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

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Machine Learning-Based Prediction of Wind-Induced Interior Noise in Ground Vehicles2026-01-0599To be published on 04/07/2026
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
New Inverter Switching Control Method to Enhance Sound Quality for Electric Vehicles2026-01-0437To be published on 04/07/2026
Conventional inverter control uses a fixed switching frequency, which leads to a high-pitched switching noise in electric vehicles (EVs) that does not vary with vehicle speed. Although EVs are generally 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 fixed 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
He, Song, Gagas, Brent, Welchko, Brian, Ball, Kerrie, Gong, Cheng
Lightweight Bubble Sheet Panel To Reduce Inverter Noise and Vibration for Electric Vehicles2026-01-0442To be published on 04/07/2026
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, due to its large radiative panel, becomes a dominant noise source. 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 results in excessive mass, cost, and packaging challenges. A new, patented bubble sheet panel design has been developed to enhance the structural strength and damping of the inverter while significantly reducing its mass. A thin sheet of aluminum or magnesium 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
He, Song, Bobel, Andrew, Naismith, Gregory, Yi, Wenwen, Patruni, Pavan Kumar
Predicting Electric Vehicle Interior Noise Quality from Drive Unit End-of-Line Vibration Testing2026-01-0223To be published on 04/07/2026
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 vibrational 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
Simulation-based prediction and optimization of acoustic comfort in vehicle interiors2026-01-0502To be published on 04/07/2026
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
A System-Level Calibration Framework for Embedded Vision: Integration of Sensor, Firmware, and Software Enhancements2026-01-0013To be published on 04/07/2026
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
NVH characterization of new PWM strategies2026-01-0224To be published on 04/07/2026
Pulse Width Modulation (PWM) technique is widely used to drive AC machines at variable speed, however it generates high frequency harmonics which degrade sound quality. In the last decades, different PWM strategies have been designed to limit switching loss, and/or harmonic generation. Among them, discontinuous strategies are based on the injection of a zero-sequence signal, that strongly impacts the resulting voltage spectrum. An analytic formulation of the zero-sequence signal is proposed by the authors. It allows the creation of new PWM strategies, that can be easily experimented. In this paper, a preliminary study is performed with six new PWM strategies based on this analytic formulation. They are implemented on a basic test bench to perform a NVH characterization. Sound quality metrics are used to qualify the sound signature they produce. The resulting SPL is comparable with that of existing strategies, however their timbre is different in terms of low-frequency content and
Wanty, Salomé, Delpoux, Romain, Glesser, Martin, Totaro, Nicolas, Parizet, Etienne, Degrendele, Karine
Swept Collector Design for the Honda Automotive Laboratories of Ohio Wind Tunnel2026-01-0608To be published on 04/07/2026
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
Elucidation of Flow Mechanisms Modulating Vehicle Wind Noise by using Large-Scale CFD Simulation2026-01-0614To be published on 04/07/2026
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, causes 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. However, 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
Tajima, Atsushi, Hirata, Takumi, Ikeda, Jun, Kamiwaki, Takahiro, Wakamatsu, Junichi, Tsubokura, Makoto
Machine Learning-Based Gear Defect Detection in Electric Vehicle Drive Units Using End-of-Line Vibration Analysis2026-01-0637To be published on 04/07/2026
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
Optimization of Lightweight Gear Blanks to Improve NVH for an Electric Drive Unit2026-01-0001To be published on 04/07/2026
A single-speed electric drive unit (eDU) with multi-stage reduction can have high gear whine due to high pitch-line velocity in the absence of engine masking noise. A comprehensive investigation is conducted focusing on the optimization of the first-stage transfer gear blanks to improve NVH performance and reduce mass for EV applications. A multibody dynamic model of the eDU was constructed, incorporating asymmetric gear blank geometry, shaft elasticity, bearing stiffness, and housing flexibility, in order to characterize realistic operating conditions and simulate gear contact mechanics with high fidelity and computational efficiency. NVH excitation sources, including static transmission error and dynamic meshing force, were systematically evaluated for solid and slotted gear configurations. Based on a DOE optimization study, an 8-slot gear blank design is selected to balance mass reduction, stress, NVH, and manufacturing requirements. Micro-geometry optimization was conducted for the
He, Song, Du, Isaac, Li, Bo, Bahk, Cheonjae, Grguras, Zachary, Baladhandapani, Dhanasekar, Patruni, Pavan Kumar
Enhancing LiDAR Performance under Fog with Adaptive Multi-Echo and Feature-Based Filtering2026-01-0011To be published on 04/07/2026
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 reflection intensity and relative echo positions. Based on predefined rules, the algorithm identifies the
Kaito, Seiya, Zheng, Shengchao, Fujioka, Ibuki, Beppu, Taro
Self-Supervised Gaussian-Based Framework for Robust Static-Dynamic Decomposition and Real-Time Urban Scene Reconstruction2026-01-0010To be published on 04/07/2026
