Browse Topic: Noise, Vibration, and Harshness (NVH)

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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
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
Feasibility of Hybrid Dynamic Substructuring for Structural Modifications in Automotive Suspension Subsystems2026-01-0697To be published on 06/20/2026
Recent advancements in system-level NVH (Noise, Vibration, and Harshness) development methodologies have improved target cascading and enabled more efficient system-level optimization. Dynamic substructuring facilitates the virtual integration and modification of multiple subsystems and the prediction of changes in overall transfer functions. In practical automotive applications, advanced frequency-based substructuring has been applied to virtually modify system parameters—such as mass and stiffness—at multiple points in a target system, allowing prediction of the resulting effects and optimization of parameter changes without physical intervention. This study extends the methodology by introducing an enhanced substructuring approach capable of addressing not only basic parameter modifications but also large-scale structural changes. The proposed process involves identifying the characteristics of a base system assembly and a target subsystem, decoupling the subsystem from the assembly
Cho, Munhwan, Boelens, Jelle, Reichart, Ron, de Klerk, Dennis, Ahn, Jiho
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
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
Simulation and Analysis of Flow and Acoustic Induced Structural Vibration2026-01-0696To be published on 06/20/2026
For analysing flow and acoustic induced structural vibration, a run time fully coupled framework combining a hybrid CFD-CAA approach with a modal response simulation was validated and presented at the ISVNH 2022 (SAE Technical Paper 2022-01-0938). In this contribution we show the application of this method on a production vehicle, simulating the flow and acoustic induced vibration of the bonnet. The simulation setup of this study resolves the geometry of the vehicle including the complex details of the bonnet structure, the frunk and the engine compartment. The FEM model for the modal analysis of the bonnet takes into account the complex boundary conditions at the bearings and provides the eigenmodes relevant for the low frequency range. Simulations are conducted in an undisturbed wind tunnel setup and the resulting vibrations are compared to acceleration measurements under wind tunnel and road conditions. Due to the employed hydrodynamic acoustic split approach, the relevance of the
Schwertfirm, Florian, Ocker, Joerg, Hartmann, Michael
AI-Based Package Tray Design Method for Controlling Acoustic Modes in a Sedan2026-01-0716To be published on 06/20/2026
• In this study, we propose a methodology for predicting the acoustic modes and natural frequencies of a sedan using artificial intelligence and demonstrate the feasibility of controlling its acoustic characteristics by modifying the hole distribution of the package tray. In typical sedan structures, the cabin cavity and trunk cavity are acoustically coupled through holes in the package tray. The distribution of these holes significantly affects the natural acoustic modes and frequencies of the vehicle. However, once the exterior shape of the vehicle is finalized during the design phase, options for structural modifications to mitigate noise issues caused by these modes become extremely limited. To address this challenge efficiently, we develop a deep learning-based neural network model trained on data derived from a simplified acoustic analysis model of a sedan that includes a package tray. Finite element analysis is performed to generate acoustic modes and natural frequencies, which
Lee, Jin Woo, Cho, Jaeho, Nam, Younsic, Han, Yongha
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
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
Best-in-Class NVH Optimisation for Electric Powertrains, Holistic Front-Loading Approaches2026-01-0689To be published on 06/20/2026
Achieving best-in-class Noise, Vibration, and Harshness (NVH) in electric powertrains demands a paradigm shift in development methodology. This paper presents a holistic, front-loaded approach to NVH optimisation, leveraging simulation models, machine learning, and target cascading to deliver superior results. By attacking NVH at the source, and integrating data-driven techniques early in the design cycle, significant reductions in development time and reliance on traditional testbed loops are realised. Machine learning algorithms are utilised to accelerate root cause analysis and refine simulation accuracy, while target cascading ensures alignment of system-level performance objectives down to subsystem contributions. Combined, these strategies enable rapid and robust NVH optimisation, setting the benchmark for next-generation electric powertrain development. several application and real life exmaple are shown.
