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Viewing 91 to 120 of 8879
2015-04-14
Technical Paper
2015-01-0631
Cuiping Feng, Zhihong Dong, Yuliang Yang, Chaoxing Xie, Kai Wang
Abstract The vibration theory and dynamic vibration absorber (DVA) theory is presented. Based on the finite element analysis and rigid-flexible coupling analysis, combined with an engineering example, drive shaft analysis model including DVA was established. The effects of DVA's parameters on the dynamic response of the main system, such as frequency ratio, mass ratio, installed position and damping ratio were studied independently as an experimental design. The studied conclusion was used to optimize DVA directionally, and optimization of multiple factors was completed. In this paper, the optimization design of a drive shaft with DVA was completed and a final test evaluation was implemented, that the rigid-flexible coupling analysis method was verified.
2015-04-14
Technical Paper
2015-01-0635
Changxin Wang, Wenku Shi, Zhijun Guo, Meilan Liu
Abstract For the roll vibration problem of a Truck, a 4-DOF roll vibration model of its front suspension system was built. According to dynamics theory, the complex modal vibration modes of the model were all obtained. At the same time, the frequency response functions of frame roll angle acceleration, the relative dynamic load of wheel and the suspension dynamic deflection were respectively presented. Then their characteristics were respectively researched. In the process of characteristic analysis, a new system parameter was proposed, which is the space ratio of the space between suspensions of left and right sides and the wheel track of the front axle (space ratio in short). At last, the influence of system parameters on the vibration transmission property was also reserached, which included the natural frequency of the frame, the damping ratio, the stiffness ratio, the mass ratio, the rotational inertia ratio and the space ratio.
2015-04-14
Technical Paper
2015-01-0618
Zhihong Dong, Ying Sun, Guitao Zhu, Shihu Wang, Jian Zeng, Yuliang Yang
Abstract Based on the modal frequency response theory and experiment, the installation layout evaluation and structural optimization method for SIS(side impact sensors) installation position is studied. Establish the finite element model including B-pillar, roof and floor with local constraint. Than study the key parameter's influence on the frequency response analysis results, and the simulation results are correlated by experiment. In view of the installation layout requirements of side impact sensors, the structure optimization method for installation position of side impact sensor is put forward. The optimal scheme is confirmed by the finite element analysis, and a final experimental verification was implemented by a real vehicle test.
2015-04-14
Technical Paper
2015-01-0617
Jie Zhang, Xiao Chen, Bangji Zhang, Lifu Wang, Shengzhao Chen, Nong Zhang
Abstract This paper demonstrates time response analysis of the mining vehicle with bounce and pitch plane hydraulically interconnected suspension (HIS) system. Since the mining vehicles working in harsh conditions inducing obvious pitch motion and the hard stiffness of suspensions leading to the acute vibration, the passive hydraulically interconnected system is proposed to provide better ride comfort. Furthermore, the hydraulic system also increases the suspension stiffness in the pitch mode to prevent vehicle from large pitch motions. According to the hydraulic and mechanical coupled characteristic of the mining vehicles, a 7degrees of freedom (7-DOFS) mathematical model is employed and the state space method is used to establish the mechanical and hydraulic coupled dynamic equations. In this paper, the vehicles are subjected to straight line braking input, triangle block bump input applied to the wheels and random road tests.
2015-04-14
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Abstract This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one.
2015-04-14
Technical Paper
2015-01-0216
Ping-Min Hsu, Ming Hung Li, Kuo-Ching Chang
Abstract This paper discusses noise filtering in an autonomous emergency braking (AEB) system with a sensor fusion between a millimeter wave (MMW) radar and a camera. Three kinds of noise, namely twice harmonic noise, ground noise, and specular reflection noise, are then filtered. The former is caused by the reflection of a radar wave between a target object and the MMW radar; therefore, one of the sensing distances would be twice as longer as one of others. An object featuring this characteristic is treated as the noise and filtered. Next, detecting a ground metal as the target object generates the second noise with a focus of car-like objects. That is, an object-with the sensing distance from the MMW radar being smaller than that from the camera by a threshold value-is taken as the ground metal noise and ignored. Moreover, the third noise happens when there is a radar wave reflection between an object and its surroundings.
