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Viewing 91 to 120 of 23978
2016-04-05
Technical Paper
2016-01-0099
Deepak Venkatesh, Arockia Selvakumar
The concept of camless engines enables us to optimize the overall engine efficiency and performance, as it provides great flexibility in valve timing and valve displacement. This paper deals with design of camless engines with pneumatic actuator. The main objective of this research is to build a prototype and test its performance at different engine speeds. Also an extensive research on the sensors is done to detect the various sensors that could be used to identify the crankshaft position. In addition the overview of the proposed camless engine system is focused with the design principles and the components used. The developed pneumatic system is capable of actuating at 1500 rpm and demonstrates the ability of pneumatic actuators to be used in an internal combustion engine with low rpm needs.
2016-04-05
Technical Paper
2016-01-1302
Junji Yoshida, Koki Tanaka
Operational transfer path analysis (TPA) is one of TPA methods recently developed. This method calculates contributions of reference points, those are typically set close to force input points, to vehicle interior noise by using only operational data. Through operational TPA (OTPA), effective vibration and noise reduction at the vehicle interior could be achieved by carrying out an intensive countermeasure to the high contributing part. However, performing effective countermeasure becomes difficult in case some reference points have similar high contributions by the influence of a large vibration mode. In such a case, obtaining high contributing vibration mode and considering how to reduce the mode is better than trying to find out a highest contributing reference point. In the OTPA, not only the reference point contribution but also additional useful information such as principal component could be calculated.
2016-04-05
Journal Article
2016-01-0957
Patrick Schrangl, Roman Schmied, Stephan Stadlbauer, Harald Waschl, Luigi del Re, Bernhard Ramsebner, Christoph Reiter
Abatement and control of emissions from passenger car combustion engines have been in the focus for a long time. Nevertheless, advancements in emission legislation and engine control both enable and require further improvements and application of new techniques. To address upcoming real world emission targets, knowledge of current engine emissions is crucial. Still, adequate sensors for transient emissions are seldom available in production engines. One way to address this issue is applying virtual sensors which utilize already available sensor information in an ECU to provide estimates of not measured emissions. For real world application it is important that the virtual sensor works in varying environmental and operating conditions and here the choice of input variables can have a strong impact. In this work a method to set up virtual sensors by means of DOE and iterative identification of polynomial models is extended to address varying conditions.
2016-04-05
Journal Article
2016-01-1583
Brian R. McAuliffe, Alanna Wall, Guy Larose
During the past year, a novel turbulence generation system has been commissioned in the National Research Council (NRC) 9 m Wind Tunnel. This system, called the Road Turbulence System was developed to simulate with high fidelity the turbulence experienced by a heavy duty vehicle on the road at a geometrical scale of 30%. The turbulence characteristics that it can simulate were defined based on an extensive field measurement campaign on Canadian roads for various conditions (heavy and light traffic, topography, exposure) at heights above ground relevant not only for heavy duty vehicles but also for light duty vehicles. In an effort to improve continually the simulation of the road conditions for aerodynamic studies on a light duty vehicle, a study was carried out at NRC to define the applicability of the Road Turbulence System to aerodynamic testing of full-scale light duty vehicles.
2016-04-05
Journal Article
2016-01-1597
Christopher Collin, Steffen Mack, Thomas Indinger, Joerg Mueller
The open jet wind tunnel is a widespread test section configuration to develop full scale passenger cars in automotive industry. However, using a realizable nozzle cross section for cost effective aerodynamic development is always connected to certain wind tunnel effects. Wind tunnel wall interferences, which are not present under real road conditions, can affect the measurement of aerodynamic forces in a wind tunnel and cause the requirement to apply wind tunnel corrections. This work contains the results of a CFD approach, using unsteady DDES to determine the in terms of drag force optimal longitudinal position of a full scale car inside the open jet wind tunnel test section, at which interference effects between nozzle, open jet and car compensate each other. Hence, the optimal position for the selected car is proposed for – depending on the method used for dynamic pressure determination – plenum or nozzle method.
