Browse Topic: Noise

Items (6,217)
Find
A Modular Method for Certified Virtual Validation of NVH Performance in Automotive Platforms2026-01-0684To be published on 06/20/2026
This work presents a modular engineering methodology (DigPhBalance - Digital Physical Balance) for the virtual validation of Noise, Vibration, and Harshness (NVH) performance in automotive development. The approach addresses the inefficiency of repeated physical testing across vehicle variants by introducing a structured two-phase process—Launcher and Reskin—centered on quantitative performance indicators with formal acceptance thresholds. In the Launcher phase, a digital replica of the base vehicle is built and iteratively correlated with physical test data. Validation is governed by objective indicators of confidence, conformity, and correlation, each evaluated against predefined thresholds. Once validated, the model becomes a certified reference, enabling its reuse across derivative configurations in the Reskin phase. Physical testing is only required if indicators fall below threshold, with a final gate test on pre-series vehicles ensuring industrial robustness. DigPhBalance
Celiberti, Lucia, Camia, Andrea
NVH Design and Refinement of Dedicated Hybrid Engine on Range Extender Electric Vehicle2026-01-0688To be published on 06/20/2026
Traditional NVH (Noise, Vibration, Harshness) refinement is reactive, addressing issues post-prototype. In contrast, this work establishes NVH as the primary driver in early engine development for range extender electric vehicles (REEVs). Customer demands for imperceptible engine operation [1] - intensified by absent masking noise in electrified powertrains [2] - necessitate a proactive methodology: Usage-Driven Operating Profile: Analysis of >500,000 km fleet driving data identified statistically dominant operating conditions. This enables precise NVH focus areas and proactive avoidance-zone definition in the engine operational map. Vehicle-Driven Target Setting: Subsystem-level NVH targets (e.g., <58 dB(A) idle noise → engine-level) were rigorously derived from vehicle imperceptibility requirements and the dominant usage profile. Preventive Design Optimization: Architectural choices (stiffness-enhanced bedplate block), component tuning (crankshaft/flywheel dynamics), and subsystem
Wang, Hao, Zhang, Guiqiang
Validation of an adaptive order Finite Element model for transmission loss simulation of trimmed automotive structures2026-01-0707To be published on 06/20/2026
Vehicle electrification and increasing demands for driving comfort present significant challenges for designing effective noise control treatments in modern vehicles. Lightweight, low-emission designs often compromise acoustic efficiency. One way of compensating this is through the use of multi-layer ‘trim’ material configurations to mitigate noise across a wider frequency range. Traditional 3D finite element models, while accurate and even needed to capture the full dynamic behaviour, become computationally prohibitive for complex automotive structures like firewalls, which feature intricate shapes, high curvature, and material compression. This computational burden limits design exploration and timely noise performance predictions. This paper introduces the use of an innovative adaptive higher-order finite element method to address these challenges. The method utilizes a fixed finite element discretization of trim components and surrounding acoustic fluid, incorporating an automated
Van Genechten, Bert, Vansant, Koen, Purohit, Bimal, Effinger, Veronika
A Self-Learning Framework for NVH CAE Analysis2026-01-0718To be published on 06/20/2026
The vibro-acoustic performance of a vehicle is a critical factor in customer perception of quality and comfort. Optimizing for Noise, Vibration, and Harshness (NVH), particularly road noise, presents a persistent challenge in the automotive development cycle. While modern FEM analysis is essential, the increasing complexity and sheer volume of CAE simulation data often overwhelm manual interpretation, potentially leading to prolonged development times or sacrifices in resulting comfort quality. To address these challenges, this paper introduces the application of CDH/ACE (Autonomous Computational Experiments), a framework that combines conventional CAE simulation workflows with machine learning in an iterative cyclic process. This creates a self-learning and self-correcting system that autonomously defines, performs, and learns from computational experiments. By building predictive models from simulation data, the framework intelligently guides the design exploration to achieve
Visser, Rene
NoiseSphere: An AI-Based Approach for Dynamic and Large-Scale Noise Mapping2026-01-0719To be published on 06/20/2026
Noise pollution is a major environmental and health challenge, yet its strong spatial and temporal variability makes comprehensive mapping highly complex. Current approaches under the European Noise Directive (END) provide only partial coverage and often lack temporal dynamics. The NoiseSphere project, fundet by the Austrian Research Promotion Agency FFG, develops an AI-based methodology for dynamic, large-scale noise prediction and mapping. A machine learning model is trained on heterogeneous data sources, including semantically enriched Sentinel-2 satellite imagery, OpenStreetMap road data, floating car data (traffic density and speed), and existing noise maps. The model is refined through integration of noise emission data and validated using targeted in-situ measurements. Two case studies, one located in an urban environment (Graz) and the other one in a rural region near Linz demonstrate the model’s applicability across contrasting settings. By combining remote sensing, traffic
Girstmair, Josef
Spatial Noise Acquisition at the Driver's Position in an Electric Vehicle with Increased Accuracy2026-01-0723To be published on 06/20/2026
In vehicles with electrified powertrains, high-frequency tonal noise components have become increasingly prominent and can be perceived as particularly annoying by the driver. While recent advancements in international standardization—such as ECMA-74 and ECMA-418—have led to powerful new algorithms for tonal noise visualization and analysis, like our Tonality-Heatmaps, the measurement side still lacks sensor setups that adequately reflect the spatial sensitivity of noise, especially for tonal components. This challenge is amplified in enclosed vehicle cabins, where room modes create local minima and maxima that become increasingly dense at higher frequencies. As a result, even small head movements can lead to noticeable differences in perceived tonal noise. Current measurement approaches do not sufficiently account for this spatial variability. This contribution addresses the absence of tailored solutions for the driver’s position by introducing an improved microphone arrangement that
Schecker, Daniel, Rittenschober, Thomas
Spatial Optimisation of Inner Dash Acoustic Performance using Reciprocal Holography2026-01-0712To be published on 06/20/2026
As acoustic requirements for NVH trim components become more demanding – driven by cost, weight, and increasingly, sustainability – there is growing pressure to optimise performance across multiple criteria. In complex components such as the inner dash, performance is often assessed in isolated. However, this fails to reflect real-world conditions, where contributions from ancillary systems, the instrument panel, and variable noise sources such as the power unit, gearbox, and tyres are significant. Traditional Transmission Loss (TL) measurements provide averaged results that can overlook spatial variation and lead to suboptimal design choices. To address this, an approach is presented that uses reciprocal holography to map the spatial TL performance of an inner dash. This method enables a more representative and targeted design process for achieving effective acoustic performance in fully built vehicle environments. Furthermore, the spatial Transmission Loss data can be combined with
Harry, Evan, Eandi, Giacomo
Effect of Backing PU Foam Material Properties on Acoustic Insulation Pad Insertion Loss2026-01-0678To be published on 06/20/2026
The effect of backing PU foam material on the insertion loss of insulation pads was investigated. First, the material properties affecting the resonant frequency—which determines the insertion loss—were theoretically identified, and practical methods for calculating both the resonant frequency and the insertion loss of the insulation pad were developed. These methods were then applied to evaluate how changes in material properties influence the resonant frequency and insertion loss of the insulation pad. It was found that Young's modulus, Poisson's ratio, and thermal characteristic length are the primary material properties that affect these outcomes. The optimal levels of these properties, which are beneficial for interior noise reduction, are derived and presented in this study.
