• Proceedings of the KSME Conference
• /
• 2000.04a
• /
• pp.684-689
• /
• 2000

In this paper, the equations of motion about vehicle, powertrain and brake system were derived. The vehicle has eight degrees of freedom with nonlinear tire model and the powertrain has two degrees of freedom containing engine, torque converter and four speed automatic transmission. The brake system has two states about front and rear brake line pressures. The transient tire model with first order time lag is also subjoined for low speed or stop-and-go simulation. The modeling was derived considering two points - the fidelity and the simplicity. The simulation using this model is similar with real vehicle dynamic behavior and the model is made as simple as possible far fast simulation. It is validated that the derived vehicle model can be applicable to the real time simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.7
• /
• pp.653-660
• /
• 2009

A helicopter rotor brake system stops or reduces the speed of the rotor by transforming the kinetic energy into the heat energy. The frictionally generated heat has a considerable effect on the frictional property of material itself and causes the change of the friction coefficient which may affect the breaking time significantly. In this paper, to take into account the effect of change of friction coefficient according to temperature on braking time, thermo-mechanically coupled analysis is carried out by commercial software ABAQUS. Further, simple theoretical equation is derived considering thermo-mechanical behaviors. The predicted braking times both from theoretical and numerical methods are compared and validity of proposed theoretical equation is investigated.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.2080-2093
• /
• 2008

Disk brake system take charge of maximum braking energy among the mechanical brake systems for high speed train. For this reason, Metallic friction materials and heat resistant steel disk is adopted at disk brake system for high speed train. It was investigated tribological characteristics(friction coefficient, friction stability, wear rate and braking temperature) between some kinds of metallic friction materials and heat resistant steel disk. Cu-based friction material for high speed train have suitable tribological characteristics.

• Journal of Advanced Navigation Technology
• /
• v.27 no.5
• /
• pp.621-628
• /
• 2023

This study derived a reverse engineering procedure for verifying the design identity of original parts and developed parts for PMA(Parts Manufacturer Approval) and STC(Supplemental Type Certificate) of metal brake pads for transport aircraft, which are critical parts among aircraft parts and equipment. In Korea, the regulations for reverse engineering procedures are regulated by the Parts Manufacturer Approval Guidelines, and in the United States, AC No. 21. 303-4. In the reverse engineering for the brake pad, the detailed procedures for each component were determined by selecting verification test items to confirm identity based on sample quantity, dimensional tolerance, mechanical property measurement, material, weight and volume characteristics for each component. In addition, as a result of analyzing the regulation of Korea and United States, in the case of Korea, it is necessary to establish technical standards for braking systems for transport aircraft and regulations related to flight tests.

• Journal of Advanced Navigation Technology
• /
• v.27 no.6
• /
• pp.821-827
• /
• 2023

In this study, the aircraft technical standards of the Korea and the United States were analyzed to derive the dynamometer test procedure required to prove the compatibility for flight test certification of the metal brake pad for transport aircraft. Since the design modification of the brake systems is classified as a major change, the STC(Supplemental Type Certificate) and the PMA(Parts Manufacturer Approval) are required. In accordance with the TSO-C135a, the technical standard order for brake system in the United States, the design landing-stop test, accelerate-stop test, and most severe landing stop test were selected among the test items for flight test. The conditions for the dynamometer test are determined according to the specifications provided by aircraft manufacturer, and the brake pad condition, deceleration, and the number of test are defined according to the TSO-C135a.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.4 no.4
• /
• pp.117-123
• /
• 2000

