• Title/Summary/Keyword: Model mismatch

Search Result 245, Processing Time 0.025 seconds

Design of Robust Controller for Systems with Time Delay (지연시간을 갖는 계통에 대한 강인한 제어기 설계)

  • 박귀태;이기상;김성호
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.39 no.9
    • /
    • pp.997-1005
    • /
    • 1990
  • Integral Error and State Feedback (IESF) controller which incorporates state feedback as a modern control scheme and integral action as a classical control scheme has better performance than that of conventional PID controller in linear time invariant system. But the structure of the IESF controller requires all the state variables of the system and is applicable only to pole assignable linear time invariant systems without time delay. Many industrial processes have large time delay and it is impossible to directly apply IESF control scheme to those processes. In this paper, a new controller structure, Modified Integral Error and State Feedback (MIESF) has been suggested in order to effectively control processes having time delay and its performance has been analyzed and its effectiveness has also been confirmed. As the proposed controller uses output feedback scheme based on integral error and state feedback (IESF) method, it can be simply designed by pole assignment algorithm irrespective of the order of the process. The MIESF controller can follow setpoint changes without overshoot. It is robuster than conventional Smith-Predictor plus PI(D) controller in case of occurring time delay mismatch and extra parameter mismatches between the process and the model. It can enhance control performance by intentional time delay mismatch.

  • PDF

Impact of Different Green-Ampt Model Parameters on the Distributed Rainfall-Runoff Model FLO-2D owing to Scale Heterogeneity (분포형 강우-유출 모형에서 토양도 격자크기 효과가 Green-Ampt 모형의 매개변수와 모의된 강우손실에 미치는 영향)

  • Hwang, Ji-hyeong;Lee, Khil-Ha
    • Journal of Environmental Science International
    • /
    • v.29 no.1
    • /
    • pp.15-23
    • /
    • 2020
  • The determination of soil characteristics is important in the simulation of rainfall runoff using a distributed FLO-2D model in catchment analysis. Digital maps acquired using remote sensing techniques have been widely used in modern hydrology. However, the determination of a representative parameter with spatial scaling mismatch is difficult. In this investigation, the FLO-2D rainfall-runoff model is utilized in the Yongdam catchment to test sensitivity based on three different methods (mosaic, arithmetic, and predominant) that describe soil surface characteristics in real systems. The results show that the mosaic method is costly, but provides a reasonably realistic description and exhibits superior performance compared to other methods in terms of both the amount and time to peak flow.

Design of IMC Controller for Nonlinear Systems by Using Adaptive Neuro-Fuzzy Inference System (뉴로 퍼지 시스템을 이용한 비선형 시스템의 IMC 제어기 설계)

  • 강정규;김정수;김성호
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.236-236
    • /
    • 2000
  • Control of Industrial processes is very difficult due to nonlinear dynamics, effect of disturbances and modeling errors. M.Morari proposed Internal Model Control(IMC) system that can be effectively applied to the systems with model uncertainties and time delays. The advantage of IMC systems is their robustness with respect to a model mismatch and disturbances. But it was difficult to apply for nonlinear systems. Adaptive Neuro-Fuzzy Inference System which contains multiple linear models as consequent part is used to model nonlinear systems. Generally, the linear parameters in neuro-fuzzy inference system can be effectively utilized to identify a nonlinear dynamical systems. In this paper, we propose new IMC design method using adaptive neuro-fuzzy inference system for nonlinear plant. Numerical simulation results show that proposed IMC design method has good performance than classical PID controller.

  • PDF

다축 공작기계의 위치정밀도 향상을 위한 추적제어기 설계

  • 서정환;양호석;이천환;이승욱;이건복
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1992.10a
    • /
    • pp.192-197
    • /
    • 1992
  • The position error in multi-axis machine tools are due to many elements, such as the static friction, servo lag, a nonlinear disturbance, the gain mismatch between multi-axis controllers. In the work, modeling for the plant was carried out through the velocity response by the step input signal. Digital PI controllers, LQ optimal controllers and feedforward controllers are designed for a high tracking performance based on the model. The results of experimentation showed that the controllers worked properly.

Frequency Response Analysis of Electrostatic Microactuators (정전형 마이크로 엑츄에이터의 주파수 응답 특성 해석)

  • Min, Dong-Ki
    • Proceedings of the KIEE Conference
    • /
    • 2002.07c
    • /
    • pp.1982-1984
    • /
    • 2002
  • The admittance of one-port electrostatic actuator are modeled using the steady-state sinusoidal response. Also the admittance of the differential type actuator is derived taking the practical conditions into consideration, although it has no admittance in ideal case. It is a function of biasing error, driving error, and capacitive mismatch including parasitic capacitors. The validity of the admittance model is proved by comparing between the modeled and measured admittances. The distortion in the frequency response curve measured by a capacitive sensor is analyzed and it is concluded that the admittance is the main cause of this distortion.