Chae, Ki-Sang, Lee, Moonseok, Kim, Hyunwoo
Regularized Inverse Methods for Tire Noise Source Identification and Pass-by Noise Estimation in Electric Vehicles2026-01-0709To be published on 06/20/2026
Tire exterior noise has become increasingly critical in vehicle acoustics due to two key developments: updated pass-by noise regulations, which amplify the relative contribution of tire noise, and the rise of Battery Electric Vehicles (BEVs), which lack traditional powertrain noise. Design trends in BEVs—such as increased vehicle mass from battery packs and the widespread use of large-diameter, wide, low-profile tires—further intensify tire noise due to stiffer constructions and altered contact dynamics. A common method for predicting tire noise is the source-transfer-receiver model, where the tire is represented by a set of monopoles with volume velocity Q derived from near-field measurements. Acoustic propagation is modeled via p/Q transfer functions. Despite its simplifications, this approach is practical for vehicle development, enabling clear separation between source and transfer mechanisms and facilitating targeted noise control strategies. In previous work, we proposed a
Morin, Benjamin, Di Marco, Federico, Horak, Jan, Lafont, Thibault, Kim, Minkyu, Kang, Min Kyoo, Yoo, Ji Woo
Frequency Based Substructuring as Key Enabler for New NVH Root Cause Analysis Types in FE Simulations2026-01-0710To be published on 06/20/2026
Noise, vibration, and harshness (NVH) performance is critical in the automotive development process, yet identifying the true root causes of unwanted dynamic behavior remains a challenge in full vehicle or system‑level finite element (FEM) models. This work demonstrates how frequency based substructuring (FBS) provides an efficient framework for understanding NVH and facilitates new root cause analysis types and processes. To begin, we prove the high numerical accuracy of the FBS algorithm deployed in the BETA CAE software by comparing its results with those obtained without substructuring. Then we illustrate how FBS supports new root cause analysis types, starting with a new variant of transfer path analysis (TPA). While standard TPA assesses the paths between only two system components, the new expanding TPA is a multi-step process that identifies the most critical path across all components in a fully automated way. Furthermore, if the FBS workflow starts with a modal representation
Herbst, Markus
NVH Aspects of DC Charging2026-01-0703To be published on 06/20/2026
The deployment of high-power DC charging infrastructure for electric vehicles introduces new challenges in managing noise, particularly in public environments where acoustic comfort and regulatory compliance are essential. Noise emissions from both charging stations and vehicles during charging are a concern for operators of charging parks regarding customer experience and sound immission regulations. AVL employed a structured three-step approach to develop a non-expert tool for assessing the noise radiation of charging stations and vehicles during the charging phase. In a first step, AVL characterized the noise emissions with sound power measurements. Secondly, the measurement results were transferred to the virtual domain. To achieve this, the vehicles and charging station were characterized in the simulation with multiple monopole sources supported by transfer function measurements. This simulation model was validated against the sound power measurement results. After successful
Gojo, Josef, Polanz, Markus, Graf, Bernhard, Langjahr, Paco, Mehrgou, Mehdi
Automating Component NVH Characterization: A Systematic Approach for Component Test Bench Testing2026-01-0704To be published on 06/20/2026
The automotive industry faces increasing pressure as electrification introduces new components and accelerated development cycles shorten time-to-market, leaving limited opportunity to resolve Noise, Vibration, and Harshness (NVH) issues. This environment demands virtual development tools that are fast, precise, and efficient, and that can be seamlessly interchanged between development sites, suppliers, and OEMs; capabilities that are critical for effective target setting. Component-based Transfer Path Analysis (C-TPA), standardized in ISO 20270:2019, enables independent component characterization and integration with virtual models to predict sound and vibration in new assemblies, referred to as Virtual Prototype Assemblies (VPA). However, conventional measurements are labor-intensive and therefore typically restricted to a small number of samples, overlooking production variability. This paper introduces a system for fully automated, ISO 20270 compliant C-TPA on non-rigid test
Sturm, Michael, Wienen, Kevin, Brandstetter, Markus, Sorber, Eric, Corbeels, Patrick, Verrecas, Bart, Gonçalves, Vinícius
Field-Based Evaluation of Physiological Fatigue Reduction in Fuel Cell Refuse Collection Vehicle Using Heart Rate Variability2026-01-0690To be published on 06/20/2026
This study compared the physiological fatigue of drivers and accompanying workers operating diesel-powered (DI) and fuel cell-powered (FC) garbage compactor trucks under real-world working conditions. Reducing driver fatigue is critical for ensuring occupational safety and maintaining work efficiency, as fatigue in waste collection tasks is influenced by multiple factors such as vibration, noise, and vehicle operation characteristics. In this study, heart rate sensors and smartwatches were used to continuously monitor physiological responses during identical driving routes. Fatigue was evaluated using heart rate variability (HRV) indices—specifically, the root mean square of successive differences (RMSSD) and Lorenz plot (LP) area—calculated from RRI data. The results indicated that the RMSSD of drivers in FC trucks was approximately 60% higher and their LP area about 50% larger than those in diesel trucks. For accompanying workers, RMSSD was around 20% higher and LP area approximately