Mehrgou, Mehdi, Garcia de Madinabeitia, Inigo, Graf, Bernhard, Gojo, Josef
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
PSYCHOACOUSTIC ANNOYANCE MODELS ASSESSMENT FOR AUTOMOTIVE FAN-SYSTEMS2026-01-0672To be published on 06/20/2026
Because of automotive electrification, fan systems previously hidden by internal combustion engines could become key contributors to the overall noise behavior. Metrics like overall Sound Pressure Level or Loudness are first order metrics enabling ranking. Yet, second order factors, that are relevant to assess annoyance, are not correctly described using a single criterion. This paper studies the applicability of various Psychoacoustic Annoyance (PA) models in an attempt to address subjective perception of sound quality. Based on pairwise comparison through a jury test with a set of 8 noises at a similar global level, the combined impact of several psychoacoustics metrics was previously determined. This computation includes a signal modulation metric, a frequency content balance and a tonal criterion. To assess this approach, the correlation for fan-system noise annoyance ranking based on its jury test is compared with several PA criteria, starting from initial Zwicker and Fastl model
Scouarnec, Denis, Bennouna, Saad
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
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
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
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
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
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
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
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
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
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
High-Fidelity NVH Analysis Model Development Process for EV Traction Motors Based on Experimental Correlation2026-01-0685To be published on 06/20/2026
This study presents a high-fidelity NVH (Noise, Vibration, Harshness) analysis model development process for EV traction motors. The proposed process consists of two main components: Path refinement through structural stiffness tuning, and Source refinement, focused on the motor’s excitation mechanisms. Model accuracy was validated through comparison of simulation results with dyno test data, with particular focus on the 24th-order electromagnetic vibration observed in an 8-pole, 48-slot motor. Path refinement was achieved through modal correlation between experimental results and finite element (FE) analysis. Nine modal test and simulation stages were conducted, ranging from individual components to the complete motor assembly. Mode shapes were compared using the Modal Assurance Criterion (MAC), and natural frequencies were matched within a 5% error margin by adjusting FE material properties. For the 24th-order electromagnetic vibration, simulation results agreed with test data within
KIM, Donghee, KIM, Dong-Jun, LEE, SangHan, Kim, Seon Hyeong, HWANG, Seung Gyu, Valente, Giorgio, Parisouz, Shahriar, Halse, Christopher
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
Impact of door dynamics on vehicle interior low-frequency vibro-acoustics.2026-01-0679To be published on 06/20/2026
Interior acoustics represent an essential component of driving comfort in electric vehicles. Numerical simulation is an effective approach for assessing design concepts and enhancing acoustic performance. However, a fully coupled vibro-acoustic model for an entire vehicle remains computationally infeasible. Our approach couples mechanical and acoustic modal models on non-conforming interfaces in the low-frequency range, allowing independent mode combinations. Modal coupling reduces the computational effort significantly from full-order systems with millions of degrees of freedom to a selection of modes of the acoustic and mechanical systems. Modal models of the vehicle structure are derived from laser-vibrometer measurements while the interior acoustics are simulated numerically. Since laser measurements are restricted to the vehicle’s exterior surfaces and vibro-acoustic coupling occurs between the inner structural surface and the interior fluid, the structural behavior of the
Gutbrod, Manuel, Gabriel, Christoph, Müller, Gregor Johannes, Toth, Florian
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
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 PhD, Takahiro
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
Retrofit Vibration Mitigation of Launch Vehicle Structures Using Thin Viscoelastic Coatings: Acoustic and Modal Study2026-26-0736To be published on 06/01/2026
Acoustic-induced vibrations pose a significant risk to launch vehicle hardware and payload reliability during critical phases such as lift-off and transonic phase. Reducing such vibrations is especially challenging when the hardware has already been fabricated, limiting the possibility of structural redesign. This study demonstrates a practical post-fabrication solution using a thin PC10 viscoelastic polymer coating applied externally to fully assembled hardware. The PC-10 Thermal Protection System (TPS) is a silicone polymer-based filled compound originally developed by VSSC, ISRO for ablative thermal insulation. Its viscoelastic properties make it suitable for energy dissipation under dynamic loads. Comprehensive evaluations were conducted using both acoustic testing at National Aerospace Laboratories (NAL), Bangalore, and Experimental Modal Analysis (EMA) at ISRO before and after coating application. Results show a substantial decrease in structure response from 150Hz to 2000Hz
