• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.2177-2178
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• 2011

In this paper, adaptive speed sensorless vector control, sliding mode observer to be present. Adaptive sliding mode observer of the motor stator coordinate system using the voltage equations of the rotor flux components are observed. Lyapunov function of the induction motor speed is estimated by the relationship further. In order to establish such a control scheme based on the way conventional PI controller and sliding mode observer annexing characteristics of the system through simulation and experiment were compared. Analyzed and compared according to the results presented confirmed the usefulness of the system.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2393-2405
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• 2015

This paper considers a decentralized multiple faults detection and isolation (FDI) scheme for reconfigurable manipulators. Inspired by their modularization property, a global sliding mode (GSM) based stable adaptive fuzzy decentralized controller is investigated for the system in fault free, while for the system suffering from multiple faults (actuator fault and sensor fault), the decentralized sliding mode observer (DSMO) is employed to detect their occurrence. Hereafter, the time and location of faults can be determined by a fault isolation scheme via a bank of DSMOs. Finally, the effectiveness of the proposed schemes in controlling, detecting and isolating faults is illustrated by the simulations of two 3-DOF reconfigurable manipulators with different configurations successfully.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1154-1156
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• 2001

This paper presents the implementation of a positon sensorless vector control system of a PM linear synchronous motor by sliding mode observer based on TMS320F240 DSP controller. Sliding mode observer estimates the secondary velocity and position based on the measurement of current, and it shows very robust characteristic to parameter variation. Therefore, it improves the system performance deterioration caused by system parameter variations. Simulation and experimental considerations are presented to confirm the applicability of sliding mode observer to the sensorless position control of PMLSM.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.119-121
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• 2005

The sliding-mode control technique could make a system unstable which external disturbance and uncertainty exists in. This paper suggests a robust sliding-mode control algorithm which can be applied to a linear system with parameter uncertainties. To reduce the chattering effect, the whole system is comprised of using a state variable in which the state's estimated value is added. The condition of estimated state results from state observer. The proposed control algorithm uses the optimal feedback controller following the dynamic system equation which consists of a state variable resulting from its own state variable, controller input, estimated state variable. Through comparison with the time optimal control algorithm using simulation, the suggested algorithm shows the improved stability and robustness while it manifests the fast tracking characteristics.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.851-857
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• 2019

A new robust sliding mode control with disturbance and state observers has been proposed to control the nozzle angle of a water-jet system for a Unmanned Surface Vehicle (USV). As the water-jet system of a ship is subjected to direct disturbances owing to the exposure to the marine environment in water, it requires a robust control. A state observer and a disturbance observer are added to the water jet nozzle control system to achieve a robust control against disturbances. To verify the performance of the proposed algorithm, a test bed is constructed by a propulsion system used in the popular USV. This proposed algorithm has been evaluated by comparing to the existing algorithm through experiments. The results show that the performance of the proposed algorithm is better than that of the conventional PID or sliding mode controller when controlling the steering of the USV with disturbances.

• 한국항행학회논문지
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• 제10권3호
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• pp.191-197
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• 2006

본 논문에서는 적응 속도 관측기를 사용한 유도전동기의 센서리스 슬라이딩 모드 제어 방법을 제안하였다. 제어 목적은 엔코더를 대신하여 적응 속도 관측기를 적용하고, 전류 제어기에 포함된 파라미터 변화와 외란으로 인한 오차를 슬라이딩 모드 전류 제어기를 사용하여 제거하는 것이다. 제어 시스템에 적용된 슬라이딩 모드 전류 제어기와 적응 속도 관측기의 안정도는 Lyapunov 안정도 판별법을 이용하여 해석하였다. 제안한 제어 시스템의 성능은 Matlab Simulink를 사용한 모의 실험으로 증명되며, 유도전동기를 사용한 실험 결과를 통하여 실현 가능성을 확인하였다.

• Journal of Power Electronics
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• 제18권6호
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• pp.1708-1719
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• 2018

A complete current loop decoupling control strategy based on a sliding mode observer (SMO) is proposed to eliminate the influence of current dynamic coupling and back electromotive force (EMF) in the vector control of permanent magnet synchronous motors. With this strategy, current dynamic decoupling and back EMF compensation can be simultaneously achieved. Unlike conventional methods, the proposed strategy can avoid the disturbances caused by the parametric variations of motor systems and maintain the advantages of proportional integral (PI) controllers, which are robust and easy to operate. An improved SMO, which uses a special PI regulator other than a linear saturation function as the equivalent control law in the boundary layer of a sliding surface, is proposed to eliminate the estimated errors caused by the quasi-sliding mode and obtain a satisfactory decoupling performance. The stability and parameter robustness of the proposed strategy are also analyzed. Physical experimental results are presented to verify the validity of the method.

• International Journal of Aeronautical and Space Sciences
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• 제4권1호
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• pp.1-8
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• 2003

In this paper, a reconfigurable flight control system is designed by applying the sliding mode control scheme. The sliding mode control method is a nonlinear control method which has been widely used because of its merits such as robustness and flexibility. In the sliding mode controller design, the signum function is usually included, but it causes the undesirable chattering problem. The chattering phenomenon can be avoided by using the saturation function instead of signum function. However, the boundary layer of the sliding surface should be carefully treated because of the use of the saturation function. In contrast to the conventional approaches, the thickness of the boundary layer of our approach does not need to be small. The reachability to the boundary layer is guaranteed by the sliding mode controller. The fault detection and isolation process is operated based on a sliding mode observer. To evaluate the reconfiguration performance, a numerical simulation using six degree-of-freedom aircraft dynamics is performed.

• 드라이브 ㆍ 컨트롤
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• 제14권2호
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• pp.30-36
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• 2017

This paper presents a sliding mode observer-based fault detection algorithm for steering inputs of an all-terrain crane. All-terrain cranes with multi-axles have several steering modes for various working purposes. Since steering angles at the other axles except the first wheel are controlled by using the information of steering angle at the first wheel, a reliable signal of the first axle's steering angle should be secured for the driving safety of cranes. For the fault detection of steering input signal, a simplified crane model-based sliding mode observer has been used. Using a sliding mode observer with an equivalent output injection signal that represents an actual fault signal, a fault signal in steering input was reconstructed. The road steering mode of the crane's steering system was used to conduct performance evaluations of a proposed algorithm, and an arbitrary fault signal was applied to the steering angle at the first wheel. Since the road steering mode has different steering strategies according to different speed intervals, performance evaluations were conducted based on the curved path scenario with various speed conditions. The design of algorithms and performance evaluations were conducted on Matlab/Simulink environment, and evaluation results reveal that the proposed algorithm is capable of detecting and reconstructing a fault signal reasonably well.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.284-284
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• 2000

In adaptive fuzzy control systems. fuzzy systems are used to approximate the unknown plant nonlinearities. Until now. most of the papers in the field of controller design for nonlinear system using fuzzy systems considers the affine system with fixed grid-rule structure based on system state availability. This paper considers observer-based nonlinear controller and dynamic fuzzy rule structure. Adaptive laws for fuzzy parameters for state observer and fuzzy rule structure are established so that the whole system is stable in the sense of Lyapunov.