Browse Topic: Design Engineering and Styling

Items (42,179)

Probabilistically Extended Ontologies a basis for systematic testing of ML-based systems

2024-01-3002To be published on 07/02/2024

Autonomous driving is a hot topic in the automotive domain, and there is an increasing need to prove its reliability. They use machine learning techniques, which are themselves stochastic techniques based on some kind of statistical inference. The occurrence of incorrect decisions is part of this approach and often not directly related to correctable errors. The quality of the systems is indicated by statistical key figures such as accuracy and precision. Numerous driving tests and simulations in simulators are extensively used to provide evidence. However, the basis of all descriptive statistics is a random selection from a probability space. The difficulty in testing or constructing the training and test data set is that this probability space is usually not well defined. To systematically address this shortcoming, ontologies have been and are being developed to capture the various concepts and properties of the operational design domain. They serve as a basis for the specification

Wiesbrock, Hans Werner, Grossmann, Jürgen

Enabling the security of global time in software-defined vehicles (SGTS, MACsec

2024-01-2978To be published on 07/02/2024

The global time that is propagated and synchronized in the vehicle E/E architecture is used in safety-critical, security-critical, and time-critical applications (e.g., driver assistance functions, intrusion detection system, vehicle diagnostics, external device authentication during vehicle diagnostics, vehicle-to-grid and so on). The cybersecurity attacks targeting the global time result in false time, accuracy degradation, and denial of service as stated in IETF RFC 7384. These failures reduce the vehicle availability, robustness, and safety of the road user. IEEE 1588 lists four mechanisms (integrated security mechanism, external security mechanism, architectural solution, and monitoring & management) to secure the global time. AUTOSAR defines the architecture and detailed specifications for the integrated security mechanism "Secured Global Time Synchronization (SGTS)" to secure the global time on automotive networks (CAN, FlexRay, Ethernet). However, there are also external

Kumaraswamy, Pavithra, Rus, Andrei

Evaluation and simulation of wheel steering functionality on a Road to Rig test bench

2024-01-3000To be published on 07/02/2024

The automotive industry is continuously evolving, demanding innovative approaches to enhance testing methodologies and preventive identify potential issues. This paper proposes an advancement test approach in the area of the overall vehicle system included steering system and power train on a “Road to Rig” test bench. The research aims to revolutionize the conventional testing process by identifying faults at an early stage and eliminating the need to rely solely on field tests. The motivation behind this research is to optimize the test bench setup and bring it even closer to real field tests. Key highlights of the publication include the introduction of an expanded load spectrum, incorporating both steering angle and speed parameters along the test track. The load includes different route and driving profiles like on a freeway, overland and city drive in combination with the steering angles. Furthermore, for the first time, specific driving manoeuvres such as slalom driving and

Kopp, Lennart, Harfmann, Patrick, Niederberger, Lucas, Schwämmle, Timm, Kley, Markus

Numerical Investigation of the Effect of Piston Geometry on the Performance of a Ducted Fuel Injection Engine

2024-01-3024To be published on 07/02/2024

Ducted Fuel Injection (DFI) engines have emerged as a promising technology in the pursuit of a clean and efficient combustion process. This article aims at elucidating the effect of piston geometry on the engine performance and emissions of a metal DFI engine. Three different types of pistons were investigated and the main piston design features including the piston bowl diameter, piston bowl slope angle, duct angle and the injection nozzle position were examined. To achieve the target, computational fluid dynamics (CFD) simulations were conducted coupled to a reduced chemical kinetics mechanism. Extensive validations were performed against the measured data from a conventional diesel engine. To calibrate the soot model, genetic algorithm and machine learning methods were utilized. The simulation results highlight the pivotal role played by piston bowl diameter and fuel injection angle in controlling soot emissions of a DFI engine. An increase in piston bowl diameter increases the room

Shakeel, Mohammad Raghib, Liu, Xinlei, Nyrenstedt, Gustav, Mueller, Charles J., Im, Hong

Analysis of human driving behavior with focus on vehicle lateral control

2024-01-2997To be published on 07/02/2024

The optimization and further development of automated driving functions offers great potential to relieve the driver in various driving situations and increase road safety. Simulative testing in particular is an indispensable tool in this process, allowing conclusions to be drawn about the design of automated driving functions at a very early stage of development. In this context, the use of driving simulators provides support so that the driving functions of tomorrow can be experienced in a very safe and reproducible environment. The focus of the acceptance and optimization of automated driving functions is particularly on vehicle lateral control functions. As part of this paper, a test person study was carried out regarding manual vehicle lateral control on the dynamic vehicle road simulator at the Institute of Automotive Engineering. The basic block for this is the route generation as a result of the evaluation of curve radii from several hundred thousand kilometers of real

Iatropoulos, Jannes, Panzer, Anna, Henze, Roman

FMCW Lidar Simulation with Ray Tracing and Standardized Interfaces

2024-01-2977To be published on 07/02/2024

In pursuit of safety validation of automated driving functions, efforts are being made to accompany real world test drives by test drives in virtual environments. To be able to transfer highly automated driving functions into a simulation, models of the vehicle’s perception sensors such as lidar, radar and camera are required. In addition to the classic pulsed time-of-flight (ToF) lidars, the growing availability of commercial frequency modulated continuous wave (FMCW) lidars sparks interest in the field of environment perception. This is due to advanced capabilities such as directly measuring the target’s relative radial velocity based on the Doppler effect. In this work, an FMCW lidar sensor simulation model is introduced, which is divided into the components of signal propagation and signal processing. The signal propagation is modeled by a ray tracing approach simulating the interaction of light waves with the environment. For this purpose, an ASAM Open Simulation Interface (OSI

Hofrichter, Kristof, Linnhoff, Clemens, Elster, Lukas, Peters, Steven

Enhancing BEV Energy Management: Neural Network-Based System Identification for Thermal Control Strategies

2024-01-3005To be published on 07/02/2024

Modeling thermal systems in Battery Electric Vehicles (BEVs) is crucial for enhancing energy efficiency through predictive control strategies, thereby extending vehicle range. A major obstacle in this modeling is the often limited availability of detailed system information. This research introduces a methodology using neural networks for system identification, a powerful technique capable of approximating the physical behavior of thermal systems with minimal data requirements. By employing black-box models, this approach supports the creation of optimization-based operational strategies, such as Model Predictive Control (MPC) and Reinforcement Learning-based Control (RL). The system identification process is executed using MATLAB Simulink, with virtual training data produced by validated Simulink models to establish the method's feasibility. The neural networks utilized for system identification are implemented in MATLAB code. This study conducts a comparative analysis between

