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Ride quality of medium truck became a very important factor in the suspension design, due to the demand of more comfortable ride of passengers. This study describes how to determine and evaluate design parameters related to the chassis suspension system with time and frequency analysis. The spring stiffness and damping force of the chassis suspension system were obtained by observing the vertical acceleration PSD. The simulation was carried out on various road profiles, which was suggested by ISO. The pitching motion of the medium size truck was observed to improve the ride quality. A computer simulated truck model was constructed using DADS, a commercial dynamic analysis software, in order to simulate the truck motions. From the result of the sensitivity analysis of suspension parameters, it was concluded that the spring and the shock absorbers affect the pitching of the vehicle. In order to validate the computer simulated truck model, a physical prototype was constructed and tested.

Several lead-free alloys have been studied for potential use in electronics by the National Center for Manufacturing Sciences(NCMS) Lead Free Solder Consortium that ended in 1996. Since then, one of these alloys has been studied using an existing product in order to determine the viability of Lead Free Vehicle Electronics. Design, supply chain, manufacturability, and reliability data for the electronics components and system are a part of this paper.

Hybrid electric transit vehicles offer many improvements over conventional diesel fueled buses through the application of new and emerging technologies not previously applied to the bus environment. However, these changes require the manufacturers of hybrid buses to go to great lengths to insure that the industry does not take a step backwards and end up burdened with unreliable vehicles which do not perform as advertised. This paper will describe Nova BUS's approach to developing a reliable hybrid electric transit bus through a comprehensive test and evaluation process. The substantial changes in technologies, drive train configurations and potential failure modes inherent in the design of hybrid vehicles require a fresh look at the way bus designs are tested and validated. The ultimate goal of this process is to provide a quality product to the market which offers the full range of advantages which are possible using hybrid technology.

Nearly all segments of the automotive business are actively involved in pollution reduction and environmental activities as a daily part of doing business. Environmental responsibility is a process of continuous improvement; a manufacturer never arrives at a point where further environmental activity is unnecessary. An environmental or “green” metric enables a manufacturer to measure and compare environmental performance over time and among alternative proposed product designs and manufacturing processes.

This paper addresses each of four phases regarding the life of electronic products including design, production, consumption, and end of life/recycling. It assesses each phase, its impact on the environment and relates them to ISO 14000 (International Standards Organization 14000 Environmental Management Systems: General Guidelines on Principles, Systems and Supporting Techniques).

The paper shows the completely new designed concept for electronics in the Mercedes-Benz Actros. The basic rules are explained, and on the example of the engine management the advantages of such an entire-vehicle promise are shown. At last it is pointed out, that the presented concept will be the basis for future developments on integration of electric's and electronics.

Rapid growth in the number of electronic systems on today's commercial vehicles has resulted in the proliferation of information displays. Systems for driver message centers, mobile communications, and fleet management are using flat panel displays for information management. Liquid crystal, vacuum fluorescent, and LED are commonly used display technologies. These devices are often segmented displays and are useful in presenting numeric or iconic data. Recent driver information systems have used multi-line character displays to present alphanumeric information. The use of a small graphic array display offers the benefit of presenting either alphanumeric or graphic information. Small graphic arrays that use liquid crystal technology are beginning to appear in vehicles. Graphic array displays using electroluminescent technology are also available.

The next generation in Europe of city bus control systems design will focus on system data exchange, power control and diagnostic for vehicle electronics. This will be the basis for improved functionality of city vehicles in order to fulfill any government regulations, reduced development cost, and allow an increased flexibility in the new functions capability. The focus of this paper is to review the principle design structure of ACTIA's new multiplex control system; door control, lights control, extension to the J1939 standard, instrumentation and their applications.

Every year the trucking industry demands lighter weight and lower cost truck components. But it is very difficult to achieve both these targets. This paper describes the example of a suspension system design which was conducted by computer simulation, so called CAE. The computer simulation by FEM was used completely to decide the detailed shape of each part. This paper also introduces a casting method to strengthen the aluminum alloy cast using high pressure during casting. By using this method, products have a precise metallographic structure. As a result, both the development cost and period were reduced by over the half the time required of the current system and lighter and strong parts were created.

A generic articulated heavy vehicle model, applied to a tractor semi trailer combination is modelled on an approach characterised by simplicity. Yet, the handling characteristics accuracy serves well within the frequency domain of interest. Possessing the capacity of performing in real time simulation up to the limits of yaw and roll stability, its simplicity derives advantages offering effective parameter variation possibilities at an elevated educational level. As an example, better understanding of the expected wheel angle deviation from the current wheel spindle angle is achieved through an extension of the model. Validated against field experiments of lane change manoeuvring under high friction conditions up to the limit of roll stability, it also compan?s well against a more complex computer model.