2015-04-14
Technical Paper
2015-01-1087
Juergen Greiner, Martin Grumbach, Albert Dick, Christoph Sasse
Abstract Market trends clearly demonstrate the ongoing worldwide acceptance and success of modern automatic transmission solutions (AT, CVT, DCT) in both passenger cars and light trucks. This success is based on the further development of the driving comfort, shifting dynamics and - most important - the fuel consumption reduction modern automatic transmission systems offer. First, key driveline parameters such as overall spread and number of ratio's are to be discussed. The optimum spread for the fuel efficiency is in the range of about 8 to 9 and can typically be achieved by 8 to 10-speed transmissions. This is because modern gasoline or diesel-engines have a rather flat characteristic fuel map. Therefore the inner efficiency of the future transmissions becomes increasingly important.
2015-04-14
Technical Paper
2015-01-0430
Frédéric Kihm, Andrew Halfpenny, Benoît Beaum
Abstract As part of the design and validation of engine-mounted components, it is essential to define the vibratory mechanical environment in which these components will operate. This is required in order to optimize the reliability of such components subjected to loading from both the engine and road profile, while minimizing development costs and time scales. This paper presents a methodology that superimposes a swept sine on a power spectral density of acceleration in order to evaluate the mechanical durability of engine mounted or gear box mounted components. The first step in the process is to obtain the wave form of the dominant engine orders by extracting the deterministic signals from the random process using an order tracking method in the time domain. The second step is to assess the fatigue damage and extreme response spectra of a Swept-Sine-On-Random profile.
2015-04-14
Technical Paper
2015-01-0831
Wonah Park, Youngchul Ra, Eric Kurtz, Werner Willems, Rolf D. Reitz
Abstract The low temperature combustion concept is very attractive for reducing NOx and soot emissions in diesel engines. However, it has potential limitations due to higher combustion noise, CO and HC emissions. A multiple injection strategy is an effective way to reduce unburned emissions and noise in LTC. In this paper, the effect of multiple injection strategies was investigated to reduce combustion noise and unburned emissions in LTC conditions. A hybrid surrogate fuel model was developed and validated, and was used to improve LTC predictions. Triple injection strategies were considered to find the role of each pulse and then optimized. The split ratio of the 1st and 2nd pulses fuel was found to determine the ignition delay. Increasing mass of the 1st pulse reduced unburned emissions and an increase of the 3rd pulse fuel amount reduced noise. It is concluded that the pulse distribution can be used as a control factor for emissions and noise.
2015-04-14
Technical Paper
2015-01-1673
Seunghyun Lee, Yoonwoo Lee, Sungmoon Lee, Han Ho Song, Kyoungdoug Min, Hoimyung Choi
In this study, the correlation between the maximum heat release rate and the vibration of the diesel engine block was derived, and a methodology for determination of maximum heat release rate was presented. In order to investigate and analyze the correlation, the bench test and the real road vehicle test were carried out with a 1.6 l diesel engine. By varying the engine speed, load and main injection timing, the vibration signals were measured on engine block and was analyzed through continuous wavelet transform. It is shown that the maximum heat release rate had stronger correlation with magnitude of vibration rather than peak in-cylinder pressure and maximum in-cylinder pressure rise. A specific bandwidth, vibration signal of 0.1~2 kHz, was affected by the variation of heat release rate. The vibrations excited by combustion were lasted over 50 CAD, however, the signals in period of 35 CAD after start of injection had dominant effect on maximum heat release rate.
