Browse Topic: Acoustics

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Implementation Of Machine Learning In Acoustics Source Detection by Leveraging Synthetic Sound Data Generation Approach2024-26-021301/16/2024
E-Mobility and Low Noise IC Engines has pushed product development teams to focus more on sound quality rather than just focus on reduced noise levels and legislative needs. Further more qualification of products from a sound quality perspective from an end of line testing requirement is also a major challenge. End of line (EOL) NVH testing is key evaluation criteria for product quality with respect to NVH and warranty. Currently for subsystem or component level evaluation, subjective assessment of the components is done by a person to segregate OK and NOK components. As human factor is included, the process becomes very subjective and time consuming. Components with different acceptance criteria will be present and it’s difficult to point out the root cause for NOK components. In this paper, implementation of machine learning is done for acoustic source detection at end of line testing. To improve the fault detection an automated intelligent tool has been developed for subjective to
Shukle, Srinidhi, Iyer, Ganesh, Faizan, Mohammed
Characterization and Prediction of Interior Noise Quality in Electric Vehicles through Drive Unit End-of-Line Testing (EOLT)2025-01-003905/05/2023
This paper addresses the critical aspect of interior noise quality in electric vehicles (EVs), focusing on the characterization and prediction methodologies employed during drive unit end-of-line testing. The electric drive unit plays a pivotal role in determining the overall Noise, Vibration, and Harshness (NVH) quality of the final product. This study explores the impact of drive unit assembly process variation and individual component tolerance on the NVH characteristics of electric drive units, emphasizing their direct effect on overall vehicle acoustic quality and customer comfort. The research delves into the intricate relationship between drive unit vibrational response, vehicle interior noise, and customer subjective perception, providing valuable insights into their correlation and how they collectively influence user experience and satisfaction. It aims to enhance the understanding of how electric drive unit characteristics contribute significantly to the interior noise
Arvanitis, Anastasios, Parbat, Aniket, Jadhav, Prashant, Raphael, Andrew
Sound quality centered measurement technique over 40+ years: experiences and perspectives2025-01-007305/05/2023
The author’s life work in acoustics and sound quality, though continuous over more than 40 years, has followed a number of parallel and nonparallel paths all involving measurement technologies and their evolution. The illustrated discussion begins at the Research and Development Division of Kimball International, Inc. (Jasper, Indiana) in 1976 with piano research using a Federal Scientific Ubiquitous analog real-time FFT analyzer and Chladni-plate-mode studies with fine sand and high-speed photography of sound board modes excited by various notes and damper pedal positions. It continues at Jaffe Acoustics, Inc., a concert-hall-specializing consultancy in Norwalk, CT, with early-reflection plotting using a parabolic microphone on an altazimuth angular-readout mounting and either photographing oscillograms, or running a high-speed paper chart printer, assembling “wheel plots” incremented every 10 degrees in azimuth and altitude to map reflection patterns. Involvement with binaural
Bray, Wade
Cabin noise modeling for seat location variation using AI and Machine Learning2025-01-012905/05/2023
Analyzing acoustic performance in large and complex assemblies, such as vehicle cabins, can be a time-intensive process, especially when considering the impact of seat location variations on noise levels. This paper explores the use of AI and machine learning to streamline this analysis by predicting the effects of different seat configurations on cabin noise, particularly at the driver’s ear level. The study begins by establishing a baseline simulation of cabin noise and generating training data for various seat location scenarios. This data is then used to train an AI model capable of predicting the noise impact of further seat adjustments. These predictions are validated through detailed simulations. The paper discusses the accuracy of these predictions, the challenges encountered, and provides insights into the effective use of AI and machine learning in acoustic analysis for cabin noise, with a specific emphasis on seat location as a key variable. Keywords: Acoustic analysis, AI
Kottalgi, Santosh, Banerjee, Bhaskar
Acoustic characterization of AC motor using sound intensity in standard laboratory environments2025-01-001005/05/2023
Sound power is commonly used metric to quantify acoustic sources like AC motor in electrified powertrain. This testing is often performed in an anechoic environment to create free-field conditions around the unit. To eliminate the influence of extraneous noise sources, the anechoic facilities must be further isolated from driver and absorber dynamometers. These dynamometers are needed for running the AC motors in the desired speed and load conditions. For early detection of potential issues, it is advantageous to have the capability for engineers to conduct acoustic tests in standard laboratory environments. These may include non-acoustically treated rooms, presence of extraneous noise sources (e.g., driver and absorber dynos), etc. In such environments, sound intensity-based sound power determination methods could be utilized. The sound intensity-based approach is covered in ISO 9614 standard. The norm is to sweep an intensity probe on a sound source in constant speed condition to
Kumar, Aditya, Ippili, Rajani
A study on active sound design and control method for vehicle interior hybrid noise to enhance sound quality2025-01-001105/05/2023
With the current popularity of new energy vehicles and the continuous development of intelligent cabin technology, the demand for acoustic comfort within automotive cockpit is increasing. A multi-channel feedforward active sound design and control method was proposed to improve the sound quality of the hybrid broadband and narrowband noise inside the test vehicle. The method selectively designed the target amplitudes for broadband noise and narrowband noise in the vehicle to satisfy passengers comfort, mainly including the sound design phase and the control phase. During the sound design phase, objective sound quality parameter analysis was first conducted on the noise of the prototype vehicle, followed by an evaluation of the sound quality with semantic differential method. An active acoustic design strategy focusing on comfort, motivation sense and annoyance perception were proposed, including a formula for the target amplitude of adjustment order and sound pressure level. The sound
Liu, Xuexian, Xu, Wenxuan
Prediction and Optimization of Noise radiation from a Heavy-Duty Commercial Vehicle Transmission using Statistical Energy Analysis2025-01-005105/05/2023
Heavy Duty (HD) linehaul vehicles are majorly used in transportation of goods and heavy loads between different cities or long distances. Considering the current trend, payload capacity of these heavy-duty trucks are increasing due to constant increase in the load demand. Due to which engine torques of these HD vehicles are increasing which in turn increases the transmission input torque. At higher torque levels, gear excitation also increases and transmission becomes more susceptible towards higher noise radiation. Global vehicle pass-by noise regulations for HD commercial vehicles are becoming more stringent. Historically transmissions have been considered a secondary noise source but with overall HD vehicle noise becoming quieter, the transmission can be more of a significant noise contributor. Hence, noise radiation from the transmission is also an important factor to be considered in the design phase. Gear whine is the major concern for sound radiation from the transmission. The
Rastogi, Sarthak, Milind, T. R.