Avirah, Nohin K, Panda, Ajay Kumar, Shaikh, Altafhusen
Impact Study of Terrestrial Jamming on GNSS receiver on-board Launch Vehicles and Mitigation Techniques2026-26-0766To 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 analysed in detail. It was observed that there is nearly 3-4dB reduction in carrier to noise ratio and corresponding change in RF AGC gain is also observed. The issue is
A, Mohammed Basim, O T, Anand Shankara, V S, Biju, V Gopal, Biju, V S, Vinoj, K, Balan, C, Radhakrishna Pillai
Coupled Loads Analysis of a Single Stage Launch Vehicle for Vibration test Level Generation2026-26-0741To be published on 06/01/2026
Gaganyaan is an important mission for the Indian space program to put humans into space. The success of the mission depends on the development of required technology and systems. A test vehicle is developed for the technological demonstration for all envisioned abort flight scenarios of Gaganyaan mission. This is new configuration of launch vehicle with single liquid stage and a number of flights are planned. Coupled Loads analysis of launch vehicle system is a standard practice to estimate response and loads for design of structures and generating sine vibration test levels. Usually a vehicle rests on the launch pad through base shroud with horizontal support and no vertical restraint. Upon ignition of the engine, thrust builds up and upon overcoming gravity the vehicle takes off. In the current analysis the launch vehicle is held in position using a holding / retracting mechanism and at a predefined time the vehicle is released. The boundary condition required a novel method to
Kurudimath, Kottresh Maharudraiah, Jalan, Salil, Rose, Jancy
Vibration based methods for Non-destructive prediction of Buckling loads2026-26-0737To be published on 06/01/2026
Using vibration data for prediction of buckling loads have been proven effective for various geometries including rods, plates and shells. The Arbelo approach of the vibration correlation method is derived to improve the reliability of the prediction for cylindrical and spherical shell structures. In this work, a more simplified form of the Arbelo approach is proposed which has higher prediction accuracies of the buckling with lesser pre-load levels. A parameter called Stiffness Decay Index (SDI) is introduced as a measure of the stiffness degradation by normalizing the loaded natural frequency with respect to the unloaded state, offering an effective means of buckling prediction with improved accuracy and without causing any damage or permanent deformation to the structure. Numerical and experimental evaluations of the Stiffness Decay Index are carried out for various geometries. The advantages of using SDI in place of the Arbelo approach of the vibration correlation technique are
Rangarajan, Gopikrishna, V, Vishwajith, Raju, Gangadharan, Dinavahi, Ramkrishna
Design of Acoustical Features for a quitter Aero-engine Test Facility2026-26-0787To be published on 06/01/2026
Indoor aero-engine test facilities (AETF) are generally used to evaluate the performance of both the newly manufactured and repaired/overhauled engines. Aero Engine Research & Design Center (AERDC) has already commissioned several facilities for testing of turbofan engines of around 40 kN thrust class which powers fighter aircrafts. A request has been received from a customer for installation and commissioning of a new test facility for testing of a similar class engine, with a challenge to make it acoustically better than the existing test facilities. The target was set to reduce the sound pressure level (SPL) in the control room and around the test facility as compared to the existing ones. To meet this requirement, a modified layout with a U-type (vertical intake and exhaust) configuration was planned along with specially designed high and low frequency silencers at the intake, exhaust system with an exhaust basket, splitters in the vertical exhaust chamber, and sound absorbing
Gouda, Bansidhar
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
Hierarchical Control Strategy Evaluation and Migration for a Four-Degree-of-Freedom Quarter Commercial Vehicle02-19-03-00144/9/2026
In order to improve the comfort performance in commercial vehicles, this study proposes a hierarchical control strategy that integrates the evaluation and migration of control algorithms. First, a quarter-vehicle model with four-degree-of-freedom (4-DOF) is constructed, incorporating the dynamics of the wheel, frame, driver’s cab, and seat. The key modal characteristics of the model are then verified through amplitude–frequency analysis, confirming their consistency with the typical vibration patterns observed in actual commercial vehicles, which provides the foundation for subsequent control strategy evaluation and migration. Then, based on a standard two-degree-of-freedom (2-DOF) suspension model, a weighted comprehensive evaluation function is developed to account for comfort, structural safety, handling stability, and both time- and frequency-domain performance indicators. Using this evaluation function, various control algorithms—including Skyhook control (SH), acceleration-based