2015-04-14
Technical Paper
2015-01-1123
Jiangwu Zhang, Donghao Liu, Haisheng Yu
Abstract A novel single-mode compound split hybrid transmission with a compound planetary gear set and two brakes has been studied, which has more freedom of control to increase the system efficiency. System dynamics and matching performance of the driveline including a compound planetary gear set for a single-mode hybrid electric vehicle are numerically investigated. The multi-degrees of freedom torsional vibration model for the full-hybrid vehicle driveline with the power split device is established by MATLAB/Simulink. For comparison of the natural characteristic, eigenfrequencies and mode shapes are determined with the aid of a further simplified single-track mechanical model under different operation modes. Then, numerical simulations of dynamics and kinematics of the driveline and the compound planetary gear set are carried out.
2015-04-14
Technical Paper
2015-01-1122
Kengo Yabe, Toru Inagaki, Takashi Kondo
Abstract Seat vibration when a vehicle is idling or in motion is an issue in automobile development. In order to reduce this vibration, dynamic damper or inertia mass is widely used. These countermeasures increases vehicle's weight and causes bad fuel-efficiency. Some new ways to reduce the vibration without weight increase are needed. One of that is the floating seat. Seat vibration has been reduced by controlling seat resonance frequencies. In order to control resonance frequency, the structures of the seat-mounting unit are replaced with floating structures using rubber bushings. It was demonstrated that partially replacing the mounting unit with floating structures makes it possible to control the resonance frequencies of the entire seat. The issue of balancing vibration reduction with strength and durability and crash safety performance caused by the fitting of rubber bushings to the seat-mounting unit was addressed using stopper structures optimized for each type of input.
2015-04-14
Journal Article
2015-01-1579
Jun Nakahara, Koji Yamazaki, Yusuke Otaki
There exist some cars which ride performance become less comfortable on smooth road. If vibration transmissibility of suspension system on such a vehicle is evaluated by means of equivalent dynamic stiffness, it is found that the increase of storage stiffness deteriorates the vibration transmissibility of suspension due to the steep rising of hysteresis on wheel-stroke to wheel-load curve when excitation amplitude become small. To improve the ride-comfort performance on smooth road, therefore, the rising shape of wheel stroke curve due to hysteresis components, such as shock-absorber, ball-joints and rubber bushes, should be adjusted to prevent the increase of storage stiffness at small amplitude of suspension stroke. For investigating the hysteresis characteristics of these components, appropriate simulation models, which can reproduce their characteristics accurately, must be installed in the vehicle model and their parameters have to be determined with sufficient accuracy.
2015-04-14
Journal Article
2015-01-1597
Kazuto Yokoyama, Masahiro Iezawa, Hideyuki Tanaka, Keiichi Enoki
Mitsubishi Electric has developed a concept car “EMIRAI 2 xEV” that features an electric vehicle (EV) powertrain for safe, comfortable, and eco-friendly driving experiences in the future. The body of vehicle was exhibited during Tokyo Motor Show 2013 for the first time. xEV is a four-wheel-drive EV that has three motors: a water-cooled front motor and two air-cooled rear motors with integrated inverters. Rear wheels can be driven independently. The degrees of freedom of the actuation can realize improved maneuverability and safety. The vehicle is also equipped with an onboard charger with built-in step down DC/DC converter, an EV control unit, a battery management unit, and an electric power steering. All of the instruments are developed in Mitsubishi Electric Corporation. Motion control systems for xEV have been developed on the basis of our proprietary original motor control technology.
2015-04-14
Journal Article
2015-01-0612
Weiguo Zhang, Zeyu Ma, Ankang Jin, James Yang, Yunqing Zhang
Abstract Nowadays, studying the human body response in a seated position has attracted a lot of attention as environmental vibrations are transferred to the human body through floor and seat. This research has constructed a multi-body biodynamic human model with 17 degrees of freedom (DOF), including the backrest support and the interaction between feet and ground. Three types of human biodynamic models are taken into consideration: the first model doesn't include the interaction between the feet and floor, the second considers the feet and floor interaction by using a high stiffness spring, the third one includes the interaction by using a soft spring. Based on the whole vehicle model, the excitation to human body through feet and back can be obtained by ride simulation. The simulation results indicate that the interaction between feet and ground exerts non-negligible effect upon the performance of the whole body vibration by comparing the three cases.
