures obtained from on-road performance testing.