• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.299-304
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• 2003

The design of an occupant protection equipment has been considered as the important process in developing a new car since the crash performance plays an important role on the market. The cost is increased when an unexpected real test is carried out in the proto-design stage. Thus, the exact prediction of a crash performance can reduce the number of full-car test. In this research, the robust design of an airbag system considering the frontal crash is suggested to predict the more reliable responses. On the contrary, most existing researches do not consider the uncertainties. The uncertainties treated in this research are the tolerances of the vent hole, the time to fire and the length of a strap in airbag and the tolerance of the load limiter load in seat belt. The Taguchi method is utilized to determine the robust optimum of each parameter

• Journal of Welding and Joining
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• v.15 no.4
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• pp.143-153
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• 1997

In this study, bending test was performed on the real-scale, built-up beam test model fabricated by the $CO_2$ arc spot welding to evaluate the applicability of the welding method to the production of the stiffened plate in car-carrying ship. The built-up beam models which were fixed at both ends in longitudinal direction or simply supported to the rigid foundation, depending on the restraint condition of the corresponding car decks considered, were subjected to simulated design vehicle loads or concentrated point loads. During the test, the central deflection and the longitudinal bending stresses were measured from several points on the longitudinal flange face to predict the section properties of the built-up beams. The longitudinal bending stress on each spot weld were also measured to calculate the average horizontal shear force subjected to spot welds. Test results revealed that the shear strength of spot welds with their current weld nugget size and welding pitch was adequate enough to withstand the horizontal shear forces under the design vehicle loads. Although the built-up beam fabricated by the arc spot welding was a discontinuous beam, its mechanical behavior was well explained by the continuous beam theory using the effective breadth of plate. Based on test results, the criterion for the size of spot weld of which the average shear stress might meet the allowable stress requirement of AWS Code could be established.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.823-830
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• 2009

For developing automotive parts and telematics devices the real car test often shows limitation because it needs high cost, much time and has the possibility of the accident. Therefore, a Vehicle Driving Simulator (VDS) instead of the real-car test has been used by some automotive manufactures, research centers, and universities. The VDS is a virtual reality device which makes a human being feel as if one drives a vehicle actually. Unlike actual vehicle, the simulator has limited kinematic workspace and bounded dynamic characteristics. So it is difficult to simulate dynamic motions of a multi-body vehicle model fully. In order to overcome these problems, a washout algorithm which restricts workspace of the simulator within the kinematic limits is needed, and analysis of dynamic characteristics is required also. However, a classical washout algorithm contains several problems such as time delay and generation of wrong motion signal caused by characteristics of filters. Specially, the classical washout algorithm has the simulator sickness when driver hardly turns brakes and accelerates the VDS. In this paper, a new washout algorithm is developed to enhance the motion sensitivity and improve the simulator sickness by using the vehicle tilt signal which is generated in the real time vehicle dynamic model.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.910-917
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• 2011

CBTC(Communication Based Train Control) car-borne equipment, a part of the communication based train control system, mainly consists of automatic train protection(ATP) functions, automatic train operation(ATO) functions as well as the interface functions with other equipment including CBTC wayside equipment and train control management system etc. The CBTC car-borne software implementing ATP/ATO functions is a real-time embedded software requiring a high level of safety and reliability. To satisfy the requirements of the CBTC car-borne software, the model-based design techniques are applied with SCADE(Safety-Critical Application Development Environment) to the development of the CBTC car-borne software. In this paper, we illustrate the process modeling the car-borne ATP/ATO functions satisfying system requirement specification with system requirement management, modeling and document generation tools etc. supported by SCADE. In addition, the developed models corresponding to the ATP/ATO functions are applied to the train with CBTC car-borne equipment through its corresponding EN-50128 standards-compliant C code generated by the code generator. It is shown from the test result that the ATP/ATO models developed by SCADE work well while the trains are running in driverless operation mode.

• Journal of Auto-vehicle Safety Association
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• v.15 no.1
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• pp.16-26
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• 2023

Recently, the importance of simulation in a virtual driving environment as well as real road-based tests for autonomous vehicle testing is increasing. Real road tests are being actively conducted at K-City, an autonomous driving test bed located at the Korea Automobile Safety Test & Research Institute of the Transportation Safety Authority. In addition, the need to advance the K-City virtual driving environment and build a virtual environment similar to the autonomous driving system test environment in real road tests is increasing. In this study, for K-City of Korea Automobile Safety Test & Research Institute, using detailed drawings and actual field data, K-City virtual driving environment was advanced, and similarity verification was verified through comparative analysis with actual K-City.

