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A finite element model of a folded airbag with the module cover and steering wheel system was developed to estimate the injury numbers of a 5th percentile female dummy in an out-of-position (OOP) situation. The airbag model was correlated with static airbag deployments and standard force plate tests. The 5th percentile finite element dummy model developed by First Technology Safety Systems (FTSS) was used in the simulation. The following two OOP tests were simulated with the airbag model including a validated steering wheel finite element model: 1. Chest on air bag module for maximum chest interaction from pressure loading (MS6-D) and 2. Neck on air bag module for maximum neck interaction from membrane loading (MS8-D). These two simulations were then compared to the test results. Satisfactory correlation was found in both the cases.

Hazard analysis plays an important role in the development of safety-critical systems. Hazard analysis techniques have been used in the development of conventional automotive systems. However, as future automotive systems become more sophisticated in functionality, design, and applied technology, the need for a more comprehensive hazard analysis approach has arisen. In this paper, we describe a comprehensive hazard analysis approach for system safety programs. This comprehensive approach involves applying a number of hazard analysis techniques and then integrating their results. This comprehensive approach attempts to overcome the narrower scope of individual techniques while obtaining the benefits of all of them.

It has been reported that lower extremity injuries represent a measurable portion of all moderate-to-severe automobile crash- related injuries. Thus, a simple tool to assist with the design of leg and foot injury countermeasures is desirable. The objective of this study is to develop a mathematical model which can predict load propagation and kinematics of the foot and leg in frontal automotive impacts. A multi-body model developed at the University of Virginia and validated for blunt impact to the whole foot has been used as basis for the current work. This model includes representations of the tibia, fibula, talus, hindfoot, midfoot and forefoot bones. Additionally, the model provides a means for tensioning the Achilles tendon. In the current study, the simulations conducted correspond to tests performed by the Transport Research Laboratory and the University of Nottingham on knee-amputated cadaver specimens.

Steer-by-wire and other “by-wire” systems (as defined in the paper) offer many passive and active safety advantages. To help ensure these advantages are achieved, a comprehensive system-safety process should be followed. In this paper, we review standard elements of system safety processes that are widely applied in several industries and describe the main elements of our proposed analysis process for by-wire systems. The process steps include: (i) creating a program plan to act as a blueprint for the process, (ii) performing a variety of hazard analysis and risk assessment tasks as specified in the program plan, (iii) designing and verifying a set of hazard controls that help mitigate risk, and (iv) summarizing the findings. Vehicle manufacturers and suppliers need to work together to create and follow such a process. A distinguishing feature of the process is the explicit linking of hazard controls to the hazards they cover, permitting coverage-based risk assessment.

The structure of the racecar has been the subject of much discussion with regard to crash safety. The stiffness of the structure, the amount of crush and the resulting deceleration were being judged, in some instances, as too stiff or not stiff enough for the driver. Much of this discussion centered on crash incidents for which no deceleration data were available from crash recorders (black boxes). In this paper, crash test dummy (Anthropomorphic Test Device ATD) results are compared for various idealized deceleration-time histories (deceleration pulses) that represent various structural crush characteristics. A crash velocity of 64.4 KPH (40 MPH) against a wall was used to represent a life threatening energy level.

In this paper, finite element shape optimization is used to determine the optimum air cleaner shape and rib design for low shell noise. Shape variables are used to vary the height and location of rib elements, as well as vary the shape of the air cleaner surfaces. The optimization code evaluates each design variation and selects a search direction that will reduce surface velocity. Sound power radiation is calculated for each optimized design using an acoustic code. Large reductions in shell noise were achieved by optimizing the shape of the air cleaner surface and rib design. Optimization of the rib pattern alone yielded a local optimization, as opposed to a global optimization that represented the best possible design.