Utsumi, Atsuko, Yakoh, Takahiro
Electric drive unit housing ribbing for low noise radiation2026-01-0687To be published on 06/20/2026
Although propulsion noise often constitutes a minority of the overall noise in electric vehicles, it remains an important quality indicator due to its high-frequency tonal character, which is undesirable even at low levels. There are many factors that influence the interior car levels of propulsion noise, i.e. gear whine and electric motor whine. The primary ones to consider are the electric drive units (EDU) internal forces, but also secondary properties such as EDU housing design and encapsulation, vehicle sound pack and mount isolation play important roles. This work focuses on EDU housing design and more particularly on the housing ribbing that enables attachment point stiffness and housing strength, but which can also cause problems in terms of noise radiation. Numerical parameter studies on geometrical properties such as length dimensions, thickness and curvature were performed on single ribs of different types. For each design iteration, the key performance indicators radiated
Lennström, David, Malm, Oskar, wurzinger, Jakob, Cederlund, Johan
A High-Performance Computing Strategy for Acoustic Encapsulation Modeling of Electric Vehicle Subsystems Using Coupled BEM–PEM–FEM Methods2026-01-0694To be published on 06/20/2026
Electric vehicle subsystems, including powertrains, electric motors, and gearboxes, pose new challenges in achieving stringent acoustic performance targets for both interior and exterior noise. These challenges are intensified by increasingly demanding customer expectations regarding interior acoustic comfort, which encompasses the reduction of intrusive noise sources and the enhancement of overall sound quality across a broad frequency spectrum. A primary concern associated with electric vehicles subsystems is the generation of high-frequency tonal noise, commonly referred to as whine noise, which can significantly impact acoustic performance and passenger comfort. High-frequency whine noise propagates through multiple transmission paths and can be effectively attenuated at the source through encapsulation strategies, which also contribute to broadband noise reduction across a wide frequency spectrum. To predict the acoustic performance of encapsulation, a coupled simulation approach
Amichi, Kamel, Calloni, Massimiliano
Bridging Simulation And Reality: Incorporating Seal Contact Detachment Into Stick–Slip Prediction2026-01-0714To be published on 06/20/2026
Preventing stick–slip in virtual vehicle development combines virtual displacement data with experimental sliding tests. If the calculated relative displacement at a contact exceeds the distance of two stick–slip impulses, that contact could be a potential noise source. Such risks can be mitigated only by design changes or alternative sealing concepts. Stick–slip tests provide the experimental reference, showing how often a frictional pairing produces impulses over a defined sliding distance. The basis for this assessment is Multibody Dynamics (MBD) simulations, which compute component deformations during virtual drives and derive relative displacements at contact interfaces (e.g. in the sealing gap between body and closure), representing the theoretical sliding distance that enables stick–slip effects. Yet, this combined approach has overlooked a critical factor: the deformability of automotive seals. Due to their elastomeric properties and geometry, seals can elastically follow
Strangfeld, Martin, Fritz, Susanne, Weber, Jens, Rosell, Anneli
Single microphone sound source localisation in partially known environments using sequential spatial sampling2026-01-0681To be published on 06/20/2026
Sound source localization is a fundamental capability for environmental awareness in a wide range of applications, including automotive or automated vehicles. Microphone-array-based signal processing techniques are widely used for this task. However, achieving sufficient localization accuracy often requires a large number of microphones and wide array apertures, which can be incompatible with limited installation space and cost constraints. Moreover, standard array-processing methods often rely on free-field transfer functions. In environments with reflections, diffraction, and scattering, particularly under non-line-of-sight conditions, this mismatch can degrade both accuracy and interpretability. This paper presents a methodology for sound source localization in partially known environments that addresses these challenges by combining two ideas. First, the method reduces sensor requirements by exploiting sequential pressure measurements acquired at different spatial locations along a
Pirro, Giovanni Battista, Nijman, Eugene, Deckers, Elke, Denayer, Hervé
Study on Interior Noise Contribution and Improvement Measures for the Door System of a Premium Vehicle2026-01-0675To be published on 06/20/2026
It has been observed that in recently developed advanced vehicles, the door system contributes significantly to interior noise levels. In this study, the noise transmission paths through the door system were investigated and effective improvement measures were explored. In order to determine the noise transmission paths through the door system and to establish effective countermeasures, door buck tests were conducted. In addition, under the same conditions, simulations were carried out using a Finite Element-based acoustic analysis tool to evaluate the effectiveness of modifications that could not be tested experimentally. While attaching sound-absorbing pads to the rear surfaces of door trims is a commonly used method for improving noise transmission, the most effective approach was found to be the addition of sound-absorbing materials between the door outer panel and the module panel, as well as reducing the vibration of the door outer panel itself.
