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Viewing 1 to 30 of 8155
2010-04-12
Technical Paper
2010-01-0372
Baoyu Wu, Guo Xuexun, Jun Yan, Qi Sun
Speed ratio and clamping force are two of the metal-belt CVT control targets. Conventional control strategies can not correspond to the driver's intention or provide various driving environment. A fuzzy logic ratio control algorithm and a fuzzy logic clamping force control algorithm for a metal-belt CVT are proposed. Nevertheless, high-quality fuzzy control rule base and factors of FLC are difficult to gain because repeated tests and experts' experience are needed. Therefore, genetic algorithm (GA) is introduced to optimize the fuzzy control algorithms. Using the optimized fuzzy control algorithms, Metal-belt CVT control simulations were implemented. The results show that a faster response and better robustness can be gained when compared with those of the PID control.
2011-04-12
Journal Article
2011-01-0344
Gilsu Choi, Zhuxian Xu, Ming Li, Shiv Gupta, Thomas Jahns, Fred Wang, Neil A. Duffie, Laura Marlino
This paper introduces a promising approach for developing an integrated traction motor drive based on the Integrated Modular Motor Drive (IMMD) concept. The IMMD concept strives to meet aggressive power density and performance targets by modularizing both the machine and power electronics and then integrating them into a single combined machine-plus-drive structure. Physical integration of the power electronics inside the machine makes it highly desirable to increase the power electronics operating temperature including higher power semiconductor junction temperatures and improved device packaging. Recent progress towards implementing the IMMD concept in an integrated traction motor drive is summarized in this paper. Several candidate permanent magnet (PM) machine configurations with different numbers of phases between 3 and 6 are analyzed to compare their performance characteristics and key application features.
2011-04-12
Journal Article
2011-01-0268
Jeffery R. Anderson, E. Harry Law
Traditional Electronic Stability Control (ESC) for automobiles is usually accomplished through the use of estimated vehicle dynamics from simplified models that rely on parameters such as cornering stiffness that can change with the vehicle state and time. This paper proposes a different method for electronic stability control of oversteer by predicting the degree of instability in a vehicle. The algorithm is solely based on measurable response characteristics including lateral acceleration, yaw rate, speed, and driver steering input. These signals are appropriately conditioned and evaluated with fuzzy logic to determine the degree of instability present. When the “degree of instability” passes a certain threshold, the appropriate control action is applied to the vehicle in the form of differential yaw braking. Using only the measured response of the vehicle alleviates the problem of degraded performance when vehicle parameters change.
2011-04-12
Journal Article
2011-01-0437
Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies.
2011-04-12
Journal Article
2011-01-0431
Mina M.S. Kaldas, Kemal Çalışkan, Roman Henze, Ferit Küçükay
Following the developments in controlled suspension system components, the studies on the vertical dynamics analysis of vehicles increased their popularity in recent years. The objective of this study is to develop a semi-active suspension system controller using Adaptive-Fuzzy Logic control theories together with Kalman Filter for state estimation. A quarter vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A Kalman Filter algorithm is constructed for bounce velocity estimation, and its accuracy is verified through measurements performed with external displacement sensors. The benefit of using adaptive control with Fuzzy-Logic to maintain the optimal performance over a wide range of road inputs is enhanced by the accuracy of Kalman Filter in estimating the controller inputs. A gradient-based optimization algorithm is applied for improving the Fuzzy-Logic controller parameters.
2011-04-12
Technical Paper
2011-01-0447
Arkadeb Ghosal, Paolo Giusto, Prakash Peranandam, Purnendu Sinha, Haibo Zeng
Recent trends in the automotive industry show growing demands for the introduction of new in-vehicle features (e.g., smart-phone integration, adaptive cruise control, etc.) at increasing rates and with reduced time-to-market. New technological developments (e.g., in-vehicle Ethernet, multi-core technologies, AUTOSAR standardized software architectures, smart video and radar sensors, etc.) provide opportunities as well as challenges to automotive designers for introducing and implementing new features at lower costs, and with increased safety and security. As a result, the design of Electrical/Electronic (E/E) architectures is becoming increasingly challenging as several hardware resources are needed. In our earlier work, we have provided top-level definitions for three relevant metrics that can be used to evaluate E/E architecture alternatives in the early stages of the design process: flexibility, scalability and expandability.