We propose a self-supervised Gaussian-based framework that enhances the robustness and efficiency of static-dynamic decomposition and high-fidelity reconstruction in autonomous driving scenarios. Existing approaches demonstrate promising performance but remain prone to noisy motion segmentation, overfitting on sparse LiDAR observations, and degraded accuracy in low-texture or distant regions, resulting in unstable geometry. To address these challenges, our method introduces a feature fusion module that jointly exploits image semantics and geometric cues, enabling more reliable motion prior extraction under noise and illumination variations. A cross-sequence geometric consistency constraint is further designed to regularize reconstruction across temporal and viewpoint changes, ensuring physically coherent scene representations. In addition, we formulate an efficient Gaussian parameter optimization strategy that constrains scale and normal updates, preventing unrealistic ellipsoid growth
Feng, Runlei, Wang, Ning, Zhang, Zhihao
Analysis of the Impact on Ride Comfort from Splitting the Unsprung Mass in Vehicle Modeling2026-01-0212To be published on 04/07/2026
The study was conducted to investigate the differences in ride comfort analysis between treating the unsprung mass as a whole and modeling it separately. A classical two-degree-of-freedom single-wheel vehicle vibration model and a three-degree-of-freedom single-wheel vehicle vibration model with split unsprung mass were established, with their state-space descriptions determined. The fundamental vibration response quantities of both models were identified, and time-domain simulations under random road excitation were performed using Matlab/Simulink. The results indicate that the two modeling approaches exhibit minimal differences in ride comfort analysis for the sprung mass, but there are certain differences for the unsprung mass. Additionally, for the three-degree-of-freedom single-wheel vehicle vibration model with split unsprung mass, the axle-to-wheel mass ratio was introduced to analyze the changes in the fundamental vibration response quantities when the unsprung mass increases
Jie, Li, Wei, Deng
Acoustic simulation for a vehicle audio system across the full audible frequency2026-01-0226To be published on 04/07/2026
Audio system is an important part of vehicle cabin for various purposes. In vehicle development process, it need be tuned for optimal acoustic performance. Traditionally, this process is performed physically on vehicles. In this paper, a methodology is developed to simulate the acoustic performance of the audio system across the full audible frequency range. To quantify the effectiveness, the p/v acoustic transfer functions of the sound pressures at passengers’ ears over the voltage inputs are measured for 12 different speakers in a production vehicle. As the sound perceived by the passengers depends on both the source and the path, the effort of the numerical study mainly concentrates on two aspects: characterization of the loudspeaker parameters and representation of cabin environment. The speaker parameters are characterized from the sound radiation data measured in 2pi chamber. To represent the vehicle cabin, pure finite element model is applied under 1k Hz while a hybrid FE-SEA is
Yang, Wenlong, Patra, Suresh, Hawes, David, Shorter, Phil
CFD-Based Investigation of Fuel Tank Sloshing: Crash Safety and Noise Concerns2026-01-0490To be published on 04/07/2026
A computational study using the Volume of Fluid (VOF) method in SimericsMP+ was conducted to investigate fuel sloshing in automotive fuel tanks under both crash and sudden stop conditions. The SEALs method was employed to rapidly generate the fuel tank mesh, enabling efficient simulation setup. At the outset, a benchmark sloshing case was simulated and compared against experimental data, showing excellent agreement to validate the simulation method. This simulation method was then applied to the fuel tank sloshing scenarios mimicking crash and sudden stop conditions. The study initially focused on a crash scenario where fuel waves impact valves, pumps, and other internal structures. Capturing these localized impact forces is critical for evaluating the risk of component failure and potential leakage. A baffle-equipped tank was simulated and compared with sensor data. Results show that the computed shock forces on valves and baffles closely matched the measurements, demonstrating the
Jia, Kun, Rahman, Ashique
Bearing Fault Diagnosis Method Based on Optimized VMD and Deep Timing Fusion2026-01-0158To be published on 04/07/2026
In the current field of rolling bearing fault diagnosis, two critical challenges persist. First, it is difficult to effectively extract fault features from nonlinear and non-stationary vibration signals. Second, precise diagnosis remains a challenge, especially when distinguishing between different fault types and capturing incipient faults with weak characteristic information. To address these issues, this paper proposes a novel fault diagnosis method based on adaptively optimized Variational Mode Decomposition (VMD) and Deep Temporal Fusion. First, the method improves the traditional Sparrow Search Algorithm (SSA). It enhances SSA’s global optimization capability through strategies like chaotic population initialization and adaptive perturbation. This improved SSA enables efficient global optimization of VMD’s key parameters. Leveraging these optimized parameters, the method decomposes modal signal components with different center frequencies from the vibration signal. This process
Wen, Chao, Zhong, Hong, Wang, Liangmo, Chen, Yong, Gao, Qiang, Li, Yong
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
