• 제어로봇시스템학회논문지
• /
• 제6권7호
• /
• pp.537-543
• /
• 2000

mathematical models for a hydraulic brake actuator and a brake control law for vehicle collision warning/collision avoidance (CW/CA) systems will be presented in this paper. The control law have been designed for optimzied safety and comfort. A solenoid-valve-controlled hydraulic brake actuator system for the CW/CA systems has been investigated, A nonlinear computer model and a linear model of the hydraulic brake actuator system have been developed. Both models were found to represent the actual system with good accuracy. Uncertainties in the brake actuator model have been considered in the design of the control law for the roubustness of the controller. The effects of brake control on CW/CA vehicle response has been investigated via simulations. The simulations were performed using the hydraulic brake system model and a complete nonlinear vehicle model. The results indicate that the proposed brake control law can provide the CW/CA vehicles with an opimized compromise between safety and comfort.

• Journal of Electrical Engineering and Technology
• /
• 제12권3호
• /
• pp.1292-1298
• /
• 2017

In this paper, we represent a nonlinear identification of electronic brake pedal behavior in the brake-by-wire (BBW) system based on hybrid group method of data handling (GMDH) and genetic algorithm (GA). A GMDH is a kind of multi-layer network with a structure that is determined through training and which can express nonlinear dynamics as a mathematical model. The GA is used in the GMDH, enabling each neuron to search for its optimal set of connections with the preceding layer. The results obtained with this hybrid approach were compared with different nonlinear system identification methods. The experimental results showed that the hybrid approach performs better than the other methods in terms of root mean square error (RMSE) and correlation coefficients. The hybrid GMDH/GA approach was effective for modeling and predicting the brake pedal system under random braking conditions.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
• /
• pp.302-304
• /
• 1996

In this paper, a new algorithm for sensorless speed control of switched reluctance motor (SRM) is proposed. It is based on the measurement of initial rate of change of phase current. The initial rate of rise of phase current mainly depends up on the phase inductance at the time instant when the phase is excited. Therefore, the measurement of initial di/dt permits rotor position estimation, which is used to trigger the next phase. In the proposed technique, there is no need to generate additional current pulses when a phase is not excited. Therefore, this scheme does not introduce the unwanted braking torque. Also, only one current measurement is made every time a phase is excited. This reduces the computational load on the micro-controller and enhances the speed range of the sensorless drive. By using this scheme it is possible to implement the sensorless control of SRM using low cost micro-controller.

• 전기학회논문지
• /
• 제63권10호
• /
• pp.1479-1484
• /
• 2014

This paper deals with regenerative energy in railway system which one of the largest customer in terms of load capability. Unlike the other loads of power system, loads of railway systems change in time and space. It has a characteristic amount of generating regenerative energy by frequent starting and braking in railway system. Therefore, it is expected higher utilization in railway system than the other systems. The purpose of DC power supply simulation is analyzing backed energy, regenerative energy by each railway vehicle and substation. In this paper, regenerative energy utilization are analyzed using DC power supply simulation and it is performed changing major influence on the design such as the number of installing absorber, internal resistance value, no-load voltage value at substation or operating parameters at regenerative energy utilization. After simulating, results are compared and analyzed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.273-275
• /
• 2005

The national need to establish a new stray current mitigation method to protect the underground metallic infrastructures in congested downtown area forced us to design and develop the distributed impressed current cathodic protection (DICCP) system. The main purpose of this system is to replace the stray current drainage bond methods, which is widely adopted by pipeline owners in Korea. Currently, forced drainage makes up about 85% of total drainage facilities installed in Korea because polarized drainage can neither drain perfectly the stray currents during normal operation of electric vehicle nor drain the reverse current during regenerative braking at all. The forced drainage, however, has been abused as an alternative cathodic protection system, which impresses currents from rails to the pipelines and accordingly uses the rails as anodes. As a result, it is necessary to consider a new method to both cathodically protect the pipelines and effectively drain the stray currents. In this paper, we describe the design parameters and installation schemes of DICCP system that can meet these demands.

• 드라이브 ㆍ 컨트롤
• /
• 제16권3호
• /
• pp.67-74
• /
• 2019

The automotive market has recently been investing much time and costs in improving existing technologies such as ABS (Anti-lock Braking System) and TCS (Traction Control System) and developing new technologies. Additionally, various methods have been applied and developed to reduce this. Among them, the development method using the simulation has been mainly used and developed. In this paper, we have studied a method to develop SILS (Software In the Loop Simulation) for TCS which can test various environment variables under the same conditions. We modeled hardware (vehicle engine and ABS module) and software (control logic) of TCS using MATLAB/Simulink and Carsim. Simulation was performed on the climate, road surface, driving course, etc. to verify the TCS logic. By using SILS to develop TCS control logic and controller, it is possible to verify before production and reduce the development period, manpower and investment costs.