2011-04-12
Technical Paper
2011-01-0421
V. A. Muruganandam, Maruthi Dhulipudi, Uday Korde
Coolant pipes are a prime connection units present in any engines that facilitates the flow of coolant and thereby keeping the engine under its optimum operating condition. Among the several influencing factors that deteriorate engines performance, the coolant leak is also one of the contributors. This could be caused primly due to leakage issues that arises from the pipe press fit zones. Henceforth it is very important to understand the root cause of this press-fit connection failure. The present study deals with press-fit between the pipe and housing in an engine which is subjected to extreme thermal loads (min of -40°C to a max temperature of +150°C) thereby causing the press-fit loosening effect.
2011-04-12
Technical Paper
2011-01-0411
H Pandarinath, J Sureshkumar, Ramalingam Sivanantham, S Prabhakar, S R Nagendiran
Vacuum pumps are predominantly used in diesel engines of passenger cars and trucks for generating vacuum in servo brake applications. With the emission norms getting stringent, there is a need for vacuum signal for EGR actuation, turbo-charger waste gate actuation and other servo applications. These multi-functional applications of vacuum pumps and the functional criticality in application like braking system demand an effective and reliable performance. In gasoline engines, the vacuum generated in the intake manifold is tapped for braking. The recent technology of gasoline direct injection compels the use of vacuum pump in gasoline engines also due to scarce vacuum in intake manifold. The performance of the vacuum pump is highly dependent on the opening and closing of the check valve sub-system, which is positioned between the vacuum reservoir and the pump at the suction side.
2011-04-12
Technical Paper
2011-01-0690
Withit Chatlatanagulchai, Kittipong Yaovaja, Shinapat Rhienprayoon, Krisada Wannatong
Knock behavior in diesel-dual-fuel (DDF) engine is more complex, more severe, and different than those of traditional engines. We investigate a type of diesel-dual-fuel engines, where CNG is multipoint-injected at the intake ports as main fuel and diesel is directly injected in smaller amount, mainly for ignition purpose, resulting in lower fuel cost. Because of the mixed behaviors between the spark ignited and compression ignited engines, a more sophisticated control system is needed to properly control knock in the DDF engine. In this paper, a novel control system based on fuzzy logic is presented to regulate knock intensity at an appropriate level. The control system comprises a fuzzy controller and a fuzzy decision maker. The fuzzy controller controls several pertaining actuators using rule-base from human experience, while the fuzzy decision maker adapts the magnitude of each actuator action to various operating points.
2011-04-12
Technical Paper
2011-01-0667
Ramesh Rebba, Jeong Hun Seo, Ann Marie Sastry, Mary Fortier
Rechargeable energy storage systems with Lithium-ion pouch cells are subject to various ambient temperature conditions and go through thousands of charge-discharge cycles during the life time of operation. The cells may change their thickness with internal heat generation, cycling and any other mechanisms. The stacked prismatic cells thus experience face pressure and this could impact the pack electrical performance. The pack consists of stiff end plates keeping the pack in tact using bolts, cooling fins to maintain cell temperature and foam padding in between cells. The pack level thermal requirements limit the amount of temperature increase during normal operating conditions. Similarly, the structural requirements state that the stresses and the deflection in the end plates should be minimal. Uncertainties in cell, foam mechanical and thermal properties might add variation to the pack performance.