Systematic Approach to Attenuate NVH Issues in Hydraulic Steering Gear2026-28-00652/12/2026
In commercial vehicles, Hydraulic Power Assisted Steering (HPAS) gear plays a crucial role in enhancing steering performance by providing hydraulic assistance. The HPAS gear comprises a Directional Control Valve (DCV) assembly, where the input shaft and recirculation units are integrated. The valve system which is known for the heart of the HPAS gear, operates under high-pressure conditions. In the DCV, the input shaft is equipped with bearings to support side loads exerted by the system, and a valve component is freely assembled to minimize friction caused by these side loads. The complexity of the floating valve design results in the less slot volume, leading to cavitation and vibrational noise. While this noise is typically suppressed in internal combustion (IC) engine-powered vehicles, its implementation in electric vehicles (EVs) has led to pronounced audible noise, dominating the system. Experimental vibration analysis of the steering gear reveals both low and high-frequency
Vijayenthran, Praveen, Ayyappan, Rakshna, D, Senthil Kumar, N, Prabhakar
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
Vibration Analysis of Rectangular and Circular Plates with Fixed Edges: Analytical and Computational Validation2026-28-01082/12/2026
This study presents a comparative investigation of the vibration characteristics of rectangular and circular plates with fixed edges using analytical, numerical, and computational approaches. Analytical models based on classical plate theory were employed to calculate natural frequencies and mode shapes, while finite element analysis (FEA) was performed in a CAE tool to provide high-fidelity simulation results. A detailed mesh convergence study confirmed numerical stability, with frequency variations below 1% between successive refinements. Analytical predictions showed excellent agreement with simulation results for lower modes, with errors as low as 0.25% for the rectangular plate and 2.65% for the circular plate. However, higher modes exhibited significant deviations, with errors reaching up to 29.01% for rectangular and 181.52% for circular geometries, highlighting the limitations of closed-form solutions in capturing complex vibrational behavior. Python-based computational tools
N, Suhas, R, Sanjay, Bhaskara Rao, Lokavarapu
Measurement of Light Truck Tire Operating Deflection Shapes Using Scanning Doppler Laser Vibrometry: Issues and Insights10-10-02-00102/10/2026
As internal combustion engines are replaced by quieter electric motors in ground vehicles, noise and vibration sources aside from the powertrain have become relatively more important. This is especially true of tires. Measurement of the dynamic vibratory characteristics of tires is critical to understanding their influence on the noise and vibration performance of vehicles, both outside the vehicle body and inside of it. In this work, the normal modes and operating deflection shapes of a Yokohama Geolander A/T light truck tire are measured using traditional modal analysis techniques as well as a non-contact Scanning Laser Doppler Vibrometry (SLDV) approach. Boundary conditions including free, fixed, loaded, and rotating are implemented to the tire and investigated. Rotating conditions are accomplished in a physical chassis dynamometer environment, with the measured tire mounted on the front axle of a Chevrolet Silverado 1500 pickup truck. Modes of vibration and associated natural
Bastiaan, Jennifer M., Chauda, Gaurav, Baqersad, Javad, Gupta, Arjun, Dhami, Kevalya
Vibration Dynamics of a Half-Car Model Considering Tire–Road Separation02-19-04-00212/9/2026
The vibrating half-car model is used to represent the dynamic behavior of a truck’s dependent suspension system, capturing four degrees of freedom. This research investigates time and frequency responses of vibration behavior of half-car model with possible tire–road separation. This investigation is significant because all previously reported analyses based on the tire-road attachment were incorrect, particularly regarding the tire-road separation phenomenon. The differential equations are extended to enhance the accuracy of the model, incorporating tire–road separation conditions for both wheels. A numerical approach is applied to simulate the vertical and roll dynamics of the system under the separation assumption. The simulation results are validated through experiments conducted using ADAMS View software. Integrating the tire–road separation into the model results in dynamic responses that closely reflect real-world behavior. These findings provide valuable guidance for designing
Nguyen, Quy Dang, Jazar, Reza
A Study in System Design and Plumbing Selection Impacts no Steering System Noise in Medium- and Heavy-Duty Commercial Vehicle Hydraulic Steering Systems02-19-04-00222/5/2026
This study investigates noise, vibration, and harshness (NVH) characteristics of hydraulic steering systems in medium- and heavy-duty commercial vehicles due to hydraulic system design. Utilizing on-vehicle and lab environment testing, primarily a pressure sweep test and speed sweep test, to identify sources of NVH. Testing demonstrated a significant impact to perceptible noise and vibration through changes to system and component design. NVH mitigation is accomplished by reducing pressure pulsations, cavitation, and turbulence within the fluid by changing hydraulic plumbing diameter. Reduction in sound pressure level (SPL) averaged 30% with peak reduction of 75%. While optimizing hose diameter is an effective method for controlling NVH in commercial vehicle hydraulic steering systems, additional studies should be conducted in optimizing plumbing materials and routing.
