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2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-03-28
Technical Paper
2017-01-1050
George Nerubenko, Cyril Nerubenko
The study of dynamical performance and effectiveness of new proposed system of vibration dampers for any type of propulsion (Electric Motor Cars, Hybrid Vehicles and Petrol Engine Automobiles) is presented. Design and structure of proposed system is based on George Nerubenko US Patents 7,438,165 and 7,464,800 having the control system with self-tuning contour adjusted for all operational frequencies in running propulsion. The proposed system of vibration damper configurations having the simplest mechanical variable damping devices is observed. The proposed system of vibration dampers consists of combination of patented Bending / Torsional Vibration Dampers and Flywheels. The developed schemes would be applied for a design of all kinds of powertrains, transmissions, and drivelines successfully replacing the conventional vibration reduction tools.
2017-03-28
Technical Paper
2017-01-1072
Jelena Andric
Variable valve actuation (VVA) plays a promising role in supporting advanced combustion methods to meet increasingly stringent fuel efficiency and emission standards in modern vehicles. Much research has been done on VVA to exploit its potential for increasing the overall engine performance. Consequently, the use of VVA in internal combustion engines (ICE) has become more prevalent in recent past. Different flexible VVA technologies have been designed and manufactured to make it possible to control valve events and valve timing over the entire operating range of an engine. Therefore, it is of high interest to comprehensively understand the benefits of numerous VVA mechanisms that can be used to ensure the flexibility of the valve train system. Variable valve timing (VVT) technologies include early or late opening or closing time of the intake or exhaust valves. VVA combine any method of valve timing with variable lift, phase, and duration.
2017-03-28
Technical Paper
2017-01-1063
Tonghang Zhao, Xining Liu, Meng Yang, Yulei He, Hangsheng Hou
In contrast with conventional ICE vehicles, hybrid electric vehicles have their unique power flow structure and operating conditions, which complicates HEV’s NVH performance and design. At present, the HEV programs are mostly carried over from their corresponding conventional counterparts for many OEM’s. As a result, the total vehicle weight will increase 10% to 15% compared to their conventional version. However, the vehicle structural characteristics, such as hard points and chassis suspension stiffness, still remains similar to their conventional version. Therefore, even under the same operating conditions, HEV’s might develop more serious and complicated NVH problems. In this work, the structural and operating characteristics of an HEV is briefly explained first. Based on the principle of vibration and noise control methodology, the most effective NVH control strategies under typical HEV operating conditions are looked into and presented.
2017-03-28
Technical Paper
2017-01-0440
Jun Lu, Zhenfei Zhan, Haozhan Song, Xu Liu, Xin Yang, Junqi Yang
Noise-vibration-harshness (NVH) design optimization problems have become major concerns in engineering design phase. For complex vehicle body structures, the numerous design variables and constraints make the direct optimization design inefficient needing enormous iterations. In this work, to reduce computational burden, the screening analysis is firstly performed to detect the most important variables prior to the design optimization. Then the response surface approximate method coupled with design of experiment (DOE) technique is employed to replace time-consuming finite element vibration analysis. Subsequently, an optimization of NVH performance considering dynamic response is formulated and solved using the adaptive simulated annealing (ASA) algorithm. The methodology aims at improving the NVH behavior of body structure by simultaneously suppressing several resonance peaks in frequency domain.
2017-03-28
Technical Paper
2017-01-1125
Victor Baumhardt, Valdinei Sczibor
Halfshafts are very important components from vehicle powertrain. They are the element responsible to transmit torque and rotation from transmission to wheels. Its most basic design consist of a solid bar with joints at each extreme, however, Depending of its length, the natural frequency of first bending mode might have a modal alignment with engine second order, resulting in undesired noise on vehicle interior. Many design alternatives are available to overpass this particular situation, like adding dampers, use tube shafts or use link-shafts, however, all of them are cost affected. The aim of this study is to propose an optimal halfshaft profile for a solid shaft to be machined from a rough bar, pursuing the lowest frequency the possible for the first bending mode by changing its diameter and, as a consequence, the mass and bending stiffness at appropriate regions.
2017-03-28
Technical Paper
2017-01-1121
Deb Bonnerjee, Djamel Bouzit, Javed Iqbal
Ting noise has a significant contribution to the driver’s perceivable transient NVH during acceleration from a stop or while driving. This metallic noise can be present in vehicles with any variant of the driveline architecture (FWD, AWD, RWD and 4X4). This paper details the generation mechanism of the noise excitation and defines the physical and design parameters that influence it. This paper will focus on the noise generated between halfshaft to wheel hub interface. Same phenomena apply to all other torque transferring components that use axial splines assembled with specified nut torque. Bench tests were conducted measuring the transient noise generated when powertrain torque is applied to the halfshaft which moves relative to wheel hub after overcoming the frictional torque. The properties of two interfacing surfaces (halfshaft joint tulip and wheel hub) are studied; including coefficient of friction and design features.