2011-04-12
Technical Paper
2011-01-0658
Juan Carlos Martinez Laurent
With the constant need to meet new environmental regulations, the improvement of automotive exhaust systems technologies to be cleaner and more effective is a necessity. To achieve these regulations the automakers have been focused on the development of better particle filters and more effective cleaning processes. Catalyst Oxidation and Diesel Particle Filter Regeneration are good and effective techniques to accomplish these objectives but the amount of heat generated by these processes is a concern in the thermal management of the vehicle. To gain a better understanding of these effects Finite Element Thermal Analysis has proved to be a useful tool to predict and observe the increment of temperature during these processes. This work is focus on a simulation process using several 1-D and 3-D techniques to predict the skin exhaust temperature during the regeneration process moment in which the system achieve the maximum temperature.
2011-04-12
Journal Article
2011-01-0019
Kyoo Sil Choi, Ayoub Soulami, Wenning Liu, Xin Sun, Moe Khaleel
In this paper, the microstructure-based finite element modeling method is used in investigating the loading path dependence of formability of transformation induced plasticity (TRIP) steels. For this purpose, the effects of different loading path on the forming limit diagrams (FLD) of TRIP steels are qualitatively examined using the representative volume element (RVE) of a commercial TRIP800 steel. First, the modeling method was introduced, where a combined isotropic/kinematic hardening rule is adopted for the constituent phases in order to correctly describe the cyclic deformation behaviors of TRIP steels during the forming process with combined loading paths which may include the unloading between the two consecutive loadings. Material parameters for the constituent phases remained the same as those in the authors' previous study [ 1 ] except for some adjustments for the martensite phase due to the introduction of the new combined hardening rule.
2011-04-12
Journal Article
2011-01-0218
Johnson Joseph, S Raja, Y Charles Lu
Piezoelectric materials are smart materials that can undergo mechanical deformation when electrically or thermally activated. An electric voltage is generated on the surfaces when a piezoelectric material is subjected to a mechanical stress. This is referred to as the ‘direct effect’ and finds application as sensors. The external geometric form of this material changes when it is subjected to an applied voltage, known as ‘converse effect’ and has been employed in the actuator technology. Such piezoelectric actuators generate enormous forces and make highly precise movements that are extremely rapid, usually in the micrometer range. The current work is focused towards the realization and hence application of the actuator technology based on piezoelectric actuation. Finite element simulations are performed on different types of piezoelectric actuations to understand the working principle of various actuators.
2011-04-12
Journal Article
2011-01-0228
Anthony George Konstantino, Mark A. Levine
This paper summarizes the Fast Fourier Transform (FFT) methodology, special equipment, set-up and testing that is recommended to properly characterize the surface of bearing journals that will not result in objectionable noise or vibration. Traditional surface profiles and finish callouts do not capture some of the key characteristics for addressing what is often the customer's greatest complaint, noise. Noise can vary based on the sensitivity of the vehicle but understanding how to accurately describe (design, test, and measure) a surface for a given vehicle can result in an optimized design and reduce process time during manufacturing. Furthermore, this paper will recommend techniques for determining the proper limits of the FFT callouts.
2011-04-12
Technical Paper
2011-01-0199
Thomas Christiner, Wilfried Eichlseder, Istvan Gódor, Johannes Reiser, Franz Trieb, René Stuehlinger
Recent trends in mechanical engineering are focusing on optimization of components with respect both to weight and lifetime by using numerical simulation even in the early design stages. For a reliable prediction of in service performance by simulation, both loading as well as different damage and failure mechanisms that may be activated during operation have to be known. In mechanical engineering applications, cyclic loadings are most common. In many assemblies of moving components, contact problems under various lubrication conditions are lifetime-limiting. There, relative motion of contacting bodies combined with high loads transmitted via the contact surface lead to fretting fatigue failure. In this contribution a few selected results of a currently conducted research project are presented. The aim of this study was to examine the material behavior of a surface stressed steel. The influence of the Fretting regime on fatigue properties has been investigated.
