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Direction Specific Analysis of Psychoacoustics Parameters Inside Car Cockpits: a Novel Tool for NVH and Sound Quality

University of Parma-Daniel Pinardi, Costante Belicchi, Angelo Farina, Marco Binelli
University of Parma / ASK Industries SpA-Lorenzo Ebri
  • Technical Paper
  • 2020-01-1547
To be published on 2020-06-03 by SAE International in United States
Psychoacoustics parameters are widely employed in automotive field for objective evaluation of Sound Quality of vehicle cabins and their components. The standard approach relies on binaural recordings from which numerical values and curves are calculated and head-locked binaural listening playback can be performed. Recently, the Virtual Reality technology started to diffuse also in automotive field, bringing new possibilities for enhanced and immersive listening sessions. In this paper, we combine both solutions: the VR approach is adopted to calculate the principal psychoacoustics parameters. The acquisition system consists in a massive spherical microphone array featuring a camera for recording panoramic visual background. The acoustical information is encoded into High Order Ambisonics spatial format, that can be rendered on stereoscopic visors and Spatial PCM Sampling format that can be used to produce 360° colour maps. In this way, we are able to plot the psychoacoustics parameters adding their directivity information over the panoramic background, turning the array into a novel 360° diagnostic tool. At the same time, the playback can be performed inside Ambisonics listening rooms or binaurally…
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Improvement of Tightening Reliability of Bolted Joints Using Elliptical Confidence Limit in Calibrated Wrench Method

Tokyo Metropolitan University-Soichi Hareyama, Ken-ichi Manabe, Satoshi Kobayashi
  • Technical Paper
  • 2020-01-0218
To be published on 2020-04-14 by SAE International in United States
The calibrated wrench method is used in the tightening of bolts in manufacturing industries in the case of a large amount of tightening work. It is important to apply a large initial clamping force to ensure tightening reliability and prevent self-loosening, fatigue breakage, and so forth. In this method, the clamping force of bolted joints is controlled using a torque wrench. However, since the clamping force is indirectly applied by a wrench, it varies greatly in the case of a large amount of tightening in a factory. Therefore, the calibrated wrench method is not so accurate from the viewpoint of clamping force control. It is conventionally thought that the distribution of the clamping force has the shape of a rhombus. When tightening torque and clamping force are considered to be two independent random variables, the clamping force is distributed within an elliptical confidence limit. Here, we show that the distribution of equivalent stress also has an elliptical confidence limit. Considering the permitted limit for working load stress on a bolted joint, the elliptical distribution has…
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A Performance Measurement and Analysis Method for Infotainment System

Hyundai Motor Company-Peace Lee
  • Technical Paper
  • 2020-01-1347
To be published on 2020-04-14 by SAE International in United States
The car infotainment system provides various functions such as navigation, DMB, and external device interworking. In the future, complex new technologies such as remote diagnosis and control, V2X communication, integrated display, and autonomous driving interworking should be reflected. Also, even after mass production, such as smartphones, software must be constantly updated to apply bug fixes and new functions. However, as the internal software modules work together in a complicated way, system performance problems tend to occur due to changes in the software, and if they are not managed from the development stage, more costs must be paid for improvement over time. Moreover, after mass production, the scope of improvement will be limited. Therefore, software must be verified and optimized from time to time to ensure system performance quality from the minimum development process. Generally, various tools are used to verify software performance. Currently, top, perf, strace, gdb, DLT, and bootchart are mainly used on Linux-based platforms. In addition, there is a lack of intuitive statistical information to analyze and judge the overall performance of the…
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Hybrid Powertrain Choices for Emerging Engine Technologies

Aramco Research Center-Vincent Costanzo
Argonne National Laboratory-Ram Vijayagopal, Daniela Nieto Prada
  • Technical Paper
  • 2020-01-0440
To be published on 2020-04-14 by SAE International in United States
US department of energy estimates the peak efficiency of a modern spark ignited naturally aspirated Otto cycle engine to be 36%. Atkinson cycle engines are estimated to get 40% peak efficiency. Most engines can achieve this peak efficiency only for a limited operating region. Hybrid powertrains enable engine to operate in this efficiently. Overall efficiency is improved by shutting down engine during idle events and by adjusting the operating speed and load on the engine using electric machines. The choice of the powertrain and component sizes depends on the engine characteristics, drive cycles and vehicle technical requirements. This study examines what type of powertrains will be suitable for more efficient engines that are likely to be available in the near future. Some of these technologies achieve higher efficiency with a trade off on power or by accepting a more restrictive operating region. An appropriate powertrain choice can still enable such an engine to be a viable option for an automobile. Using simulation tools, 14 different engine technologies are evaluated in this paper for their fuel…
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A Smart Measuring System for Vehicle Dynamics Testing

Politecnico di Torino-Enrico Galvagno, Stefano Mauro, Stefano Pastorelli, Antonio Tota
  • Technical Paper
  • 2020-01-1066
To be published on 2020-04-14 by SAE International in United States
A fast measurement of the car handling performance is highly desirable to easily compare and assess different car setup, e.g. tires size and supplier, suspension settings, etc. Instead of the expensive professional equipment normally used by car manufacturers for vehicle testing, the authors propose a low cost solution that is nevertheless accurate enough for comparative evaluations. The paper presents a novel measuring system for vehicle dynamics analysis, which is based uniquely on the sensors embedded in a smartphone and completely independent on the signals available through vehicle CAN bus. Data from tri-axial accelerometer, gyroscope, GPS and camera are jointly used to compute the typical quantities analyzed in vehicle dynamics applications. In addition to signals like yaw rate, lateral and longitudinal acceleration, vehicle speed and trajectory, normally available when working with Inertial Measurement Units (IMU) equipped with GPS, in the present application also the steering wheel angle is measured by artificial vision algorithms that use the phone camera.. The latter signal, besides being important for identifying the maneuver imposed by the driver, it enables the usage…
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Application of Multivariate Control Chart Techniques to Identifying Nonconforming Pallets in Automotive Assembly Plants

