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451.
Y. Shi I.- T. Lee A. Md. Afsar J.- I. Song 《International Journal of Automotive Technology》2009,10(4):481-488
As the number of disabled people grows, independence and mobility become a priority for those individuals. To achieve this
goal, a ‘Turny-type power seat’ was developed in this study to assist a disabled person rise from a vehicle without trouble.
The design and modeling of the power seat were performed using AutoCAD and CATIA software. The major motions of the power
seat system are swiveling, sliding, and extending, which are accomplished primarily by DC motors, chains, and gears. Most
of the power seat parts were made from mild steel. Welding technology was used throughout the frame fabrication. To ensure
the safety and stability of the power seat, various tests were performed, and the results analyzed. The static analysis of
the power seat was carried out by ANSYS 11.0. The results showed that the power seat conformed to the Americans with Disabilities
Act (ADA) standards. The durability test was performed by repeatedly rotating and sliding the power seat under loading conditions.
Dynamic crash simulation was carried out using the LS-DYNA software. The durability test ensured a longer life of the power
seat, while the crash analysis showed a small rotational distortion that was not harmful to passengers. However, the front
seat had a slightly larger forward displacement, which was not comfortable for passengers. Therefore, further modifications
of the power seat should be done to improve the performance, with attention given to the reduction of the forward displacement
in the event of a crash. 相似文献
452.
H. W. Lee S. H. Park M. W. Park N. G. Park 《International Journal of Automotive Technology》2009,10(4):459-467
A mathematical model of an automotive transmission is developed, that considers the flexibility of the shafts, bearings, and
gear teeth, and gyroscopic effects of geared rotors. The transverse, torsional, and axial motions are strongly coupled due
to helical gearing. The excitation forces acting on the automotive transmission are classified into first, second, and third
grades, based on the magnitudes of the forces that are determined by the perturbation method. The excitation forces are caused
by the mass imbalances among gears, misalignment of shafts, clearance and non-linear deformation of bearings, transmission
errors, and the periodic variation of the gear mesh stiffness. A bench test on loading conditions is carried out for the third
speed of the automotive transmission. The experimental results of vibration characteristics are compared with those from theoretical
analysis. The results show good agreement, i.e., within a tolerance of 3.3%. 相似文献
453.
K. -H. Moon S. -H. Lee S. Chang J. -K. Mok T. -W. Park 《International Journal of Automotive Technology》2009,10(4):441-449
Many methods we have been developed to control the rear wheels of a vehicle, but most of them are designed for automobiles
with four wheels. The AWS (all wheel steering) control method for articulated vehicles is currently applied only to Phileas
vehicles developed by APTS, but the control algorithm for this system has yet to be reported. In the present paper, a new
algorithm is proposed after the AWS ECU (electronic control unit) of the Phileas vehicle was tested and analyzed in order
to understand the existing steering algorithm. The new algorithm considers the vehicle geometry, stability of handling, and
safety, and can be easily applied to multi-axle vehicles. In order to verify the AWS algorithm, the trajectory and steering
angles of each algorithm were compared using the commercial software ADAMS. Turning radius, swing-out, and swept path width
were also investigated to determine the turning performance of the proposed algorithm. 相似文献
454.
W. Hong C. Choi W. Lee J. P. Hong D. Kum 《International Journal of Automotive Technology》2009,10(4):489-495
This paper proposes an advanced permanent magnet (PM) motor drive modeling for dynamic analysis of automotive control systems
with PM motor drives. To enhance the reusability of the proposed PM motor drive model, each component is modeled in an object-oriented
manner according to the physical partitioning of a real drive system, and userfriendly and well-organized interfaces are also
proposed. These characteristics enable this model to be used as a kind of a programming library. A multi-level modeling strategy
is also proposed, which helps make a compromise between model accuracy and simulation speed without structural modification
of the system model. The model and modeling strategy developed allow for a comprehensive analysis of each component and dynamic
analysis of the total system. System simulation results show the practical effectiveness of the proposed modeling strategy. 相似文献
455.
U. B. Azimov K. S. Kim D. S. Jeong Y. G. Lee 《International Journal of Automotive Technology》2009,10(3):265-276
The concept of Low Temperature Combustion (LTC) has been advancing rapidly because it may reduce emissions of NOx and soot
simultaneously. Various LTC regimes that yield specific emissions have been investigated by a great number of experiments.
To accelerate the evaluation of the spray combustion characteristics of LTC, to identify the soot formation threshold in LTC,
and to implement the LTC concept in real diesel engines, LTC is modeled and simulated. However, since the physics of LTC is
rather complex, it has been a challenge to precisely compute LTC regimes by applying the available diesel combustion models
and considering all spatial and temporal characteristics as well as local properties of LTC. In this paper, LTC regimes in
a constant-volume chamber with n-Heptane fuel were simulated using the ECFM3Z model implemented in a commercial STAR-CD code.
The simulations were performed for different ambient gas O2 concentrations, ambient gas temperatures and injection pressures. The simulation results showed very good agreement with
available experimental data, including similar trends in autoignition and flame evolution. In the selected range of ambient
temperatures and O2 concentrations, soot and NOx emissions were simultaneously reduced. 相似文献
456.