2011-04-12
Technical Paper
2011-01-0186
Manfred Baecker, Axel Gallrein, Michael Hack, Alessandro Toso
During the last ten years, there is a significant tendency in automotive design to use lower aspect ratio tires and meanwhile also more and more run-flat tires. In appropriate publications, the influences of these tire types on the dynamic loads - transferred from the road passing wheel center into the car - have been investigated pretty well, including comparative wheel force transducer measurements as well as simulation results. It could be shown that the fatigue input into the vehicle tends to increase when using low aspect ratio tires and particularly when using run-flat tires. But which influences do we get for the loading and fatigue behavior of the respective rims? While the influences on the vehicle are relatively easy to detect by using wheel force transducers, the local forces acting on the rim flange (when for example passing a high obstacle) are much more difficult to detect (in measurement as well as in simulation).
2011-04-12
Technical Paper
2011-01-0184
Jianfeng Ma, Joshua Summers, Paul Joseph
In this paper, the Finite Element Method (FEM) is used to model and simulate the dynamic interaction between non-pneumatic tire and sand with obstacle to investigate the influence of obstacle on performance of the non-pneumatic tire. The non-pneumatic tire consists of three major components: two inextensible circumferential membranes, a critical shear beam, and a group of deformable spokes. The non-pneumatic tire fabricated of segmented cylinders is illustrated and the FEM model for the tire is given in detail. The tire is treated as an elastic deformable body with the inertia effect included. Lebanon sand found in New Hampshire is used in this simulation because of the availability of a complete set of material properties in the literature. Modified Drucker-Prager/Cap plasticity constitutive law with hardening is utilized to model the sand. The obstacle is represented as an elastic body.
2011-04-12
Technical Paper
2011-01-0099
Kwangwon Kim, Doo Man Kim
A Non-Pneumatic Tire (NPT) appears to have advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. In this study, the static contact pressure of NPTs with hexagonal honeycomb spokes is investigated as a function of vertical loading and is compared with that of a pneumatic tire. Finite element based numerical simulation of the 2D contact pressure of a NPT is carried out with ABAQUS for varying vertical forces and lattice spoke geometries. A lower contact pressure is obtained with NPTs than with the pneumatic tire due to a high lateral spoke stiffness of NPTs when they are designed to be the same load carrying capability. The NPT with the spoke of a low cell angle, Type A spoke in this study, shows a low contact pressure; Type A in this study. On the other hand, the NPT with Type C spoke shows a lower local stress in the spoke cell struts, associated with the flexible cellular structural property in the uni-axial compression.
2011-04-12
Journal Article
2011-01-0058
Giles Bryer, Christopher Eccles
As mass reduction becomes an increasingly important enabler for fuel economy improvement, having a robust structural development process that can comprehend Vehicle Dynamics-specific requirements is correspondingly important. There is a correlation between the stiffness of the body structure and the performance of the vehicle when evaluated for ride and handling. However, an unconstrained approach to body stiffening will result in an overly-massive body structure. In this paper, the authors employ loads generated from simulation of quasi-static and dynamic vehicle events in ADAMS, and exercise structural finite element models to recover displacements and deflected shapes. In doing so, a quantitative basis for considering structural vehicle dynamics requirements can be established early in the design/development process.
2011-04-12
Technical Paper
2011-01-0695
Hossein Javaherian, Alan W. Brown, Michael P. Nolan
A frequency-domain approach to balancing of air-fuel ratio (A/F) in a multi-cylinder engine is described. The technique utilizes information from a single Wide-Range Air-Fuel ratio (WRAF) or a single switching (production) O₂ sensor installed in the exhaust manifold of an internal combustion engine to eliminate the imbalances. At the core of the proposed approach is the development of a simple novel method for the characterization of A/F imbalances among the cylinders. The proposed approach provides a direct objective metric for the characterization of the degree of A/F imbalances for diagnostic purposes as well as a methodology for the control of A/F imbalances among various cylinders. The fundamental computational requirement is based on the calculation of a Discrete Fourier Transform (DFT) of the A/F signal as measured by a WRAF or a switching O₂ sensor.
