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Reduction of the Effect of the Creep Groan Brake Excitation in a Comercial Vehicle

IDIADA Automotive Technology SA-Angel Sanchez
  • Technical Paper
  • 2020-01-1530
To be published on 2020-06-03 by SAE International in United States
One of the results generated by the stick-slip intermittent motion of a brake at the friction interface is the Creep Groan Noise which is a low frequency self-excited vibration, normally less than 220 Hz. This local vibration generated between the brake couple, is transmitted through the suspension system until the passengers of the vehicle in form of vibration and noise. This paper presents a methodology that combines testing and numerical models in order to 1) detect the source of the Creep Groan, 2) create a correlated numerical model and 3) produce countermeasures that reduce the amplitude of the noise at occupant positions. The vehicle under investigation was a commercial vehicle employing air-actuated brake drums. From testing, global vehicles modes and displacements under operational conditions were respectively investigated by means of Operational Deflection Shapes and Real Time Animation. These techniques allowed to prove the existence of a feedback loop with a positive gain that excites a suspension resonance mode, creating an unstable shaking effect in the whole vehicle. In-service data suggest that the brake actuation system…
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A Diagnostic Technology of Powertrain Parts that Cause Abnormal Noises using Artificial Intelligence

Hanyang University-Kyoungjin Noh, Joon-Hyuk Chang
Hyundai Motor Company-Insoo Jung, Dongchul Lee, Dongkyu Yoo, Kibeen Lim
  • Technical Paper
  • 2020-01-1565
To be published on 2020-06-03 by SAE International in United States
In general, when a problem occurs in a component, various phenomena appear, and abnormal noise is one of them. The service technicians diagnose the noise through the analysis using hearing and equipment. Depending on their experiences, the analysis time and diagnosis accuracy vary widely. The newly developed AI-based diagnostic technology diagnoses parts that cause abnormal noises within seconds when a noise is input to the equipment. To create a learning model for diagnosis, we collected as many abnormal noises as possible from various parts, and selected good and bad data. This process is very important in the development of diagnostic techniques. Artificial intelligence was learned by deep learning with selected good data. This paper is about the technology that can diagnose the abnormal noises generated from the engine, transmission, drivetrain and PE (Power Electric) parts of the eco-friendly vehicle through the diagnosis model composed of various methods of deep learning.
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Development of the Active Sound Generation Technology using Motor Driven Power Steering System

Hyundai Motor Co.-Kyoung-Jin Chang
Mdynamix AG-Leonhard Angerpointner, Dominik Schubert, Matthias Niegl
  • Technical Paper
  • 2020-01-1536
To be published on 2020-06-03 by SAE International in United States
As original engine sound is usually not enough to satisfy the driver’s desire for the sporty and fascinating sound, active noise control (ANC) and active sound design (ASD) have been great technologies in automobiles for a long time. However, these technologies which enhance the sound of vehicle using loud speakers or electromagnetic actuators etc. lead to the increase of cost and weight due to the use of external amplifier or external actuators. This paper presents a new technology of generating a target sound by the active control of a permanent magnet synchronous motor (PMSM) which is already mounted in vehicle. Firstly, an algorithm of this technology, called an active sound generation (ASG), is introduced with those signal conversion process, and then the high frequency noise issue and its countermeasure are presented. Secondly, ASG test bench is designed using a motor driven power steering (MDPS) system and then it is checked if ASG has any influence on an original function of MDPS. Thirdly, motor-induced vibration is measured in the transfer path and then the appropriate level…
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How Can Active Exhaust Systems Contribute to the Reduction of CO2 Emission and Comply with Future Pass-by Noise Limits?

