• 한국자동차공학회논문집
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• 제8권4호
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• pp.186-193
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• 2000

EPS(Electric Power Steering) systems have many advantages over traditional hydraulic power steering systems in space efficiency engine efficiency and environmental compatibility. In this paper an EPS system control logic using a torque map is proposed. The main function of the EPS system is to reduce the steering torque exerted by a driver by assist of an electric motor. Vehcile speed steering torque and steering wheel angle are measured and fed back to the EPS control system where appropriate assist torque is generated to assist the operator's steering effort. Another capability of the EPS system for easy adaptation to different steering feels via simple tuning is demonstrated by the experiments. It will be also verified that the EPS system can also improve damping and return performance of the steering wheel by control of the assist motor.

• 제어로봇시스템학회논문지
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• 제5권6호
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• pp.683-690
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• 1999

This paper deals with a fault-tolerant control method for robust control of RPV(Remotely Piloted Vehicle). To design the flight control system, the 6-DOF simulation program has been developed based on the dynamic model of RPV. A robust fault detection and diagnosis method proposed by Kwon et al. [8]-[10] is adopted to detect the actuator fault of RPV and to make the controller reconfiguration. The Hoo control method is applied to the flight control system. An integrated simulation for performance evaluation of the fault-tolerat\nt control system designed is performed via 6 DOF simulation and shows that the control system works even under the actuator fault.

• International Journal of Automotive Technology
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• 제6권3호
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• pp.269-275
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• 2005

The engine cooling system for a medium duty V6, 4.5 L diesel engine was modeled with a commercial code, GT-Cool in order to investigate the effect of controllable electric pump on the cooling performance and the fuel economy. The simulation results of the cooling system model with mechanical coolant pump were validated with experimental data. Two different types of electric pumps were implemented into the cooling system model and PID control for electric pump operation was incorporated into the simulation study. Based on the simulation result with electric pump, conventional thermostat hysteresis was modified to reduce pump operation for additional improvement of fuel economy, and then the benefit of electric pumps with modified thermostat hysteresis on fuel economy was demonstrated with the simulation. The predicted result indicates that the cooling system with electric pump and modified thermostat hysteresis can reduce pump power consumption by more than $99\%$ during the FTP 74 driving cycle.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.67-75
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• 2011

The development of electric vehicle power electronics system control, composed of DC-AC inverters and DC-DC converters, attract much research interest in the modern industry. A DC-AC inverter supplies the high-power motor torques of the propulsion system and utility loads of electric vehicles, whereas a DC-DC converter supplies the conventional low-power and low-voltage loads. However, the need for high-power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. The nonlinear control of power converters is an active research area in the field of power electronics. This paper focuses on the use of the fuzzy sliding mode strategy as a control strategy for buck-boost DC-DC converter power supplies in electric vehicles. The proposed fuzzy controller specifies changes in control signals based on the surface and knowledge on surface changes to satisfy the sliding mode stability and attraction conditions. The performance of the proposed fuzzy sliding controller is compared to that of the classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law, which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variations in load resistance and input voltage in the studied converter.

• International Journal of Automotive Technology
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• 제3권3호
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• pp.123-128
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• 2002

This paper presents the design of an active roll control system for a ground vehicle and an experimental study using an devised electric-actuating roll control system. Based on a three degree of freedom linear vehicle model, the controller is designed using lateral acceleration and rollrate feedback. In order to investigate the feasibility of an active control system, experimental work is carried out using a hardware-in-the-loop (Hil) setup which has been constructed by the devised electric-actuating system and the full vehicle model including tire characteristics. The performance is evaluated by an experiment using the Hil setup with limited bandwidth. Finally, in order to enhance the control performance in the transient region, a hybrid control strategy is proposed and evaluated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.416-418
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• 1997

Stable power source and fast control response are important for the generator excitation system. To stabilize the control of excitation circuit the PI controller for excitation current has been used. But the response of the system with this conventional control technique is very poor, especially in transient response with a predictive current control, the response of the excitation system can be improved. In this study, it is verified by the PSIM simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.550-554
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• 1997

It is important to select a reliable electronic control system in power plants because a trip of a power plant caused by malfunction of the control system can lead to a great deal of economic and social loss. In this paper. environmental test specifications for evaluating the reliability of the electronic control system were developed in order to select a reliable one. Also, the electronic control systems made by domestic manufacturers were tested based on these developed environmental test specifications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.567-569
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• 1997

A control system using a PLC has been developed for a single tower drier(STD) in a CANDU type nuclear power plant. This system will replace the existing STD control system which was implemented with mechanical timers and relays. The new control system makes it possible for an operator to perform more precise time and dew point control for the STD, thanks to the high efficiency and flexibility of the PLC. The operational cost for the control system is much reduced compared to the existing system.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1602-1613
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• 2014

The continuous growth of electric vehicles has caused electric power shortages in conventional utilities owing to the charging of electric-vehicle batteries. In order to increase the capacity of these utilities, photovoltaic systems may be an appropriate solution because of their benefits. However, a large amount of loss is generated in a conventional charging structure using photovoltaic sources owing to the many power conversion processes. This paper describes a simple integrated battery charger that utilizes a PV generation system. Moreover, the system control algorithm is deduced by analyzing the operation modes in order to control the proposed integrated system. The proposed system and algorithm are verified by a 3.3-kW prototype, resulting in an increase in the efficiency of approximately 7% to 15% compared with the conventional system. And, to examine the feasibility of the proposed system, the simulation for multi-charger with various conditions are progressed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2143-2145
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• 2003

In the linear system identification using the discrete time constant coefficients, there is a subspace method based on 4SID recently much suggested instead of the parametric method like as the maximum likelihood method. The subspace method is not related with the impulse response and difference equation in its input-output equation, but with the system matrix of the direct state space model from the input-output data. The subspace method is a very useful tool to adopt in the multivariable system identification, but it has a shortage unable to adopt in the closed-loop system identification. In this paper, we are suggested the methods to get rid of the shortage of the subspace method in the closed-loop system identification. The subspace method is used in the estimate of the output prediction values from the estimating of the state space vector. And we have compared the results with the outputs of the recursive least square method in the numerical simulation.