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11.
K. Jeon H. Hwang S. Choi J. Kim K. Jang K. Yi 《International Journal of Automotive Technology》2012,13(2):247-253
Cornering maneuvers with reduced body roll and without loss in comfort are leading requirements for car manufacturers. An
electric active roll control (ARC) system controls body roll angle with motor-driven actuators installed in the centers of
the front and rear stabilizer bars. A vehicle analysis model developed using a CarSim S/W was validated using vehicle test
data. Two ARC algorithms for a sports utility vehicle (SUV) were designed using a sliding-mode control algorithm based on
a nonlinear roll model and an estimated lateral acceleration based on a linearized roll model. Co-simulation with the Matlab
simulink controller model and the CarSim vehicle model were conducted to evaluate the performance of two ARC control algorithms.
To validate the ARC performance in a real vehicle, vehicle tests were conducted at KATECH proving ground using a small SUV
equipped with two ARC actuators, upper and lower controllers and a few subsystems. From the simulation and vehicle validation
test results, the proposed ARC control algorithm for the developed ARC actuator prototypes improves the vehicle’s dynamic
performance. 相似文献
12.
J. -K. Kim E. S. Yim C. H. Jeon C. -S. Jung B. H. Han 《International Journal of Automotive Technology》2012,13(2):293-300
This study examines the cold performance of biodiesel blends in a passenger car and a light duty truck at −16 °C and −20 °C.
Six different types of biodiesels derived from soybean oil, waste cooking oil, rapeseed oil, cottonseed oil, palm oil and
jatropha oil were blended with different volume ratios (B5 (5 vol. % biodiesel — 95 vol. % diesel), B10 and B20). The cold
filter plugging point (CFPP) and the cloud point had an effect on the startability and driveability of both the passenger
car and the light duty truck. The startability and driveability of the passenger car with all biodiesel blends (B5) were generally
good at −20 °C. In the light duty truck, biodiesel blends (B10 and B20) of soybean, waste cooking, rapeseed and jatropha tended
to be good at −20 °C in the startability and driveability tests than the biodiesel blends (B10 and B20) of cottonseed and
palm. In particular, the palm biodiesel blend (B10) failed at −20 °C, and the palm biodiesel blend (B20) also failed at −16
°C in the startability test. The cold flow properties of biodiesel dictate that the length of the hydrocarbon chains and the
presence of unsaturated structures significantly affect the low temperature properties of biodiesel. 相似文献
13.
N. G. Park J. H. Ryu H. W. Lee Y. H. Jeon N. Zhang 《International Journal of Automotive Technology》2009,10(3):341-346
An Inner Spherical CVT (ISCVT) transfers engine power by utilizing the traction force of the lubricant fluid film on the contact
point between concave and convex spherical rolling bodies. Since the concave and the convex contact surfaces of the ISCVT
are exactly spherical parts, they have a large circular (not elliptic) contact area, and the ISCVT mechanism has a larger
torque capacity, less spin loss, and better stability than other traction drive mechanisms. The IVT (Infinitely Variable Transmission)
performances also can easily be embodied in the ISCVT. In this work, we developed a prototype of the ISCVT for a motorcycle
with a 125cc single cylinder engine having a maximum torque of 13.73 Nm at 8,000 rpm. The design parameters were determined,
and the transmission performances were evaluated by optimal design procedure. The transmission efficiency, the life time,
the maximum severe stresses on each part of the ISCVT, and the work needed for varying speed ratio were theoretically investigated,
and the efficiency performances were experimentally measured. The manufactured prototype was installed in an actual motorcycle,
which was fixed on the test-bench equipped with a dynamometer. The parasitic loss of the prototype and the cross-sectional
road load performance were tested. The power efficiency of the simulated prototype was between 87∼92%, and the life span was
more than 50,000 hours. The tested overall power efficiency was around 70∼92% under frequent driving conditions, which is
an impressive performance in a motorcycle transmission despite the small difference from the simulation. 相似文献
14.
B. -L. Choi D. -H. Choi J. Min K. Jeon J. Park S. Choi J. -M. Ko 《International Journal of Automotive Technology》2009,10(1):49-54
This research proposes an automatic torsion beam axle optimization process with a multidisciplinary approach and generates
the optimal torsion design parameters, such as thickness and shape. In order to construct an automatic analysis process, multidisciplinary
analysis models, such as modal analysis, roll mode dynamic analysis, and fatigue analysis, were applied in batch mode. To
understand the design space, a parametric study using the torsion beam thickness and shape was performed. Considering roll
durability and K&C characteristics, the torsion beam axle could be optimized. For the automated design process, a PIDO tool
called PIAnO was used. In conclusion, a reduction in the computer-aided simulation time was achieved, and the durability and
K&C characteristics of the torsion beam were enhanced by optimizing the thickness and shape. 相似文献
15.