Chae, Ki-Sang, Jang, Jinung, Jeong, Hojung, Do, Hyuncheol, Han, Jinwoo, Yi, Jaebok, Bak, Seong-Jae, Jeong, ChanHee
The Influence of Interior Noise on Just-Noticeable Speed Differences in Conventional and Electric Vehicles2026-01-0671To be published on 06/20/2026
Electric vehicles (EVs) and internal-combustion-engine vehicles (ICEVs) differ fundamentally in their in-cabin acoustics, notably the attenuation or absence of engine-order content. Prior work reports associations between reduced engine sound, speed underestimation, and poorer speed maintenance; however, research on how EVs’ new sound affects speed perception and control is scarce, and most newer studies focus on comfort and subjective pleasantness rather than speed perception per se. Addressing this gap, the present study uses a two-interval, two-alternative forced-choice (2AFC) paradigm to directly measure just-noticeable differences (JNDs) in speed under ICEV, EV, and silent conditions. Thirty participants performed a 2AFC task in which, on each trial, they viewed two first-person highway clips (reference vs. comparison) and indicated which appeared faster. Results from ANOVA and post-hoc tests indicate that at the 40 km/h reference speed participants showed no clear differences
Li, Zhenxian, Parizet, Etienne, Colangeli, Claudio
Holistic sound package design for optimal NVH and carbon footprint of a BEV2026-01-0708To be published on 06/20/2026
Vehicle sound packages are usually designed to provide a given level of vehicle NVH comfort, under weight and cost constraints. Optimal comfort results can be obtained by considering the interaction of all the parts as a full physical system. So far, extensive research has already been performed and published on optimizing vehicle sound packages to achieve effective noise reduction at lowest cost and weight. Nowadays, due to the urgency of the transition to carbon neutrality, sound packages must also address the reduction of the full vehicle life cycle carbon emissions. Sound package components should use materials that have a low emission impact during production and that are suitable for recycling at the end of the vehicle’s life. This entails reconsidering the material solutions chosen for the sound package as a whole, rather than for each individual component. This article describes the design process of a sound package involving NVH, sustainability, and weight/cost requirements
Courtois, Theophane, Cardillo, Marco, Criscione, Mattia, Gerges, Youssef, Massocco, Andrea
Towards Realistic Stick-Slip Testing: Efficiently Mapping Material Behaviour across a wide Range of Loading Conditions2026-01-0713To be published on 06/20/2026
To minimise noise caused by interior components rubbing against each other, automotive materials are usually tested in advance with the established stick-slip method according to VDA standard 230-206. This procedure is widely used for soft materials, upholstery and plastics. However, it is limited to constant climatic and selected loading conditions. Contrary, in real application, changing climates and dynamic excitations can nevertheless trigger noise issues even in materials rated as suitable in the prior tests. To address this gap, a new test method has been developed that evaluates the stick-slip behaviour of material combinations for a wide range of loading and climatic conditions. Conducted in a climate chamber with a standard stick-slip bench, the procedure applies sinusoidal excitations, dynamic climatic shifts and advanced data analysis. In addition to the usual results the new method also evaluates realistic scenarios such as starting a vehicle in different seasons or sudden
Fritz, Susanne, Strangfeld, Martin
Design of Acoustical Features for a Quitter Aero-Engine Test Facility2026-26-0787To be published on 06/01/2026
It is a general practice to test aero engines to evaluate their performance in specially designed indoor test facilities after assembly, repaired or overhaul. Acoustic features are provided in the test facility to attenuate the noise level to a comfortable and acceptable level. Design of these features specially air intake and exhaust silencers are a challenging task in a flow field like aero-engine test facility considering the very high sound pressure level generated by them during test containing a very wide frequency band. Moreover, growing population and location of these facilities in the vicinity of residential areas has added this challenge in multifold. Also, the capital investment in building these facilities is huge due to their large size and longer construction time. Hence, the correct execution at first shot including design, fabrication and commissioning is very important. An attempt has been made to reduce design errors or improve the accuracy in the design stage by
Gouda, Bansidhar
Impact Study of Terrestrial Jamming on GNSS Receiver On-Board Launch Vehicles and Mitigation Technique Using RF Switch2026-26-0766To be published on 06/01/2026
Global Navigation Satellite System (GNSS) receivers are widely being used in aerospace as well as automotive applications primarily for navigation applications. ISRO uses indigenously developed GNSS receivers in its Launch vehicles (LV) mainly for POD (Preliminary Orbit Determination) and for INS aiding in long duration missions. Advanced GNSS receivers are being developed and used in ISRO’s new generation launch vehicles for closed loop guidance (CLG) applications. Being used in CLG, continuous solution availability and robustness of GNSS solutions are of paramount importance. From April 2023 onwards, GNSS receivers on-board ISRO’s LV missions have shown degraded performance in terms of reduction in no. of satellites tracked and in some cases loss of GNSS solution as well. This was seen in multiple missions and was analyzed in detail. It was observed that there is nearly 3-4dB reduction in carrier to noise density (C/No) ratio and corresponding change in RF AGC gain is also observed
A, Mohammed Basim, O T, Anand Shankara, V S, Biju, V Gopal, Biju, V S, Vinoj, K, Balan, C, Radhakrishna Pillai
Multi-Objective Parameters Optimization of Centrifugal Fan Based on GA-BP Neural Network and NSGA- II2026-99-07015/15/2026
In order to achieve the research objective of simultaneously improving the air volume and reducing the noise of centrifugal fans, a combination of orthogonal experimental design, BP neural network modelling and multi-objective genetic algorithm (NSGA- II) was used to find the optimal method, and the worm tongue placement angle φ, worm tongue radius R, expansion angle θ and outlet expansion section height L of the worm casing were selected as optimization variables. The air volume and noise of the centrifugal fan under the design working condition were calculated by non-constant and constant calculations, and the air volume and noise were used as the optimization objectives. The results demonstrate that, compared to the initial design, the optimized fan model achieved a noise reduction of 10.99 dB and an airflow increase of 1.76%. Furthermore, the amplitude of the pressure pulsation coefficient at the blade passing frequency was significantly reduced at the monitoring point near the
Huang, Guoxing, Zhang, Weihong, Li, Weichang
Time Series Causal Discovery Based on Data Augmentation and Causal Validation2026-99-07035/15/2026
