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Technical Paper

“SHIFT-MATE” A Fuel Efficiency Monitor

The SHIFT-MATE is a dashboard mounted computer based device that cues a truck driver to shift more efficiently. Through electronic circuitry, key vehicle parameters are monitored, computed, then via graphic display, instructs the driver when to shift for improved fuel economy. The theory of operation is described in the text.
Technical Paper

“MBE 4000-A New Engine for the US Class 8 Truck Market”

Due to ever soaring fuel costs and even more stringent emission regulations which require more elaborate technical efforts and unfortunately lead to a negative trend on fuel economy as well, todays and future trucking business is extremely challenged. These facts create an urgent requirement for the engine manufacturer to offer an engine with an optimized cost-benefit-ratio for the trucking business. Mercedes-Benz, as the leader in the European commercial vehicle market - of which e. g. high fuel costs, long maintenance intervals and high engine power-to-weight ratios have always been key characteristics - has developed a new class 8 engine for the US market. The MBE 4000 is a 6 cylinder inline engine in the compact size and low weight category, but due to its displacement of 12,8 liters it offers high performance characteristics like heavier big block engines.
Technical Paper

“Dynamic Analysis of Cabin Tilting System of Heavy Trucks Using ADAMS-View for Development of a Software Interface for Optimization”

Design of a Cabin Tilting System of heavy trucks, a multi degree of freedom mechanism, is a challenge. Factors like adequate tilting angle, cabin styling, packaging, non interference of tilting system with ride comfort, forces in the system, specifications of the hydraulic system, are all very important for designing the system. Numerous considerations make the design process highly iterative hence longer design time. This paper primarily focuses on Kinematics and Dynamic analysis of the system in ADAMS and validation of system with real time testing results. Intention of this work is to make a parametric ADAMS model and link it to a Knowledge Based Engineering application to facilitate designer to quickly carry out design iterations for reducing development time. The Knowledge Based Engineering software is made using object oriented language called ‘Object Definition Language’ which has been developed using C and C++ software languages.
Technical Paper

practical design suggestions for users of Brazed Honeycomb Sandwich

SIX BASIC suggestions are offered on how to design for practical, producible, economical structures of brazed honeycomb sandwich. The author illustrates the application of some of these design suggestions and explores the step-by-step theoretical reasoning a designer might use to arrive at a satisfactory design for a hypothetical large missile wing. The final design of a honeycomb sandwich component must take into account the process as well as structural and configuration requirements.
Technical Paper

Zero Emission Vehicles

Recharging electric vehicles with photovoltaics (PV) results in a truer “zero-emission” vehicle. Other papers have discussed the complex issue of distributed tailpipe emissions versus displaced emissions from centralized generating stations. The use of PV to recharge electric vehicles avoids the distributed versus centralized emission controversy because PV has minimal environmental impact. Even when considering the total fuel cycle, including fuel extraction and plant construction, PV still retains a significant environmental advantage over conventional electrical generation technologies. This paper reviews total fuel cycle emissions and then addresses the use of PV to recharge electric vehicles. The data presented in this paper applies also to hybrid electric vehicles.
Technical Paper

ZF Retarder in Commercial Vehicles

This paper describes the ZF - Intarder, a wear-free vehicle brake for commercial vehicles. Qualities such as optimum weight saving, compactness, compatibility with all PTOs and no change in driveshaft length, are the results of a new development. Performance measurements demonstrate connection with engine cooling system. Field test measurements provide new information about frequency of use of various brake levels and electronic speed control. An evaluation of financial issues indicates advantages for operation.
Technical Paper

ZF EE Drive - Electric Drive System for Low-Floor Buses

The current environmental situation in urban areas is demanding new concepts of transportation and innovative vehicle designs. More environmentally-friendly means of transport represent an important feature in local public transport. Improvements in the environmental situation are to be achieved by increased transition from individual transport to public transport on the one hand, and by having more environmentally-friendly buses on the other. Electric drive, whether as diesel, hybrid or zero-emission drive, has a central role to play in this. This report gives a survey of their estimated technical characteristics and possible applications.
Technical Paper

You're Not Out There Alone: High-Tech and Other Aids for Your Career Planning and Management

Career development planning is critical to getting the most out of one's working years. It should start when one starts a career, but even if you start in mid-career, it's not too late. For those who haven't done it, career planning may seem difficult and confusing. Increasingly, your community library and state employment service agency provides valuable help in the form of computerized and manual aids to career planning and job-getting. This article follows Dave Brown, a mid-career engineer, through the career-planning process, introduces library and government resources to you and provides a list of computer programs relating to career planning and job getting.
Technical Paper

