• 한국정밀공학회지
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• 제18권10호
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• pp.161-167
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• 2001

This paper presents an approach to nonlinear engine idle controller and intake manifold absolute pressure(MAP) observer based on mean torque production model. A stable engine idle speed is important in that the unstable engine Idle mode can make engine to drooping or stall state. A sliding fuzzy controller has been designed to control engine idle speed under load disturbance. A sliding observer is also developed to estimate the intake manifold absolute pressure and compared with the actual MAP sensor value. The sliding mode observer has shown good robustness and good tracking performance. The inputs of sliding fuzzy controller are the errors of rpm and MAP. The output is a duty cycle(DC) for driving a idle speed control valve(ISCV).

• 한국정밀공학회지
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• 제12권7호
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• pp.138-147
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• 1995

The conventional PWM method, which was used in controlling the on-off valve, such as high-speed solenoid valve, was modulating the width of the pulse applied to the valve, by selecting arbitrary sampling time and modulating the duty-ratio in proportion to the error. However, in this method, a selection of long sampling time was inevitable and it was unable to get a high accuracy and a quick response. This study is for designing an appropriate controller for high-speed solenoid valve by proposing an improved duty-ratio modulation method using the Saw-toothed Carrier Wave which enables a short sampling time selection, high accuracy of control, and a quick response. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.319-322
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• 1997

In vector control technique, stator currents of an induction motor are transformed to equivalent d-q currents in reference frame consist of d and q axis, each of which is coincide with flux and torque direction respectively. In this paper, the new algorithm is suggested where the stator current through an induction motor torque is monitored by using a vector control method where an additional equipment is not need. The G-programming is used to apply the suggested algorithm in the experiment and this is applied to an actual system to monitor the torque value of an induction motor on real time. To solve the vibration trouble of estimated torque caused from an unbalanced real rotating speed of an induction motor and measured rotating speed by suggesting the reconstructed in a method based on measurement current signal. This produced system testifies an accuracy of an induction motor through the experiment by comparing the reference value of the control method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.327-331
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• 1997

This paper presents the non-linear modeling and design of a robust sliding mode controller for film transfer systems. The tension of a film is sensitive to the speed difference between a winder and an unwinder. The change of the roll-radius as well as the moment of inertia result in the film transfer system begin variable and non-linear. In designing the robust controller. Two major aims are considered. The first aim is hat the web transferring speed tracks at any given reference speed; the second one is that the tension of the film tracks at any given reference tension. To verify the control algorithm, a Simulink model was built and compared with a conventional PID controller. In a computer simulation study, the suggested robust sliding mode controller shows better performance than the PID controller a various control inputs.

• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.33-42
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• 2001

In switched reluctance motor(SRM) deives, the turn-on and turn-off angles of each phase switch should be accurately controlled for accuracy and efficiency. The accuracy of the switching angles is mainly dependent upon the resolution of the encoder and the sampling period of the microprocessor, that are used to provide the information of the rotor position and to implement a control algorithm of the SRM, respectively. Thus, the higher the speed of the SRM is increased, the larger the amount of the switching angle deviations are from preset turn-on and turn-off angles. Consequently, the motor can not be driven stably high speed region. There fore, a simples and low cost encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using a simple digital logic circuit is also presented for a wide speed range operation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.110-113
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• 2000

In general, speed control method of the elevator system has used motor pole change type or motor primary voltage control type. But it will change to vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control that primary current of the induction motor be controlled independently with magnetizing current(field current of DC motor) and torque current(armature current of DC motor). In this paper, by analyzing the effect of the time constant variation of rotor of the induction motor on the slip frequency type indirect vector control, a drive system for the motor will be constructed using a fuzzy slip frequency type indirect vector controller with fuzzy control method for estimating the vector time constant in the slip frequency type indirect vector control. The goal of this study is to enabling even more efficient speed control by constructing on elevator driver based on the newly developed drive system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.617-620
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• 2000

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. Is such technology has been rapidly developed, this field needs the positioning accuracy as high as submicron. It is expected that the accuracy of 10nm and 1nm is required in precision work and ultra precision work field, respectively by the beginning of 2000s. High speed and low vibration are also needed. This work deals with the design method and control system of Ultra precision positioning apparatus. We will examine the control performance and stability before manufacturing the real apparatus by using MATLAB SIMULINK based or pre-designed controller and system modeling.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.87-94
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• 2002

In order to manufacture a precision mold/die by machining, users need high speed ＆ precision mold/die machining center. So, for development of this machine, we intend to use linear motor that is instead of ball-screw, servo-motor and coupling, high-speed spindle of pressurized air journal bearing and composite materials. In this paper we research column moving type and table moving type. The former is mainly piling 3 axes on one moving body, the latter is consist of two independent carriages. Both types are available to high speed & precision machine, but we finally draw a conclusion column moving type due to an advantage of high-speed control of linear motor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.107-112
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• 2003

The recent machine tools are requested so high-quality processing and productivity increasing. Therefore, it is so necessary to develop technology for high-speed and high-precision. This thesis touches on the development of high speed and intellectual line center. At first, the line center is necessary that strong structure, compact structure and light weight design for high-speed processing and transfer. So, it is necessary that examination of new materials and structures for light-weight and control devices for precision processing. So, it is going to make mention of the process of 1st model production for the above-mentioned based on test model production and evaluation.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.429-435
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• 2002

In order to manufacture a precision mold/die by machining, users need high speed & precision mold/die machining center. So, for development of this machine, we intend to use linear motor that is instead of ball-screw, servo-motor and coupling, high-speed spindle of pressurized air journal bearing and composite materials. In this paper we research column moving type and table moving type. The former is mainly piling 3 axes on one moving body, the latter is consist of two independent carriages. Both types are available to high speed & precision machine, but we finally draw a conclusion column moving type due to an advantage of high-speed control of linear motor.