• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.5
• /
• pp.793-800
• /
• 2004

The purpose of this study is to develope a servo system with faster and more accurate response. This paper describes a method of approximate reasoning for fuzzy control of servo system based on the decomposition of $\alpha$-level fuzzy sets. We propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion cases where the output variable u directly is generated PWM The effectiveness for robust and faster response of the fuzzy control scheme are verified for a variable parameter by comparison with a PID control and fuzzy control A position control of DC servo system with a fuzzy logic controller is demonstrated successfully.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.127-129
• /
• 2008

This paper describes a method of approximate reasoning for fuzzy control of servo system, based on decomposition of -level fuzzy sets. It is propose that logic circuits for fuzzy PI+PD are a body from fuzzy inference to defuzzificaion in cases where the output variable u directly is generated PWM. The effectiveness for robust and faster response of the fuzzy control scheme is verified for a variable parameter by comparison with a PID control and fuzzy control. A position control of DC servo system with a fuzzy logic controller successfully demonstrated.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1993.06a
• /
• pp.785-788
• /
• 1993

This paper presents the prototype framework for automated integration of CMOS current-mode fuzzy logic circuits using an intelligent module approach. The library of modules representing the standard fuzzy logic operators was built. These modules were finally used to synthesized sophisticated fuzzy logic units. Fuzzy unit designs were made based upon the results of a newel methodology of the current mirror-based fuzzy logic function synthesis. This methodology is actually incorporated into the presented framework. As an example, the membership function unit was synthesized, simulated, and the final layout was generated using the presented framework. Finally, the fuzzy logic controller unit (FLC) was generated using the proposed framework. Simulation as well as measurement results show unquestionable advantages of the proposed fuzzy logic function integration system over the classical design methodology with respect to the area, relative error and performance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.5 no.1
• /
• pp.49-53
• /
• 1980

Since Zadeh had published the fuzzy set theory at 1965, it has been applied to many fields such as realizability of communication nets, automatic control, learning systems, switching circuits. In this paper, the method of applying a fuzzy logic to a pattern classification is studied and the difference of fuzzy logic from Boolean algebra is discussed. Classfication experiment is carried out 16 persons' photos of three families by fourty male and female observers and recognition rate 94% is obtained.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.195-198
• /
• 2000

It is possible to perform the digital fuzzy logical high-speed and high-precision computation by the use of redundantly-represented binary positive-digit number arithmetic operation. In this paper, as basic operation circuits in the fuzzy logic new voltage-mode 4-valued binary parallel processing operation circuits using positive redundantly-expressed binary-coded numbers is discussed.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.8
• /
• pp.2528-2535
• /
• 2000

Technology mapping is a part of VLSI CAD system, where circuits in logical level are mapped into circuits in physical level. The performance of technology mapping system is evaluatecJ by the delay and area of the resulting circuits. In the sequential circuits, the delay of the circuit is decided by the maximal delay between registers. In this work, we introduce an FPGA mapping algorithm improved by retiming technique used in constructive level and iterative level, and by fuzzy logic technique. Initial circuit is mapped into an FPGA circuit by constructive manner and improved by iterative retiming. Criteria given to the initial circuit are structured hierarchically by decision-making functions of fuzzy logic. The proposed system shows better results than previous systems by the experiments with MCNC benchmarkers.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.8
• /
• pp.1246-1253
• /
• 2009

This paper presents derived a calculating form of fuzzy inference, based on decomposition of $\alpha$-level sets. Based on the calculating form it is propose that fuzzy logic circuits of PI+PD controller are a body from fuzzy inference to defuzzificaion in cases where the command variable u directly is generated PWM. The effect of quantization on $\alpha$-levels is investigated. with input/out characteristics of fuzzy controller by simulation. It is concluded that 4 quantization levels are sufficient result for fuzzy control performance of DC servo system. Simulation and experimental results demonstrated that the hardware implementation of the proposed controller can successfully provide good performance on the position control of DC servo system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.5
• /
• pp.1050-1057
• /
• 2004

The purpose of study is development of a fuzzy controller which independent of a computer and its software for fuzzy control of servo system. This paper describes a method of approximate reasoning for fuzzy control of servo system, based on decomposition of $\alpha$-level fuzzy sets, It is propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion in cases where the output variable u directly is generated PWM. The effectiveness of quantified $\alpha$-levels on input/output characteristics of fuzzy controller and output response of DC servo system is investigated. It is concluded that $\alpha$-cut 4 levels give a sufficient result for fuzzy control performance of DC servo system. The experimental results shows that the proposed hardware method is effective for practical applications of DC servo system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1993.06a
• /
• pp.1402-1405
• /
• 1993

In this paper, a fault evaluation method is proposed, which is to determine whether analog electronic circuits are faulty or not. In our method, evaluation characteristics of an expert test engineer are defined by means of directed graphs. By performing a multi-stage fuzzy inference based on the graphs, novice test engineers can derive a fault evaluation result satisfied by the expert. The effectiveness of our method is checked by some experiments for an amplifier circuit.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.5
• /
• pp.595-604
• /
• 2011

A three-phase three-level shunt active filter controlled by fuzzy logic current controller which can compensate current harmonics generated by nonlinear loads is presented. Three-level inverters and fuzzy controllers have been successfully employed in several power electronic applications these past years. To improve the conventional pwm controller performance, a new control scheme based on fuzzy current controller is adopted for three-level (NPC) shunt active filter. The scheme is designed to improve compensation capability of APF by adjusting the current error using a fuzzy rule. The inverter current reference signals required to compensate harmonic currents use the synchronous reference detection method. This technique is easy to implement and achieves good results. To maintain the dc voltage across capacitor constant and reduce inverter losses, a proportional integral voltage controller is used. The simulation of global system control and power circuits is performed using Matlab-Simulink and SimPowerSystem toolbox. The results obtained in transient and steady states under various operating conditions show the effectiveness of the proposed shunt active filter based on fuzzy current controller compared to the conventional scheme.