Search Results

An air cushion restraint system has been available to the public on certain model passenger cars since January 1974. In response to this opportunity to obtain field experience, the National Highway Traffic Safety Administration has established a nationwide reporting network and investigative capability for accidents involving air-bag equipped cars. The reporting criteria for accidents require that the car be towed as a result of the accident, or that a front-seat occupant was injured, or that bag deployment occurred. The principal objective is to obtain the injury-reducing effectiveness of this restraint system in the total accident environment. This environment encompasses “towaway” accidents resulting in bag deployment and non-deployment. Definitive results are expected at the conclusion of the study. This paper summarizes the experience during the first year of the program, during which time the rate of accident occurrence was far less than originally expected.

Airbag systems have been part of passenger car and truck programs since the mid-1980's. However, systems designed for medium and heavy duty truck applications are relatively new. The release of airbag systems for medium duty truck has provided some unique challenges, especially for the airbag sensing systems. Because of the many commercial applications within the medium duty market, the diversity of the sensing environments must be considered when designing and calibrating the airbag sensing system. The 2003 Chevrolet Kodiak and GMC TopKick airbag sensing development included significant work, not only on the development of airbag deployment events but also non-deployment events – events which do not require the airbag to deploy. This paper describes the process used to develop the airbag sensing system deployment events and non-deployment event used in the airbag sensing system calibration.

A 3-D video sensor designed for in-vehicle operation is presented in this paper. This sensor enables improved occupant protection according to the Federal Motor Vehicle Safety Standard (FMVSS) 208 and beyond. Interior sensors integrated in current occupant protection systems are especially designed for Occupant Classification (OC). However, these interior sensors do not measure the distance between the head and the air bag module. As a result, the air bags deploy independently from the occupants' Out-Of-Position (OOP) status in crash situations. On the contrary, the sensor presented in this paper overcomes this shortcoming by providing dynamic Out-Of-Position Sensing (OOPS) capabilities in addition to occupant classification. The requirements of dynamic OOPS are discussed and an appropriate test device and test procedure are described. Furthermore, the paper presents the sensor principle, the hardware architecture and algorithms for image data processing.

This paper focuses on the analysis and evaluation of acoustical design criteria to produce a plausible 3D sound field solely via headrest with integrated loudspeakers at the driver/passenger seats in the car cabin. Existing audio systems in cars utilize several distributed loudspeakers to support passengers with sound. Such configurations suffer from individual 3D audio information at each position. Therefore, we present a convincing minimal setup focusing sound solely at the passenger’s ears. The design itself plays a critical role for the optimal reproduction and control of a sound field for a specific 3D audio application. Moreover, the design facilitates the 3D audio reproduction of common channel-based, scene-based, and object-based audio formats. In addition, 3D audio reproduction enables to represent warnings regarding monitoring of the vehicle status (e.g.: seat belts, direction indicator, open doors, luggage compartment) in spatial accordance.

The significance and the number of vehicle safety features enabled via connectivity continue to increase. OnStar, with its automatic airbag notification, was one of the first vehicle safety features that demonstrate the enhanced safety benefits of connectivity. Vehicle connectivity benefits have grown to include remote software updates, data analytics to aid with preventative maintenance and even to theft prevention and recovery. All of these services require available and reliable connectivity. However, except for the airbag notification, none have strict latency requirements. For example, software updates can generally be postponed till reliable connectivity is available. Data required for prognostic use cases can be stored and transmitted at a later time. A new set of use cases are emerging that do demand continuous, reliable and low latency connectivity. For example, remote control of autonomous vehicles may be required in unique situations.

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.

A great deal of data is available concerning accident simulation tests with test dummies or cadavers but in comparison there is very little material on tests involving living volunteers. This paper describes crash tests and sled tests with human test persons and Hybrid II dummies. To obtain a realistic accident simulation the tests were run with standard Audi 80 vehicles fitted with the standard seat belt systems. The results clearly demonstrate that none of the test persons sustain any kind of physical injury at a precisely defined level of accident severity (vehicle-to-vehicle crash at a collision speed of approx. 30 mph). In some cases considerable differences are revealed between the loadings imposed on the dummies and the human test persons.

A mathematical simulation of the operation of a compressed-gas airbag system is developed. A system was built and tested, and the analysis is evaluated on the basis of these tests. Included in the study are nonideal gas effects, manifold and diffuser effects, bag stretch, bag leakage, and overpressurization of the passenger compartment. Interaction between a single rigid object and the bag is also considered. A correlation between bag pressure and the force it generates is obtained. This allows the development of an analytic model for determining the motion of a single rigid mass interacting with a dynamically inflating airbag mounted in a moving vehicle. An application of the model to study rebound of the occupant from the airbag is presented.

This paper describes a BAseband Radar (BAR) sensor for radar braking application; an early version of the BAR concept was reported previously as a precollision sensor for air bag activation. In this paper we show how the normally wide effective beamwidth of the BAR is narrowed by using interferometry in conjunction with a novel delay line digital processor scheme. The beamwidth of the breadboard system spans a traffic lane width at 45 meters. The paper describes the details of the BAR sensor front-end and preliminary test results sponsored by the U.S. Department of Transportation and the Institute for Telecommunication Sciences.

Simplified mathematical modeling has been employed to investigate the relationship between automobile forestructure energy absorption and the restraint loads applied to passengers during a 30 mph barrier collision. A two-massmodel was developed and validated to compute restraint loading from a given passenger compartment deceleration. The effect of various deceleration curves, representing forestructure modifications, is reported. A “constant force” restraint system is also evaluated.

