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2016-04-05
Journal Article
2016-01-0459
Jian Zhao, Jing Su, Bing Zhu, Jingwei Shan
Indirect Tire Pressure Monitoring System (TPMS) is a system which monitors the tire pressure based on the wheel speed signals from Anti-lock Brake System (ABS). In this paper, a practical indirect TPMS method is proposed to estimate the tire pressure according to the relationship between the tire pressure and the tire circumferential vibration. Firstly, the error of ABS wheel speed sensor system caused by the machining tolerance of the tooth ring are estimated based on the measured wheel speed using Recursive Least Squares algorithm. Then, the measuring error is eliminated and the vibration noise is further extracted from the from the wheel speed signal. Using the vibration noise, the resonance frequency of the tire vibration system was extracted by Maximum Entropy Spectral Estimation (MESE) based on Auto-regressive (AR) model.
2016-04-05
Journal Article
2016-01-0477
Pu Gao, Yongchang Du, Yujian Wang, Yingping Lv
The dynamic properties of disc rotor play important role in the NVH performance of a disc brake system. Disc rotor in general is a centro-symmetric structure. It has many repeated-root modes within the interested frequency range and they may have significant influence on squeal occurrence. A pair of repeated-root modes is in nature one vibration mode. However, in current complex eigenvalue analysis model and relevant analysis methods, repeated-root modes are processed separately. This may lead to contradictory result. This paper presents methods to deal with repeated-root modes in substructure modal composition (SMC) analysis to avoid the contradiction. Through curve-fitting technique the modal shape coefficients of repeated-root modes are expressed in an identical formula. This formula is used in SMC analysis to obtain an integrated SMC value to represent the total influence of two repeated-root modes.
2016-04-05
Journal Article
2016-01-0476
Yongchang Du, Yingping Lv, Yujian Wang, Pu Gao
Brake squeal is a complex dynamics instability issue for automobile industry. Closed-loop coupling model deals with brake squeal from a perspective of structural instability. Friction characteristics between pads and disc rotor play important roles. In this paper, a closed-loop coupling model which incorporates negative friction–velocity slope is presented. Different from other existing models where the interface nodes are coupled through assumed springs, they are connected directly in the presented model. Negative friction slope is taken into account. Relationship between nodes’ frictional forces, relative speeds and brake pressure under equilibrant sliding and vibrating states is analysed. Then repeated nodal coordinate elimination and substructure modal coordinate space transformation of system dynamic equation are performed. It shows that the negative friction slope leads to negative damping items in dynamic equation of system.
2016-04-05
Journal Article
2016-01-1298
Shukai Yang, Zuokui Sun, Yingjie liu, Bingwu Lu, Tao Liu, Hangsheng Hou
This work carried out a detailed analysis and optimization regarding a front disc brake squeal issue. Specifically, it explained the stability theory of complex modes for brake squeal simulation, constructed a brake system finite element model, established a simulation analysis methodology, determined the key parameters for evaluating the stability of the brake system complex modes, and carried out a model verification measurement with the SAE 2521 procedure. Finally, in order to resolve a specific 1800 Hz low frequency brake squeal issue, an optimization simulation was carried out. The obtained solutions were validated by the experimental findings.
2016-04-05
Journal Article
2016-01-1314
Ryoichi Hibino, Tomohiko Jimbo, Hiroyuki Yamaguchi, Yasuaki Tsurumi, Hideaki Otsubo, Shinji Kato
For realizing good driveability, this study aims to clarify a mechanism that vehicle longitudinal motion is generated on tip in acceleration. Experimental modal analysis or model based one is well known as a typical conventional method. However, the former requires that input force such as impulse one can be measured and generally done on a vehicle stop condition; the measurements under the driving conditions of actual vehicles are usually difficult. The latter requires that characteristic values such as stiffness and damping coefficients, which cannot be measured easily and precisely. Therefore, a new analysis method based on output experimental data is proposed. Firstly, acceleration data of some components are measured under the driving conditions with necessary and sufficient degrees of freedom such as pitch motion. It is because many parts of vehicle are vibrated interactively.
