Position Paper Noise, Vibration & Harshness - EARPA


Position Paper Noise, Vibration & Harshness - EARPA

European Automotive Research Partners Association aisbl

36-38 Rue Joseph II B-1000 Brussels, Belgium





15 September 2012



Founded in 2002, EARPA is the association of European automotive research organisations. It brings

together the most prominent independent R&D providers in the automotive sector throughout Europe. At

present, EARPA counts 39 members ranging from large and small commercial organisations to national

institutes and universities.

The Task Force NVH was formed in 2005 in order to contribute actively to the European research in road

transport NVH for shaping the sound of tomorrow’s on-road mobility. Thus, the main goals of the Task

Force NVH are

to emphasize the importance of NVH research in road transport, especially in view of CO 2

discussions, light weight design and electrification,

to identify technology needs and research gaps yielding input to future R&D programmes,

to develop and foster cooperation and innovative projects in the field of road transport NVH.

Eighteen members of EARPA form this task force 1 , with expertise in all major fields of automotive NVH

research integrating the key elements of the road transport system – the vehicle, the infrastructure and

the user.

This position paper presents an overall synthesis of the task force members’ view: the relevance of

research and technological development (RTD) on NVH of automotive vehicles, the definition of related

boundary conditions and RTD suggestions for the Horizon2020 Programme of the European Union. From

the independent research providers’ perspective, four major research areas were identified:

new and advanced noise and vibration reduction technologies for propulsion systems and vehicles

with low/zero CO 2 emission

research in specific NVH behaviour of electrified vehicles, particularly for urban transport

specific research in tyre-road noise generation and propagation with focus on electric vehicles, heavy

duty vehicles and urban transport

new and advanced NVH analysis tools as driving factors for enhanced sustainability of road transport

and increased competitiveness of vehicle design within the European Union


Noise, vibration and harshness (NVH) as a field of vehicle technology has two different scopes: firstly,

interior NVH aspects which include the improvement of the interior vibro-acoustic environment for the

drivers and passengers and the protection against occupational health issues for the professional vehicle

driver and, secondly, exterior NVH aspects aiming at the control and reduction of environmental noise

emission by road vehicles (in particular urban areas) but aiming also at a sufficient acoustic noticeability of

electric vehicles (EV) at low speeds for the safety of vulnerable road users.


Members of EARPA TF NVH:

AIT, AVL, CIDAUT, FEV, FhG-LBF, Hexagon, IDIADA, IKA, KU Leuven, LMS, Ricardo, SP,



European Automotive Research Partners Association aisbl

36-38 Rue Joseph II B-1000 Brussels, Belgium


The objectives within the first scope are determined by market needs and have achieved great progress

over the last twenty years. In view of the new challenges of CO 2 reduction with the future propulsion

systems, it is important to maintain and furthermore enhance the current comfort levels under the new

boundary conditions imposed by the alternative drives in order to ensure the competitiveness of the

European automotive industry.

The second scope is mostly determined by the social concern about environmental issues. Environmental

noise emission is an attribute of the vehicle that cannot be assessed by the vehicle driver. However, it is an

essential matter of public interest and is therefore governed not by market needs, but by governmental

and EU regulations.

Over the last ten years noise impact from road vehicles has been a point of special interest in the field of

the environmental effects of road transport. According to the communication “Greening Transport” 2

32 % of the EU population is affected by noise and at least one million healthy life years are lost every

year from traffic related noise in the western part of Europe 3 . Important counteracting initiatives were

taken over the last ten years:

Directive 2002/49/EC on the assessment and management of environmental noise

Amendments to the Directive 70/157/EEC on the permissible sound level of motor vehicles

Amendment to the Directive 97/24/EC relating to the components and characteristics of two- and

three-wheeled motor vehicles

Proposal for a regulation concerning type approval requirements for the general safety of motor

vehicles (including tyre-road noise emission) [COM (2008) 316]

Within the consecutive EU Framework programmes many research projects aimed at development

of noise reducing technologies and noise assessment methods for road transportation noise were


RATIN), as well as the CALM I and II network activities for the exchange of information and

development of noise abatement strategies

Despite all these actions and initiatives the growth of the traffic density and of the number of vehicles in

use will continue. Therefore the total noise impact from road traffic is expected to rise further in the

coming years. Noise emissions per vehicle in each vehicle class have decreased slightly as a result of type

approval regulations and EU framework research efforts, but trends towards heavier vehicles and

developments in vehicle technology (e.g. wider passenger car tyres) have more or less neutralised the

effect of the noise emission reductions on a fleet average level.

