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The paper discusses the development of a model for the 2006 BMW 330i for the National Advanced Driving Simulator's (NADS) vehicle dynamics simulation, NADSdyna. The front and rear suspensions are independent strut and link type suspensions modeled using recursive rigid-body dynamics formulations. The suspension springs and shock absorbers are modeled as force elements. The paper includes parameters for front and rear semi-empirical tire models used with NADSdyna. Longitudinal and lateral tire force plots are also included. The NADSdyna model provides state-of-the-art high-fidelity handling dynamics for real-time hardware-in-the-loop simulation. The realism of a particular model depends heavily on how the parameters are obtained from the actual physical system. Complex models do not guarantee high fidelity if the parameters used were not properly measured. Methodologies for determining the parameters are detailed in this paper.

This paper presents the details of the model for the physical steering system used on the National Advanced Driving Simulator. The system is basically a hardware-in-the-loop (steering feedback motor and controls) steering system coupled with the core vehicle dynamics of the simulator. The system's torque control uses cascaded position and velocity feedback and is controlled to provide steering feedback with variable stiffness and dynamic properties. The reference model, which calculates the desired value of the torque, is made of power steering torque, damping function torque, torque from tires, locking limit torque, and driver input torque. The model also provides a unique steering dead-band function that is important for on-center feel. A Simulink model of the hardware/software is presented and analysis of the simulator steering system is provided.

The paper discusses the development of a model for a 1998 Chevrolet Malibu for the National Advanced Driving Simulator’s (NADS) vehicle dynamics simulation, NADSdyna. The Malibu is the third vehicle modeled for the NADS, and this is the third paper dealing with model development. SAE Paper 970564 contains details of the model for the 1994 Ford Taurus and SAE Paper 1999–01-0121 contains details of the model for the 1997 Jeep Cherokee. The front and rear suspensions are independent strut and link type suspensions modeled using recursive rigid body dynamics formulations. The suspension springs and shock absorbers are modeled as elements in the rigid body formulation. To complement the vehicle dynamics for the NADS application, subsystem models that include tire forces, braking, powertrain, aerodynamics, and steering are added to the rigid body dynamics model. The models provide state-of-the-art high fidelity vehicle handling dynamics for real-time simulation.

This paper describes ongoing research conducted by the National Highway Traffic Safety Administration (NHTSA) to evaluate the potential of safety restraints on large school buses. School bus transportation is one of the safest forms of transportation in the United States. Large school buses provide protection because of their visibility, size, and weight, as compared to other types of motor vehicles. Additionally, they are required to meet minimum Federal Motor Vehicle Safety Standards (FMVSS) mandating compartmentalized seating, emergency exits, roof crush and fuel system integrity, and minimum bus body joint strength.

This paper provides an overview of a cooperative research program between General Motors Corporation and the National Highway Traffic Safety Administration to conduct a field operational test of a rear-end collision warning system. A description of the system architecture is also presented.

NHTSA uses a variety of computer modelling techniques to develop and evaluate test methods and mitigation concepts, and to estimate safety benefits for many of NHTSA's research activities. Computer modeling has been particularly beneficial for estimating safety benefits where often very little data are available. Also modeling allows researchers to augment test data by simulating crashes over a wider range of conditions than would otherwise be feasible. These capabilities are used for a wide range of projects from school bus to frontal, side, and rollover research programs. This paper provides an overview of these activities. NHTSA's most extensive modeling research involves developing finite element and articulated mass models to evaluate a range of vehicles and crash environments. These models are being used to develop a fleet wide systems model for evaluating compatibility issues.

This paper presents an overview of NHTSA's vehicle aggressivity and fleet compatibility research activities. This research program is being conducted in close cooperation with the International Harmonized Research Agenda (IHRA) compatibility research group. NHTSA is monitoring the changing vehicle mix in the U.S. fleet, analyzing crash statistics, and evaluating any implications that these changes may have for U.S. occupant safety. NHTSA is also continuing full-scale crash testing to develop a better understanding of vehicle compatibility and to investigate test methods to assess vehicle compatibility.