The industry strategy for automotive safety systems has been evolving over the last 20 years. Initially, individual passive devices and features such as seatbelts, airbags, knee bolsters, crush zones, etc. were developed for saving lives and minimizing injuries when an accident occurs. Later, preventive measures such as improving visibility, headlights, windshield wipers, tire traction, etc. were deployed to reduce the probability of getting into an accident. Now we are at the stage of actively avoiding accidents as well as providing maximum protection to the vehicle occupants and even pedestrians. Systems that are on the threshold of being deployed or under intense development include collision detection / warning / intervention systems, lane departure warning, drowsy driver detection, and advanced safety interiors.

In the catalytic converter, the thermal conductivity of the insulation material (intumescent mat) placed between the ceramic catalyst and the metal shell is strongly dependent on the temperature, resulting in the solving of non-linear heat conduction equations. In this paper, the analytic solution for the steady heat flow in a cylinder with temperature dependent conductivity is given. Using this analytic solution for the mat and including convection and radiation at the converter skin, an analytical expression for calculating converter skin temperature is obtained. This expression can be easily incorporated in a Fortran code to calculate the temperatures.

Automotive occupant safety continues to evolve. At present this area has gathered a strong consumer interest which the vehicle manufacturers are tapping into with the introduction of many new safety technologies. Initially, individual passive devices and features such as seatbelts, knee- bolsters, structural crush zones, airbags etc., were developed for to help save lives and minimize injuries in accidents. Over the years, preventive measures such as improving visibility, headlights, windshield wipers, tire traction etc., were deployed to help reduce the probability of getting into an accident. With tremendous new research and improvements in electronics, we are at the stage of helping to actively avoid accidents in certain situations as well as providing increased protection to vehicle occupants and pedestrians.

Seat belts are the primary occupant-protection devices for vehicle crashes. Field statistics show that proper usage of seat belts substantially contributes to decreases in the fatality rate and injury level. To collect first-hand information regarding seat belt comfort and usability, a questionnaire survey was conducted. The most significant problems were found as belt trapping in the door, awkward negotiating with clothes, belt twisting, belt locking up, and difficulty to locate the buckle. The survey results indicated that drivers who are over 40 years old have more complaints than younger drivers. When the driver's age increases to 55 and above, belt pulling force and inappropriate and loose fitting of the belt on the body become major issues. Female drivers have more complaints than male drivers. Short statured drivers need both hands to pull and guide the retracting of the belt.

Since the late 1980s, Delphi Automotive Systems has been very involved with the practical development of a variety of Collision Avoidance products for the near- and long-term automotive market. Many of these complex collision avoidance products will require the integration of various vehicular components/systems in order to provide a cohesive functioning product that is seamlessly integrated into the vehicle infrastructure. One such example of this system integration process was the development of an Adaptive Cruise Control system on an Opel Vectra. The design approach heavily incorporated system engineering processes/procedures. The critical issues and other technical challenges in developing these systems will be explored. Details on the hardware and algorithms developed for this vehicle, as well as the greater systems integration issues that arose during its development will also be presented.

The objective of this paper is to impart the challenges presented and the solutions derived to transform an artist's rendering into a production driver's door switch to be used in the interior of a high profile sports car. The challenges took many forms throughout the process, from data translation and packaging, to the final decorative issues. The results are a finished product providing a new approach to automotive interior switch design. It incorporates a low profile, continuous plane keypad with “soft touch” feel, tactile feedback, and integrated back lighting.

Delphi has developed a second-generation Electronic Throttle Control system optimized for high volume applications. The Delphi system integrates several unique driver performance features, extensive security/diagnostics, and provides significant benefits for the vehicle manufacturer. For Model Year 2000, the Delphi ETC system has been successfully implemented on several popular SUVs and passenger cars built and sold around the world. The ETC driver features, security systems, and manufacturer benefits are presented as implemented on these Model Year 2000 applications.

