• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4419-4441
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• 2016

A cause of vehicle accidents is the reduced visibility due to bad weather conditions such as fog. Therefore, an onboard vision system should take visibility detection into account. In this paper, we propose a simple and effective approach for measuring the visibility distance using a single camera placed onboard a moving vehicle. The proposed algorithm is controlled by a few parameters and mainly includes camera parameter estimation, region of interest (ROI) estimation and visibility computation. Thanks to the ROI extraction, the position of the inflection point may be measured in practice. Thus, combined with the estimated camera parameters, the visibility distance of the input foggy image can be computed with a single camera and just the presence of road and sky in the scene. To assess the accuracy of the proposed approach, a reference target based visibility detection method is also introduced. The comparative study and quantitative evaluation show that the proposed method can obtain good visibility detection results with relatively fast speed.

• Journal of computational fluids engineering
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• v.19 no.1
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• pp.7-14
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• 2014

Aerothermodynamic characteristics of re-entry vehicles in hypersonic speed regimes are investigated by applying CFD methods based on the Navier-Stokes-Fourier equations. A special emphasis is placed on the effects of high temperature chemically reacting gases on shock stand-off distance and thermal characteristics of the flowfields. A ten species model is used for describing the kinetic mechanism for high temperature air. In particular, the hypersonic flows around a cylinder are computed with and without chemically reacting effects. It is shown that, when the chemically reacting effects are taken into account, the shock stand-off distance and temperature are significantly reduced.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.4
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• pp.558-565
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• 2017

The vehicle-mounted mine detection system with large detection sensor modules can search wide areas with a fast detection speed. To mount the heavy mine detectors on a manned or unmanned vehicle, it is necessary to design the detector driving mechanism and control system based on the considerations driven from the characteristic analysis and the operation requirements of the detection system. Furthermore, while operating the mine detector mounted on a mobile vehicle, it is significant to keep the height from the ground to sensors within a certain distance in order to get a qualified detection performance. As the mine detection sensor, we used ground penetrating radar widely used to geotechnical exploration, mine detection and etc. In this paper, we introduce a driving mechanism through analyzing the characteristics of the vehicle-mounted mine detection system. We also suggest a method to automatically control the distance between the ground and GPR by utilizing the GPR output values, used to detect mines at the same time.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.94-99
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• 2012

Due to economic growth, the number of cars has grown rapidly and consequently traffic accidents have grown in direct ratio. This reminds us that braking device of a vehicle is an important factor to prevent traffic accidents. Aim these researches to speed and lighten the braking system of vehicles, to lengthen its durability and to shorten the stopping distance. However, it is still difficult to analyze quantitatively and clearly the reason and solution for abnormal wear of disc and pad or judder in flywheel mode. Therefore this study was carried out to presume for mutual relation of analysis condition to get the optimum temperature by two-way layout. The results shown that coefficient of determination has a fine reliability over 92.57% and temperature is made by two-way layout.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.7-13
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• 2011

The climate change due to the increased consumption with fossil fuel and rise of the oil price have been serious global issues. Automobile industry consumes 30% of the oil every year and causes air pollution and global warming by the exhaust emissions and carbon dioxide ($CO_2$). The demand of two-wheeled vehicle increases every year due to the parking and traffic problem caused by the increased automobiles in the urban area. Approximately 50,000,000 two-wheeled vehicles were produced in 2008. The development and sales of the hybrid two-wheeled vehicle industry become active due to its increased market demands. In this paper, the change of the motor and battery efficiency, driving distance, hill climbing ability with the change of the motor capacity was analyzed. Simulation of the peculiarities in urban driving schedule(World-wide Motorcycle Test Cycle(WMTC), Manhattan driving schedule), constant speed(10 km/h, 35 km/h) of small electronic two-wheeled vehicle was also carried out. Through the simulation result, appropriate capacities of the motor and battery for urban driving was acquired.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.58-61
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• 2006

The effect of the steel ratio on the behavior of continuously reinforced concrete pavement (CRCP) under moving wheel loads and environmental loads were investigated in this study. The CRCP sections having different steel ratios of 0.6, 0.7, and 0.8% were considered: (1) to evaluate the load transfer efficiency (LTE) at transverse cracks; (2) to investigate strains in CRCP when the system is subjected to moving vehicle loads; (3) and to investigate the time histories of the crack spacing variations. The LTEs were obtained by conducting the falling weight deflectometer (FWD) tests. The strains in the concrete slab and the bond braker layer under moving vehicle loads were obtained using embedded strain gages. The results of this study show that the LTEs at transverse cracks are very high and not affected by the steel ratio. The strains in CRCP under vehicle loads become smaller as the vehicle speed increases or as the wandering distance increases; however, the strains are not clearly affected by the steel ratio. However, the changes in the crack spacings are affected by the steel ratio.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.833-836
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• 2013

In this paper, we proposed an intelligent surveillance system which can be determined by the overspeed of vehicle which continuously collects by video imaging device. Imaging device to capture images continuously, and filtering errors that occur as a natural, long-distance moving objects by comparing the images collected before and after the images. To measure the size of things, it proves that able to measure speed of the vehicle, depending on the amount of growing pixels using the pixel processing.

• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.108-116
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• 2004

In this paper, the measurement system of speed and distance of vehicles using laser is implemented and verified through the outdoor test. The implemented system consists of a laser module and a control/speed-computation module. The Former is composed of a optics part, a transmit/receive part, and a LDC(Laser Detection and Counter), and the latter is a control part that controls the laser module and a speed computation part that calculates velocity of vehicles using a microcontroller. The algorithm to compute speed has been developed to consider characteristics of laser and surrounding conditions. The implemented system has been tested and verified on the high way, and the result shows stability of the system and accuracy of the algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.4
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• pp.525-533
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• 1998

A conventional contact type brake system which uses a hydraulic system has mny Problems such as time delay response due to pressure build-up, brake pad wear due to contact movement, bulky size, and low braking performance in high speed region. As vehicle speed increases, a more powerful brake system is required to ensure vehicle safety and reliability. In this work, a contactless brake system of an eddy current type is proposed to overcome problems. Optimal torque control which minimizes a braking distance is investigated with a scaled-down model of an eddy current type brake. It is possible to realize optimal torque control when a maximum friction coefficient (or desired slip ratio) corresponding to road condition is maintained. Braking force analysis for a scaled-down model is done theoretically and experimentally compensated. To accomplish optimal torque control of an eddy current type brake system, a sliding mode control technique which is, one of the robust nonlinear control technique is developed. Robustness of the sliding mode controller is verified by investigating the braking performance when friction coefficient is varied. Simulation and experimental results will be presented to show that it has superior performance compared to the conventional method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.7
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• pp.465-472
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• 2004

Analog CPPN-based optimal road boundary detection algorithm for autonomous vehicle is proposed. The CPPN is a massively connected analog parallel array processor. In the paper, the dynamic programming which is an efficient algorithm to find the optimal path is implemented with the CPPN algorithm. If the image of road-boundary information is utilized as an inter-cell distance, and goals and start lines are positioned at the top and the bottom of the image, respectively, the optimal path finding algorithm can be exploited for optimal road boundary detection. By virtue of the parallel and analog processing of the CPPN and the optimal solution of the dynamic programming, the proposed road boundary detection algorithm is expected to have very high speed and robust processing if it is implemented into circuits. The proposed road boundary algorithm is described and simulation results are reported.