2016-04-05
Journal Article
2016-01-1316
Vincent Rovedatti, Jacob Milhorn, Richard DeJong, Gordon Ebbitt
A 1/4 scale model vehicle profile has been tested in a wind tunnel with speeds up to 300 km/h. In order to simulate the free field flow over the vehicle, the top surface of the wind tunnel is contoured. A CFD simulation of the free field flow at various speeds is used to identify the desired top streamline. Then the boundary layer growth on the top surface is calculated and the top contour is adjusted accordingly. Since this contour changes very little with flow speeds of interest, an average contour is used for a fixed top surface of the wind tunnel. Pressure drop measurements are used to verify the flow similarity to the CFD model. Wind noise measurements using surface mounted pressure transducer arrays are used to determine the acoustic loads on the vehicle surfaces.
2016-04-05
Journal Article
2016-01-1310
Yitian Zhang, David W. Herrin, T Wu, Xin Hua
The general forms of transmission loss and insertion loss are defined for multi-inlet multi-outlet mufflers using a superposition method. The superposition method is easily understandable and can be extended to any m-inlet n-outlet muffler. Transmission loss is determined assuming that the sources and terminations are anechoic whereas insertion loss considers reflections. In addition, the amplitude and phase relationship between the sources should be known a priori. This paper explains both metrics. Following this, measurement and simulation of transmission and insertion loss are demonstrated for a 2-inlet 2-outlet muffler with good agreement.
2016-04-05
Journal Article
2016-01-1315
Yongchang Du, Yingping Lv, Yujian Wang, Pu Gao
Closed-loop coupling model, based on complex eigenvalue analysis, is one of the most popular and effective methods for brake squeal analysis. In the model, coupling springs are used to represent the normal contacting force between coupled nodes. This assumption is the foundation of the model. But the physical meaning of coupling spring was seldom discussed and there’s no systematic method to determine the value of spring stiffness. This paper presents a new closed-loop coupling disc brake squeal model based on finite element component model and modal synthesis technique. Different from the traditional model, where the two nodes in a coupled node-pair are connected through a spring, in the new model they are assumed to be remain contacted tightly during vibration. Details of the model, including force analysis, coordinate reduction and transformation and complex eigenvalue decomposition are given.
2016-04-05
Journal Article
2016-01-1318
Syed F. Haider, Zissimos Mourelatos
Finite element analysis is a standard tool for deterministic or probabilistic design optimization of dynamic systems. Such an optimization requires repeated eigenvalue analyses which can be very expensive. Several reanalysis techniques have been proposed to reduce the computational cost including Parametric Reduced Order Modeling (PROM), Combined Approximations (CA), and the Modified Combined Approximations (MCA) method. However, the cost of reanalysis can be still large for models with a large number of degrees of freedom and a large number of design variables. Reanalysis methods use a basis composed of eigenvectors from both the baseline and the modified designs which are in general linearly dependent. To eliminate the linear dependency and improve accuracy, Gram Schmidt orthonormalization is employed which is costly itself. In this paper, we propose a method to reduce the orthonormalization cost and improve the efficiency of the PROM reanalysis method.
2016-04-05
Journal Article
2016-01-1303
Haiqing Xu, Chang JIN, HONG ZHOU, YI ZHOU
On the study of reducing the disturbance on driver’s attention induced by low frequency vehicle interior stationary noise, a subjective evaluation is firstly carried out by means of rank rating method which introduces Distraction Level as evaluation index. A visual-finger response test is developed to help evaluating person better recognize the Distraction Level during the evaluation. A non-linear BP neural network is then modeled for the prediction of subjective Distraction Level, in which linear sound pressure RMS amplitudes of five critical bands from 20 to 500Hz are selected as inputs of the model. Furthermore, active noise equalization (ANE) on Distraction Level is realized based on FXLMS algorithm that controls the five gain coefficients of each input of trained BP neural network model.
2016-04-05
Technical Paper
2016-01-0079
Tomohisa Harada, Yoshiyuki Hattori, Shinya Ito, Mitoshi Fujimoto, Toshikazu Hori
Recently, the electromagnetic interference to an AM radio by the noise generated from a power control unit in an HV has become a serious problem. In order to solve the problem, most of noise countermeasures focus on noise sources and noise propagation paths. On the other hand, a countermeasure in the radio receiver has been also proposed. This method detects the HV noise by using a noise sensor, and then, the noise signal is subtracted from AM radio signal which the noise superimposed. In this paper, a new noise suppression method using the digital signal processing in the AM radio receiver is proposed, which does not need noise sensors. The procedure of the method is as follows: First, a receiving AM radio signal containing HV noises is resolved into the in-phase component and quadrature component of a carrier by applying a quadrature demodulation.