2015-04-14
Technical Paper
2015-01-1644
Huan Li, Ying Huang, Gang Li, Yongguang Yang
Abstract The cylinder-by-cylinder variations have many bad impacts on the engine performance, such as increasing the engine speed fluctuation, enlarging the torsional vibration and noise. To deal with this problem, the impact mechanism of cylinder-by-cylinder variations on low order torsional vibration has been studied in this paper, and subsequently a new individual cylinder control strategy was designed by processing the instantaneous crankshaft rotation speed signal, detecting the cylinder-by-cylinder variation and using feed-back control. The acceleration characteristics of each cylinder in each engine cycle were compared with each other to extract the variation index. The feed-back control algorithm was based on the regulation of the fuel injection according to the detected variation level.
2015-04-14
Technical Paper
2015-01-1558
Amir Kharazi, Edward Duell, Austin Kimbrell, Ann Boh
Abstract Unsteady flow over automotive side-view mirrors may cause flow-induced vibrations of the mirror assembly which can result in blurred rear-view images, adversely affecting marketability through customer comfort and quality perception. Prior research has identified two mechanisms by which aerodynamically induced vibrations are introduced in the mirror. The first mechanism is unsteady pressure loading on the mirror face due to the unsteady wake, causing direct vibration of the mirror glass. The second mechanism, and the focus of this study, is a fluctuating loading on the mirror housing caused by an unsteady separation zone on the outer portion of the housing. A time-dependent Computational Fluid Dynamics (CFD) methodology was developed to correctly model mirror wake behavior, and thereby predict flow-induced mirror vibration to improve performance estimations.
2015-04-14
Technical Paper
2015-01-1504
WeiNing Bao
A ball screw regenerative shock absorber was designed for the relief of the vehicle vibration and the energy recovery of the vehicle vibration. The effect of its main parameters on the suspension system was numerically analyzed. According to the principle of the ball screw regenerative suspension system, a mathematical model of the ball screw regenerative shock absorber was established regarding the ball screw rotational inertia, the motor rotational inertia, the screw lead and the radius of the screw nut. A suspension dynamic model based on the ball screw regenerative shock absorber was developed combining the road model and the two-degrees-of-freedom suspension dynamic model.
2015-04-14
Journal Article
2015-01-1506
Bastian Scheurich, Tilo Koch, Michael Frey, Frank Gauterin
Today, body vibration energy of passenger cars gets dissipated by linear working shock absorbers. A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and to store vibration energy. A gyroscope is set to high speed revolutions by an electric motor and a gimbal is used for bearing. The gimbal consists of an outer ring which is connected to the vertical movement of the wheel carrier. Right-angled to the outer ring, there is an inner ring pivoting the gyroscope right-angled. In order to avoid undesirable body movements, the directional vector of the angular velocity of the gyroscope is parallel to the car’s yaw axis.
2015-04-14
Technical Paper
2015-01-1615
Yuksel Gur, Jian Pan, John Huber, Jeff Wallace
Ford Motor Company and Magna International Inc., co-funded by the U.S. Department of Energy, have collaborated on a lightweight vehicle concept project that uses advanced material solutions to achieve a nearly 25% weight savings over the reference vehicle. Lightweight design actions on radiating panels enclosing the vehicle cabin generate vehicle interior acoustic degradation due to the reduction of panel surface mass. In order to reduce this deficiency, an MMLV vehicle sound package development study was conducted to improve NVH performance of MMLV with industry leading ultra-light weight sound package technologies. Our goal was to improve acoustical performance of MMLV by 2 dB without increasing the total sound package weight of the “Vehicle A” which is the baseline vehicle for MMLV.
