Karl Janssens

• PhD
• R&D Manager at Siemens Industry Software NV

This paper presents an AI-based approach to detect Noise, Vibration and Harshness (NVH) anomalies during end-of-line testing, leveraging a database of experimental recordings from one healthy vehicle and seven other vehicles with anomalies. This study focuses on e-drive maneuvers to detect faults on the front e-axle. To obtain a sufficiently large...

This paper presents the SimRod E-powertrain test setup, designed for validating and demonstrating novel model based testing approaches on an electric vehicle powertrain. In addition, it demonstrates how a classical powertrain test bench can be coupled with an executable digital twin of the rest vehicle, allowing for closed-loop model driven operati...

This paper proposes and compares two sound synthesis techniques to render a moving source for a fixed receiver position based on indoor pass-by noise measurements. The approaches are based on the time-varying infinite impulse response (IIR) filtering and spherical harmonics (SH) representation. The central contribution of the work is a framework fo...

div class="section abstract"> The current trend toward hybrid and electric automotive powertrains increases the complexity of the vehicle development and integration work for the NVH engineers. For example, considering that the combustion noise is reduced or absent, secondary noise sources like drivetrain, auxiliary systems, road and wind noise bec...

Direct field acoustic excitation testing, or DFAX, is gaining the attention of the space industry as a reliable and flexible method to perform acoustic qualification tests of spacecrafts. The test aims at reproducing the sound conditions of the space launch using an array of high-powered loudspeakers placed around the test specimen. To achieve this...

This paper presents a new method for automated tuning of Kalman based virtual sensors. Such virtual sensors use a Kalman filter to estimate non-measured quantities, based on measured data and a model. In order to achieve optimum accuracy, one must characterize the model prediction errors and the measurement errors by means of their respective covar...

Historically, simulations of the vibro-acoustic of products have been mainly performed in the frequency domain. Especially for damping, a key characteristic of vibro-acoustic systems, dedicated modelling formalisms exist (e.g. Perfectly/Automatically Matched Layer (P/AML) to account for unbounded domains, or dedicated frequency-dependent damping ma...

This paper presents a physics-based virtual sensing approach to estimate the full-field pressure responses during direct field acoustic excitation testing (DFAX) through MIMO random control. It makes use of a system level physics based model that consists of an electro-mechanical lumped parameter model of the speaker and a finite element model to d...

This work discusses the possibility of using phase-based motion magnification as a non-destructive inspection tool for defect detection and identification in vibrating panels. Phase-based motion magnification has recently emerged as a potentially disruptive technology in the field of optical methods for vibration engineering. In fact, the method al...

Booming noise influences perceived vehicle quality and passenger comfort. Therefore, it becomes important for automotive manufacturers to have a reliable method for the detection of booming noise. Machine learning models can effectively address this need but need relatively large datasets. In the absence of sufficient data samples, machine learning...

Pre-test analysis is proposed as a methodology to design control strategies for environmental acoustic tests. In the space industry these tests are used to assess the survivability of hardware, which is exposed to harsh dynamic loads in service. In this work an array of loudspeakers and microphones is used in a laboratory to reproduce the acoustic...

Localization and quantification of noise sources are important to fulfill customer and regulation requirements in a such competitive sector like automotive manufacturing. Wind tunnel testing and acoustic mapping techniques based on microphone arrays can provide accurate information on these aspects. However, it is not straightforward to get source...

New products in the automotive and aerospace industries must provide increased energy efficiency and exceed previous performance, safety and reliability. To meet these expectations, the role of simulation continues to grow. Within this context, simulation models are used in real-time embedded applications such as advanced real-time control and vi...

Virtual sensing is an emerging technology with a wide application potential for the industry. The combination of sensor measurement data with simulation models allows the estimation of physical quantities, of which a direct measurement is not feasible, for reasons of, e.g., cost and accessible space. The estimated physical quantities can be system...

Component-based transfer path analysis (TPA) has been developed to predict the exterior sound level contribution from noise-generating components upfront in the design cycle without having to physically integrate them into the vehicle. Virtual pass-by noise predictions for different vehicle variants can be reached by combining the characterization...

In this paper, we are investigating the capabilities of both classical system identification and modern machine learning (time regression neural networks) to derive predictive black-box models which can predict the wheel center loads (WCLs) by making use of either the road disturbances acting on the wheel-patch or strain measurements on the suspens...