2016-04-05
Technical Paper
2016-01-1552
Renato Galluzzi, Andrea Tonoli, Nicola Amati, Gabriele Curcuruto, Piero Conti, Giordano Greco, Andrea Nepote
The development of suspension systems has seen substantial improvements in the last years due to the use of variable dampers. In such solutions, the characteristic of active or semi-active devices is modified to meet desired constraints, such as comfort and road holding. Furthermore, the persisting goal of improving the efficiency of subsystems within the automotive chassis has favored the use of regenerative solutions, in which electric machines can be employed as generators to recover part of the energy otherwise dissipated as heat during cyclic excitation. Although linear electric actuators seem a straight-forward choice in vehicle vibration damping, their limited force density leads to the implementation of rotary machines together with additional transmission mechanisms to convert angular displacements into linear ones and vice versa. Regenerative suspensions present different issues that limit their efficiency, being inertial stiffening and friction the most challenging ones.
2016-04-05
Technical Paper
2016-01-0101
Carl Arft, Yin-Chen Lu, Jehangir Parvereshi
Oscillators are key components in automotive electronics systems. For example, a typical automotive camera module may have three or more oscillators, providing the clocks for microcontrollers, Ethernet controllers, and video chipsets. These oscillators have historically been built around a quartz crystal resonator connected to an analog sustaining circuit driving the crystal to vibrate at its resonant frequency. However, quartz-based devices suffer from poor performance and reliability in harsh automotive environments. SiTime has developed timing solutions based on silicon micro-electromechanical systems (MEMS) technology that exhibit better electromagnetic noise rejection and better performance under shock and vibration. In this paper, we first discuss the design and manufacturing of the MEMS-based device, with emphasis on the specific design aspects that improve reliability and resilience in harsh automotive environments.
2016-04-05
Technical Paper
2016-01-1361
Abhijit Londhe, Vivek Yadav, SenthilKumar Kannaiyan, Krishnan Karthikeyan, Ganeshan Reddy
Reducing the vibrations in the drivetrain is one of the prime necessities in today’s automobiles from NVH and strength perspectives. Also to save on material costs and to improve on fuel economy there is a need for optimizing the mass of the engine and vehicle. Platform strategy enables several variants to be designed by changing parameters like Powertrain, wheel base, payload. In those scenarios, changes in stiffness, operating speeds can impact dynamics of drivetrain and of vehicle, this leads to a greater need for addressing the NVH, durability and overall vehicle performance through simulation. Other challenges design engineers have to face are reducing vibrations transferred to vehicle through different load paths such as directly through body mounts and through axle to suspension and then to vehicle cabin. This aggravates other concerns such as shift lever vibrations, rise in in-cab noise, and generation of boom noise at certain speeds.
2016-04-05
Technical Paper
2016-01-1378
Takanori Ide, Kentaro TODA, Yasunori Futamura, Tetsuya Sakurai
Efficient method to solve large-scale eigenvalue computation in vibration is presented. NVH(Noise, Vibration and Harshness) performance is an important quality measure of the vehicle. Therefore the reduction of vibration is one of the key considerations of new automatic transmission design. In addition, accelerating product design time is another important issue. Computer Aided Engineering (CAE) is becoming a more important methodology to reduce product design time. However computational time of eigenvalue problem takes a long. We propose parallel eigenvalue computation (Sakurai-Sugiura method) for large-scale eigenvalue problems. This method has a good parallel scalability according to a hierarchical structure of the method. As a demonstrative problem, we consider large-scale eigenvalue computation of the AISIN AW FWD automatic transmission.
