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Viewing 1 to 30 of 106038
2012-06-13
Technical Paper
2012-01-1537
In industrial automotive transmissions, several noises can't be avoided such as gear rattle and gear whine noises. Indeed they result from the choice of gear technology. They just can be reduced by an appropriate design. It is widely acknowledged that gear whine noise is mainly due to transmission error, which depends on many parameters such as driveshaft deflection, gear stiffness and operating torque. All these parameters are not necessarily well-known, which may sometimes result in the choice of a gear geometry that doesn't minimize transmission error. That can lead to customer claims once the vehicle is manufactured. To cope with whine noise customer claims, we investigated a statistical gear optimization method. The principle is to use whine measurement data base on benches to find the best geometry against whine noise after a statistical treatment. The main advantage is that it is not necessary to know precisely all the parameters involved in whine noise.
1981-09-01
Technical Paper
PHOTO
1990-02-01
Technical Paper
900255
Multi-dimensional code has been developed to simulate the effect of geometry on mass flow rate and flow pattern in the induction system of an internal combustion engine. The unsteady compressible Navier-Stokes equations in general curvilinear coordinates are solved by a new method of lines. In the method of lines, the governing equations are spatially discretized by a finite difference approximation and the resulting system of ordinary differential equations is integrated. As a time integration scheme, we newly propose to use the rational Runge-Kutta scheme in order to efficiently simulate the flows in the induction system. The domain-decomposition technique is introduced so that body-fitted structured grid can be easily generated for such complex geometry as a real intake port shape. The present code is applied to 2 and 3 dimensional steady flows in intake port/cylinder assembly with a valve.
1990-02-01
Technical Paper
900251
MarK J. Jennings, Thomas Morel
An important aspect of calculation of engine combustion chamber heat transfer with a multi-dimensional flow code is the modeling of the near wall flow. Conventional treatments of the wall layer flow employ the use of wall functions which impose the wall boundary conditions on the solution grid points adjacent to solid boundaries. However, the use of wall functions for calculating complex flows such as those which exist in engines has numerous weaknesses, including dependence on grid resolution. An alternative wall modeling approach has been developed which overcomes the limitations of the wall functions and is applicable to the calculation of in-cylinder engine flows. In this approach the wall layer flow is solved dynamically on a grid spanning a very thin boundary layer region adjacent to solid boundaries which is separate from the global grid used to solve the outer flow.
1990-02-01
Technical Paper
900253
D. H. Gibson, W. A. Mahaffey, T. Mukerjee
This paper details the development of a mathematical model to simulate the incylinder processes in the Caterpillar 1.7L Diesel engine and the results obtained during compression stroke and early part of the combustion stroke. The model includes accurate representation of the geometry of the 1.7L combustion chamber via Body Fitted Coordinates (BFC) which conform to the shape of the piston-dish and cylinder. Also included are the combustion model and evaporation model. This 3-D model predicts average cylinder pressure and temperature variations with degree crank angle which are in good agreement with Caterpillar measurements for this engine.
1990-02-01
Technical Paper
900249
M. Shimotani, M. Hibino, T. Yamamoto, T. Nonami
A voice recognizer for automotive application which controls hands-free car telephone using voice has been developed. To ensure high recognition performance in noisy environments, a pitch synchronous analysis method and utterance detection method adaptable to noisy environments have been adapted to the voice recognizer. A digital signal processor (DSP) for pitch synchronous spectrum analysis and a micro processor for pattern matching and controlling the system have been used as the main components, and the recognizer has been compactly designed for automobile use.
1990-02-01
Technical Paper
900250
Harald Bochmann, Kurt Wiedemann
A new type of FM receiving system is introduced which eliminates most of the well known typical distortions due to the properties of the mobile radio channel. The system consists of several antenna elements mounted on a car and a special receiver which combines their individual RF signals in order to minimize distortion. In contrast to conventional antenna diversity systems, the new system does not switch between the available antenna elements, instead the signals are modified in amplitude and phase, and then added to each other. The resulting shape of the receiving pattern of the antenna system is directed in such a way that the S/N ratio is maximized and the effect of interference minimized.