Pan, Ting, Pang, Jianzhong, Wu, Jinglai, Zhang, Jiuxiang, Kang, Gong, Zhang, Yunqing
Reliability-Based Vibration Design of Vehicle Systems with Tuned Mass Dampers (TMD)2026-01-01394/7/2026
Tuned Mass Dampers (TMDs) are widely used in the automotive industry to mitigate Noise, Vibration, and Harshness (NVH) issues across various vehicle systems. These passive devices are particularly effective in reducing structural vibrations in components subjected to resonant excitation. However, real-world applications often face challenges due to manufacturing variability and system-level build differences, which can cause deviations in both the TMD’s tuned frequency (up to ±15%) and the vibration characteristics of the host structure. These uncertainties—in both the TMD properties and the vehicle subsystem dynamics—can be modeled using statistical distributions. This paper presents a generalized methodology for vibration analysis and design under uncertainty, combining reliability engineering with dynamic vibration modeling. The approach formulates a unified mathematical framework that incorporates probabilistic and stochastic modeling to assess TMD performance under a range of
Abbas, Ahmad, Haider, Syed, d'Souza, Suneel
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
A Vehicle-Integrated Validation Method for Weather-Strip Sealing Performance in Automotive Closure Systems2026-01-02004/7/2026
Weather-strip sealing systems are critical to automotive closure performance, influencing water- and dust-tightness, aerodynamic noise control, and overall NVH quality. Conventional validation often relies on flat or straight JIG-based tests that inadequately represent the curved, angled, and non-uniform geometries of real closures such as doors, tailgates, hoods, roofs, and fixed or movable glass. This disparity limits the predictive accuracy of sealing performance in actual vehicles. This study proposes a vehicle-integrated validation framework that mirrors true geometric and contact conditions. The methodology combines finite element analysis (FEA) of both flat JIG and full-vehicle CAD geometries with experimental JIG tests, establishing a baseline for pressure distribution, compression load, and sealing contact behavior. A comparative analysis highlights significant deviations between flat-section predictions and vehicle-specific closure profiles. Results demonstrate that the
Ganesan, Karthikeyan, Seok, Sang Ho
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
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
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
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
New Inverter Switching Control Method to Enhance Sound Quality for Electric Vehicles2026-01-04374/7/2026
Conventional inverter control uses a fixed switching frequency, which leads to high-pitched switching noise in electric vehicles (EVs) that does not vary with vehicle speed. Although EVs are much quieter than traditional internal combustion engine (ICE) vehicles, some EV owners complain about the lack of dynamic driving sound feedback. A new patented technology has been developed to enhance EV sound quality by dynamically controlling the inverter switching frequencies. This technology generates dynamic propulsion sound with new "switching order" features at multiple harmonics, with the pitch proportional to vehicle speed. A constant pulse ratio between the switching frequency and the electric motor RPM is implemented to control the switching order. This reduces switching losses during low-speed operation and provides boosted acoustic feedback to the driver during acceleration, which enhances driving experience during sports driving. Furthermore, a special "EV shifting" sound that
He, Song, Gagas, Brent, Welchko, Brian, Ball, Kerrie, Gong, Cheng
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
Modal Analysis Approach on Vehicle Transient Behavior Considering Roll and Pitch Dynamics2026-01-02104/7/2026
When a vehicle performs planar motion, the tire side force induces a jacking-up effect determined by the suspension roll center height governed by suspension geometry. These jacking forces also excite pitching motion. In this study, the pitching degree of freedom, along with roll degree of freedom, was incorporated in the bicycle model of the vehicle motion, hence it becomes four-degree-of-freedom model, and a new analytical method that applies modal analysis method to the model decomposes the motion of the sprung mass of the vehicle into mutually independent vibration modes. Since the superposition of these vibration modes can reproduce vehicle motion, these vibration modes are the fundamental factors governing sprung-mass behavior. Therefore, understanding how these vibration modes respond to design parameters provides a theoretical foundation to design desired vehicle dynamics from the early stage of car development. This report presents, by conducting modal analysis of the four
Kusaka, Kaoru, Yuhara, Takahiro, Koakutsu, Shingo
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
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