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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.

Over the past several years the Institute of Electrical and Electronic Engineers (IEEE) Standards Association has developed standards for the 5.9 GHz Dedicated Short Range Communications protocols, also known as Wireless Access in Vehicular Environments. These standards consist of IEEE 1609 as well as an amendment to the IEEE 802.11 standard or 802.11p. The 1609 standards were published for Trial Use and these as well as the 802.11p draft have been implemented in a variety of test beds to provide lessons learned and feedback into the standards working groups. Based on ongoing testing, the protocols display a strong capability to address the requirements of crash avoidance and transportation mobility applications. The corresponding test results provide information necessary to update the standards after the first trial phase as industry moves toward commercial implementations.

Hundreds of millions of micromachined, piezoresistive Manifold Absolute Pressure (MAP) sensors have been produced to reduce pollution and improve fuel efficiency in engine control systems. Other vehicle applications for micromachined pressure sensors include monitoring turbo pressure, barometric pressure, fuel tank leakage, fuel rail pressure and tire pressure. Exhaust gas recirculation and even door compression for side impact detection are employing micromachined silicon pressure sensors. Piezoresistive pressure sensors have dominated the automotive market to date. Practical micromachined capacitive pressure sensors have recently been developed and could replace the piezoresistive sensor in many applications. This paper will examine the advantages of both pressure sensing technologies, and discuss applications that an inexpensive capacitive pressure sensor will open up.

Despite the general similarity of U.S. and European heavy trucks, there are differences in design properties that affect braking and turning performance. A European tractor-semitrailer was studied for the purpose of comparing its properties to those of U.S. vehicles and assessing the comparative performance. Mass, suspension, and braking system properties of the European tractor and semitrailer were measured in the laboratory and on the proving ground. Turning and braking performance qualities were evaluated by computer simulation and by experimental tests. In turning performance the European combination had a 9 percent advantage in rollover threshold, compared to a generic U.S. vehicle with properties that were in the midrange of U.S. design practice. Higher suspension roll stiffness and higher chassis weight on the European tractor and semitrailer accounted for the higher threshold.

Collision warning systems (CWS) are a relatively new technology to reduce or mitigate motor vehicle rear-end and side impact collisions. This study compared available police-reported crash experiences of 6,143 CWS-equipped heavy trucks with the experiences of 383,058 heavy trucks without CWS. Data were from the Motor Carrier Management Information System (2000-2002). Results suggest that CWS-equipped trucks had a significantly lower proportion of crashes involving other moving vehicles and a significantly lower proportion of multiple vehicle crashes compared to trucks without CWS, (40% vs. 49%, p<0.0001; 62% vs. 67%, p<0.004 respectively). These changes are the first crash-data based evidence that supports the design effect of CWS. However, more studies are needed to determine the specific impacts of CWS on heavy truck crashes.

For several staged collisions, results obtained with closed form reconstruction calculations and with a computerized step-by-step procedure are compared with measured responses. A refined, closed-form reconstruction procedure is defined, derivations of the analytical relationships are outlined and detailed results of sample applications are presented. Closed form calculation procedures for estimating impact conditions became a topic of interest in relation to the development of an automatic starting routine for iterative applications of the Simulation Model of Automobile Collisions (SMAC) computer program. The accuracy of initial estimates of speeds determines the total number of iterative adjustments of SMAC that are required to achieve an acceptable overall match of the evidence. Since a high degree of success was achieved in the refinement of such calculation procedures, the end product, by itself, is considered to be a valuable aid to accident investigations.

In order to evaluate the THOR-50M as a front impact Anthropomorphic Test Device (ATD) for vehicle safety design, the ATD was compared to the H3-50M in matching vehicle crash tests for 20 unique vehicle models from 2 vehicle manufacturers. For the belted driver condition, a total of fifty-four crash tests were investigated in the 56.3 km/h (35 mph) front rigid barrier impact condition. Four more tests were compared for the unbelted driver and right front passenger at 40.2 km/h (25 mph) in the flat frontal and 30-degree right oblique rigid barrier impact conditions. The two ATDs were also evaluated for their ability to predict injury risk by comparing their fleet average injury risk to Crash Investigation Sampling System (CISS) accident data for similar conditions. The differences in seating position and their effect on ATD responses were also investigated.

