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The severity of an impact in terms of the acceleration in the occupant compartment is dependent not only on the change in vehicle velocity, but also the time for the change in velocity to occur. These depend on the geometry and stiffness of both the striking vehicle and struck object. In narrow-object frontal impacts, impact location can affect the shape and duration of the acceleration pulse that reaches the occupant compartment. In this paper, the frontal impact response of a full-sized pickup to 10 mile per hour and 20 mile per hour pole impacts at the centerline and at a location nearer the frame rails is compared using the acceleration pulse shape, the average acceleration in the occupant compartment, and the residual crush. A bilinear curve relating impact speed to residual crush is developed.

This paper describes an adaptive control strategy for improving the steering response of an automated vehicle steering controller. In order to achieve repeatable dynamic test results, precise steering inputs are necessary. This strategy provides the controller tuning parameters optimized for a particular vehicle's steering system. Having the capability to adaptively tune the steering controller for any vehicle installation provides an easy method for obtaining precise steering inputs for a wide range of vehicles, from small off-road utility vehicles to passenger vehicles to heavy trucks. The S.E.A. Ltd. Automated Steering Controller (ASC) is used exclusively in conducting this research. By recording the torque input to the steering system by the steering controller and the resulting steering angle during only a single test, the ASC is able to characterize the steering system of the test vehicle and create a computer model with appropriate parameters.

This paper describes the design and development of the hardware, electronics, and software components of a state-of-the-art automated steering controller, the SEA, Ltd. ASC. The function of the ASC is to input to a vehicle virtually any steering profile with both high accuracy and repeatability. The ASC is designed to input profiles having steering rates and timing that are in excess of the limits of a human driver. The ASC software allows the user to specify steering profiles and select controller settings, including motor controller gains, through user-interface windows. This makes it possible for the test driver to change steering profiles and settings immediately after running any test maneuver. The motor controller used in the ASC offers self-contained signal input, output, and data storage capabilities. Thus, the ASC can operate as a standalone steering machine or it can be incorporated into typical existing, on-vehicle data acquisition systems.

This paper discusses the improvement of a heavy truck anti-lock brake system (ABS) model currently used by the National Highway Traffic Safety Administration (NHTSA) in conjunction with multibody vehicle dynamics software. Accurate modeling of this complex system is paramount in predicting real-world dynamics, and significant improvements in model accuracy are now possible due to recent access to ABS system data during on-track experimental testing. This paper focuses on improving an existing ABS model to accurately simulate braking under limit braking maneuvers on high and low-coefficient surfaces. To accomplish this, an ABS controller model with slip ratio and wheel acceleration thresholds was developed to handle these scenarios. The model was verified through testing of a Class VIII 6×4 straight truck. The Simulink brake system and ABS model both run simultaneously with TruckSim, with the initialization and results being acquired through Matlab.

This paper presents the results of actual in service testing of a diesel fuel supplement, specifically a 20-80% blend of waste vegetable oil and diesel No. 1. Tests are presented illustrating the effects of smoke readings, viscosity, specific gravity, and mileage with the 20-80 blend. Coupled with these results was the actual diesel engine tear down. The bus engine inspection included the head, piston heads, injectors, rings, and intake ports. The results of this in service test indicate that a diesel engine without any modification will run successfully on a blend of 20% waste vegetable oil and 80% diesel fuel without damage to the engine parts. Additionally only a diesel No. 1 blend was found to be satisfactory in cold weather unless measures are taken to prevent filter plugging. Finally, the results of this study indicate that the use of waste soybean oil as a diesel fuel extender is a viable short term energy solution based on economics as well as engine performance.

The development of injury predictive models for pedestrian thoracic impact based on experimental data obtained in a previous study is presented. The data consists of ten cadaveric test subjects including eight side and two frontal impacts. A ten accelerometer array was mounted on the thorax to define thoracic kinematics. Three types of parameters, Q, B, and PSD, are developed to summarize each acceleration signal. A statistical regression is performed to generate empirical models for predicting the injury level (number of rib fractures) from these parameters. Coefficients of determination for these models range from 0.8 to 0.99 with the new PSD parameter showing exciting promise. Success of these parameters in predicting thoracic injury implies a relationship with frequency, particularly in the neighborhood of 60 Hz.

Pedestrian injuries are examined using the PICS data file for effects of pedestrian age, vehicle speed, and source of the injury. It is shown that the more severe injuries are caused by contact with the vehicle, and that a stiff structure becomes increasingly more dangerous, not only as speed increases, but as the pedestrian's age increases.

A study is being conducted in which both component level and full scale crash tests are being compared. This report documents the approach selected for component level testing and the matrix selected for full scale crash testing. The hardware that was fabricated to conduct the component tests is shown and discussed. The component test results to date are discussed as to repeatability, durability and ability to discriminate between levels of safety.

Three groups of crash tests were analyzed to determine how well the standard fixed rigid barrier measures potential crash survivability in small cars when impacted full frontally by larger cars. In addition to experimental results, simple analytical methods were used to determine and compare the level of occupant protection in the small cars. The fixed rigid barrier appears to be an accurate crashworthiness-measuring device for small cars in high speed full frontal car/car collisions, if test velocities are selected on the basis of equivalent energy between car/barrier and car/car collisions as opposed to equivalent momentum.