1990-02-01
Technical Paper
900248
Robert Broadway, Ali Fotowat, Russel Killingbeck, Omar Saleh, Prasanna Shah, Enjeti Murthi
As cellular phone usage increases, solutions which not only meet the exact specifications, but are also economical in size, weight, and power dissipation must be found. This paper presents one such solution using a six chip set designed to meet the AMPS and TACS specifications. System requirements, architecture, as well as board level considerations and layout are discussed. In addition, the effects of shielding are presented along with test results.
1990-02-01
Technical Paper
900252
Kang Y. Huh, I-Ping Chang, Jay. K. Martin
- Three different models, the law-of-the-wall, a modified law-of-the-wall, and an approximate one-dimensional solution to the energy equation are compared for the spatially-resolved prediction of engine heat tranfer. The multidimensional hydrodynamic code KIVA is used for the fluid mechanic simulation. Two different engine geometries are studied; one being a pancake-shaped chamber, and the other a bowl-in-piston geometry. The comparisons are done for a range of initial conditions of gas flow. Rates-of-pressure-rise were also varied to represent rates typical of those encountered in motored engines, and those found in fired engines. Comparisons with experimental results show that the heat transfer predictions using the law-of-the-wall may be in error when source terms such as the transient, work and chemical energy terms have a significant effect in determining the temperature profile in the boundary layer.
1990-02-01
Technical Paper
900244
John E. Haug, David E. Borth, Kevin L. Kloker, Carol W. Wu
Abstract With the introduction of compact disk players to automotive entertainment systems a new standard of in-car sound reproduction quality has been set. To ensure that the level of performance that CD offers is not compromised it has been suggested that digital signal processing techniques be used to perform the usual audio processing. By performing as much of the AM and FM radio processing as possible using digital signal processing (DSP) it is possible to integrate many entertainment system functions into a single programmable unit. This paper describes a technique for decoding the stereo multiplex signal from the FM detector into the left and right audio channels in a way that is particularly amenable to DSP implementation. A brief description of such an implementation using the Motorola DSP56001 digital signal processor IC and DSP56ADC16 A/D converter IC is included.
1990-02-01
Technical Paper
900247
Ramesh Sivakolundu, Abdul Aleaf
Abstract The current automotive ETR market trend indicates that modularization of the various radio features both in terms of hardware and software would result in a highly integrated and flexible design that meets the price/performance of the low,mid and high end ETR's. This document deals with the various modular features and partitioning that would be required to implement them. Core oriented microcontrollers provide the required flexibility and performance. The intent of this paper is to describe a cost effective implementation of a modular ETR by the Microcontroller Applications Group at National Semiconductor Corporation. The COP888xx family of full feature, fully static microcontrollers provide the required core architecture and efficient system solution.
1990-02-01
Technical Paper
900241
Mitoshi Sasaki, Kazuo Takayama
Automobile radio receivers must perform well under varying reception conditions, and increasingly sophisticated mobile audio gear requires better sound quality for AM and FM reception. Fujitsu Ten have developed a mobile AM tuner IC to meet these requirements. The IC features an RF-AGC circuit which enables the receiver to tune in remote signals while rejecting strong local signals, a variable IF bandwidth control circuit to demodulate broader bandwidths, and a new tracking circuit for the RF tuning circuits and local oscillator. These features enable the received frequency range to be expanded (to 1710 kHz) and to improve the quality of AM stereo reception. The techniques developed for the new mobile AM tuner IC are described below.