Effects of acoustic dissipative material in applications with acoustic leakage2025-01-011705/05/2023
In the paper, the dissipative material and other conventional acoustic materials are studied in conditions which simulates actual vehicle application with acoustic leakage. The various acoustic materials are evaluated in the lab with acoustic leakage existing in steel panel experimentally and virtually in computer simulation with the estimated Biot’s parameters of the materials. Often, the acoustic leakages exist in actual vehicle condition in pass-through or mounting faster locations. The work includes in-vehicle test results on application and show how the dissipative material works.
Yoo, Taewook, Maeda, Hirotsugu, Sawamoto, Keisuke, Anderson, Brian, Gan, KimTong, Herdtle, Thomas
Metamaterial application to automotive glass for vibration reduction and reduced noise transmission2025-01-011905/05/2023
A metamaterial which, attached to the edge of a panel, reduces vibration results in reduced noise transmission into a vehicle. In this particular case, the metamaterial is designed to be attached to the edge of a glass panel and can reduce panel vibration and noise transmission due to wind or other sources into the vehicle interior. Acoustic transmission loss and panel vibration assessments show the benefit of this approach.
Sorenson, Steve, Moore, Jaime, Robison, Scott, Li, Xiaopeng
Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis2025-01-005805/05/2023
To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.
Yang, Wenlong, MELO, ANDRE
Directivity driven simulation methodology for efficient Acoustic Encapsulation2025-01-004805/05/2023
Noise Reduction at the source level is critical to achieve the overall vehicle level interior targets. This method presents a novel approach that integrates directivity analysis with simulation techniques to optimize acoustic encapsulation design for automotive sound sources to achieve the targeted radiation levels. The foundation for this methodology is to measure the angular distribution of sound pressure levels around the noise source so called Directivity, at every frequency of interest and determine the most effective Acoustic encapsulation to achieve the targeted sound radiation. Accurate measurement of directivity in physical testing with fine angular resolutions can be complex and expensive, this study utilizes numerical simulation techniques using FEA to mitigate the challenges in mid frequency range. The scope of the study is focused on mid frequency sound pressure levels between 500-2000 Hz, which are determined to be significant contributors to overall DU noise. The first
KALUVAKOTA, SRIKANTH, Ghaisas, Nikhil, Pilz, Fernando
The applications of Acoustic Black Holes to attenuation of Coach/Bus Frame Structure Vibrations2025-01-006505/05/2023
Abstract An acoustic black hole (ABH) is a structure whose cross-sectional thickness decreases exponentially to zero, and the phase velocity and group velocity of wave propagation in those structure acoustic black holes decrease as the thickness decreases until they are zero. ABH produce some very magical physical phenomena. For example, because the wave velocity decreases to zero, the wave can never reach the center of the ABH, so the wave propagation in the acoustic black hole has neither refraction nor reflection; that is to say the vibration wave will not go through the acoustic black hole. As a result, the wave energy is concentrated in the center of the ABH. The arrangements of those acoustic black holes in the structures could change the directions of the vibrational wave propagation in the structures at NVH engineers’ wills. These amazing phenomena could play a magical role in reducing structural vibration, structural noise radiation and structure-borne noise. Basic structures
Huang, Xianli
Fast noise prediction of an electric powertrain integrated in various vehicles2025-01-007605/05/2023
The automotive industry's transition to electrification raises new challenges to maintain a comfortable acoustics environment both inside and outside the car. This paper presents an innovative way to make an early prediction of the overall sound of a vehicle at driver’s ear by mixing noise sources that can be simulated and noise sources that can be measured at component level. This hybrid approach combining Test and Simulation data helps make decisions in the early design phase by predicting the noise of one component integrated in the whole vehicle. For instance, Valeo, with the help of sound synthesis techniques, is able to predict the sound of an e-drive when it is combined with Rolling noise that varies depending on the vehicle speed and the car segments - more or less refined, from a dataset of multiple vehicles. Realistic signals could be generated and compared with actual acoustic measurement to validate the method.
Redon, Milan, Dendievel, Clement, Pluton, Matthias
Acoustic Evaluation of Fiber Based Materials for Engine Bay Applications2025-01-011505/05/2023
A newly formulated fiber-based material was developed to offer a cleaner, recyclable alternative to foam-based vehicle acoustic products. The fiber-based material was designed to be used in multiple vehicle acoustic applications, with different blends of the material available depending on the application. It performs well as an engine bay sound absorber due to its high heat tolerance and good absorption performance. A study was conducted to evaluate the sound absorption performance of this fiber-based material, specifically the engine bay blends, in comparison to that of current foam-based products. The results from this study show that the sound absorption performance of this new fiber-based material can match that of current foam-based materials while providing a recyclable product unlike the foam.
