• 제목/요약/키워드: PI algorithm

검색결과 549건 처리시간 0.025초

STR을 이용한 가솔린 엔진의 공연비 제어 성능 향상에 관한 연구 (A Study on the Improvement of Air-Fuel Ratio Control Performance in Sl Engine Using STR)

  • 신규철;박승범;윤팔주;정남훈;선우명호
    • 한국자동차공학회논문집
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    • 제9권6호
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    • pp.57-64
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    • 2001
  • This study presents an self tuning regulator(STR) to improve the air-fuel ratio control of performance of gasoline engine. The STR is designed based on the nonlinear dynamic engine model, and the performance of the STR is evaluated through the simulation and experiments. The STR shows better performance than a conventional PI controller in terms of the response time and disturbance rejection. Since the STR has less calculation load than the complex nonlinear controller, this algorithm can be easily applied to on-board engine controller.

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Effective Biological Sequence Alignment Method using Divide Approach

  • 최해원;김상진;피수영
    • 한국산업정보학회논문지
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    • 제17권6호
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    • pp.41-50
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    • 2012
  • This paper presents a new sequence alignment method using the divide approach, which solves the problem by decomposing sequence alignment into several sub-alignments with respect to exact matching subsequences. Exact matching subsequences in the proposed method are bounded on the generalized suffix tree of two sequences, such as protein domain length more than 7 and less than 7. Experiment results show that protein sequence pairs chosen in PFAM database can be aligned using this method. In addition, this method reduces the time about 15% and space of the conventional dynamic programming approach. And the sequences were classified with 94% of accuracy.

공간전압벡터 PWM을 이용한 영구자석형 동기전동기의 서보제어 시스템 (Servo Control System of Permanent Magnet Synchronous Motor Using Space Voltage Vector PWM)

  • 원의연;나상훈;윤덕용;홍순찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.290-293
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    • 1994
  • This paper proposes a servo control system of SPMSM (Surface-mounted Permanent Magnet Synchronous Motor) which essentially uses vector control method. The control system is composed of the PI controller for speed control and the current controller using space voltage vector PWM technique. The high-speed processing of algorithm for vector control and inverter switching for PWM is carried out by TMS320C31 DSP and IGBT module, respectively. The proposed scheme for 2.2kW SPMSM is verified through digital simulations and experiments, which show higher performance than that of traditional hysteresis current control technique.

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네트워크 최적화 기법에 의한 고압지중배전계통 계획 (A Planning on the high voltage underground distribution line using optimization technique)

  • 최상봉;김대경;정성환;김병숙
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 D
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    • pp.1044-1047
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    • 1997
  • This paper presents development of practical and universal program that is applied to ${\pi}$ loop system which is based on basic algorithm of network optimization for reduction investment cost and rationalization of underground plan. This system is ease to input and modify about information of powerline drawing, that is, can input easily condition of their calculation referring to candidate of underground apparatus under using digitizer.

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Wavelet Neural Network Controller for AQM in a TCP Network: Adaptive Learning Rates Approach

  • Kim, Jae-Man;Park, Jin-Bae;Choi, Yoon-Ho
    • International Journal of Control, Automation, and Systems
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    • 제6권4호
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    • pp.526-533
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    • 2008
  • We propose a wavelet neural network (WNN) control method for active queue management (AQM) in an end-to-end TCP network, which is trained by adaptive learning rates (ALRs). In the TCP network, AQM is important to regulate the queue length by passing or dropping the packets at the intermediate routers. RED, PI, and PID algorithms have been used for AQM. But these algorithms show weaknesses in the detection and control of congestion under dynamically changing network situations. In our method, the WNN controller using ALRs is designed to overcome these problems. It adaptively controls the dropping probability of the packets and is trained by gradient-descent algorithm. We apply Lyapunov theorem to verify the stability of the WNN controller using ALRs. Simulations are carried out to demonstrate the effectiveness of the proposed method.

