• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.222-226
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• 1992

In this study, the technique of adaptive control based on certainty equibalence for input-output linerization of nonlinear system is investigated. It is shown that the upper bound of the parameter estimation error can be represented more explicitly than Teel et al's works. Another direct approach, which shows that the adaptive input-output linearing control laws using the normalized identifier yield bounded tracking is also presented.

• 대한전자공학회논문지
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• 제25권9호
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• pp.1046-1050
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• 1988

A direct adaptive control algorithm for discrete-time SISO systems with arbitrary zeros is presented in a general way by making use of reference model. A linear equation error model is formulated for estimating both the controller parameters and the auxiliary parameters. With this algorithm, asyptotic tracking within an arbitrarily small error can be achieved.

• Journal of Power Electronics
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• 제4권1호
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• pp.1-11
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• 2004

A stable adaptive sensorless speed controller for three-level inverter fed induction motor direct torque control (DTC) system using the radial-basis function network (RBFN) is presented in this paper. Torque ripple in the DTC system for high power induction motor could be drastically reduced with the foregoing researches of switching voltage selection and torque ripple reduction algorithms. However, speed control performance is still influenced by the inherent uncertainty of the system such as parametric uncertainty, external load disturbances and unmodeled dynamics, and its exact mathematical model is much difficult to be obtained due to their strong nonlinearity. In this paper, the inherent uncertainty is approximated on-line by the RBFN, and an additional robust control term is introduced to compensate for the reconstruction error of the RBFN instead of the rich number of rules and additional updated parameters. Control law for stabilizing the system and adaptive laws for updating both of weights in the RBFN and a bounding constant are established so that the whole closed-loop system is stable in the sense of Lyapunov, and the stability proof of the whole control system is presented. Computer simulations as well as experimental results are presented to show the validity and effectiveness of the proposed system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권7호
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• pp.399-405
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• 2002

This paper presents an implementation of digital high-performance Position sensorless motion control system of an induction motor drives with Direct Torque Control(DTC). The system consist of closed loop stator flux and torque observer, speed and torque estimators, two hysteresis controller, optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP board. The stator flux observer is based on the combined current and voltage model with stator flux feedback adaptive control of which inputs are current and voltage sensed on motor terminal for wide speed range. The speed observer is using the model reference adaptive system(MRAS) with rotor flux linkages for speed turning signal. The simulation and experimental results are provided to evacuate the consistency and the performance of the suggested position sensorless control algorithm. The developed position sensorless system are shown a good motion control response characteristic and high performance features using 2.2[kw] general purposed induction motor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.80.2-80
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• 2002

The problem of sound source localization is to determine the position of sound sources using the measurement of the acoustic signals received by microphones. To develop a good sound source localization system which is applicable to a mobile platform such as robots, a time delay estimator with low computational complexity and robustness to background noise or reverberations is necessary. In this paper, an explicit adaptive time delay estimation method for a sound source localization system is proposed. Proposed explicit adaptive time estimation algorithm employs direct adaptation of the delay parameter using a transform-based optimization technique, rather than...

• 자동차안전학회지
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• 제12권4호
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• pp.13-22
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• 2020

This paper presents an adaptive feedback based actuator fault detection and tolerant control algorithms for longitudinal functional safety of autonomous driving. In order to ensure the functional safety of autonomous vehicles, fault detection and tolerant control algorithms are needed for sensors and actuators used for autonomous driving. In this study, adaptive feedback control algorithm to compute the longitudinal acceleration for autonomous driving has been developed based on relationship function using states. The relationship function has been designed using feedback gains and error states for adaptation rule design. The coefficients in the relationship function have been estimated using recursive least square with multiple forgetting factors. The MIT rule has been adopted to design the adaptation rule for feedback gains online. The stability analysis has been conducted based on Lyapunov direct method. The longitudinal acceleration computed by adaptive control algorithm has been compared to the actual acceleration for fault detection of actuators used for longitudinal autonomous driving.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권1호
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• pp.38-44
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• 2001

This paper investigates the direct adaptive control of nonlinear systems using RBFN(radial basis function networks). The structure of the controller consists of a fixed PD controller and a RBFN controller in parallel. An adaptation law for the parameters of RBFN is developed based on the Lyapunov stability theory to guarantee the stability of the overall control system. The filtered tracking error between the system output and the desired output is shown to be UUB(uniformly ultimately bounded). To evaluate the performance of the controller, the proposed method is applied to the trajectory contro of the two-link manipulator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.978-980
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• 2000

Sensorless PMSM is much studied for the industrial applications and home appliances because, a mechanical sensor reduces reliability and increases cost. Two types of instantaneous torque controls are basically used for high performance variable-speed a.c. drive : vector control and direct torque control. This paper investigates speed sensorless control of PMSM using direct torque control. The switching of inverter is determined from SVPWM realizing the command voltage which is obtained by flux error and measured current without d-q transformation. The rotor speed is estimated through adaptive observer with feedback loop. The simulation and experimental results indicate good performances.

• Journal of Electrical Engineering and information Science
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• 제1권1호
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• pp.39-44
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• 1996

In this paper, adaptive controller with switching action is designed for rigid body robot manipulators to ensure the uniform stability of the manipulator system without a priori knowledge of the unmodeled dynamics. It will be shown that the parameter estimates are bounded independent of the other closed-loop signals boundedness, and also shown that the tracking error belongs to the normalized error bound via mathematical analisys. The robustness and performance of the proposed adaptive controller is investigated for the two-link direct drive manipulator actuated by VRM(Variable Reluctance Motor).

• 한국통신학회논문지
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• 제10권5호
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• pp.258-265
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• 1985

이 論文은 SISO 離散時間 基準모델 適應制御시스템에 대한 設計問題를 다루었다. 基準모델과 未知시스템의 入·出力端에 狀態變數필터를 도입하므로서, 可用信號들로 구성된 아주 간단한 適應시스템을 구성할 수 있다. 未知시스템의 相對次數가 1 또는 2 이상인 경우의 設計法은 多數 발표되었으나, 構造가 매우 복잡하거나 設計理論이 일반화하지 못하였다. 본 論文에서는 相對次數가 2이상인 경우에 간단한 線型필터를 도입하므로서 適應構造를 간단히 구성할 수 있음을 證明하였다.