This paper investigates the centrality of cruise ports in the Asian cruise shipping market while proposing the hubs and authorities centrality (HACC) metric as a directional synthesis of the hubs centrality and authorities centrality to explore cyclical and directional features of centrality in the cruise shipping network. With the development of the cruise shipping industry, research has been actively conducted with a particular focus on identifying the characteristics of hub ports. This paper employs social network analysis to investigate the HACC which is originally developed for analyzing the cruise port centrality problem. Empirical study implies that Ho Chi Minh City, Hong Kong, Nagasaki, Penang, Phuket, Port Klang, Shanghai, and Singapore (in alphabetical order) reflects particulars of cruise hub ports. One of the exceptional results of this paper is Ho Chi Minh City, Penang, Phuket, and Port Klang have demonstrated high HACC (refers to hub ports) while limited degree and betweenness centrality. In contrast, Busan and Keelung are not classified as hub ports. 相似文献
16.
Seokcheon Jeon Jinseong Kim Sun Woo Jin Kyuyeol Koak Eun Jun Rhee Chibum Lee Yeong-il Park 《International Journal of Automotive Technology》2018,19(4):677-685
The present study has focused on the comparison of MR damper dynamic models for the purpose of hardware in the loop simulation. A vehicle dynamic model for large-sized bus and a control logic for MR damper was built. Two typical MR damper models, viz. Bouc-Wen and hyperbolic tangent model have been considered in this study and the advantages and disadvantages of each model on the aspect of HILS system is discussed. We discussed the limitations of each model based on the analysis of the vehicle dynamic simulation. The results showed that the existing models are not suitable for HILS system. We proposed the modified hyperbolic tangent model by adopting low-pass filters. The results from the simulation showed the advantages of the modified model which were validated through HILS system. 相似文献
17.
YunSik Yang YoungShin Kim EuySik Jeon 《International Journal of Automotive Technology》2018,19(6):1041-1048
Whiplash injuries are one of the most common injuries reported in automotive rear end collisions. Automobile seat back and head restraints play a role in reducing neck injuries during low speed rear end collisions. Currently, many studies are being conducted on ways to reduce neck injuries. These deal with the design parameters that cause neck injuries and do not address the design of the head restraint connection structure. In this paper, we analyze the various trajectories of the headrest and propose a new design for a connection structure that can move along the corresponding trajectory. We model the headrest connection mechanism as a virtual link using kinematic modeling and perform trajectory analysis. Using the trajectory of motion, we select an oblong shape for the guide slot by fitting it with the equation of an ellipse and propose a new headrest connection mechanism. To evaluate the design of the proposed mechanism, we model the shape of the mechanism and test it using dynamic simulation under collision conditions. In addition, we design a prototype for the proposed guide, conduct a sled test, and confirm that the neck force is reduced by the proposed connection structure. In the proposed structure, the values of maximum upper neck shear and tension decreased by more than 20 % compared to existing headrest. 相似文献
18.
S. -J. Kim W. -J. Jeon J. -J. Park B. -S. Moon Y. -J. Cho Y. -I. Seo N. -K. Park K. Son 《International Journal of Automotive Technology》2011,12(6):951-958
A perturbation mark is occasionally produced on the velocity indicator of the cluster panel of a vehicle during a vehicle
collision. This mark can be used to estimate the velocity of the vehicle at the moment of the vehicle’s impact. In this study,
the effect of the impact velocity and the deceleration of the vehicle on the perturbation mark were investigated, and an analysis
of the driver’s injury was also conducted through a numerical pulse representation and computer simulations. Sled and pendulum
tests were used to replicate the conditions that produce a perturbation mark on the velocity indicator of a cluster panel.
It was verified that a higher peak acceleration is more likely than the impact velocity to cause a perturbation mark. According
to the computer simulation results, a driver’s injury could be more severe at higher peak accelerations with a constant impact
velocity. If a perturbation mark, which can be used to estimate the impact velocity, is found while investigating a vehicle
accident, this mark reveals that the acceleration was higher than that listed in the related crash report. Therefore, the
injuries of the occupants could be more serious than those expected at the reported impact velocity. 相似文献
19.
Lane changes occur as many times as turning movements are needed while following a designated path. The cost of a route with many lane changes is likely to be more expensive than that with less lane changes, and unrealistic paths with impractical lane changes should be avoided for drivers' safety. In this regard, a new algorithm is developed in this study to find the realistic shortest path considering lane changing. The proposed algorithm is a modified link‐labeling Dijkstra algorithm considering the effective lane‐changing time that is a parametric function of the prevailing travel speed and traffic density. The parameters were estimated using microscopic traffic simulation data, and the numerical test demonstrated the performance of the proposed algorithm. It was found that the magnitude of the effect of the effective lane‐changing time on determining the realistic shortest path is nontrivial, and the proposed algorithm has capability to exclude links successfully where the required lane changes are practically impossible. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
20.
Learning-based traffic control algorithms have recently been explored as an alternative to existing traffic control logics. The reinforcement learning (RL) algorithm is being spotlighted in the field of adaptive traffic signal control. However, no report has described the implementation of an RL-based algorithm in an actual intersection. Most previous RL studies adopted conventional traffic parameters, such as delays and queue lengths to represent a traffic state, which cannot be exactly measured on-site in real time. Furthermore, the traffic parameters cannot fully account for the complexity of an actual traffic state. The present study suggests a novel artificial intelligence that uses only video images of an intersection to represent its traffic state rather than using handcrafted features. In simulation experiments using a real intersection, consecutive aerial video frames fully addressed the traffic state of an independent four-legged intersection, and an image-based RL model outperformed both the actual operation of fixed signals and a fully actuated operation. 相似文献