Bari, Praful Rajendra, Kintner, Jason
Establish Relation of Car Door Window Glass Opening on Door Assembly Dynamic and Vibrational Behavior2026-01-50062/2/2026
Window glass is a component of the side door assembly of cars. It provides a clear vision for passengers and outsiders. It functions as a temporary opening and ventilation system for the car. It is a part of a car’s aesthetics; it adds stiffness to the door and protects the occupants from different weather conditions. The objectives of this study were to understand the effect of fully and partially opened or closed window glass on the dynamic behaviors of door assemblies and to develop a process to assess these dynamic behaviors. An assessment methodology was developed to determine the effects of various window glass positions on the dynamic behavior of the door assembly. An authenticated finite element (FE) model was used to complete this investigation. The finite element model of the door assembly was validated by correlating the modal frequencies with their corresponding mode shapes. The correlated FE model with the window glass fully closed was called the baseline (W0), and eight
Jadhav, Pandurang Maruti, Waghulde, Kishor B., Bhortake, Rupesh V.
Human Detection Capacity of Vehicle Front Sonar Sensors in Light and Small Passenger Cars and Minivan2025-22-00091/22/2026
Sonar sensor systems have been developed to prevent collisions between vehicles and surrounding objects by employing ultrasonic sensors mounted at the front of the vehicle. These systems warn drivers when nearby obstacles are detected. However, relatively few studies have examined the capacity of sonar to detect humans. This study aims to clarify the human detection capacity of front sonar sensors installed in two light passenger cars (LPC-I and LPC-II), one small passenger car (SPC), and one minivan (MNV). The LPC-I, SPC, and MNV were equipped with center and corner sensors, whereas the LPC-II had only corner sensors. Three volunteers—a child, an adult female, and an adult male—participated in the study. Human detectability was assessed using the “maximum detection distance ratio,” defined as the ratio of the maximum detection distance for a volunteer to that for a standard pipe. The results showed that both the center and corner sensors consistently detected front- and side-facing
Matsui, Yasuhiro, Oikawa, Shoko
Comprehensive Evaluation and Development of a Single Cylinder Engine Vehicle for Refinement of NVH Characteristics2026-26-03081/16/2026
The scale of worldwide population presents its own set of difficulties, especially in densely populated cities. Almost every individual has some form of personal transport, which leads to congestion and limited parking space. Automotive manufacturers are scaling down the size of vehicles to resolve these issues to some extent. This paper is based on the NVH development of a single cylinder diesel engine vehicle. It provides an insight into the comprehensive vehicle level NVH refinement approaches adopted. The NVH characteristics of benchmark two-cylinder diesel and baseline vehicle were measured and analyzed for target setting. The performance of each subsystem such as engine mounting, vehicle structure, intake and exhaust was evaluated, and gap analysis was performed against set targets. It was found that the engine mounting system and vehicle structure were inefficient in isolating the excitation forces. The design and location of the mounting system was evaluated using CAE and
Ghale, Guruprasad Chandrashekhar, Baviskar, Shreyas, Bendre, Parag, Kamble, Pranit, Bhangare, Amit, THAKUR, SUNIL, Kunde, Sagar, Wagh, Sachin
Automotive Body Structures’ Section and Joint Enhancement towards NVH Performance2026-26-03311/16/2026
A primary focus of an automotive architecture development is to efficiently distribute the mass, energy, and stiffness throughout the body structure. The car body structure is integrated with load carrying members, pillar structures, panels, and joints. These structural members play a significant role in meeting the body in white (BIW) performance within weight targets. The initial development stage of the vehicle architecture has a flexibility to change the sections and joints as compared to the later stages. An effective utilization of the primary stage of the design will minimize the efforts during the later stage of the performance improvements. One of the critical performance metrics of the BIW is noise vibration and harshness (NVH). For better NVH performance, the BIW must meet certain stiffness and mass requirement that is specific to the vehicle configuration and type. A good design strategy of the section parameters of structural members along with stiffer joints will assist
Senthilkumar, Vibeesh, Raghuvanshi, Jayeshkumar, Lakshe, Shailesh
Challenges in Head-Up Display (HUD) Design for Modern Connected Vehicles: Balancing Functionality with Structural Integrity in an NVH Landscape2026-26-03541/16/2026
A more recent focus on driver comfort and the increasing demand for wide range of information availability make automotive Original Equipment Manufacturers (OEMs) provide advanced features such as Head Up Display (HUD) system. Even though HUD projects vital information onto the windshield/glass, its structural integration comes with significant vibration challenges, leading to display instability and haziness. This paper discusses the significant design parameters influencing the functional effectiveness of HUD system. The structure considered for analysis is the HUD assembly and its integration in vehicle. Cross Car Beam (CCB) turns out to be the critical component of the vehicle structure susceptible to road excitations. Although it’s mass dampens the vibrations inherently, due to the low mass of the HUD, relative oscillation between its projector, mirror, and either the windshield or display causes image distortion This paper investigates in detail the role of HUD structural
