• 센서학회지
• /
• 제33권1호
• /
• pp.12-17
• /
• 2024

Floating inverter amplifiers (FIAs) have recently garnered considerable attention owing to their high energy efficiency and inherent resilience to input common-mode voltages and process-voltage-temperature variations. Since the voltage gain of a simple FIA is low, it is typically cascaded or cascoded to achieve a higher voltage gain. However, cascading poses stability concerns in closed-loop applications, while cascoding limits the output swing. This study introduces a gain-enhanced FIA that features cross-coupled body biasing. Through simulations, it is demonstrated that the proposed FIA designed using a 28-nm complementary metal-oxide-semiconductor technology with a 1-V power supply can achieve a high voltage gain (> 90 dB) suitable for dynamic open-loop applications. The proposed FIA can also be used as a closed-loop amplifier by adjusting the amount of positive feedback due to the cross-coupled body biasing. The capability of achieving a high gain with minimum-length devices makes the proposed FIA a promising candidate for low-power, high-speed sensor interface systems.

• International Journal of Air-Conditioning and Refrigeration
• /
• 제10권2호
• /
• pp.106-115
• /
• 2002

The performance of an inverter-driven water-to-water heat pump with an electronic expansion valve (EEV) was measured as a function of compressor frequency, load conditions, and EEV opening. Based on the test results, a controller using proportional integral (PI) feedback or PI feedforward algorithm was designed and tested to investigate capacity modulation and transient response control of the system. Although the relation between superheat and EEV opening of the heat pump showed nonlinear characteristics, a control gain obtained at the rated frequency was applicable to various operating conditions without causing large deviations. When the simple PI feedback control algorithm was applied, a large overshoot of superheat and wet compression were observed due to time delay effects of compressor frequency. However, applying PI feedforward control scheme yielded better system performance and higher reliability, compared to the PI feedback algorithm.

• 대한전자공학회논문지
• /
• 제5권1호
• /
• pp.13-25
• /
• 1968

고주파용 transistor를 이용한 광대역증폭기를 hybrid-π 등가회로를 이용하여 상세하게 분석하였다. 저주파와 고주파의 경우에 관한 해석을 하였고 이득과 대역폭및 입력 impedance와 출력 impedance를 주는 식을 유도하였다. 직렬궤환증폭기는 전압원으로 구동하여야하며 저저항부하로 동작시켜야 하고 병렬궤환증폭기는 전류원으로 구동하여야 하며 고저항부하로 동작시켜야 하는 것을 표시하였고 이 두가지 증폭단은 완충증폭단이나 변압기결합을 하지않고 결합시킬 수 있음을 표시하였다.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권12호
• /
• pp.542-548
• /
• 2002

We consider an unknown linear time invariant plan with static load disturbance. A saturation function nonlinear element is sued to find th one point information in the frequency domain. We analyze an asymmetric self-oscillation caused by static load disturbance with relay feedback and saturation function feedback. We propose a new method to tune a PID controller using a saturation nonlinear feedback element in the presence of asymmetric oscillation. The proposed method does not require the knowledge of plant d.c. gain with an asymmetric oscillation in the plat output.

• International Journal of Aeronautical and Space Sciences
• /
• 제12권2호
• /
• pp.179-189
• /
• 2011

In this paper, robust adaptive control design problem is addressed for a class of parametrically uncertain aeroelastic systems. A full-state robust adaptive controller was designed to suppress aeroelastic vibrations of a nonlinear wing section. The design used leading and trailing edge control actuations. The full state feedback (FSFB) control yielded a global uniformly ultimately bounded result for two-axis vibration suppression. The pitching and plunging displacements were measurable; however, the pitching and plunging rates were not measurable. Thus, a high gain observer was used to modify the FSFB control design to become an output feedback (OFB) design while the stability analysis for the OFB control law was presented. Simulation results demonstrate the efficacy of the multi-input multi-output control toward suppressing aeroelastic vibrations and limit cycle oscillations occurring in pre- and post-flutter velocity regimes.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 하계학술대회 논문집 A
• /
• pp.465-467
• /
• 1994

A VSC with Inertial COFB(Coordinate-Operator Feedback) is presented for chattering alleviation. Athought the conventional sliding mode controller has good properties of robustness for disturbances or parameter variations, fast response, and easy implementation, there exists an inevitable chattering problem which deteriorates the control performance of system. VSC using Inertial COFB has properties of bounded feedback gain, reduced chattering, and robustness for disturbances or parameter variations. The validity of the proposed method is demonstrated through computer simulation for a position control of BLDCM.

• Journal of Mechanical Science and Technology
• /
• 제15권6호
• /
• pp.699-708
• /
• 2001

This paper presents a new approach to the AFR (Air-to-Fuel Ratio) control problem, which is based on the wide-band oxygen sensor output. The dedicated nonlinear controller is based on the feedback lineaization technique. It is well known that the feedback linearizing control technique requires an exact model of the plant for the cancellation of plant nonlinearities. A sliding mode control scheme is applied which can effectively compensate the modeling uncertainties. The measurement time delay of an oxygen sensor limits the gain of the feedback controller. Hence, time delay compensation procedure is necessary for the improvement of control performance. The Smith predictor is adopted to compensate the effects of time delay. The simulation and experimental results show that the proposed controllers can effectively reduce the transient peaks of AFR in spite of fast tip-in and tip-out maneuvers of the throttle.

• 한국통신학회논문지
• /
• 제17권4호
• /
• pp.361-370
• /
• 1992

수직 이착륙기와 같은 비행체의 정지비행 도중 비행체의 위치각, 각속도, 각가속도와 같은 상태량을 궤환 시킨 SRFIMF(State Rate Feedback Implicit Model-Following)이론을 이용하여 4개의 팬을 갖는 부상제어시스템을 구성하였다. 이 부상제어시스템의 yaw제어를 행하여, 각 상태궤환이득 및 전향경로 이득을 변화시켜 부상제어시스템의 특정을 해석하였으며, 부상시스템과 같은 제어계에 SRFIMF방식을 적용시켜 그 타당성을 조사하였다.

• 전자공학회논문지D
• /
• 제34D권5호
• /
• pp.7-13
• /
• 1997

A X-band 3-stage monolithic LNA (low noise amplifier) with series feedback has been successfully desined and demonstrated by suign 0.5-$\mu\textrm{m}$ GaAs MESFET. In the design of the 3-stage LNA, the effects of series feedback to the noise figure, the gain, and the stability have been investigated ot find the optimal short stub length. As a result, the inductive series feedback topology which has 10degree short stub in the GaAs MESFET source lead, has been employed in the 1-st stage. The fabricated MMIC LNA's chip size is only 1mm$^{2}$/stage, which is smaller than the previously reported X-band MMIC input/output return losses are less than -10dB and -15dB, respectively. The noise figure (NF) is less than 2.6dB. The measured data show good agreement with the simulated values.

• International Journal of Internet, Broadcasting and Communication
• /
• 제9권1호
• /
• pp.1-8
• /
• 2017

Nowadays many articles describe the controlling models for four rotor flying vehicle. Basic approaches to the problem of these articles are mathematical expressions describing dynamics of the models of the vehicle and PID control for manipulating the object in 3 dimensional space. Design of control systems is usually started by careful consideration of its mathematical model description. We present a detailed mathematical model for a quad rotor. This paper first considers simulation of quadcopter control based on full state feedback technique with linearization in MATLAB environment and shows the results of the simulations. Finally will be shown experimental results of the state feedback control implemented in real model.