• Proceedings of the Korean Society of Rheology Conference
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• 2000.05a
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• pp.100-103
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• 2000

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2320-2322
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• 2004

전자제어식 미끄럼방지 제동장치 (ABS, Antilock Brake System)는 차량의 급제동시 발생할 수 있는 바퀴의 슬립을 방지하여 차량의 제동거리를 단축시키고 주행 성능을 향상시키는 차량 내 안전장치이다. 지난 몇 년 동안 공압식 제동시스템을 사용하는 대형차량에 적합한 미끄럼방지 제동 제어기를 연구해 왔다. 이 제어기는 바퀴의 슬립율과 그 변화량을 이용한 제어 법칙을 유도하여, 제어 파라미터로 사용하고 있다. 이러한 제어 파라미터의 튜닝에는 맡은 반복적인 실험이 요구된다. 이러한 요구에 부응하기 위하여 차량의 제동을 실시간으로 모사 할 수 있는 HILS (Hardware In-the Loop Simulation) 시스템을 개발, 구축하였다. 개발 HILS는 공압식 브레이크 시스템 및 14 자유도를 가지는 차량 동역학 모델 및 타이어-바퀴 동역학을 소프트웨어 모델로 사용하고, 개발 중인 전자제어식 미끄럼 방지 제동 제어기를 하드웨어로 사용하여, 바퀴속도 센서 신호 모의 장치 및 공압 엑추에이터 모의 신호등의 인터페이스 장치를 사용하여 제동중인 차량의 상태를 실시간으로 시뮬레이션 및 감시할 수 있다. 이 개발 HILS를 이용하여 제동 제어기의 제어 파라미터의 튜닝을 짧은 시간에 성공적으로 끝낼 수 있었을 뿐만 아니라, HILS 실험을 마친 제어기는 미끄럼 방지 제동 시험장에서 실차 주행 시험을 무사히 마침으로써, 개발 기간과 비용을 절감할 수 있는 하드웨어를 이용하는 시뮬레이션의 효용성을 간접적으로 증명하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4469-4474
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• 2014

This paper proposes a novel analysis method on the driving performance of LIM (linear induction motor) by FEM (finite element method). First, a linear model was converted with a rotation model to perform the dynamic analysis for a long time. Through the FEM model, the slip parameter for the control algorithm could be induced effectively. The LIM for the traction system was performed at a constant V/f in the region of constant torque, and a constant V and variable f in the region of constant power. Several slip characteristic curves according to the voltage and frequency were calculated by FEM in advance. The driving performance was then induced by interpolating the slip characteristic curves according to the load of the vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.174-180
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• 2006

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 braking control systems. In order to achieve the superior braking performance through the wheel slip control, 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, stability enhancement, etc. In this paper, a wheel slip control system is developed for maintaining the vehicle stability based on the braking monitor, wheel slip controller and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw moment controller and fuzzy logic. The performance of the proposed wheel slip control system is verified in simulations and demonstrates the effectiveness of the wheel slip control in various road conditions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.3
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• pp.29-37
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• 2000

In this paper, the thrust control of PWM Inverter-fed SLIM(Single-sided Linear Induction Motor) is achieved by vector control and PID control with DSP(TMS320C32). SLIM which used as a conveyor has required the quick response and the constant operating without air gap trembling while it conveys load.Thus, SLIM should have the smallest trembling of air gap length. First, voltage equations for SLIM are calculated from the proposed equivalent circuit in this peper, and not only the exciting current but also the thrust component are obtained from them. The thrust current ripple can be reduced by the vector controller using a slip angle frequency, and the PID controller is also use for the position control.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.811-823
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• 2019

Slip form method is applied to many cases of a shaft these days because it is safer, more economical and faster than cast-in-place method. Slip-up height of the method is approximately 2.5 to 4.0 m/day. If the temperature of concrete is outside the range of 10 to 30℃, the effects of changes in strength or elastic characteristics are significant. Therefore, it is difficult for slip-up speed to be higher than 3 m/day during winter construction. In addition, concrete has heat caused by hydration, which causes temperature cracking of hardened concrete. Therefore, temperature control of concrete curing is necessary for the continuous slip-up of slip form. In this study, the rebound hardness, time of ultrasonic waves propagation, heat of hydration, and external temperature are measured by developing heating panels and test devices for the continuous slip-up. Based on this, heating slip form is manufactured; this was applied to "Kimpo sites" and "Sinwol sites". The compared slip-up speed samples were 1.9 m/day or 0.200 m/hr on average at Gimpo sites (08:00~17:30) and 2.0 m/day or 0.210 m/hr at Sinwol sites.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.677-682
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• 2003