Franke, Kai, Hemkemeyer, David, Schutzeich, Patrick, Schäfers, Lukas, Pischinger, Stefan

Investigation of Stator Cooling Concepts of an Electric Machine for Maximization of Continuous Power

2024-01-3014To be published on 07/02/2024

With the automotive industry's increasing focus on electromobility and the growing share of electric cars, new challenges are arising for the development of electric motors. The requirements for torque and power of traction motors are constantly growing, while installation space, costs and weight are increasingly becoming limiting factors. Moreover, there is an inherent conflict in the design between power density and efficiency of an electric motor. Thus, a main focus in today's development lies on space-saving and yet effective and innovative cooling systems. This paper presents an approach for a multi-physical optimization that combines the domains of electromagnetics and thermodynamics. Based on a reference machine, this simulative study examins a total of nine different stator cooling concepts varying the cooling duct positions and end-winding cooling concepts. To ensure the highest possible comparability, the rotor geometry as well as the overall dimensions in terms of outer

Reinecke, Mike, Karayel, Akif, von Schöning, Hendrik, Schaefer, Uwe, Moullion, Matthias, Faessler, Victor, Lehmann, Robert

Additively Manufactured Wheel Suspension System with Integrated Conductions and Optimized Structure

2024-01-2973To be published on 07/02/2024

Increasing urbanisation and the growing environmental awareness in society require new and innovative vehicle concepts. In the present work, the design freedoms of additive manufacturing (AM) are used to develop a front axle wheel suspension for a novel modular vehicle concept. The development of the suspension components is based on a new method using industry standard load cases for the strength design of the components. To design the chassis components, first the available installation space is determined and a suitable configuration of the chassis components is defined. Furthermore, numerical methods are used to identify component geometries that are suitable for the force flow. The optimisation setup is selected in a way that allows to integrate information, energy and material-carrying conductors into the suspension arms. The conductors even serve as load-bearing structures because of the matching design of the components. High-strength light metals are used to minimise the

Weitz, Fabian, Debnar, Christian, Frey, Michael, Gauterin, Frank

Optimal and Prototype Dimensioning of Electrified Drives for Automated Driving

2024-01-3021To be published on 07/02/2024

Electrified drives will change significantly in the wake of the further introduction of automated driving functions. Precise drive dimensioning, taking automated driving into account, opens up further potential in terms of drive operation and efficiency as well as optimal component design. Central element for unlocking the dimensioning potentials is the knowledge about the driving functions and their application. In this paper the implications of automated driving on the drive and component design are discussed. A process and a virtual toolchain for electric drive development from concept optimization to detailed component dimensioning is presented. The process is subdivided into a concept optimization part for finding the optimal drive topology and layout and a detailed prototype dimensioning process, where the final detailed drive dimensioning is carried out. Furthermore. the detailed simulation allows the drive investigation in representative customer operation as well as automated

Sturm, Axel Wolfgang, Brandes, Gerrit, Sander, Marcel, Henze, Roman, Küçükay, Ferit

Simulating Cloud Environments of Connected Vehicles for Anomaly Detection

2024-01-2996To be published on 07/02/2024

The emergence of connected vehicles is driven by increasing customer and regulatory demands. To meet these, more complex software applications, some of which require service-based cloud and edge backends, are developed. Due to the short lifespan of software, it becomes necessary to keep these cloud environments and their applications up to date with security updates and new features. However, as new behavior is introduced to the system, the high complexity and interdependencies between components can lead to unforeseen side effects in other system parts. As such, it becomes more challenging to recognize whether deviations to the intended system behavior are occurring, ultimately resulting in higher monitoring efforts and slower responses to errors. To overcome this problem, a simulation of the cloud environment running in parallel to the system is proposed. This approach enables the live comparison between simulated and real cloud behavior. Therefore, a concept is developed mirroring

Weiß, Matthias, Stümpfle, Johannes, Dettinger, Falk, Jazdi, Nasser, Weyrich, Michael

Current and Torque Harmonics Analysis of Triple Three-Phase Permanent-Magnet Synchronous Machines with Arbitrary Phase Shift Based on Model-in-the-Loop

2024-01-3025To be published on 07/02/2024

Multiple three-phase machines have become popular in recent due to their reliability, especially in the ship and airplane propulsions. These systems benefit greatly from the robustness and efficiency provided by such machines. However, a notable challenge presented by these machines is the growth of harmonics with an increase in the number of phases, affecting control precision and inducing torque oscillations. The phase shift angles between winding sets are one of the most important causes of harmonics in the stator currents and machine torque. Traditional approaches in the study of triple-three-phase or nine-phase machines mostly focus on specific phase shift, lacking a comprehensive analysis across a range of phase shifts. This paper discusses the current and torque harmonics of triple-three-phase permanent magnet synchronous machines (PMSM) with different phase shifts. It aims to analyze and compare the impacts of different phase shifts on harmonic levels. To verify the assumption

Li, Yu, Shi, Bufan, Andert, Jakob

What is going on around the Automotive PowerNet - An overview of state-of-the-art PowerNet, insights into the new trends, and a simulation solution to keep pace with architectural changes

2024-01-2985To be published on 07/02/2024

The automotive PowerNet is facing a major transformation. The three main drivers are: • Increasing power • Availability requirements • PowerNet complexity and cost reduction These driving factors result in a wide variety of possible future PowerNet topologies. The increasing power demand is among others caused by the progressive electrification of formerly mechanical components and the trend of increasing number of comfort loads. This leads to a steady increase in installed electrical power. X-by-wire systems and autonomous driving functions result in higher availability requirements. As a result, the power supply of all safety-critical loads must always be kept sufficiently stable. To reduce costs and increase reliability, the car manufacturers aim to reduce the complexity of the PowerNet System, including the wiring harness and the controller network. The wiring harness e.g., is currently one of the costliest parts of modern cars. These challenges are met with different concepts. To

