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

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Innovative High-Performance Active Dampers for Effective Mitigation of Helicopter Main Rotor Vibrations2025-01-0163To be published on 04/25/2025
Helicopter vibrations, primarily generated by the main rotor-gearbox assembly, are a major source of concern due to their impact on structural integrity, cockpit instrument durability, and crew comfort. These vibrations are mainly transmitted through the gearbox’s rigid support struts to the fuselage, leading to increased cabin noise and potential damage to critical components. This paper presents a solution for vibration mitigation which involves replacing traditional gearbox support struts with low-weight, high-performance active dampers. Developed by Elettronica Aster S.p.A., these active dampers are designed as electro-hydraulic actuators embedded within a compliant structure. The parallel nested configuration of the system enables high power densities and effective vibration control, significantly reducing the transmission of harmful vibrations to the fuselage. The comprehensive model-based design process is detailed, describing the development and use of a high-fidelity physics
Bertolino, Antonio Carlo, Sorli, Massimo, Porro, Paolo Giovanni, Galli, Claudio
Technical Paper
Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System2025-01-8268To be published on 04/01/2025
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring, resulting in the determination of the coefficients for each segment and the coordinates
Hao, Qi, Zhu, Yuntao, Sun, Wen, Sun, Kai, Sun, Zhiyong, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin
Technical Paper
Research on Shuffle Reduction Control in Dual Motor Hybrid System based on the Motor Torque Intervention Filtering Strategy2025-01-8517To be published on 04/01/2025
Due to the frequent and significant changes of the motor torque of hybrid vehicles during driving often occurring with the driving conditions, and the existence of the transmission tooth surface switching caused by the change in torque direction, as well as the underdamping characteristics caused by the relatively simple transmission system, the vehicle is prone to vehicle body shaking problems under conditions such as the transformation from acceleration conditions to energy recovery conditions, and exit from energy recovery. In order to ensure the ride smoothness of the hybrid vehicle while improving its power response performance, aiming at the underdamping characteristics of its transmission system, this paper develops a transmission PCM vibration suppression control strategy based on the vehicle control system to enhance the torque response and smoothness after Tip out or Tip in after braking. This strategy includes the identification of preconditions and the active intervention
Jing, Junchao, Zhang, Junzhi, Zuo, Botao, Liu, Yiqiang, Huang, Weishan, Xue, Tianjian
Technical Paper
A Proactive System to Anticipate and Store the Damage Information on a Parked Car using Machine Learning Algorithm2025-01-8211To be published on 04/01/2025
Vehicle ADAS Systems majorly comprises of two functions: Driving and Parking. The most common form of damage to the vehicle which goes unnoticed with unidentified cause are parking damages. A vehicle once parked at a certain location may get damaged without knowledge of the user. In this work developed a solution that not only pre-warns the driver but also prepares the vehicle beforehand if it suspects a damage may occur. This eliminates the latency between damage and information capture, detects small damages such as scratches, classifies the type of damage and also informs the user beforehand. This is solution is different from our competitors as the existing solutions informs the user about the scratches/damages, but these solutions are expensive, have high response time, and the damage information is captured after the damage has occurred. The solution consists of the following check blocks: Precondition, Sensor Control and Action Module. The Precondition Module observes the
Debnath, Sarnab, Patil, Prasad, Belur Subramanya, Sheshagiri, Govinda, Shiva Prasad
Technical Paper
Rough Road Vehicle dynamics analysis for vehicle vibration assessment2025-01-8306To be published on 04/01/2025
Multibody dynamics analysis in vehicle development provides a few useful vehicle design guidelines in a few disciplines. The first discipline is vehicle handling simulation, where the major recommendation is suspension geometry and tuning of bushings, shocks and springs. The vehicle dynamics simulations on rough roads give insights about vehicle durability performance: vehicle components, subsystems, and the vehicle body systems. Almost all inputs to the vehicle systems come from tire to ground interactions, tire modeling is the most critical aspect in vehicle durability simulation, e.g. load prediction. The third discipline is the vehicle vibration performance assessment using vehicle dynamic simulations. This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model is simulated on ride roads, first. Hardware measurement can be done in a similar fashion to get the vehicle target performance or bench marking data
Hong, Hyung-Joo, Maddula, Pavan Kumar, Jun, Hyochan
Technical Paper
Machine Learning Based Lane Detection and Lateral Offset Estimation Model for Vehicle Following Applications2025-01-8020To be published on 04/01/2025
Precisely understanding the driving environment and determining the vehicle's exact position are crucial for the safe operation of Autonomous Vehicles. In the vehicle following systems that offer higher energy efficiency by precisely following a lead vehicle, the relative position of the ego vehicle to lane center is a key measure to a safe automated speed and steering control. This article presents a novel Enhanced Lane Detection technique with centimeter-level accuracy in estimating the vehicle offset from the lane center using the front-facing camera. Leveraging state-of-the-art computer vision models, the Enhanced Lane Detection technique utilizes YOLO-V8 image segmentation, trained on a diverse real-world driving scenarios dataset, to detect the driving lane. To measure the vehicle lateral offset, our model introduces a novel calibration method using nine reference markers aligned with the vehicle perspective and converts the lane offset from image coordinates to real-world
Karuppiah Loganathan, Nirmal Raja, Poovalappil, Aman, Naber, Jeffrey, Robinette, Darrell, Bahramgiri, Mojtaba
Technical Paper
A Method for Calculation Flow Resistivity of Kapok Fiber Felt2025-01-8246To be published on 04/01/2025