Eberspaecher Exhaust Technology GmbH-Jan Krueger, Peter Wink, Maike Werner
  • Technical Paper
  • 2020-01-1534
To be published on 2020-06-03 by SAE International in United States
The pass-by noise limits of passenger vehicles according to ISO 362 / R51.3 will be further reduced by 2 dB in 2024 in Europe. Since the pass-by noise is substantially influenced by exhaust noise, the effort for the exhaust system needs to be increased. This results in systems with larger mufflers or higher backpressure. However, the more stringent CO2-emission targets require ever more efficient powertrains, which calls for rather lower backpressure to optimize the engine design. This paper describes, how compact active exhaust lines can support a design for low backpressure and high acoustic attenuation at the same time. For two passenger vehicle with gasoline engines, active exhaust lines are investigated in detail and the results are compared to the series production exhaust lines. Thus, in one exemplary case, the pass-by noise of a limousine could be reduced from 70 dB(A) to 68 dB(A) without any change in the vehicle design except the improved exhaust system.
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Development, System Integration and Experimental Investigation of an Active HVAC Noise Control System for a Passenger Car

Fraunhofer Institute LBF-Jonathan Millitzer, Valentin Mees, Christopher Ranisch
Hyundai Motor Company-Joong-Kwan Kim, Jinmo Lee, ChiSung Oh, Kang-Duck Ih
  • Technical Paper
  • 2020-01-1538
To be published on 2020-06-03 by SAE International in United States
Current developments in the automotive industry such as electrification and consistent lightweight construction increasingly enable the application of active control systems for the further reduction of noise in vehicles. As different stochastic noise sources such as rolling and wind noise as well as noise radiated by the ventilation system are becoming more noticeable and as passive measures for NVH optimization tend to be heavy and construction space intensive, current research activities focus on the active reduction of noise caused by the latter mentioned sources. This paper illustrates the development, implementation and experimental investigation of an active noise control system integrated into the ventilation duct system of a passenger car. Making use of a model-based design process, the development is based upon a holistic numerical simulation model integrating a reduced order acoustic model derived from finite element simulations as well as simplified loudspeaker and microphone characteristics. The numerical simulation assists the selection of a suitable loudspeaker microphone configuration, taking into account the available installation space and the integration of low-cost loudspeakers and MEMS microphones. The ventilation…
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Advance CAE Methods for NVH Development of High Speed Electric Axle

AVL LIST GmbH-Mehdi Mehrgou, Julian Pohn, Bernhard Graf, Christoph Priestner
AVL Software and Functions Gmbh-Mathias Deiml
  • Technical Paper
  • 2020-01-1501
To be published on 2020-06-03 by SAE International in United States
By developing more electric vehicles more and more focus are to the noise and vibration from Electric Drive unit. Here a high-speed E-axle for premium class vehicle is being developed up to 30,000 rpm, with high power density and lightweight design which introduce new challenges. Benchmarking of different E-axle and vehicles lead to targets which can be used at the begin of development as subsystem targets. This paper shows first how these targets like tonal noise can be simulated. Then the CAE method is used to optimize the source and structure to improve the NVH. Different aspects like torque ripple, electric whine, gears whine and mounting are discussed.
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Root Cause Analysis and Structural Optimization of E-Drive Transmission

AVL LIST GmbH-Thomas Resch
AVL-AST d.o.o.-Borislav Klarin, Ivan Grozdanovic, Denis Pevec
  • Technical Paper
  • 2020-01-1578
To be published on 2020-06-03 by SAE International in United States
We face a growing demand for so-called eAxles (electric axle drive) in vehicle development. An eAxle is a compact electric drive solution for full electric vehicles (and P4 hybrids) with integrated electric machine and transmission. The transmission can be rather simple using fixed gear with cylindrical gear steps but increasing demands on power and speed range as well as efficiency increase its complexity with planetary stages or switchable gear steps. Such an electro-mechanic system has different behavior than the classical ICE-driven powertrains, for example regarding NVH, where high frequency and tonal noise from gear whining and electro-magnetic excitation is an important comfort issue that needs to be understood and controlled. As knowledge base for such drives is currently low, development needs to be supported by methodologies, which are not only on high predictive level for NVH responses, but also allow a detailed understanding and insight into the causes and reasons of a certain behavior to identify noise effects and to accelerate learning for such systems. In addition, such methods should lead to the possibility to…
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Estimation the Interior Sound Quality in BEV's Regarding Measurements on the Roller Test Bench: Focusing on Tonal Omponents