2017-03-28
Technical Paper
2017-01-1122
Yashodhan V. Joshi
Vehicle noise has reduced over the years due to the customer demand for quieter vehicles. As engines have become quieter by efforts to reduce the combustion noise, as well as, by moving away from mechanical fuel pumps to common rail fuel pumps, the geartrain noise has come under increased scrutiny. Gear whine could be a result of multiple factors, and gear profile distortion is one of those factors. ISO 10064 provides guidance on the distortion due to temperature effects, but does not describe other influences in detail. There is not much published literature about gear whine due to profile distortion. The work attempts to fill that gap by describing a gear whine problem due to profile distortion and load change and it’s resolution by changing the gear design.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu
Aiming at the variable displacement oil pump, the modal and noise were studied, and structural optimization and test verification were carried out. The modal analysis of the variable displacement oil pump was carried out by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. Sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment. The modal of the variable displacement oil pump was analyzed by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. The sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment.
2017-03-28
Technical Paper
2017-01-0449
Yinzhi He, Bin Wang, Zhe Shen, Zhigang Yang, Gunnar Heilmann, Tao Zhang, Guoxu Dong
Beamforming technique is today widely used in aeroacoustic wind tunnel to identify wind noise sources generated by interaction between incoming flow and test object. In this study, a planar spiral microphone array with 120 channels was set out-of –flow of 1:1 aeroacoustic wind tunnel of Shanghai Automotive Wind Tunnel Center (SAWTC) to test exterior noise sources of a production car. Simultaneously, 2 reference microphones were set in vehicle interior to record potential sound source signals synchronously and a spherical array with 48 channels inside the vehicle to identify interior noise sources. With different correlation methods and some advanced algorithms, i.e. using CSM and Clean-Sc, the ranking of contributions of vehicle exterior wind noise sources to interested interior noise locations was accomplished. Hereby, Correlation analysis results of interior and exterior noise sources using virtual and real reference microphones are compared and discussed.
2017-03-28
Technical Paper
2017-01-0448
Prakash T. Thawani, Stephen Sinadinos, John zvonek
Prakash Thawani, Steve Sinadinos and John Zvonek DENSO International America Inc. Southfield, MI Abstract With the advent of EVs/HEVs and implementation of Idle-Stop-Start (ISS) technologies on internal combustion engine driven cars/trucks to improve fuel economy and reduce pollution, refrigerant sub-system (RSS) induced noise phenomena like, hissing, gurgling and tones become readily audible and can result in to Customer complaints and concerns. One of the key components that induces these noise phenomena is the Thermal Expansion Valve (TXV). The TXV throttles compressed refrigerant through the evaporator that results in air-conditioning (A/C) or thermal system comfort and defogging when needed. Under certain operating conditions, the flow of gas and/or liquid/gas refrigerant at high pressure and velocity excites audible acoustical and structural modes inherent in the tubing/evaporator/HVAC case.
2017-03-28
Technical Paper
2017-01-0442
Harchetan Singh Aneja, Manas Tripathi, Harmeet Singh, Aashish Parmar
With increase in customer expectations for a quiet and comfortable ride, it has become the need of the hour for automobile manufacturers to continuously improve automobile powertrain NVH. Today's customer has become so aware of vehicle related noises that in-tank fuel pump noise is no exception to this checklist of evaluating cabin NVH. In-tank Fuel pump, that is responsible for delivering the fuel from fuel storage tank to delivery rail, uses an electric motor driven component. The rotating parts (rotor, etc.) produce vibrations that may traverse to tank body & subsequently the vehicle body. Since noise is essentially an audible vibration at its root, these structure borne vibrations may be perceived as noise inside passenger cabin. Additionally, noise may also be produced by fuel flow pulsations if transferred through the piping to the vehicle body. This paper focuses on various approaches to reduce the fuel pump generated noise heard inside passenger cabin.
