• Proceedings of the KSR Conference
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• 2007.11a
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• pp.78-81
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• 2007

In this study, brake shoe applied railway vehicle in korea is investigated and estimated a point of view effecting on wheel wear and brake performance, vehicle performance. The property and shape of brake shoe on domestic and foreign vehicle is compared and estimated and brake shoe applied railway vehicle in korea is recommended.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.491-491
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• 2000

In this paper, we report the results about the rotational control count on DC motor to drive the mobile vehicle as a first step of the research for the realization of the mobile vehicle with the artificial brain. First of all, we introduce the configuration of the mobile vehicle. This mobile vehicle has one CCD camera driven by a rear wheel. Secondly we show the control methods. This research is adopted the various controls. Finally we report the experimental methods and results and we describe the conclusion of this research.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.986-993
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• 2011

The role of brake is safely to transport passenger & cargo and stop vehicles at emergency in railway vehicle. Brake system reduces the speed by control command of electricity or air. mechanical methods to perform brake are disk brake & tread brake. This study targeted development of highly efficient sintered alloy brake shoe in railway vehicle whose high frictional coefficient, wear resistance, compatibility of the existing tread brake shoe & minimization of wheel's thermal damage and performed development of friction material's formulation, analysis of pressure distribution in wheel tread & brake shoe, optimum form design through analysis of heat flow.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1486-1493
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• 2006

This paper presents a dynamic model of a high mobility tracked vehicle composed of rigid bodies. Track is modeled as an extensible cable and the track tension between the sprocket and roller is calculated by the catenary equation. The ground force acting on a road wheel is calculated by the Bekker's pressure-sinkage relationship using the segmented wheel model. System equations of motion and constraint acceleration equations are derived in the joint coordinate space using the velocity transformation method.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.50-55
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• 2010

In recent years, the development of fuel cell vehicles has further accelerated because of environmental problem and petroleum resources shortage. The fuel cell vehicles have the stack which converts fuel to electricity. The stack is usually mounted by bush to isolate the vibration of chassis and body. This paper analyzed the vibratory characteristics of stack and chassis, body system. The wheel forces of fuel cell vehicle are measured to estimate the road load data. And the paths of vibration from wheel to stack are analyzed by CAE. According to the test and CAE results, the improvement of stack vibration are evaluated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.383-386
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• 2005

An integrated analytical model which should have essential dynamics on the longitudinal railway vehicle is developed. The model consists of translational movement, rotational movement, brake actuator, adhesion force between rail and wheel, and brake friction force between wheel and pad. Thus, during the deceleration for stopping, a feedback controller controlling the brake cylinder pressure is designed to improve ride quality and to release friction problems. Through the developed model, the feasibility of controlling the cylinder pressure is verified for the better performances during braking.

• Interaction and multiscale mechanics
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• v.3 no.4
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• pp.333-342
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• 2010

The Pseudo-Excitation Method (PEM) is applied to study the stochastic space vibration responses of train-bridge coupling system. Each vehicle is modeled as a four-wheel mass-spring-damper system with two layers of suspension system possessing 15 degrees-of- freedom. The bridge is modeled as a spatial beam element, and the track irregularity is assumed to be a uniform random process. The motion equations of the vehicle system are established based on the d'Alembertian principle, and the motion equations of the bridge system are established based on the Hamilton variational principle. Separate iteration is applied in the solution of equations. Comparisons with the Monte Carlo simulations show the effectiveness and satisfactory accuracy of the proposed method. The PSD of the 3-span simply-supported girder bridge responses, vehicle responses and wheel/rail forces are obtained. Based on the $3{\sigma}$ rule for Gaussian stochastic processes, the maximum responses of the coupling system are suggested.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.44-51
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• 2006

This paper addresses sliding mode control of the anti-lock braking system (ABS) with a disturbance observer for model uncertainties such as vehicle parameter variation, un-modeled dynamics, and external disturbances. By using a nominal vehicle model, a sliding mode controller is designed to achieve a desired wheel slip ratio for ABS control. To compensate the model uncertainties, a disturbance observer is introduced with the help of a transfer function of a hydraulic brake dynamics. A proposed sliding mode controller with a disturbance observer is evaluated through simulations for model uncertainties. The simulation results show that the disturbance observer can enhance performances of sliding mode control for ABS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.411-412
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• 2006

It is very difficult to analyze the dynamic characteristic because railway vehicle is a very complex system which are connected various mass element with railway vehicle system. To realize and analyze actual phenomenon has restriction that usual commercial software calculates creep force under creep theory about wheel-rail contact mechanism as basic analyzing, and approach about contact point are based on two dimensional non-linear contact theory and simplified Hertzian contact which considers just displacement change on the YZ plain. Therefore, to solve these problems there should be a new approach difference with existing one. In this research, a new algorithm for finding wheel-rail contact position, calculation method of contact force and applied force will be presented.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.84-93
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• 2004

This study carries out the performance improvement and simplification of hydraulic modulator that plays an important role in vehicle stability control systems. The mathematical models for each component of a modulator, such as pump, wheel cylinder, check and solenoid valve, accumulator, damper are derived in detail. All the mathematical models are combined to form a modulator system and implemented through a computer program, which can be controlled by a user friendly GUI. To verity the simulation, comparison between simulation and experiments has been made. After the verification of the validity of the simulation, the effects of the design parameters of the modulator on the wheel cylinder pressure is investigated. The results show that the modulator without MPA has advantage in early time pressure rise rate, and it can be simplified.