Yield Mapping of Soybeans and Corn Using GPS

Data obtained when harvesting with a combine equipped with a yield monitor were used to develop yield maps. A prototype yield monitor was developed that uses a combination of light emitters and receivers mounted in a rectangular frame. The monitor was mounted in the combine in the top of the clean grain elevator. As grain flows through the monitor, a voltage change proportional to light reduction was recorded. This voltage was then correlated to grain flow rate. At the same time, site-specific location was recorded using the global positioning satellites (GPS) system. The location data, yield monitor output, cutting width, and combine forward speed were stored in a spreadsheet format. The data were then used to prepare the yield maps.
Journal Article

Yaw Stability Enhancement of Articulated Commercial Vehicles via Gain-Scheduling Optimal Control Approach

In this paper, a gain-scheduling optimal control approach is proposed to enhance yaw stability of articulated commercial vehicles through active braking of the proper wheel(s). For this purpose, an optimal feedback control is used to design a family of yaw moment controllers considering a broad range of vehicle velocities. The yaw moment controller is designed such that the instantaneous tractor yaw rate and articulation angle responses are forced to track the target values at each specific vehicle velocity. A gain scheduling mechanism is subsequently constructed via interpolations among the controllers. Furthermore, yaw moments derived from the proposed controller are realized by braking torque distribution among the appropriate wheels. The effectiveness of the proposed yaw stability control scheme is evaluated through software-in-the-loop (SIL) co-simulations involving Matlab/Simulink and TruckSim under lane change maneuvers.
Technical Paper

Yaw Stability Control of Tractor Semi-Trailers

Tractor semi-trailer stability during emergency braking and steering maneuvers has been an issue that was improved through implementation of Anti-lock Braking Systems (ABS). Although some improvements have been achieved, the need for new control methodologies is evident from the number of accidents reported by NHTSA involving tractor semi-trailers. In this paper, a new control algorithm has been developed for improving the tractor semi-trailer stability through utilization of yaw moment, i.e., tire differential braking strategy. This new, multifaceted, adaptive control algorithm which allows the estimation of the unknown vehicle parameters through use of the adaptation laws is based on the Lyapunov Direct Method. A tractor semi-trailer model with four degrees of freedom was used to develop the control algorithm and the adaptation laws. The controller was implemented on a 2-axle tractor 1-axle van trailer in TruckSim 7©.
Technical Paper

Yaw Dynamics of Command Steered Multi Axle Semitrailer

This paper investigates the yaw dynamic behaviour of a seven axle tractor semitrailer combination vehicle developed by VRDE (Vehicle Research & Development). The semitrailer has four steerable axles which follow command steering law i.e. all axles of semitrailer are steered in a particular relation with articulation of tractor. A 4 dof (degree of freedom) linear yaw plane model was developed for this combination vehicle. Yaw response characteristics such as lateral acceleration, yaw rate and articulation angle for step and sine steer is obtained from this model. Effects of speed on the above parameters are also studied to the same steering inputs. Lateral tyre forces due to semitrailer steering at various speeds are estimated to understand its distribution on each axle. Steady state yaw rate and articulation angle gain are obtained to predict the understeer / oversteer behaviour of combination vehicle.
Technical Paper

Worldwide Truck Electronic Systems -- Trends for the 90s

It is the goal of this paper, to discuss the impact of electronics on modern day commercial vehicles an buses. Seen from the position of advanced engineering of an European commercial vehicle manufacturer, the emphasis will be placed on the mechanical-electronical system itself, rather than the electronics themselves. User friendly, logic protected systems will minimize operator unfamiliarity and misapplication and will offer not only component control, but shortly the integration of all of these subsystems in the total vehicle control. Total vehicle control will be the ultimate result, when the driver, the truck and the environment are brought together. Such vehicles will be more responsive, safer and easier to drive than today's commercial vehicles and buses and offer a cost effective utilization of these new technologies to the customer.
Technical Paper

Worldwide Survey and Characterization of Commercial Marine Fuels

The quality and availability of distillate fuels in the coming decades has become an increasing concern to the U.S. Navy. In response, the Energy Research and Development Office of the David Taylor Naval Ship Research and Development Center (DTNSRDC) has conducted a worldwide survey of commercial marine fuels. An effort was made to obtain 50 commercial marine fuel samples from various suppliers worldwide. The purpose of the survey was to assess the current quality of available fuels by analytically characterizing each of the fuel samples obtained. This assessment consisted of the measurement of more than 44 fuel properties. This paper contains a summary of the analytical results which were obtained. In addition, the current analytical results are compared with refinery specifications, with the current Navy specification, and with the results of a similar survey conducted in 1983. Finally, the resulting conclusions and recommendations are presented.