The flow resistivity is a critical parameter for evaluating the acoustic performance of the porous materials. Accurate determination of flow resistivity is essential for predicting the characteristic impedance and propagation constants of materials. In this paper, a method is proposed to calculate the flow resistivity of kapok fiber felt, aiming to accurately assess the flow resistivity of kapok fiber felt. Based on the dual-porosity equivalent model of kapok fiber felt, it is hypothesized that the flow resistivity is divided into two components. One part from the large pores between fibers, and the other part from the hollow structures within kapok fibers and the micropores on the fiber walls. The contribution of the large pores between fibers to the flow resistivity is calculated using the Tarnow_S model. Meanwhile, the hollow pores within the kapok fibers and the micropores on the fiber walls are represented as an equivalent pore. The slip effects are considered, and experimental
Lin, Jiaman, Kang, Yingzi, Xie, Xinxing, Zhang, Qu, Yang, Shanmiao, Shangguan, Wen-Bin
Technical Paper
Vehicle interior audio system noise prediction based on inverse acoustic approach and directivity pattern2025-01-8640To be published on 04/01/2025
Automotive audio components must meet high quality expectations with ever-decreasing development costs. Predictive methods for the performance of sound systems in view of the optimal locations of loudspeakers in a car can help to overcome this challenge. Use of simulation methods would enable this process to be brought up front and get integrated in the vehicle design process. The main objective of this work is to develop a virtual auralization model of a vehicle interior with audio system. A hybrid simulation approach, which combines both the ray based & finite element approach to predict acoustic transfer functions & auralization effects across the audible frequency range on any chosen vehicle variant. In this paper, Acoustic Vehicle Alerting System (AVAS) speaker tested in an acoustic lab is used. The surface vibration pattern over the surface of the virtual speaker is first extracted based on measured sound pressure data. The acoustic response in a free field generated by the
Baladhandapani, Dhanasekar, Thaduturu, Sai Ravikiran, Du, Isaac
Technical Paper
Aerocoustic Noise Prediction of Passenger Car HVAC by using CFD and Validation with Test Result2025-01-8629To be published on 04/01/2025
The advancement of automobile industries demand compact size of HVAC with better cabin comfort. To achieve this, HVAC has to be optimized in all the aspects such as in shape & size, thermal comfort as well as in noise comfort. From an HVAC perspective, aeroacoustics noise is more significant due to its intensity at higher speeds and frequencies. Since HVAC is mounted inside the cabin, noise can transfer directly inside cabin. To avoid this, noise reduction or noise controlling is of very important. This is possible with HVAC design and simulation at the initial level and acoustic prediction after the CFD/CAA analysis. The present paper describes the aeroacoustic simulation of one of the HVAC to predict the noise during face mode. For that, 1-D simulation has been done initially to find the porosity of heat exchangers and coupled with a CFD solver. STAR CCM+ software is used for the CFD analysis. Transient simulation is performed with compressible fluid using a moving mesh approach. To
Kame, Shubham, Parayil, Paulson, Goel, Arunkumar
Technical Paper
Analysis and Validation of Torque Ripple Cancellation to Reduce Electric Motor Noise for Electric Vehicles2025-01-8573To be published on 04/01/2025
The electric motor represents a significant noise source for electric vehicles (EVs). Conventional hardware-based NVH optimization techniques may prove insufficient, often resulting in trade-offs between motor torque or efficiency performance. The implementation of the motor controlled based torque ripple cancellation (TRC) technology can effectively reduce the targeted order with a minimum impact on other motor performance. This paper presents an explanation of the mathematical theory that underlies the TRC method, with a particular focus on the various current injection methods, including those that enables up to 4DOFs (degrees-of-freedom). In the case study, the injection of controlled fifth or seventh order current harmonics into a three-phase AC motor has been demonstrated to be an effective method for cancelling the most dominant sixth order torque ripple. Furthermore, comprehensive finite-element models are developed for both the electric motor and the motor fixture system to
He, Song, Gong, Cheng, Chang, Le, Peddi, Vinod, Zhang, Peng, GSJ, Gautam
Technical Paper
Research on Noise Optimization Control based on the New Dead Zone Compensation in Dual Motor Hybrid System2025-01-8516To be published on 04/01/2025
In a three-phase voltage source inverter, in order to prevent the direct short circuit of the upper and lower tubes of the bridge arm and ensure the normal operation of the inverter, microsecond-level dead time needs to be added when the power devices are turned on and off. However, due to the dead-time effect, slight distortion may occur in the inverter within the modulation period, and this distortion will eventually lead to harmonic components in the output current after accumulation, thereby generating torque ripple. Against the above background, implementing dead-time compensation strategies is very important. To compensate for the voltage error caused by the dead-time effect, current polarity determination is required first. Then, the dead time is compensated, thereby indirectly compensating for the voltage error caused by the dead-time effect. Regarding the dead-time compensation time, without changing the hardware, this paper proposes a solution to turn off the dead-time
Jing, Junchao, Zhang, Junzhi, Zuo, Botao, Liu, Yiqiang, Yang, Tianyu, Zhu, Lulong
Technical Paper
Impact of Preload and Amplitude on the High-Frequency Behavior of Rubber Bushings in Electric Vehicles: An Experimental Study2025-01-8254To be published on 04/01/2025
Electric vehicles (EVs) are particularly susceptible to high-frequency noise, with rubber eigenmodes significantly influencing these noise characteristics. Unlike internal combustion engine (ICE) vehicles, EVs experience pronounced variations in dynamic preload during torque rise, which are substantially higher. This dynamic preload variation can markedly impact the high-frequency behaviour of preloaded rubber bushings in their installed state. This study investigates the effects of preload and amplitude on the high-frequency dynamic performance of rubber bushings specifically designed for EV applications. These bushings are crucial for vibration isolation and noise reduction, with their role in noise, vibration, and harshness (NVH) management being more critical in EVs due to the absence of traditional engine noise. The experimental investigation examines how preload and excitation amplitude variations influence the dynamic stiffness, damping properties, and overall performance of
Hazra, Sandip, Khan, Arkadip Amitava
Technical Paper
Comparative Study of Optimization Algorithms for 6DOF Design in Electric Vehicle Powertrain Mounting Systems2025-01-8650To be published on 04/01/2025
