• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2143-2145
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• 2002

This paper proposes the control problem of an inverted pendulum system based on adaptive fuzzy sliding mode. The universal approximating capability, learning ability, adaptation capability and disturbance rejection are collected in one control strategy. The proposed scheme does not require an accurate dynamic model and the joint acceleration measurement, yet it guarantees asymptotic trajectory tracking. Experimental results perform with an inverted pendulum to show the effectiveness of the approach.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.221-222
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• 2007

본 논문에서는 초정밀 위치 결정 시스템에서 보다 정확한 제어를 위한 새로운 제어기를 설계한다. 외란을 고려한 시스템의 경우, 환경이 달라질 때마다 측정 노이즈를 정확하게 알아내기란 쉽지 않다. 따라서 측정 장치의 정확성을 나타낼 수 있도록 칼만 필터추정기와 퍼지 이론을 이용하여 정확한 측정 오차값을 구한다. 이때, 파라미터 불확실성과 의란에 강인한 제어를 위해 슬라이딩 모드 제어기와 LQ 최적 제어기가 적용된다. 최종적으로, 제안된 제어기와 시간 최적 제어기의 성능비교를 통하여 보다 강인하고 안정된 성능개선을 증명한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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• pp.131-134
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• 2002

일반적인 산업현장에서 많이 사용되는 이중탱크 시스템은 동작점 근방에서 선형화하는 고전제어기법을 사용한 것으로서 큰 시간지연과 비선형성으로 인해 정확한 수학적 모델링이 어렵고 모델링을 하더라도 넓은 동작 영역에서 만족스로운 결과를 얻기 어렵다. 따라서, 비교적 모델링에 대한 의존도가 낮은 퍼지, 신경회로망, 유전알고리즘 등의 지능제어 기법들도 제안되고 있다. 그러나 이들 제어기 역시 외란이나 다양한 동작 모드들에 따른 제어기 변수들의 적응성 저하로 인해 안정화 가능 영역이 협소해 지는 것은 물론 시스템의 불안정 현상도 초래한다. 이에 반해, SMC(sliding mode controller)는 변수의 변동, 외란에 둔감한 강점을 갖고 있지만, 시스템의 상태에 따른 슬라이딩 평면 설정의 곤란성과 채터링(chattering)이 존재하는 문제점 이 있다. 따라서 본 논문에서는 이중 탱크 시스템의 정밀한 수위 제어를 위하여, GA과 FLC를 사용하여 최적 변수로 설정 할 수 있게 하고, 채터링 저감을 위해 시스템 동특성 변동과 외란 에 강인한 GA-FSMC(genetic algorithm fuzzy sliding mode controller)를 제안하였다. 시뮬레이션을 통해 종래의 제어기의 제어결과와 비교함으로써 제안하는 GA-FSMC의 우수성을 입증하고자 한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 추계학술대회
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• pp.259-260
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• 2010

This paper presents the sensorless and MPPT control algorithm for a 100kW tidal energy system. The proposed algoritm is estimated the rotor position and generator speed using adaptive sliding mode observer. The vector control of generator at the machine side converter and the converter at the grid side are controlled to obtain maximum torque and to regulate unity power factor respectively. Psim simulation is used for validity of proposed control algorism.

• 제어로봇시스템학회논문지
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• 제8권9호
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• pp.719-727
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• 2002

We proposed a decoupled adaptive fuzzy sliding-mode control scheme for a class of fourth-order nonlinear systems. The system is decoupled into two second-order systems such that each subsystem has a separate control target expressed in terms of sliding surface. For these sliding surfaces, we define main and sub target conditions. and, we made intermediate variables which are interconnected both surface conditions from the sub target sliding surface. Then, Two sets of fuzzy rule bases are utilized to represent the equivalent control input with unknown system functions of the main target sliding surface including intermediate variables. The membership functions of the THEN-part, which is used to construct a suitable equivalent control of sliding-mode control, are changed according to the adaptive law. With such a design scheme, we not only maintain the distribution of membership functions over state space but also reduce the computing time considerably. We apply the decoupled adaptive sliding-mode control to a nonlinear Cart-Pole system and confirms the validity of the proposed approach.