Vardhanan K, Aravindha Vishnu, Naidu, Sudhakara, Titave, Uttam
Methodology to Model EMI from E-motors and Controller in the Frequency Range from 30 to 200 MHz2026-26-05241/16/2026
As EMC testing for E-motor drives gains significance due to the involvement of high-frequency switching and high current systems. The radiated emission testing as per CISPR 25 necessitates utilizing an EMC-proof dynamometer to load the E-motor drives during EMC testing inside EMC chamber, which presents a highly complex and expensive testing arrangement. This paper outlines a detailed approach for modelling radiated emission without the usage of such a complex arrangement, by measuring conducted high-frequency currents on the DC and AC lines of motors and MCUs while utilizing a non-EMC-proof motor dynamometer under loaded conditions. In this paper the measurements are conducted in the frequency range of 30 MHz to 200 MHz where usually more issues due to switching noise occurs. The developed model facilities early stage diagnosis of potential EMC issue, enabling mitigation strategies before motor EMC testing. Validation of the method was performed through experimental comparison with
M, Gokul, Patel, Jinay, Mulay, Abhijit B
Low Idle Boom Noise Reduction on Light Weight Agricultural Cabin Tractor2026-26-01001/16/2026
In last two decades, Farm customer expectation on cabin comfort has been increased multifold. To provide the best-in-class customer experience in terms of comfort without adding cost and weight is bigger challenge for all NVH Engineers. It is evident from literature survey that cabin tractors with better comfort is well accepted by customers in US and European Market. Apart from engine excitation, customer has become more sensitive to customer-actuated-accessory noises due to overall reduction in cabin noise in last 2 decades. This paper presents the study conducted on HVAC blower noise in 30HP cabin tractor. Tactile vibrations and cabin noise is not acceptable when AC is switched on due to low frequency modulating nature in frequency range of ~65Hz and 130Hz. The investigation is carried out systematically considering each component of Source-Path-Receiver model. HVAC blower unit as source is diagnosed in detail to understand root cause. Strong dominance of first order of blower been
K, Somasundaram, Chavan, Amit
Simulation Based Optimization of the NVH Characteristics in Modern High Speed Engine During Development Phase2026-26-03261/16/2026
Engine noise mitigation is paramount in powertrain development for enhanced performance and occupant comfort. Identifying NVH problems at the prototype stage leads to costly and time-consuming redesigns and modifications, potentially delaying the product launch. NVH simulations facilitate identification of noise and vibration sources, informing design modifications prior to physical prototyping. Early detection and resolution of NVH problems through simulation can significantly shorten the overall development cycle and multiple physical prototypes and costly redesigns. During NVH simulations, predicting and optimizing valvetrain and timing drive noise necessitates transfer of bearing, valve spring, and contact forces to NVH simulation models. Traditional simulations, involved continuous force data export and NVH model evaluation for each design variant, pose efficiency challenges. In this paper, an approach for preliminary assessment of dB level reductions across design iterations is
Rai, Ankur, Deshpande, Ajay Mahadeo, Yadav, Rakesh
Powertrain Radiated Noise Segregation for Internal Combustion Engines2026-26-03521/16/2026
Powertrain is the most prominent source of Noise and Vibration in the vehicle. Improvement in Powertrain Noise and Vibration is a multifaceted topic due to the complex architecture of the powertrain and the critical role of calibration in defining combustion inputs. Hence, a method to clearly distinguish these aspects is required in order to address the exact problem and decide on course of actions to improve NVH performance of powertrains. This paper discusses a post-processing technique through which experimentally acquired ICE Powertrain Noise can be further segregated in order to identify and address the root source. The segregation methodology requires as input - noise, vibration and cylinder pressure values at various torque conditions across multiple operating points. A MATLAB based code developed by the authors is used to generate correlation between the Cylinder Pressure, Torque and Noise Parameters. The transfer coefficient at every frequency point is calculated using
K J, Kishor, Kulkarni, Shriram, Rawat, Udeshya, Pisal, Sangram, Naidu, Sudhakara
An Analysis of Material Damping Characteristics: A Comparison of Oberst Bar Method and Center Impedance Method and their Relationship to Component Level for EV Application2026-26-03171/16/2026