Today, electrical/electronic systems like ABS/power brakes and electric power steering are all designed to enhance, not replace a mechanical function. If an electrical or electronic fault occurs, the function reverts to the base mechanical capability. Future E/E systems, such as steer-by-wire and brake-by- wire replace mechanical linkages with electrical or optical signals as in computer networks. While these systems offer many potential safety benefits, they will require different strategies for dependability, and as with any vehicle system, they will further require that dependability be an integral part of the overall E/E system design. This paper illustrates how by-wire systems drive different dependability requirements and discusses some key technologies that are emerging to meet these requirements.

Recent advances in dependable embedded system technology, as well as continuing demand for improved handling and passive and active safety improvements, have led vehicle manufacturers and suppliers to actively pursue development programs in computer-controlled, by-wire subsystems. These subsystems include steer-by-wire and brake-by-wire, and are composed of mechanically de-coupled sets of actuators and controllers connected through multiplexed, in-vehicle computer networks; there is no mechanical link to the driver. This paper addresses fundamental benefits and issues of steer-by-wire, especially those related to automated vehicle control and steering feel quality as perceived by the driver.

This work examines the development and implementation of a pulsing brake control system as part of a Forward Collision Warning (FCW) System for an Adaptive Cruise Control (ACC) prototype vehicle. The brake pulse is a likely candidate to be employed with visual and auditory cues in the event of an imminent collision alert level when the driver is not in ACC mode.

It is estimated that in the United States, nearly one quarter of all fatal automobile accidents involve a vehicle rollover. [1] In order to reduce fatalities and serious injuries, it is desirable to develop a sensing system that can detect an imminent rollover condition with sufficient time to activate occupant safety protection devices. The goals of a Rollover Sensing Module (RSM) are; 1 To accurately estimate vehicle roll and pitch angles 2 To reliably predict in a timely manner an imminent rollover 3 To eliminate false activation of safety devices 4 To function properly during airborne conditions 5 To be as autonomous as possible, not requiring information from other vehicle subsystems.

Electric power steering (EPS) is an advanced steering system that uses an electric motor to provide steering assist. Being a new technology it lacks the extensive operational history of conventional steering systems. Also conventional systems cannot be used to command an output independent of the driver input. In contrast EPS, by means of an electric motor, could be used to do so. As a result EPS systems may have additional failure modes, which need to be studied. In this paper we will consider the requirements for successful EPS operation. The steps required to develop diagnostics based on the requirements are also discussed. The results of this paper have been implemented in various EPS-based programs.

The purpose of this paper is to investigate occupant injuries which may be sustained during a single-event crash with known roll mechanism. The data was obtained from the weighted National Automotive Sampling System/ Crashworthiness Data System (NASS-CDS) for calendar years 1992 to 1996. The effect of number of rollover turns, roll direction, ejection and belt usage on driver injury responses was analyzed in single-event trip-overs. Trip-overs were chosen for the analysis because they account for over 50% of rollover crashes. The number of rollovers was divided in 3 categories: ¼ to ½ turn, ¾ to 1 turn and above 1 turn. Roll direction was either roll-left or a rollright along the longitudinal axis of the vehicle. Roll-left represents a roll with the driver side leading, while a roll right is with the right front passenger side leading. In the database used in this study, there were three times more belted drivers than unbelted.

The present paper reports on a study of the HVAC energy usage for an EREV (extended range electric vehicle) implementation of a localized cooling/heating system. Components in the localized system use thermoelectric (TE) devices to target the occupant's chest, face, lap and foot areas. A novel contact TE seat was integrated into the system. Human subject comfort rides and a thermal manikin in the tunnel were used to establish equivalent comfort for the baseline and localized system. The tunnel test results indicate that, with the localized system, HVAC energy savings of 37% are achieved for cooling conditions (ambient conditions greater than 10 °C) and 38% for heating conditions (ambient conditions less than 10 °C), respectively based on an annualized ambient and vehicle occupancy weighted method. The driving range extension for an electric vehicle was also estimated based on the HVAC energy saving.