The purpose of this paper is to investigate an alternative microphone array configuration to the standard linear array for indoor pass-by noise (PBN) measurement. Indoor PBN measurement allows for vehicle noise to be measured with a higher level of control and repeatability than exterior PBN measurements (ISO 362-1:2015). The interior measurement t...

Rolling element bearing fault diagnostics has been a topic of intensive research in recent decades, as they are critical components of rotating machinery and therefore their failure may result in sudden breakdown of machines and industrial installations. The early and accurate detection of incipient faults on bearings can reduce the production cost...

The potential of the Augmented Kalman Filter algorithm is tested in this paper for joint state-input estimation in structural dynamics field. In view of inverse load identification, the filter is compared with the Transfer Path Analysis Matrix Inversion technique, commonly used for industrial applications. An existing Optimal Sensor Placement strat...

A data-driven methodology is considered in this paper focusing towards the Remaining Useful Life (RUL) prediction. Firstly, diagnostic features are extracted from training data and an analytical function that best approximates the evolution of the fault is determined and used to learn the parameters of an Unscented Kalman Filter (UKF). UKF is based...

The application of machine learning to fault diagnosis allows automated condition monitoring of machines, leading to reduced maintenance costs and increased machine availability. Traditional approaches train a machine learning algorithm to identify specific faults or operational settings. Therefore, these approaches cannot always cope with a dynami...

Comfort plays a very important role in the development of cars. The pistons firing order of an internal combustion engine, by nature, do not generate a constant torque on the crankshaft. At specific crankshaft speed, where the engine’s excitation frequency and the driven-system’s natural frequency coincide, torsional vibrations can excite crankshaf...

Professional drivers of off-road vehicles are often exposed to high levels of vibrations. The continuous exposure to those vibrations can lead to discomfort and physical injuries. Clutch engagement is one of the sources of vibrations. Accelerometers are in general appropriate sensors to measure vibrations. However, due to the historical cost of the...

Gear Transmission Error (TE) is often considered as the main cause of gear whine. TE represents the difference between the perfectly kinematic transmission of motion and the one actually achieved. TE vibrations are extremely small and pose significant measurement challenges. This article demonstrates how low-cost digital encoders can be successfull...

This paper investigates the effect of voltage unbalance fault on current, vibration, acoustic noise and instantaneous power of an open-loop-controlled 1/3 HP and a closed loop controlled 3 kW induction machine drive. Experimental tests are performed in the form of run-ups and the results are plotted as colormaps to visualize the effect of the unbal...

In this paper, a full Acoustic Modal Analysis (AMA) procedure to improve the CAE predictions of the car interior noise level is proposed. Some of the challenges that can be experienced during such an analysis are described and new solutions to face them are proposed. Particular AMA challenges range from the arrangement of the experimental setup to...

Rolling element bearings are common but crucial components of rotating machines being the interface among steady and rotating parts and are responsible for many machine failures and breakdowns. Condition monitoring of machinery using vibration analysis often provides insight and early detection of damage on the bearings. The most widespread method...

In the era of Internet of Things and Industry 4.0, the demand for condition monitoring of rotating machinery in industry becomes ever more significant. In addition to the steps of fault detection and diagnosis, the accurate estimation of the Remaining Useful Life (RUL) of machinery components may provide significant economic merits, optimizing the...

A data-driven methodology is considered in this paper focusing towards the Remaining Useful Life (RUL) prediction. Firstly, diagnostic features are extracted from training data and an analytical function that best approximates the evolution of the fault is determined and used to learn the parameters of an Unscented Kalman Filter (UKF). UKF is based...

This paper presents a pre-processing technique to select the optimal filtering frequency band identifying gear fault signature and use the filtered signal to calculate statistical features. The selected technique the cyclic spectral correlation, as proposed by Antoni [11]. It allows the visualization of excitations of the signal on a map. According...

The integration of the electric motor to the powertrain in hybrid electric vehicles (HEVs) presents acoustic stimuli that elicit new perceptions. The large number of spectral components, as well as the wider bandwidth of this sort of noises, pose new challenges to current noise, vibration and harshness (NVH) approaches. This paper presents a framew...