Causal discovery within time series is crucial for revealing the actual causal mechanisms in dynamic systems, and it has major impacts in various fields like economics, healthcare, and climate science. Even though it’s important, accurately figuring out causal relationships from observational temporal data is still quite a difficult task. Traditional Granger causality based methods are often limited by noise sensitivity, large amount of data, and the inability to distinguish between real causality and false correlation caused by hidden factors. In order to solve these problems, this paper presents CausalAugVeri, which is a new algorithm that cleverly mixes data augmentation with causal verification to make causal discovery more solid and precise. This work has three main points: First, we carefully check that using convolutional data augmentation techniques can greatly improve how well time series predictions work, giving a steadier base for detecting Granger causality. Second, the
Yang, Jing, Chen, Xiaotao, Qin, Xuanli, Xu, Xianjun, Hu, Zhangxiang
Battery Cooling System Airborne Noise Correlation Using Statistical Based14-15-02-00084/16/2026
In a traditional electric vehicle, managing its battery thermal performance is of prime importance. A well-designed battery thermal management system helps in extending its life and avoids safety-related issues like thermal runaways. A critical part of this thermal management is the battery cooling system (BCS), which can be air- or liquid-cooled. Based on the vehicle battery pack size, location, and its design complexity, the original equipment manufacturer can opt for either of the previous two methods. An air-cooled type of BCS system usually involves an active ventilation fan to dissipate the battery heat in the surroundings, which brings symbiotic noise into the picture. In an air-cooled BCS system, the primary source of noise is the cooling airflow over the heat exchanger caused by the fan. The airflow and noise performance characteristics of this fan are typically measured by the supplier in a standalone condition. These performance parameters deviate greatly when the fan is
Nomani, Mustafa, Dupatti, Darshan, Nikam, Krishna, Sasikumar, R., Kajagar, Suresh, Panchare, Dattaji, Agalawe, Kiran
Dog Clutch Actuator Control to Mitigate NVH2026-01-00034/7/2026
Dog clutches have long been employed in the automotive industry across various applications, including transmission systems, transfer cases, axle disconnects, and hybrid driveline architectures. Their ability to provide direct mechanical engagement makes it ideal for torque transmission with minimal energy loss. However, the transition between engaged and disengaged states can introduce noise, vibration, and harshness (NVH), which may be perceptible to vehicle occupants and affect overall driving comfort. A typical dog clutch relies on interlocking teeth for torque transfer, and its actuation can result in NVH due to factors such as friction between mating surfaces, backlash between engagement components, teeth-on-teeth contact during synchronization, and impact forces during clutch engagement. This paper presents Stellantis’s approach to controlling the actuator system to mitigate NVH effects during clutch engagement and disengagement, focusing on strategies that enhance drivability
Xu, Chengyi, Madireddy, Krishna Chaitanya, Verhun, Brandon
Acoustic Improvements to a Passenger Service Unit Panel with Core Filler and Facesheet Patches using Topology Optimization2026-01-05114/7/2026
Passenger comfort is becoming the forefront of luxury private jets where noise needs to be kept to a minimum. One source of structure-borne noise is the vibration of the Passenger Service Unit (PSU) panel. These vibrations originate from the outer skin, excited by turbulent boundary layer, and are transmitted through the fuselage frame to the PSU panel. This panel resides overhead of passenger seating, it is composed of a corrugated honeycomb core sandwiched between thin face-sheets. This paper presents a systematic approach to improve the vibro-acoustic performance of a honeycomb core sandwich structure by employing core filler and facesheet patches. Topology Optimization (TO) is used to determine the optimal layouts of these design modifications. The vibro-acoustic performance of the PSU panel with facesheet patches and core filler is evaluated using a frequency response analysis in the commercial finite element solver OptiStruct. The effectiveness of vibration reduction will be
Russo, Connor, Whetstone, Isobel, Patel, Anuj, Wotten, Erik, Kim, Il Yong
Machine Learning-Based Prediction of Wind-Induced Interior Noise in Ground Vehicles2026-01-05994/7/2026
In response to increasing customer demand for enhanced passenger comfort and perceived vehicle quality, OEMs in automotive and commercial vehicles are placing significant emphasis on reducing the interior cabin noise. At highway speeds, wind noise is a primary contributor to the overall noise within the vehicle cabin. Conventional approaches to predict vehicle wind noise rely on physical testing, which can only be conducted in the later stages of the design process once a physical prototype is available. Increased adoption of established computational fluid dynamics (CFD) methods has enabled earlier assessment. However, such simulations require several hours to complete, posing a challenge in the context of rapid design iteration cycles. With the growing adoption of artificial intelligence in engineering, machine learning (ML) approaches have been proposed to predict a vehicle’s aerodynamics performance. Nevertheless, development of ML techniques in the context of aeroacoustics
Higgins, John, Fougere, Nicolas, Sondak, David, Senthooran, Sivapalan, Moron, Philippe, Jantzen, Andreas, Bi, Jing, Oancea, Victor
Self-Supervised Gaussian-Based Framework for Robust Static-Dynamic Decomposition and Real-Time Urban Scene Reconstruction2026-01-00104/7/2026
High-fidelity 3D reconstruction of large-scale urban scenes is critical for autonomous driving perception and simulation. Existing neural rendering methods, including NeRF and Gaussian-based variants, often face challenges like unstable geometry, noisy motion segmentation, and poor performance under sparse viewpoints or varying illumination. This paper presents a self-supervised Gaussian-based framework to address these challenges, enabling robust static–dynamic decomposition and real-time scene reconstruction. The proposed method introduces three innovations: (1) a semantic–geometric feature fusion module that combines semantic context and geometric cues for reliable motion prior estimation; (2) a cross-sequence geometric consistency constraint that enforces depth and surface continuity across time and viewpoints; (3) an efficient Gaussian parameter optimization strategy that stabilizes geometry by jointly constraining scale and normal updates. Experiments on the Waymo Open Dataset
Feng, Runlei, Wang, Ning, Zhang, Zhihao
The Stellantis North America Aero-Acoustic Wind Tunnel Upgrade2026-01-06094/7/2026
The Stellantis North America Aero-Acoustic Wind Tunnel (AAWT) has been upgraded with a cutting-edge 5-belt Moving Ground Plane (MGP) system, featuring an 8.5-meter center belt and four Wheel Spinning Unit (WSU) belts with advanced coatings for durability and visibility. The expanded 9.4-meter turntable enables ±90° yaw and supports vehicles with wheelbases from 1800 mm to 4500 mm and weights up to 5000 kg, accommodating the full Stellantis North America product range. The original 2-stage boundary layer control system was retained, with new tertiary slots added for improved flow quality. A high-stiffness, six-component Horiba balance with integrated calibration weights and tractive force measurement ensures accurate and precise measurements. Facility enhancements include a 550 m2 building addition for equipment and vehicle prep, a dedicated compressor container for clean air supply, and a vehicle underbody wash booth for efficient cleaning. Commissioning confirmed that flow quality