Krugh, Jack
Active Control of Engine Order Noise for Heavy-duty Trucks: Using the Genetic Algorithm for the Optimization of Error Microphone Arrangement2025-01-001305/05/2023
The arrangement of error microphones for a vehicle active noise control (ANC) system is no trivial work, especially for heavy-duty trucks due to the dilemma resulted from the large volume of the cab and the limited number of microphones accepted by most manufacturers in the auto industry. Most ANC developers resort to trial and error, which is not only a heavy workload given the amount of interested working conditions to be test, but also does not guarantee to yield the optimum noise cancellation performance. In this paper, the authors proposed an error microphone selection methodology using a genetic-algorithm (GA) -based mechanism. The target vehicle was a heavy-duty truck with a six-piston diesel engine, and two scenarios were particularly interested, i.e. driver & copilot and driver & one passenger sleeping on the berth. We first arranged eight microphones at different locations in the cab, five on the headrests, two on the B pillars and one at the head position of the sleeping
Wang PhD, Jian, Ling, Zihong, Zhang, Zhe, Cai, DeHua, lv, Xiao, Zhang, Ming, Gao, GuoRan
Subjective development of EV propulsion noise to drive product differentiation2025-01-006705/05/2023
The frequency and amplitude content of powertrain noise is motor torque and speed dependent and tends to influence the driver’s subjective perception of the vehicle. This provides manufacturers with an opportunity to drive product differentiation through consideration of powertrain noise in early stages of the development cycles for electric vehicles (EVs). This paper focuses on evaluation of customer perception to acoustic feedback of motor design options based on targeted motor orders and expected wind and road masking during high acceleration maneuvers. A jury study is used to explore the customer feedback response to a two-stage gearbox design with AC permanent magnet motor order combinations. The subjective influence of order spacing, dominant frequency content and the number of audible tones is studied to understand aural perspective product differentiation opportunities.
Joodi, Benjamin, Jayakumar, Vignesh, Conklin, Chris, Pilz, Fernando, Iyengar, Shashank, Weilnau, Kelby, Hodgkins, Jeffrey
Tonal noise investigation of automotive HVAC systems : a hybrid method2025-01-002705/05/2023
There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of
Bennouna, Saad, Alaoui, Mohamed
Application of Hybrid SEA in Vehicle NV Package Optimization2025-01-005005/05/2023
As India’s economy expands and road infrastructure improves, the number of car owners are expected to grow substantially in the coming years. This market potential has intensified competition among original equipment manufacturers (OEMs) to position their products with a focus on cost efficiency while delivering a premium user experience. Noise and Vibration (NV) performance is a critical differentiator in conveying a vehicle's premiumness, and as such, NV engineers must strategically balance the achievement of optimal acoustic performance with constraints on cost, mass, and development timelines. Traditionally, NV package optimization occurs at the prototype or advanced prototype stage, relying heavily on physical testing, which increases both cost and time to market. Furthermore, late-stage design changes amplify these challenges. To address these issues, this paper proposes the integration of Hybrid Statistical Energy Analysis (HSEA) into the early stages of vehicle development
Rai, Nitesh, Mehta, Makrand, Ravindran, Mugundaram
Excavator exterior noise contribution analysis using angle-based operational acoustic load synthesis.2025-01-006205/05/2023
Since earth moving machines (EMM) are subject to exterior noise (EN) regulations, OEMs need to develop mitigation solutions from an early design stage. It is challenging to predict solution effectiveness at early design stage. Excavators are distinct compared to other EMM as their upper frame rotate while keeping lower frame fixed. ISO 6395(2) or EC/2000/14(1) require EMMs to follow specific operating maneuvers where noise sources change their position, directivity, and speed along the operating cycle. These conditions pose challenges in performing noise contribution analysis as a function of angular position and operating condition. Authors successfully demonstrated Acoustic source quantification and contribution analysis for linearly moving EMMs. However, excavator pose data processing challenges due to angular motion. This work demonstrates the use of frequency domain ASQ for operational acoustic source quantification and use of frequency domain virtual prototype sub structuring
Vesikar, Prasad Balkrishna, Haynes, Timothy, Aquino Arriaga, Adrian Antonio, Drabison II, John, Chaduvula, Prasanna
Hybrid 3D Sound Intensity and Simulation for Optimizing Acoustic Output of Truck Rear Axles2025-01-010505/05/2023
This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations, focusing on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions. While the current application focuses on the truck's rear axle far-field radiation, the same method can be extended to predict in-cabin sound pressure, providing a versatile solution for many industrial problems.