Damping materials exhibit advantageous mechanical and acoustic characteristics that enhance the structural integrity of systems. These materials find extensive applications across various industries, including automotive, aerospace, and building acoustics, and are widely employed in the development of soundproofing materials. The damping characteristics of materials primarily pertain to the dissipation of vibrational energy, the reduction of oscillations, and the controlling and subsequent attenuation of vibration-induced noise emanating from structures. To improve both structural integrity and acoustic performance, it is crucial to accurately assess the damping properties of these materials. The Oberst bar test method is a standard method used in the automotive, railway and building industry for initial optimization of damping material However, questions have arisen about the degree to which the outcomes of the Oberst test truly reflect real-world applications. Numerous experimental
Kamble, Prashant Prakash, Joshi, Manasi, Jain, Sachinkumar, Harishchandra Walke, Nagesh
Acoustic Challenges in Electric Vehicles: A Comparative Study of HVAC Noise in EVs and ICE Vehicles2026-26-03531/16/2026
With the transition from ICE vehicles to EV’s, the dominant noise sources within the vehicle cabin have shifted from engine noise to auxiliary systems, especially HVAC systems. In conventional vehicles with internal combustion engines (ICE), engine noise tends to mask noise from auxiliary sources. However, in electric vehicles (EVs), the lack of engine noise causes these auxiliary noises, such as those from the HVAC system, to become more prominent and potentially uncomfortable for occupants. The primary objective is to understand how the absence of engine noise in EVs influences the perceived HVAC noises. The research methodology involves static and on-road evaluation of both electric and ICE vehicle having common platform, conducted under same testing conditions. The study aims to quantify and compare the acoustic characteristic differences of HVAC noise between ICEs and EVs, primarily focusing on cabin airflow noise, refrigerant flow noise, and AC compressor noise. Based on the
Patra, Subhashree, Joshi, Rishi, Sharma, Rachit, Lingampelly, Rajaprasad, Neupane, Manoj
New Generation Natural Rubber-Based Bump Stopper with Improved NVH Characteristics2026-26-02921/16/2026
In automotive suspension systems, components like bump stoppers and jounce bumpers play critical roles in controlling suspension travel and enhancing ride comfort. Material selection for these components is driven by functional demands and performance criteria. Traditionally, Natural rubber (NR) has traditionally been favored for bump stopper applications due to its excellent vibration absorption, tear resistance, cost-effectiveness, and biodegradability. However, in more demanding environments, it has been largely replaced by microcellular polyurethane (PU) elastomers, which offer superior durability, environmental resistance, and enhanced noise, vibration, and harshness (NVH) performance. This study revisits NR with the goal of re-establishing its viability by enhancing its performance to match or surpass that of PU. Through compound optimization and advanced material processing techniques, significant improvements have been achieved in NR’s mechanical strength, compression set
Murugesan, Annarajan, Hingalaje, Abhijeet, Perumal, Mathavan, Pawar, Rohit
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
Noise Reduction of Construction Equipment Vehicle Through Structure-Borne and Air-Borne Noise Reduction Strategy2026-26-03181/16/2026
One can witness the constant development and redevelopment of cities throughout the world. Construction equipment vehicles (CEVs) are commonly used on the construction site. However, the noise pollution from construction sites due to the use of CEV has become a major problem for many cities. The construction equipment employed is one of the main causes of these elevated noise levels. The construction workers face a potential risk to their auditory health and well-being due to the noise levels they are exposed to. Different countries have imposed exterior and operator’s ear noise limits for construction equipment vehicles, enabling them to control noise pollution. In this study, three vehicles were selected and checked for NVH performance and found that the operator ear noise level of the identified vehicle is 6 dB(A) higher than the benchmark vehicle level in dynamic conditions, when tested as per ISO 6396. Similarly, there was another vehicle having exterior noise 2 dB(A) higher than
Shinde, Gaurav, Jawale, Pradeep, Jain, Sachinkumar, Harishchandra Walke, Nagesh
Investigation and Reduction of Road Noise due to Transient Road Inputs in Electric Vehicle2026-26-03581/16/2026
Higher road noise is perceived in the cabin when the test vehicle encounters road irregularities like bump or pothole in the public roads. The transfer of transient road inputs inside the body caused objectionable cabin noise. Measurements are conducted at different road surfaces to identify the patch where the objective data well correlated with the noise measured at the public road. Wavelet analysis is carried out to identify the frequency zones since the events are transient in nature. TPA is carried out in time domain to identify the nature of the noise and the dominant path through which the transient road forces are transferring inside the body. Based on the outcome of TPA, various countermeasures like reduction of dynamic stiffness of suspension bushes, TMDs on the path are proposed to reduce the structure borne noise. Criteria which need to be considered for reduction of cabin noise due to transient road inputs is also discussed.
