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Bearing Fault Diagnosis of the gearbox using blind source separation

Nanjing University of Science & Technology-Hong Zhong, Jingxing Liu, Liangmo Wang, Yang Ding, Yahui Qian
  • Technical Paper
  • 2020-01-0436
To be published on 2020-04-14 by SAE International in United States
Gearbox fault diagnosis is one of the core research areas in the field of rotating machinery condition monitoring. The signal processing-based bearing fault diagnosis in the gearbox is considered as challenging as the vibration signals collected from acceleration transducers are, in general, a mixture of signals originating from an unknown number of sources, i.e. an underdetermined blind source separation (UBSS) problem. In this study, an effective UBSS-based algorithm solution, that combines empirical mode decomposition (EMD) and kernel independent component analysis (KICA) method, is proposed to address the technical challenge. Firstly, the nonlinear mixture signals are decomposed into a set of intrinsic mode function components (IMFs) by the EMD method, which can be combined with the original observed signals to reconstruct new observed signals. Thus, the original problem can be effectively transformed into an over-determined BSS problem. Then, the whitening process is carried out to convert the over-determined BSS into determined BSS, which can be solved by the KICA method. Finally, the ant lion optimization (ALO) is adopted to further enhance the performance of the EMD-KICA…
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A Holistic Approach to Develop a Modern High Power Density Diesel Engine to Meet Best-in-class NVH levels.

Mahindra & Mahindra, Ltd.-Vikraman Vellandi, Prasad Namani, Rajkumar Bhagate, Madhu Chalumuru
  • Technical Paper
  • 2020-01-0406
To be published on 2020-04-14 by SAE International in United States
The ever-increasing customer expectations put a lot of pressure on car manufacturers to constantly reduce the noise, vibration and harshness (NVH) levels. This papers presents the holistic approach used to achieve best-in-class NVH levels in a modern high-power density 1.5 lit 4 cylinder diesel engine. The base engine architecture was designed with NVH reduction features such as crank-offset, cast iron crankcase, stiffened ladder frame, structural oil pan and front cover. Piston skirt profile was optimized to reduce the slapping noise by carefully studying the secondary motion and skirt contact pressure. The plastic parts such as cylinder head cover and intake manifold were designed with closely spaced ribs and high wall thickness. Natural frequency targets for different parts were set for the entire engine at component level and system level and confirmed through simulations. High frequency acoustic simulation was carried out to identify and improve the areas of high surface velocity. "Acoustic holography" technology was extensively used to identify the areas of high noise radiation in the running engine. Based on the measurements, it was identified…
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Random Vibration Fatigue Life Assessment of Transmission Control Module (TCM) Bracket Considering the Mean Stress Effect

General Motors LLC-Neeraj Carpenter, Sudeep Yesudas, Michael D. Nienhuis
  • Technical Paper
  • 2020-01-0194
To be published on 2020-04-14 by SAE International in United States
Random loads are experienced by many engineering systems/components such as the housing and the brackets mounted on the chassis of an automobile, wind blowing on the wind turbine blades, Printed Circuit Board (PCB) used in battery electric vehicles, fuel cell stacks mounted on housing of a fuel cell etc. In automotive systems, random load is caused due to unevenness of the road surface. As these loads are varying in nature, it could lead to the fatigue failure of systems experiencing such loads. To ensure structural integrity, they are designed considering random loads and commercially used FE software packages have the capabilities available to evaluate random vibration fatigue. While above mentioned systems undergo random loads during operation, there are other loads/stresses also acting on them such as assembly loads (bolt preload), residual stresses due to casting, static loads i.e. load due to belt or chain drive etc. Consideration of all significant loads are extremely important for a design engineer and CAE analyst while designing such systems in order to ensure the reliability of their design. The…
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Heartbeat Detection Technology for Monitoring Driver's Physical Condition