  • PDF

Robust Speed Control of Brushless DC Motor Using Adaptive Input-Output Linearization Technique (적응 입출력 선형화 기법을 이용한 Brushless DC Motor의 강인한 속도 제어)

  • 김경화;백인철;문건우;윤명중
    • Proceedings of the KIPE Conference
    • /
    • 1997.07a
    • /
    • pp.89-96
    • /
    • 1997
  • A robust speed control scheme for a brushless DC(BLDC) motor using an adaptive input-output linearization technique is presented. By using this technique, the nonlinear motor model can be linearized in Brunovski canonical form, and the desired speed dynamics can be obtained based on the linearized model. This control technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions. For the robust output response, the controller parameters will be estimated by a model reference adaptive technique where the disturbance torque and flux linkage are estimated. The adaptation laws are derived by the Popov's hyperstability theory and positivity concept. The proposed control scheme is implemented on a BLDC motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative experiments.

  • PDF

The Effect of Finite Element Models in Thermal Analysis of Electronic Packages (반도체 패키지의 열변형 해석 시 유한요소 모델의 영향)

  • Choi, Nam-Jin;Joo, Jin-Won
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.33 no.4
    • /
    • pp.380-387
    • /
    • 2009
  • The reliability concerns of solder interconnections in flip chip PBGA packages are produced mainly by the mismatch of coefficient of thermal expansion(CTE) between the module and PCB. Finite element analysis has been employed extensively to simulate thermal loading for solder joint reliability and deformation of packages in electronic packages. The objective of this paper is to study the thermo-mechanical behavior of FC-PBGA package assemblies subjected to temperature change, with an emphasis on the effect of the finite element model, material models and temperature conditions. Numerical results are compared with the experimental results by using $moir{\acute{e}}$ interferometry. Result shows that the bending displacements of the chip calculated by the finite element analysis with viscoplastic material model is in good agreement with those by $moir{\acute{e}}$ inteferometry.

Model-based Fault Diagnosis Applied to Vibration Data (진동데이터 적용 모델기반 이상진단)

  • Yang, Ji-Hyuk;Kwon, Oh-Kyu
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.18 no.12
    • /
    • pp.1090-1095
    • /
    • 2012
  • In this paper, we propose a model-based fault diagnosis method applied to vibration data. The fault detection is performed by comparing estimated parameters with normal parameters and deciding if the observed changes can be explained satisfactorily in terms of noise or undermodelling. The key feature of this method is that it accounts for the effects of noise and model mismatch. And we aslo design a classifier for the fault isolation by applying the multiclass SVM (Support Vector Machine) to the estimated parameters. The proposed fault detection and isolation methods are applied to an engine vibration data to show a good performance. The proposed fault detection method is compared with a signal-based fault detection method through a performance analysis.

Performance Improvement of SPLICE-based Noise Compensation for Robust Speech Recognition (강인한 음성인식을 위한 SPLICE 기반 잡음 보상의 성능향상)

  • Kim, Hyung-Soon;Kim, Doo-Hee
    • Speech Sciences
    • /
    • v.10 no.3
    • /
    • pp.263-277
    • /
    • 2003
  • One of major problems in speech recognition is performance degradation due to the mismatch between the training and test environments. Recently, Stereo-based Piecewise LInear Compensation for Environments (SPLICE), which is frame-based bias removal algorithm for cepstral enhancement using stereo training data and noisy speech model as a mixture of Gaussians, was proposed and showed good performance in noisy environments. In this paper, we propose several methods to improve the conventional SPLICE. First we apply Cepstral Mean Subtraction (CMS) as a preprocessor to SPLICE, instead of applying it as a postprocessor. Secondly, to compensate residual distortion after SPLICE processing, two-stage SPLICE is proposed. Thirdly we employ phonetic information for training SPLICE model. According to experiments on the Aurora 2 database, proposed method outperformed the conventional SPLICE and we achieved a 50% decrease in word error rate over the Aurora baseline system.

  • PDF

Adaptive Input-Output Linearization Technique for Robust Speed Control of Brushless DC Motor

  • Kim, Kyeong-Hwa;Baik, In-Cheol;Kim, Hyun-Soo;Youn, Myung-Joong
    • Journal of Electrical Engineering and information Science
    • /
    • v.2 no.3
    • /
    • pp.113-122
    • /
    • 1997
  • An adaptive input-output linearization technique for a robust speed control of a brushless C(BLDC) motor is presented. By using this technique, the nonlinear moro model can be effectively linearized in Brunovski canonical form, an the desired speed dynamics can be obtained based on the linearized model. This control technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions caused by the incomplete linearization. for the robust output response, the controller parameters will be estimated by a model reference adaptive technique where the disturbance torque and flux linkage are estimated. The adaptation laws are derived by the Popov's hyperstability theory nd positivity concept. The proposed control scheme is implemented on a BLDC motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative simualtions and experiments.

  • PDF