Fernandez Comesana, Daniel, Vael, Georges, Robin, Xavier, Orselli, Joseph, Schmal, Jared
Feasibility of In situ vehicle level transmission loss measurement to guide dash pass through grommet selections2025-01-012205/05/2023
Noise transmission through the vehicle dash panel plays a critical role in isolating passengers from noise sources within the motor bay of the vehicle. Grommets containing electrical harness routing as well as HVAC lines are examples of dash panel pass throughs that should be selected with care. Acoustic performance of these components is generally characterized in terms of measured quantities such as noise reduction (NR), sound transmission loss (STL), and Insertion Loss (IL). These measurements need to be carried out as per SAE or ASTM standards in appropriate anechoic or reverberant chambers as this is important for consistency. This work explores an in-situ vehicle measurement setup utilizing a repurposed vehicle cabin designed to serve as an anechoic chamber with its frunk acting as a reverberant chamber. This in-situ setup method is then compared to results following standards to discuss the differences in results. The data is studied to understand if there are any advantages to
Joodi, Benjamin, Jayakumar, Vignesh, Chang, Michael, Geissler, Christian, Pilz, Fernando, Conklin, Chris
Comprehensive EV Sound Design project from Marketing Requirements to Series2025-01-001805/05/2023
This paper presents the results of a project to design new comprehensive sound sets for several electric vehicle models having each specific branding expectations. This was achieved thanks to a close collaboration between one major Chinese electric vehicle manufacturer and an acoustic software provider, relying on shared experience, knowledge, and tools to meet the initial requirements set. Firstly, a scenarized journey and brand-related symbolism were defined and served as a basis for creating meaningful sketches of sound design in a cross-team effort (designers, NVH, production, audio system, etc.). Various sound functions were considered for exterior sounds, such as AVAS, and interior sounds, such as ambiance, HMI, and alarms. A special care was dedicated to the so-called Active Sound Design aiming at providing speed and acceleration feedback to the driver, in the absence of a clearly audible engine noise. A listening test was then conducted in order to assess how the proposed
LI, Yanhao, Minard, Antoine, Boussard, Patrick, Zhang, Charles
Do EVs Snore?2025-01-007405/05/2023
As EV and PHEV adoption continues to increase more people will have direct experiences with these quieter vehicles in their daily lives. Topics such as 'propulsion sound' via Active Sound Design (ASD) and bystander safety through Acoustic Vehicle Alerting Systems (AVAS) have been discussed widely for many, many years...but who is talking about Charging Noise? Charging noise is a less spoken about topic because most EV / PHEV owners will charge their vehicles at their home, in their garage or their driveway, overnight when they are sleeping. Because of that people do not think much about charging noise. But anyone who has plugged in their car overnight will tell you a strange cacophony of sounds come from the car...and some can be downright concerning. In this paper data from several production EVs were measured during their normal charging cycle. Binaural recordings made inside and outside the vehicle are analyzed using psychoacoustics metrics to see what sounds would cause the most
Marroquin, Marc, Bray, Wade
Identification and Evaluation of Passthroughs That Affect the Acoustic Performance of a Dash System2025-01-012105/05/2023
This paper discusses a systematic process that was developed to evaluate the acoustic performance of a production electric vehicle dash system. The production dash panel was tested under different configurations to understand the importance of passthroughs in the acoustics of the dash system. Results show that often the performance of the passthroughs strongly affects the overall performance of the dash system and this may become the limiting factor to increase the system STL. The dash with passthroughs was then extensively tested to understand the acoustic strength of different passthroughs and to understand how these passthroughs affect the overall performance of the dash system. Subsequently a test procedure based on flat panel tests was developed so the OEM can develop target values and the suppliers can provide test results of their passthroughs that are meaningful and useful to the OEM to help build an acoustically competitive vehicle.
Saha, Pranab, Baack, Gregory, Geissler, Christian, Kaluvakota, Srikanth, Pilz, Fernando
Localisation of Ultra-short Sound Emissions from Automotive Components by Using the Sound Field Scanning Method2025-01-009205/05/2023
Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from
Rittenschober, Thomas
Sound Design for Electric Vehicles: Enhancing Safety and User Experience Through Acoustic Vehicle Alerting System (AVAS)2025-01-006805/05/2023
Silent engines are an excellent strategy to combat noise pollution. Still, they can pose risks for pedestrians who rely on auditory cues for safety and reduce driver awareness due to the absence of the familiar sounds of combustion engines. Sound design for silent engines not only tackles the above issues but goes beyond safety standards towards a user-centered approach by considering how users perceive and interpret sounds. This paper examines the evolving field of sound design for electric vehicles (EVs), focusing on Acoustic Vehicle Alerting Systems (AVAS). The study analyzes existing AVAS, classifying them into different groups according to their design characteristics, from technical concerns and approaches to aesthetic properties. Based on the proposed classification, an (adaptive) sound design methodology, and concept for AVAS are proposed based on state-of-the-art technologies and tools (APIs), like Wwise Automotive, and integration through a functional prototype within a
Esteves, Raquel, Campos Magalhães, Eduardo Miguel, Bernardes, Gilberto
Evaluation of invariant structural and acoustic loads estimation methods to be used in vehicle platform development independent to the boundary conditions of load generation.2025-01-005305/05/2023
Platform based vehicle development is standardized at Deere. The challenges of frontloading the integration effects of individual components within different platforms using predictive methods is key to shorten the development cycle. Components are generally characterized on test benches and can not directly be used to evaluate system performance. Invariant characterization is needed which is possible through techniques such as blocked loads estimation. To evaluate the applicability of such methods, the test stand based, and vehicle in-situ operational loads needs to be compared. The confident use of these methods for structural and acoustic loads enables the use of combination of test and simulation models of common components and system modules in a variety of products, enhancing early NVH response predictions. In this work, we compare a powertrain characterization in a vehicle and a test stand to assess the invariance of the operating mount structural loads as well as operating