The Federal Motor Vehicle Safety Standard or FMVSS 208 requires passenger cars, multi-purpose vehicles, trucks with less than unloaded vehicle weight of 2,495 kg either to have an automatic suppression feature or to pass the injury criteria specified under low risk deployment test requirement for a 1 year old dummy in rearward and forward facing restraints as well as a forward facing 3 and 6 year old dummy. A convertible child seat was installed in a sub-system test buck representing a passenger car environment with a one-year- old dummy in it at the passenger side seat and a passenger side airbag was deployed toward the convertible child seat. A MADYMO model was built to represent the test scenario and the model was correlated and validated to the results from the experiment.

Choosing the correct thermoplastic for an instrument panel application requires a thorough understanding of the environmental and performance conditions. In the case of a high speed event, such as an airbag deployment or a knee bolster intrusion, standard static tensile properties may not adequately define the material performance. The engineer needs to understand the materials sensitivity to high strain rate extremes. The subject of this paper is the enhancement of part performance through the testing and knowledge of material performance over a range of strain rates.

The automotive industry has seen an increase in the application of passenger side hidden airbag door technology. The hidden airbag door presents several challenges to the design and analysis Engineer. Airbag deployments function as a system of components, acting in concert. Design optimization requires investigating the individual parts and their interactions as a structure. This paper is a case study using Finite Element Analysis and Data Acquisition as a guide, to provide design optimization and predict deployment performance.

Newer automobiles have complex dynamic and stability controls due to regulations, competition, and safety concerns. More systems require testing at the subcomponent level to ensure proper operation in the final vehicle assembly. Many of the stability and navigation features originally designed for aircraft components are now being incorporated into automobiles. Certain types of motion test simulators were originally designed for testing aircraft sensors as: gyroscopes, inertial navigation systems (INS), inertial measurement units (IMU), and attitude heading and reference systems (AHARS) This same type of equipment is now used for automotive testing as: airbag fuse sensors, anti-skid sensors, rollover sensors, vehicle stabilization systems, active suspension sensors, and navigation systems.

Accelerator-type sled systems have been very useful to the automotive industry for many years. These systems have allowed engineers to effectively evaluate a safety component in a frontal crash environment without having to conduct a full-scale crash test. While accelerator-type sleds are an excellent tool for frontal crashworthiness development, the energy required to simulate a side impact or lateral pole impact test is just a small fraction of the total capacity of the system. In light of this, a project was undertaken to develop a system which incorporated many features of the current accelerator-type sled system, but was designed to simulate non-frontal crash test cases. This paper describes the development and test applications for the new sled system. The operating theory and general design is similar to current accelerator-type sled systems, although the new system has been scaled down significantly.

A national survey of 1500 adults and 500 adolescents identified the major factors impacting on seat belt use. Particular attention was paid to the important role interpersonal interaction and instruction plays instigating and reinforcing seat belt use. The importance of interpersonal interaction was assessed relative to the impact of demographic variables, perceptions of seat belt comfort and convenience, attitudes concerning seat belt use, and the establishment of the seat belt “habit.”

Vehicle restraint system design is a difficult optimization problem to solve because (1) the nature of the problem is highly nonlinear, non-convex, noisy, and discontinuous; (2) there are large numbers of discrete and continuous design variables; (3) a design has to meet safety performance requirements for multiple crash modes simultaneously, hence there are a large number of design constraints. Based on the above knowledge of the problem, it is understandable why design of experiment (DOE) does not produce a high-percentage of feasible solutions, and it is difficult for response surface methods (RSM) to capture the true landscape of the problem. Furthermore, in order to keep the restraint system more robust, the complexity of restraint system content needs to be minimized in addition to minimizing the relative risk score to achieve New Car Assessment Program (NCAP) 5-star rating.

This paper describes the results of 13 tests simulating a frontal impact against a fixed barrier at 50 km/h and 25 g. The results showed a marked increase in the severity of injuries with increasing age and more frequent chest injuries than head and spinal injuries. The tests were made with two types of restraint systems, both of which seemed equal in occupant protection.

Belt systems are an appropriate means for realizing effective occupant protection. There are technical possibilities known, e.g. belt force limiters and preloading devices, which permit extreme safety requirements to be fulfilled by means of purposive coordination of the belt system to the structural deformation behaviour. The results presented here provide an example. It is at present difficult to evaluate the effectiveness of an occupant restraint system. One reason among others is the lack of an uniform complex Evaluation Index. In this paper, a suggestion is made concerning this problem: Introduction of the Evaluation Index EI.

This paper presents the results of a test program comparing the performance of the CAUSFIX (originally known as CANFIX) and the Uniform Child Restraint Anchorage (UCRA) systems to the conventional Australian anchorage system of adult belt and top tether. Each anchorage configuration was subjected to both 45 and 90 degree simulated side impacts. The performance of the attachment systems was assessed using the TNO P3/4 dummy in both a rearward facing restraint and a forward facing restraint. Assessment was based on peak head acceleration and displacement. The results indicate that both the CAUSFIX and the UCRA system can provide improved protection for children in side impacts. The CAUSFIX system was found to offer the greatest potential for improvement. The results of this work are significant to the current debate concerning the proposed draft international standard for universal anchorage systems.