열차와 교량의 3차원 모델링을 사용한 고속철도 교량의 동적해석이 수행되었다. 철도교의 모델인은 판요소와 3차원 뼈대요소로 모델링되었다. 상판과 주형 사이의 offset은 기하학적인 구속조건을 사용하여 고려하였다. 본 연구에서 사용된 고속철도는 2량의 동력차와 2량의 모터차와 16량의 객차로 구성되어 있다. 관절형 대차로 연결되어 전체 열차계의 운동방정식은 Lagrange 방정식을 이용하여 유도되었으며, 차제와 대차 그리고 자축의 3차원인 운동을 고려하였다. 이동 열차에 의한 교량의 응답은 predictor-corrector 반복법에 의한 Newmark-$\beta$ 법에 의해서 그 해가 구해진다. 매개변수해석에 의해서 열차의 이상화방법, 열차의 제동, 철도교량의 주행면 조도에 의한 영향이 고찰되었다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.4
• /
• pp.578-585
• /
• 2018

This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.40 no.8
• /
• pp.485-494
• /
• 2016

In this work, we conducted a study of fuel consumption characteristics and regenerative braking recovery rate by conducting an experiment using a TMED type parallel hybrid electric vehicle. As regenerative braking technology is considered essential to improve the energy efficiency of the hybrid vehicle, it is necessary to conduct research on the regenerative braking system. Therefore, the electrical characteristics, current balance, and fuel consumption were investigated using an EC type chassis dynamometer with experimental conditions as per IM240 mode. From the results, it was observed that when the initial SOC condition was lower, the engine operating time of the hybrid vehicle increased, and the energy efficiency decreased. While operating in the driving mode characteristics condition and the driving characteristics condition, the difference in the average fuel consumption was not significant. However, after completion of the experiment, there was a difference in the engine operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.11
• /
• pp.981-988
• /
• 2016

Dynamometer is a device for testing the performance of the brake and it is composed of a test zone, the mechanical inertia zone, the electric motor and the control zone. Hybrid dynamometer is a way to compensate for the loss of mechanical inertia in accordance with the brake operation by using an electric motor to reduce the size of the mechanical inertia with the advantage that can be tested in the relatively small size of the mechanical inertia and low cost. In this paper, design the proper size of hybrid dynamometer in the laboratory level with the space constraints, analysed the effect of critical parameter on the braking performance of hybrid dynamometer such as changing the friction coefficient. With this study, could get the results of guideline to judge the poor friction material by measuring the torque of the electric motor to compensate the energy loss due to a reduced mechanical inertia.

• Journal of the KSME
• /
• v.32 no.11
• /
• pp.910-916
• /
• 1992

신엔진 개발에서 동력을 증대시키려는 연구와 얻어진 에너지가 엔진을 구동시키기 위한 내부에 너지로 소비되지 않고 가능한 제동마력으로 보내려는 에너지 절약의 측면에서 접근하려는 연구가 있다. 전자의 연구개발은 연료와 공기의 열유동 해석, 혼합비 조절, 점화시기 및 방법, 연료의 선정, 터보차저의 설치, 즉 엔진에 공급되는 고열원부의 열량 $Q_H$ 를 증가 시키든지 또는 대기중으로 방출하는 저열원부의 열량$Q_L$ 을 어떻게 감소시키느냐에 관심을 가지고 있는 연구이다. 그러나 후자의 경우는 이미 생산된 에너지를 가능한 한 소비시키지 않고 모두 제동 마력으로 보내도록 노력하는 연구, 즉 트라이몰로지에 기초를 둔 연구개발 분야이다. 엔진개발 에서 트라이볼로지의 역할은 대단히 중요하나 기술 자체가 대단히 미시적이기 때문에 신기술 개발이 대단히 어려우며, 이 분야의 필요성이 크게 대두된 것도 십수년 전에 불과하므로 기술 축적이 많이 안된 분야 중의 하나이다. 트라이볼로지 기술의 필요성이 현저하게 부각되기는 하 였지만 해결하기가 대단히 어려운 분야이다. 그러나 일단 섬세하고도 미시적인 트라이볼로지 기술의 벽을 극복하면 큰 효과를 발휘하게 된다. 고도의 첨단기술을 개발하고 적용해야 하는 선진기술국에서는 에너지 절약의 측면보다는 새로운 기술개발의 측면에서 트라이볼로지 기술을 적극적으로 지원하고 있다.