Vesikar, Prasad Balkrishna, Edgington, Jason, Drabison II, John, Chaduvula, Prasanna
Cairene Car-Culture: How are Automobility and Social Behavior Linked to The Development of The Soundscape and Urban Fabric of Cairo.2025-01-006905/05/2023
Cairo’s soundscape has witnessed changes due to the ongoing urban structure developments that accommodate the number of vehicles passing through the city. The soundscape produced by this growing automobility is affected not only by vehicles but also by their owners' behavior. Cairenes use their cars as a communication tool and an extension of private space. By viewing the vehicle as a component of the soundscape as well as a space that filters it, this study examines the synergy between social behavior, automobility, urban structure, and their interdependent relationship on the soundscape of Cairo. The study responds to literature elaborating on acoustic ecology, car culture, urban structure, and social behavior. The methodology applied in this study follows practice-based phenomenological research while documenting and reflecting on car cultural practices in Cairo from an aural perspective. Grounded theory contextualizes the analysis of archived audio and video material, semi
Abd El Naby, Abla Mohamed
Evaluation of Automotive Closure Design for High Frequency Acoustics Performance2025-01-004905/05/2023
A good NVH environment in a vehicle plays an important role in attracting a large customer base in the automotive market. Hence, NVH has been given significant priority while considering automotive design. NVH performance is monitored using simulations early during the design phase and testing in later prototype stages in the automotive industry. Meeting NVH performance targets possesses a greater risk related to design modifications in addition to the cost and time associated with the development process. Hence, a more enhanced and matured design process involves Design Point Analysis (DPA), which is essentially a decision-making process in which analytical tools derived from basic sciences, mathematics, statistics, and engineering fundamentals are used to develop a product model that better fulfills the predefined requirement. This paper shows the systematic approach of conducting a Design Point Analysis-level NVH study to evaluate the acoustic performance of vehicle door systems in
Ranade, Amod A., Shirode, Satish, Miskin, Atul, Mahamuni, Ketan, Shinde, Rahul, GHAN, PRAVIN, Choudhury, Ashok
Synergy of Methods in Structural Dynamics: TPA and Modal Analysis2021-01-109008/31/2021
Since NVH is always a property of the whole system, one must have a deep understanding of the dependencies and all the components that interact. The well known in-situ Transfer Path Analysis (TPA) provides methods to separate different components of an acoustical system such as source and receiver. The source including excitation and structural dynamics of the exciting subsystem can be described independently of the structural dynamics of the receiving structure by means of the in-situ blocked forces. The Experimental Modal Analysis (EMA) is a common method as well and aims to identify the structural dynamics of a structure. This paper addresses the combination of both methods using the example of an e-drive of an electric car, which has been analyzed on a test rig. The combination of modal analysis and TPA yields a better understanding of the system and its dependencies. The correlation of the results of both methods can be used to gain important insights regarding the source
Wegerhoff, Matthias, Sottek, Roland, Brücher, Haiko, Kamper, Tim
Interior Floor Engineering: Acoustic vs. Compression Performance2021-01-112908/31/2021
The interior floor of a vehicle cabin occupies a significant amount of surface area in proportion to the cabin as a whole, and as such provides a prime opportunity for acoustic treatment. Generally speaking, floor materials must be relatively limp to achieve high acoustic performance. However, the tactile quality of a vehicle floor is very important. The end customer has an expectation for how it should feel to step onto the floor of a vehicle: a carpet should “give” slightly, but not compress fully, under pressure. A carpet that is too stiff or not stiff enough may be perceived as indicative of low quality. Thus, acoustic targets and stiffness targets tend to be at odds. A vehicle interior floor is a trim component which consists of different layers and which can have different pile-up configurations. Such a pile-up typically consists of a soft layer, called a decoupler, and a top layer. Previous work has shown how CAE tools can predict part-level compression behavior during design
Frey, Andrea, Koeske, Ben, Li, Wanlu, Wichmann, Brandon
Design Improvement on Condenser Assembly under Dynamic Behaviour through Vibro-Acoustic Analysis2021-01-106508/31/2021
The automotive air-conditioning (AC) components fitted on passenger car having high vibration make significant impact on vehicle noise and harshness inside the cabin. Hence, it is necessary to reduce the vibrations within the permissible limit. This can be done by improving dynamic behavior of the assembly under vehicle fitments. The present paper explains about design improvement carried out on the condenser assembly to increase strength of the mounting brackets as well as to reduce the noise level by reducing the vibrations. Modal frequency response analysis has been performed on the existing condenser and found that there was relatively high vibration on the assembly due to low stiffness of the bracket. From the acoustic analysis, it was observed that the noise is occurring due to high vibration at resonance condition. By doing the design changes on the assembly, modal frequency increased relatively. Accordingly, noise level also reduced. The Vibro-acoustic analysis predicted the
Bora, Dipankar, Parayil, Paulson, Meena, Avadhesh
Study of the Effects of Active Noise Cancellation on Music Playback2021-01-101608/31/2021
Technology for automotive active noise cancellation (ANC) such as HARMAN’s Engine Order Cancellation (EOC) system help reduce in-cabin noise levels using a set of error microphones and the vehicle’s built-in audio system to generate anti-noise signals. A major benefit of these systems is that significant reduction in unwanted noise levels in the 20 - 400 Hz range can be achieved without the addition of extra noise control material. However, in the instances where the frequencies of anti-noise signals and music signals overlap, a degradation in the overall music reproduction quality is possible. In this paper, we study the effects of EOC on music playback by applying signal processing and statistical methods to objectively measure degradation in audio content when EOC is active. This study is carried out using production EOC software in a simulation environment. The simulation models the cabin acoustic response from measured vehicles and uses recordings of vehicle noise and music as