Optimizing engine mounting systems is a complex task that requires balancing the isolation of vehicle vibrations with the control of powertrain movement within a limited dynamic envelope. This study investigates the application of various optimization algorithms for Six Degrees of Freedom (6DOF) analysis in engine mount design, where the stochastic behavior and probabilistic characteristics of the system present additional challenges. Selecting an appropriate optimization framework is essential for achieving accurate and efficient results. Recent advancements in research have introduced several 6DOF optimization algorithms aimed at determining the optimal stiffness and location of engine mounts. The study evaluates a range of optimization methods, including SHERPA, Quadratic Programming (QP), Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Non-dominated Sorting Genetic Algorithm III (NSGA-III), Nelder-Mead, Multi-Star Local, Response Surface Method (RSM), and Simulated
Hazra, Sandip, Khan, Arkadip
Technical Paper
Experimental Case Study of Sonic Perception of a First-Generation Electric Truck14-14-02-000802/24/2025
The sound generated by electric propulsion systems differs compared to the prevalent sound generated by combustion engines. By exposing listeners to various sound situations, the manufacturer can start understanding which direction to take to achieve compelling battery electric vehicle trucks from a sound perspective. The main objective of this study is to understand what underlying aspects decide the experience and perception of heavy vehicle–related sounds in the context of electrified propulsion. Using a thematic analysis of data collected at a listening experiment conducted in 2020, factors affecting the perception of novel sounds generated by a first-generation electric truck are investigated. A hypothesis is that the experience of driving or being a passenger in electric trucks will affect the rating and response differently compared to listeners not yet experienced with this sound. The results show that the combination of individual preference and experience, hearing function
Nyman, Birgitta, Fagerlönn, Johan, Nykänen, Arne
Journal Article
Design and Development of Wave Spring to Eliminate the Synchronizer Ring Rattle in an Automotive Gearbox2025-28-010002/07/2025
Automotive powertrains are being refined to give good comfort to the occupants. With the refinement of the internal combustion engine, the NVH is improved, and other vehicle noises are surfacing in the vehicle cabin. One such noise is the synchronizer ring rattle noise from the gearbox. The synchronizer rings are assembled freely between the gear and the hub in the gearbox. The manufacturing variations in the gearbox shafts, bearing, and housing bore cause misalignment to the synchronizer ring assembly. This excites the synchronizer rings to rattle. The rattle noise increases when the synchronizer ring is positioned between two different shafts. This rattling reduces the life of the synchronizer. And the rattling noise causes discomfort to the occupants. This research work discusses the different dampening strategies for the synchronizer ring rattle. Higher rattle reduction can be achieved with the wave spring between the input and output shaft. However, the wave spring changes the
K, Barathi Raja, Senthil Raja, T, Kumar, Aneesh, R, Manikandan, Ostwal, Amit
Technical Paper
Analysis and Refinement of Road Boom Noise in Electric Vehicle2025-28-005702/07/2025
Customers are expecting higher level of refinement in electric vehicle. Since the background noise is less in electric vehicle in comparison with ICE, it is challenging for NVH engineers to address even minor noise concerns without cost and mass addition. Higher boom noise is perceived in the test vehicle when driven on the coarse road at a speed of 50 kmph. The test vehicle is rear wheel driven vehicle powered by electric motor. Multi reference Transfer Path Analysis (TPA) is conducted on the vehicle to identify the path through which maximum forces are entering the body. Based on the findings from TPA, solutions like reduction in the dynamic stiffness of the suspension bushes are optimized which resulted in reduction of noise. To reduce the noise further, Operational Deflection Shape (ODS) analysis is conducted on the entire vehicle to identify the deflection shapes of all the suspension components and all the body panels like floor, roof, tailgate, dash panel, quarter panel and
S, Nataraja Moorthy, Rao, Manchi Venkateswara, Raghavendran, Prasath, Selvam, Ebinezer
Technical Paper
NVH Optimization of Mounts for Reduction of Structure Borne Motor and Road Noise in Electric Vehicle2025-28-007202/07/2025
Due to stringent emission norms, all OEMs are shifting focus from Internal combustion engine (ICE) to Electric vehicle (EV). NVH refinement of EVs is challenging due to less background noise in EVs in comparison with ICE vehicles. Motor whine noise is perceived inside cabin till the speed of 20 kmph. Vehicle is powered by electric powertrain (EPT). Electric powertrain is connected to the subframe with the help of three powertrain mounts. Subframe is connected to the body with the help of four mounts. With the help of Transfer Path Analysis (TPA), it is identified that the noise is structure borne and the dominant path is identified. By optimizing the stiffness of the EPT mounts, the structure borne noise levels are reduced. But reducing the stiffness of EPT mount deteriorated the road noise levels. The reason behind deterioration of road noise is investigated. The performance of double isolation of EPT is compared with single isolation of EPT with respect to both road and motor noise
S, Nataraja Moorthy, Rao, Manchi Venkateswara, Raghavendran, Prasath, Selvam, Ebinezer
Technical Paper
A reduced-order beam modelling approach of BIW for torsional and bending stiffness optimization2025-28-018702/07/2025
Noise, Vibration, and Harshness (NVH) simulations of vehicle bodies are crucial for assessing performance during the design phase. However, these simulations typically require detailed computer-aided design (CAD) models and are time-consuming. In the early stages of vehicle development, when only high-level vehicle sections are available, designing the body-in-white (BIW) structure to meet target values for bending and torsional stiffness is challenging and often requires multiple iterations. To address these challenges, this study deploys a reduced-order beam modelling approach. This method involves identifying the beam-like sections and major joints within the BIW and calculating their sectional properties (area, area moments of inertia along the plane’s independent axes, and torsion constant). These components form a simplified skeleton model of the BIW. Load and boundary conditions are applied to the suspension mount locations at the front and rear of the vehicle, and torsional and
Khan, Mohd Zishan Ali, Thanapati, Alok, Deshmukh, Chandrakant
Technical Paper
