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The use of computer simulation of vehicle dynamics as a development tool has come into its own over the past few decades. “Simulated” testing on a computer makes possible a degree of control and repeatability that allows the automotive engineer to determine the influence of design variables on different aspects of dynamic performance in ways that would be difficult or impossible by experimental methods. One of the software tools receiving wide acceptance for simulating trucks and combination vehicles is Truck-Sim™. The attraction of this program arises in part from its foundation of truck modeling methods developed at the University of Michigan Transportation Research Institute over the past two decades, and the use of an advanced graphical user interface to make the software both easy to understand and easy to use by design and development engineers.

Abstract Three-dimensional patterns representing crosshatched plateau-honed cylinder bores based on two-dimensional Fast Fourier Transform (FFT) of measured surfaces were generated and used to calculate pressure flow, shear-driven flow, and shear stress factors. Later, the flow and shear stress factors obtained by numerical simulations for various surface patterns were used to calculate lubricant film thickness and friction force between piston ring and cylinder bore contact in typical diesel engine conditions using a mixed lubrication model. The effects of various crosshatch honing angles, such as 30°, 45°, and 60°, and texture heights on engine friction losses, wear, and oil consumption were discussed in detail. It is observed from numerical results that lower lubricant film thickness values are generated with higher honing angles, particularly in mixed lubrication regime where lubricant film thickness is close to the roughness level, mainly due to lower resistance to pressure flow.

This is an assessment of United States High Speed Guided Transit (HSGT) systems policy, vision, goals, and magnetic levitation development and commercialization technology. It includes a historical review of past magnetic levitation vehicle developments, a review of the present status of MagLev trains, and an outline of future conventional (EML) Electro Magnetic Levitation for speeds under 400 km/h; and, (SC) Super Conductive (EDL) Electro Dynamic Levitation for subsonic speeds approaching 900 km/h. Magnetic levitation transit technology has been under development in America since the United States Congress passed the 1965 High Speed Guided Transit Act (HSGT) which authorized the Department of Transportation to fund HSGT projects. Since this initial effort focused attention on the potential of the magnetic levitation concept for very high speed transit applications, this technology has been an ongoing development in Europe and Japan.

This paper presents a theoretical and experimental study on the determination of the efficiency of a hydraulic gear pump based on an analysis of the hydraulic fluid temperature at the inlet and outlet ports. Considering the thermodynamics and fluid mechanics equations, the steady state behavior of the gear pump is described for different wear conditions. The model establishes the relationship between the inlet and outlet temperatures and the main variables such as pressure, torque, flow, and angular speed and, consequently, the pump efficiency.

Review of various construction, equipment and organization factors considered in the design of new plant facility for fabrication of prototype earthmoving vehicles. Emphasis on eliminating existing problems and maximizing plant efficiency.

This paper provides a review of the solubility parameter theory and its application to predicting elastomer/fluid compatibility. Emphasis is placed on describing the theory and translating the results of swell data into a more easily understood method than has previously been used. Numerous solubility parameters arc presented as well as swell test details. The swell data results are then used to determine solubility parameters which, upon comparison with other fluid or elastomer solubility parameters, determine compatibility. This procedure is especially important because it enables the results of swell tests to be used to identify elastomer/fluid compatibility of molecularly complex fluid additives or special elastomer mixtures.

A new type of screw pump has inherent design features (e.g. balanced design, low bearing loads, wear-adjustable rotors, low rubbing loads, …) which may allow efficient, reliable, and maintainable operation in numerous applications, particularly for pumping low-viscosity fluids. Initial tests on an 87 gal/min prototype pumping lubricating oil at pressures up to 500 lb/in2 and speeds up to 1800 rev/min achieved good performance with little wear over 3400 hours of operations. Performance projections indicate volumetric efficiencies of 50 percent should be reached using the existing prototype pumping 1200 lb/in2 water in one stage.

Pulse width modulation (PWM) has been used to alter the performance of on-off hydraulic control valves to make them perform as proportional type flow control valves. Nonlinear performance resulting from time delays in valve switching as well as valve wear due to continuous cycling continue to persist as operational problems. This paper examines a new technique called modified PWM control. The method was found to provide accurate control with a minimum of valve chatter.

The objective of this paper is to delineate the importance of pictures, i.e., graphical models, in documenting and communicating the high level functionality of a complex system, primarily for embedded software requirements and specifications. An overview is given of various graphical techniques and methodologies for modeling complex systems. The aspects (advantages and disadvantages) relating to different categories of modeling are outlined. Discussion of complex systems extends beyond the functional/software aspects of product design to both process and project modeling. The author shares personal observations and experiences with modeling, and tools used.

Future fuels for internal-combustion engines will be derived increasingly from solids such as coal. An alternative to processing coal into liquid fuels is the direct use of solid coal by reciprocating, internal -combustion engines. Specific applications which would be especially suitable for solid fueled engines consist of stationary power plants, marine propulsion systems, and railroad locomotives. Agricultural, construction and mining equipment are examples of other possible applications. The objectives of this study were to review past research on the development of solid coal fueled engines and, from this review, to identify major technical problems and current research needs. The objectives also included comparing the energy usage of several fuels. This comparison indicated a possible 25% energy advantage by directly using solid coal fuels as opposed to using synfuels.

Applications of active suspension control for both on-highway and off-highway vehicles are reviewed. Suspension design is evaluated in terms of ride vibration exposure and road/terrain handling. Active, semi-active, and slow-active suspension types are described in terms of their performance capabilities. Finally, numerous design concepts and their application to a wide range of ground vehicle types (i.e, truck, automotive, agricultural, and construction) are described.