This paper describes a general purpose computer graphics interface for performing detailed two- and three-dimensional studies involving the dynamic response of humans and vehicles during the pre-crash, crash and post-crash phases of a motor vehicle accident. Specifications are provided for human, vehicle and environment models which can be constructed and analyzed using the interface. The requirements of analysis methods which may be incorporated into the interface are examined, and several examples are provided. Finally, the paper illustrates how the interface is used for creating high-level animations to view the resulting human and/or vehicle motion on various output devices such as computer displays, printers, plotters and video tape recorders.

A class of heavy truck vehicles, characterized primarily by high centers of gravity, was studied using analysis and computer simulation to identify and understand the relationship between directional and roll stability of such vehicles during steady turning maneuvers. Findings of the computer-based study suggest: (1) directional instability (yaw divergence) is possible for such vehicles during steady turning while operating at elevated speeds on horizontal road surfaces, (2) yaw divergence will lead to rollover in the absence of corrective steering action and/or reduced speed, and (3) the primary mechanism responsible for precipitating yaw divergent behavior in such vehicles is the nonlinear sensitivity of truck tire cornering stiffness to vertical load acting in combination with typical heavy truck fore/aft roll stiffness distributions. In addition, the influences of roadway superelevation and driver steering control as contributors to vehicle stabilization are examined and discussed.

Trucks can carry heavy load and when applying the brakes during for example a mountain downhill or for an abrupt stop, the brake temperatures can rise significantly. Elevated temperatures in the drum brake region can reduce the braking efficiency or can even cause the brake system to fail, catch fire or even break. It therefore needs to be designed such to be able to transfer the heat out of its system by convection, conduction and/or radiation. All three heat transfer modes play an important role since the drum brakes of trucks are not much exposed to external airflow, a significant difference from disk brakes of passenger cars analyzed in previous studies. This makes it a complex heat transfer problem which is not easy to understand. Numerical methods provide insight by visualization of the different heat transfer modes. Presented is a numerical method that simulates the transient heat transfer of a truck drum brake system cooldown at constant driving speed.

Paper describes analysis of the design process of modern automotive LPG and CNG containers. Over decade experience in the field of both computer based analysis as well as in the real conditions testing has been collected and presented in the paper. Authors present the potentials of modern FEM methodologies in the optimization and production of lightweight steel containers. It has been proved that the most sophisticated numerical analysis have to be followed by the construction verification, particularly considering direct exposure to fire. Bonfire test have become obligatory for both liquid and compressed gases containers. Properly chosen fire protection system, together with the adequate level of quality of materials applied for its production together with proper directing of the gas flowing out from safety devices are the essential factors defining gas containers fire safety.

The reproduction of the vehicle motion is a crucial element of accident reconstruction. Apart from the position of the center of gravity in an inertial coordinate system, the vehicle heading plays an important role. The heading is the sum of the yaw angle and the vehicle body side slip angle. In standard vehicles, the yaw angle can be determined using the yaw rate sensor and the wheel speeds. However, the yaw rate sensor is often subject to temperature drift. The wheel speed signals are forged at low speeds or due to slip. These errors result in significant deviations of reconstructed and real vehicle heading. Therefore, an intelligent combination of these signals is required. This paper describes a fuzzy system which is capable to increase the accuracy of yaw angle calculation by means of fuzzy logic. Before the data is applied to the fuzzy system, it is preprocessed to ensure the accuracy of the fuzzy system inputs.

When two pieces of heavy equipment interact, jolting and jarring can occur. During haulage truck loading for example, there is a chance that the operator of one or both pieces of the equipment will experience jolting and jarring. Additionally, a jolt can occur when an off highway equipment operator drives over a road defect or inadvertently strikes a berm. Aside from the operators, there is seldom anyone else that witnesses the interaction and can accurately describe the extent of the jolting. This makes it difficult for health and safety managers to address jolting and jarring. The devices and software described in this paper constitute a method for installing “black boxes” called Shox Boxes onboard equipment that already have a GPS system onboard. The resulting configuration provides an objective assessment of jolting and a chance to determine the root causes of it.

