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NVH benefit of the Frunk

Autoneum Management AG-Federico Di Marco, Flavio Pezzani, Andreas Daving, Luca Mazzarella
  • Technical Paper
  • 2019-01-1456
To be published on 2019-06-05 by SAE International in United States
Due to the increasing number of battery electric vehicles (BEVs), the engineering fields regarding driving comfort and NVH issues are becoming more and more challenging: many new factors affect the development of BEVs NVH package. The noise sources related to the powertrain are different from the traditional ones of internal combustion engines, for instance due to the presence of tonal components, strong harmonics and potential whining noise. To satisfy NVH specifications and the need for lightweight solutions to increase driving range, it is important to mask as much as possible the noise coming from the engine bay with materials both lightweight and acoustically performing. Moreover, for electric vehicles new interesting solutions are possible with the introduction of new components, that do not find room under the hood of ICE or hybrid vehicles. These components, if properly designed, could lead to non-negligible NVH benefits. The present paper reports the NVH effects of one of these new components, the frunk, a small compartment inside the engine bay, functionally similar to the trunk. In this paper, the design-by-simulation…

Structural Vibration and Acoustic Analysis of a 3-Phase AC Induction Motor

Peyman Poozesh
Kettering Univ-Allan Taylor, Javad Baqersad
  • Technical Paper
  • 2019-01-1458
To be published on 2019-06-05 by SAE International in United States
This paper is aimed at studying the NVH and acoustic performance of a 3-phase AC induction motor in order to find a way to reduce the magnetic component of noise from an electric motor in an electric vehicle (EV). The method suggested here is to reduce the magnetic component of sound from the motor by making modifications to the end bracket of the motor housing. EVs are being considered the future of mobility mainly owing to the fact that they are environment-friendly. With a lot of companies already investing heavily in this technology, electric drives are set to become extremely popular in the years to come. The heart of an EV is its motor. Modern electric vehicles are quiet and with the lack of an IC engine to mask most sounds from other components, the sound from the electric motor and other auxiliary parts become more prominent. This paper lays down a process to analyze the sound radiated from the electric motor in three broad steps. First, to model the motor in an electromagnetic platform,…

The Mechanism of Hissing Noise in the Automotive Cabin and Countermeasures for its Reduction

Mitsubishi Motors Corporation-Atsushi Itoh, ZongGuang Wang
  • Technical Paper
  • 2019-01-1474
To be published on 2019-06-05 by SAE International in United States
The popularity of environment friendly products such as electric vehicle (EV) and plug-in hybrid electric vehicle (PHEV) has been increasing. One of the major qualities of those vehicles is the quietness in the cabin with the help of the replacement of the drive power source and improvements of vibration reduction techniques. However, the reduction of the main noise can make the secondary noise like air-conditioning (A/C) noise to highly contribute to the automotive noise. A/C system induces some abnormal noise and its excessive noise level is unpleasant for customers. In this paper, the hissing noise generated from the refrigerant system is taken since it often occurs. In order to understand the mechanism, for the first step, the visualization method to capture the behavior of multi-phased refrigerant flow jet inside the pipe was proposed with high-speed camera, some light devices and acrylic test piece. In addition, image analysis to quantify the flow regime from a series of observed snapshots. Using proposed method, the correlation study between flow and noise was performed at A/C bench test. As…

Augmenting Vehicle Production Audit with Objective Data and Sound Quality Metrics to Improve Customer Satisfaction

Bruel & Kjaer North America Inc.-Brian Thom
Bruel & Kjaer Sound/Vib Meas A/S-Gabriella Cerrato
  • Technical Paper
  • 2019-01-1531
To be published on 2019-06-05 by SAE International in United States
Vehicle manufacturers are facing increasing challenges in auditing the build quality of their vehicles while considering increasing consumer demands. This effect is compounded with the rise in electric and hybrid vehicles. The ability to audit vehicles at the end of line for a variety of noise types is becoming increasingly important; these include engine noise, road noise, wind noise, BSR and electric vehicle specific noises. An automated measurement system was developed with specific algorithms and sound quality metrics to not only audit vehicle production but to add objective data, pass-fail criteria and trend analysis.

An interactive approach for design and development of electric vehicle sounds

Mueller-BBM Active Sound Technology GmbH-Katharina Schmidt, Somasundaram Alagappan, Roman Franke, Moritz Beyreuther, Rolf Schirmacher
  • Technical Paper
  • 2019-01-1568
To be published on 2019-06-05 by SAE International in United States
Though the idea of masking the undesired tonal and intermittent noises arising from local ancillary elements of the powertrain of electric vehicles is clear for many automotive manufactures, the acoustic nature of such masking sound is still under development. Since this masking sound need also to represent their brand sound DNA, it needs to be creatively designed and clinically derived. As the task to bridge the design ideas into real vehicles involves usage of range of processes and extensive toolchains i.e. sound design creation, online parametrization via real tunings till the creation of production ready flash able datasets, this is the major ongoing challenge for automotive manufacturers. Considerably short development time and constraints in involved cost for such elaborative processes makes this task still tighter. In order to overcome this hurdle of challenge involving the realization of multiple iterative processes in parallel to limited time and monetary constraints, the automotive manufacturers need to adopt a flexible and agile way of sound development approach using lean sound prototyping tools. The ability to work from scratch till…