Japan's truck production in 1962 accounted for 70% of total vehicles manufactured. Of this, 85% consisted of compacts and midget models for use by private enterprises and over congested narrow roads. Because of severe operating conditions on unpaved bumpy roads, large payloads require sturdier vehicles and higher ratios of power to weight than do those in other countries. Passenger bus transportation is expanding and extending service distances. Practically all large vehicles are diesel powered, but smaller ones are gasoline powered. The modernization of highways will bring larger and speedier models with more engine horsepower for longer distances.

This paper will review the current truck and bus steering column technology and marketplace in Europe. European specifications, norms and customer driven performance criteria are discussed. New technical solutions coming onto the market place are creating increasing diversity in techniques applied to steering column design and these are examined. An overview presentation of the Pailton Engineering past and current product and some of their development ideas looks at the two markets, truck and bus, separately. The concept of pedestal floor mounted and bulkhead mounted steering columns is considered. Mechanical clamping and air unclamping are explained and the use of electrically adjustable columns in trucks and buses is discussed. The concept of steering systems engineering to include the steering column as a vital integrated member in a steering system instead of a single stand alone item is discussed.

Automobile accident reconstruction and vehicle collision analysis techniques generally separate vehicle collisions into three different phases: pre-impact, impact and post-impact. This paper will concern itself exclusively with the modeling of the impact phase, typically defined as the time the vehicles are in contact. Historically, two different modeling techniques have been applied to the impact of vehicles. Both of these techniques employ the impulse-momentum formulation of Newton's Second Law. The first relies exclusively on this principle coupled with friction and restitution to completely model the impact. The second method combines impulse-momentum with a relationship between crush geometry and energy loss to model the impact. Both methods ultimately produce the change in velocity. ΔV, and other pertinent information about a collision.

Abstract Numerous researchers are committed to finding solutions to the path planning problem of intelligence-based vehicles. How to select the appropriate algorithm for path planning has always been the topic of scholars. To analyze the advantages of existing path planning algorithms, the intelligence-based vehicle path planning algorithms are classified into conventional path planning methods, intelligent path planning methods, and reinforcement learning (RL) path planning methods. The currently popular RL path planning techniques are classified into two categories: model based and model free, which are more suitable for complex unknown environments. Model-based learning contains a policy iterative method and value iterative method. Model-free learning contains a time-difference algorithm, Q-learning algorithm, state-action-reward-state-action (SARSA) algorithm, and Monte Carlo (MC) algorithm.

For over a decade engine manufacturers have been pursuing alternative fuel strategies for vehicle powertrains. First came the discussion of fuel selection. Next, whether or not these alternative fuels can provide the utility offered by traditional diesel. Finally, the footrace of technology and hardware to provide utility, reliability and maintainability with the use of alternative fuels. Now the day has come where many alternative fuels are a practical reality. The body of this paper will discuss the utilization of natural gas as an alternative fuel. This paper targets the fleet operator in an effort to provide a single source of information in a concise format. A discussion of emission standards, engine operational strategies, component technology, fuel characteristics and the utility of using natural gas as a fuel will be addressed. The understanding of present and future engine development is of great importance to a successful fleet operation.

Emission standards derived to protect the environment have driven engine manufacturers to accelerate their efforts in engine emission development in order to meet the mandated standards. This paper will outline the current and upcoming emission standards, the technology involved in accomplishing the requirements and the solutions to in-service engines meeting their emission standards. The paper targets the fleet operator to provide a single source of information in an effort to alert them to upcoming requirements and what can be expected when specifying equipment for procurement. The technology discussed in this paper varies in its application for several engine makes and models. Since technology transfers from application to application it is vital that these ideas and concepts be explained.

When faced with an engine failure, the initial problem to solve is how to repair it. This translates into the choices of; in-house or external repair. With current labor rates as they are, most operators cannot afford to rebuild an engine themselves. Parts acquisition, shop space, technical knowledge, tooling and the fact that in-house rebuilds do not carry a warranty all act to sway the operator to external sources for assistance. An additional, but equal, concern is how much will the engine cost to repair. The body of this paper will discuss the technology involved in producing remanufactured engines. Topics covered are cost analysis, remanufacture specifications and process and fleet operational logistics using remanufactured engines.

Reports published by Gulf R&D Co. and Battelle Columbus Laboratories under contract to the Coordinating Research Council's APRAC project group CAPE-24 were reviewed. Both studies failed to verify the accuracy of polynuclear aromatic hydrocarbon (PNA) emission measurements from heavy-duty diesel engines. Thermal decomposition and chemical reactions of the PNA occur in raw exhaust at temperatures above 500°F. Therefore, pipes which transfer exhaust to dilution tunnels can significantly reduce the apparent emission values. Dilution tunnel conditions have comparatively little effect on PNA measurements. However, vapor traps are required behind particle filters to assure complete collection of 4-ring PNA compounds. Guidelines are presented for controlling and testing sampling systems for accurate PNA emission measurements.

This paper describes a forward looking on-board vehicle detection and driver alert system that provides a distance indication and alert tone to the driver. The system, called VORAD (Vehicular On-board Radar), is the first of its kind to be fielded. The system can be programmed to function in different operating modes, allowing customization to the user's requirements. Some possible operating modes include simply providing an alert to the driver, providing following distance indication measured in seconds based on the vehicles' speeds, or providing following distance measured in feet. The VORAD System also has optional features to enhance its usefulness, including a blind spot alert system and a built-in event recorder. The blind spot system provides additional information to the driver regarding the presence of vehicles in his blind spot for use in making lane changes.