• 한국정밀공학회지
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• 제22권8호
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• pp.64-70
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• 2005

The development of an accurate and energy saving pneumatic regulator that may be applied to a variety of practical pressure control applications is described in this paper. A novel modified pulse width modulation(MPWM) valve pulsing algorithm allows the pneumatic regulator to become energy saying system. A comparison between the system response of conventional PWM algorithm and that of the modified PWM(MPWM) algorithm shows that control performance is almost the same, but energy saving is greatly improved by adopting this new MPWM algorithm. The effectiveness of the proposed control algorithm are demonstrated through experiments with various reference trajectories.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.822-828
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• 2018

AC-DC conversion is a necessary for the systems that require DC source. This conversion has been done via rectifiers based on controlled or uncontrolled semiconductor switches. Advances in the power electronics and microprocessor technologies allowed the use of Pulse Width Modulation (PWM) rectifiers. In this paper, dq-axis current and DC link voltage of three-phase PWM rectifier are controlled by using type-2 fuzzy neural network (T2FNN) controller. For this aim, a simulation model is built by MATLAB/Simulink software. The model is tested under three different operating conditions. The parameters of T2FNN is updated online by using back-propagation algorithm. The results obtained from both T2FNN and Proportional + Integral + Derivate (PID) controller are given for three operating conditions. The results show that three-phase PWM rectifier using T2FNN provides a superior performance under all operating conditions when compared with PID controller.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.313-315
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• 2009

In this thesis, A methodology of system implement for PID controller, PWM logic, HSC logic, Host Communication and external DAC interface are implemented into single FPGA chip is proposed. The implemented system is used to control the speed of DC servo motor. A DATA block transfers set point value(SV) and P, I, D gain parameters to the corresponding Blocks respectively by the Host Communication to Computer. A HSC block generates process value(PV) by a pulse and $90^{\circ}$ shifted pulse from the encoder A PID block makes error(E) signal from the set value and process value and output manufacture value(MV) through the PID controller. In PWM block using the MV from the PID block, drives H-bridge controlling the Motor. Also DAC interface controls the DAC to graph the digital signal such as SV, PV, E, MV in FPGA onto the Oscilloscope.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.236-243
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• 1999

This study deals with the application of high speed on-off valves to an electro-hydraulic servo indexing system incorporated electro-hydraulic servo valces. Comparing with the electro-hydraulic servo valve the high speed on-off valve has some merits. Which included low price robustness to the oil contamination and dircect control without D/A converter. The considered sys-tem of this study is controlled by pulse width modulation(PWM) of the control law which is pro-duced by a PID controller which is used broadly in industrial equipments. The dynamic character-istics corresponding to variations of system parameters such as inertia moment system gain and supply pressure are investigated by computer simulation and experiment. Consequently the availability of the application of high speed on-off valve to servo indexing system instead of electro-hydraulic servo valve is confirmed.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.191-201
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• 1997

Accurate positioning of a throttle valve is required to implement the traction control system(TCS) which improves acceleration performance in slippery roads. In this research, position control system is developed for the main throttle actuator(MTA) system which uses one throttle actuation for small volume and DC servo motor for fast response. In order to drive DC motor, PWM signal generator and PWM amplifier were built and interfaced to the motor and controller. Digital PID control law is used as basic control algorithm. In order to prevent overshoot and improve accuracy, velocity profiles are generated and implemented whenever the targer throttle angle is given from the TCS controller. Thanks to velocity profiles, the control performance was very good and only one set of PID gains was used to cover the entire operating range. Also, the resolution of position is about 0.4$^{\circ}C$, which is better than that of stepping motor also used as throttle actuator in some products. The response time of the developed system is also fast enough to implement the engine control based TCS algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1784-1787
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• 2005

In this paper, proportional modulator which controls the second pressure of the pneumatic system was studied and proportional operating of modulator was gotten by two digital valves that have a fast dynamic characteristics and were controlled by PWM operating method. In order to more precision pressure control, this modulator consist of not only high speed two digital valves but also pressure sensor, measurement equipment and controller having a microprocessing function. In this study, for the development of the new proportional modulator, various research such as PWM control method, test equipment manufacturing, testing and evaluation were accomplished.