Jagfeld, Sebastian Michael Peter, Weldle, Richard, Knorr, Rainer, Fill, Alexander, Birke, Kai Peter

Graph based cooperation strategies for automated vehicles in mixed traffic

2024-01-2982To be published on 07/02/2024

In the context of urban smart mobility, vehicles have to communicate with each other, surrounding infrastructure, and other traffic participants. By using Vehicle2X communication, it is possible to exchange the vehicles’ position, driving dynamics data, or driving intention. This concept yields the use for cooperative driving in urban environments. Based on current V2X-communication standards, a methodology for cooperative driving of automated vehicles in mixed traffic scenarios is presented. Initially, all communication participants communicate their dynamic data and planned trajectory, based on which a prioritization is calculated. Therefore, a decentralized cooperation algorithm is introduced. The approach is that every traffic scenario is translatable to a directed graph, based in which a solution for the cooperation problem is computed via an optimization algorithm. This solution is either computed decentralized by various traffic participants, who share and compare their

Flormann, Maximilian, Henze, Roman

Neural Network Modeling of Black Box Controls for Internal Combustion Engine Calibration

2024-01-2995To be published on 07/02/2024

The calibration of Engine Control Units (ECUs) for road vehicles is challenged by stringent legal and environmental regulations, coupled with short development cycles. The growing number of vehicle variants, although sharing similar engines and control algorithms, requires different calibrations. Additionally, modern engines feature increasingly number of adjustment variables, along with complex parallel and nested conditions within the software, demanding a significant amount of measurement data during development. The current state-of-the-art (White Box) model-based ECU calibration proves effective but involves considerable effort for model construction and validation. This is often hindered by limited function documentation, available measurements, and hardware representation capabilities. This article introduces a model-based calibration approach using Neural Networks (Black Box) for two distinct ECU functional structures with minimal software documentation. The ECU is operated on

Meli, Matteo, Wang, Zezhou, Bailly, Peter, Pischinger, Stefan

Simulation of Hydrogen Combustion in Spark Ignition Engines Using a Modified Wiebe Model

2024-01-3016To be published on 07/02/2024

Due to its physical and chemical properties, hydrogen is an attractive fuel for internal combustion engines, providing grounds for studies on hydrogen engines. It is common practice to use a mathematical model for basic engine design and an essential part of this is the simulation of the combustion cycle, which is the subject of the work presented here. One of the most widely used models for describing combustion in gasoline and diesel engines is the Wiebe model. However, for cases of hydrogen combustion in DI engines, which are characterized by mixture stratification and in some cases significant incomplete combustion, practically no data can be found in the literature on the application of the Wiebe model. Based on Wiebe's formulas, a mathematical model of hydrogen combustion has been developed. The model allows making computations for both DI and PFI hydrogen engines. The parameters of the Wiebe model were assessed for three different engines in a total of 26 operating modes. The

Osetrov, Oleksandr, Haas, Rainer

Harmonic injection method for NVH optimization of permanent magnet synchronous motors considering the structural characteristics of the machine

2024-01-3015To be published on 07/02/2024

Noise, vibration and harshness (NVH) is one of the most important performance evaluation aspect of electric motors. Among the different causes of the NVH issues of electrical drives, the high-frequency spatial and temporal harmonics of the electrical drive system is of great importance. To reduce the tonal noise of the electric motors, harmonic injection methods can be applied. However, a lot of the existing related work focuses more on improving the optimization process of the parameter settings of the injected current/flux/voltage, which are usually limited to some specific working conditions. The applicability and effectivity of the algorithm to the whole frequency/speed range are not investigated. In this paper, a multi-domain pipeline of harmonic injection controller design for a permanent magnet synchronous motor (PMSM) is proposed. And the structural properties of the machine described by 2-dimensional transfer functions are used to help effectively set proper harmonic injection

Fu, Tongfang, Xu, Zhipeng, Günther, Marco, Pischinger, Stefan, Böld, Simon

The 3D-CFD Contribution to H2 Engine Development for CV and Off-Road Application

2024-01-3017To be published on 07/02/2024

The hydrogen engine is one of the promising technologies that enables carbon-neutral mobility, especially in heavy-duty on- or off-road applications. In this paper, a methodological procedure for the design of the combustion system of a hydrogen-fueled, direct injection spark ignited commercial vehicle engine is described. In a preliminary step, the ability of the commercial 3D computational fluid dynamics (CFD) code AVL FIRE classic to reproduce the characteristics of the gas jet, introduced into a quiescent environment by a dedicated H2 injector, is established. This is based on two parts: Temporal and numerical discretization sensitivity analyses ensure that the spatial and temporal resolution of the simulations is adequate, and comparisons to a comprehensive set of experiments demonstrate the accuracy of the simulations. The measurements used for this purpose rely on the well-known schlieren technique and use helium as a safe substitute for H2. They reveal how the jet properties

Cassone Potenza, Magda Elvira, Gaballo, Maria Rosaria, Geiler, Jan Niklas, Iacobazzi, Marino, Cornetti, Giovanni, Kulzer, Andre Casal

Computational Method to Determine the Cooling Airflow Utilization Ratio of Passenger Cars Considering Component Deformation

2024-01-2975To be published on 07/02/2024

In order to improve the efficiency of passenger cars, developments focus on decreasing their aerodynamic drag, part of which is caused by cooling air. Thus, car manufacturers try to seal the cooling air path to prevent leakage flows. Nevertheless, gaps between the single components of the cooling air path widen due to the deformation of components under aerodynamic load. For simulating the cooling airflow utilization ratio (CAUR), computational fluid dynamics (CFD) simulations are used, which neglect component deformation. In this paper, a computational method aiming at sufficient gap resolution and determining the CAUR of passenger cars under the consideration of component deformation is developed. Therefore, a partitioned approach of fluid structure interaction (FSI) simulations is used. The fluid field is simulated in OpenFOAM, whereas the structural simulations are conducted using Pam-Crash. In order to validate the simulation results, the CAUR of a battery electric and an internal

Hübner, Jan Marcel, Hähnel, Mathias, Lange, Sven, Lemke, Matthias, Joksimovic, Ivan