This paper focuses on the overall structure of the Crash Injury Research and Engineering Network (CIREN), how data are collected, and what makes it unique. It discusses how it can be used to expand and enhance the information in other databases. CIREN is a collaborative effort to conduct research on crashes and injuries at nine Level 1 Trauma Centers which are linked by a computer network. Researchers can review data and share expertise, which will lead to a better understanding of crash injury mechanisms and the design of safer vehicles. CIREN data are being used in outreach and education programs on motor vehicle safety. CIREN outreach and education has already been credited with lifesaving information dissemination.

This paper describes computer crash simulations performed by the National Highway Traffic Safety Administration (NHTSA) under the current research and testing activities on large school bus safety restraints. The simulations of a frontal rigid barrier test and comparative dynamic sled testing for compartmentalization, lap belt, and lap/shoulder belt restraint strategies are presented. School bus transportation is one of the safest forms of transportation in the United States. School age children transported in school buses are safer than children transported in motor vehicles of any other type. Large school buses provide protection because of their size and weight. Further, they must meet minimum Federal motor vehicle safety standards (FMVSSs) mandating compartmentalized seating, improved emergency exits, stronger roof structures and fuel systems, and better bus body joint strength.

A review was conducted of injuries associated with ejection through motor vehicle glazing, using the 1988 through 1991 National Accident Sampling System data maintained by the National Highway Traffic Safety Administration. The review indicated that one percent of the occupants in towaway crashes were ejected and that 22 percent of fatalities in towaway crashes were ejected. Fifty-three percent of complete ejections were through the glazing openings in motor vehicles. Current motor vehicle glazing does not contribute significantly to occupant injuries, but the effects of glazing changes on serious injuries will need to be considered.

This report is a condensed version of the December 1993 New Car Assessment Program (NCAP) report to Congress and provides: an historical review and future goals for NCAP. the results of an 18-month study to assess consumer and media needs in understanding and promoting the use of NCAP data. This included consumer focus groups and media studies. These studies indicated that consumers and the media desire comparative safety information on vehicles, a simplified NCAP format to better understand and utilize the crash test results, and would like to see NCAP expanded to include other crash modes. studies of real-world crashes versus NCAP crash tests. These studies conclude that NCAP test conditions approximate real-world crash conditions covering a major segment of the frontal crash safety problem and that there is a significant correlation between NCAP results and real-world fatality risks for restrained drivers.

In the New Car Assessment Program (NCAP), beginning with the model year 1994 vehicles, the National Highway Traffic Safety Administration (NHTSA) developed and adopted a simplified nonnumeric format for presenting the comparative frontal crashworthiness safety information to consumers. This paper presents the basis for the development of this “star rating” system. The injury probability functions which are used for the star rating system are also applied to the results of the recent NCAP real-world correlation studies and a review of these studies is given. The safety performance for restrained occupants as measured in NCAP is dependent on several parameters which include: the design of the restraint system, the maintenance of the integrity of the occupant space, and the energy management performance of the front structure.

This paper presents an overview of work performed by the National Highway Traffic Safety Administration's (NHTSA) Vehicle Research and Test Center (VRTC) to test, validate, and improve the planned National Advanced Driving Simulator's (NADS) vehicle dynamics simulation. This vehicle dynamics simulation, called NADSdyna, was developed by the University of Iowa's Center for Computer-Aided Design (CCAD) NADSdyna is based upon CCAD's general purpose, real-time, multi-body dynamics software, referred to as the Real-Time Recursive Dynamics (RTRD), supplemented by vehicle dynamics specific submodules VRTC has “beta tested” NADSdyna, making certain that the software both works as computer code and that it correctly models vehicle dynamics. This paper gives an overview of VRTC's beta test work with NADSdyna. The paper explains the methodology used by VRTC to validate NADSdyna.

This paper presents an approach for evaluating the effects of brake system component degradation on vehicle braking performance. The approach involves the use of an inertial brake dynamometer, vehicle computer simulation, and vehicle test. The approach, procedures, and results of the study of the effects of worn friction materials, worn discs and drums, and contaminated brakes are presented.