2016-04-05
Journal Article
2016-01-1595
Haibo Wu, Jiangbin Zhou, Qian Chen, Gongwen Liu, Chaoqun Qian
In this paper we present the work which was done at Shanghai-VW for using computational aero-acoustic (CAA) simulation in the vehicle development process to assess and improve the buffeting behavior of a vehicle when the rear side window is open. In the first step, a methodology was established and validated against wind tunnel tests using a Sedan. The methodology consists of a calibration of the CAA model to represent the properties of the cabin interior of the real car in terms of damping, wall compliance and leakage followed by CAA simulations of the full vehicle at different wind speeds to obtain the transient flow field around the exterior shape and inside the passenger compartment. The interior noise spectra are directly calculated from the transient pressure inside the cabin.
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
2016-01-1310
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
2016-01-1374
Julian Wiederer, Lukas Leitner, Christian Endisch, Hans Reiss
Modern combustion engines use a multitude of sensors and actors to achieve low emissions and high fuel efficiency. During series production a major challenge is to ensure the correct operation of every engine part. A common method is to test engines in end-of-line (EOL) cold test stations, where the engines are not fired but tugged by an electric motor. Tests are performed up to 100 % production volume. In this work we present a physically based 0D model for dynamic simulation of combustion engines under EOL test conditions. Our goals are the analysis of manufacturing faults regarding their detectability, the enhancement of test procedures, the simulation of varying environmental conditions, and the early validation of testability for new engine generations. Physical experiments are prohibitive in production environments, and the simulative approach reduces them to a minimum.
2016-04-05
Journal Article
2016-01-1614
Edward Duell, Amir Kharazi, Paul Nagle, Per Elofsson, David Söderblom, Christer Michael Ramden
Scania’s has opened a new climatic wind tunnel test facility, located at the Scania Technical Center in Södertälje, Sweden. This facility is designed for product development testing of heavy trucks and buses in a range of controllable environments. Having this unique test environment at the main development center enables Scania to test its vehicles in a controlled repeatable environment all year, improving lead times from design to production, producing higher quality and more reliable vehicles, and significantly improves capability for large vehicle performance research. This state-of-the-art facility provides environmental conditions from -35℃ to 50℃ with humidity control from 5 to 95 percent. The 13m2 nozzle wind tunnel can produce wind speeds up to 100 km/h. In addition to the ‘standard features’ listed above for a climatic wind tunnel, this facility includes several additional capabilities.
2016-04-05
Journal Article
2016-01-1624
Brian R. McAuliffe, Annick D'Auteuil
Turbulence is known to influence the aerodynamic and aero-acoustic performance of ground vehicles. What is not thoroughly understood are the characteristics of turbulence that influence this performance and how they can be applied in a consistent manner for aerodynamic design and evaluation purposes. Through collaboration between Transport Canada and the National Research Council Canada (NRC), a project was undertaken to develop a system for generating road-representative turbulence in the NRC 9m Wind Tunnel, named the Road Turbulence System (RTS). This endeavour was undertaken in support of a larger project to evaluate new and emerging drag reduction technologies for heavy-duty vehicles. A multi-stage design process was used to develop the RTS for use with a 30% scale model of a heavy-duty vehicle in the NRC 9m Wind Tunnel.
2016-04-05
Technical Paper
2016-01-0270
Zhigang Wei, Limin Luo, Michael Start, Litang Gao
Statistical parameters, such as mean, standard deviation, in particular, failure probability are of significant interest to durability and reliability engineers. These parameters can be estimated from samples, however, these estimated parameters usually contain significant uncertainties and cannot be fully representative of the population, particularly, for test data with small sample sizes. Generally, sample size is a balanced result between durability/reliability performance and cost. There are several ways to characterize and quantify the uncertainty caused by the sample size effects, and one of the most commonly used engineering approach for failure probability is RxxCyy, in which xx and yy represent xx% reliability (R) and yy% confidence (C). RxxCyy criterion is commonly used in both test-to-failure method and the binomial test method [4-8].
2016-04-05
Technical Paper
2016-01-0128
Philip Koopman, Michael Wagner
Software testing is too often simply a hunt for bugs, rather than a well considered exercise in ensuring quality. A more methodical approach than simply drive-patch-drive-patch will be required to deploy safe autonomous vehicles at scale. The development V process sets up a framework that ties each type of testing to a corresponding design or requirement document, but is insufficient to deal with the sorts of novel testing problems that face autonomous vehicles. Based on our experience with several years of stress-testing autonomous vehicles, we propose an autonomous vehicle testing approach that can be thought of as an extension to ISO 26262 practices and the traditional V processes. Our testing strategy matches well defined design, requirement, and environmental fault models with matching layers of phased testing and deployment. A multi-layered testing plan can manage exposure to help boot-strap fleet deployment in a methodical way.