An In-Vehicle Data Acquisition/Monitoring Device (Data Logger) has been developed to be used for evaluating the performance of alternators during vehicle operation. It can be linked to other controllers and electronic devices for exchange of information through the use of a serial communication port. By utilizing a microcontroller, eight analog and three TTL level signals are measured and recorded in non-volatile EEPROM memory devices. The system measures temperatures of critical components, system voltage and rotational speed.

The flexibility of flat bed trailers is shown to be an important consideration in determining the static roll threshold for a loaded Class 8 tractor trailer. The development of an easy to use static roll threshold model using Microsoft® Excel's nonlinear equation solution capability provides a tool that should be useful to the trailer designer, dock loading manager and the traffic safety manager responsible for the training of drivers. It can be seen for low stiffness flat bed trailers that the trailer torsional stiffness is a more important parameter than typical suspension or tire stiffness. Further, even for “stiff” flat bed trailers the use of the rigid body roll criteria (T/2h) or the 2-D “planar” model can produce significant error in many practical loading configurations.

A closed-loop articulated vehicle-driver model, incorporating the path errors, lateral accelerations of the two units and the rate of steering, is proposed to study the directional control behavior of the driver. The closed-loop driver-vehicle model is formulated upon integrating the yaw-plane model of a five-axle articulated vehicle and a comprehensive driver model. The driver model, incorporating the delays associated with the limb movement and muscle activities, is developed with an objective to minimize the lateral acceleration of vehicle, and the lateral position and orientation errors between the previewed and the actual path of the tractor. Various parameters required to describe the driver's contributions are identified through minimizing a weighted performance index subject to an array of limit constraints established from the reported data.

Relative rollover conditions of a heavy vehicle are analyzed to establish an array of potential dynamic rollover indicators towards development of an early warning device. A relative roll instability indicator defined as Roll Safety Factor (RSF) is proposed and shown to be a highly reliable indicator regardless of vehicle configurations and operating conditions. The correlation of various potential rollover indicators with the roll safety factor are then investigated for a 5-axle tractor semi-trailer combination using a comprehensive directional dynamic analysis model to determine the reliability of the proposed indicators over a range of operating conditions. The indicators are further examined in terms of measurability, lead time, and potential for application in an early warning system. The study shows that the trailer lateral acceleration and axle roll angles are closely correlated with the RSF.

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.

An automotive Coolant Level Sensor has been developed which eliminates the diffusion of water through the housing. This enables the Coolant Level Sensor to survive in high temperature/pressurized environments.

The PACCAR Digital Message Center (DMC) is a truck computer with a 40-character vacuum-fluorescent display in the dash panel. Designed to OEM specifications, it serves to integrate the many data display requirements of heavy trucks into a single device. To meet customers' ergonomic expectations, consideration was given to information navigation, the display technology, the number of keys, the size of each key, the key labeling, and the keys' tactile feedback. The product was designed to be used by operators (clock/alarm, messaging, fuel economy information), service technicians (diagnostics and maintenance) and fleet managers (trip recording and fuel management). Configurability and software upgradeability were also important considerations.

This technical paper discusses the need for a retrofit program using improved technology to eliminate the use of axle nuts having the potential for failure. A review of the history of wheel end problems on highway trailers is also a portion of this presentation. Knowledge of newly perceived operational conditions will be presented along with recommendations on how they might be addressed. With review of this material, those interested in highway safety will be apprised of up-to-date information that will enable appropriate remedial action to be initiated.

Presented in this paper is a new multiplex communications technology that economically permits a two-way transfer of information (data) between a tractor and trailer(s) through the standard SAE J560 connector. Power Interval Communications Technology (PICT) is a single wire, serial communication system that is transmitted over the existing turn signal circuit. This paper will show the basic approach of the PICT system and the major advantages it offers. PICT allows the use of the current SAE J560 connector to provide an in-cab trailer ABS fault indication. PICT, transmitted over the turn circuit, is compatible with all tractor and trailers, old and new, because this circuit is common to all vehicles. PICT is a very economical solution because no twisted pair communications wiring is required, no in-line switched communications techniques are required, no sophisticated interface circuitry is required, and no additional connections are required between the tractor and trailer.

A major task of road and airfield maintenance for transportation departments in the Northern United States and in cold regions globally is snow removal. In addition, there is a service industry built on snowplow equipped light trucks to remove snow from vehicle serviceways and parking lots. Thus, a source of stresses on a truck frame are the forces applied by the plow. Unfortunately, very little research has been performed to provide design models that will predict these forces. In this paper, both theoretical and experimental work on developing expressions for snowplow forces will be discussed.