1990-02-01
Technical Paper
900242
Munehiro Karasudani, Shinji Miyata, Kazuyuki Doi, Naotoshi Higashiyama
1 ABSTRACT Currently, digital audio source such as a compact disk (CD) and a digital audio tape (DAT) has come to be mounted in cars to complement the sophisticated audio system . To mount these new functions in the limit set space, however, the conventional source such as the FM/AM tuner must be built more compact and lightweight. On the other hand, to view the FM/AM tuner perspective from the standpoints of set design and manufacture, there are various problems such as given below. Set variations are flung from those for the U.S.A. and Europe to those for Japan. It is difficult, if not impossible, to design the set designer for each of these set variations because of the limited designer availability. Also, amid the tendency for world production base to be spread and increasingly numerous, high quality level is of the utmost importance for audio sets no matter where are manufactured. This paper describes an effective solution to these problems.
1990-02-01
Technical Paper
900239
Satoru Kato, Masahiro Torikai
The Vacuum Fluorescent Display (VFD), being a self-emissive display device featuring high luminance and excellent readability, has become widely used for automotive applications. The ability to drive it at 12V and to adjust the luminance with the duty cycle, give the VFD high consideration, especially for the display in the car audio system. The number of display segments for the car audio system has increased to more than 50. Adding new functions to the car audio system will increase the required number of display segments. In the 12V static drive system, the number of display segments determines, and equals, the number of driver integrated circuit (IC) output bits required. An increase in the number of anode terminals, required by the increase in display segments, will result in increases in system cost, assembly complexity, space-related problems, etc. This paper reports on attempts taken to solve these problems.
1990-02-01
Technical Paper
900240
Eric Danstrom
Several methods of indirectly measuring total harmonic distortion (THD) in a power amplifier by measuring characteristics of the input and output waveforms are presented. The relative accuracies of each method is discussed. While the emphasis is on practical methods that can be implemented in a automobile car radio, sensing THD levels within 1% of the target level can be realized.
1990-02-01
Technical Paper
900464
Ken Nakagawa, Tatsuhiro Ootsubo
It is becoming more and more complex and time consuming to have a newly developed vehicle meet the safety requirement these days. On the other hand, with the aid of computers and software technology, detailed crash simulation are possible. ISUZU MOTORS LTD. has applied these to the passenger car from the early stages of development in order to optimize the car's behavior in the 35MPH frontal barrier test. Crash simulations were performed by using the detailed full vehicle FEM model and the crash simulation program PAM-CRASH. This simulation focussed on the collapsing mode of the front structure, especially on the front of the side rails and the attached parts. Section forces, accelerations, and deformed shapes were investigated and optimized to improve energy absorption. The effect was confirmed by the experimental barrier test. This procedure contributed greatly to reducing the time required for development as well as the number of prototype vehicles needed.
1990-02-01
Technical Paper
900465
Hiroyuki Matsumoto, Masafumi Sakakida, Koji Kurimoto
This paper describes the behavior of a driver side occupant restrained by airbag system on a passenger vehicle at a frontal barrier crash. In order to secure effective occupant protection at collisions, it is necessary to conduct close examination into the movement of steering system due to the rearward movement of dashboard as well as vehicle deformation characteristics, generally for vehicles whose crash space at engine compartment is small. The authors examine the influence of these two parameters on occupant injury indices using MADYMO 2D computer simulation program. As a result, it is found important to model the axial collapse and the rotation of steering system in the vertical plane caused by dashboard deformation, in order to achieve good correlations between experiment and simulation. It is demonstrated.
1990-02-01
Technical Paper
900470
Paul Green, John Boreczky, Seung-Yun (Sylvia) Kim
To develop easy-to-use control panels, it is essential to measure driver performance, compare it with behavioral specifications, modify the design based on driver feedback, and then retest. Rapid prototypers help engineers do this quickly. This paper identifies the I/O capabilities, ease of use, ability to record user behavior, and real-time performance for several prototypers. Two example HyperCard prototypes are described here. The first, a car clock, shows how HyperCard can vary button size and location, labeling, auditory feedback, and the mapping of switches to system functions. The second, a car radio, shows that continuous controls and digitized sound can be handled.