Interior sound measurements play an important role in vehicle development and refinement. Sometimes hundreds of microphones are installed in an automotive cabin. During test preparation and execution, a lot of time is spent in determining the microphone positions and in tracking cables to the data acquisition channel. A smart acoustic localization...

In this paper, a full Acoustic Modal Analysis (AMA) procedure to improve the CAE predictions of the car interior noise level is proposed. Some of the challenges that can be experienced during such an analysis are described and new solutions to face them are proposed. Particular AMA challenges range from the arrangement of the experimental setup to...

Experimental simulations of random vibrations are important for automotive and aerospace component testing. Shaker excitation signals are typically generated by applying the Inverse Fast Fourier Transform (IFFT) to the desired Power Spectral Density (PSD) profile in combination with randomized phase spectra. However, signals generated in this way w...

The electrification of powertrains in road vehicles renders new interior soundscapes which are perceived by its occupants. The large amount of harmonics that is present in such kind of noises, and the wide frequency band they typically spread, make the design and attainment of sound quality targets a challenging task. This paper aims at proposing a...

During the last two decades there have been several improvements on environmental acoustic qualification testing for launch and space vehicles. Direct field excitation (DFAX) tests using Multiple-Input-Multiple-Output (MIMO) control strategies seems to become the most cost-efficient way for component and subsystem acoustic testing. However there ar...

Electric and hybrid vehicles are very silent, which represents a major advantage for the reduction of noise annoyance in urban areas. The goal of eVADER project is to develop a prototype vehicle combining a high safety for pedestrian and a low noise annoyance for city residents. Several technical solutions are developed: an automatic pedestrian det...

This paper analyses from an experimental standpoint the measurement error in the Instantaneous Angular Speed (IAS) and Torsional Vibration (TV) measurement by means of zebra tapes. A precision gear test rig is exploited to compare against calibrated high accuracy analog encoders and low-cost digital encoders taken as angular references, after perfo...

In the past few years an increasing interest in the minimization of interior noise levels has been observed in the automotive industry. Within this context, experimental Acoustic Modal Analysis (AMA) tests play a crucial role in the optimisation process of the acoustic parameters of car cavities. A first challenging task of such tests is the creati...

Interior noise comfort requirements of modern vehicles are of ever increasing importance in the automotive industry. Within this context, Acoustic Modal Analysis (AMA) plays a crucial role in the optimisation process of the acoustic parameters of car cavities. An (acoustic) modal analysis test can involve a huge amount of measurement points, partic...

: The sound quality (SQ) refinement of engine disturbance as perceived in vehicle cabins is often accessed via psychoacoustic metrics. Loudness, Roughness and Sharpness, as the most regarded metrics in devising SQ targets for low frequency disturbances. However, the use of hybrid and electric powertrains in passenger vehicles bring unusual narrowba...

Multichannel active noise control algorithms have been proposed to deal with sound propagation in enclosures, which base their operation on sensor/actuator positioning conditions that in some applications could not be easily met. In this paper, we investigate a multichannel active sound quality control algorithm, intended to independently control e...

In the automotive industry, one of the most important comfort requirements in designing a high quality vehicle is to avoid or minimize the noise in the passenger compartment. Therefore, an ever increasing interest exists to predict the interior acoustic behavior by means of accurate simulation models both to improve the vehicle NVH performance and...

The combined use of Generalized Inverse Beamforming (GIBF) and Principal Component Analysis (PCA), has demonstrated to be effective in resolving complex and partially correlated sound source distributions in noise source identification problems. However the approach still suffers of some numerical instabilities which can give rise to a wrong identi...

This research is part of a FP7 project supported by the European Commission called "Community oriented solutions to minimize aircraft noise annoyance" (COSMA). The present paper focuses on the development and the application of a methodology for the assessment of changes in airport noise exposure in homelike environments, particularly the design of...

The separation of a measured sound field in uncorrelated sources distributions can be very useful when dealing with sound source localization problems. The use of the Principal Component Analysis (PCA) principle, combined with a Generalized Inverse Beamforming (GIBF) technique, offers the possibility to resolve complex and partially correlated soun...

Certification of vehicle noise emissions for passenger vehicles, motorcycles and light trucks is achieved by measuring external sound levels according to procedures defined by international standards such as ISO362. The current procedure based on a pass-by test during wide-open throttle acceleration is believed far from actual urban traffic conditi...