Impact of AdBlue Composition and Water Purity on Particle Number Increase

2024-01-3012To be published on 07/02/2024

Previous studies have shown that dosing AdBlue into the exhaust system of diesel engines to reduce nitrogen oxides can lead to an increase in the number of particles (PN). In addition to the influencing factors of exhaust gas temperature, exhaust gas mass flow and dosing quantity, the dosed medium itself (AdBlue) is not considered as a possible influence due to its regulation in ISO standard 22241. However, as the standard specifies limit value ranges for the individual regulated properties and components for newly sold AdBlue, in reality there is still some margin in the composition. This paper investigates the particle number increase due to AdBlue dosing using several CPCs. The increase in PN is determined by measuring the number of particles after DPF and thus directly before dosing as well as tailpipe. Several AdBlue products from different sources and countries are measured and their composition is also analyzed with regard to the limit values regulated in the standard. This

Herold, Tim, Noone, Patrick, Beidl, Christian, Boldt, Thomas, Hochholzner, Michael, Kontin, Sinisa

Turbocharging system selection for a hydrogen-fuelled spark-ignition internal combustion engine for heavy-duty applications

2024-01-3019To be published on 07/02/2024

Nowadays, green hydrogen can play a crucial role in a successful clean energy transition, thus reaching net zero emissions in the transport sector. Moreover, hydrogen exploitation in internal combustion engines is favoured by its suitable combustion properties and quasi-zero harmful emissions. High flame speeds enable a lean combustion approach, which provides high efficiency and reduces NOx emissions. However, high air flow rates are required to achieve the load levels typical of heavy-duty applications. In this framework, the present study aims to investigate the required boosting system of a 6-cylinder, 13-liter heavy-duty spark ignition engine through 1D numerical simulation. A comparison among various architectures of the turbocharging system and the size of each component is presented, thus highlighting limitations and potentialities of each architecture and providing important insights for the selection of the best turbocharging system

Pucillo, Francesco, Millo, Federico, Piano, Andrea, Giordana, Sergio, Rapetto, Nicola, Paulicelli, Fabio

Challenges of measuring low levels of CO2 and NOx on H2-ICE

2024-01-2998To be published on 07/02/2024

Society is moving towards climate neutrality where hydrogen fuelled combustion engines (H2 ICE) could be considered a main technology. These engines run on hydrogen (H2) so carbon-based emission are only present at a very low level from the lube oil. The most important pollutants NO and NO2 are caused by the exhaust aftertreatment system as well as CO2 coming from the ambient air. For standard measurement technologies these low levels of CO2 are hard to detect due to the high water content. Normal levels of CO2 are between 400-500 ppm which is very close or even below the detection limit of commonly used non-dispersive-infrared-detectors (NDIR). As well the high water content is very challenging for NOx measuring devices, like chemiluminescence detectors (CLD), where it results in higher noise and therefore a worse detection limit. Even for Fourier-transformed-infrared-spectroscopy-analysers (FT-IR) it is challenging to deal with water content over 15% without increased noise. The goal

Jakubec, Philipp, Roiser, Sebastian

A Study on RANC Technique for Server-based Control Filter Optimization

2024-01-2960To be published on 06/12/2024

Broadband active noise control algorithms require high-performance so multi-channel control to ensure high performance, which results in very high computational power and expensive DSP. When the control filter update part need a huge computational power of the algorithm is separated and calculated by the server, it is possible to reduce cost by using a low-cost DSP in a local vehicle, and a performance improvement algorithm requiring a high computational power can be applied to the server. In order to achieve the above goal, this study analyzed the maximum delay time when communication speed is low and studied response measures to ensure data integrity at the receiving location considering situations where communication speed delay and data errors occur. Accelerometer and microphone sensor signals are transmitted from the local controller to the server using a commercial wireless communication service, and the server receives them and inputs them into an algorithm to create a control

Oh, ChiSung, Ih, Kang-Duck, Kim, Hyounsuk

AI-Based Optimization Method of Motor Design Parameters for Enhanced NVH Performance in Electric Vehicles

2024-01-2927To be published on 06/12/2024

The high-frequency whining noise produced by motors in modern electric vehicles causes a significant issue, leading to annoyance among passengers. This noise becomes even more noticeable due to the quiet nature of electric vehicles, which lack other noises to mask the high-frequency whining noise. To improve the noise caused by motors, it is essential to optimize various motor design parameters. However, this task requires expert knowledge and a considerable time investment. In this study, we explored the application of artificial intelligence to optimize the NVH performance of motors during the design phase. Firstly, we selected and modeled three benchmark motor types using Motor-CAD. Machine learning models were trained using Design of Experiment methods to simulate batch runs of Motor-CAD inputs and outputs. By applying AI, we developed a CatBoost-based regression model to estimate motor performance, including NVH and torque based on motor design parameters, achieving an impressive

Noh, Kyoungjin, Lee, Dongchul, Jung, Insoo, Tate, Simon, Mullineux, James, Mohd Azmin, Farraen

Frequency Response Analysis of Fully Trimmed Models using Compressed Reduced Impedance Matrix Methodology

2024-01-2947To be published on 06/12/2024

As vibration and noise regulations become more stringent, numerical models need to incorporate more detailed damping treatments. Commercial frameworks, such as Nastran and Actran, allow the representation of trim components as frequency-dependent reduced impedance matrices (RIM) in frequency response analysis of fully trimmed models. The RIM is versatile enough to couple the trims to modal-based or physical components. If physical, the trim components are reduced on the physical coupling degrees of freedom (DOFs) for each connected interface. If modal, the RIMs are projected on the eigenmodes of the connected component. While a model size reduction is achieved compared to the original model, most numerical models possess an extensive number of interfaces DOFs, either modal or physical, leading to large dense RIM which triggers substantial memory and disk storage. Thus, the approach faces challenges related to storage capacities and efficiency, due to the demanding computational and

Paiva, Andre, Verhaegen, Julien, Lielens, Gregory, Van den Nieuwenhof, Benoit

Efficient engine encapsulation strategy using poroelastic finite element simulation