2016-04-05
Technical Paper
2016-01-1430
Se Jin Park, Murali Subramaniyam, Seoung Eun Kim, Tae Hyun Kim, Hee Su Sin, Dong Hag Seo, Hyu Hyeong Nam, Jeong Cheol Lee
Seating comfort is associated with the various factors and one of the principal components of a vehicle environment which can affect passenger’s comfort is vibration. The seat design plays a vital role in the vibration isolation as it is directly in contact with human body. Vibration isolation properties of a seat depend upon its dynamic parameters such as cushion, spring stiffness, and damping of seat suspension. In recent years, automotive seat designers are paying more attention for the improvement of seat cushion properties. This paper provides information about a new automotive seat concept which use double-wall 3D air mat in cushion along with foam cushion. The air-mats base fabrics are interlinked with numerous spacer threads to make a 3D structure. An optimization-based method is used to determine the optimal seat dynamic parameter for cushion (particularly for double-wall 3D air mat) based on minimizing occupant’s body discomfort.
2016-04-05
Technical Paper
2016-01-0474
Shukai Yang, Bingwu Lu, Zuokui Sun, Yingjie Liu, Hangsheng Hou
An low frequency vibration issue around 3.5 Hz surfaces during a truck program development process, and it is linked to uncomfortable driving and riding experiences. This work focuses on an analytical effort to resolve the issue by first building a full vehicle MBS model,and then carrying out a vibration response analysis. The model validation is performed using the full vehicle testing in terms of structural modes and frequency response characteristics. In order to resolve the issue which is considered to be excited mainly by the tire non-uniformity, the influence of the cab suspension, frame modes, front leaf spring system and rear balance suspension are analyzed. The root cause of the issue is found to be the rear balance suspension system, and the final optimization effort establishes the resolution measure for the issue.
2016-04-05
Technical Paper
2016-01-0475
Lingzhi Li, Jun Li, Bingwu Lu, Yingjie Liu, Zhi Zhang, Hailong Cheng, Yan Zhang, Hangsheng Hou
Excessive wind noise is one of the most complained problems by owners of new vehicles as evidenced by the 2013 JD Power IQS (Initial Quality Study). After the vehicle speed surpasses 60 mph, wind noise is gradually becoming the dominant noise source. In an effort to reduce aeroacoustic noise level, Beamforming is a very effective noise source identification technique used during vehicle wind noise development phases. Based on the delay-and-sum (DAS) planar Beamforming methodology, a large semi-circle acoustic array is designed according to the required resolution and dynamic range pertaining to actual noise source distribution on a typical passenger vehicle. Acoustic array calibration and photo overlay are accomplished by multi-point source method, and the Doppler Effect due to the wind is corrected by the location calibration method. The established system is applied to identifying the exterior noise sources on driver-side of a passenger vehicle in the wind tunnel.
2016-04-05
Technical Paper
2016-01-0479
Kuniaki Goto, Takashi Kondo, Masakiyo Takahira, Eiji Umemura, Masashi Komada, Yasuhiko Nishimura
Generally, the field pass-by noise level measurement is not stable under the influence of weather conditions , background noise and driver’s skill.So, automobile manufactures try to reproduce proving ground driving on chassis dynamometer measurement.But, the tire noise on actual road surface is difficult to replace on indoor test. In 2016,new pass-by noise regulation (UN R51-03)will take effect in Europe and Japan etc. Furthermore , 2dB stricter regulation will take effect in 2020. In addition to the acceleration run of the current regulation , UN R51-03 requests constant speed run . Therefore, the efficient measurement is necessary for vehicle development. To solve the above mentioned issues , we have developed an indoor evaluation system capable of reproducing the tire noise on road surface.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
The knocking noise is a transient structural noise triggered by the shock absorber's piston rod vibrations that excites the vibration of chassis components. Piston rod vibrations can be caused by valves motion (opening and closing) and dry friction during stroke inversions. This study investigates the shock absorber knocking noise on a twintube gas-filled automotive shock absorber and the aim is to define an acceptance criterion (threshold level) for a sample check of the component. If infact the damper derives from a large mass production, may happen that small differences in the assembly might lead to different behaviours resulting in higher or lower levels of knocking noise. To achieve the goal, experimental tests were carried out at various excitation frequencies and amplitudes. Test were performed using a oleodynamic test bench monitoring displacement and force; accelerometers were placed in proximity of the rebound valve, on the body of the damper and on the piston rod.