Further development of low noise and vibration technology in vehicle design and construction will be

needed to achieve a significant reduction of the noise emission per vehicle, and therefore of the total noise

impact of road transport. In recent years the attention for noise as an environmental issue seems to have

shifted towards the problem of climate change and the related ambition to reduce the energy consumption

of road vehicles. New developments in vehicle technology emerge: reduction of vehicle weight by the use

of lightweight materials, downsizing of engines and the accelerated introduction of hybrid and electric

vehicles. These trends will have definite influences, both positive and negative, on the NVH characteristics

of vehicles. Therefore continuous research efforts will be needed, aiming at

an improved understanding of the relations between vehicle design, driving patterns and noise

emission and the development of measures to further control and reduce the noise emission,

ensuring a good vibro-acoustic interior environment,

and, in striving towards the above, constantly aiming at strengthening the competitiveness of the

European automotive industry.



SEC(2208) 2206: Commission Staff Working Document on Greening Transport, Brussels, 8.7.2008.

WHO (2011): Burden of disease from environmental noise - Quantification of healthy life years lost in Europe


European Automotive Research Partners Association aisbl

36-38 Rue Joseph II B-1000 Brussels, Belgium



Due to the high environmental impacts of transport such as CO 2 emission, local air and noise pollution and

consumption of fossil energy resources, the activities for achieving green and sustainable transport have

high priority 4 and need to be supported by further advanced and new technologies. Thus, research for

reducing transport noise also has to consider all the interdisciplinary aspects of greening the European

transport and its consequences. In addition, it must take into account the economic and market situation.

In EARPA’s view, the primary boundary conditions for research and technological development (RTD) in

road transport NVH are:

compatibility with emission reducing and energy saving technologies (e.g. low friction, light weight

design, downsizing of engines)

consideration of alternative propulsion systems (e.g. hybrids, electrification, range extenders, fuel


safety aspects (e.g. electric vehicles too quiet for pedestrians, wet grip of low-noise tyres,

low/uncommon system feedback to drivers, crashworthiness of batteries)

cost competitiveness (e.g. in comparison with conventional power trains and vehicles)

new mobility requirements (e.g. multi-mode transportation, restricted traffic access to centres of


ecologically friendly and sustainable technologies (e.g. the use of natural light weight materials,



Greening the European transport system requires vehicle manufacturers to adapt the way of developing

vehicles. Power train and transmission systems are in a fundamental change (electrification, hybrid etc.),

and vehicles and engines must be scaled down to reduce weight, cost and fuel consumption. At the same

time, the current high levels of other vehicle attributes such as safety, NVH and reliability have to be at

least maintained. In addition, quality and efficiency of development and production must be improved, to

achieve vehicles that are not only clean, safe and reliable, but also competitive in the end.

This necessitates adaptations and supplements in the research needs of previous research agendas 5,6

leading to updated or new research papers 7,8 .

Under consideration of the primary boundary conditions as described above, the EARPA NVH Task Force

sees the following four major fields of NVH research needs:

A. New and advanced noise and vibration reduction technologies for propulsion systems and

vehicles with low/zero CO 2 emission

‣ Low noise technologies for light weight design of both propulsion systems and vehicle structures

‣ Development/adaptation of novel acoustic materials (such as high damping materials, metal or other

structural foams, meta-materials etc.)

‣ Development of smart systems for improved NVH behaviour (e.g. piezo-electric actuators for active

vibration/noise cancellation) and their integration into the vehicle

‣ Technologies to deal with NVH aspects of engine downsizing and cylinder deactivation strategies






COM(2008) 433 final: Greening Transport, Brussels, 8.7.2008

ERTRAC Strategic Research Agenda Overview, Oct. 2004 (www.ertrac.org)

CALM Strategy Paper: Research for a Quieter Europe in 2020, Sep. 2007

ERTRAC Strategic Research Agenda 2010, Executive Summary and Technical Document, Oct. 2010 (www.ertrac.org)

EARPA General Position Paper 2010: A Vision for Integrated Road Transport Research, Nov. 2010 (www.earpa.eu)