2024-01-2957To be published on 06/12/2024

With the increasing importance of electrified powertrains, electric motors and gear boxes become an important NVH source especially regarding whining noises in the high frequency range. Engine encapsulation noise treatments become often necessary and present some implementation, modeling as well as optimization issues due to complex environments with contact uncertainties, pass-throughs and critical uncovered areas. Relying purely on mass spring systems is often a too massive and relatively unefficient solution whenever the uncovered areas are dominant. Coverage is key and often a combination of hybrid backfoamed porous stiff shells with integral foams for highly complex shapes offer an optimized trade-off between acoustic performance, weight and costs. A dedicated experimental set-up has been designed in order to measure both structureborne and airborne NVH performances of engine encapsulation insulators applied on an engine casing placed in a coupled reverberant / semi-anechoïc rooms

Duval, Arnaud, Crignon, Guillaume, Goret, Mickael, lei, Lei, Wilkinson, Alexandre, Dauchez, Nicolas, POLAC, Laurent

Application of a Seat Transmissibility Approach to Experience Measured or Predicted Seat-rail Vibration in a Multi-Attribute Simulator

2024-01-2962To be published on 06/12/2024

Computer modelling, virtual prototyping and simulation is widely used in the automotive industry to optimize the development process. While the use of CAE is widespread, on its own it lacks the ability to provide observable acoustics or tactile vibrations for decision makers to assess, and hence optimize the customer experience. Subjective assessment using Driver-in-Loop simulators to experience data has been shown to improve the quality of vehicles and reduce development time and uncertainty. Efficient development processes require a seamless interface from detailed CAE simulation to subjective evaluations suitable for high level decision makers. In the context of perceived vehicle vibration, the need for a bridge between complex CAE data and realistic subjective evaluation of tactile response is most compelling. A suite of VI-grade noise and vibration simulators have been developed to meet this challenge. In the process of developing these solutions VI-Grade has identified the need

Franks, Graham, Tcherniak, Dmitri, Kennings, Paul, Allman-Ward, Mark, Kuhmann, Marvin

New Equivalent Static Load (ESL) Creation Procedure for Complete Vehicle

2024-01-2944To be published on 06/12/2024

By analyzing the dynamic distortion in all body closure openings in a complete vehicle, a better understanding of the body characteristics can be achieved compared to traditional static load cases such as static torsional body stiffness. This is particularly relevant for non-traditional vehicle layouts and electric vehicle architectures. The body response is measured with the so-called Multi Stethoscope (MSS) when driving a vehicle on a rough pavé road (cobble stone). The MSS is measuring the distortion in each opening in two diagonals. During the virtual development, the distortion is described by the relative displacement in diagonal direction in time domain using a modal transient analysis. The results are shown as Opening Distortion Fingerprint ODF and used as assessment criteria within Solidity and Perceived Quality. By applying the Principal Component Analysis (PCA) on the time history of the distortion, a Dominant Distortion Pattern (DDP) can be identified. The DDP means that

Weber, Jens, Luiz Felipe, Faria Ricardo, Bäcklund, Jesper, Vignati, Michele, Cheli, Federico

Synergizing Efficiency and Silence: A Novel Approach to E-Machine Development

2024-01-2914To be published on 06/12/2024

Traditionally, Electric Machine design has primarily focused on factors like efficiency, packaging, and cost, often neglecting the critical aspects of Noise, Vibration, and Harshness (NVH) in the early decision-making stages. This disconnect between E-Machine design teams and NVH teams has consistently posed a challenge. This paper introduces an innovative workflow that unifies these previously separate domains, facilitating comprehensive optimization by seamlessly integrating NVH considerations with other E-Machine objectives, such as electromagnetic compatibility (EMC). This paper highlights AVL's approach in achieving this transformation and demonstrates how this integrated approach sets a new standard for E-Machine design. The presented approach relies on AI-driven algorithms and computational tools. This advanced methodology harnesses the power of AI for predictive modeling and advanced optimization, resulting in the development of the optimal E-Machine for NVH without

Mehrgou, Mehdi, Garcia de Madinabeitia, Inigo, Ahmed, Mohamed Essam

Making modal analysis easy and more reliable – Reference points identification by experimental prestudy

2024-01-2931To be published on 06/12/2024

Though modal analysis is a common tool to evaluate the dynamic properties of a structure, there are still many individual decisions to be made during the process which are often based on experience and make it difficult for occasional users to gain reliable and correct results. One of those experience-based choices is the correct number and placement of reference points. This decision is especially important, because it must be made right in the beginning of the process and a wrong choice is only noticeable in the very end of the process. Picking the wrong reference points could result in incomplete modal analysis outcomes, as it might make certain modes undetectable, compounded by the user's lack of awareness about these missing modes. In the paper an innovative approach will be presented to choose the minimal number of mandatory reference points and their placement. While other approaches use results of numerical simulations or rely on a visual evaluation of measurement data by the

Kamper, Tim, Beljan, Denis, Brücher, Haiko, Wegerhoff, Matthias

Electric Vehicle Ride & Vibrations Analysis - Full electric vehicle MBD model development for NVH studies

2024-01-2918To be published on 06/12/2024

The NVH performance of electric vehicles is a key indicator of vehicle quality, being the structure-borne transmission predominating at low frequencies. Many issues are typically generated by high vibrations, transmitted through different paths, and then radiated acoustically into the cabin. A combined analysis, with both finite-element and multi-body models, enables to predict the interior vehicle noise and vibration earlier in the development phases, to reduce the development time and moreover to optimize components with an increased efficiency level. In the present work, a simulation of a Hyundai electric vehicle has been performed in IDIADA VPG with a full vehicle multibody (MBD) model, followed by vibration/acoustic simulations with a Finite elements model (FEM) in MSC. Nastran to analyze the comfort. Firstly, a full vehicle MBD model has been developed in MSC. ADAMS/Car including representative flexible bodies (generated from FEM part models). The usage of a physical tire model

Tonelli, Riccardo, Buckert, Sebastian, Patrucco, Andrea, Bragado Perez, Beatriz, Gutierrez, Javier, Sanchez, Angel

Simulation and test methods on NVH performance of axle system

2024-01-2950To be published on 06/12/2024

For electric vehicles, road noise, together with wind noise, is the most important contributor for vehicle interior noise. Road noise is very dependent on the NVH behavior of axle system including wheels and tires. Axle system is part of vehicle platform which should be compatible with different body variants. Therefore, il is important to characterize the NVH performance of an axle system independently of car body structure, so that the design the axle can be optimized at the early stage according to the global requirements of all the related vehicles. The best way to characterize the NVH performance of an axle system is to measure the blocked forces on an appropriate test rig. However, the measurement of blocked forces from an axle system requires very stiff boundary conditions which is difficult to achieve in practice. For axles with rigid mountings, it is nearly impossible to measure the blocked forces on test rig. Due to the presence of numerous joints and metallic structures, the