2016-04-05
Technical Paper
2016-01-1616
Keiichiro Iida, Kunizo Onda, Akiyoshi Iida, Chisachi Kato, Shinobu Yoshimura, Yoshinobu Yamade, Yoshimitsu Hashizume, Yang Guo
The objective of this research is to predict accurately aeroacoustical interior noise of a car for a wide range of frequency between 100 Hz and 4 kHz. In this study, one-way coupled simulation of computational fluid dynamics (CFD), structural and acoustical analyses were performed to predict flow induced interior noise. Statistical Energy Analysis (SEA), which is a traditional method for evaluating transmission of sound and interior sound field, cannot be used for a low frequency range. In this study, structural and vibrational analysis and acoustical analysis were performed to predict the interior noise. This proposed method can be used for a wide range of frequency between 100 Hz and 4 kHz including a low frequency range. In this paper, the structural and vibrational analyses were performed by using the finite element method (FEM). The acoustical analysis results were compared the wind tunnel experimental results.
2016-04-05
Technical Paper
2016-01-1617
Yoshinobu Yamade, Chisachi Kato, Shinobu Yoshimura, Akiyoshi Iida, Keiichiro Iida, Kunizo Onda, Yoshimitsu Hashizume, Yang Gou
The objective of this research is to predict accurately aeroacoustical interior noise of a car for a wide range of frequency between 100 Hz and 4 kHz. One-way coupled simulations of CFD, structural analysis and acoustical analysis were performed to predict the interior aeroacoustical noise. Statistical Energy Analysis (SEA), which is a traditional method for evaluating transmission of sound and interior sound field, cannot be used for a low frequency range, while the proposed method can be used for a wide range of frequency including a low frequency range. We predicted pressure fluctuations on the external surfaces of a car by computing unsteady flow around a car as the first step. Secondly, the predicted pressure fluctuations were fed to the subsequent structural analysis to predict vibration accelerations on the internal surfaces of the car.
2016-03-27
Technical Paper
2016-01-1725
Sitthiborn Chiawatda
The objective of a research is to investigate a suitable fuel injection strategy of a new ethanol combustion concept in compression ignition engine fueled with ethanol in compression ratio 18 for improving combustion efficiency and emission. The ethanol partially premixed combustion (EPPC) is found which to enhance the premixing combustion with low emission and high efficiency. The controlling EPPC is based on suitable lambda, strategy fuel injection and high pressure loop exhaust gas recirculation levels. The experimental investigations will be performed by varying the number of injections of each cycle, timing of the injections, the ratio between different injection pulses and the characteristic of combustion at low and full loads of engines. The results will show the combustion characteristic in terms of controllability, stability, emissions and efficiencies. Moreover, it is expected that the multi-injection strategy should be suitable for EPPC.
2016-03-27
Technical Paper
2016-01-1727
G. Magendran
Differential thrust washers are conventionally manufactured by copper base alloy grades which is often used in axle systems. The thrust washer, which is mounted between differential housing and bevel gear which has a relative motion all the time and getting thrust load during the time of differential action taking place. Thrust washer capable of absorb all the thrust loads and should not be transferred to differential housing. Bevel gear will have relative motion against the thrust washer which required higher wear resistance properties on the surface. Geometry of the thrust washer doesn’t permit to manufacture through by high carbon steel which need high capacity of forging press and very expensive. So thrust washer manufactured by low carbon steel and these properties are achieved by carburization heat treatment and followed by gas nitriding process. We have developed thrust washer to meet thrust load and wear properties with optimized the material composition.
2016-03-27
Technical Paper
2016-01-1726
Pranab Das
In-cylinder Stratification controlled HCCI combustion strategy is used in this present study to investigate combustion, cycle by cycle variation and emission behaviour of HCCI-DI combustion under various operating conditions. In this present study, 80% of the fuel was injected early during the suction stroke (Pilot injection fixed at 270 deg. bTDC) allowing sufficient time to form a lean homogeneous mixture. Rest of the fuel (20%) was injected near TDC (Main injection fixed at 20 deg. bTDC) to form a cloud of rich mixture to triggers the combustion. It was found that, at higher load when premixed equivalence ratio (caused due to early injected fuel) exceeds a threshold value, combustion phasing control becomes extremely difficult. In that situation, external EGR was supplied back to the engine to control combustion phasing of HCCI-DI combustion keeping a constant stratification level.
