• Journal of Auto-vehicle Safety Association
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• v.8 no.4
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• pp.31-37
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• 2016

Since real road experiments have many restrictions, a multi-vehicle traffic simulator can be an effective tool to develop and evaluate fully automated driving systems. This paper presents multi-vehicle environment simulation tool to develop and evaluate motorway automated driving systems. The proposed simulation tool consists of following two main parts: surrounding vehicle model and environment sensor model. The surrounding vehicle model is designed to quickly generate rational complex traffic situations of motorway. The environment sensor model depicts uncertainty of environment sensor. As a result, various traffic situations with uncertainty of environment sensor can be proposed by the multi-vehicle environment simulation tool. An application to automated driving system has been conducted. A lane changing algorithm is evaluated by performance indexes from the multi-vehicle environment simulation tool.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.67-71
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• 2014

Based on the analysis of the actual passenger vehicle fire cases for recent four years (2010~2013), the passenger vehicle fire is increasing annually. Main root cause was analyzed as an electric problem as a 39%. Vehicle fire case by electric problem was mainly caused by use of Non-genuine part. Vehicle fire case by mechanical problem was mainly caused by various oil system maintenance. Vehicle fire case by smoking material was mainly caused by cigarette and disposal lighter. And external fire transition issue and towing mistake fire cases was also confirmed.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.257-257
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• 2000

The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A predictive control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in forward and backward direction in such a way to satisfy the given constraint condition, maintain consistency, reduce the uncertainties, and guarantee robustness. A series of experiments was conducted to evaluate the control performance, in which a car Like robot was utilized to quit unwanted safety problem. As the results, the robot was keeping very well a given lane with arbitrary shape at moderate speed.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.9
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• pp.51-58
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• 2002

Vehicle dynamics control systems are. complex and non-linear, so they have difficulties in developing a controller for the anti-lock braking systems and the auto-traction systems. Currently the fuzzy-logic technique to estimate the absolute vehicle speed is good results in normal conditions. But the estimation error in severe braking is discontented. In this paper, we estimate the absolute vehicle speed by using the wheel speed data from standard 50-tooth anti-lock braking system wheel speed sensors. Radial symmetric basis function of the neural network model is proposed to implement and estimate the absolute vehicle speed, and principal component analysis on input data is used. Ten algorithms are verified experimentally to estimate the absolute vehicle speed and one of those is perfectly shown to estimate the vehicle speed with a 4% error during a braking maneuver.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.106-116
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• 1997

In this paper, using MATLAB SIMULINK, a generalized design methodology was suggested for multi pass transmission(MPT) by classifying the vehicle power train as prime mover, MPT and vehicle dynamics. This approach enables a designer to investigate the influence of each transmission component by simple combination of system components without changes of overall program. Using the design methodology, a MPT consisting of CVT, 2, clutches and reduction gears was designed for a braking energy regenerative flywheel hybrid vehicle. The CVT is essential in order to connect the engine and flywheel speed with the vehicle speed. For the purpose of smooth clutch operation, control algorithm was suggested by introducing dead zone for the clutch engagement. Using the SIMULINK model, performance of the flywheel hybrid vehicle with MPT was investigated. It was observed from the simulation results that the MPT vehicle showed better fuel economy, 47% than that of AT vehicle, 27% than that of CVT vehicle for ECE-15 driving cycle. Especially destinct fuel efficiency improvement was obtained for city driving cycle requiring more frequent stop and start.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.190-197
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• 2000

A graphic vehicle modeling pre-processing program and a visualization post-processing program have been developed for AutoDyn7, which is a special program for vehicle dynamics. The Rapid-App for GUI(Graphic User Interface) builder and the Open Inventor for 3D graphic library have been employed to develop these programs in Silicon Graphics workstation. A Graphic User Interface program integrates vehicle modeling pre-processor, AutoDyn7 analysis processor, and visualization post-processor. In vehicle modeling pre-processor, vehicle hard point data for a suspension model are automatically converted into multibody vehicle system data. An interactive graphics capabilities provides suspension modeling aides to verify user input data interactively. In visualization post-processor, vehicle virtual test simulation results are animated with virtual testing environments.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• Journal of the Korean Society for Railway
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• v.10 no.4
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• pp.431-437
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• 2007

This paper describes the dynamic modeling of a railway vehicle when it is under braking force. It is important for the enhancement of braking performance to establish a proper dynamic model of a railway vehicle because the braking performance is affected by some dynamic forces generated by a railway vehicle when it undergoes braking. In this paper, a dynamic model for one vehicle is suggested to compute the dynamic behavior of a railway vehicle in the HILS(Hardware In-the-loop Simulation) system for the railway vehicle braking devices. To simplify the dynamic model, friction between a wheel and a rail is assumed that there exist only the static and the dynamic friction forces. Static friction coefficient is also assumed to be a function of the running speed. Some simulations are carried out with various braking forces, and the braking characteristics according to the change of the braking force are discussed. This study can provide some fundamental results to construct the HILS system for braking devices of a railway vehicle.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.487-489
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• 1998

To evaluate vehicle performances and driving behavior of a vehicle, it is necessary to acquisit and analyze vehicle data during the vehicle driving, which affect fuel economy and emissions. An in-vehicle data acquisition system, which is called Mode Survey System(MOSS), is designed and developed to analyze the traffic and driving patterns of the vehicle. MOSS is a stand-alone system based on the 68HC11 MCU. MOSS logs various data relating to powertrain and vehicle driving such as vehicle speed, engine RPM, gear position, brake, clutch, fuel consumption, and others. The driving patterns are dependent on the driver's habit and the road and traffic conditions, these driving patterns would be able to make a official driving mode to be used in emission, fuel efficiency, shift survey, catalyst durability, and other tests using the analyzed driving patterns.

• Smart Structures and Systems
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• v.13 no.5
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• pp.821-848
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• 2014

This paper presents a novel method to carry out monitoring of transport infrastructure such as pavements and bridges through the analysis of vehicle accelerations. An algorithm is developed for the identification of dynamic vehicle-bridge interaction forces using the vehicle response. Moving force identification theory is applied to a vehicle model in order to identify these dynamic forces between the vehicle and the road and/or bridge. A coupled half-car vehicle-bridge interaction model is used in theoretical simulations to test the effectiveness of the approach in identifying the forces. The potential of the method to identify the global bending stiffness of the bridge and to predict the pavement roughness is presented. The method is tested for a range of bridge spans using theoretical simulations and the influences of road roughness and signal noise on the accuracy of the results are investigated.