Basu, Sattwik, Tackett, Jeffrey, Trumpy, David, Walt, Adam, Adari, Santosh
Engine Sound Source Characterization Based on Inverse Numerical Acoustics2021-01-102408/31/2021
Inverse Numerical Acoustics (INA) is the process by which the measurements of the sound pressure near a vibrating object, such as an engine, can be used to reconstruct the surface velocities of the object. This is required when it is difficult to conduct measurement on the structure or when the full structural FE model is not available. In such scenarios, the INA technique allows to back calculate the operational vibrations based on operational near field pressure measurements. When the surface velocities of a vibrating object are known which are independent of the boundary conditions, then the object can be used as a source in any application to compute the sound pressure levels in the surrounding (far field). This paper describes an experimental procedure that relies on INA to characterize an engine noise source in this manner. To this end, a robotic manipulator first measured sound pressures at multiple points in the near acoustic field. This process resulted in an accurate mapping
Chaudhari, Parag, Cuhat, Daniel, Smith, Corey, Marry, Christopher, Suh, Sanghoon
Utilizing Engine Dyno Data to Build NVH Simulation Models for Early Rapid Prototyping2021-01-106908/31/2021
As the move to decrease physical prototyping increases the need to virtually prototype vehicles become more critical. Assessing NVH vehicle targets and making critical component level decisions is becoming a larger part of the NVH engineer’s job. To make decisions earlier in the process when prototypes are not available companies need to leverage more both their historical and simulation results. Today this is possible by utilizing a hybrid modelling approach in an NVH Simulator using measured on road, CAE, and test bench data. By starting with measured on road data from a previous generation or comparable vehicle, engineers can build virtual prototypes by using a hybrid modeling approach incorporating CAE and/or test bench data to create the desired NVH characteristics. This enables the creation of a virtual drivable model to assess subjectively the vehicles acoustic targets virtually before a prototype vehicle is available. This approach can also be used with, but not limited to
Thom, Brian, Singh, Vinod, Newton, Gary, Rengarajan, Revathi, Radic, Nebojsa
Identification of Low-Frequency/Low SNR Automobile Noise Sources2021-01-106208/31/2021
This paper presents experimental investigations of determining and analyzing low-frequency, low-SNR (Signal to Noise Ratio) noise sources of an automobile by using a new technology known as Sound Viewer. Such a task is typically very difficult to do especially at low or even negative SNR. The underlying principles behind the Sound Viewer technology consists of a passive SODAR (Sonic Detection And Ranging) and HELS (Helmholtz Equation Least Squares) method. The former enables one to determine the precise locations of multiple sound sources in 3D space simultaneously over the entire frequency range consistent with a measurement microphone in non-ideal environment, where there are random background noise and unknown interfering signals. The latter enables one to reconstruct all acoustic quantities such as the acoustic pressure, acoustic intensity, time-averaged acoustic power, radiation patterns, etc. By combining a passive SODAR and modified HELS methods, engineers will be able to
Lu, Yazhong, Wu, Sean, Yuan, Zeyu, He, Wen, Li, Zhaoting, Li, Huijun
Efficient Integrated Vibro-Acoustic Simulation Methods2021-01-105508/31/2021
The new trends in industry with for instance the electrification of systems leads to new challenges in the domains of acoustics and vibrations. The tonal noise of electric machines and their gearboxes, masked by the internal combustion engine in traditional vehicles, can now be significantly perceived by passengers, resulting in acoustic discomfort. Industry engineers now need to spend substantial effort in understanding the noise and vibration behavior of such components, with the main objectives of decreasing the weight for functional performance and reducing unpleasant sounds. Efficient vibro-acoustic simulation methods are then necessary to achieve these goals, starting from the modelling techniques up to the actual computation and solution post-processing. A complete workflow fully integrated within a single software platform is shown in this paper to achieve the simulation of a gearbox housing exterior radiation. Multiple physical aspects are included in this numerical solution
Hamiche, Karim
Performance Evaluation of Eastman’s Saflex® E Series Acoustic Interlayer2021-01-105408/31/2021
In 2020, Eastman launched a new acoustic PVB interlayer for automotive laminated glass. This interlayer not only helps to protect driver and passengers from injuries during impact but also provides enhanced acoustic comfort in the car. This newly developed interlayer offers substantially improved acoustic performance in the high-frequency range that is typically associated with wind noise at higher vehicle speeds. To demonstrate the in-vehicle performance, finite element simulations have been carried out using wind noise as the principal source of excitation. The results confirm previously published data that the acoustic contribution overwhelms the turbulent part, having a larger contribution to the ultimate acoustical pressure level. The acoustic insulation calculated is in excellent agreement with the static sound transmission loss data as measured according to the ISO or ASTM norm. In cases where both the windscreen and front-side windows have a laminated structure, a large
D'Haene, Pol, Van de Vyver, Stijn, Poulos, Athanasios, Robin, Xavier
Analyses of Low-Frequency Motorcycle Noise Under Both Steady-State and Transient Operating Conditions2021-01-110808/31/2021
This paper presents experimental investigations of diagnosing and analyzing the low-frequency, low- SNR (Signal to Noise Ratio) noise sources of three motorcycles using a hybrid technology that consists of a passive SODAR (Sonic Detection And Ranging) and modified HELS (Helmholtz Equation Least Squares) methods. The former enables one to determine the precise locations of multiple sound sources in 3D space simultaneously over the entire frequency range that is consistent with a measurement microphone in non-ideal environment, where there are random background noise and unknown interfering signals. The latter enables one to reconstruct all acoustic quantities such as the acoustic pressure, acoustic intensity, time-averaged acoustic power, radiation patterns, and sound transmission paths through arbitrarily shaped vibrating structures. By combining a passive SODAR and modified HELS methods, engineers are able to reveal the low-frequency noise sources that cannot be accomplished by using