Wang, Shanjin, Gagiu, Constantin

The use of machine learning algorithms in the simulation of multi-layer acoustic palliatives

2024-01-2928To be published on 06/12/2024

Acoustic palliatives used in the automotive industry have evolved from simple felt and heavy layer combinations into highly complex formulations and combinations to account for higher performance targets, lower weight and inevitably cost constraints. Achieving Customer performance compliance usually involves a time-consuming exercise of material characterisation and measurement. Ideally this should be carried out via simulation, but as material mixtures and compositions become more complex, the ability to accurately simulate their acoustic performance is becoming increasingly difficult. Historically, Biot parameters and their associated TMM models have been used to simulate the acoustic performance of multi-layer material compositions. However, these simulations are not able to account for real-world complexities such as manufacturing imperfections or inter-layer gluing effects. The assumptions made by simulation models, such as a perfectly diffuse field, are rarely true in actual

Harry, Evan, Morris-Kirby, Rod, Caponio, Eleonora, Hoang, Minh Tan

Fuel Cell Fault Simulation and Detection for On Board Diagnostics using Real-Time Digital Twins

2024-37-0014To be published on 06/12/2024

The modern automotive industry is facing challenges of ever-increasing complexity in the electrified powertrain era. On-board diagnostic (OBD) systems must be thoroughly validated and calibrated through many iterations to function effectively and meet the regulation standards. Their development and design process are more complex when prototype hardware is not available and therefore virtual testing is a prominent solution, including Software-in-the-loop (SiL) and Hardware-in-the-loop (HIL) simulations. Virtual prototype testing relying on real-time simulation models is necessary to design and test new era’s OBD systems quickly and in scale. The new fuel cell powertrain involves new and preciously unexplored fail modes. To make the system robust, simulations are required to be carried out to identify different fails. Thus, it is imminent to build simulation models which can reliably reproduce failures of components like the compressor, recirculation pump, humidifier or cooling systems

Pandit, Harshad Rajendra, Dimitrakopoulos, Pantelis, Shenoy, Manish, Altenhofen, Christian

Structural Dynamic Modelling of HVAC Systems

2024-01-2923To be published on 06/12/2024

The structure-, fluid- and air-borne excitation generated by HVAC compressors can lead to annoying noise and low frequency vibrations in the passenger compartment. These noises and vibrations are of great interest in order to maintain high passenger comfort of EV vehicles. The main objective of this paper is to develop a numerical model of the HVAC system and to simulate the structure-borne sound transmission from the compressor through the HVAC hoses to the vehicle in a frequency range up to 1 kHz. An existing automotive HVAC system was fully replicated in the laboratory. Vibration levels were measured on the compressor and on the car body side of the hoses under different operational conditions. Additional measurements were carried out using external excitation of the compressor in order to distinguish between structure- and fluid-borne transmission. The hoses were experimentally characterised with regard to their structure-borne sound transmission characteristics. Strong temperature

Buchegger, Blasius, Sonnberger, Pius, Böhler, Elmar, Nijman, Eugene, Rejlek, Jan, Billermann, Robert, Krüger, Yannik

Comparing the NVH behaviour of an innovative steel-wood hybrid battery housing design to an all aluminium design

2024-01-2949To be published on 06/12/2024

The production of electric vehicles (EVs) has a significant environmental impact, with up to 50 % of their lifetime greenhouse gas potential attributed to manufacturing processes. The use of sustainable materials in EV design is therefore crucial for reducing their overall carbon footprint. Wood laminates have emerged as a promising alternative due to their renewable nature. Additionally, wood-based materials offer unique damping properties that can contribute to improved Noise, Vibration, and Harshness (NVH) characteristics. In comparison to conventional materials such as aluminum, ply wood structures exhibit beneficial damping properties. The loss factor of plywood structures with a thickness below 20 mm ranges from 0.013 to 0.032. Comparable aluminum structures however exhibit only a fraction of this loss factor with a range between 0.002 and 0.005. In this study, the potential of lightweight wood composites, specifically steel-wood hybrid structures, is investigated in the design

Wagner, Markus, Baumann, Georg, Lindbichler, Lukas, Klanner, Michael, Feist, Florian

Advance simulation method for aero-acoustic vehicle design

2024-01-2938To be published on 06/12/2024

With the electrification of powertrains, the noise level inside vehicles reach high levels of silence. The dominant engine noise found in traditional vehicles is now replaced by other sources of noise such as rolling noise and aeroacoustic noise. These noises are encountered during driving on roads and highways and can cause significant fatigue during long journeys. Regarding aeroacoustic phenomena, the noise transmitted into the cabin is the result of both turbulent pressure and acoustic pressure created by the airflow. Even though it is lower in level, the acoustic pressure induces most of the noise perceived by the occupants. Its wavelength is closer to the characteristic vibration wavelengths of the glass, making its propagation more efficient through the vehicle's windows. The accurate modeling of these phenomena requires the coupling of high-frequency computational fluid dynamics (CFD) simulations and vibro-acoustic simulations. CFD simulations must reproduce the creation and

Mordillat, Philippe, Zerrad, Mehdi, Errico, Fabrizio

Gaussian Process Surrogate Models for Vibroacoustic Simulations

2024-01-2930To be published on 06/12/2024

In vehicle NVH development, vibroacoustic simulations with Finite Element (FE) models are a common technique. The computational costs for these calculations are steadily rising due to more detailed modelling and higher frequency ranges. At the same time, the need for multiple evaluations of the same model with different input parameters, e.g., for uncertainty quantification, optimization, or robustness investigations, is also increasing. Therefore, it is crucial to reduce the computational costs in these cases. A common technique is to use surrogate models that replace the computationally intensive FE model to perform repeated evaluations. Several different methods in this area are well established, but with the continuous advancements in the field of machine learning, interesting new methods like the Gaussian Process (GP) regression arises as a promising approach. In Gaussian process regression, the model response is expressed as a stochastic process with a user-defined kernel