2015-04-14
Technical Paper
2015-01-0235
Shiv Shankar Prasad, Jahangir Mansoori, Jin Seo Park
Abstract A vehicle horn is a sound-making device used to warn others of any approaching vehicle or of its presence. Some countries require horns by law. Conventional Horns are electromechanical with steel diaphragm and electromagnet acting upon it. Switching of horn is performed by mechanical contact breaker assembly that repeatedly interrupts the current to electromagnetic. Up-Down movement of diaphragm with response to the current creates a sound wave across horn. Conventional Horn faces the problem of wear and tear of mechanical contact and internal parts. Switching of contacts results in arcing. There is no current and surge voltage protection for the coil of conventional horn. These problems of conventional system might be accepted in the general market, but in specific markets which are using horn frequently; these have to be considered as serious issues. Especially, horns are one of the most abusive parts of vehicle in India.
2015-04-14
Technical Paper
2015-01-0825
Gen Shibata, Koki Ishi, Hirooki Ushijima, Yushi Shibaike, Hideyuki Ogawa, David E. Foster
Abstract Premixed diesel combustion offers the potential of high thermal efficiency and low emissions, however, because the rapid rate of pressure rise and short combustion durations are often associated with low temperature combustion processes, noise is also an issue. The reduction of combustion noise is a technical matter that needs separate attention. Engine noise research has been conducted experimentally with a premixed diesel engine and techniques for engine noise simulation have been developed. The engine employed in the research here is a supercharged, single cylinder DI diesel research engine with a high pressure common rail fuel injection system. In the experiments, the engine was operated at 1600 rpm and 2000 rpm, the engine noise was sampled by two microphones, and the sampled engine noise was averaged and analyzed by an FFT sound analyzer.
2015-04-14
Technical Paper
2015-01-1113
Jae Sung Bang, Young-Kwan Ko, Tae-Hee Jung
Abstract In this paper, we consider the driveline oscillations for electric vehicles. The oscillations in the electric vehicle result from the lack of the damping component such as a torque converter. The oscillations should be suppressed for the ride comfort. The new method is suggested using wheel speeds and the newly designed filter. The method guarantees better performance to eliminate the oscillations and better robustness against disturbances such as a brake force, road slope, and so on. The effectiveness of the suggested method is verified by experimental results.
2015-04-14
Technical Paper
2015-01-1195
Kiyotaka Maeda, Masashi Takahashi
Abstract To verify the appropriateness of the vibration test conditions of ISO 12405, we performed tailoring to derive power spectrum densities and test durations as vibration test conditions. Vehicles used for tailoring included two electric vehicles and one plug-in hybrid electric vehicle. Those vehicles were equipped with accelerometers and were run on seven different road types at different speeds while data on the acceleration of the battery packs were recorded. The power spectrum densities for three axes that were derived from the obtained acceleration data were similar in form to the power spectrum densities of ISO 12405, and almost the same root mean square accelerations were obtained, confirming that they are appropriate. However, both experiments and theory suggest that the test duration for the Z-axis exceeds those of the X- and Y-axes.
2015-04-14
Technical Paper
2015-01-1124
Gerrit Knabe, Markus Zahlten, Ferit Kücükay
In order to improve the acoustic comfort inside passenger cars in terms of transmission noise, a special method has been developed. For a structured and comprehensive analysis of the transmission noise, the generation and transfer mechanisms are divided into four separate but nevertheless connected parts. Although simulation and components tests are used to analyze vibration excitation which may cause rattle and the mechanisms causing rattle in detail, they are not the main part of the analysis. The focus of this study is on the transfer of automotive transmission rattle and the passengers’ perception. The noise characteristics, which can be specified using conventional analysis methods as well as assessments by test persons, are important for the transfer path of the disturbing noise. By combining different methods of transfer path analysis (TPA), direct airborne-sound transmission is identified as a significant transfer path of the rattling noise.