2016-04-05
Technical Paper
2016-01-1495
Motomi Iyoda, Tom Trisdale, Rini Sherony, Daniel Mikat, William Rose
EDR (Event Data Recorder) is a function of recording vehicle status at the timing of accident. Toyota introduced EDR from August 2000 one after the other. Now about 70% of Toyota vehicles in North America have EDR. This is more than about 50% EDR coverage of all vehicles in North America. There is EDR regulation in USA, so we record EDR data based on the regulation. We think this is the minimum requirement and we record additional necessary data required from accident reconstruction. They are, (1) additional pre-crash data, (2) additional side crash recording system, (3) roll over recording system, (4) pedestrian protection PUH (Pop Up Hood) recording system, (5) non-crash triggered recording system VCH (Vehicle Control History), etc. Commercially available tool is necessary for EDR data retrieval, based on the regulation in USA. So we adopted BOSCH CDR (Crash Data Retrieval). All Toyota EDR can be retrieved using CDR for all over the world including North America.
2016-04-05
Technical Paper
2016-01-1577
Tateru Fukagawa, Shinnosuke Shimokawa, Eiji Itakura, Hiroyuki Nakatani, Kenichi Kitahama
The aerodynamic stability of a vehicle with lighter weight and lower drag for saving energy is reduced in cross wind disturbance. In particular, body shapes with low drag have unsteady motion caused by their aerodynamic yaw moment in this situataion. In order to verify fluctuation of unsteady aerodynamic forces of an actual vehicle, a direct measurement method of the transient aerodynamic force on crosswind test using the data of the force of Inertia and the loads of tires is established . The former data is measured with a inertia sensor comprised of a gyro, an acceleration sensor, GPS sensor, and the latter is measured with a wheel force sensor. The noise of the measurement data caused by the inherent frequency of tires is reduced by using the spectral subtraction method. As a result , aerodynamic data measured on cross wind test corresponded to the wind tunnel test data. Numerical expression is defined in order to model the transient aerodynamic forces in cross wind.
2016-04-05
Technical Paper
2016-01-0050
Huafeng Yu, Chung-Wei Lin, BaekGyu Kim
Modern vehicles can have millions of lines of software, for vehicle control, infotainment, etc. The quality and correctness of the software play a key role in the safety of whole vehicle. In order to assure the safety, engineers give an effort to prove correctness of individual subsystems or their integration using testing or verification methods. One needs to eventually certify that the developed vehicle as a whole is indeed safe using the artifacts and evidences produced throughout the development cycle. Such a certification process helps to increase the safety confidence of the developed software and reduce OEM’s liability. However, software certification in automotive domain is not yet well established, compared to other safety-critical domains, such as medical devices and avionics. At the same time, safety-relevant standards and techniques, including ISO 26262 and assurance case, have been well adopted.
2016-04-05
Technical Paper
2016-01-0102
Michael Ludwig, Martin Rieder, Marco Wolf
The intent to reduce CO2-emssions and the necessity to assess the emission levels of car engines have resulted in implementation of the new European drive cycle (NEDC). To underrun targeted threshold values in the NEDC, an electrification of cars is inevitable. Different concepts, e.g. mild- and micro-hybrid, as well as plug-in hybrid approaches, are capable to achieve the target of 90g/km. What all these technologies have in common is that they are based on an electric engine which has to be commutated. Design examples comprise Belt-Driven Starter Generators, Integrated Starter Generators, or stand-alone electric motors. Rotor-position sensors (RPS) are used within these machines to gain the angle information of the rotor, and therefore this angle-information is directly linked to robustness and performance of the electric powertrain. The intent of this paper is the generation of an overview of different sensor technologies suitable for rotor-position measurement.