Luegmair, Marinus, Dantas, Rafaella, Schneider, Felix, Müller, Gerhard

Design of a Decentralized Control Strategy for CACC Systems accounting for Uncertainties

2024-37-0010To be published on 06/12/2024

Traditional CACC systems utilize inter-vehicle wireless communication to maintain minimal yet safe inter-vehicle distances, thereby improving traffic efficiency. However, introducing communication delays generates system uncertainties that jeopardize string stability, a crucial requirement for robust CACC performance. To address these issues, we introduce a decentralized Model Predictive Control (MPC) approach that incorporates Kalman Filters and state predictors to counteract the uncertainties posed by noise and communication delays. We validate our approach through MATLAB Simulink simulations, using stochastic and mathematical models to capture vehicular dynamics, Wi-Fi communication errors, and sensor noises. In addition, we explore the application of a Reinforcement Learning (RL)-based algorithm to compare its merits and limitations against our decentralized MPC controller, considering factors like feasibility and reliability

Seifoddini, Arash, Azad, Arefeh, Musa, Alessia, Misul, Daniela

A Numerical Study of the Laminar Flame Speed of Hydrogen/Ammonia Mixtures under Engine-like Conditions

2024-37-0020To be published on 06/12/2024

In the effort to achieve the goal of a climate-neutral transportation system, the use of hydrogen and other synthetic fuels plays a key role. As battery electric vehicles become more widespread, e-fuels could be used to defossilize the hard-to-electrify transportation sectors and to store energy produced from renewable and non-continuous energy sources. Among e-fuels, hydrogen and ammonia are very attractive because they are carbon-neutral and their oxidation does not lead to any CO2 emissions. Furthermore, hydrogen/ammonia mixtures overcome the issues that arise as each of the two fuels is separately used. In the automotive sector, the use of either hydrogen, ammonia or their blends require a characterization of such mixtures under engine-like conditions, that is, at high pressures and temperatures. The aim of this work is to evaluate the Laminar Flame Speed (LFS) of hydrogen/ammonia mixtures by varying the thermodynamic conditions and the molar composition of the reactants. The

Bochicchio, Flavio, D'Amato, Marco, Magi, Vinicio, Viggiano, Annarita

Reduced order model for modal analysis of electric motors considering material and dimensional variations

2024-01-2945To be published on 06/12/2024

With the electrification of the automotive industry, electric motors have emerged as pivotal components. A profound understanding of their vibrational behaviour stands as a cornerstone for guaranteeing not only the optimal performance and reliability of vehicles in terms of noise, vibration, and harshness (NVH), but also the overall driving experience. The use of conventional finite element analysis (FEA) techniques for identification of the natural frequencies characteristics of electric motors often imposes significant computational loads, particularly when accurate material and geometrical properties and wider frequency ranges are considered. On the other hand, traditional reduced order vibroacoustic methodologies utilising simplified 2D representations, introduce several assumptions regarding boundary conditions and properties, leading to sacrifices in the accuracy of the results. To address these limitations, this study presents a novel electric motor modal analysis approach by

Andreou, Panagiotis, Theodossiades, Stephanos, Hajjaj, Amal Z., Mohammadpour, Mahdi, Ricardo Souza, Marcos

Estimating a Viscous Damping Model for a Vibrating Panel in contact with an Acoustic Trim Enhanced with Particle Dampers

2024-01-2917To be published on 06/12/2024

Dampers (PDs) are passive devices employed in vibration and noise control applications. They consist of a cavity filled with particles that, when fixed to a vibrating structure, dissipate vibrational energy through friction and collisions among the particles. These devices have been extensively documented in the literature and find widespread use in reducing vibrations in structural machinery components subjected to significant dynamic loads during operation. However, their application in reducing vehicle interior sound has received, up to now, relatively little attention. Previous work by the authors has proven the effectiveness of particle dampers in mitigating vibrations in vehicle body panels, achieving a notable reduction in structure-borne noise within the vehicle cabin with an additional weight comparable to or even lower than that of bituminous damping treatments traditionally used for this purpose. This effect may be obtained also by integrating PDs into the B-side of NVH trim

Sanchez Climent, Francisco Vicente, Bertolini, Claudio

Bushing Stiffness Optimization Method for NVH Improvement Using Blocked Force and Energy-Based Index in Suspension System

2024-01-2921To be published on 06/12/2024

Reductions in powertrain noise have led to an increased proportion of road noise, prompting various studies aimed at mitigating it. Road excitation primarily traverses through the vehicle suspension system, necessitating careful optimization of the characteristics of bushings at connection points. However, optimizing at the vehicle assembly stage is both time-consuming and costly. Therefore, it is essential to proceed with optimization at the subsystem level using appropriate objective functions. In this study, the blocked force and energy-based index derived from complex power were used to optimize the NVH performance. Calculating the complex power in each bushing enables computing the power flow, thereby providing a basis for evaluating the NVH performance. Through stiffness injection, the frequency response functions (FRF) of the system can be predicted according to arbitrary changes in the bushing stiffness. Based on this, the blocked force and the energy-based index can be

Oh, Jun Young, Song, David, Cho, Munhwan, Ih, Kang-Duck, Kang, Yeon June

Frequency-based substructuring for virtual prediction and uncertainty quantification of thin-walled vehicle seat structures

2024-01-2946To be published on 06/12/2024

Finite element simulation (FE) makes it possible to analyze the structural dynamic behavior of vehicle seat structures in early design phases to meet Noise-Vibration-Harshness (NVH) requirements. For this purpose, linear simulations are usually used, which neglect many nonlinear mechanical properties of the real structure. These models are trimmed to fit global vibration behavior based on the complex description of contact or jointed definitions. Targeted design is therefore only possible to a limited extent. The aim of this work is to characterize the entire seat structure and its sub-components in order to identify the main contributors using experimental and simulative data. The Lagrange Multiplier Frequency Based Substructuring (LM-FBS) method is used for this purpose. Therefore, the individual subsystems of seat frame, seat backrest and headrest are characterized under different conditions. Furthermore, the complex connection interface is discretized by means of a high-resolution

Wagner, Philipp, Langer, Patrick, Mäder, Marcus, Marburg, Steffen

The irrotational intensity: an efficient tool to understand the vibration energy propagation in complex structures using an FE Model