2011-04-12
Technical Paper
2011-01-0507
Shuming Chen, Dengfeng Wang, Wei Li, Jianming Zan
For the purpose of predicting the interior noise of a passenger automobile at middle and high frequency, an energy finite element analysis (EFEA) model of the automobile was created using EFEA method. The excitations including engine mount excitation and road excitation were measured by road experiment at a speed of 120 km/h. The sound excitation was measured in a semi-anechoic chamber. And the wind excitation was calculated utilizing numeric computation method of computational fluid dynamics (CFD). The sound pressure level (SPL) and energy density contours of the interior acoustic cavity of the automobile were presented at 2000 Hz. Meanwhile, the flexural energy density and flexural velocity of body plates were calculated. The SPL of interior noise was predicted and compared with the corresponding value of experiment.
2011-04-12
Journal Article
2011-01-0506
Sangyun Lee, Kwangseo Park, Shung H. Sung, Donald J. Nefske
Three different acoustic finite element models of an automobile passenger compartment are developed and experimentally assessed. The three different models are a traditional model, an improved model, and an optimized model. The traditional model represents the passenger and trunk compartment cavities and the coupling between them through the rear seat cavity. The improved model includes traditional acoustic models of the passenger and trunk compartments, as well as equivalent-acoustic finite element models of the front and rear seats, parcel shelf, door volumes, instrument panel, and trunk wheel well volume. An optimized version of the improved acoustic model is developed by modifying the equivalent-acoustic properties. Modal analysis tests of a vehicle were conducted using loudspeaker excitation to identify the compartment cavity modes and sound pressure response to 500 Hz to assess the accuracy of the acoustic models.
2011-04-12
Technical Paper
2011-01-0510
Megumu Oshima, Kanya Nara, Tatsuhiko Yoshimura
We have constructed a design review system in which Full Process and Quick Design Review processes are selectively used according to the degree of newness in a design change. The Full Process Design Review is conducted for a review of system or part designs having a high level of newness and the tools and process used in this review were standardized. The Quick Design Review is newly developed design review process that could be conducted in a quicker and simpler manner for designs involving a medium level of newness in order to effectively prevent design-related problems. The Quick Design Review uses a changes list and Design Review Based on Failure Mode (DRBFM) [1] worksheets to focus on the changed points. This method enables the engineers involved to identify problems and to devise solutions efficiently and effectively through discussions.
2011-04-12
Journal Article
2011-01-0529
Sujit Chalipat, Ganesh Radha, Adwait Kulkarni, Rahul Mahajan
Passive safety regulations specify minimum safety performance requirements of vehicle in terms of protecting its occupants and other road users in accident scenarios. Currently for majority cases, the compliance of vehicle design to passive safety regulations is assessed through physical testing. With increased number of products and more comprehensive passive safety requirements, the complexity of certification is getting challenged due to high cost involved in prototype parts and the market pressures for early product introduction through reduced product development timelines. One of the ways for addressing this challenge is to promote CAE based certification of vehicle designs for regulatory compliance. Since accuracy of CAE predictions have improved over a period of time, such an approach is accepted for few regulations like ECE-R 66/01, AIS069 etc which involves only loadings of the structures.
2011-04-12
Technical Paper
2011-01-0476
Philip J. Bates, Gene Zak, Xiaochao Cao
In Laser Transmission Welding (LTW), a laser beam passes through a transparent part and is dissipated as heat in an absorbent material through the use of laser-absorbing pigments such as carbon black (CB). This energy is then conducted further into both parts. Melting and subsequent solidification occur at the interface causing a weld to form between the two parts. Gluing or welding structures to the back of automotive Class-A panels often results in the appearance of undesirable surface deformations on the Class-A side. Through control of the laser welding and material parameters, it may be possible to use contour LTW as a means of joining structures to the back of absorbent Class-A panels without creating these unwanted surface defects. A series of lap welds was made using a range of CB levels and laser powers. A profilometer was used to measure the size and shape of the defects generated on the surface of the black part. Two types of defects were observed: ribs and sink marks.