The physical properties of sintered body made from 3 kinds of slip, F (Flocculated), M (Moderate), and D (Dispersed) for coal fly ash 70-clay 30 (wt%) were studied in terms of slip states and pore size distribution of sintered bodies. The floc particle size distribution for slip F was wider than slip D and the slip F contained flocs larger than 11 $\mu\textrm{m}$. The pore size distribution of the green body of all slips ranged over 1∼4 $\mu\textrm{m}$. The pores smaller than 1 $\mu\textrm{m}$ almost disappeared during the sintering process, while the larger pore of 2.5∼3 $\mu\textrm{m}$ growed by 1 $\mu\textrm{m}$. The pore distribution for the green body of slip F became a narrow in width and high in height after sintering and the large pore limit in a slip F sintered body was 5.1 $\mu\textrm{m}$ which is smaller than that of other slip. The slip F rather flocculated was favorable over slip D well dispersed, in offering a higher compressive strength. From these results, the mechanical strength of sintered body is dependent on the pore distribution which could be controlled by dispersion state of the slips.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.10-15
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• 2019

In this paper, we report a robust steering control using time delay control for the vehicle dynamics variation due to tire/road contact condition variation, the lateral disturbance force due to the side wind, and the yaw disturbance moment due to the difference between the left and right tires' pneumatic pressure. We controlled the side slip and yaw damping compensation for rapid steering at the high velocity of the vehicle. Based on the developed control, the driver can only consider the desired path without concerning on the vehicle dynamics variation, disturbances, and undesired side slip and yaw oscillations. Simulation results show that robustness from the vehicle dynamics variation and disturbances was achieved by using the developed time delay control. We evaluated the side slip and yaw damping compensation capability for the rapid steering at the high velocity of the vehicle in the cases of three control methods.

• Magazine of the Korea Concrete Institute
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• v.3 no.2
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• pp.115-121
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• 1991

Slippage of beam longitudinal reinforcement at beam-column connections is an important cause of damage to reinforced concrete frames under static and dynamic loads, This paper summarizes the results of an experimen¬tal study on the effects of confinements and compressive strength of concrete on the local bond stress-slip cha¬racteristics of deformed bars. I t is concluded from experimental results that, as far as the bond splittmg cracks are restrained by the vertical column reinforcement, confinement of concrete by transverse reinforcement has insignigicant direct effect on the local bond behavior. The ultimate bond strength, however, Increases pro¬portionally with the square root of concrete compressive strength. An empirical model was developed for local bond st ressslip relationslip of deformed bars in confined concrete of different compressive strengths.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.596-599
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• 2000

벡터 제어이론은 교류전동기의 토오크와 자속을 독립적으로 제어할 수 있는 특징이 있으므로 토오크 제어를 주로 하는 견인용 전동기의 제어에 적용하기 위한 연구가 활발히 수행되어 왔다 그러나 선형 유도전동기 구동에는 아직 널리 사용되지 않은 실정이다 벡터 제어이론은 일반적으로 회전자자속 기준제어(Rotor flux oriented control)을 의미하며 이를 구현하기 위한 방법은 자속을 직접 측정 혹은 연산하는 직접제어 방식과 속도를 측정하여 슬립주파수 명령을 제어하는 간접방식으로 분류된다. 최근에는 기존의 회전자자속 기준방식뿐만 아니라 고정자자속(Stator flux oriented) 공극자속(Air gap flux oriented) 기준 방식등이 제안되고 있다. 본연구에서는 자기부상열차의 추진용 선형 유도 전동기의 추진에 가장 적합하다고 생각되는 고정자자속 기준벡터제어 방식과 이를 구현하기 위한 고정자 자속을 추정하는 방법에 대하여 설명한다. 또한 속도제어를 위한 속도 추정방식도 안내코일 등 부장치 없이 전동기 파라미터로 추정할 수 있는 기법에 대하여 논한다.