Enhancing Disc Brake Performance: Investigating Squeal Noise, Wear, and the Application of Functionally Graded Materials in Brake Rotors2025-28-016202/07/2025
Disc brakes play a vital role in automotive braking systems, offering a dependable and effective means of decelerating or halting a vehicle. The disc brake assembly functions by converting the vehicle's kinetic energy into thermal energy through friction. The performances of the brake assembly and user experience are significantly impacted by squeal noise and wear behaviour. This paper delves into the fundamental mechanisms behind squeal noise and assesses the wear performance of the disc brake assembly. Functionally graded materials (FGMs) are an innovative type of composite material, characterized by gradual variations in composition and structure throughout their volume, leading to changes in properties such as mechanical strength, thermal conductivity, and corrosion resistance. FGMs have emerged as a groundbreaking solution in the design and manufacturing of brake rotors, addressing significant challenges related to thermal stress, wear resistance, and overall performance. These
C V, Prasshanth, S, Gurumoorthy, Bhaskara Rao, Lokavarapu, S, Sridhar, S, Badri Narayanan, Kumar, Ajay, Biswas, Sayan
Technical Paper
Vibration Suppression of a Flexible Appendage and Pitch Angle Fuzzy Regulation of a Spacecraft01-18-01-000402/05/2025
In this work, the large-angle rotational movement and vibration suppression of a flexible spacecraft are carried out based on an adjustable system. First the spacecraft model is transformed into a canonical affine control form, then two fuzzy systems are used: The first (of Takagi–Sugeno type) estimates the feedback linearization control law as a whole, while the second (of Mamdani type) adjusts and stabilizes the control parameters using the gradient descent technique and based on the minimization of the control error rather than the tracking error. Stability results are presented in terms of Lyapunov’s theory, and simulation tests illustrate the significant transient robustness of the closed-loop system against perturbations, the accurate trajectory control, and vibration suppression of the flexible spacecraft. Consequently, as will be shown later, the error will stay confined and converges quickly to zero, confirming the smoothing property of the proposed method using fuzzy logic
Bahita, Mohamed
Journal Article
Research on Noise Optimization of Exhaust System for Hydrogen Fuel Cell Vehicles2025-01-700301/31/2025
This paper presents a strategy to reduce exhaust noise in fuel cell vehicles. It focuses on optimizing the exhaust system. The innovation is an integrated muffler device. It combines a vapor separator and an absorptive-reactive muffler. The vapor separator removes moisture from exhaust gases. This prevents damage to sound-absorbing materials. It keeps mufflers functional for longer. Fuel cell vehicles produce noise across a wide frequency range. This makes noise reduction challenging. The absorptive-reactive muffler improves noise attenuation. It works across the full frequency spectrum. The combination of the separator and muffler enhances noise reduction. Simulations show high transmission loss. They also confirm acceptable back pressure. Real-vehicle testing supports these results. The optimized system reduces idle noise by 22.1 dB(A). This is a 32.4% reduction. Blowdown noise is reduced by 46.3 dB(A), or 40.1%. Full-throttle noise drops by over 20 dB(A), a 17.2% decrease. The
Zhou, Jiawang, Jiang, Xiaokun, Qiu, Yongjin, Chen, Jiyuan, Feng, Pengfei, Xie, Qiguang, Xie, Xiaoping, Tan, Ligang
Technical Paper
Experimental Study on Vibration Aging Performance of Vehicle Carbon Canisters2025-01-703001/31/2025
Due to the vibration of the vehicle, the performance of the vehicle carbon canisters will be changed, which will affect its control effect on the fuel evaporation emission. In this study, a vibration test platform capable of simulating vehicle vibration characteristics was used to simulate the possible vibration effects of the vehicle carbon canisters, and to analyze the absorption and desorption performance of the carbon canisters before and after long-term operation and its influence on vehicle evaporation emissions. The results show that the carbon canisters will precipitate the carbon powder after the continuous action of the forward and backward vibration of the vehicle. As a result, the ultimate adsorption and desorption amount of fuel vapor decreased, and the adsorption amount decreased more obviously. In the 48-hour Diurnal Breathing Loss (DBL) test, fuel vapor diffusion is more difficult due to the increased flow resistance of the carbon canisters after vibration, and fuel
Yu, Xiaohong, Liu, Yiyao, Feng, Yifang, Zheng, Yushuo, Chen, Tao, Zhao, Hua
Technical Paper
Research on the Characteristics of an Integrated Thermoelectric Generation, Catalytic Conversion, and Noise Suppression System2025-01-706201/31/2025
In the context of global energy shortages and increasing environmental pollution, improving energy efficiency in automobiles has become a key area of research. Traditional internal combustion engines exhibit low energy conversion efficiency, with a significant portion of fuel energy wasted as exhaust heat. To address this issue, this paper proposes an integrated thermoelectric generation, catalytic conversion, and noise suppression system (ITGCMS) aimed at recovering waste heat from vehicle exhaust, while optimizing emissions and noise reduction through the combination of a catalytic converter and a muffler. A three-dimensional model was established using COMSOL software to thoroughly analyze the system's thermoelectric generation, catalytic conversion, and acoustic performance. The study found that Model B demonstrated the best thermoelectric performance, with an average surface temperature of 300.2°C and a more uniform temperature distribution across the thermoelectric modules
Wu, Ji-Xin, Su, Chu-Qi, Wang, Yi-Ping, Yuan, Xiao-Hong, Liu, Xun
Technical Paper
Formulation of Power Spectral Density of Fuel Cell Stacks in Different Vehicle Models Based on Road Driving Conditions2025-01-708301/31/2025
The durability of fuel cell vehicle (FCV) has always been one of the key factors affecting its large-scale application. However, the durability test methods of FCV and its key components, fuel cell stack (FCS), are incomplete all over the world, especially the lack of vibration test method on FCV. Focused on the FCS, this paper collects the road load spectrum of different vehicle models in their typical working conditions, so as to obtain the power spectral density of FCS of different vehicle models, which is used as the input signal of durability test. Through the FCS testing and analysis of fuel cell passenger car, bus, tractor and cargo van, the results show that the vibration intensity in three directions of FCS of different models is basically less than that of power battery, and only the FCS of fuel cell bus is greater than that of power battery in the direction of vehicle travel.