• 지질공학
• /
• 제12권1호
• /
• pp.53-61
• /
• 2002

국내의 경우는 국토의 70%이상이 산지로 구성되어 있어 도로 개설에 따라 필연적으로 절개면이 발생된다. 더욱이 여름철에 집중적으로 발생하는 태풍, 장마에 의해 절개면의 붕괴가 많이 발생하고 있다. 국내 도로절개면 붕괴 중 낙석이 차지하는 비중이 40.8%이며, 토사붕괴는 29.5%를 차지한다. 낙석의 경우, 절개면 상부 암석의 자유운동에 의해 빠른 시간 내에 발생하고, 토사붕괴의 경우, 집중강우와 관련 쇄설성 유동형태로 도로이용에 많은 인명 및 재산피해를 유발한다. 특히 자동차 운행속도와 토사 붕괴 및 낙석이 떨어지는 속도와의 관계를 고려할 대 불과 몇 초의 짧은 시간에 인명피해를 발생시키게 된다. 본 연구는 최근 국도 주변 붕괴 현장 자료를 분석하고 국내 도로절개면의 특성과 붕괴유형을 근거로 낙석 및 쇄설성 유동에 대한 인명피해를 최소화하기 위한 방안으로 낙석 및 쇄설성 유동 발생시 이동시간, 절개면 통과 차량의 속도와 정지거리의 상관성을 검토하여 도로 경보시스템의 설치기준을 제시하는데 있다. 경보시스템은 낙석발생과 동시에 작동하여 운전자로 하여금 붕괴위치로의 이동을 사전에 차단시킴으로 피해를 최소화한다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.1618-1628
• /
• 2011

The Train Diagnostic and Control System(TDCS) has been equipped on the modern Metro Vehicle, Locomotive and High Speed Train. The main purpose of this system is to support the identification of train status by real-time, the fast action against such failure events during revenue service and the fast convenient maintenance processes. Some of newest TCMS, a kind of control and monitoring system, has participated in the main control functions such as pantograph up and down, powering and braking command and so on. But these kind of control functions of the high speed train which has the operating speed over 300km/h are conducted by the train electrical logic circuits. The KTX-I and KTX-II - the local high speed train, are the typical example. The next generation TDCS for the ongoing project of distributed high speed train(HEMU) is designing with the target to increase main train control functions, to increase the reliability/avalibility and to increase the convenient driving. This paper introduces the overall configurations and functions of the new generation TDCS.

• Journal of Power Electronics
• /
• 제15권3호
• /
• pp.849-859
• /
• 2015

This paper proposes a novel compound-type hybrid energy storage system (HESS) that inherits the unique advantages of both battery/supercapacitor (SC) and the SC/battery HESSs for electric vehicles (EVs). Eight operation modes are designed to match this system. A mode control strategy is developed for this HESS on the basis of these modes, and five classes of operation modes are established to simplify this strategy. The mode control strategy focuses on high operating efficiency and high power output. Furthermore, the compound-type HESS is designed such that the SC is the main priority in braking energy absorption. Thus, this HESS can operate efficiently and extend battery life. Simulation results also show that the compound-type HESS can not only supply adequate power to the motor inverter but can also determine suitable operation modes in corresponding conditions. Experimental results demonstrate that this HESS can extend battery life as well. The overall efficiency of the compound-type HESS is higher than those of the battery/SC and the SC/battery HESSs.

• 제어로봇시스템학회논문지
• /
• 제21권2호
• /
• pp.137-144
• /
• 2015

In hybrid or electric vehicles, the hydraulic brake system must be controlled cooperatively with the traction motor for regenerative braking. Recently, a motor driven brake system with a PMSM (Permanent Magnet Synchronous Motor) has replaced conventional vacuum boosters to increase regenerative power. Unlike industry motor controls, additional source codes such as functional safety are essential in automotive applications to meet ISO26262 standards. Therefore, the control logic execution time increases, which also causes an extension of the motor current control period. The increased current control period makes precise motor current control challenging inhigh speed ranges where the motor is driven by high frequency. In this paper, a PWM update strategy and a time delay compensation method are suggested to improve current control and system performance. The proposed methods are experimentally verified.