S, Nataraja Moorthy, Rao, Manchi, Selvam, Ebinezer, Raghavendran, Prasath
Dual-Stage Compressor Bracket NVH Optimization for High-Performance 4×4 Electric Vehicles2026-26-03271/16/2026
The rising demand for high-performance 4x4 electric vehicles (EVs) has necessitated development in Noise, vibration and harshness (NVH) optimization, especially in critical components such as compressor bracket. This study focuses on NVH optimization of a dual-stage compressor bracket, comparing its performance against conventional single stage isolation bracket. The dual-stage bracket is evaluated for isolation effectiveness, modal frequency alignment, and overall NVH performance, while ensuring compliance with stiffness targets. Additionally, dual-stage design meets stringent stiffness requirement, confirming structural integrity under dynamic loads. Modal analysis results reveal that the dual-stage configuration effectively shifts critical frequencies away from operational ranges, reducing resonance risks. The results highlight the dual-stage bracket's ability to address NVH challenges in high-performance 4x4 EVs, offering a robust solution for improving cabin comfort and vehicle
Hazra, Sandip, Tangadpalliwar, Sonali
NVH Refinement on the Agriculture Tractor using Coupled Test and Simulation Approach2026-26-03161/16/2026
The Indian farmers choice of agriculture tractor brand is driven by the ease of operation and fuel efficiency. However, the customer preference for operator comfort is driving many tractor OEMs for improvement in noise and vibration at the operator location. Also, the compliance to CMVR regulation for noise at operator ear location and vibration at operator touch point location are mandatory for all the tractors in India. NVH refinement development of the tractor plays a critical role in achieving the regulated noise level and improved tactile vibration In presented work, the airborne sources such as exhaust tail pipe, intake snorkel and cooling fan are quantified by at tractor level through elimination method. The detailed engine level testing in engine noise test cell (hemi anechoic chamber) is carried out to estimate the contribution of engine components to overall noise. The outcome of Noise source identification (NSI) has revealed silencer, timing gear cover and oil sump to be
Gaikwad, Atul Annasaheb, Harishchandra Walke, Nagesh, Yadav, Prasad S, Bankar, Harshal
Experimental Study to Investigate and Control Image Blurriness due to IRVM Vibration2026-26-03211/16/2026
Vibration is one of the prominent factors that determine the quality & comfort level of a vehicle. Moreover, if vibration occurs in areas that are almost entirely within customer touchpoints, it could become a critical factor behind vehicle comfort and affects the brand image within the market negatively. The interior rear-view mirror (IRVM) is one of the important components inside passenger cabin, providing drivers with a clear view of the rear traffic. However, vibrations induced by engine operation, road irregularities, and aerodynamic forces can cause the IRVM to oscillate, leading to image blurriness and compromised visibility and safety. This paper investigates the underlying causes of IRVM vibration and its impact on rear visibility. Through experimental analysis we identify key factors contributing to mirror instability. The findings indicate the specific frequencies of vibration, particularly those resonating with the mirror's natural frequency, significantly exacerbating
Khan, Aamir Naved, Saraswat, Vivek, Jha, Kartik, Singh, Hemendra, Seenivasan, Gokulram, Khan, Nafees
Structural and Micro-Geometry Optimization of an Electric Drive Unit for Whine Noise Reduction2026-26-03151/16/2026
The noise generated by pure electric vehicles (EVs) has become a significant area of research, particularly due to the increasing adoption of electrified propulsion systems aimed at meeting OEM fleet CO₂ reduction targets. Unlike internal combustion engines, which mask many drivetrain noises, EVs expose new challenges due to the quieter operation of electric motors. In this context, the transmission system and gear structures have emerged as primary contributors to noise, vibration, and harshness (NVH) in EVs. The present study provides an NVH study that focuses on the gear whine noise issue that is seen at the vehicle level and cascades to the powertrain level. Comprehensive root cause identification, focusing on the transmission system's structural and dynamic behavior. The research emphasizes modifications to both the gearbox housing and gear structures to reduce noise level, and model validation was all part of the study, which was accompanied by physical test results. Using MBS
Baviskar, Shreyas, Kamble, Pranit, Ghale, Guruprasad, Bendre, Parag, Prabhakar, Shantanu, Kunde, Sagar, Thakur, Sunil, Wagh, Sachin
Analysis of Door Seal Compression and its Influence on NVH Performance in Heavy-Duty Vehicle2026-26-03391/16/2026
This study focuses on the effect of door seal compression prediction and its impact on structure borne NVH in trucks. Customer perception of vibrations are envisaged as quality criteria. It is necessary to determine the contribution of seal stiffness due to seal compression under closed condition of the door rather than considering stiffness of the door seal under uncompressed conditions. The dynamic stiffness of door seal is determined from analysis of non-linear type. The simulations are built using the Mooney - Rivlin model. The parameters influencing the compression of door seals in both two – dimension and three – dimension, are identified from the analysis. This involves contemplating the appropriate seal mounted boundary condition on the body and the door of the vehicle. The stiffness after compression of seal is extracted from this non-linear analysis which is further used to obtain the vibration modes for the doors in the truck cabin. As a part of next step, the compressed
L, Kavya, Ramanathan, Vijay
A Data-Centric Approach to Identify Optimal NVH Simulation Tools and Solvers2026-26-03561/16/2026