Lounsberry, Todd, Ladouceur, Brent, Fadler, Gregory
Simulation based Prediction and Optimization of Acoustic Comfort in Vehicle Interiors2026-01-05024/7/2026
Passenger expectations for quiet and acoustically comfortable vehicle interiors have increased significantly, driven by advancements in electric vehicles and premium audio systems. Acoustic comfort affects perceived quality, communication ease, and overall driving experience. This paper presents a simulation-driven methodology to predict and optimize interior noise performance during the early design phase, focusing on high-frequency acoustic transfer functions and trim material absorption properties. Traditional NVH development relies heavily on physical testing, which is time-consuming and costly. Early-stage predictive tools are essential to evaluate acoustic performance before prototype availability. High-frequency noise (1kHz–12kHz) is particularly challenging due to complex reflections and absorption behavior. Acoustic trims play a critical role in shaping the cabin’s sound field, and their properties must be optimized to achieve desired sound quality. A novel simulation approach
Baladhandapani, Dhanasekar, Jadhav, Vishal, Du, Isaac
Elucidation of Flow Mechanisms Modulating Vehicle Wind Noise by Using Large-Scale CFD Simulation2026-01-06144/7/2026
In vehicle development, noise reduction is critical for ensuring passenger comfort. As electric vehicles become prevalent and engine noise is minimized, wind noise becomes more noticeable. Modulated wind noise, which causes a sense of fluctuation due to atmospheric turbulence, wind gusts, and preceding vehicle wakes, can cause significant discomfort. This noise is characterized as a high frequency sound above 1 kHz, modulated at low frequencies owing to the wind velocity and direction fluctuating at several Hz. The mechanisms behind wind noise modulation are not fully understood, and no established countermeasures have been developed. This is because wind noise perceived through the side window is primarily caused by the A-pillar vortex and door mirror wake, which coexist as complex turbulent flows around the vehicle. Therefore, identifying the source of modulated wind noise around vehicles under fluctuating wind conditions is difficult. This study aims to identify the source of the
Tajima, Atsushi, Hirata, Takumi, Ikeda, Jun, Kamiwaki, Takahiro, Wakamatsu, Junichi, Tsubokura, Makoto
Swept Collector Design for the HALO Wind Tunnel2026-01-06084/7/2026
Modern aeroacoustic wind tunnels are required to have flat axial static pressure distribution, very low background noise levels, and minimal low-frequency pressure fluctuations. These characteristics enable accurate measurement of aerodynamic forces acting on a vehicle as well as identification of noise sources. The collector of an open-jet or ¾ open-jet wind tunnel plays a critical role in achieving these goals. Collector self-generated noise contributes to the overall background noise level in the test section, and this contribution has become more significant as other noise sources, such as the main fan, have been addressed through improvements to acoustic treatment. Ever-increasing attention to detail is required to manage noise signatures as the overall facility noise floor is lowered. Furthermore, aspects of collector design that may be beneficial to aerodynamics or pressure fluctuation tend to be some of the worst offenders for noise generation. A new collector configuration was
Best, Scott, Nagle, Paul
Enhancing LiDAR Performance under Fog with Adaptive Multi-Echo and Feature-Based Filtering2026-01-00114/7/2026
LiDAR (Light Detection and Ranging) systems are essential for autonomous driving (AD) and advanced driver-assistance systems (ADAS), providing accurate 3D perception of the surrounding environment. However, their performance significantly deteriorates under adverse weather conditions such as fog, where laser pulses are scattered by airborne particles, resulting in substantial noise and reduced ranging accuracy. This scattering effect makes it difficult to detect objects within or behind particulate matter, posing a serious challenge for reliable perception in real-world driving scenarios. To address this issue, we propose an algorithm that combines adaptive multi-echo signal processing with a feature-integrated, rule-based denoising framework to enhance LiDAR performance in noisy environments. The multi-echo approach selectively utilizes meaningful signal returns by evaluating both intensity and relative echo positions. Based on predefined rules, the algorithm identifies the echo most
Kaito, Seiya, Zheng, Shengchao, Fujioka, Ibuki, Beppu, Taro
Lightweight Bubble Sheet Panel To Reduce Inverter Noise and Vibration for Electric Vehicles2026-01-04424/7/2026
Inverters are typically integrated into electric drive units for electric vehicles (EVs) to reduce packaging size and cost. However, coupled vibrations from the electric motor and gears are transmitted to the inverter, which can become a dominant noise source due to its large radiative panel. Metal panels are required for electromagnetic interference (EMI) compliance, yet these covers usually lack sufficient stiffness or damping for noise control. Adding ribs and applying damping treatments result in excessive mass, cost, and packaging challenges. A new bubble sheet panel design has been developed to enhance the structural strength and damping performance of the inverter cover while significantly reducing its mass. A thin sheet of aluminum is welded onto the cover in an optimized pattern that enhances stiffness and damping performance while accommodating packaging requirements. The welding pattern can include logos or artistic designs to improve the panel’s appearance. The metal sheets
He, Song, Bobel, Andrew, Naismith, Gregory, Yi, Wenwen, Patruni, Pavan Kumar
Predicting Electric Vehicle Interior Noise Quality from Drive Unit End-of-Line Vibration Testing2026-01-02234/7/2026
The Noise, Vibration, and Harshness (NVH) quality of electric vehicles (EVs) is heavily influenced by the performance of the electric drive unit. As a critical step in production, End-of-Line (EOL) testing of drive units is used to assess and control component-level NVH before vehicle assembly. However, the correlation between EOL test results and final vehicle interior noise quality, which directly impacts customer satisfaction, is not always fully understood. This paper presents a methodology for characterizing and predicting vehicle interior noise quality based on data from drive unit EOL vibration testing. Our study investigates the intricate relationship between drive unit assembly variations, component tolerances, and the resulting vibration response. We establish a robust correlation between these drive unit characteristics and both objective vehicle interior noise levels and subjective customer perception. The findings provide a framework for using EOL data to proactively
Arvanitis, Anastasios, Jangid, Kuldeep
Machine Learning-Based Gear Defect Detection in Electric Vehicle Drive Units Using End-of-Line Vibration Analysis2026-01-06374/7/2026