A Wideband Interferometric Wavelength Shift Demodulator of Fiber Bragg Grating Strain Sensor

  • Song, Min-Ho
    • Journal of the Optical Society of Korea
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    • 제3권2호
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    • pp.64-68
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    • 1999
  • The performance of a fiber Bragg grating strain sensor constructed with 3$\times$3 coupler is investigated. A 3$\times$3 coupler Mach-Zehnder (M/Z) interferometer is used as wavelength discriminator, interrogating strain-induced Bragg wavelength shifts. Two quadrature-phase-shifted intensities are synthesized from the as-coupled interferometer outputs, and digital arctangent demodulation and phase unwrapping algorithm are applied to extract the phase information proportional to strain. Due to the linear relation between the input strain and the output of quadrature signal processing, signal-fading problems eliminated. In the experiment, a fiber grating that was surface adhered on an aluminum beam was strained in different ways, and the photodetector signals were transferred and processed in a computer-controlled processing unit. A phase recovery fo 7.8$\pi$ pk-pk excursion, which corresponds to ~650$\mu$strain pk-pk of applied strain, was demonstrated. The sensor system was stable over the environmental intensi쇼 perturbations because of the self-referencing effect in the demodulation process.

라즈베리 파이를 이용한 OpenCV 기반 CMT 알고리즘의 객체 추적 기법 (An Object Tracking Technique on OpenCV-based CMT Algorithm Using Raspberry Pi)

  • 송기범;양용준;이상구
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2017년도 추계학술발표대회
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    • pp.895-898
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    • 2017
  • 동영상 플랫폼 확산에 따라 영상 콘텐츠 수요와 공급이 폭발적으로 성장하여 영상 콘텐츠 확산에 큰 영향을 미치고 있다. 이와 같은 콘텐츠 확산으로 인해 전문가의 영역에 해당하는 영상 제작 기술이 일반적인 기술의 범주로 인식될 만큼 영상 처리 및 제작에 대한 기술의 발전이 나날이 급증하고 있으며 이러한 기술의 발전에 따라 사람의 수작업을 통해서만 영상을 조절하던 과정 또한 객체 추적 기술을 활용함에 따라 자동화 과정이 가능하게 되었다. 본 연구에서는 객체 추적 알고리즘 중 특징 점을 키포인트로 나눠 객체를 추적하는 OpenCV 기반 CMT 알고리즘으로 라즈베리파이를 활용하여 객체를 추적하는 기법을 소개한다. 본 시스템은 방송용 카메라의 객체 추적에 잘 활용될 수 있다.

게인 스케쥴링과 캐스케이드 제어에 의한 가상현실용 열환경의 실시간 구현 (Implementation of Real-Time Thermal Environment for Virtual Reality Using Gain Scheduling and Cascade Control)

  • 신영기;장영수;김영일
    • 제어로봇시스템학회논문지
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    • 제7권7호
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    • pp.567-573
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    • 2001
  • A real-time HVAC system is proposed which implements real-time control of thermal environment for virtual reality. It consists of a pair of hot and cold loops that serve as thermal reservoirs, and a mixing box to mix hot and cold air streams flowing if from loops. Their flow rates are controlled in real-time to meet a set temperature and flow rate. A cascade control algorithm along with gain scheduling is applied to the system and test results shows that the closed-loop response approached set values within 3 to 4 seconds.

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슬라이딩 모드 기반의 가변이득을 가지는 직접전력제어를 이용한 계통연계형 인버터의 성능개선 (Performance Improvement of a Grid-Connected Inverter System using a Sliding-Mode Based Direct Power Control with a Variable Gain)

  • 이병섭;이준석;이교범
    • 전력전자학회논문지
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    • 제17권1호
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    • pp.57-66
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    • 2012
  • This paper proposes a performance improvement of grid-connected inverter system using sliding-mode based direct power control with a variable gain. The proposed control method determine variable gain of PI controller by using modeling at direct power control (DPC) applied to space vector modulation method. Also, this method use sliding-mode control to maintain excellent dynamic response of character of direct power control (DPC). The validity of the proposed algorithm are verified by simulations and experiments.

개선된 퍼미언스법에 의한 영구자석 회전기의 해석 및 설계 (Analysis and Design of Permanent Magnet Motor by the Improved Permeance Method)

  • 정태경;오승석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.175-178
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    • 1998
  • To analyze and design a motor magnetic permeance method and numerical methods such as F.E.M. are used. In this thesis, DC motor is analyzed and designed by the permeance method. Modified Carter coefficient and leakage permeance are presented. A magnetic flux path can be approximated properly by using a equivalent ${\pi}$ network representation adding the leakage coefficient. Finally, effective and easy-to-use program is realized. Experimental analysis and design with an actual motor proves that this program produces reliable results. There are many experimental coefficients in this algorithm and it makes some design errors. Using of this program, an motor engineer can obtain satisfactory characteristic and design value by inputting initial data at once.

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