2016-04-05
Technical Paper
2016-01-1028
Qinqing Chen, Jimin Ni, Xiuyong Shi, Qiwei WANG, Qi Chen, Si Liu
In this paper, the matching of turbocharger and engine was studied base on a domestic 1.5 L gasoline engine, and the numerical simulation of the waste-gate valve opening diameter was calculated. The main research contents and results are summarized as follows: (1)Different exhaust bypass valve actuators were compared and analyzed, the results show that the electric motor actuator can be better matched in all conditions of engine, so the electric motor actuator have more development prospects than the solenoid pneumatic actuator which is the mainstream now. (2)A 1.5 L turbocharged gasoline engine simulation model was established by GT-Power, and the performance of external characteristic combined with the actual test data values were calibrated.
2016-04-05
Technical Paper
2016-01-0049
Jinwei Zhou, Roman Schmied, Alexander Sandalek, Helmut Kokal, Luigi del Re
The implementation of Advanced Driver Assistant Systems (ADAS) in production standard vehicles requires extensive test bench and field testing as the manufacturer has to guarantee for functionality and safety in all possible traffic environment situations. Especially field tests consume a lot of time and money which is the reason why methods that allow a reduction of field test hours obtain high attention. Virtual ADAS testing using a simulation environment provides great potential in reducing real world testing and therefore currently much effort is spent on the development of such tools. This work proposes a simulation and hardware-in-the-loop (HIL) framework, which helps to create a virtual test environment for ADAS based on real world test drives. The idea is to reproduce environmental conditions obtained on a test drive within a simulation environment.
2016-04-05
Technical Paper
2016-01-0412
Mathialgan Balaji, B Jaiganesh, Selvakumar Palani, K Somasundaram, Srinivasa Rao
Tractors are self-propelled vehicle finds its major application and in agriculture, haulage and Costruction equipment applications. Product development life cycle of developing a tractor is more as against the automobiles, since tractors as to undergo rigorous field testing. Bringing more realistic component/system level test in the test lab will drastically reduce the product development cycle time. Non availability of standard usage pattern and customer correlated proving ground possess a greatest challenge for bringing field to lab. As a result, every time tractor has to be instrumented with sensors and load-timehistory needs to be acquired in various field as per usage pattern. Raw data from field cannot be used directly for lab testing, since the number of cycles will be very high. This data as to be edited based on damage editing/fatigue sensitivity analysis technique.
2016-04-05
Technical Paper
2016-01-0417
With the advent of the energy crisis, lightweight of automobile has become a trend. Aluminum Alloy (AA) is used in automobile industry increasingly and the study of the AA plate formability becomes more important. This paper proposed new methods for strain hardening and edge stretching limit based on the digital image correlation (DIC) technique. Using this 3D dynamic strain measurement system, real-time whole field bi-directional strain of large AA sheets during stretching can be observed, especially the maximum plastic strain before breakage. The true strain data of every point of the sheets can be obtained. Based on these large pre-tension sheets, a lot of notch-shape coupons with three different pre-strain conditions(5%,10% and fractured) can be cut from them. Compared to the traditional average value, this pre-strain is more accurate and effective. Then a dual-camera 3D-DIC system is utilized to measure edge stretching limit of these notch-shape coupons.
2016-04-05
Technical Paper
2016-01-0429
Paul Augustine, Timothy Hunter, Nathan Sievers, Xiaoru Guo
The performance of a structural design depends upon the assumptions made on input load. In order to estimate the input load, during the design stage of the suspension assembly of a BAJA car, designers invest immense amount of time and effort to formulate the mathematical model of the design. The theoretical formulations may include idealization errors which can affect the performance of the car as a final product. These errors in estimating design load will lead to more weight or less strength than needed. This discrepancy between the assumed input load and the actual load from the environment can be eliminated by performing a real life testing process using load recovery methodology. Commercial load cells exist in industry to understand the real world loading of structures. A limitation of load cells is that the structure needs to be modified to accept the load cell and not all desired loading can be measured.
2016-04-05
Journal Article
2016-01-0444
Kemal Çalışkan, Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
This paper presents a performance analysis study for the Rule-optimized Fuzzy-Logic controller of a Semi-active Suspension system. The Rule-optimized controller uses a Fuzzy Logic scheme which offers new opportunities in the improvement of vehicle ride performance. An eleven degree of freedom full vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. An optimization process to obtain the optimum Fuzzy Logic membership functions and the optimum rule-base of the semi-active suspension controller is proposed. Discrete optimization has been performed with a Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle.