The final assembly of electric vehicle (EV) drive units includes an essential End-of-Line (EOL) test to ensure both component integrity and Noise, Vibration, and Harshness (NVH) quality. This screening process, which uses dynamometers to measure vibration signals, is critical for identifying defects before a drive unit is installed in a vehicle. A significant source of failure during this test is gear defects, which can arise from manufacturing or handling issues. Traditional EOL testing methods rely on time-domain analysis and the impulsiveness of vibration signatures to detect these defects, a technique with inherent limitations in accuracy. This paper introduces and evaluates a novel approach using Machine Learning (ML) to analyze vibration signals for improved gear defect detection. We discuss the methodologies of both the traditional time-domain and the proposed ML-based techniques. Finally, we provide a comprehensive comparison of their respective efficiency and accuracy
Arvanitis, Anastasios, Michaloliakos, Anargyros
An Image-Derived Multimodal Framework for Automotive Tire Exterior Noise Prediction2026-01-02204/7/2026
This study presents an image-derived multimodal AI framework for early-stage tire noise evaluation. The proposed model requires only multi-angle photographs captured by a standard smartphone and basic tire specifications. From these images, scaled three-dimensional (3D) meshes and fixed-view depth maps are reconstructed and combined with numerical parameters within a neural network architecture. Three input branches—a point-cloud–gradient branch, a depth-map convolutional neural network (CNN) branch, and a specification multi-layer perceptron (MLP) branch—are jointly trained using a composite loss that integrates frequency-weighted mean squared error (MSE), spectral cosine similarity, FFT-domain consistency, and A-weighted sound-level terms. A dataset of 28 tires, spanning passenger, SUV, and pickup applications for both battery electric vehicles (BEVs) and internal combustion engine (ICE) vehicles, was evaluated using leave-one-out (LOO) cross-validation. The model achieved a mean
Shao, Guangxin, Shopoff, Scott, Franklin, Nicholas
A System-Level Calibration Framework for Embedded Vision: Integration of Sensor, Firmware, and Software Enhancements2026-01-00134/7/2026
Embedded vision systems are essential for contemporary applications, including robotics, advanced driver assistance systems (ADAS), and intelligent surveillance; yet they frequently experience diminished image quality due to resource constraints, environmental variability, and inconsistent illumination conditions. Such degradations impact multiple visual attributes—sharpness, contrast, color accuracy, noise levels, and structural similarity—that are critical for reliable perception in safety- and performance-driven domains. This study introduces a comprehensive system-level calibration architecture that integrates three coordinated layers: sensor-level adjustment, firmware optimization, and adaptive software enhancements. At the sensor level, exposure control, gain tuning, and white balance adjustments mitigate luminance imbalance and color shifts under changing light conditions. Firmware optimization leverages image signal processor (ISP) parameters to reduce temporal and spatial
Indrakanti, Rama Kiran Kumar, Vishnoi, Nitin, Kamadi, Venkata
Acoustic Simulation for a Vehicle Audio System Across the Full Audible Frequency2026-01-02264/7/2026
The Audio system is an important part of the design of a vehicle cabin. In the vehicle development process, the audio system needs to be tuned for optimal acoustic performance. Traditionally, this process is performed physically on vehicles. In this paper, a methodology is developed to numerically simulate the acoustic performance of the audio system across the full audible frequency range. To provide validation of the method, the p/v acoustic transfer functions (ie., the sound pressure p at the passengers’ ears divided by the voltage inputs v) are measured for different speakers in a production vehicle. As the sound perceived by the passengers depends on both the source and the path, the method development is split into two parts: (a) characterization of parameters that describe the loudspeaker as a source and (b) representation of the vehicle cabin as a path. The speaker parameters are characterized from sound radiation data measured in a 2pi chamber. To represent the vehicle cabin
Yang, Wenlong, Patra, Suresh, Hawes, David, Shorter, Phil
NVH Characterization of New Pulse Width Modulation Strategies2026-01-02244/7/2026
Pulse Width Modulation (PWM) is needed to supply AC motors from DC voltages, but it creates high-frequency sideband harmonics that contribute negatively to sound quality. Several strategies were developed in the last decades to reduce the total harmonic distortion and switching losses, including discontinuous PWM. A new formulation of discontinuous PWM waveforms is proposed. It eases the implementation of PWM in simulation models and on experimental platforms, but it also enables the creation of new strategies. This study aims at assessing the NVH performance of six new strategies proposed by the authors. The goal is not to enhance the electrical performance but to seek new sound attributes, to change the sound quality of the machine. All strategies were tested on a test bench to characterize their current, vibration, and noise level on the full modulation index range. The measurements performed with the new strategies present some contrast. Semi-discontinuous strategies, which present
Wanty, Salomé, Delpoux, Romain, Glesser, Martin, Totaro, Nicolas, Parizet, Etienne, Degrendele, Karine
Predictive Assessment of Drum Brake Squeal Utilizing Advanced Time-Domain CAE Synthesis2026-01-02214/7/2026
With the growing trend of electric vehicles (EVs) incorporating regenerative braking systems, many compact SUVs, including hybrids and EVs, still utilize drum brakes on the rear wheels to strike a balance between cost, performance, and durability. Drum brake squeal remains a complex and persistent challenge in the field of vehicle noise, vibration, and harshness (NVH). This issue stems from dynamic instability caused by time–dependent friction forces. Traditional linear modal analysis has been used to study the mechanisms behind drum brake squeal, focusing on harmonic vibrations in large–scale models. However, these methods often fail to accurately correlate with real world behavior due to the presence of extra, non-physical modes. To address this, time–domain analysis approaches have been explored, incorporating detailed friction models and contact mechanics. These methods consider different root causes for high and low–frequency squeal and have shown promising results in accurately
Song, Gavin, Kazimierczyk, Stanislaus, Vlademar, Michael, Venugopal, Narayana
The Study on Alternative Switching Noise Caused by Pulsating Magnetic Field Off Direct Current Ripple Induced by the Invertor Switching2026-01-50223/30/2026
As already well-understood/enormous engineering practices, the inverter AC-side NVH phenomena/mechanisms/measures for motor-equipped vehicle, are already pretty clear. In addition to inverter AC side–induced NVH issues, DC ripple induced by PE switching leads to NVH issues manifesting on the capacitor, inductor, and conductor in terms of reverse piezoelectricity, electrostriction, magnetostriction, Laplace force, and so forth. These DC-side NVH issues are already literally analyzed by a couple of literatures, and mechanisms/measures are explored/applied to electric drive development. And yet, the phenomenon that a pulsating magnetic field inside a battery pack induced by DC current ripple off PE switching brings noise at switching frequency inside the vehicle cabin is newly captured/analyzed by our research, and that has been barely searched during the literature survey. This newly discovered phenomenon is the pivotal point in this paper. Although the noise features like the