Lu, Yazhong, Wu, Sean, Yuan, Zeyu, He, Wen, li, Zhaoting, Li, Huijun
Hybrid Laminated Panels Addressing Acoustic Issues in Vehicles2021-01-108608/31/2021
Laminated steel body panels are used in different applications in vehicles, such as dash panels and wheel wells. A part made out of laminated steel has the potential to provide structure-borne noise reduction and also improve the airborne noise reduction of the part compared to a monolithic part. The use of laminated steel has been more critical when there are deep draws on the part as the deep draws cause localized resonances which degrade the acoustic performance significantly. However, due to lightweighting demands, hybrid laminated panels, commonly known as acoustic patch laminates have become very attractive. This paper discusses the damping and sound transmission loss performances of a dash panel part with monolithic, laminated, and acoustic patch panels. The paper discusses the damping performance below 1000 Hz, including the data analysis process and the effectiveness of the acoustic patch laminates for both structure borne and airborne noise studies including coincidence dip
Saha, Pranab, Patil*, Sagar, Figueroa**, Antonio, Telenko, Michael
Multiphysics Simulation of Electric Motor NVH Performance with Eccentricity2021-01-107708/31/2021
With the emphasis of electrification in automotive industry, tremendous efforts are made to develop electric motors with high efficiency and power density, and reduce noise, vibration and harshness (NVH). A multiphysics simulation workflow is used to predict the eccentricity-induced noise for GM’s Bolt EV motor. Both static and dynamic eccentricities are investigated along with axial tilt. Analysis results show that these eccentricities play a critical role in the NVH behavior of the motor assembly. Transient electromagnetic (EM) analysis is performed first by extruding 2D stator and rotor sections to form 3D EM models. Sector model is duplicated to form full 360-degree model. Stator is split into three rotated sections to characterize stator skew, and the skew between two sections of rotor and magnets are also modelled. Sinusoidal current is applied and lumped-sum forces on each stator tooth are computed. Next, full 3D structural model is constructed, and EM forces are applied as
Zhang, Henry, Jaura, Ankur, Kumar, Dinesh, Sambharam, Tushar, Zhang, Zheming, He, Song, Zhang, Peng, GSJ, Gautam
Pass by Noise Analysis Method Extended for Mitigation Solution Development on Earth Moving Machinery2021-01-107108/31/2021
Pass-by/exterior noise of earth moving machines (EMM) and forestry machines is becoming a focus at early product development stages. ISO 6395 (2) or EC/2000/14 (1) standards defines exterior noise test procedure for EMM. However, these standards do not provide insights for diagnosing any noise issues which may arise. The analysis challenges are posed by the moving machine and acoustic sources with respect to the stationary hemisphere target microphone on the ground and changing operating condition of sources as function of time. There is need to develop a seamless methodology to identify acoustic sources, quantify respective source strengths and rank partial contributions from each source to the total target microphone response in order to overcome the aforementioned challenges. This paper demonstrates use of time and frequency domain Acoustic Source Quantification (ASQ) combined with time domain overall sound pressure level computation to mimic operational test conditions which
Vesikar, Prasad Balkrishna, Drabison II, John, Rawal, Abhay, Chaduvula, Prasanna, Wood, Cary, Sullivan, Joseph
Prediction and Validation of Cab Noise in Agricultural Equipment2021-01-107008/31/2021
To improve overall customer experience, it is imperative to minimize the noise levels inside agricultural equipment cab. Up-front prediction of acoustic performance in product development is critical to implement the noise control strategies optimally. This paper discusses the methodology used for virtual modeling of a cab on agricultural equipment for prediction of interior noise. The Statistical Energy Analysis (SEA) approach is suitable to predict high frequency interior noise and sound quality parameters such as articulation index and loudness. The cab SEA model is developed using a commercial software. The structural and acoustic excitations are measured through physical testing in various operating conditions. The interior noise levels predicted by the virtual model are compared with the operator ear noise levels measured in the test unit. The resultant SPL spectrum from SEA correlates well with the test. This model is used to optimize the noise control treatments and improve the
Mandke, Devendra, Fapal, Anand, Pawar, Sachin, Cone, Kerry
Subjective and Objective Seat Feature Acoustic and Vibration Response2021-01-107508/31/2021
Compressors, fans, and valves in seats used for occupant height adjust, lumbar, heating, and cooling can be objectionable if felt or heard. An approach to measure subjectively and objectively both vibration and noise experienced by a seated occupant will be described along with results, ranking, statistical significance, correlation, and suggestions for noise control. The objective portion included acoustic measurements through a binaural headset worn by each occupant and vibration measurements were recorded using a seat pad accelerometer disc at the buttocks and a source accelerometer. A subjective questionnaire with Likert, Borg, Magnitude Estimation, Semantical Differences, and Ranking based questions was obtained from 9 subjects. The transfer path the vibration energy takes to reach the receiver, vibration or acoustic, will be explored with transfer function measurements and a discussion of potential mitigation techniques: source mounting, encapsulation, and other design
Haylett, Jim, Romagosa, Francesc, Nelson, Erik
A Novel Dissipative Acoustic Material2021-01-112808/31/2021
Due to modern trends in the automotive industry, such as vehicle electrification, light-weighting, reduced NVH (Noise, Vibration and Harshness) packaging space, etc., it is desirable to have a low profile and light-weight acoustic material with multi-functionality. If one single layer of a thin acoustic material can provide comparable absorption and transmission loss to a multilayer treatment, it will benefit the industry by saving weight, packaging space and system cost. Acoustic absorption and sound transmission loss performance of a new dissipative material at reduced weight and thickness is introduced in this paper. The acoustic performance of the material was evaluated by using random incidence absorption and transmission loss as well as in-vehicle experiment. Further potential applications for this material have been identified using the Statistical Energy Analysis (SEA) method with panel leakage considered.
