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High Speed Camera Based 3D Experimental Modal Analysis

University of Ljubljana-Domen Gorjup, Janko Slavic, Miha Boltezar
  • Technical Paper
  • 2020-01-1569
To be published on 2020-06-03 by SAE International in United States
High-speed camera systems in vibration measurements are typically limited to identifying motion perpendicular to the optical axis. Depth information, lost in the imaging process, can be recovered by using the recently introduced frequency domain triangulation and consequently full 3D deflection shapes can be obtained. This research presents the required theoretical background where the multiview image data is used for spatial small harmonic motion identification. Vibrations of an arbitrary-shaped specimen can be identified in the frequency domain using only a single, moving high-speed camera, extending the field-of-view of the established image-based vibration measurement methods. Real test cases are also presented.
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University Of Detroit Mercy-Mostafa Mehrabi
University Of Detroit Mercy-Jonathan Weaver
  • Technical Paper
  • 2020-01-0487
To be published on 2020-04-14 by SAE International in United States
performance and productivity. Tracking faults in a typical manufacturing system is inherently an inverse problem which makes it more challenging and difficult to solve. Presented in this article is the development of a new methodology for fault identification and root-cause analysis of complex assembly systems. A combination of a knowledge-based system and fuzzy set theory is used to develop this new technique, which is an intelligent system that mimics the behavior of an expert in the field, and can trace back the source(s) of the fault to the relevant station. Examples from real assembly operations are provided to show the effectiveness of this approach.
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Volume of Fluid vs. Cavitation CFD-Models to Calculate Drag Torque in Multi-Plate Clutches

SIMERICS GmbH-Rudi Niedenthal
Technical University of Munich-Daniel Groetsch, Katharina Voelkel, Hermann Pflaum, Karsten Stahl
  • Technical Paper
  • 2020-01-0495
To be published on 2020-04-14 by SAE International in United States
Wet running multi-plate clutches and brakes are important components of modern powershift gearboxes and industrial powertrains. In the open stage, drag losses occur due to fluid shear. Identification of drag losses is possible by experiment or CFD-simulation. For calculation of the complex fluid flow of an open clutch CFD-approaches such as the Volume of Fluid (VoF) method or the Singhal cavitation model are applicable. Every method has its own specific characteristics. This contribution sets up CFD-calculation models for different clutches with diverse groove designs. We present results of calculations in various operating conditions obtained from the Singhal cavitation model and the VoF-method. Despite the high spatial resolution of the calculation models the usage of a modern commercial CFD-solver and mesher (Simerics MP+) results in very short calculation times. The developed CFD-models consider the geometry of a complete clearance consisting of the friction plate, the gap between the plates, the steel plate and the flow conditions arising from the design of the inner and outer plate carrier. The full 360-degree modeling makes it possible to take…
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Noise Source Identification of a Gasoline Engine based on Parameters Optimized Variational Mode Decomposition and Robust Independent Component Analysis

Tianjin University-Xiao Yang, Fengrong Bi, Lipeng Zhang, Xiaobo Bi, Teng Ma, Daijie Tang
  • Technical Paper
  • 2020-01-0425
To be published on 2020-04-14 by SAE International in United States
Noise source identification and separation of internal combustion engines is an effective tool for engine NVH (noise, vibration and harshness) development. Among various experimental approaches, noise source identification using signal processing has attracted extensive attention because of that the signal can be easily acquired and the requirements for equipment is relatively low. In this paper, variational mode decomposition (VMD) combined with independent component analysis (ICA) is used for noise source identification of a turbo-charged gasoline engine. Existing algorithms have been proved to be effective to extract signal features but also have disadvantages. In this scheme, one of the key problems is that the main components of the signal, i.e. the main source of the noise, are unknown in advance. Thus the parameters selection of signal processing algorithms, which has a significance influence on the identification result, has no uniform criterion. To solve this problem, a parameter selection method is developed to optimize the decomposition level and the quadratic penalty of VMD. After the signal is decomposed into several relevant intrinsic mode functions (IMFs), ICA is…
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Empirical Study of the Braking Performance of Pedestrian Autonomous Emergency Braking (P-AEB)

Momentum Engineering Corp.-Omair Siddiqui, Nicholas Famiglietti, Benjamin Nguyen, Ryan Hoang, Jon Landerville
  • Technical Paper
  • 2020-01-0878
To be published on 2020-04-14 by SAE International in United States
Vehicle manufacturers are beginning to improve existing autonomous emergency braking (AEB) algorithms by pedestrian identification and avoidance capability. The Insurance Institute for Highway Safety (IIHS) has performed tests on eleven such vehicles; data is publicly available and was analyzed for this study. The IIHS tests were divided into three scenarios- 1) An adult pedestrian crossing a street on a path perpendicular to the travel line of vehicle, with a vehicle approach speed of 20 or 40 km/h, 2) a child pedestrian crossing a street from behind an obstruction on a path perpendicular to the travel line of a vehicle (approach speeds 20, 40 km/h), and 3) an adult pedestrian near the edge of a road in a path parallel to the travel path of a vehicle (approach speeds 40, 60 kph). An analysis was performed to compare Forward Collision Warning (FCW) engagement time, brake application time, and probability of impact across different manufacturers. It was observed that FCW on time for the 2019 Volvo XC40 lasted from 0.95 sec. - 2.36 sec., whereas for the…
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Optimization of Shifting Schedule of Vehicle Coasting Mode Based on Dynamic Mass Identification