The world is moving towards data driven evolution with wide usage tools & techniques like Artificial Intelligence, Machine Learning, Digital Twin, Cloud Computing etc. In automotive sector, the large amount of data being generated through physical and digital test evaluations. Computer-Aided Engineering (CAE) is one of the highest contributors for data generation as physical testing involves high cost due to prototypes & test set-up. The Automotive Noise, Vibration & Harshness (NVH) field is advancing exponentially due to new stringent regulatory norms & customer preferences towards comfort, where digitally advanced techniques are playing a key role in the revolution of NVH. Data generation through CAE tool is a crucial aspect of Engineer’s daily activities and selecting such appropriate CAE software and solvers is critical, as it influences user interface experience, accuracy, solution time, hardware requirements, variability expertise, Design of Experiments ability, and integration
Hipparge, Vinod, Masurkar, Nikita, Arabale, Vinand, Billade, Dayanand
A Strategic Approach to Design Automotive Intake Systems for Achieving a Sporty Acoustic Signature at the Drivers Ear Level2026-26-03281/16/2026
In pursuit of a distinct sporty interior sound character, the present study explores an innovative strategy for designing intake systems in passenger vehicles. While most existing literature primarily emphasizes exhaust system tuning for enhancing vehicle sound quality, the current work shifts the focus toward the intake system’s critical role in shaping the perceived acoustic signature within the vehicle cabin. In this research work, target cascading and settings were derived through a combination of benchmark and structured subjective evaluation study and aligning with literature review. Quantitative targets for intake orifice noise was defined to achieve the desired sporty character inside cabin. Intake orifice targets were engineered based on signature and sound quality parameter required at cabin. Systems were designed by using advanced NVH techniques, Specific identified acoustic orders were enhanced in the intake system to reinforce the required signature in acceleration as well
Sadekar, Umesh Audumbar, Titave, Uttam, Patil, Jitendra, Naidu, Sudhakara
Electromagnetically Levitated Engine Mount2026-26-03421/16/2026
In the evolving landscape of the automotive industry, enhancing passenger comfort and ride quality has become a key differentiator for manufacturers. While suspension systems have traditionally received significant attention, powertrain isolation through engine mounts plays an equally critical role in controlling noise, vibration, and harshness (NVH). Engine mounts are not only responsible for supporting the powertrain’s weight but also for mitigating the transmission of unbalanced engine forces to the vehicle body. Modern engine mount designs aim to eliminate any metal-to-metal contact between the powertrain and chassis, thereby achieving optimal vibration isolation. This study proposes a refined approach to completely decouple the powertrain from the vehicle structure, ensuring minimal vibration transfer and thereby extending the operational life and performance of the engine mount system.
Hazra, Sandip, Naik, Sarang Pramod, More, Vishwas
Developing Advanced CAE Model for Door Glass Regulator Operating Noise Reduction through TEST-CAE Correlation2026-26-03111/16/2026
In recent decades, Computer-Aided Engineering (CAE) has become increasingly critical in the early stages of vehicle development, particularly for performance improvement and weight optimization. At the core of this advancement lies the accuracy of CAE models, which directly impacts design insights and reliable TEST-CAE correlation. Yet, accurately replicating real-world physical systems in virtual environments remains a significant challenge. This research introduces a structured methodology for improving correlation in door system models. It focuses specifically on reducing glass regulator operating noise, a common design issue that can lead to unwanted sounds and passenger discomfort. Traditional CAE models often fail to predict this problem, exposing the limitations of virtual-only validation. To address this gap, the study proposes a modal correlation-based approach aligned with actual assembly stage conditions. This strategy enables more precise assessment of the glass regulator’s
Panuganti, Naresh Kumar, Choi, Seungchan
Investigation of Low Frequency Interior Noise due to Tyre-Road Interaction2026-26-03511/16/2026
Unlike internal combustion engine (IC Engine) vehicles, the rapidly growing electric vehicle (EV) market demands tyres with superior yet often conflicting performance characteristics. The increased weight of EVs, due to their heavy batteries, necessitates robust tyres with reinforcement and higher inflation pressure. Conversely, increased wear due to higher initial torque and the need for lower rolling resistance to extend range, combined with the requirement for better grip for improved handling, call for advanced compound and tread pattern designs. EV tyres need to be stiffer, lighter, and low hysteresis, making it very hard to reduce low-frequency (20-200 Hz) interior noise that was previously masked by engine noise. This study investigates the low-frequency (20-200 Hz) structural-borne interior noise performance of EV tyres using both experimental and simulation tools. By wisely tuning the tyre's stiffness, mass, and damping properties, the necessary noise targets can be achieved
Subbian, Jaiganesh, M, Saravanan
Development of a GUI-Based Pitch Sequence Optimization Tool for Tire Noise Reduction2026-26-03301/16/2026
Tire noise reduction is important for improving ride comfort, especially in electric vehicle due to lack of engine noise and majority of the noise generated in-cabin is from tire-road interaction. Therefore, the tire tread pattern contribution is one of the important criteria for NVH performance apart from other structurally generated noise and vibration. In this work a GUI-based pitch sequence optimization tool is developed to support tire design engineers in generating acoustically optimized tread sequences. The tool operates in two modes: without constraints, where the pitch sequence is optimized freely to reduce tonal noise levels; and with constraints, where specific design rules are applied to preserve pattern consistency and manufacturability. The key point to be considered in this pitch sequence is that it should be reducing the tonal sound and equally spread i.e., the same pitch cannot be concentrated on one side which may lead to non-uniformity. So, the restriction is that
Sampathraghavan, Lakshmi, Ramarathnam, Krishna Kumar, Mantripragada PhD, Krishna Teja, Ramachandran, Neeraj
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