Wang, Guozhuo, Wu, Zhen, Guo, Ting, Wu, Shiyu, Liang, Rongliang, Nie, Zhenyu
Technical Paper
Research of Pressure Control Based on Dither2025-01-704001/31/2025
The purpose of the paper is to study the impact of dither on how to improve the pressure control capability in common rail system. The dither is directly operating to the inlet metering valve and making the metering flow accuracy. The correlation between rail pressure and metering flow was analyzed. Optimizing the inlet metering valve control is to improve the pressure control. To overcome the hysteresis problem of the inlet metering valve and improve its stability and rapidity on the pressure control. The PID control strategy based on the pressure control were applied in the common rail system and many papers have introduced the logical. But the dither application was seldom introduced in the common rail system. The dither was specified for the inlet metering valve. With the proper dither signal, the stick-slip motion of the metering valve spool converted to a steady one and the dynamic performance was optimized. To verify the theoretical and calibrated the proper dither signal, the
Kuang, Pengda, Chen, Huiqing, Zhang, Jing, Ran, Ye
Technical Paper
Pressure-Dependent Nonlinearities of a Compact Hydropneumatic Strut with Integrated Gas–Oil Chamber10-09-01-000801/24/2025
Hydropneumatic Struts (HPS) are widely implemented in automobile, aerospace, and construction industries, mainly for the purpose of vibration and shock absorption. The HPS design with integrated gas–oil chamber is relatively more compact and robust, while mixing gas and oil inside the HPS generates gas–oil emulsion and more nonlinearities. This study formulated a nonlinear analytical model of the compact HPS with gas–oil emulsion, considering the real gas law and pressure-dependent LuGre friction model. The polytropic version of the van der Waals (vdW) method for real gas is applied to represent the thermodynamic behavior of nitrogen. The experimental data were collected at a near temperature of 30°C with three charging pressures under excitations in the frequency range of 0.5–6 Hz, considering two flow connection configurations between chambers as one- and two-bleed orifice. The nonlinear behavior of the gas volume fraction of the emulsion was identified based on peak strut velocity
Seifi, Abolfazl, Yao, Yumeng, Yin, Yuming, Moore, Masih, Rakheja, Subhash
Journal Article
Airborne Noise Mitigation for Roof-Mounted Air-Conditioning Unit Using Simulation-Based Flow-Induced Noise Detection Approach2025-01-500201/23/2025
In the current world of automobiles, the air-conditioning system plays a crucial role in passenger comfort. Thermal comfort for the passengers, which was earlier a luxury, has now become a basic necessity. This thermal comfort, coupled with ventilation, brings along with it the symbiotic association of flow-induced noise. The subjective prominence of airborne noise from air-conditioning systems increases with higher refinement or masking of structure-borne noise and/or engine noise sources. These systems for commercial vehicles are higher in capacity, complex, and generally placed directly above the passenger seats. Flow-induced noise refinement for such systems is generally difficult and involves multiple physical trials. In the current work presented for a commercial van, the airflow delivery of the air-conditioning system was in line with the requirement. The location of the system, however, resulted in higher noise levels at the passenger ear location. To address this issue, an
Nomani, Mustafa, Kandekar, Ambadas, Latane, Santosh, Manoji, Akash, Tadigadapa, Suresh
Technical Paper
Fault Detection of Diesel Engines Using Artificial Neural Network03-18-02-001001/20/2025
This study presents a method for identifying the reliability state of diesel engines by utilizing artificial neural networks (ANNs). The Sulzer 6AL20/24 marine diesel engine was selected as the test subject for this research. Vibration signals were collected during tests conducted on a laboratory test stand under normal operating conditions and during simulations of six different engine faults. Next, the recorded signals were analyzed and transformed into labeled samples for supervised learning. In this phase, the time histories of the vibration signals were divided into segments and augmented, with several key features calculated for each segment. Highly correlated signals were excluded from further analysis based on the Pearson correlation coefficient. The processed samples were then used to train and fine-tune the ANN. The trained ANN was subsequently used to identify the engine’s reliability state and classify the present fault type. To evaluate the effectiveness of the proposed
Pająk, Michał, Kluczyk, Marcin, Muślewski, Łukasz, Lisjak, Dragutin
Journal Article
NVH Performance of Permanent Magnet Synchronous Motors with Liquid Cooling System10-09-01-000401/13/2025
The aim of the article is to evaluate the effect of the cooling system on the NVH behavior of traction permanent magnets synchronous motors (PMSMs). An effective numerical method is proposed for modeling the fluid–structure interaction in the cooling system of PMSMs. A simplified physical prototype of a cooling jacket of a PMSM is realized by welding two concentric tubes with an internal cavity filled by coolant. A finite element model of the structure is realized. The coolant is modeled as an acoustic domain to account for the fluid–structure interaction in the cavity and a coupled acoustic–structural dynamic problem is solved. The model is validated by experimental modal tests conducted on the prototype of the cooling jacket both with and without the presence of coolant. The validated model is employed to quantify the effect of the cooling system on a real PMSM. The structure of a 10-poles, 12-slots electric machine is modeled by means of finite element method. The model includes the
Barri, Dario, Soresini, Federico, Ballo, Federico, Lucà, Francescantonio, Manzoni, Stefano, Gobbi, Massimiliano, Mastinu, Giampiero
Journal Article
Method for Predicting Lateral Attenuation of Airplane NoiseAIR5662 (Current)01/09/2025
This document describes analytical methods for calculating the attenuation of the level of the sound propagating from an airplane to locations on the ground and to the side of the flight path of an airplane during ground roll, climbout after liftoff, and landing operations. Both level and non-level ground scenarios may be modeled using these methods, however application is only directly applicable to terrain without significant undulations, which may cause multiple reflections and/or multiple shielding effects. This attenuation is termed lateral attenuation and is in excess of the attenuation from wave divergence and atmospheric absorption. The methods for calculating the lateral attenuation of the sound apply to: turbofan-powered transport-category airplanes with engines mounted at the rear of the fuselage (on the sides of the fuselage or in the center of the fuselage as well as on the sides) or under the wings propeller-driven transport-category or general-aviation airplanes
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Information Report