Aisin Seiki Co., Ltd.-Kento Tsuchiya, Kenta Mochizuki
Keio University-Tomoaki Ohtsuki, Kohei Yamamoto
  • Technical Paper
  • 2020-01-1212
To be published on 2020-04-14 by SAE International in United States
In recent years, the number of reported traffic accidents due to sudden deterioration in driver’s physical condition has been increasing, and it is expected to develop a system that prevents accidents even if physical condition suddenly changes while driving, or reduces damage through vehicle body control.For this purpose it is necessary to detect sudden changes of the driver’s physical condition, and research is being conducted widely. Among them, it is reported that some of such changes may appear in the heartbeat interval. In other words, by acquiring the driver's heartbeat interval in real time, it may be possible to detect the sudden changes, and reduce traffic accident. Even if a traffic accident has occurred, the damage can be reduced by emergency evacuation immediately after detecting sudden changes. Therefore, we focused on the technology to detect the heartbeat interval wiht 24GHz microwave doppler radar, which can acquire heartbeat non-contactly while maintaining the interior design and passenger’s privacy. Doppler radar with microwave is sensitive enough to detect heartbeat, but vibration noise is also superimposed on the sensor…
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Active and Passive Control of Torsional Vibration in Vehicle Hybrid Powertrain System

Tongji University-Lijun Zhang, Shijuan Zhang, Dejian Meng, Jie Xu
  • Technical Paper
  • 2020-01-0408
To be published on 2020-04-14 by SAE International in United States
The vibration characteristics of hybrid vehicles are very different from that of traditional fuel vehicles. In this paper, the active and passive control schemes are used to inhibit the vibration issues in vehicle hybrid powertrain system. Firstly the torsional vibration mechanical model including engine, motor and planetary gear subsystems is established. Then the transient vibration responses of typical working condition are analyzed through power control strategy. Consequently the active and passive control of torsional vibration in hybrid powertrain system are proposed. The active control of the motor and generator torque are designed and the vehicle longitudinal vibration is reduced. The vibration of the planetary gear system is ameliorated with passive control method by adding torsional vibration absorbers to power units. The vibration characteristics in vehicle hybrid powertrain system are effectively improved through the active and passive control.
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A Research on Multi-disciplinary Optimization of the Vehicle Hood at Early Design Phase

Changan Automobile Co., Ltd.-Ruyi Chen
Chongqing University-Huijie Xu, Yue Fu, Guan Lin, Zhenfei Zhan
  • Technical Paper
  • 2020-01-0625
To be published on 2020-04-14 by SAE International in United States
Vehicle hood design is a typical multi-disciplinary task. It has to meet the demands of different attributes like safety, dynamics, statics, NVH (Noise, Vibration, Harshness). Multi-disciplinary optimization (MDO) of vehicle hood at conceptual design phase is an efficient way to support right design decision and avoid late-phase design changes. However, due to lacking of CAD models, it is difficult to realize MDO at conceptual design phase. In this research, a new method of design and optimization at conceptual design phase is proposed to improve the design efficiency. Firstly, a parametric concept hood model is first built to optimize the structure size, shape and topography. Secondly, an integration automatic platform is developed to integrate CAD/CAE software to call simulation queen, undertake sensitivity analysis and find optimum result. Besides, a multi-disciplinary design example of vehicle hood is given as a test of the proposed methodology in details. The results show that this method reduce weight by 10.1%, improve pedestrian protection performance score from 7.35 to 7.65 according to the China New Car Assessment Program(C-NCAP).
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N&V Component Structural Integration and Mounted Component Durability Implications

General Motors LLC-Mark Stebbins, Joseph Schudt
  • Technical Paper
  • 2020-01-1396
To be published on 2020-04-14 by SAE International in United States
Exterior component integration has presented competing integration challenges for suitable exterior styling, safety, N&V structural feel and component durability balanced performances. Industry standard practice of N&V vehicle mode mapping uses vehicle source, path and receiver considerations for component mode frequency placement. Mounted component mode frequency performance can have an influence on structural feel and durability performances. Component integration headwinds have increased with additional nonstructural component styling content, component size, component mass and added sensor modules. Based on first principles, the effective mass of exterior mounted components are increased due to the geometric overhang from structure. Component input vibration levels are compounded due to the cantilevered nature as well as relative positioning to the suspension and propulsion vehicle source inputs locations. Examples of vehicle end mounted components include but are not limited to headlamps, side mirrors, end gates, bumpers and fascia. Our goal is to establish basic expectations for the behavior of these systems, and ultimately to consolidate our existing rational and approaches that can be applied to such integrated systems. The focus of this paper…
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New Integrated Electromagnetic and NVH Analyses of Induction Traction Motors for Hybrid and Electric Vehicle Applications