2015-04-14
Technical Paper
2015-01-1555
Charalampos Kounenis, David Sims-Williams, Robert Dominy, Arganthaël Berson, Nicholas Oettle, Claire Freeman
Abstract A vehicle driving on the road experiences unsteady flow conditions which are not generally reproduced in the development environment. This paper investigates the potential importance of this difference to aeroacoustics and hence to occupant perception and proposes a methodology to enable better ranking of designs by taking account of wind noise modulation. Two approaches of reproducing the effects of unsteady wind on aeroacoustics were investigated: an active wind tunnel Turbulence Generation System (TGS) and a quasi-steady approach based on measurements at a series of fixed yaw angles. A number of tools were used to investigate the onset flow and its impacts, including roof-mounted probe, acoustic heads and surface microphones. External noise measurements help to reveal the response of separate exterior noise sources to yaw.
2015-04-14
Technical Paper
2015-01-0212
Mohamed El Morsy, Gabriela Achtenova
Abstract An efficient condition monitoring system provides early warning of faults by predicting them at an early stage. When a localized fault occurs in gears, the vibration signals always exhibit non-stationary behavior. The periodic impulsive feature of the vibration signal appears in the time domain and the corresponding gear mesh frequency (GMF) emerges in the frequency domain. However, one limitation of frequency-domain analysis is its inability to handle non-stationary waveform signals, which are very common when machinery faults occur. Particularly at the early stage of gear failure, the GMF contains very little energy and is often overwhelmed by noise and higher-level macro-structural vibrations. An effective signal processing method would be necessary to remove such corrupting noise and interference. In this paper, a new hybrid method based on optimal Morlet wavelet filter and autocorrelation enhancement is presented.
2015-04-14
Journal Article
2015-01-1206
Manabu Yazaki
Abstract A new motor has been developed that combines the goals of greater compactness, increased power and a quiet drive. This motor is an interior permanent magnet synchronous motor (IPM motor) that combines an interior permanent magnet rotor and a stator with concentrated windings. In addition, development of the motor focused on the slot combination, the shape of the magnetic circuits and the control method all designed to reduce motor noise and vibration. An 8-pole rotor, 12-slot stator combination was employed, and a gradually enlarged air gap configuration was used in the magnetic circuits. The gradually enlarged air gap brings the centers of the rotor and the stator out of alignment, changing the curvature, and continually changing the amount of air gap as the rotor rotates. The use of the gradually enlarged air gap brings torque degradation to a minimum, and significantly reduces torque fluctuation and iron loss of rotor and stator.
2015-04-14
Technical Paper
2015-01-1665
Nicolas Arnault, Adrien Baudet, Nicolas Becker
Vehicle integration in today society and especially in urban zones is the one of the main focus of regulators as well as car manufacturers. Indeed, vehicles impact on everyday life as air quality, noise, traffic density, urban spaces occupied by parked cars, among others is scrutinized and leads to at least significant efforts, but often to major improvements on all those topics. Noise is one of the key nuisances from which the car is the source. There are already some existing regulations, and they intend to become stricter and stricter. The perfect example of this trend is the recent new European Commission regulation adopted in April 2014, which requires a fair reduction of the allowable emitted noise, but may also introduce performance labels. Of course, there are solutions to deal with noise emissions.
2015-04-14
Journal Article
2015-01-1088
Tomohiko Usui, Tomoya Okaji, Tatsuya Muramatsu, Yoshiyuki Yamashita
Abstract By optimizing parameters related to damping performance and adopting a layout that incorporates the turbine into the damper components, a “Turbine Twin-Damper” lock-up damper was developed that achieves both damping performance and compactness. To reduce losses in the fluid flow channel, a smaller torus was developed that reduce the width of the torus by about 30%.Through the combination of this Turbine Twin-Damper and smaller torus, attenuation of the torque fluctuation transmitted to the transmission to 1/2 or less compared to a conventional product was achieved without increasing the overall width of the torque converter. As a result, the engine speed at cruise fell by 400rpm, and fuel economy improved.
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