2011-04-12
Technical Paper
2011-01-0496
Shung Sung, Sung Chao, Hari Lingala, Lee Mundy
A structural-acoustic finite element model of an automotive vehicle is developed and applied to evaluate the effect of structural and acoustic modifications to reduce low-frequency ‘boom’ noise in the passenger compartment. The structural-acoustic model is developed from a trimmed body structural model that is coupled with an acoustic model of the passenger compartment and trunk cavities. The interior noise response is computed for shaker excitation loads at the powertrain mount attachment locations on the body. The body panel and modal participation diagrams at the peak response frequencies are evaluated. A polar diagram identifies the dominant body panel contributions to the ‘boom’ noise. A modal participation diagram determines the body modes that contribute to the ‘boom’ noise. Finally, structural and acoustic modifications are evaluated to determine their effect on reducing the ‘boom’ noise and on the overall lower-frequency sound pressure level response.
2010-04-12
Technical Paper
2010-01-0849
Ahmad Fadel, Biao Zhou
The implementation of fuel cell-battery hybrid vehicles requires a supervisory control strategy that manages the power distribution between the fuel cell and the energy storage device (i.e., battery). Several advanced control methods have already been developed and published in literature. However, most control methods have been developed for different vehicle types and using different mathematical models. The performance of these power management methods have not been directly compared for the same application. This study aims at obtaining direct analytical comparisons, which will provide useful insight in selecting a power management method for fuel cell-battery hybrid vehicles.
2013-05-13
Journal Article
2013-01-1961
Eric Frank, Chris Moon, Jason Rae, Michael Popovich
As the interior sound levels in cabin compartments of passenger vehicles continue to get quieter, noises from various sources which previously were not objectionable can become an issue. One such source is the “slosh noise” from liquid movement within fuel tanks. Vehicle manufacturers, responding to the phenomena, have turned to their suppliers and worked with them to establish robust test and analysis methods to characterize the NVH performance of their fuel storage and delivery systems. Test facilities have recently made great advancements in the capability to measure and characterize “fuel slosh noise” in tanks. However, the industry today lacks standardized procedures to apply to the issue, including defining test parameters and analysis methods (both of which are complex because of the time-domain nature of slosh events).
2013-05-13
Technical Paper
2013-01-1959
Filip Nauwelaerts, David Moens, Kristof Harri
When qualifying prototype samples in terms of vibration response and dynamic characteristics, an accredited laboratory is required to implement monitoring procedures to assure the validity of the test results. According to ISO17025, such monitoring may include inter-laboratory comparison or proficiency testing. This paper presents a mechanical structure which has been designed specifically to be used as a generic reference sample during such a comparative study in which resonant frequencies of a structure need to be quantified. This paper elaborates on the analysis and design issues, which encompass theoretical analysis, both purely mathematical and by FEM (Finite Element Modeling). In addition, to allow statistical analysis of test data resulting from measurements performed by different test laboratories, the uncertainty budget [1] of the reference value of this sample is determined.
2013-05-13
Technical Paper
2013-01-1998
Nickolas Vlahopoulos, Geng Zhang, Walter Brophy, Madhan Ramaswami
The Energy Finite Element Analysis (EFEA) has been developed for computing the structural vibration and the interior noise level of complex structural-acoustic systems by solving numerically governing differential equations with energy densities as primary variables. In this paper a complete simulation process for evaluating airborne noise in an automotive vehicle is presented and validated through extensive comparison to test data. The theoretical elements associated with the important paths of the noise transfer from the exterior of the vehicle to the interior acoustic space are discussed. The steps required for developing an EFEA model for a vehicle are presented. The model is developed based on the physical construction of the vehicle system and no test measurements are utilized for adjusting the numerical model.
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