Model Based Emissions and NVH Optimization2024-36-005912/20/2024
Throughout the years, the legislations which drive the vehicle development have experimented constant evolutions. Especially when it comes about pollutant emissions and NVH ( Noise, Vibration & Harshness). However, it is complex to understand which calibration strategy promotes the best balance about lowest levels of emissions, vibrations, and noise if considered the number of inputs to be explored, becoming the searching for the optimum calibration a huge challenge for the development engineering team. This work proposes a methodology development in which complex problems can be solved by model based solutions regarding the best balance finding of emissions reduction and noise attenuation. The methodology is based in machine learning approach which provides a virtual behavior of engine phenomena making possible a wider comprehension of the problem and hence the opportunity to explore enhanced solutions. The study case scenario used to apply the method was a 6.4 liters engine which
Ruiz, Rodrigo Peralta Moraes, Santos, Lucas Resende, Nascif, Gabriel Nobre Alves, Oliveira Ribeiro, Douglas, Pereira, Willyan
Technical Paper
Brake Rotor Thickness Variation and Lateral Run-Out MeasurementsJ3111_202412 (Current)12/12/2024
This SAE Recommended Practice is derived from common methods used within the industry and is not intended to validate a given design or configuration. This SAE Recommended Practice applies to vehicles below 4540 kg of gross vehicle weight rating.
Brake NVH Standards Committee
Recommended Practice
Sound Level Determination for Snowmobiles under Typical Trail Operating ConditionsJ3120_202412 (Current)12/06/2024
This SAE Recommended Practice establishes the method to determine Sound Level of a snowmobile under typical trail operating conditions. Snowmobiles have different engine power levels that depends on the model.
Snowmobile Technical Committee
Recommended Practice
Comprehend Dynamic Behaviour of Vehicle Body for Refined NVH Performance2024-28-026512/05/2024
Modal performance of a vehicle body often influences tactile vibrations felt by passengers as well as their acoustic comfort inside the cabin at low frequencies. This paper focuses on a premium hatchback’s development program where a design-intent initial batch of proto-cars were found to meet their targeted NVH performance. However, tactile vibrations in pre-production pilot batch vehicles were found to be of higher intensity. As a resolution, a method of cascading full vehicle level performance to its Body-In-White (BIW) component level was used to understand dynamic behavior of the vehicle and subsequently, to improve structural weakness of the body to achieve the targeted NVH performance. The cascaded modal performance indicated that global bending stiffness of the pre-production bodies was on the lower side w.r.t. that of the design intent body. To identify the root cause, design sensitivity of number and footprint of weld spots, roof bows’ and headers’ attachment stiffness to BIW
Titave, Uttam Vasant, Zalaki, Nitin, Naidu, Sudhakara
Technical Paper
A Comprehensive Analysis of Electromagnetic NVH in Electric Powertrain2024-28-013612/05/2024
In this paper, a comprehensive analysis of NVH in electric powertrains due to electromagnetic sources is presented. The spatial harmonics model of the traction motor, which is dependent on the motor design structure, rotor poles, stator teeth, and slots, is used for the analysis of the electromagnetic forces from the motor in the electric powertrain. The time harmonics model of the injected current of the motor dependent on the drive electrical circuit and control strategy is also considered for the electromagnetic force calculation. A complete workflow of this electromagnetic NVH analysis for electric powertrain covering the spatial harmonics and time harmonics model is presented. The spatial harmonics model result is presented as flux linkage with respect to dq-axes current and rotor position. The time harmonics are also presented by the injected current of the motor. In addition, a set of operating points on the torque-speed boundary of the traction motor is selected and results are
Joshi, Nakul, Kumar, Vinit, Tsoulfaidis, Antonios, Huang, Zhenhua, Schmaedicke, Marcel, Fialek, Gregory, Zhang, Dapu, Wimmer, Joe
Technical Paper
An Experimental Study of White Deposit Formation on IG Coil in SI Engine2024-28-020612/05/2024
This study meticulously examines the ignition coil (IG), a pivotal component in engine operation, which transforms the low voltage from the battery into the high voltage necessary for spark plug electrode flashover, initiating the combustion cycle. Considering the importance of IG coils in engine operation which has a direct impact on the engine performance. Any failure in the IG coils is judged as a critical failure and encompasses severe repercussions. The paper details an investigation into the issue of ‘White Deposition’ on IG coils. White deposit was observed in IG Coils during new model development in bench level durability test. A comprehensive failure analysis was conducted, employing vibration analysis, thermal analysis, and chemical analysis of the white deposits to ascertain the root cause. Subsequent to identifying the root cause, the study elaborated on hardware design enhancements as a solution. These design changes were rigorously tested on engine benches, confirmed for
Patel, Hardik Manubhai, Gupta, Vineet, Chand, Subhash, Kumar, Nitish
Technical Paper
A Study on Powertrain Modes for Optimizing the NVH Performance2024-28-018712/05/2024
The stiffness and positioning of engine mounts are crucial in determining the powertrain rigid body modes and kinetic energy distribution. Therefore, optimizing these mounts is essential in the automotive industry to separate the torque roll axis (TRA) and minimize vibration. This study aims to enhance mount locations by isolating the engine rigid body modes and predicting the inter-component force (ICF) and transfer function of the vehicle. The individual ICFs for engine mountings are calculated by applying a unit force at the bearing location. Critical frequencies are identified where the amplification exceeds the unit force at the mounting interface between the engine and the frame. The transfer function approach is utilized to assess the vibration at the handlebar. Both ICF and transfer functions analyze the source and path characteristics linked to critical response frequencies. This understanding aids in enhancing mounting positions to minimize vibration levels, thereby enhancing
Jha, Niraj Kumar, Yeezaku, Antony Neomin, Victor, Priyanka Esther, Krishnamurthy, Govindasamy
Technical Paper
An Approach to Reduce Noise Generated by Thermal Management Systems in Electric Vehicles2024-28-021112/05/2024
