• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.581-588
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• 2020

This study examined a brake pad wear compensation method for an Electro-Mechanical Brake (EMB) using the braking test device. A three-phase Interior Permanent Magnet Synchronous Motor (IPMSM) was applied to drive the actuator of an EMB. Current control, speed control, and position control were used to control the clamping force of the EMB. The wear compensation method was performed using a software algorithm that updates the motor model equation by comparing the motor output torque current with a reference current. In addition, a simple first-order motor model equation was applied to estimate the output clamping force. The operation time to the maximum clamping force increased within 0.1 seconds compared to the brake pad in its initial condition. The experiment verified that the reference operating time was within 0.5 seconds, and the maximum value of the clamping force was satisfied under the wear condition. The wear compensation method based on the software algorithm in this paper can be performed in the pre-departure test of rolling stock.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.2
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• pp.77-83
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• 2000

This paper deals with the design of a touch free eddy-current brake for high speed transportation systems by using 2-dimensional Finite Element Method (2-D FEM). The eddy current brake systems have to equipped with maximum braking force and deceleration at the given volume or mass, high braking force at small rate, attraction forces as small as possible and stable construction. The parameters, such as the number of pole, electric ampere-turns and slot width have influence on these braking characteristics. For the magnet to satisfy above-mentioned performance in high speed, the braking performance according to variation of the parameters are analyzed by the 2-D FEM. In addition, the magnet stack width is determined from equivalent stack width that is calculated by solution of the Field with scalar potential. From these results, the magnet of optimized configuration with maximum braking force and minimum attraction force is designed by the process of detail design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1809-1812
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• 2013

The bogie of monorail vehicles applies rubber wheel system not steel wheel system. In addition, The structure of the bogie is very complicated because vehicle operates on the elevated road and vehicle drives with wrapping the guide way. When the monorail vehicle applies air brake system, lower device of vehicle may be complex and some devices may be limited. On the other hand, hydraulic brake equipment is compact and not weighing. Braking force is also outstanding compared with air brake so the hydraulic brake equipment is suitable for monorail vehicle. Also urban transit system such as monorail, applies mixed system both friction brake and electric brake in order to save electric energy. But application case of hydraulic brake in the country is very rare because hydraulic brake have difficulty in satisfaction of control requirement and maintenance. Therefore, this study suggests ways to design hydraulic brake system with blending brake for monorail vehicle and applies the ways to future monorail.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.707-710
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• 2001

Brakes are one of the important safety parts in cars. The requirements of brakes in performance, in comfort, and working lifetime are high. This paper presents the static analysis on the stress and temperature of a automotive drum brake. The particular interest is the distribution of the contact pressure between brake lining and drum. The problems to be solved are the effects of friction coefficient, actuation force, temperature, and brake component's stiffness. The contact problem includes friction, and is solved using the ABAQUS.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.211-217
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• 2007

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS (Anti-lock Brake System) systems. In realizing the wheel slip control systems, real-time information such as the tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance and stability enhancement. In this paper, a robust wheel slip controller is developed based on the adaptive sliding mode control method and an optimal target slip assignment algorithm is proposed for maximizing the braking force. An adaptive law is formulated to estimate the braking force in real-time. The wheel slip controller is designed based on the Lyapunov stability theory considering the error bounds in estimating the braking force and the brake disk-pad friction coefficient. The target slip assignment algorithm searches for the optimal target slip value based on the estimated braking force. The performance of the proposed wheel slip control system is verified in HILS (Hardware-In-the-Loop Simulator) experiments and demonstrates the effectiveness of the wheel slip control in various road conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.319-324
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• 2006

The objective of this study is to design and analyze a dual spring type rope brake. In general, a dual rope brake system are a device for an elevator in safety. Therefore, they are very important and difficult in designing. The finite element model was developed to compute stress, strain and friction force for a dual spring type rope brake. ANSYS code was applied for this investigation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.181-185
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• 2001

This paper deals with the dynamic stability of a disc brake pad taking into account of its shear deformation and rotary inertia. A brake pad can be modeled as a beam like model subjected to distributed friction forces and having two translational springs. The study of this model is intended to provide a fundamental understanding of dynamic stability of drum brake pad. Governing equations of motion are derived from extended Hamilton's principle and their corresponding numerical solutions are obtained by applying the finite element formulation. The critical distributed friction force and the instability types are investigated bt changing two translational spring constants, rotary inertia parameter and shear deformation parameter. Also, the changes of eigen-frequencies of a beam determining instability types are investigated for various combinations of two translational spring constants.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.42-47
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• 2015

This paper studies on the design of a servo controller for an antilock brake system(ABS) based on the car tire model. First, a nonlinear differential equation of the car tire is constructed and its linearization model is obtained by Taylor's series. Second, a servo controller based on the mathematical model is analytically designed to obtain the maximum brake force, where the tire velocity and the slip ratio of car tire are respectively controlled to the given command values. Third, it is theoretically shown that the proposed control algorithm has good usefulness in ABS.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.7
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• pp.658-663
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• 2009

Eddy current is usually generated in the material with high conductivity by time-varying source such as AC current and also is induced by the moving source with relative velocity. The contactless magnetic brake makes use of the braking force from the eddy current generated by the moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of the eddy current brake system of a permanent magnet type where the design aim is to maximize the braking force. The analysis of brake systems is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method is applied for the sensitivity analysis.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.120-127
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• 1996

Anti-lock Brake System has been developed to reduce tendency for wheel lock and improve vehicle control during sudden braking on slippery road surfaces. This is achieved by controlling the braking pressure, avoiding wheel lock, while retaining handling and brake performance. This paper is concerned about pressurecharacteristics of hydraulic modulator. Experimental sets which is consists of hydraulic modulator, duty controller, pressure regulator, pressure senset is consuructed. System modelling and computer simulation are performed for comparison with experimental results. Brake wheel pressure are measured under various driving pulse. The result of experiment show fairly agreement with the simulation. As a result, it is known that wheel pressure is affected by duty ratio, orifice diameter through computer simulation.