C. L. Myung H. Lee K. Choi Y. J. Lee S. Park 《International Journal of Automotive Technology》2009,10(5):537-544
This study was focused on experimental comparisons of the effects of various vehicle certification modes on particle emission
characteristics of light-duty vehicles with gasoline, diesel, LPG, and low-carbon fuels such as bio-diesel, bioethanol, and
compressed natural gas, respectively. The particulate matter from various fueled vehicles was analyzed with the golden particle
measurement system recommended by the particle measurement programme, which consists of CVS, a particle number counter, and
particle number diluters. To verify particle number and size distribution characteristics, various vehicle emission certification
modes such as NEDC, FTP-75, and HWFET were compared to evaluate particle formation with both CPC and DMS500. The formation
of particles was highly dependent on vehicle speed and load conditions for each mode. In particular, the particle numbers
of conventional fuels and low-carbon fuels sharply increased during cold start, fast transient acceleration, and high-load
operation phases of the vehicle emission tests. A diesel vehicle fitted with a particulate filter showed substantial reduction
of particulate matter with a number concentration equivalent to gasoline and LPG fuel. Moreover, bio-fuels and natural gas
have the potential to reduce the particulate emissions with the help of clean combustion and low-carbon fuel quality compared
to non-DPF diesel-fueled vehicles. 相似文献
457.
公路管理机构常用动态测重技术(WIM)来减少车辆滞留和执行超重车辆通行法.一般的做法是采用固定阈值(即合法重量极值)来初步过滤和分类车辆.如果某卡车的动态测重读数超过该阈值,该卡车会被指示去静态测重作进一步的检查,如:超重属实则可能开出处罚传票.适应性测重阈值法能充分利用动态测重技术并增强其操作效率.当在测重站等候的车辆很多时,阈值将增大,以避免测站阻塞,同时仍然可以逮住严重超重的违规车辆.当等候车辆少时,该阈值降低,以尽量多地检查车辆.主要阐述对适应性测重法的操作和设计的估算,并建立了一个高速路匝道出口动态测重站的微观模拟模型.然后,模拟和测试了动态阈值调节策略.结果表明,在广泛的条件下,适应性法总是优于传统的静态阈值操作法.在交通流量需求很大条件下,该算法抓住的超重卡车比静态操作的多44%以上,同时,其平均车辆滞留只为在静态操作情况下的30%.换句话说,所提出的适应性测重法更有效地控制了超重并满足了交通流量的要求. 相似文献
458.
Partial range scaling method based washout algorithm for a vehicle driving simulator and its evaluation 总被引:2,自引:0,他引:2
M. S. Kim Y. G. Moon G. D. Kim M. C. Lee 《International Journal of Automotive Technology》2010,11(2):269-275
Unlike an actual vehicle, a vehicle driving simulator (VDS) has limited kinematics, workspace, and bounded dynamic characteristics
making it very difficult to simulate dynamic motions of an actual vehicle. To solve these problems, a washout algorithm was
developed. The developed algorithm restricts the workspace of the VDS to within the kinematic limit and makes the person driving
the VDS perceive movement of an actual vehicle. However, the classic washout algorithm contains several problems, such as
time delay and the generation of a wrong motion signal caused by characteristics of the filters. So the driver feels “simulator
sickness,” such as fatigue, nausea, headache and so on because of differences between the sense of movement of the VDS and
that of a real vehicle. In this paper, a partial range scaling method based washout algorithm, including a tilt coordination
system, is developed to enhance the perception of motion and reduce simulator sickness. It is verified by a simulation, a
survey, and a bio signal analysis using an electrocardiogram (ECG). 相似文献
459.
S. I. Kim G. H. Lee J. J. Lee J. P. Hong 《International Journal of Automotive Technology》2010,11(2):277-282
In this paper, a simple design method for improving the performance of an interior permanent magnet synchronous motor (IPMSM),
for driving the air-conditioning compressor used in hybrid electric vehicles, is presented. There are many design methods
that optimize the IPMSM. Each method deals with a variety of design factors, such as slot opening, pole arc, and rotor shape.
However, as the number of design variables increases, a lot of modeling and analysis time is needed in order to improve the
characteristics of an IPMSM. This paper demonstrates that the optimization of a double-layer IPMSM, satisfying the given design
conditions, is possible with only a flux barrier shape design. Then, response surface methodology is applied as the optimization
method, and the validity of the design approach is verified by comparison with test results. 相似文献
460.
There has been recent interest in a new engine type, Homogeneous Charge Compression Ignition (HCCI), to combine the advantages
of SI and CI engines. In this paper, a locally deterministic approach is employed to consider spatial inhomogeneities using
the KIVA-CHEMKIN package. Validation is performed for two experimental HCCI engines fueled, respectively, by hydrogen and
n-heptane. The full mechanism for hydrogen and a skeletal mechanism for n-heptane are used for combustion chemistry. Differences
in the reaction flow paths are shown at ignition and the heat release reaction stages of the two fuels. Results show good
agreement between measured and calculated pressures for different initial mixture temperatures with estimated residual fractions.
A parametric study is performed in both engines to consider the influences of the physical parameters wall temperature, swirl
ratio and global equivalence ratio. The ignition time of n-heptane is shown to be relatively insensitive to variations in
these parametric due to its two-stage ignition behavior. 相似文献