1990-02-01
Technical Paper
900466
J. C. Liaw, A. C. Walton, J. C. Brown
Use is made of the KRASH program to simulate a simplified car-into-barrier impact. A step-by-step modelling technique is illustrated whose application at an early stage in the design process, allows an understanding of the contribution of individual components to the overall crash-performance of a vehicle.
1990-02-01
Technical Paper
900461
Kichiro Abe Hidekazu Nishigaki, Shin-ichi Ishivama, Michitaka Ohta, Michito Takagi, Fujio Matsukawa, Masanori Mizuno
This paper describes a calculating method to predict the quasi-static collapsing behaviors of spot-welded closed-hat section curved beams under axial compression. The overall deformat ions and the local buckling modes of beams were calculated using a geometrical model. Force-displacement relations were predicted by a elastic-plastic structural analysis method using the ‘plastic hinge’ concept. Collapsing tests were made on beams which are differenting section size, rotation angle, and metal sheet thickness. Comparisons between the calculated and experimental results of deformed shapes of beams, the local buckling modes and the force displacement relations are discussed.
1990-02-01
Technical Paper
900460
Yoshiaki Ohkami, Kenji Takada, Kazuyoshi Motomura, Munemasa Shimamura, Hitohiro Tomizawa, Matsuo Usuda
This paper describes the collapse characteristics of thin-walled curved beams with closed-hat section under axial compression load. Static and dynamic collapsing tests have been carried out on beams different in section size, curved angle, thickness and yield point. We clarify the influences of the initial bending curvature of beam axis, size of section and gauge of metal sheets on the gloval deformation mode, local buckling mode and load-deformation curve from the test results. These results of collapsing tests provide the necessary feedback for the structural components design and aid in the verification of analytical predictive techniques.
1990-02-01
Technical Paper
900463
Tomohiko Ariyoshi
To analyze the rear end crash of a motor vehicle using a beam-element model, it is important how to model the upper body panel members such as rear doors or rear quarters. This paper describes the method of modeling each panel member into a beam element considering the “effective areas” in each member section. The panel member is cut into several sections along its longitudinal axis. Applying the thin-shell buckling theory and experimental analysis to each section, “effective areas”, which withstand up to the yield stress when the panel member is subjected to longitudinal compression, can be selected. With the section characteristics of the “effective areas”, a beam element for the panel member is defined. The results of the calculation by this method showed a good correlation to the experimental results of three kinds motor vehicles with the body deformation mode or crash length etc.
1990-02-01
Technical Paper
900462
Tomasz Wierzbicki, Wlodek Abramowicz
CRASH-CAD is a commercially available computer aided design package that specifically addresses design problems of components and sub-assemblies of automotive bodies subjected to crash loading. The program is fully interactive and leads an engineer in several steps towards an improved crashworthy design. The objective of the present paper is to give a theoretical foundation of this new computer program and demonstrate its various capabilities. CRASH-CAD enjoys unparalleled modelling simplicity. It requires only basic cross-sectional dimensions of a given member and a discretization into Superfolding Elements is done automatically. The current version of CRASH-CAD is applicable to prismatic members subjected to predominantly axial compressive loads.
1990-02-01
Technical Paper
900473
Hisao Kishi, Takao Asami, Shinya Ishikawa, Toshiyuki Itoh
This paper describes the Multi-AV System featured in the 1989 model Nissan Cedric, Gloria, and CIMA. It is composed of a navigation system and an audio-visual system. The former system tracks the location of the vehicle and shows it on a CRT map display. This standalone navigation system has been achieved using a map-matching technique along with a terrestrial magnetic field sensor and wheel speed sensors installed at the wheels. Information on hotels, golf courses, Nissan dealers and other items can be obtained. A CD-ROM is employed as the memory. The audio-visual system consists of a radio, cassette deck, CD player, and TV. The Multi-AV System combines the practicality of a navigation function with the entertainment capabilities of an audio-visual system to satisfy diverse needs.