2017-03-28
Technical Paper
2017-01-0444
Weiguo Zhang, Mark Likich, Brian Butler, John White
Engine air induction shell noise is a structure borne noise that radiates from the surface of the air induction system. The noise is driven by pulsating engine induction air and is perceived as annoying by vehicle passengers. The problem is aggravated by vehicle design demands for low weight components packaged in an increasingly tight under hood environment. Shell noise problems are often not discovered until production intent parts are available and tested on the vehicle. Part changes are often necessary which threatens program timing. Shell noise can negate air induction NVH development by overriding acoustic abatement features such as Helmholtz resonators and large air boxes. Shell noise should be analyzed in the air induction system design phase and a good shell noise analytical process and targets must be defined. A numerical analytical process is developed to predict the radiated sound power of air induction components.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Due to regulations related to global warming, the auto industry is transitioning to the use of a new refrigerant R1234yf in many markets/regions. This transition to the new refrigerant was considered to be a minor development effort with main focus on improved sealing, improving cooling capacity with adding content such as Internal Heat Exchanger (IHX) to recoup the lower cooling efficiency of R1234yf compared to R134a. There were no redesigns of major refrigerant system components expected with the introduction of R1234yf. The actual implementation of this refrigerant has proven to be more challenging due to several NVH issues. Some of the challenges related to NVH are driven by the differences in refrigerant characteristics – mass flow rate, velocity of sound in refrigerant.
2017-03-28
Technical Paper
2017-01-0445
Muthukumar Arunachalam, Arunkumar S, PraveenKumar Sampath, Abdul Haiyum
In recent years, there is increasing demand for every CAE engineer on their confidence level of the virtual simulation results due to the upfront robust design requirement during early stage of an automotive product development. Apart from vehicle feel factor NVH characteristics, there are certain vibration target requirements at system or component level which need to be addressed during design stage itself in order to achieve the desired functioning during vehicle operating conditions. Vehicle passive safety system is one of which primarily consists of acceleration sensors, control module and air-bag deployment system. As the sensors act as the front-end of passive safety system and control module’s decision is based on these sensors signals, its mounting locations should meet the sufficient inertance or dynamic stiffness performance in order to avoid distortion in signals due to its structural resonances.
2017-03-28
Technical Paper
2017-01-1330
Youssef Ziada, Juhchin Yang, David DeGroat-Ives
Due to decreased development cycle timing, designing components for manufacturability has never been as important. Assessing manufacturing feasibility has therefore become an increasingly important part of new product engineering. This manufacturing feasibility is conventionally assessed based on static stiffness of components and fixture assemblies. However, in many operations, excess vibration represents the actual limitation on processing a workpiece. Limits on how far into components a tool can reach or the amount of processing time required to machine a feature is commonly decreased significantly due to vibration. Significant time is spent resolving these vibration problems during product launches. Depending on the machining configurations these vibrations can be due to the part & work support structure or due to the tooling & spindle assembly. This paper presents approaches for predicting the dynamic flexibility for either of these assemblies using purely analytical approaches.
2017-03-28
Technical Paper
2017-01-0405
Tianqi Lv, Xingxing Feng, Peijun Xu, Yunqing Zhang
Several constitutive models which capture the amplitude and frequency dependency of filled elastomers are implemented for the conventional engine mounts of automotive powertrain mounting system (PMS). Firstly, a multibody dynamic model of a light duty truck is proposed, which includes 6 degrees of freedom (DOFs) for the PMS. Secondly, several constitutive models for filled elastomers are implemented for the engine mounts of the PMS, including nonlinear elastic model, frictional derivative viscoelastic model, general Maxwell chains, Coulomb-type friction, Berg’s friction model, common Kelvin-Voigt model etc. The nonlinear behavior of dynamic stiffness and damping of the mounts are investigated. Thirdly, simulations of engine vibration dynamics are presented and compared with these models and the difference between common Kelvin-Voigt model and other constitutive models are observed and analyzed.
2017-03-28
Technical Paper
2017-01-0333
Kurt Munson, Frederic Kihm, Andrew Halfpenny
Finite Element Analysis (FEA)-based structural simulations are typically used to assess the durability of automotive components. Many parts experience vibration in use, and resonance effects are directly linked to many structural problems. In this case, dynamics must be included in the structural analysis. Dynamic FEA can be more realistic than static analysis, but it requires knowledge of additional characteristics such as mass and damping. Damping is an important property when performing dynamic FEA, whether transient or steady state frequency response, as it governs the magnitude of the dynamic stress response and hence durability. Unfortunately the importance of damping is often overlooked; sometimes a default damping value is erroneously assumed for all modes. Errors in damping lead to errors in the stress response, which in turn lead to significant changes in the fatigue life estimates.
2017-03-28
Technical Paper
2017-01-0403
Guangqiang Wu, Huwei WU
Experimental program and considerations, frequency characteristics, subjective and objective sound quality evaluation and prediction model establishment of a certain mass-production SUV (Sport Utility Vehicle, SUV) manual transmission gear rattle phenomenon were analyzed in this paper. Firstly, vehicle experiment schemes, including experimental operating conditions, vibration acceleration sensor and microphone arrangements and especial considerations in experiments, were introduced in detail. Secondly, through coherence analysis in frequency domain and time-frequency analysis in time-frequency domain, broadband characteristics of manual transmission gear rattle vibro-impact and frequency range of 350~4500Hz were concluded on vehicle idling condition and creeping condition.
