• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2002년도 춘계종합학술대회
• /
• pp.310-313
• /
• 2002

In industrial actual control system, PID controller has been used with its high delicate control system in position control system. PID controller has simple structure and superior ability in several characteristics. When the response of system is changed by delay time, variable load , disturbances and external environment, control gain of PID controller must be readjusted on the system dynamic characteristics. Therefore, a control ability of PID controller is degraded when the control gain is inappropriately determined. When the response characteristic of system is changed under a condition, control gain of PID controller must be changed adaptively to be a waited response of system. In this paper an PIDA controller is constructed by Two-Layers Neural Network applying back-propagation(BP) algorithm. Form the result of compute. simulation in the proposed controller, its usefulness is verified.

• 한국통신학회논문지
• /
• 제17권1호
• /
• pp.68-79
• /
• 1992

고속 아날로그 시스템,위성통신시스템, video signal processing 및 processing 및 optical fiber interface 회로등에서 높은 전자이동도로 인하여 고주파 툭성이 우수한 GaAs 연산 증폭기는 필수적인 구성 요소이다. 하지만, 낮은 전달컨덕턱스 및 low frequency dispersion등의 현상 때문에 높은 전압이득을 얻을 수 없다는 단점을 가지고 있다. 따라서 본 논문에서는 GaAs MESFETfmf 이용한 증폭기의 이득을 증가시키기 위한 기법을 비교분석하고 기존의 전류미러와 새로운 구성의 전류 미러를 설계하여 회로의 안정화를 꾀하였다. 높은 차동전압이득을 얻기 위하여 단일 증폭기의 bootstrap 이득증가기법을 이용하여 차종입력 회로를 구성하였으며, 회로의 안정도 및 우수한 주파수 특성을 얻기 위하여 common mode feedback을 사용하였다. Pspice를 통한 시뮬레이션 결과 설계된 회로의 이득이 18.6dB 향상되었고 안정도 및 주파수 특성면에서 우수함을 확인할 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.271-272
• /
• 2006

This paper presented a new experimental gain tuning technique for a Multi-Axis Servo System. First, the investigation for proportional gain of velocity control loop by using a Dynamic Signal Analyzer (DSA) was performed. Using the FUNCTION characteristic of DSA based on the Bode plot, the Bode plot of open loop transfer function was obtained. In turn, the integral gain of a servo controller can be found out by using the Integration time constant extracted from the Bode plot of open loop transfer function. In the meanwhile, the positional gain of the servo controller has been obtained by using the Bode plot of the closed loop transfer function. We have also proposed the technique to find out an optimal parameter of a notch filter, which has a great influence on vibration reduction, by using the damping factor extracted from the Bode plot of closed loop transfer function.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
• /
• pp.91-94
• /
• 1996

This paper presents an approach to estimation of learning gain in iterative learning control for discrete-time affine nonlinear systems. In iterative learning control, to determine learning gain satisfying the convergence condition, we have to know the system model. In the proposed method, the input-output equation of a system is identified by neural network refered to as Piecewise Linearly Trained Network (PLTN). Then from the input-output equation, the learning gain in iterative learning law is estimated. The validity of our method is demonstrated by simulations.

• 조명전기설비학회논문지
• /
• 제19권6호
• /
• pp.82-86
• /
• 2005

PID 제어기는 산업자동화 설비에 널리 쓰이고 있다. 하지만 시스템 특성이 간헐 또는 연속적으로 변화할 때에 정밀제어를 위한 새로운 매개변수 결정이 쉽지 않다. 이를 해결하기 위한 방법으로 본 논문에서는 PID 제어기와 같은 기능을 갖는 학습이득조절기를 제안하였다. 시스템의 적절한 학습이득은 델타 학습규칙에 의해서 결정된다. 제안된 학습이득 조절기의 기능은 직류 전동기의 모의실험에 의해 확인하였다.

• 한국정밀공학회지
• /
• 제23권6호
• /
• pp.88-95
• /
• 2006

In this paper, the gain-scheduled control design proposed in the previous paper has been applied to a target tracking system. In such system, it is needed to attenuate disturbance effectively as long as control input satisfies the given constraint on its magnitude. The scheduled gains are derived in the framework of linear matrix inequality(LMI) optimization by means of the MatLab toolbox. Its effectiveness is verified along with the simulation results compared with the conventional optimum constant gain and the scheduled gain control with constant Q matrix cases.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
• /
• pp.121-124
• /
• 2009

In this paper, the techniques and design focus of flexible gain coltrol of LAN(Low Noise Amplifier) using the TSMC 0.18um CMOS process. The design frequency set up a standard on 2.4GHz that is used in Zigbee system. The design concepts a basic Cascode LNA techniques and a swiching circuit consisted of 4 NMOS of load resistance, which convert the output impedenceby tuning on or off. The result show the gain change by NMOS operated swich. The simulation result is that Gain is 14.07dB-16.79dB and NF(Noise Figure) is 1.06dB-1.09dB.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.513-518
• /
• 2001

As the machining depth increases, the drilling torque increases and fluctuates and the risk of drill failure also increases. Hence, drilling torque control is very important to prevent the drill from failure. In this study, a PID controller was designed to control the drilling torque in a machining center. The plant including the feed drive system, cutting process, and spindle system was modeled for controller design. The Ziegler-Nichols rule was used to determine the controller gain and control action times. The root locus plot was used to tune the controller gain for a certain cutting condition. Also, suggested was a simple method to obtain the tuned controller gain for an arbitrary cutting condition not using the Ziegler-Nichols rule and root locus plot. The cutting torque control, performance of the designed controller and the effect of gain tuning on the control performance were examined.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2000년도 추계학술대회 논문집
• /
• pp.216-221
• /
• 2000

This paper deals with the Gain Control in the processing of the underwater acoustic image obtained from side scan sonar(SSS) system. At first, this paper describes the principles of SSS that is a surveying equipment for the underground of the rivers or dams as well as sea floor. Then this paper analyzes the cause and effects of the time varying intensity from the view point of transmission loss and beam pattern. At last, the time varying gain filter that is adopted by the towfish is introduced.

• Journal of Power Electronics
• /
• 제11권4호
• /
• pp.599-605
• /
• 2011

This paper proposes a gain scheduling method that improves the stability of grid-connected systems employing an LCL-filter. The method adjusts the current controller gain through an estimation of the grid impedance in order to reduce the resonance that occurs when using an LCL-filter to reduce switching harmonics. An LCL-filter typically has a frequency spectrum with a resonance peak. A change of the grid-impedance results in a change to the resonant frequency. Therefore an LCL-filter needs a damping method that is applicable when changing the grid impedance for stable system control. The proposed method instantaneously estimates the grid impedance and observes the resonant frequency at the same time. Consequently, the proposed method adjusts the current controller gain using a gain scheduling method in order to guarantee current controller stability when a change in the resonant frequency occurs. The effectiveness of the proposed method has been verified by simulations and experimental results.