1990-02-01
Technical Paper
900472
W. Dwayne DeBardelaben
Anyone implementing a vehicle navigation system that displays a user's position (via a cursor) relative to a given map, must contend with the issues of cursor placement, map orientation, and efficient map updates. The objective of this paper then is to first briefly present a number of approaches to the first two subjects (cursor placement and map orientation) with the option of a NORTH UP,CURSOR CENTERED (NUCC) presentation being chosen as best. Secondly, an easily implemented, flexible algorithm for controlling this type of display that includes map display boundary checks, quick panning and scrolling, arbitrary position data entry, and more will be presented along with coding (pseudo-code) examples. Inherent in the presentation of this algorithm is a discussion of the third issue of efficient map updates.
1990-02-01
Technical Paper
900475
Hiro Hiroyasu, Masataka Arai
The objective of this paper is to summarize experimental results which were previously reported by the authors and to derive many useful empirical equations concerning the diesel fuel sprays. The empirical equations for break-up length, spray angle, spray tip penetration and drop size distribution of the diesel sprays are introduced to discuss the internal structure of the spray. According to the effect of injection pressure and ambient pressure on the break-up length and drop size of the diesel spray, the spray structure can be divided into two categories; incomplete and complete sprays. The equations which express the break-up length and mean diameter of the incomplete and complete sprays were obtained using different techniques according for the dominance of one or more break-up mechanisms.
1990-02-01
Technical Paper
900474
Mark Hodapp
Abstract LED technology offers many reliability advantages over incandescent bulbs for the backlighting of automotive telltales. However, up until recently, LED solutions were not practical due to the high cost. In order to get sufficient legend brightness, automotive designers were forced to either use expensive multiple chip LED indicators or expensive metalized reflectors. This paper describes how a single chip LED indicator can be used to illuminate a 15 mm by 15 mm automotive telltale with an inexpensive white molded plastic optical cavity. Using this indicator and cavity, luminous sterances of over 1000 cd/m2 are achievable in the center of the legend and luminous sterances of over 400 cd/m2 are achievable in the corners of the legend. The paper describes a complete telltale solution including this new LED indicator, the reflector design, and optical test results.
1990-02-01
Technical Paper
900468
Douglas J. Brandt, Craig S. Gray, Allen B. Rayl
Abstract With the increased complexity of today's motorsports vehicles, the driver has access to a significant amount of vehicle data. Although this information is available, presenting critical data so the driver can quickly and easily interpret the information is a challenging task. This paper describes the design and implementation of an electronic digital liquid crystal display for motorsports applications.
1990-02-01
Technical Paper
900467
Hideaki Kobayashi, Eiji Kawa, Yung S. Chen, Kajiro Watanabe, Hiroyuki Ishizuka
This paper describes how to realize an accurate, compact, and economical fuel gauge by the pneumatic method for deformed and flexible tanks which shake and vibrate, whose attitude changes and in which liquid sloshes and the temperature changes. The basic concept employed in the pneumatic method involves the use of the ideal gas law. The volume of liquid in a closed tank can be obtained by subtracting the volume of gas in the tank from the tank capacity. To determine the gas volume, both a reference tank attached to the main tank and the main tank were subject to the sinusoidal displacement. From the equations based on the dynamics of the pressure in the main tank derived from the ideal gas law and flow of gas thought a pipe, relations were obtained that gave the gas volume in the main tank from the filter pressure signals in the both tanks.
1990-02-01
Technical Paper
900469
Richard C. Berry
Application-independence is the key to reusability and universal interfacing of dot matrix display subsystem designs. Special design rules can be applied during the development of these systems that promote the removal or localization of all application-specific components, resulting in display products that can be applied without modification to many varied applications.
Viewing 1 to 30 of 106038