2017-03-28
Technical Paper
2017-01-1051
Hassan nehme, Abdelkrim Zouani
Turbocharged engines constitute one of the strategies used by Ford Motor Company to deliver engines with improved fuel economy and performance. However, turbochargers exhibit many inherent NVH challenges that need to be addressed in order to deliver refined engines that meet customers’ expectations. One of these challenges is the turbocharger 1st order synchronous noise due to the interaction between the manufacturing tolerances of the rotating components and the dynamics of the rotor. This paper presents an analytical method to compute the turbocharger bearing forces and predict the 1st order synchronous noise and vibrations. The method consists of a fully coupled turbocharger rotor dynamic analysis in a flexible turbocharger housing structure; it predicts housing vibrations under various manufacturing tolerance conditions. The predicted vibrations of the turbocharger housing are compared to measured test data to demonstrate the validity of the analytical method.
2017-03-28
Technical Paper
2017-01-1055
Baolin Yu, Zhi fu, T Bin Juang
The automotive industry is experiencing a profound change due to increasing pressure from environmental and energy concerns. This leads many auto makers to accelerate hybrid and electric vehicle development. Generally smaller engines utilized by hybrid and electric vehicles lend themselves to quieter operation. However, customer satisfaction could be negatively impacted by the peak whine emitted by electric motor. Unlike conventional gas vehicles, the strategy for reducing motor whine is still largely unexplored. This paper presents an analytical study on electric motor whine radiated from a hybrid vehicle transmission. The analysis includes two stages. Firstly a detailed finite element (FE) model of transmission is constructed, and case surface velocities are calculated utilizing electromagnetic force. Then a boundary element model is built for evaluating noise radiated from the transmission surface using acoustic transfer vector (ATV) method.
2017-03-28
Technical Paper
2017-01-1056
Rong Guo, Xiao-kang Wei, Jun Gao
Commercial demands of comfort and stringent fuel economy have encouraged manufacturers to accommodate advanced technologies such as the Variable Displacement Engine (VDE), downsizing and so on in the new automotive models. Particularly, Active control engine mounts (ACMs) notably contribute to ensuring superior effectiveness in vibration suppression. This paper incorporates a PID controller into the active control engine mount system for inhabiting the transmitted force to the body. Furthermore, integrated time absolute error (ITAE) of the transmitted force is introduced to serve as the control goal for searching better PID parameters. Then the particle swarm optimization (PSO) algorithm is adopted for the first time to optimize the PID parameters in the ACM system. In the end, simulation results are presented for searching optimal PID parameters and validating the performance of the optimized PID control method.
2017-03-28
Technical Paper
2017-01-1058
L V Pavan kumar Maddula, Ibrahim Awara
Increased focus on Fuel efficiency and vehicle emissions has led the automotive industry to look into low weight alternative designs for power train system components. These new design changes pose challenges to vehicle attributes like NVH, durability, etc. Further, the requirement of high power applications produces further complexities. The present work explains how a potential design change of drive shafts driven by a desire to reduce weight and cost can lead to NVH problems caused by drive shaft resonances and explains how using multiple dynamic vibration absorbers(DVA) could solve those issues to meet customer expectation while improving efficiency. This work-stream also highlights the possibility and implications of combining multiple dampers in to a single lower weight vibration absorber.
2017-03-28
Technical Paper
2017-01-1059
Rong Guo, Jun Gao, Xiao-kang Wei
The active engine mount (AEM) is developed in automotive industry to improve overall NVH performance. The AEM is designed to reduce major order of engine vibration over a broad frequency range, therefore it is of vital importance to extract major order signals from vibration before the actuator of the AEM works. This paper focuses on a method of real-time extraction of the major order acceleration signals at the passive side of the AEM. Firstly, the transient engine speed is tracked and calculated, from which the FFT method with a constant sampling rate is used to identify the time-related frequencies as the frequency base. Then the major order signals in frequency domain are computed according to the certain multiple relation of the frequency base. After that, the major order signals of acceleration can be reconstructed in time-domain, which are proved accurate through offline simulation, compared with the given signal.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya marri, Simon Antonov
In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to reduce friction and deliver stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during a complete shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise different porting geometries and vane spacing are used. This paper presents an optimization method intended to identify the best possible spacing for the conventional 7-vanes and 9-vanes oil pumps. The method integrates a Matlab based oil pressure trace model into Mode Frontier computation platform. Bench tests are performed on several pumps with different vane spacing to measure the harmonics of the pressure ripples at the pump outlet in order to validate the results of the optimization study.