2016-03-27
Technical Paper
2016-01-1728
Prateek Arora, Jyotirmoy Barman, Sumit arora, Munendra Parashar
In meeting the stringent emission norms the injector selection plays a vital role. Selection of optimum injection parameters helps in achieving good spray targeting and efficient atomization of fuel to generate optimum mixing effect. The purpose of this experimental study is to investigate the effect of injection parameters on a heavy duty diesel engine performance and emission characteristics. The injection parameters such as hydraulic through flow, cone angle, number of holes & hole diameter are studied on 6-cylinder turbocharged common rail diesel engine (BS-IV). The influence of these parameters and their combinations along with the various injection strategies are analyzed using different parametric variations in order to see the combustion and performance trend of engine. The performance of the various hardware configurations are then evaluated and discussed based on the fuel consumption and exhaust emission values.
2016-03-27
Technical Paper
2016-01-1731
G. Magendran
Transmission quill gears are hot forged steel parts often used in constant mesh manual transmissions. The quill gear, which allows a drive shaft to shift its position either axially, radially, or both relative to its driving shaft. It’s having external teeth which is positively engaged with intermediate gear and sleeve which permits the required motion to drive shaft. Quill gear directly engaged with shift gears on outer surface and bearing in inner surface which needs to have high strength and durability. These properties can be improved by carburization heat treatment in existing design such processes can lead to increased costs. We have developed quill gear through powder metallurgical process and then cooled rapidly in the furnace to get high strength and wear properties with optimized the material composition and sintering conditions. Thus, we have succeeded in the development of quill gears via sinter hardening, thus eliminating the forging and second hardening process.
2016-03-27
Technical Paper
2016-01-1730
Panuwat Kangkaya
The fossil fuel which propels to vehicle is limited, the emission regulations are intensive for aware an environment. Then, a reduction of fossil fuel and promote new technology of internal combustion engine is essential. Using alternative energy as ethanol from its benefit properties likewise; oxygenated fuel for more complete combustion and reduce emissions together with direct injection spark ignition (DISI) engines are suitable. In this research, a DISI engine with wall-guided combustion system was investigated for stratified lean burn when fueled gasoline with ethanol. The condition in this experiment are controlled at constant of speed and loads which relies on general of engine operations in passenger vehicles. Performance, Fuel consumption, Emissions and Stability of combustion were measured at each surplus air-fuel ratio. The results showed that higher percentage of ethanol in gasoline obtained combustion more lean.
2016-03-27
Technical Paper
2016-01-1732
Weicheng Huang
When the vehicle parks in direct sunlight conditions, the cabin will form a high-temperature thermal environment in hot weather. Drivers would turn on the air-conditioning with relatively high gear in the most conditions to reduce the cabin temperature, which could affect the life of equipment, resulting in energy waste and increasing emissions. This study adopted solar energy in the ventilation system. When the car parks the cabin blower was driven by a solar panel mounted on the car roof to discharge heat inside the cabin real time, achieving the purpose of pre-cooling. Firstly, heat transfer model and ventilation cooling model for the cabin were established according to the theory of heat transfer, and models were modified through experiments. Besides, the impact of ventilation flow rate on the pre-cooling effect was studied based on simulation analysis.
2016-03-27
Technical Paper
2016-01-1736
Manida Tongroon, Amornpoth Suebwong, Mongkon Kananont, Siamnat Panassorn, Paritud Bhandhubanyong
The effects of high quality biodiesel, namely, partially Hydrogenated Fatty Acid Methyl Ester or H-FAME, on 50,000km on-road durability test of unmodified common-rail vehicle have been investigated.z Thailand brand new common-rail light duty vehicle, Isuzu D-Max Extended cab, equipped with 4JK1-TCX engine (DOHC 4-cylinder 2.5L, M/T 4x2, Euro IV emission) was chosen to undergo on-road test composed of well-mixed types of mountain, suburb and urban road conditions over the entire 50,000km. Palm-derived high quality biodiesel, H-FAME, conforming to WWFC (worldwide fuel charter) specification, was blended with normal diesel (Euro IV) at 20% (v/v) as tested fuel. Engine performance (torque and power), emission (CO, NOx, HC+NOx and PM), fuel consumption and dynamic response (0-100km acceleration time and maximum velocity) were analyzed at initial, middle and final distance; whereas, used lube oil analysis was conducted every 10,000km.
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