FCA US LLC-Michael Huang, Yuqin Wang
University of Texas at San Antonio-Adel Alaeddini
  • Technical Paper
  • 2020-01-0477
To be published on 2020-04-14 by SAE International in United States
The Hotelling multivariate control chart and the sample generalized variance |S| are used to monitor the mean and dispersion of underbody data including the pallet information to identify the non-conforming pallets. An iterative procedure and the Gaussian mixture model (GMM) are used to rank the non-conforming pallets in the order of severity. The multivariate Hotelling T^2 test statistic with Mason-Tracy-Young (MYT) signal decomposition method are used to identify the features that are affected by the non-conforming pallets. These algorithms were implemented in Advanced Pallet Analysis module of FCA Body Shop Analysis Tool (BSAT). The identified non-conforming pallets are displayed in a scatter plot with different color for each pallet. The run chart of an affected feature confirms the nonconforming pallets by highlighting data points from the nonconforming pallet. The analysis module has been successfully used in the body shops of FCA plants. One example is presented to demonstrate the application.
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Design of the powder metal shift fork and sleeve

Czech Technical University-Gabriela Achtenova, Jiri Pakosta
  • Technical Paper
  • 2020-01-1322
To be published on 2020-04-14 by SAE International in United States
The paper will present the design of shift fork for automotive manual gearbox dedicated for the manufacturing with help of powder metal technology. Based on limitations and requirements of new production technology of shifting sleeve, a new prototype of shifting sleeve is created, for which are new shifting forks then designed. The form of the prototype of the shift sleeve respected the requirements of the new technology, but from cost reason, it was manufactured from steel. The shift fork was changed accordingly to the new form of the shift sleeve. The functionality of several forks with different tolerances was tested. Prototypes were put through functional and durability tests on testing bench in real automotive gearbox. The test were accomplished on the inertia test stand. Drawings and CAD models of tested prototypes, custom tools and designed shift forks will be described.
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Improved Customer Experience through Electric Vehicle Sound Enhancement

General Motors LLC-Frank Valeri, Glenn Pietila
  • Technical Paper
  • 2020-01-1361
To be published on 2020-04-14 by SAE International in United States
Electric Vehicles are typically thought of as being quiet and refined, but they do come with some unique N&V challenges. Some of these challenges include a natural sound that can be undesirable due to its tonal nature, presence of high frequency, discontinuities in sound, and characteristics and levels that do not always naturally increase with motor torque and vehicle speed. One approach to address those challenges is Electric Vehicle Sound Enhancement (EVSE) which is a software feature embedded within the infotainment system. EVSE can be used to improve the perception of the vehicle by enhancing the preferred natural sounds of the vehicle, masking unusual and annoying components of the sound and aurally conveying information related to the vehicle performance. A jury study was conducted to better understand how EVSE can be used to accomplish this. This paper will summarize a typical EVSE system and highlight some of the tools and methods that can be used to develop an EVSE tuning that mitigates unpleasant sounds while enhancing the customer experience without completely changing the vehicle DNA.…
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A study on optimization of the cross-section of door impact beam for weight reduction

Hyundai Motor Company-Heejin Im
  • Technical Paper
  • 2020-01-0631
To be published on 2020-04-14 by SAE International in United States
This paper focuses on the optimization of the cross section of a member type impact door beam. The cross section of the beam was parameterized by using a geometry morphing tool FCM(Fast Concept Modeler) which plug in CATIA, and the metamodel of FE analysis results was created and optimized by LS-OPT. The ANOVA analysis of results was performed to find the factor of weight reduction. And then a new cross section concept was proposed to overcome the limitation of old structure. The proposed cross section was optimized to obtain the final cross section which has a weight reduction of 10% or more.
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A Preliminary Method of Delivering Engineering Design Heuristics

Clemson University-Mohammad M. Hussain, Christiaan Paredis
  • Technical Paper
  • 2020-01-0741
To be published on 2020-04-14 by SAE International in United States
This paper argues the importance of engineering heuristics and introduces an educational data-driven tool to help novice engineers develop their engineering heuristics more effectively. The main objective in engineering practice is to identify opportunities for improvement and apply methods to effect change. Engineers do so by applying ‘how to’ knowledge to make decisions and take actions. This ‘how to’ knowledge is encoded in engineering heuristics.In this paper, we describe a tool that aims to provide heuristic knowledge to users by giving them insight into heuristics applied by experts in similar situations. A repository of automotive data is transformed into a tool with powerful search and data visualization functionalities. The tool can be used to educate novice automotive engineers alongside the current resource intensive practices of teaching engineering heuristics through social methods such as an apprenticeship. The tool can do so by providing novices with powerful search and data visualization capabilities which will allow them to understand tradeoffs between vehicle attributes, to make assumptions from initial information, and to benchmark the vehicle design.