• Smart Structures and Systems
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• v.32 no.5
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• pp.297-308
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• 2023

Dynamic deflection is important for evaluating the performance of a long-span cable-stayed bridge, and its continuous measurement is still cumbersome. This study proposes a dynamic deflection monitoring method for cable-stayed bridge based on Bi-directional Long Short-term Memory (BiLSTM) neural network taking advantages of the characteristics of spatial variation of cable acceleration response (CAR) and main girder deflection response (MGDR). Firstly, the relationship between the spatial and temporal variation of the CAR and the MGDR is described based on the geometric deformation of the bridge. Then a data-driven relational model based on BiLSTM neural network is established using CAR and MGDR data, and it is further used to monitor the MGDR via measuring the CAR. Finally, numerical simulations and field test are conducted to verify the proposed method. The root mean squared error (RMSE) of the numerical simulations are less than 4 while the RMSE of the field test is 1.5782, which indicate that it provides a cost-effective and convenient method for real-time deflection monitoring of cable-stayed bridges.

• Journal of the Korea Safety Management & Science
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• v.15 no.2
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• pp.63-69
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• 2013

The purposes of this study are to survey stereotypes of control-display relationships for seven principal controls in passenger cars using the paper-pencil and hardware tests, and to examine stereotype strength of the paper-pencil test through comparing the stereotypes for the controls derived by the two methods. Ninety two and 60 college-aged students participated in the paper-pencil test and the real car simulation of the hardware test, respectively. There are dominant motion-directions for all controls in the paper-pencil test, while in the hardware test, there are dominant motion-directions for six controls including head light, high beam, door window, ignition key, door key and door lock controls. The stereotypes of motion-directions for six controls obtained by the paper-pencil test were the same as or similar to those by the hardware test. It was inferred from this that the congruence of the stereotypes by the two methods might be attributed to two simple motion-direction principles of 'clockwise for increase' and 'upward for increase.' Although it is known that the hardware test would be best for obtaining accurate stereotypes between controls and displays, this study implies that if the paper-pencil test is well designed, the paper-pencil test can produce the same results as the hardware test at low cost and without consuming time.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.260-263
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• 2005

Fatigue fracture behavior of a hybrid joint between side-panel and under-frame by riveting and adhesive bonding has been evaluated. Two kinds of joint specimens based on real geometry were fabricated for shearing test as well as bending test. Static and cyclic loadings were used for fatigue assessment. Fatigue fracture results obtained by such experiments were reflected in modifications of design parameters of the hybrid joint.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.62-69
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• 2013

This paper proposes real-time video transmission system by the car-mounted cameras based on MOST Network. Existing vehicles transmit videos by connecting the car-mounted cameras in the form of analog. However, the increase in the number of car-mounted cameras leads to development of the network to connect the cameras. In this paper, DSP is applied to process MPEG 2 encoding/decoding for real-time video transmission in a short period of time. MediaLB is employed to transfer data stream between DSP and MOST network controller. During this procedure, DSP cannot transport data stream directly from MediaLB. Therefore, FPGA is used to deliver data stream transmitting MediaLB to DSP. MediaLB is designed to streamline hardware/software application development for MOST Network and to support all MOST Network data transportation methods. As seen in this paper, the test results verify that real-time video transmission using proposed system operates in a normal matter.

• Fire Science and Engineering
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• v.16 no.3
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• pp.71-76
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• 2002

The real scale tunnel fire tests are carried out for the first time in domestic range to assess the extent of risk in the tunnel fire. The tunnel dimension is 465 m in length, 9.2 m in width and 6.5 m in height. Gasoline pools with 0.25 MW∼2.5 MW size and a 1500CC passenger car are used as fire sources. Six jet fans are used to change the flow velocity inside the tunnel. Temperatures at total 86 points in the tunnel are measured to find the temperature distribution and smoke behavior in the real tunnel fire. In the experiment, it is examined that the important parameters to assess the extent of risk in tunnel fire such as back layering of smoke front, descending of smoke layer and the fire size of a real passenger car.