• Title/Summary/Keyword: Brake force

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Analytical Model Development of Longitudinal Railway Vehicle (철도차량의 종방향 통합해석모델 검토 및 개발)

  • Kwak Jae-Ho;Choi Kyung-Jin;Shin Yu-Jeong
    • 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.

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Optimal Design of Permanent Magnet Arrays for Eddy Current Brakes (와전류 브레이크를 위한 영구자석 배열의 최적설계)

  • Choi, Jae-Seok;Yoo, Jeong-Hoon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.609-611
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    • 2008
  • Eddy current is usually generated in material with high conductivity by time-varying source such as AC current and also is induced in the moving source with relative velocity. The contactless magnetic brakes make use of the braking force from the eddy current generated by 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 a permanent magnet type eddy current brake system to maximize the braking force. The analysis of the brake system is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method for the sensitivity analysis.

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Vehicle Stability Control for a 4WD HEV using Regenerative Braking and Electronic Brake force Distribution (회생제동과 EBD를 이용한 4WD HEV의 차량 안정성 제어)

  • Kim Donghyun;Kim Hyunsoo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.166-173
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    • 2005
  • A vehicle stability control logic for 4WD hybrid electric vehicle is proposed using the regenerative braking of the rear motor and electronic brake force distribution module. Performance of the stability control logic is evaluated for J-turn and single lane change. It is found from the simulation results that the regenerative braking at rear motor is able to provide improved stability compared with the vehicle performance without my stability control. Additional improvement can be achieved by applying the regenerative braking plus electronic brake farce distribution control. It is expected that the regenerative braking offers additional improvement of the fuel economy as well as the vehicle stability control.

Braking Characteristic of the Eddy-Current Brake with Permanent Magnet Considering Structure Around (위치변화에 따른 영구자석을 이용한 와전류 제동기의 제동특성)

  • Ha, K.H.;Kim, Y.K.;Hong, J.P.;Kim, G.T.;Kang, D.H.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.305-307
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    • 1999
  • This paper describes the braking performances considering the structures around for the eddy-current brake excited by permanent magnet. As the magnet is excited by permanent magnet, the braking force of this system interferes with the progress of a moving train in normal time. Therefore, it is necessary to determine the reasonable position of eddy current brake from rail. In this paper, the braking force according to the distance from the rail is analyzed by using 2-dimensional finite element method considering the surrounding structure of train.

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Fuzzy Model-Based Fault Detection Method of EPB System for Varying Temperature (온도변화에 강인한 EPB 시스템의 퍼지모델 기반 고장검출 방법)

  • Moon, Byoung-Joon;Kim, Dong-Han;Park, Chong-Kug
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.10
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    • pp.1009-1013
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    • 2009
  • In this paper, a robust fault detection method for varying temperature based on fuzzy model is proposed. To develop a robust force estimation model, it needs temperature information because the output of force sensor is affected by a temperature variation. The nonlinear dynamic system, such as the parking force of the EPB (Electronic Parking Brake) system is necessary to have a higher order equation model. But, because of the calculation time, the higher order equation model is hard to be used in real application. In case of the lower order equation model, the result is not as accurate as acceptable. To solve this problem, the robust fuzzy model-based fault detection is developed. A proposed fault detection method for varying temperature is verified by HILS (hardware in the loop simulation).

Development of an Aircraft Hydraulic Brake Assembly with a Self-gap-adjuster (자동 간극 조절기를 갖는 항공기용 유압식 브레이크 조립체 개발)

  • Yi, Miseon;Song, Won-Jong;Kwon, Jun-Yong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.5
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    • pp.444-451
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    • 2020
  • This study was conducted to develop the hydraulic brake assembly for MUAV(Medium-altitude Unmanned Aerial Vehicle). The brake assembly has the self-gap adjuster which performs to maintain a constant gap between the piston and the disk, even if the friction pad wore down. The function of adjuster helps to keep the brake-reaction speed constant and prevent the unnecessary abrasion of the wear pad during the life of the brake assembly. The development of the aircraft hydraulic brake assembly with the self-gap-adjuster in this paper is the first ever in South Korea. The concept of the mechanism was defined and the formula which is necessary to calculate the friction force was set up in the paper. The tester was invented for the functional test and the proper operation of the self-gap-adjuster was confirmed through the test. Dynamo tests and flight tests were also carried out to verify the braking performance of the brake assembly.