General Motors LLC-Song He, Jingchuan Li, Michael Muir, Gautam GSJ, Bhyri Rajeswara Rao
  • Technical Paper
  • 2020-01-0413
To be published on 2020-04-14 by SAE International in United States
Electric motor whine is one of the main noise sources of hybrid and electric vehicles. Compared with permanent magnetic motors, characterization and prediction of traction induction motor is particularly challenging due to high computational costs to calculate the electro-magnetic (EM) forces as noise source, as well as motor slip and harmonic orders change at different torque/speed operating conditions. Historically, induction motor NVH is designed qualitatively by optimizing motor topology including rotor bar, pole number and slot counts etc. A new integrated electromagnetic and NVH analysis method is developed and successfully validated at all dominant motor orders for an automotive traction motor, which enables quantitative prediction of induction motor N&V performance in early design stage: First, a new Equivalent Rotor Current Method (ERCM) is proposed that significantly reduces the computational time required to calculate the EM force over transient response. Dominant force orders are compared with conventional EM finite-element (FE) results and the new ERCM method shows good correlation. Next, a High-Fidelity (Hi-Fi) mechanical FE model is developed for the induction motor stator, with less than…
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Test Bench for Static Transmission Error Evaluation in Gears

Politecnico di Torino-Carlo Rosso
Politecnico di Torino / GeDy TrAss-Tommaso Maggi, Claudio Marcellini, Fabio Bruzzone
  • Technical Paper
  • 2020-01-1324
To be published on 2020-04-14 by SAE International in United States
In this paper a test bench for measuring the Static Transmission Error of two mating gears is presented and a comparison with the results obtained with the code GeDy TrAss and a commercial Finite Element software are shown. Static Transmission Error is considered as the main source of overloads and Noise, Vibration and Harshness issues in mechanical transmissions. It is defined as the difference between the theoretical angular position of a gear under load in quasi-static conditions and the real one. This parameter strictly depends on the applied torque and the tooth macro and micro-geometry. The test bench illustrated in this work is designed to evaluate the actual Static Transmission Error of two gears under load in quasi-static conditions. In particular this testbed can be divided in two macro elements: the first one is the mechanism composed by weights and pulleys that generates a driving and a breaking torque up to 500 Nm. The second element is composed by two structures called “support”: one fixed to the floor and the other movable in order to…
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Accelerometer-Based Estimation of Combustion Features for Engine Feedback Control

Army Research Laboratory-Kenneth Kim
Dept of Army-Chol-Bum Kweon
  • Technical Paper
  • 2020-01-1147
To be published on 2020-04-14 by SAE International in United States
An experimental investigation of non-intrusive combustion sensing was performed using a tri-axial accelerometer mounted to a small-bore high-speed 4-cylinder diesel engine. This study investigates potential techniques to extract combustion features from accelerometer signals to be used for cycle-to-cycle engine control. Selection of accelerometer location and vibration axis were performed by analyzing vibration signals for three different locations along the block for all three of the accelerometer axes. A magnitude squared coherence (MSC) statistical analysis was used to select the best location and axis. Based on previous work from the literature, the vibration signal filtering was optimized and the filtered vibration signals were analyzed. It was found that the vibration signals correlate well with the second derivative of pressure during the initial stages of combustion. Two combustion parameters were the focus of this investigation, start of combustion (SOC) and crank angle of fifty-percent heat release (CA50). The results showed that, for a wide range of engine conditions, SOC can be obtained solely from the first derivative of the vibration signal with respect to crank angle. In…