Electric vehicles are transforming the future of transportation for the world while achieving the goal of sustainable development. While the concept and use of battery-powered vehicles has also penetrated the logistics and supply chain industry, it has also brought upon new challenges during its development. As OEMs strive to develop BEVs with extended range, the components within the propulsion and drivetrain system tend to demand a higher power output from the energy storage systems. This results in BEVs generating higher levels of thermal heat energy, which must be dissipated / rejected for optimal performance and safety. Consequently, to reject this heat, BEVs must utilize thermal management systems with higher capacities. This increase in size is accompanied by the inclusion of many parts that generate noise and contribute to increased noise levels in BEVS. In today’s market, optimization of noise levels is a significant factor when ensuring passenger comfort, while also showing
Shedge, Atharva Vikas, Shalgar, Sandeep, Srivastava, Sarvesh, Nagarhalli, Prasanna V
Technical Paper
A Design Synthesis Approach to Improve HVAC Acoustic Performance of Passenger Vehicles2024-28-022112/05/2024
Noise induced by the Heating, Ventilation and Air conditioning (HVAC) system inside a vehicle cabin can cause significant discomfort to passengers and, in turn, affect the brand image in a competitive automotive market. HVAC acoustic performance has become more prominent with the ongoing transformation from Internal Combustion (IC) to Electric Vehicle (EV) segments. For this reason, acoustic quality is increasingly prioritized as a key design issue throughout the entire development process of the HVAC system. This paper covers the design synthesis considering air handling unit-induced airborne and structure-borne noise of a dashboard-mounted HVAC system to achieve better NVH refinement inside vehicle while maintaining thermal performance. This study began by analysing HVAC-induced blower motor, impeller, air ducts, vents, and recirculation suction noise from the vehicle level to subsystem level and eventually at the component level. At the subsystem level, major noise source
Titave, Uttam Vasant, Naidu, Sudhakara, Kalsule, Shrikant
Technical Paper
Smart Contact Lens for Glaucoma DetectionTBMG-5216012/01/2024
Researchers have been testing ways to continuously and more comfortably detect these tiny fluctuations in pressure. A prototype smart contact lens measures eye pressure accurately, regardless of temperature. The contact lens wirelessly transmits real-time signals about eye pressure across a wide range of temperatures.
Magazine Article
Duct Anechoicity Based on the Acoustic Black Hole Principle2024-01-700611/15/2024
As a novel passive control method, the acoustic black hole (ABH) structure demonstrates achieve energy aggregation efficiently and has the characteristics of lightweight and wide-band noise reduction. This study applies ABH theory to aircraft ducts by incorporating an additional ABH structure into the inner wall design. The spiral structure is specifically engineered to increase the characteristic length of the black hole and lower the cutoff frequency. To validate the effectiveness of this ABH structural design, finite element analysis was conducted to investigate structural frequency response, acoustic energy concentration characteristics, as well as damping and energy dissipation effects. Simulation results indicate significant energy accumulation on the inner wall with ABH structure in frequencies above 800Hz. Additionally, through acoustic-structure coupling analysis, far-field acoustic radiation characteristics were determined for this structural design followed by a
Guo, Yaning, Lv, Peng, Liu, Pengfei, Ning, Donghong
Technical Paper
Research on the Application of High-Static-Low-Dynamic Stiffness Vibration Isolator in Electro-Optical Pods of Unmanned Aerial Vehicles2024-01-701511/15/2024
With the rapid advancement in unmanned aerial vehicle (UAV) technology, the demand for stable and high-precision electro-optical (EO) pods, such as cameras, lidar sensors, and infrared imaging systems, has significantly increased. However, the inherent vibrations generated by the UAV’s propulsion system and aerodynamic disturbances pose significant challenges to the stability and accuracy of these payloads. To address this issue, this paper presents a study on the application of high-static low-dynamic stiffness (HSLDS) vibration isolation devices in EO payloads mounted on UAVs. The HSLDS system is designed to effectively isolate low-frequency and high-amplitude vibrations while maintaining high static stiffness, ensuring both stability during hovering and precise pointing capabilities. A nonlinear dynamic system model with two degrees of freedom is formulated for an EO pod supported by HSLDS isolators at both ends. The model’s natural frequencies are determined, and approximate
Tian, Yishen, Guo, Gaofeng, Wang, Guangzhao, Wei, Wan, Bao, Lingcong, Dong, Guan, Li, Liujie
Technical Paper
An Active Control Method Based on the Study of Dynamic Characteristics of Integrated Electric Drive Systems02-18-01-000211/13/2024
Integrated electric drive systems are characterized by high power density, reliability, and controllability, making them increasingly prevalent in the realm of electric commercial vehicles. However, the direct coupling between the motor shaft and the transmission system has introduced a series of undesirable torsional vibration phenomena. To investigate the dynamic characteristics of electric drive systems in operation for electric commercial vehicles, a comprehensive modeling approach is employed. This modeling framework takes into account key factors such as gear backlash, structural flexibility, and electromagnetic spatiotemporal excitations. Based on this model, the influence of the electrical system on time-varying gear mesh stiffness, gear transmission error, bearing forces, and other factors is investigated. Building upon this foundation, the article proposes an approach for active harmonic voltage injection. This method effectively reduces torque fluctuations, decreases the
Xi, Xin, Chen, Xiaoli, Zhao, Hongyang, Zhao, Xuan, Wei, Jing, Liu, Yonggang
Journal Article
Development and Experimental Validation of a Physics-Based Identification and Mitigation Strategy for Torsional Vibratory Behavior in Medium-Duty Commercial Vehicle Drivelines02-18-01-000111/08/2024
Torsional vibration generated during operation of commercial vehicles can negatively affect the life of driveline components, including the transmission, driveshafts, and rear axle. Undesirable vibrations typically stem from off-specification parts, or excitation at one or more system resonant frequencies. The solution for the former involves getting the system components within specification. As for the latter, the solution involves avoiding excitation at resonance, or modifying the parameters to move the system’s resonant frequencies outside the range of operation through component changes that modify one, or more, component inertia, stiffness, or damping characteristics. One goal of the effort described in this article is to propose, and experimentally demonstrate, a physics-based gear-shifting algorithm that prevents excitation of the system’s resonant frequency if it lies in the vehicle’s range of operation. To guide that effort, analysis was conducted with a numerical simulation
Dhamankar, Shveta, Ali, Junaid, Parshall, Evan, Shaver, Gregory, Evans, John, Bajaj, Anil K.