This paper addresses the protection of occupants in light vehicles. It presents data and techniques for identifying and measuring potential crashworthiness improvements that would mitigate injuries to occupants striking frontal interior components such as the steering wheel, instrument panel and windshield. Both restrained and unrestrained occupants can be injured by frontal interior components in crashes. The focus of this paper is on the unrestrained occupant. However, performance criteria and associated countermeasures will have to be developed considering the differences in the mechanisms of injury to both the restrained and unrestrained occupants. Work on the restrained occupant and the similarities and differences between both conditions remains to be considered. The paper presents information on the magnitude and types of injuries received from frontal interior components and on how the performance of these components and the vehicle structure affect the resultant injuries.

This paper presents the methodology and results of an analysis of the available information on motor vehicle safety which could be used to provide a basis for establishing priorities for future Government and private sector efforts directed at enhanced crash protection. The work was stimulated by several factors: (1) 5 years have elapsed since the National Highway Traffic Safety Administration (NHTSA) published a plan for motor vehicle safety research and development, (2) motor vehicles have changed substantially over the past several years, (3) the quantity and quality of accident data and vehicle crash performance information have increased dramatically over the past 5 years, and (4) Government policies and the amount of Government and private sector resources available for future efforts are changing.

The absence of data on the load deflection and energy absorption characteristics of vehicle interiors has been a factor which limits the accuracy of crash victim simulations. A recent test program conducted for the National Highway Traffic Safety Administration has developed data on the interactions of dashboards and knee panels with chests and knees. This paper summarizes the test results for several vehicles and shows how these results are used in simulating vehicle crash tests. Comparisons between crash tests and computer reconstruction using the 3-Dimensional Crash Victim Simulator (CVS-3D) for a late model car are included. The simulation shows good agreement with test and illustrates the application of available static and dynamic test data to improve occupant simulations.

The injury reducing effectiveness of child safety seats in frontal crashes was evaluated, based on 36 frontal or oblique sled tests run with two or more GM three-year-old dummies in the simulated passenger compartment of a car. Unrestrained, correctly restrained and incorrectly restrained dummies were tested at the range of speeds where most nonminor injuries occur (15-35 mph). Accident data from NHTSA files were used to calibrate a relationship between the front-seat unrestrained dummies' HIC and unrestrained children's risk of serious head injuries; also between torso g's and the risk of serious torso injuries. These relationships were used to predict injury risk for the restrained children as a function of crash speed and to compare it to the risk for unrestrained children. The sled test analysis predicted that the 1984 mix of correctly and incorrectly used safety seats reduced serious injury risk by 40 percent relative to the unrestrained child, in frontal crashes.

The facial laceration test has been proposed as an addition to the dummy injury criteria of Federal Motor Vehicle Safety Standard 208. To better understand laceration conditions as they actually occur, three road crashes of increasing severity, all involving facial laceration by the broken (cracked) windshield and one involving partial ejection, have been simulated physically and analytically. The physical simulations used vehicle test bucks, the Hybrid III head with the chamois facial coverings of the facial laceration test, and a piston - constrained Head Impactor. Computer simulations of the three crashes were also carried out using the CALSPAN 3D “CVS” and the 2D “DRISIM” computer programs. The computer simulations provide insight into the effective mass of the head and body on windshield contact, and the forces, velocities, and accelerations involved.

A major focus of the National Highway Traffic Safety Administration's (NHTSA) vehicle compatibility and aggressivity research program is the development of a laboratory test procedure to evaluate compatibility. This paper is written to explain the associated goals, issues, and design considerations and to review the preliminary results from this ongoing research program. One of NHTSA's activities supporting the development of a test procedure involves investigating the use of an mobile deformable barrier (MDB) into vehicle test to evaluate both the self-protection (crashworthiness) and the partner-protection (compatibility) of the subject vehicle. For this development, the MDB is intended to represent the median or expected crash partner. This representiveness includes such vehicle characteristics as weight, size, and frontal stiffness. This paper presents distributions of vehicle measurements based on 1996 fleet registration data.