• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.144-149
• /
• 2008

A transient finite element simulation is developed for the two-dimensional stationary elastoplastic layer between sliding layers, to investigate thermoelastoplastic instability(TEPI) due to frictional heating in the material. The analysis will show some differences between the case of thermoelastic instability and TEPI, especially according to the contact pressure above yield stress. A transient behavior of contact pressure is captured to explain the behavior of thermoplasticity of contact with different sliding velocity. The instability of contact pressure in the long range of braking time will be explored to understand the generation mechanism of hot spots.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.45-50
• /
• 2000

While braking cars, a large amount of energy is taken into the brake system in a short period of time. This leads to some problems ; cracking of the disc, non-uniform wear of pad and disc, fade. Thus it is important to measure the contact thermal behaviour precisely between disc and pad. The measurements must be considered to design the brake system. The paper describes methods to analysis the problem of the thermal behavior on the ventilated disc with ANSYS-a program of FEA and a brake dynamometer. According to this way, the paper can present the error between the data by the dynamometer and the results of analysis by ANSYS.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.25 no.2
• /
• pp.219-226
• /
• 2017

This paper addresses the effective and quantitative image DB construction for the development of front looking camera systems. The automotive industry has expanded the capability of front camera solutions that will help ADAS(Advanced Driver Assistance System) applications targeting Euro NCAP function requirements. These safety functions include AEB(Autonomous Emergency Braking), TSR(Traffic Signal Recognition), LDW(Lane Departure Warning) and FCW(Forward Collision Warning). In order to guarantee real road safety performance, the driving image DB logged under various real road conditions should be used to train core object classifiers and verify the function performance of the camera system. However, the driving image DB would entail an invalid and time consuming task without proper guidelines. The standard working procedures and design factors required for each step to build an effective image DB for reliable automotive front looking camera systems are proposed.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.270-277
• /
• 2009

This paper describes the method of how to improve the probability of the tracing stopping ratio which is the most important factor in Automatic Train Operation (ATO). Aspects of improving the performance of automatic driving, the followings are investigated and studied : the interface between the signal system and the vehicle, the need to improve braking system, test method of blending brakes, how to minimize the delay of commands for real-time control. In this study, we applied this method to prove the effectiveness in DAEJEON LINE1

• Proceedings of the KSR Conference
• /
• 1999.05a
• /
• pp.251-258
• /
• 1999

This paper is mainly concerned with the development of the ATO(Automatic Train Operation) profile on precision stop controller. The ATO system is used for automatic or driverless operation of a train. In this paper, the algorithm for ATO controller is presented and three speed profiles on precision stop controller are compared. One profile is based on the maximum jerk control, another on the constant control input, and the third on the optimal control for the minimum energy consumption. These profiles are simulated and analyzed in view of the stop time, control input, jerk, propulsion and braking.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.330-332
• /
• 1997

In this paper, a development of the 7.2kV class $SF_6$ gas electromagnetic contactor which is used a rotary-arc principle in interrupting method is presented. A prototype contactor is made. In the interrupting small current permanent-magnet is used and in the interrupting high current the coil through which arc current itself flows is used. Successfully the prototype contactor carrys out the making, the braking and short time test.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1454-1456
• /
• 2000

This paper describes the method to develop the ATO software system. The software design is based on VxWorks, a Real Time Operating System. ATO calculates tractive effort/braking effort to keep the train at a certain speed reference at each moment. The speed reference is calculated by the ATO from a number of external factors. The ATO with this software is installed standardized EMU. and tested In Seoul Line 7.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2000.11a
• /
• pp.141-146
• /
• 2000

It has many variables and factors to design the friction materials for automotive brake pads. In this study, the friction and wear characteristics of automotive blake pads have been studied using 1:l full size dynamo meter. Using conventional manners, it takes a great of time and efforts to know that it affects the each raw materials for friction characteristics. For the purpose of examining the effect of each major raw materials, we used the more convenient Taguchi L9 ($3^4$) orthogonal matrix and 1/5 scale dynamo machine for evaluation of the friction characteristics of composite brake pads.

• Proceedings of the KSR Conference
• /
• 2002.05a
• /
• pp.431-436
• /
• 2002

Train driving should be satisfied to run fixed distance within given time, and it is desirable to minimize energy consumption. Minimizing energy consumption depends on the train operation modes by driver or automatic operation. In this article, an optimal operation to minimize energy consumption by changing modes of train operation by a driver is investigated. First, powering model, braking model and consumed energy calculation model are introduced by using Matlab software. The accuracy of the model established by simulation is compared with the real experimental data, which is obtained from an authorized institution. Second, several simulations under a variety of operations in the ideal track are executed, and then the optimal pattern of train driving is found.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.10
• /
• pp.505-510
• /
• 2006

This paper deals with skew and overhang effects of permanent magnet linear synchronous motor(PMLSM). The detent force and thrust characteristics considering skew and overhang effects of permanent magnet are analyzed by 3D finite element method and the results are compared to experimental values. As skew and overhang are applied to permanent magnet, the thrust is almost the same value but the detent force is reduced remarkably. By harmonic analysis, the distortion ratio of thrust is remarkably reduced from 4.29[%] to 2.3[%]. and, the ripple ratio of thrust is decreased from 8.2[%] to 3.56[%] at the same time. But, the lateral force which operate as the perpendicular direction of skew direction is generated. The lateral force and normal force acts by braking force between mover and LM-guide.