Journal Article
A Metamaterial that Traps, Amplifies Micro-Vibrations in Small AreasTBMG-5194611/01/2024
The Korea Research Institute of Standards and Science (KRISS) has developed a metamaterial that traps and amplifies micro-vibrations in small areas. This innovation is expected to increase the power output of energy harvesting, which converts wasted vibration energy into electricity, and accelerate its commercialization.
Magazine Article
Investigation of Mid-Frequency Interior Noise due to Tyre-Road Interaction2024-28-000510/17/2024
Over the past twenty years, the automotive sector has increasingly prioritized lightweight and eco-friendly products. Specifically, in the realm of tyres, achieving reduced weight and lower rolling resistance is crucial for improving fuel efficiency. However, these goals introduce significant challenges in managing Noise, Vibration, and Harshness (NVH), particularly regarding mid-frequency noise inside the vehicle. This study focuses on analyzing the interior noise of a passenger car within the 250 to 500 Hz frequency range. It examines how tyre tread stiffness and carcass stiffness affect this noise through structural borne noise test on a rough road drum and modal analysis, employing both experimental and computational approaches. Findings reveal that mid-frequency interior noise is significantly affected by factors such as the tension in the cap ply, the stiffness of the belt, and the properties of the tyre sidewall.
Subbian, Jaiganesh, M, Saravanan
Technical Paper
Harmonic Components Isolation in Vehicle Vibrations: Enhancing Quarter-Car Model Analysis with an Extended Kalman Filter Approach10-08-04-003010/07/2024
This article addresses the essential task of understanding vibrations produced by vehicles to enhance the design of authentic laboratory tests. The article focuses on two primary sources of vibrations: those arising from vehicle–road surface interaction, which is largely random, and those emanating from the drivetrain, characterized as a summation of harmonics with a time-varying fundamental frequency. The method involves the application of the extended Kalman filter (EKF) paired with robust nonlinear least-squares (NLS) initialization to isolate the harmonic components effectively. Through a comprehensive analysis involving mean-square-error (MSE) evaluation via Monte Carlo simulation, considering additive white Gaussian noise (AWGN) and a two-degrees-of-freedom quarter-car model’s simulation response to the road, the research demonstrates the EKF’s proficiency. The results indicate the EKF’s capability to accommodate AWGN with a signal-to-noise ratio (SNR) up to 0 dB and road-induced
Sierra-Alonso, Edgar F., Rouillard, Vincent, Lamb, Matthew
Journal Article
Acoustical Considerations for Aircraft Environmental Control System DesignAIR1826A (Current)10/03/2024
This Aerospace Information Report (AIR) is limited in scope to the general consideration of environmental control system noise and its effect on occupant comfort. Additional information on the control of environmental control system noise may be found in 2.3 and in the documents referenced throughout the text. This document does not contain sufficient direction and detail to accomplish effective and complete acoustic designs.
AC-9 Aircraft Environmental Systems Committee
Information Report
Ride Comfort Efficiency of Passenger Car’s Seat Using the Structure of Negative Stiffness with Various Dynamic Models15-18-01-000310/03/2024
Three dynamic models of a passenger car including the one-dimensional dynamic model, two-dimensional dynamic model, and three-dimensional dynamic model are built to evaluate the ride quality of the passenger car as well as the isolating performance of the SNS (structure of negative stiffness). The decrease of the root-mean-square (RMS) accelerations in the seat and car’s body shaking is the research goal. The investigation results indicate that under all working conditions including the various excitations of the road surface and various velocities of the passenger car, the seat’s acceleration with SNS is strongly ameliorated in comparison without SNS in all three models of the passenger car. Particularly, the RMS seat acceleration with SNS in one-, two-, and three-dimensional models is strongly reduced in comparison without SNS by 76.87%, 66.15%, and 70.59%, respectively. Thus, the seat’s SNS has a good effect in isolating the vertical vibration of the passenger car’s seat. However
Zhang, Lei, Li, Tao, Yang, Guixing
Journal Article
Bemis, BASF develop lightweight hydraulic tank for compact excavators24TOFHP10_0610/01/2024
Bemis Manufacturing and BASF collaborated to develop a lighter-weight and lower-cost hydraulic tank for compact excavators that was recognized with a lightweighting award traditionally reserved for automotive innovations. Receiving an honorable mention in the Enabling Technology category of this year's Altair Enlighten Awards, the development team leveraged a combination of injection molding and vibration welding techniques to lower costs by approximately 20% and reduce mass by about 5% compared to the traditional roto-molding process. The solution also is more eco-efficient, delivering both environmental savings (reductions in lifecycle CO2 emissions) and reducing lifecycle costs.
Gehm, Ryan
Magazine Article
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