In this paper, the ML-MM estimator, a multivariable frequency-domain maximum likelihood estimator based on a modal model formulation, will be represented and improved in terms of the computational speed and the memory requirements. Basically, the design requirements to be met in the ML-MM estimator were to have accurate estimate for both of the mod...

COSMA -Community Orientated Solutions to Minimize Aircraft Noise Annoyance -was a European approach within the 7th Framework Programme of the European Commission. Aircraft noise engineering is focused more or less on the reduction of the noise emission for single aircraft components, and separately treating the noise abatement procedures during tak...

Transfer Path Analysis: accurate load prediction beyond the traditional mount stiffness and matrix inversion methods. Steven Dom, Theo Geluk, Karl Janssens, Herman Van der Auweraer The source-transfer-receiver model to approach automotive NVH problems has proven its worth over the last decades. The approach allows splitting up an NVH problem int...

The interior sound perceived in an automotive cabin is a very important attribute in vehicle engineering. Therefore, an industrial interest exists to predict the acoustic behaviour with simulation models. To understand the modelling challenges and improve the modelling know-how, experimental acoustic methods play an important role. Also for trouble...

A method (200) for the characterization of vibrational and/or acoustic transfer path related data of a physical system (100) where vibration or acoustics may play a role. The method (200) has a step of receiving (210) input data for at least one input point of the physical system and/or response data for at least one response point of the physical...

Noise and vibration performance plays an important role in the development of rotating components, such as engines, drivelines, transmission systems, compressors and pumps. The presence of torsional vibrations and other specific phenomena require the dynamic behaviour of systems and components to be designed accurately in order to avoid comfort and...

Electrical vehicles operating at low speed are often too quiet to be detected by pedestrians in time. In order to study the efficiency of additional auditory warning signals they might be equipped with, a sample of 100 sighted and 53 blind listeners was exposed to a virtual road-crossing scenario in which they had to detect whether an approaching v...

Pass-by noise testing is nowadays a well-defined procedure in the development process of motorbikes. Manufacturers facing issues of non-compliance with regulations are looking for techniques to quantify the subsystem noise contributions, enabling the validation of designs for pass-by noise targets, early in the design process. Masking techniques ar...

In this study, noise and vibration measurements were carried out on a multi-phase 12/8 switched reluctance (SR) motor and analyzedwith vibro-acoustic techniques. When evaluating the behaviorof electric powertrains for automotive applications, it is necessary to perform a vibro-acoustic analysis, particularly in view of the acoustic comfort perceive...

Spirometric parameters are the mainstay for diagnosis of COPD, but cannot distinguish airway obstruction from emphysema. We aimed to develop a computer model that quantifies airway collapse on forced expiratory flow--volume loops. We then explored and validated the relationship of airway collapse with computed tomography (CT) diagnosed emphysema in...

In this study different noise and vibration measurements on a multi-phase 12/8 switched reluctance (SR) motor for automotive applications are carried out on a test rig and analysed with vibro-acoustic techniques. When evaluating the behaviour of rotating machinery for HEV applications, it is necessary to perform a vibro-acoustic analysis. The reaso...

Electric or hybrid vehicles are very quiet at low speeds, which represents a very good opportunity to reduce traffic noise annoyance in cities. On the other hand, this may be very hazardous for vulnerable pedestrians (e.g. visually impaired people). The aim of the eV ADER project is to propose solutions in order to add warning sounds to such cars,...

During a field test campaign, Sandia National Laboratories acquired operational data both in parked and rotating conditions on a modified MICON wind turbine with the Sensored Rotor 2 experiment. The objective of the test campaign was to acquire data to develop advanced system identification and structural health monitoring techniques. The data incl...

Operational Path Analysis (OPA) is a method developed in the last few years to tackle the reliable but complex and time-consuming procedure of classical Transfer Path Analysis (TPA). Compared to classical TPA, the OPA method presents several well-known limitations, such as the errors related to cross-coupling between paths, the effect of missing pa...

The sound signature of Electric Vehicles (EV) is significantly different than this of Internal Combustion Engine (ICE) powered vehicles. This EV sound is dominated by complex high frequency tonal components. The present paper investigates the particular problem posed by off-zero harmonics produced by the power electronics. The analysis is performed...