European Automotive Research Partners Association aisbl

36-38 Rue Joseph II B-1000 Brussels, Belgium


B. Research in specific NVH behaviour of electrified vehicles particularly for urban transport

‣ Investigation of the noise behaviour of vehicles with electrified propulsion systems and identification of

the related NVH requirements and achievable targets including sound quality aspects and customers

noise perceptions/expectations, brand identity and competitiveness

Noise reduction technologies for NVH critical elements of electrified propulsion systems such as electric

motor, electric converters, range extender unit, cooling system, air supply and compressor of fuel cells

Noise performance and reduction technologies of electrical auxiliary aggregates and units of hybrid and

electric vehicles such as A/C compressor, power steering pump, cabin heater etc.

‣ NVH investigation on electric and low noise vehicles regarding their audio-acoustic interaction with the

environment for safety reasons (at low speed in urban environment)

C. Specific research in tyre-road noise generation and propagation with focus on electric

vehicles, heavy duty vehicles and urban transport

‣ Investigation of tyre-road noise generation of electric vehicles and heavy duty vehicles especially in

urban traffic under steady and transient driving conditions (such as braking, curves, acceleration etc.)

‣ Quiet road infrastructure (such as road surfaces and noise barriers) dedicated to urban areas for less

generation of tyre-road noise and reduction of noise propagation to surrounding (residential) areas

(focus on low vehicle speed)

‣ Investigation of tyre-road noise and road surfaces dedicated to sub-urban areas and motorways in

order to reduce noise generation and propagation (focus on higher vehicle speed)

‣ Balancing of tire/road noise with propulsion noise for adaptation of tire noise regulation and

optimization of acoustic directivity of tyre noise in interaction with other exterior acoustic (warning)

sources to reduce overall noise pollution and maximize vehicle detectability

‣ Characterisation, analysis and reduction techniques for rolling-induced interior vehicle NVH phenomena

D. New and advanced NVH analysis tools as driving factors for enhanced sustainability of

road transport and increased competitiveness of vehicle design within the European Union

‣ Improved concept modelling tools for more efficient frontloading of the NVH attributes in the

engineering design process to early design stages with a focus on (i) the adequate treatment of

inherent uncertainty and variability effects, (ii) the development of modelling paradigms for sound

quality design and (iii) the development of system cascading processes for target-setting and preoptimization

of subsystems

‣ Development of next generation simulation tools with enhanced prediction accuracy by tackling the

current limiting factors: improved dynamic source models, more appropriate models to tackle the

various damping mechanisms and dedicated numerical models for representation and design of novel

acoustic materials (e.g. multi-layer trim, meta-materials, etc.)

‣ Adaptation of models allowing holistic system optimization by considering NVH in a multi-physical

setting by coupling computational fluid dynamics (CFD) with acoustic approaches for reliable prediction

of flow-induced noise and vibration (e.g. in intake and exhaust systems, wind noise etc.) and by

coupling with 1D mechatronic models allowing accurate full vehicle optimization of (semi-)active NVH

systems such as vibration cancellation, warning devices and active safety systems, including real-time

(hardware-in-the-loop) applications

‣ New holistic analysis and development approaches for fuel-minimization of low carbon engines linking

sophisticated calibration algorithms with the NVH requirements regarding combustion and DI injection

equipment and with other performance criteria


European Automotive Research Partners Association aisbl

36-38 Rue Joseph II B-1000 Brussels, Belgium


‣ New test approaches for future propulsion topologies like hybrid, plug-in hybrid and electric vehicles

with/without range extender, allowing simultaneous investigation of all involved components and

systems regarding NVH, performance, durability, etc.

The EARPA Task Force NVH sees the requirement to carefully identify research topics on a European level

in close co-operation with all relevant stakeholders. Taking advantage of their expertise, EARPA members

can offer support to this identification process on a neutral basis. Moreover, EARPA invites all stakeholders

to discuss the above research issues with the Task Force NVH.

The EARPA Noise Vibration & Harshness Task Force


NVH TF Chairman

Bert Pluymers, KU Leuven

Tel: +32 (0) 16 32 24 80


More information on EARPA at: www.earpa.eu

NVH TF Secretary

Manfred Haider, Austrian Institute of Technology

Tel: +43 (0) 50 550 6256



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