Two computer models, ABAG 19 and HSRI-3D, were validated against experimental data to determine and compare their capability for simulating the responses of air bag restrained automobile occupants in severe frontal collisions. Standard sets of model input parameters were developed for both driver and passenger. The primary objective was to determine which model was best suited for determining potential crashworthiness in a large number of production vehicles. Advantages and disadvantages of the models were determined, using criteria such as accuracy, ease of use, quality of documentation and user orientation.

Accident reconstruction encompasses the evaluation of a crash situation from evidence and observations available after the accident. Such evidence includes vehicular damage, property damage, marks, and witness statements. The reconstructionist is responsible for transforming this information into a theory of the accident sequence. In addition to satisfying the evidence and statements, the theory must also agree with the laws of physics which dictate reactions to forces and torques. The computer program presented here assists in this analysis by providing a graphical depiction of the accident scenario. This program is called ANMATE and utilizes simulation results prepared by the CRASH or SMAC program for vehicle motions. A number of features assist in viewing the accident from different points of view, allow the user to stop action, and provide other data presentation formats. A real world example is given.

The roof structures of light utility vehicles are often comprised of a single composite shell without the usual steel or aluminum frames found on conventional passenger automobiles. This study analyzes the geometry of such structures in relation to their performance during rollover accident and roof intrusion. For a given set of material properties and roof impact velocity, their exists an optimum value of roof stiffness that would minimize the impact energy, manifested in a rollover accident, that would be transmitted to the occupant compartment. This work shows the effects of various geometric parameters on the amount of elastic strain energy that can be absorbed during deformation of the rooftop. The optimum roof geometry was determined to minimize the possibility of, if not the severity of, occupant injury.

This paper describes the development of a device to simulate the thorax of the fiftieth percentile six year old child in lateral blunt impact. The device is to be used to reconstruct actual vehicle/pedestrian collisions to determine the injury potential that various vehicles have towards pedestrians. The device is a modification of a fiftieth percentile six year old dummy thorax. Verification of the response is made by comparison with adult cadaver lateral impact data normalized and scaled to the child case. Performance evaluation of the device gave encouraging results although repeatability needs further verification.

This paper presents a pedestrian head impact reconstruction methodology as an initial mitigating response to this need for pedestrian protection. This methodology which is based on preliminary testing results is illustrated with a real world case example from the Pedestrian Accident Investigation Data Support (PAIDS) Study. This PAIDS study provides documentation of medical reports, vehicle impact speeds, photographs and a dent profile of the vehicle damage. The pedestrian head impact damage from this real-world case is reproduced in a comparison vehicle with a rigid pneumatic impactor developed for the National Highway Traffic Safety Administration. The physical reconstruction results are then compared to the actual accident damage and conclusions are rendered.

The objective of this paper is to develop a self-tuning optimal control of an active suspension. An active suspension composed of an identifier and a controller is proposed in this paper. Although control strategies on active (or semi-active) suspensions have been investigated during the past few decades, some problems are not well understood yet. One of them arising from the ride control of an active suspension is that when the weight and the moments of inertia of the sprung mass are varied, the feedback gains of the controller should vary with the variation of parameters accordingly. Therefore, the identifier is proposed before the controller is designed. In the real situations, the parameter variation may occur when loadings on vehicles vary - either from passengers or payloads, especially, in the case of loading on a truck. An identification structure using parallel model reference adaptive system (MRAS) is proposed to identify the true parameters.

Pedestrian vehicle accidents account for a considerable proportion of all automobile related injuries and deaths each year. Due to the large difference in mass between the pedestrian and the vehicle, pedestrian injury reduction is a formidable task. In spite of these difficulties, world attention is beginning to focus on pedestrian injuries and methods to quantitatively evaluate a vehicle for its pedestrian injury potential. This paper reviews the status of work in the United States on devices and methods for measuring pedestrian impact response. Where data is available test device response is summarized. The state of pedestrian accident research is also reviewed in the light of national and International interest in reducing pedestrian injuries.

Seat belt usage in the United States is increasing dramatically, due in part to legislative action. In addition, education programs have improved public awareness of the need for automotive restraints in achieving crash survival and injury reduction. The safety consciousness level of automobile passengers is particularly strong among pregnant women. It is reasonable to expect wider use of seat belts by expectant mothers due to this acute attention to safety. The literature demonstrates that incorrect usage of seat belts is a cause of injury. This can be especially applicable during pregnancy when changes in anatomy dictate a change in belt positioning, Review of the literature shows that the technical issues associated with the use of current production belt restraint systems by pregnant women has not been addressed.

The change in velocity (Delta V) has; been used widely to evaluate the severity of vehicle damage and injuries suffered by vehicle occupants during a car crash. A high Delta V usually means severe car damage together with serious occupant injuries. In contrast, a low Delta V would mean little damage and less injuries. Many car accidents typically involve significant change in vehicle rotational velocity during the crash. Subsequently, vehicle damage and occupant injuries do not appear to correlate to the Delta V of the vehicle in the normal fashion. This paper examines the effects of the change in angular velocity (Delta w) on the localized or effective Delta V experienced by an occupant in a crash environment.

Vehicular accidents occur in everyday life. Their degree of severity is often perceived by the general public based on the amount of human bodily injuries sustained. Nevertheless, accident reconstructionists measure the degree of severity of vehicular accidents by calculating terms that are called Collision Parameters. The principal objective of this paper is to describe the significance of the Collision Parameters and explain the vocabulary of accident reconstruction. A non-mathematical approach is utilized to provide a thorough understanding for the general public.