2024-01-2942To be published on 06/12/2024

Although structural intensity was introduced in the 80's, this concept never found practical applications, neither for numerical nor experimental approaches. Quickly, it has been pointed out that only the irrotational component of the intensity offers an easy interpretation of the dynamic behavior of structures by visualizing the vibration energy flow. This is especially valuable at mid and high frequency where the structure response understanding can be challenging. A new methodolodgy is proposed in order to extract this irrotational intensity field from the Finite Element Model of assembled structures such as Bodies In White. This methodology is hybrid in the sense that it employs two distinct solvers: a dynamic solver to compute the structural dynamic response and a thermal solver to address a diffusion equation analogous to the thermal conduction built from the previous dynamic response. The field separation is based on the Helmholtz-Hodge theorem, that ensures the computations

Gagliardini, Laurent, Takhchi, Jamal, Sadoulet-reboul, Emeline, Ouisse, Morvan, Bornet, Frederic

Coupled Boundary Element and Poro-Elastic Element Simulation Approach to Designing Effective Acoustic Encapsulation for Vehicle Components

2024-01-2956To be published on 06/12/2024

To meet vehicle interior noise targets and expectations, components including those related to electric vehicles (EVs) can effectively be treated at the source with an encapsulation approach, preventing acoustic and vibration sources from propagating through multiple paths into the vehicle interior. Encapsulation can be especially useful when dealing with tonal noise sources in EVs which are common for electrical components. These treatments involve materials that block noise and vibration at its source but add weight and cost to vehicles – optimization and ensuring the material used is minimized but efficient in reducing noise everywhere where it is applied is critically important. Testing is important to confirm source levels and verify performance of some proposed configurations, but ideal encapsulation treatments are complex and cannot be efficiently achieved by trial-and-error testing. Simulation is a key supporting tool to guide location, thickness, and properties of

Van Hal, Willem, Goy, Oliver, Amichi, Kamel, Musser, Chadwyck, Calloni, Massimiliano, Hadjit, Rabah

A Finite-Element-Simulation Workflow to Investigate the Aero- and Vibro-Acoustic Signature of an Enclosed Centrifugal Fan

2024-01-2940To be published on 06/12/2024

Centrifugal fans are applied in many industrial and civil applications, such as manufacturing processes and building HVAC systems. They can also be found in automotive applications. Noise-reduction mea- sures for centrifugal fans are often challenging to establish, as acous- tic performance may be considered a tertiary purchase criterion after energetic efficiency and price. Nonetheless, their versatile application raises the demand for noise control. In a low-Mach-number centrifugal fan, acoustic waves are predominantly excited by aerodynamic fluctu- ations in the flow field and transmit to the exterior via the housing and duct walls. The scientific literature documents numerous mech- anisms that cause flow-induced sound generation, even though only some are considered well-understood. Numerical simulation methods are widely used to gather spatially high-resolved insights into physical fields. However, for a centrifugal fan, the numerical simulation of the coupled aero- and

Heidegger, Patrick, Czwielong, Felix, Schoder, Stefan, Becker, Stefan, Kaltenbacher, Manfred

A critical review of some Panel Contribution Analysis methods used in interior vehicle acoustics

2024-01-2932To be published on 06/12/2024

In the acoustic study of the interior noise of a vehicle, whether for structure-borne or air-borne excitations, knowing which areas contribute the most to interior noise and therefore should be treated as a priority, is the main goal of the engineer in charge of the NVH. Very often these areas are numerous, located in different regions of the vehicle and contribute at different frequencies to the overall sound pressure level. This has led to the development of several “Panel Contribution Analysis” (PCA) experimental techniques. For example, a well-known technique is the masking technique, which consists of applying a “maximum package” (i.e., a package with very high sound insulation) to the panels outside of the area whose contribution has to be measured. This technique is pragmatic but rather cumbersome to implement. In addition, it significantly modifies the dynamics and internal acoustics of the vehicle. In another well-known technique, the contribution of a certain area is defined

Di Marco, Federico, Lafont, Thibault, Bertolini, Claudio, Gerges, Youssef

Acceleration of Fast-SCR Reactions by Eliminating “The Ammonia Blocking Effect

2024-37-0001To be published on 06/12/2024

The recent and future trends of energy for heavy-duty vehicles are considered e-fuel, H2, and electricity, and the Selective Catalytic Reduction (SCR) system is necessary for achieving the goals of zero-emission internal combustion engines that use e-fuel and H2 as a fuel. The Japanese automotive industry uses a Cu-zeolite based SCR catalyst since Vanadium is designated as a specific chemical substance, which the Ministry of Environment prohibits its release into the atmosphere. This study attempted purification rate improvement by controlling the NH3 supply with a mini-reactor and by simulated exhaust gas. Specifically, the experiment was done by examining the effect of the pulse amplitude, frequency, and duty ratio on the purification rate by supplying the NH3 pulse injection to the test piece Cu-chabazite catalyst. Additionally, the results of the reactor experiment were validated by numerical simulation considering the detailed surface reaction processes on the catalyst. The

Morita, Daiki, Kotani, Yuya, Zu, Qiuyue, Yoshida, Fuka, Sok, Ratnak, Kusaka, Jin

Definition and Application of a Target Cascading Process on a Fully Trimmed Body, from Vehicle Objectives to Component Objectives

2024-01-2916To be published on 06/12/2024

Finite element (FE) based simulations for fully trimmed bodies are a key tool in the automotive industry to predict and understand the Noise, Vibration and Harshness (NVH) behavior of a complete car. While structural and acoustic transfer functions are nowadays straight-forward to obtain from such models, the comprehensive understanding of the intrinsic behavior of the complete car is more complex to achieve, in particular when it comes to the contribution of each sub-part to the global response. This paper proposes a complete target cascading process, which first assesses which sub-part of the car is the most contributing to the interior noise, then decomposes the total structure-borne acoustic transfer function into several intermediate transfer functions, allowing to better understand the effect of local design changes. This transfer functions decomposition opens the door to cascading full-vehicle objectives, which typically consists of achieving a maximal noise level in the cabin

de Walque, Cyril, Yoo, Ji Woo, Jeong, ChanHee, Kong, Taesik

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