• Journal of Advanced Marine Engineering and Technology
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• 제23권3호
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• pp.369-378
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• 1999

This paper presents position control of an electro-hydraulic servo system whoch is operated by four 2-2way high speed on-off valves with either PWM PID control method or sliding mode control method, The advantages of using high speed on-off valves instead of electo-hydraulic servo valves or electro-hydraulic proportional valves are low price robustness for oil contamination and direct control without a D/A converter. The system consists of load cylinder inertia car potentiometer and external load cylinder. The experiments were carried out under several conditions and the results were compared. As a result the sliding mode method has shown good control performance and the robust and stable positioning of the elector-hydraulic servo system can be achieved accurately.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.472-477
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• 1994

The lockup clutch is embeded on torque converter of automatic transmission to prevent the efficiency deterioration of torque converter in high speed. For improving fuel consumption rate, it is desirable to engage the lockup clutch earlier. But, it results in degrading shift quality, due to the transient torque. The transient clutch pressure which affects the shifting quality, should be controlled properly. In this study, to solve the problem, it is analysed the hydraulic circuit of lockup system including line pressure regulating circuit, established the nonlinear model, and designed the PID controller. The line pressure is supplied to the lockup clutch through the lockup control valve by switching the lockup solenoid valve on. In order to control the transient pressure actively, it is needed to control the lockup solenoid valve by closed loop control. The lockup solenoid valve is 2-way on-off valve, and is adequate for PWM control. To reduce the pressure chattering, the carrier frequency is increased. Target pressure profile is computed from optimized velocity difference profile throuth dynamic equation of vehicle system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.971-974
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• 2003

본 논문은 DC Motor의 속도 제어를 위해서는 속도를 결정해주는 PWM 출력과 Motor의 속도를 측정할 수 있는 고속카운터가 필요하며 설정한 값과 실제 출력되는 값을 동일하게 만들어주는 제어부분을 구현하여야 하며 시스템을 구성하기 위한 주변 I/O도 구성되어야 한다. 기존 마이크로프로세서로 구현을 하게 되면 PWM 출력과 제어 알고리즘에 대한 연산 및 주변 I/O에 대한 구현이 용이하겠지만 DC Motor의 Encoder에서 나오는 신호를 카운터하기에는 부족한 측면이 많으며 마이크로프로세서의 연산처리 과정에 따라 제어 알고리즘 연산에 소비되는 시간도 FPGA로 구현한 시스템보단 상대적으로 여유가 없다. 본 논문에서는 FPGA만을 이용하여 PWM, HSC, PID, 주변 I/O등을 하나의 Chip에 System On Chip화함으로 실제 시스템에 적용할 때 제어시스템의 소형화와 제어대상을 고속의 정확성있는 제어시스템을 연구 하였다.

• 전자공학회논문지
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• 제51권11호
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• pp.211-220
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• 2014

본 논문에서는 하나의 FPGA 내에 DC 모터 제어와 TFT LCD 인터페이스가 내장되어, 제어와 결과 데이터의 실시간 분석이 용이하고 컴팩트한 전(full)-FPGA 기반 모터 제어 시스템을 보인다. PID 속도 제어 모듈과 TFT LCD 상에 실험 결과를 실시간 보여주기 위한 모니터링 모듈을 하나의 FPGA내에 설계하고, 시뮬레이션과 실험을 통하여 유용성을 보인다. FPGA로는 xc3s400를 사용하였고, AD (Aaltium Designer)를 이용하여 전체 시스템을 설계하였다. DC 모터 4상한 운전을 위해 MOSFET를 이용한 PWM 모터 드라이버를 제작하였다.