2016-04-05
Technical Paper
2016-01-0446
Chen Liang, Guolin Wang, Zhou Zheng
A three-dimensional finite element model of radial tire 205/55R16,established by ABAQUS software,is used to simulate tire force and moment properties. Drum tests are designed to validate the simulation model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented, based on string balance contour theory, which simplifies the belts pressure share ratio as trapezium. And a program for calculating tire’s contour is compiled. Different tire contours are designed according to different belt pressure share ratios. One of the contours is selected according to the positive affect to cornering stiffness. Compare the selected newly designed tire with the original one, it is found that the newly designed tire’s contact area, longitudinal stiffness,lateral stiffness,camber stiffness and cornering stiffness increase while its radial stiffness decreases.
2016-04-05
Technical Paper
2016-01-0448
Yuliang Yang, Yu Yang, Ying Sun, Zhihong Dong, Yunquan Zhang
To improve the vehicle NVH performance, reduce the vibration of the exhaust system, average driving DOF displacement (ADDOFD) and dynamic analysis are used to optimize hanger locations. Based on the finite element analysis and rigid-flexible coupling analysis, exhaust system analysis model was established. According to the finite element model of the exhaust system, the free-free modal analysis is carried out, and the position of the hanging point of the exhaust system is optimized by using the ADDOFD method. Furthermore, through the dynamics analysis, the force of each hanger to the body is calculated by the dynamic analysis, then verify the rationality of the hanging position. The combination of the two methods can effectively determine the better NVH performance of the exhaust system with hanger locations in the earlier vehicle development process.
2016-04-05
Technical Paper
2016-01-0449
Xian Xu, Wei Chen, Yuan Cao, Yingxiong Zhang, Hu Guo
The stiffness of the frame has a great influence on the ride comfort of the heavy truck. Reducing frame thickness was proved to be unacceptable in terms of ride comfort, which is verified by the testing results. The truck frame was reinforced in order to improve the ride comfort. The modal analyse showed that the pitch frequency of the vehicle has increased 0.5 Hz and the frequency response has decreased by 20%. A detailed model including a flex frame, chassis suspension, cab suspension, driveline, etc., was built by MSC.ADAMS to research the influence of frame stiffness on the heavy truck ride comfort. The Simulation results showed that the ride comfort can be improved by reinforce the frame, and the ride comfort can be improved by 5%~10%. The results of this study need to be further examined through filed testing.
2016-04-05
Technical Paper
2016-01-0464
Lingyang Li, Wei Wu, Ji Chen, Jianpeng Shi, Xicheng Wang, Liuhua Qian
In order to expand the product design and development capabilities of Electric Power Steering (EPS) system, a passenger car's simulation model integrated with EPS system model will be made, and do some analytical investigation in this paper. Through simplifying the architecture model of EPS system, the mathematical equation expressions of steering wheel and column, worm gear reducer, rack and pinion, steer-wheels, brushed DC electrical motor, and ECU assistance and compensation laws will be described. A number of tests on the EPS full system and subsystems and components will be executed. The tests' results will be used as the input parameters of the model, and then be used for model validations. After that, the EPS system model will be created. Since the most important part of control logic strategy is the top secret of steering assembly supplier and it could't be provided to OEM in details or not even a black-box model directly.
2016-04-05
Journal Article
2016-01-0468
Jiageng Ruan, Paul Walker, Nong Zhang, Guangzhong Xu
Regenerative braking has been widely accepted as a feasible option to extend the mileage of electric vehicles (EVs) by recapturing the vehicle’s kinetic energy instead of dissipating it as heat during braking. The regenerative brake force provided by a generator is applied on the wheels in an entirely different manner compared to the traditional hydraulic-friction brake system. Drag torque and efficiency loss may be generated by transmitting the braking force from motor, axles, differential and, specifically in this paper, a two-speed dual clutch transmission (DCT) to wheels. Additionally, motors in most battery EVs (BEVs) and hybrid electric vehicle (HEVs) are only connected to front or rear axle. Consequently, conventional hydraulic brake system is still necessary, but dynamic and supplement to motor brake, to meet particular brake requirement and keep vehicle stable and steerable during braking.
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
2016-01-0479
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.
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