• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.405-413
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• 2006

본 논문에서는 비선형 동적 마찰 성분을 효과적으로 보상하고 적응적으로 제어함으로써 차세대 항만 자동화 이송시스템으로 주목받고 있는 LMTT(linear motor-based transfer technology)의 위치 정밀도를 향상시키는 것을 목적으로 하고 있다. 셔틀카(shuttle car)와 컨테이너들의 다양한 중량과, 이로 인해 발생하는 동적 마찰 특성 파라미터들을 정확하게 추정할 수 있는 관측기를 설계하였다. 적응 backstepping 제어 기법을 적용하여 시스템이 안정하게 제어될 수 있도록 하는 제어기를 설계하였다. 시스템은 변화하는 환경에 대하여 높은 적응성을 가질 수 있어 여러 종류의 부하는 물론 마찰 특성의 변화에도 양호한 제어 특성을 유지할 수 있었다. 제안한 제어시스템의 타당성을 보여주기 위해 축소된 형태의 LMTT 시뮬레이터를 제작하여, 이에 대해 시뮬레이션과 실험만을 수행하여 제안하는 방법의 타당성과 실현성을 입증하고자 하였다.

• 한국항해항만학회지
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• 제31권1호
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• pp.55-64
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• 2007

일반적으로 서보 제어 시스템에서 비선형 동적 특성을 갖는 마찰력은 제어기 성능에 악영향을 미친다. 특히, 선형으로 고려된 시스템에 제어기 이득을 잘 설계한다 하더라도 마찰 현상에 포함된 동적으로 변화하는 dead zone에 의한 정상상태 오차 및 리미트 사이클(limit Cycle) 등을 야기한다. 따라서, 본 논문에서는 비선형 동적 마찰 성분을 효과적으로 보상하고 적응적으로 제어함으로써 차세대 항만 자동화 이송시스템으로 주목받고 있는 LMTT(linear motor-based transfer technology) 시스템의 위치 정밀도를 향상시키는 것을 목적으로 하고 있다. 본 제어대상은 셔틀카(shuttle car)와 컨테이너들의 다양한 중량과, 이로 인해 발생하는 동적 마찰 특성 파라미터들의 변화가 발생하므로 마찰력 내부 파라미터들의 추정이 요구된다. 제안하는 방법은 적응 backstepping 제어 기법으로 시스템이 안정하게 제어될 수 있는 조건으로 내부 파라미터 추정기를 설계하여 비선형 동적 마찰력을 보상하도록 하였다.

• 대한음성학회지:말소리
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• 제52호
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• pp.121-132
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• 2004

This paper is aiming at real-time implementation of adaptive noise cancellation system using DSP processor. ACHARF algorithm, which guarantees stability and fast convergence by adaptive compensator, is used on this DSP system. For the experiments, TLV320AIC23 stereo CODEC of TI Inc. is used with TMS320C6413 DSP processor. Signals of primary input and reference input are obtained by two microphones. The primary input is the voice plus noise signal and the reference input is white noise or real noise. The experimental results show that ANC system using DSP processor with ACHARF is verified to be an effective speech enhancement method for various speech processing units.

• 제어로봇시스템학회논문지
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• 제7권1호
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• pp.1155-1161
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• 2001

We propose an adaptive nonlinear control algorithm for high precision tracking and stabilization of LOS(Line-of-Sight). The friction parameters of the LOS gimbal are estimated by off-line evolutionary strategy and the friction is compensated by estimated friction compensator. Especially, as the nonlinear control input in a small tracking error zone is enlarged by the nonlinear function, the steady state error is significantly reduced. The proposed algorithm is a direct adaptive control method based on the Lyapunov stability theory, and its convergence is guaranteed under the limited modeling error or torque disturbance. The performance of the pro-posed algorithm is verified by computer simulation on the LOS gimbal model of a moving vehicle.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.448-453
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• 2004

In this paper, an adaptive robust decentralized excitation control scheme is proposed to enhance the transient stability of a multi-machine power system. We employ a state model where the terminal voltage of each generator is regarded as part of the state. Using this state model, the proposed controller is obtained in two steps: firstly, a robust controller is designed for the nominal system with no interconnection terms; then an adaptive compensator is proposed to deal with those interconnection terms, whose upper bounds are estimated. The resulting adaptive scheme guarantees the practical stability of the closed-loop, and also the uniform ultimate boundedness in the presence of disturbances.

• Advances in aircraft and spacecraft science
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• 제7권5호
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• pp.459-473
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• 2020

The aircraft nose landing gear (NLG) can suffer of an unstable vibration called shimmy that is responsible of discomfort and of fatigue stress on the gear strut components. An adaptive controller is proposed in this paper to cope with the aforementioned problem. It is based on a method called Modified Simple Adaptive control (MSAC) which is able of governing the NLG motion by using a feedback signal that relies on just one output of the plant. The MSAC only asks for the passivity of the controlled plant. With this aim, a parallel feedforward compensator is employed in this work to let the system satisfies the almost strictly passivity (ASP) requirements. The nonlinear equations that govern the aircraft NLG shimmy vibration behavior are used to analyzed the controlled system transient response undergoing an initial disturbance and taking into account different taxiing speed values.

• 유공압시스템학회논문집
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• 제7권3호
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• pp.1-6
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• 2010

This paper deals with the issue of simple adaptive position control for a pump-controlled cylinder system. A fixed displacement pump is utilized instead of servo valve and its speed is controlled by AC motor. The whole control system is composed of a pair of interconnected subsystems, that is, a feedback control system and a feedforward control system. From experiments it is shown that position control using simple adaptive control can accomplish significant reduction in position tracking error comparing to a conventional PID control.

• 대한전기학회논문지
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• 제39권9호
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• pp.944-955
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• 1990

A high-performance robotic controller is proposed for uncertain robots by using an adaptive control method, which guarantees the boundedness of uncertain systems with partially known uncertainty bounds. In order to improve the tracking performance of the robotic controller, a linear compensator is introduced to the robotic system which has been linearized via a nonlinear feedback. The above adaptive method is then utilized to guarantee the ultimate boundedness of the tracking errors. The performance of the robotic controller is compared with that of the computed torque method by computer simulations under uncertain environments. The simulation results show that the proposed method gives better performance than the computed torque method. Since the proposed method has a small number of parameters to be estimated, the controller is simpler to implement than other existing adaptive controller for robots. Hence, the proposed robotic control method is expected to be well suited for high-performance operation of robots under uncertain environment.

• International Journal of Control, Automation, and Systems
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• 제5권3호
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• pp.343-348
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• 2007

This paper presents an adaptive controller for the compensation of state-dependent disturbance with unknown amplitude in a digital servo motor system. The state-dependent disturbance is caused by friction and eccentricity between the wheel axis and the motor driver of a mobile robot servo system. The proposed control scheme guarantees an asymptotical stability for both the velocity and position regulation. An experimental result shows the effectiveness of the adaptive disturbance compensator for wheeled-mobile robot in a low velocity diffusion tracking. A comparative experimental study with a simple PI controller is presented.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권7호
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• pp.428-436
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• 2005

In this paper, we introduce an adaptive control method to improve the position accuracy and reduce nonlinear friction effects for the linear motion servo system with the nonlinear friction. The considered system plant included not only the variation of the mass of mover but also the friction change by the normal force. We also designed an adaptive controller with the mass estimator and the compensator by observing the variation of normal force. The effectiveness and system performances for the proposed control method in this paper show to improve than other control methods through numerical simulations.