• 제어로봇시스템학회논문지
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• 제18권6호
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• pp.555-561
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• 2012

This paper describes the design of a fuzzy adaptive sliding mode controller for tracking control of robotic manipulators. The proposed controller incorporates a modified traditional sliding mode controller to drive the system state to a sliding surface and then keep the system state on this surface, and a fuzzy logic controller to accelerate the reaching phase. The stability of the control system is ensured by using Lyapunov theory. To verify the effectiveness of the proposed controller, computer simulation is conducted for a five-bar planar robotic manipulator. The simulation results show that the proposed controller can improve the reaching time and eliminate chattering of the control system at the same time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.902-906
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• 2008

The linear motors are easily affected by load disturbance, force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbance. For highspeed/high-accuracy position control of a linear-motor-driven two axes, a nonlinear adaptive controller including a cross-coupling algorithm is designed in this paper. The nonlinear effects such as friction and force ripple are estimated and compensated. An enhanced approach for cross-coupling algorithm is proposed to effectively improve the biaxial contour accuracy with the closed-loop stability. The proposed controller is evaluated through the computer simulations.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.91-96
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• 2001

This paper presents a neural net based nonlinear adaptive controller for an autonomous underwater vehicle (AUV). AUV's dynamics are highly nonlinear and their hydrodynamic coefficients vary with different operational conditions, so it is necessary for the high performance control system of an AUV to have the capacities of learning and adapting to the change of the AUV's dynamics. In this paper a linearly parameterized neural network is used to approximate the uncertainties of the AUV's dynamics, and a sliding mode control is introduced to attenuate the effects of the neural network's reconstruction errors and the disturbances of AUV's dynamics. The presented controller is consist of three parallel schemes; linear feedback control, sliding mode control and neural network. Lyapunov theory is used to guarantee the asymptotic convergence of trajectory tracking errors and the neural network's weights errors. Numerical simulations for motion control of an AUV are performed to illustrate to effectiveness of the proposed techniques.

• 한국해양공학회지
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• 제16권1호
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• pp.8-15
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• 2002

This paper presents a neural net based nonlinear adaptive controller for an autonomous underwater vehicle (AUV). AUV's dynamics are highly nonlinear and their hydrodynamic coefficients vary with different operational conditions, so it is necessary for the high performance control system of an AUV to have the capacities of learning and adapting to the change of the AUV's dynamics. In this paper a linearly parameterized neural network is used to approximate the uncertainties of the AUV's dynamic, and the basis function vector of network is constructed according to th AUV's physical properties. A sliding mode control scheme is introduced to attenuate the effect of the neural network's reconstruction errors and the disturbances in AUV's dynamics. Using Lyapunov theory, the stability of the presented control system is guaranteed as well as the uniformly boundedness of tracking errors and neural network's weights estimation errors. Finally, numerical simulations for motion control of an AUV are performed to illustrate the effectiveness of the proposed techniques.

• 드라이브 ㆍ 컨트롤
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• 제14권4호
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• pp.37-44
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• 2017

This paper introduces a control algorithm for trajectory control of an electro-hydrostatic rotary actuator. A key feature of this paper is that an adaptive PID based on sliding mode is used to control the nonlinearity and uncertainty factor of single input/output system. Accurate knowledge of rotary actuator angle can result in high-performance and efficiency of electro hydraulic system. First, the position control is formulated using the adaptive PID with sliding mode technique and uncertainties in the hydraulic system. Second, the controller can update the PID gains on-line based on error caused by external disturbance and uncertain factors in the system. Finally, three experimental cases were studied to evaluate the proposed control method.