Zhao, Qian, Zhao, Yihan, Niu, Haolong, Li, Qiwei, Zhang, Wenchao, Xue, Hongbin, Cheng, Yanan, Li, Jing, Kang, Ming
Analyzing Effects of Cell to Chassis Technology on Sound Transmission Loss of Skateboard- Sharing Vehicles2026-01-50243/30/2026
Limited published research has critically examined the impact of Cell-to-Chassis (CTC) structures on the Noise, Vibration, and Harshness (NVH) performance of electric vehicles (EVs), with most studies focusing on conventional Cell-to-Pack (CTP) systems. A concern is that vehicles employing CTC architectures may exhibit compromised NVH performance due to the absence of a dedicated floor panel. To investigate the NVH performance implications of the CTC structure, this study adopts a comprehensive methodology encompassing: (1) theoretical Sound Transmission Loss (STL) analysis utilizing mass law and double-panel principles, (2) finite element (FE) modeling of STL, (3) in-vehicle Acoustic Transfer Function (ATF) testing, and (4) interior noise measurements conducted at a constant 60 km/h on a smooth asphalt road. Simulation results demonstrate that, compared to a conventional CTP floor system, the studied CTC structure achieves a 5–40 dB increase in STL across the 200–2000 Hz frequency
Xu, Xueying, Wang, Xiaoming, Ma, Caijun, Li, Guofu
Development of BYD Flat Engine for Luxury Hybrid Vehicles03-19-02-00072/24/2026
To meet the requirements of luxury hybrid vehicles regarding engine power, torque, size, and NVH performance, BYD independently developed a 2.0 T flat engine. Designs such as increased intake valve lift, widened intake valve profile, swept piston bowl, and extended exhaust backflow region optimized in-cylinder airflow, enabling the BYD flat engine to achieve a maximum power of 180 kW and a peak torque of 380 N·m. This engine is 820 mm in length, 430 mm in width, and 420 mm in height, saving approximately 45% in volume compared to a competitor engine. The lubrication challenges of the flat engine were addressed through the coordinated implementation of a dry sump system, a multifunctional oil pump, and piston ring orientation design. A novel parameterized modal analysis methodology (considering phase and amplitude) was used for optimizing NVH performance. In synergy with the sandwich-type soundproof plates and four-sided acoustic encapsulation, the noise level (1-m sound pressure level
Pan, Shiyi, Zhang, Nan, Wang, Qiang, Liu, Jun, Liu, Jing, Xu, Zhiqin, Zheng, Junli, Li , Cunshuo
Experimental Vibroacoustic Measurement of Thin Steel Panels Coated with Different Liquid-Applied Spray Damping Layer Thickness10-10-02-00172/23/2026
This study investigates the effect of liquid-applied spray damping (LASD) thickness on the vibration and sound radiation of thin steel panels. Although LASD is widely used to enhance structural damping, its influence on radiated sound and the role of coating thickness have not been systematically studied. Five steel panels with varying LASD thicknesses were evaluated using two experimental approaches. An impact-based method in a hemi-anechoic chamber measured the structural mobility and noise transfer functions, while a reciprocal method in a reverberation chamber under acoustic excitation measured the radiated sound power transfer function. A thickness ratio was found beyond which additional LASD thickness yielded diminishing improvements in noise and vibration reductions. The effect of LASD thickness on radiation efficiency was also assessed in both narrowband and one-third octave bands.
Neihguk, David, Suh, Sam, Herrin, David W.
Optimized Design, Analysis, and Validation of a Tractor Muffler for Enhanced Back-Pressure Control and Cost Efficiency2026-28-00042/12/2026
Internal combustion engines generate intense acoustic pulses during combustion, necessitating the use of exhaust mufflers to suppress noise emissions. With evolving regulations on permissible noise levels and the automotive industry's drive toward lightweight, high-performance vehicles, muffler designs must balance effective sound attenuation, minimal back pressure, and reduced mass. This study presents a comparative analysis of three muffler configurations serpentine, rectangular, and zigzag designed using Solid Works for a light commercial vehicle (LCV) diesel engine. The models were evaluated using computational fluid dynamics (CFD) simulations to assess their acoustic and flow performance. Each design incorporated internal baffle arrangements to enhance sound absorption while aiming to minimize back pressure. The serpentine model featured a perforated baffle layout that promoted multiple reflections and dissipated acoustic energy more efficiently. Simulation results indicated that
Deepan Kumar, Sadhasivam, Palaniselvam, Senthil Kumar, D, Ashokkumar, R, Krishnamoorthy, Mahendran, M, Pasupuleti, Thejasree, G, Dhayanithi, L, Boopalan
An Integrated Model Approach for Predicting Vehicle Dynamics Performance in HiL Validation2026-28-00442/12/2026
In the automotive industry, increasing noise regulations are influencing product sales and passenger comfort, creating a need for more effective noise testing methods. Hardware-in-Loop (HiL) based virtual acoustic testing serves as a critical step before Driver-in-Loop testing, allowing for the assessment of vehicle performance and noise levels inside and outside the vehicle under various conditions before physical prototype testing is performed. The Hardware-in-the-Loop (HiL) simulator setup is equipped with joystick control that requires a physical representation of the vehicle dynamics model provided as a Functional Mock-up Unit (FMU) in real-time format. In contrast, the vehicle control logic is implemented in C++ code. The simulator incorporates both lateral and longitudinal dynamics. Additional interfaces are integrated to support joystick input and virtual road visualization enabling realistic vehicle maneuvering and dynamic performance evaluation. However, performing all test
Visuvamithiran, Rishikesan, Chougule, Sourabh, Srinivasan, Rangarajan, Laurent, Nicolas
Sound Quality Refinement and Vibration Reduction During Horn Application in Electric Vehicles2026-26-03381/16/2026
This paper focuses on the cabin sound quality refinement and the tactile vibration reduction during horn application in the electric vehicle. A loud cracking sound inside the cabin and higher accelerator pedal vibration are perceived while operating the horn. Sound diagnosis is carried out to find out the frequencies causing the cracking noise. Transfer path analysis is conducted to identify the nature of noise and the predominant path through which forces transfer. Based on finding from TPA, various recommendations are evaluated which reduced the noise to a certain extent. Operational Deflection Shape (ODS) is conducted on the horn mounting bracket and on the body to identify the component having higher deflection at the identified frequencies. Recommendations like DPDS improvement on the horn bracket and the body is assessed and the effect of each outcome is discussed. With all the recommendations proposed, the cabin noise levels are reduced by ~ 8 dB (A) and the accelerator pedal
S, Nataraja Moorthy, Rao, Manchi, R, Ashwin sathya, S, THARAKESWARULU, Raghavendran, Prasath
Items per page:
1 – 50 of 6217