2017-03-28
Technical Paper
2017-01-1061
Jiachen Zhai, Lu Cao
Electric vehicle driving permanent magnet synchronous motor has a wide speed range and load changes, with abundant harmonic currents, and its eccentric form is complex, which all result in poor sound quality and abnormal noise problems becoming increasingly prominent. To make a systematic and thorough study of the centralized drive permanent magnet synchronous motor (PMSM) is significant to ameliorate the sound quality and solve noise problems. MATLAB-based modeling technology, SPSS software, and the establishment of sound quality evaluation model for the centralized drive PMSM has a crucial reference value on the research and development of the electric vehicle driving permanent magnet synchronous motor. As for the sound quality of centralized drive PMSM, firstly, in order to get objective parameter values, evaluation models of objective parameters based on psychological acoustics should be established after the collection of the sound samples.
2017-03-28
Technical Paper
2017-01-0420
Prashant Khapane, Sumiran Lohani
Vibration Isolation is the key objective of engine mounting systems in the automotive industry. A well-designed, robust engine mount must be capable of isolating the engine assembly from road-based excitations. The durability of engine mounts is a concern due to their susceptibility to wear and failure owing to high vibrational inputs. A design validation methodology has been developed at Jaguar Land Rover using Multibody Dynamics (MBD) to enhance the prognosis of engine mount loads during full - vehicle durability test events. This paper describes the development of a virtual multi-axial simulation table rig (MAST Rig) to test engine mount designs. For the particular example considered here, a simple sinusoidal input is applied to the MAST Rig. The development of the virtual MAST Rig has been described including details of the modelling methodology.
2017-03-28
Technical Paper
2017-01-1136
Jack S.P. Liu, Natalie Remisoski, Javed Iqbal, Robert Egenolf
Automotive vehicles equipped with Cardan joints may experience a low frequency vehicle launch shudder vibration (5-30Hz) and a high frequency driveline moan vibration (80-200Hz) under operated angles and speeds. The Cardan joint introduces a 2nd order driveshaft speed variation and a 4th order joint articulation torque (JAT) causing the vehicle shudder and moan NVH issues. Research on the Cardan joint induced low frequency vehicle shudder using MBS method has been attempted. A comprehensive MBS method to predict the Cardan joint induced high frequency driveline moan vibration is yet to be developed. This paper presents a hybrid Multi-Body System (MBS) and FEA approach to predict the Cardan joint induced high frequency driveshaft moan vibration. The CAE method considers the elastically coupled driveshaft bending and engine block vibration due to Cardan joint excitation. Detailed driveshaft, joints, slip mechanism, differential, axle and wheel were modeled using a MBS modeling tool.
2017-03-28
Technical Paper
2017-01-1231
Chun Tang, Natee Limsuwan, Nurani Chandrasekhar, Zhichun Ma, Jacob Krizan, Joel Hetrick PhD, Wei Wu
Abstract: Machine three phase current driven by PWM switching inverter in PM machine drive is not ideal sinusoidal, containing different levels of harmonics. The current harmonics have important impact on the electrical machine torque ripple which could translate into transmission and vehicle level noise vibration and harshness (NVH). In this work, the current waveforms were measured from dyno test at prescribed torque and speed levels, and the electric machine torque ripple was computed with the measured current. This paper will focus on the investigation of the current harmonics behaviors and features at various torque and speed conditions, the impact on torque ripple, and the possible mitigation method to reduce torque ripple.
2017-03-28
Technical Paper
2017-01-1226
Nurani Chandrasekhar, Chun Tang, Natee Limsuwan, Jacob Krizan, Zhichun Ma, Joel Hetrick PhD, Wei Wu
Noise and Vibration signature of an electric machine is an outcome of complex interaction between various source level disturbances like torque ripple and radial magnetic force and the surrounding structure to which the motor is attached. These can be radiated directly from the motor housing and also can be transmitted through the structural attachments (stator bolts, mounts etc.). The stator excitation current is not perfectly sinusoidal but contains different levels of harmonics. Harmonics impact Torque ripple, which in turn could translate into undesirable Motor noise. This paper addresses the impact of torque ripple on Motor whine noise. In this work, the electric machine torque ripple was computed based on the stator current that was measured during Motor dyno testing at prescribed torque and speed levels. The Motor NVH under specific torque levels was measured through testing in an anechoic transmission dynamometer cell.
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