AVL Deutschland GmbH-Daniel Schecker, Eugen Deisling, Peter Uerlings
  • Technical Paper
  • 2020-01-1542
To be published on 2020-06-03 by SAE International in United States
Development of BEVs gains more and more importance for OEMs, Tier 1s and DSPs and the project volumes continue to grow steadily. Even though the complexity of electric drive trains is reduced in comparison to combustion drive lines, the requirements for NVH development increases. Masking effects of noise through combustion noise fall away, the overall noise level decreases and the high frequency noises from the electric motors, inverters and transmissions dominate the overall impression of this new technology. Because of the missing combustion noise also noises like rolling noise from tires and wind noise is felt more and more disturbing for customers and pedestrians. The NVH character of any vehicle is highly dependent on its operating condition. With BEVs, it mainly depends on the vehicle speed, torque, temperature and state of charge of the battery. For this reason customers usually want to measure many speed-ups with constant torque steps. During a 3 Year cooperation with a big OEM almost all premium BEVs on the German market were measured/benchmarked to get a feedback about the own…
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Real-Time Capable Wind and Rolling Noise Synthesis for a More Realistic Vehicle Simulator Experience

Institute of Electronic Music & Acoustic-Julian Koch, Alois Sontacchi
MAGNA STEYR Fahrzeugtechnik AG & CO KG-Thorsten Bartosch, Werner Reinalter
  • Technical Paper
  • 2020-01-1546
To be published on 2020-06-03 by SAE International in United States
Nowadays a large proportion of the overall acoustic vehicle development takes place within virtual phases. Increasingly, projects require the auralization of virtual developed acoustics measures, e.g. from the disciplines of electro-acoustic, ride comfort, rolling noise or passive acoustic on dynamic or static driving simulators. In practice it turns out that in addition to engine noise also a realistic reproduction of rolling and wind noise is important. In this article, approaches to synthetic rolling and wind noise generators are discussed. We developed such real-time capable sound generators that are parametrizable according to arbitrary driving conditions. Furthermore, spacial reproduction of the driving sounds is achieved for binaural headphone, as well as for other arbitrary loudspeaker setups, like often found in driving simulators. Derived models and parametrization are based on measurements and recordings from several real vehicles. In order to facilitate the adjustment on specific vehicles and designing rolls thereof, the suggested parametrization is guided by a defined procedure. The influence of these noise components on an improved perception of the overall driving experience is objectified by means…
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Noise-Vibration (NVH) Analysis & Reduction in Traction Motors-PMSMs at the Design Stage

Tata Motors, Ltd.-Vishwanatha K. Rao
  • Technical Paper
  • 2020-01-1509
To be published on 2020-06-03 by SAE International in United States
Various electric propulsion systems are used in the industrial field. Recently, research focused on permanent magnet synchronous motors (PMSMs) because of their several advantages. There are various method to reduce Noise and Vibration of traction at the Design Stage of Motor. Noise reduction has constituted a difficult study point for the last years. A great part of this acoustic noise has electromagnetic origin. The harmonic spectrum of the PWM voltage supply is very rich and every frequency has direct effects on the motor acoustics and also Various Torques effect on the Motor, In this paper, the Design Stage of Electric Motor Describe the Design Specifications and Calculations For reduce Harmonics and unwanted Torque (Electromagnetic Forces) for NVH reduction. Such as two winding methods for the interior permanent-magnet synchronous motor for vehicle traction: concentrated winding and distributed winding. Both have merits and demerits, and both influences the motor’s performance. Also the paper presents and analyses the experimental acoustic noise of AC motors controlled by drives using different PWM techniques. Five criteria are taken into account: motor…