Yoo, Taewook, Gerdes, Ronald, Lee, Seungkyu, Shi, Tongyang
Monitoring Brake Wear with Acoustics2021-01-105308/31/2021
A new approach for detecting problems with vehicle brakes by analyzing sounds emitted during braking events is proposed. Vehicle brakes emit acoustic energy as part of the braking process; the spectra of these sounds are highly dependent on the mechanical condition of the brake and can be used to detect problems. Acoustic theory indicates that as brake linings wear thinner the resonant frequency of the shoe or pad increases, potentially enabling the monitoring of lining wear through passive acoustic sensors. To test this approach, passive acoustic sensors were placed roadside at the exit of a transit bus facility for 9 months. The sensors collected almost 10,000 recordings of a fleet of 160 vehicles braking over a variety of conditions. Spectra of vehicles that had brake work performed during this period were analyzed to compare differences between new and worn friction linings. It was found that the spectra changes as friction linings wear, in concurrence with acoustic theory, where
Hearing, Brian, Grove, Kevin, Alden, Andrew
Acoustic Model Reduction for the Design of Acoustic Treatments2021-01-105708/31/2021
Due to constant evolution in both noise regulations and noise comfort standards, noise reduction inside the vehicle remains one of the main issues faced today by the automotive industry. One of the most efficient methods for noise reduction is the introduction of acoustic treatments, made of multilayered trimmed panels. Constraints on these components, such as weight, packaging space and overall sound quality as well as the amount of possible material and geometrical combinations, have led automotive OEMs to use innovative methods, such as numerical acoustic simulation, so as to evaluate noise transmission in a fast and cost-effective way. While the computational cost for performing such analyses is insignificant for a limited number of configurations, the evaluation of multiple design parameter combinations early in the design stage can lead to non-viable computation times in an industrial context. This paper presents a framework for the efficient, almost real-time evaluation of
Poulos, Athanasios, Jacqmot, Jonathan, Baudson, Romain, Kayvantash, Kambiz, Le Corre, Sandrine
Root-Cause Analysis, and Improvement of a Port Fuel Injected V6 Vehicle to Achieve Best-In-Class Sound Quality2021-01-104108/31/2021
This paper will communicate an in-depth investigation uncovering contributing factors defining the desired and undesired acoustic signature of a V6 Vehicle. A transfer path analysis tool is exercised to rank improvement opportunities. These results are used to drive design improvements with the goal of achieving best-in-class sound quality when executed as a system. A cohesive powertrain-vehicle-level acoustic improvement package is executed, improving air induction, intake manifold, both structure and air-core, exhaust-radiated and under-hood-acoustic encapsulation. The acoustic package was validated by jury testing to provide significant refinement enhancement improving predicted 3rd party scores.
Brosseau, Justin, Yuan, Wei, Singh, Vinod, Orzechowski, Jeff
Performance Evaluation of Various Structural Damping Materials for Application in Electric Vehicles2021-01-112408/31/2021
The ongoing electrification of passenger car propulsion systems has an impact on vehicle acoustic quality due to the different excitation characteristics of electrical drives compared to internal combustion engines. The airborne noise and structural vibrations, induced by electric motor, have higher frequency components and they influence the application of acoustic countermeasures in the vehicle. One important element of these treatments is the structural damping package, which can include monolayer damping such as liquid applied sound damping (LASD) as well as bitumen or polymer-based dampers and various multilayer constraint layer damping materials. The performance of damping materials is commonly characterized by the loss factor and estimated by the well-known Oberst Beam Method. Major drawbacks of this method are the measurement limitations to composite loss factors less than 0.3, lower frequency range (less than 500 Hz) and the overall inability to evaluate materials in the
Unruh, Oliver, Fuhrmann, Bernd, Obst, Heike-Ursula
Metamaterials R&D TARGETS NVH ABATEMENT21AUTP05_0405/01/2021
Nissan readies its lightweight acoustic solution for 2022 production - will Hyundai follow? Acoustics engineers have a broad variety of materials from which to choose for reducing noise, vibration and harshness (NVH) in vehicles. But their selection often comes with a measurable downside: added mass. It's not uncommon for a new vehicle to gain 100 lb (45 kg) or more during development as various absorbers, reflective barriers and absorber-barrier combinations - typically baked-on mastics, blankets, injected foams and acoustic glazing - are brought to bear. In an era where “lightweighting rules” and engineers are rewarded on a per-gram basis for cutting vehicle weight, materials researchers are betting on new developments to win the NVH-versus-mass battle. So-called metamaterials offer significant promise here, with a potential added benefit of being less costly than the traditional NVH solutions used by OEMs.
Brooke, Lindsay
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