• 대한전기학회논문지:시스템및제어부문D
• /
• 제52권5호
• /
• pp.268-276
• /
• 2003

In this paper, we present a new control and monitoring technique for a power system using CAN(Controller Area Network). Feedback control systems having co'ntrol loops closed through a network(i.e. Ethernet, ControlNet, CAN) are called NCSs(Networked Control Systems). The major problem of NCSs is the variation of stability property according to time delay including network-induced delay and computation delay in nodes. We present a new stability analysis method of NCSs with time delay exploiting a state-space model of LTI(Linear Time Invariant) interconnected systems. The proposed method can determine a proper sampling period of NCSs that preserves stability performance even in NCSs with a dynamic controller. We design CAN nodes which can transmit control and monitoring data through CAN bus and apply these to NCSs for a power system. The results of the experiment validate effectiveness of our control and monitoring technique for a power system.

• 한국정밀공학회지
• /
• 제21권3호
• /
• pp.44-50
• /
• 2004

The conventional sliding mode control(SMC) technique requires a prior knowledge of the upperbounds of external disturbance to guarantee a robust control performance. This, however, may not be easy to identity in practice. This paper presents a new methodology, sliding mode control with disturbance estimator(SMCDE), which offers a robust control performance without a prior knowledge of the upperbounds. The proposed technique is featured by an integrated average value of the imposed disturbance over a certain period. The proposed technique is applied to the position control of AC servo motor, and experimental results are compared between the conventional and proposed schemes.

• 한국소음진동공학회논문집
• /
• 제19권2호
• /
• pp.169-175
• /
• 2009

This paper presents motion control of the Inchworm composed of the piezoelectric actuators and mechanical elements. Piezoelectric actuator shows nonlinear response characteristics including hysteresis due to the ferroelectric characteristics. This paper proposes feedback control scheme to improve the ability of tracking response to complex input signal and suppress the phenomenon of hysteresis using the sliding mode control technique with the integrator. The sliding mode control system has the limit to minimize both the settle time and overshoot. For making up this limit, this paper also suggests input shaping technique suitable to the inchworm control system.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1625-1628
• /
• 2003

Recently the VR technique has evolved into a mixed reality (MR) technique, in which a user can observe a real world in front of him/her as well as virtual objects displayed. This has been realized by the employment of a see-through type HMD (S-HMD). We have been developing a mixed reality space employing the MR technique. The objective of our study is to realize a virtual human that acts as a man-machine interface in the real space. It is important in the study to create a virtual human acting naturally in front of a user. In order to give natural motions to the virtual human, we employ a developed motion capture technique. We have already created various 3-D human motion models by the motion capture technique. In this paper, we present a technique for creating a virtual human using a human model provided by a computer graphics software, 3D Studio Max(C). The main difficulty of this issue is that 3D Studio Max(C) claims 28 feature points for describing a human motion, but the used motion capture system assumes less number of feature points. Therefore a technique is proposed in the paper for producing motion data of 28 feature points from the motion data of less number of feature points or from incomplete motion data. Performance of the proposed technique was examined by observing visually the demonstration of some motions of a created virtual human and overall natural motions were realized.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
• /
• pp.57-60
• /
• 1999

An optimal control technique designed for simultaneous tracking and quality control for batch processes. The proposed technique is designed by transforming quadratic-criterion based iterative learning control(Q-ILC) into linear quadratic control problem. For real-time quality inferential control, the quality is modeled by linear combination of control input around target qualify and then the relationship between quality and control input can be transformed into time-varying linear state space model. With this state space model, the real-time quality inferential control can be incorporated to LQ control Problem. As a consequence, both the quality variable as well as other controlled variables can progressively reduce their control error as the batch number increases while rejecting real-time disturbances, and finally reach the best achievable states dictated by a quadratic criterion even in case that there is significant model error Also the computational burden is much reduced since the most computation is calculated in off-line. The Proposed control technique is applied to a semi-batch reactor model where series-parallelreactions take place.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2004년도 추계학술대회 학술발표 논문집 제14권 제2호
• /
• pp.443-446
• /
• 2004

This paper discusses an intelligent digital redesign technique for designing a fuzzy pulse-width-modulated (PWM) control. First when we are given a well-designed fuzzy analog control, the equivalent digital control is intelligently redesigned. Using the similar technique we intelligently redesign the fuzzy PWM control from the intelligently redesigned fuzzy digital control. A stabilizability of the intelligently redesigned PWM control is rigorously analyzed.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
• /
• pp.440-443
• /
• 1995

A control strategy for random parametic system by using FLC is investigated and developed. In the course of research, as a first part, nonlinear system under random disturbance is investigated. Preliminary results is presented in the paper. A control technique, GA based FLC, is employed successfully for inverted pendulum experiencing white noise excitation.

• 한국통신학회논문지
• /
• 제29권4A호
• /
• pp.363-369
• /
• 2004

본 논문에서는 파장분할다증(WDM) 첨가(add)/절취(drop)망에서 채널의 add/drop에 따라 망 내에 있는 EDFA의 이득을 제어함에 있어 세계 최초로 외란 간측기법을 적용하는 새로운 이득-클램핑(gain-clamping) 방법을 제안한다. 이득-클램핑을 위한 제어신호는 공칭 제어신호와 채널의 add/drop에 따른 이득변동을 보정하기 위한 부가제어신호로 구성된다. 외란 관측기법에 근거하여, 부가 제어신호는 채별의 add/op에 의해 발생하는 추정 외란을 보정할 수 있도록 설계하였다. 이러한 부가 제어신호를 생성하는 회로는 간단한 전자소자를 이용하여 쉽게 구현할 수 있다. 모의실험을 통해 본 논문에서 제안하는 방법을 사용할 때 채널의 add/drop 과정에서 EDFA의 출력 파형에 나타나는 이득변화에 따른 요철이 최소로 됨을 보여줌으로써 본 방법이 기존의 여타 방법들에 비해 월등함을 입증하였다.

• 제어로봇시스템학회논문지
• /
• 제11권6호
• /
• pp.524-529
• /
• 2005

In this paper, a novel neural network compensation technique for PD like fuzzy controlled robot manipulators is presented. A standard PD-like fuzzy controller is designed and used as a main controller for controlling robot manipulators. A neural network controller is added to the reference trajectories to modify input error space so that the system is robust to any change in system parameter variations. It forms a neural-fuzzy control structure and used to compensate for nonlinear effects. The ultimate goal is same as that of the neuro-fuzzy control structure, but this proposed technique modifies the input error not the fuzzy rules. The proposed scheme is tested to control the position of the 3 degrees-of-freedom rotary robot manipulator. Performances are compared with that of other neural network control structure known as the feedback error learning structure that compensates at the control input level.

• 한국멀티미디어학회논문지
• /
• 제18권11호
• /
• pp.1400-1407
• /
• 2015

In the paper, we suggest bettered EHMECS(Enhanced Hybrid Multi Electrical Cupping System) to regulate automatically vacuum pressure using many cupping cup at once. We controlled accurately the pressure using S-PI control technique in pump motor to input the air inside cupping cup. S-PI control compared constant velocity, load and velocity variance between existing PI and FLC(Fuzzy Logic Control). The stabilization time of suggested S-PI control improve 20% of existing PI and 8% of FLC. The error constant of normal condition improved 71% of existing PI and 62% of FLC in steady speed and 80% of existing PI and 67% of FLC in load change. Also the error constant about velocity variance improve 45% of PI control. It is prove the suggested S-PI control technique. When use long time vacuum pressure of cupping cup regulated the suggested S-PI control technique, can loosen knotted muscles.