A Evaluation of Emergency Braking Performance for Electro Mechanical Brake using Interior Permanent Magnet Synchronous Motor (매입형 영구자석 동기전동기를 적용한 전기기계식 제동장치의 비상제동 성능평가)

  • Baek, Seung-Koo;Oh, Hyuck-Keun;Park, Joon-Hyuk;Kim, Seog-Won;Kim, Sang-soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.170-177
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    • 2020
  • This study examined the clamping force control method and the braking performance test results of an electromechanical brake (EMB) using braking test equipment. Most of the studies related to EMBs have been carried out in the automotive field, dealing mainly with the static test results for various control methods. On the other hand, this study performed a dynamic performance evaluation. The three-phase interior permanent magnet synchronous motor (IPMSM) was applied to drive the actuator of the EMB, and the analysis was verified by JMAG(Ver. 18.0), which is finite element method (FEM) software. The current control, speed control, and position control were used for clamping force control of the EMB, and the maximum torque per ampere (MTPA) control was applied to the current controller for efficient control. The EMB's emergency braking deceleration performance was tested in the same way as conventional pneumatic brake systems when the wheel of a train rotates at 110 km/h, 230 km/h, and 300 km/h. The emergency braking time, with the wheel stopped completely at the maximum rotational speed, was approximately 73 seconds. The similarity of the braking time and deceleration pattern was verified through a comparison with the performance test results of the pneumatic brake system applied to the next generation high-speed railway vehicle (HEMU-430X).

Analysis of the Friction Characteristics of Parking Brake for Large Size Excavator (대형 굴삭기용 주차 브레이크의 마찰 특성 분석)

  • Lee, Y.B.;Kim, K.M.
    • Journal of Power System Engineering
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    • v.16 no.2
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    • pp.5-10
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    • 2012
  • The parking brake is one of the essential units embedded in track driving motor for forward and backward motion of an excavator. It is composed of multi-friction discs. When the hydraulic motor stops, the multi-friction discs closely stick to the facing discs by acting of multi-spring forces. So, the friction forces generate the braking force by compressing the cylinder barrel of hydraulic motor. In this study, we combined the multi-friction discs to two kinds of spring which have different spring force, and the maximum torque measured at the rotational starting point of hydraulic motor through gradually increasing the rotational torque of load side hydraulic motor by use of 1 and 2 sheets of friction plates. And, under this experimental condition, the maximum coefficient of static friction and the characteristics of paper friction sheet were analyzed. The obtained experimental results will be applied to the design of parking brake system for producing large size excavator in the 85-ton weight class.

Transient Heat Transfer Analysis of Brake Drum Shape (브레이크 드럼의 형상에 따른 과도 열전달 해석)

  • Kim, Yang-Sul;An, Su-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.8
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    • pp.65-71
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    • 2008
  • This paper presents a transient heat transfer analysis of a drum brake shape. The transient heat transfer analysis of automotive drum brakes with frictional contact is performed by using the finite element method. The drum brake type studied in the page is the internally expanding one in which two shoes fitted externally with frictional material are forced outward against surface a rotating drum on the wheel unit. In this case, the braking power is produced by the friction force between a drum and a lining, and is converted into heat. The brake drum has constant material properties. The air inside the drum has temperature-dependent thermal conductivity and enthalpy. Radiation effects are ignored. The result explains the reason why hair crack and cause of drum failure occur. The temperature of drum is in proportion to the drum thickness and nonlinear changes at every points of drum. It's necessary for the decrease of the drum temperature to make the air inside drum flow.

Thermal Stress Analysis for a Ventilated Disk Brake of Railway Vehicles (철도 차량용 제동디스크의 열응력 해석)

  • Lee Y.M.;Park J.S.;Seok C.S.;Lee C.W.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1617-1621
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    • 2005
  • In this study, as a basic research to improve braking efficiency of a ventilated disk brake, we carried out a thermal stress analysis. From analysis result, we knew that a maximum mechanical stress by braking pressure and friction force is applicable to 5 percent of yield strength and has no effect on a fatigue life's decrease for brake disk material. While, a maximum thermal stress by frictonal heat is applicable to 43 percent of yield strength and locates on a friction surface. So, we have found that a thermal stress is the primary factor of crack initiation on a friction surface of disk brake

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