Power Electronic Noise - Simulation Measurement Comparison

AVL LIST GmbH-Markus Resch, Thomas Resch, Stephan Brandl
AVL Software and Functions Gmbh-Peter Olbrich, Hartwig Reindl
  • Technical Paper
  • 2019-01-1451
To be published on 2019-06-05 by SAE International in United States
A growing development of hybrid or fully electrical drives increase demand for accurate prediction of noise and vibration characteristic of electric and electronic components. This paper describes the numerical and experimental investigation of noise emission from power electronics, as a one of the new important noise sources in electric vehicles. Emitted noise from the printed circuit board (PCB) equipped with multi-layer ceramic capacitors (MLCC) is measured and used for calibration and validation of numerical model. Material properties are tuned using results from experimental modal analysis with special attention on orthotropic characteristic of PCB glass-reinforced epoxy laminate sheet (FR-4). Structural vibrations are calculated with commercial FEM solver with modal frequency response analysis. Sound radiation is simulated using the wave based approach. Simulation and experimental results are compared in frequency range up to 10 kHz. Developed simulation methodology can successfully identify the main noise sources from equipped PCB. Critical peak noise responses are identified both in experiment and simulation.

Test and Analysis of Electromagnetic Noise of an Electric Motor in a Pure Electric Car

Geely Automobile Research Institute-Perry Gu, Chao Gong
Geely Automoile Research Institute-Qiang kang
  • Technical Paper
  • 2019-01-1492
To be published on 2019-06-05 by SAE International in United States
Compared with the low-frequency ignition order of mechanical and combustion noise of the internal combustion engine, the electric drive assembly noise of electric vehicles is mainly the high-frequency whining order noise generated by the electromagnetic force and gear meshing, as well as the high-frequency umbrella noise generated by DC/AC pulse width modulation. Although the radiated sound power is far less than that of an internal combustion engine, the high frequency noise of the motor and the reducer is also annoying. In this paper, the main characteristics of the vibration and noise of an electric motor are obtained by testing it on the vehicle and on the test rig. The main frequency orders are multiplies of motor poles, of which the most significant is the 48th order. The deformation of the motor at the resonance frequency of the 48th order is the breathing mode. Through analysis of electromagnetic force wave, the sources of main orders of motor noise are explained. The most significant order 48th comes from the interaction between rotor magnetic field and stator slots.…

Tonal Annoyance Metric Development for Automotive Electric Vehicles

General Motors-Glenn Pietila, William Seldon, Timothy Roggenkamp, Timothy Bohn
  • Technical Paper
  • 2019-01-1467
To be published on 2019-06-05 by SAE International in United States
Historical metrics intended to drive the development of vehicle powertrains have focused on sounds that are characteristic of IC engines. The interior noise contribution of the propulsion system in electric vehicles has significantly more tonal noise than their IC engine counterparts. This tonal noise is not adequately represented by current propulsion systems metrics. While metrics exist today that were developed to represent the presence of tones in sounds most have focused on the level aspect of the tones relative to the surrounding noise or masking level, some examples include tonality, tone-to-noise ratio, and prominence ratio. A secondary, but also important aspect of tones is the annoyance as a function of frequency. This paper will highlight the development of a tonal annoyance weighting curve that can be used to account for the frequency aspect of tonal annoyance relative to electric vehicles. This weighting curve can then be used in conjunction with the current tonal metrics to represent perceived tonal annoyance of electric vehicles. The benefit of the tonal annoyance weighting curve is demonstrated by comparing tonal…

Effects of the Feature Extraction from Road Surface Image for Road Induced Noise Prediction using Artificial Intelligence

Gifu University-Yuichi Matsumura, Kojiro Matsushita
Toyota Motor Corp.-Shunsuke Nakamura, Masashi Komada, Keisuke ishizaki
  • Technical Paper
  • 2019-01-1565
To be published on 2019-06-05 by SAE International in United States
Next-generation vehicles driven by motor such as electric vehicles and fuel cell vehicles have no engine noise, so the balance of interior noise is different from the vehicles driven by conventional combustion engine. In particular, road induced noise tends to be conspicuous in the low to middle vehicle speed range, therefore, technological development to reduce it is important task. The purpose of this research is to estimate the frequency of the peak level of road induced noise from the signals of sensors adopted for automatic driving without newly adding sensors for utilizing the estimation result as a reference signal to reduce road induced noise by active control or semi active control. Using the monocular camera which is the simplest image sensor, the peak frequency of the road induced noise is estimated from the road surface image ahead of the vehicle by machine learning. The feature quantities are extracted using three image recognition techniques (HOG, CNN, autoencoder) from the pixel data of road surface images. From the feature quantities obtained by the above method, the frequency…

The new challenges of NVH packages for BEVs

Davide Caprioli, Jan Horak
Autoneum Holding AG-Grégoire Lepoittevin
  • Technical Paper
  • 2019-01-1452
To be published on 2019-06-05 by SAE International in United States
Battery electric vehicles (BEVs) bring new challenge when it comes to develop their NVH package, which is affected by many new factors. The noise sources from the powertrain are different, for instance due to the presence of tonal components, strong harmonics and potential whining noise. Another important aspect is the missing effect of masking noise from a combustion engine. As a consequence, other noise sources, such as tires, become more predominant. This means that the NVH package has to be re-engineered considering the new noise sources ranking and cannot just be significantly decontented in general. In addition, the NVH package should at least partly counterbalance the vehicle weight increase due to the presence of a large and heavy battery pack in order to maximize the driving range. In the early days of BEVs, OEMs mostly carried over technologies used on combustion engine vehicles to electric cars. With the development growth of specific vehicle platforms for electric cars, NVH strategies and technologies might strongly change. First, this paper aims at providing a benchmarking review of current…