Wuhan University of Technology-Boyang Zhang, Donghua Guo
  • Technical Paper
  • 2020-01-1321
To be published on 2020-04-14 by SAE International in United States
As an important vehicle state parameter, automotive mass has important reference value to the safety performance and comfort of automobiles. Current researches mostly focus on optimizing the established longitudinal dynamics model or improving the algorithm to reduce the recognition error. However, it often neglects that the longitudinal vibration caused by different driving speeds is very different, so the recognition rate is low under various complicated working conditions. In this paper, the speed decoupling model is firstly established to study the interference caused by the longitudinal vibration of the vehicle during the dynamic quality recognition. At the same time, the horizontal speed is decomposed from the combined speed. Then, several real vehicle tests are carried out at different gear speeds. The obtained gear speeds are decoupled and the results are brought into the longitudinal dynamics model. And the quality parameters are estimated by means of recursive least squares algorithm. The estimated value obtained is compared with the estimation result not be decoupled. The results show that the quality parameter estimates obtained by eliminating the longitudinal vehicle…
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Continuous integration as mandatory puzzle piece for the success of autonomous vehicles

iProcess LLC-Florian Rohde
  • Technical Paper
  • 2020-01-0087
To be published on 2020-04-14 by SAE International in United States
The transition to autonomous driving technology is is widely discussed topic today. In order to make autonomous vehicles work safely in the long run it will be a necessity to keep their software up to date at any time. Continuous integration methods need to get implemented into the automotive system development in order to keep up with the pace needed to make the new technology a success, and accepted by the users. With today’s traditional release methods vehicle updates are not deployed fast enough, a newly discovered corner case or glitch could restrict the usage of entire fleets for long time. In order to achieve turn around times measured in hours and not in weeks a sophisticated end to end continuous integration and validation process is needed on the highest system integration level. The development process has to contain smart branching strategies for fast turn around, it is mandatory to have a frozen and stable branch to release hotfixes in case of need, a validation branch with feature lock in order to stabilize, and a…
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Research on Passenger Car Driving Cycle with Multi-Source Data Fusion: Identification, Classification and Signal De-noising

The Technology Centre of Dongfeng Motor-Jun Yan, Jialei Xia
Wuhan University of Technology-Wei Zhou, Xuexun Guo, Xiaofei Pei, Zhenfu Chen
  • Technical Paper
  • 2020-01-1044
To be published on 2020-04-14 by SAE International in United States
Drivability plays a decisive role in evaluating vehicle performance, which directly affects the willingness of drivers and passengers to consume. In order to overcome the shortcomings of subjective evaluation due to expensive and time consuming. An objective evaluation system for passenger car driving cycle with multi-source data fusion is developed, which can be used to implement parameters acquisition, cycle identification, signal de-noising and feature value extraction. In this paper, recognition and classification of vehicle driving cycle and de-noising of acceleration signal are focused. First, the main parameters for objective driving performance evaluation are obtained by analyzing the vehicle transmission system model and the longitudinal dynamics theory. Then, the characteristics of the objective parameters of the specific working conditions and the expert knowledge base are combined, the sliding window method is adopted, and the identification and classification of the mixed working conditions are realized by the mixed programming of Labview and Matlab Software. Then, according to the characteristics of the relevant parameters of objective drivability, the advantages and disadvantages of different filtering methods for signal de-noising…

Defect Detection of Railway Fasteners Based on Improved PHOG Characteristics

SAE International Journal of Transportation Safety

China-Jiaming Hu
Northeast Electric Power University, China-Chun-Ming Wu
  • Journal Article
  • 09-08-01-0002
Published 2020-03-23 by SAE International in United States
Aiming at the problem of low recognition rate and slow speed caused by the small proportion of key area information in feature vectors of original Pyramid Histogram of Gradients (PHOG) features, an improved feature extraction method of PHOG is proposed. The PHOG feature extraction method is combined with edge feature enhancement method based on Census transform to extract feature vectors of fasteners, and dimensionality reduction is processed by Kernel Principal Component Analysis (KPCA) method to reduce the interference of redundant information. The vector is inputted into the support vector machine for training in order to get the classifier model and realize the automatic identification of the fastener’s state. The simulation results show that compared with the traditional PHOG method, this feature extraction method improves the false detection rate by 2.7%, and the complexity of the algorithm is greatly reduced.
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Theoretical Development of Localized Pseudo Damage

SAE International Journal of Passenger Cars - Mechanical Systems

Virginia Polytechnic Institute and State University, USA-Craig Altmann, John Ferris
  • Journal Article
  • 06-13-01-0003
Published 2020-02-18 by SAE International in United States
Damage is accumulated by vehicles as they travel. Current damage methods allow for the total accumulated damage to be identified; however, they do not allow for identification of the road segments that induce the largest component of the damage. The objective of this article is to develop a measure, Localized Pseudo Damage (LPD), which defines the amount of damage each individual road excitation contributes to the total accumulated pseudo damage. A novel theoretical development of LPD along with analytical and discrete simulation analyses is presented. The results show that the LPD is causal and correctly identifies the location and magnitude of damaging events. This is further demonstrated with the application of the method on a real road surface.
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