The research on connected vehicles has attracted much interest of governments and research institutions in these days. As researchers who have been deeply intrigued, we are particularly interested in investigating the lane changing issues of connected buses when exiting bus stops. In order to examine the utilities of both the buses and social vehicles in a connected environment, we employ the game theory to analyze the interactions between them. A two-player, non-cooperative, non-zero-sum game model was built in this paper. We analyzed 5 different scenarios for bus exiting at bus bay stops and curbside bus stops. The payoffs considered in the game model were mainly from the perspective of safety and time. Besides the commonly studied safety issues caused by collisions, we supplement the existing literature by adding on non-collision injuries caused by improper driving behaviors (e.g. excessive acceleration).

Today, active dynamic control systems for commercial vehicles, offering improved safety, are frequently discussed. Yaw stabilising systems are based on theories from passenger car implementation, yet roll stabilisation - probably introduced in the near future - requires increased knowledge of rollover mechanics. Static analysis, providing steady state rollover threshold (SSRT), is the most common approach. Nevertheless in a rolling vehicle, kinetic energy is always present, deteriorating roll stability, invalidating the analysis. A simple method determining the dynamic rollover threshold (DRT) is therefore introduces in this paper. DRT is the worst case measure of roll instability: the conditions are necessary but not sufficient for rollover.

Driver visibility from commercial vehicles is often an issue in post-accident litigation. While the visibility through the windows of most vehicles is restricted due to the required structure of the vehicle itself, most manufacturers and users incorporate a series of mirrors to enhance driver visibility and to reduce blind spots. The challenge for an engineer is to first demonstrate what the driver could see to a reasonable degree of engineering certainty, and then to convey this information in a form that is easy for the lay person to grasp. This paper outlines procedures for calculating and modeling the driver visibility from commercial vehicles. The primary techniques presented require access to the vehicle, although the paper also presents techniques by which visibility can be analyzed through photogrammetry and 3-D computer models, both for the vehicle and for any mirrors incorporated onto the vehicle.

In recent years research and development on ‘compatibility’ in the area of collision safety has been proceeding. It is a big issue how to prevent an increase in the severity of injuries of occupants in a weaker vehicle. With regard to FUP (Front Underrun Protector), we consider it possible to further lessen the severity of injuries of car occupants by simultaneously studying the requirement for collision safety on the passenger car as well as the requirement for strength stipulated by the ECE regulation. Therefore we develop the study method for collision safety structure using an optimizing method.

An experimental methodology is proposed to measure the rollover propensity of road tankers when subjected to lateral perturbations derived from steering manoeuvers. The testing principle involves subjecting a scaled down sprung tank to the elimination of a lateral acceleration, to analyze its rollover propensity as a function of various vehicle's operational and design parameters. Initial acceleration is generated through putting the scaled tank on a tilt table supported by a hydraulic piston. The controlled release of the fluid in the hydraulic system generates a perturbation situation for the tank, similar to the one that a vehicle experiences when leaving a curved section of the road and going to a straight segment. Durations for the maneuver and initial tilt angles characterize both the corresponding intensities of the steering maneuver.

A long standing problem with heavy vehicle stability has been rollover. With the higher center of gravity, heavier loads, and narrower tracks (as compared to passenger vehicles), they have a lower rollover stability threshold. In this paper, a rollover stability control algorithm based on a two-degrees-of-freedom (DOF) and a three-DOF vehicle model for a two-axle truck was developed. First, the 3DOF model was used to predict the future Lateral load Transfer Rate (LTR). Using this LTR value, the dynamic rollover propensity was estimated. Then, a robust output feedback gain control rollover stability control algorithm based on the combination of active yaw control and active front steering control was developed. A H₂/H∞/poles placement multi-objective control strategy was developed based on the 2DOF reference model.

In automotive design and development, there are different stages for product design. In this fast changing scenario product design, digital verification of design (CAE), physical validation of the product and launching of the same in short time is important in product development life cycle of any new generation vehicle. This paper proposes a new approach towards development of a green-field platform for commercial vehicles by improving reliability of CAE and thereby reducing the need for prototype testing and hence shortening development cycle and costs - we call it “Hybrid Mule”. This Hybrid Mule has complete design intent under-body and engine-house while upper-body is made of simple representative tubular space frame. FRP skin panels are attached to this space frame to create a safe environment for test-driver. FRP skin also provides early feel of styling in running condition and evaluates basic ergonomics and visibility.