• 한국산학기술학회논문지
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• 제13권1호
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• pp.306-310
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• 2012

위치추정 서비스는 사물이나 사람의 위치를 추정하여 표현하는 것으로, 본 논문에서는 Zigbee를 지원하는 RF칩인 CC2420칩셋을 통한 네트워크 환경을 실외에 구축하고, 이동노드를 이용하여 GPS에서 얻어진 이동노드에 대 한 위치정보를 수신한다. 이동노드의 위치정보는 구축된 네트워크 환경에서 싱크노드에 전달함으로서 실시간으로 위치를 추정할수 있게 되며 실외환경에서 위치추정 오차는 3m 내에서 나타났으며 이는 육안으로 쉽게 판별가능한 범위이고 Google Maps을 이용하여 위치를 표현해 내었다.

• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.90-95
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• 2010

This paper describes the development of integrated head and eye tracker system. Vision based head tracker is performed and it has 7mm error in 300mm translation. The epi-polar method and point matching are used for determining a position of head and rotational degree. High brightness LEDs are installed on helmet and the installed pattern is very important to match the points of stereo system. Eye tracker also uses LED for constant illumination. A Position of gazed object(3m distance) is determined by pupil tracking and eye tracker has 1~5 pixel error. Integration of result data of each tracking system is important. RS-232C communication is applied to integrated system and triggering signal is used for synchronization.

• 전자공학회논문지SC
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• 제49권1호
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• pp.74-79
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• 2012

위상배열레이더를 이용한 추적의 성능을 지수화하기 위해서 각도예측 오차공분산행렬의 함수를 이용한 정량화 방법에 대해 검토하였다. 특히, 이 오차공분산행렬의 함수로 최대고유값과 대각합을 이용하여 정량화하는 경우에 대해 안테나 빔조향 손실을 반영한 표적탐지확률을 기준으로 정량화의 일관성을 수치실험을 통해 검토하였다. 이를 통해 추적성능을 표적탐지확률로 기준하는 경우, 대각합이 최대고유값 보다 더 일관성을 갖는 정량화 함수임을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2351-2353
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• 1998

This paper suggests the wheel controller for PWS(Power Wheeled Steering) mobile robot. The proposed controller consists of two parts. To control each motor, the sliding mode controller implemented. This method has robustness about modeling error and disturbance, so the velocity tracking is well guaranteed in the presence of varying load. The design of a fuzzy cross-coupling controller for a PWS mobile robot is described here. Fuzzy cross-coupling control directly minimizes the tracking error by coordinating the motion of the two drive wheels. The fuzzy cross-coupling controller has excellent disturbance rejection and therefore is advantageous when the robot is not loaded symmetrically. The capability of the proposed controller was verified through the computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.426-428
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• 1998

In this paper, a ramp tracking controller design method is proposed for the systems with nonlinear frictions. The objective is to design a controller which is capable of tracking a ramp reference input without steady state error. The controller is composed of a linear controller, integrators for error compensation, and a friction compensator. The compensator estimates the parameters of friction model. The friction parameters are estimated using two different method. Simulation and experimental results show that the proposed method is effective.

• 한국공작기계학회논문집
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• 제17권5호
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• pp.44-51
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• 2008

In this paper, the optimal tuning of a cross-coupled controller linked with the feedforward controller is studied to reduce contouring and tracking errors of a bi-axial servomechanisms by using the previously developed integrated tuning method. The CCC system for an arbitrary curve, which is combined with the feedforward controller, is formulated by a state-space based on a series of linear motion trajectories. An optimal tuning problem is formulated as a nonlinear constrained optimization problem including relevant controller parameters of the servo. To verify the effectiveness of the proposed optimal tuning procedure, linear and circular motion experiments are performed on the xy-table. Experimental results confirm that both tracking and contouring errors are significantly reduced by applying the proposed control and tuning system.

• 전기학회논문지
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• 제66권1호
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• pp.159-164
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• 2017

In this paper, we propose a method of designing the sampled-data tracking controller for nonlinear systems expressed by the Takagi-Sugeno (T-S) fuzzy model. A sufficient condition that asymptotically stabilizes the state error between the linear reference model and the T-S fuzzy model is derived in terms of linear matrix inequalities. To this end, error dynamics are constructed, and the exact discretization method and the Lyapunov stability theory are employed in this paper. Finally, we validate the proposed method through the simulation example.

• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.77-82
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• 2010

무선주파수를 사용하는 추적안테나의 추적성능은 비행체 추적 및 위치 측정에서 매우 중요한 요소이나, 전기적 물리적으로 매우 큰 안테나의 특성을 정확히 측정하는 것은 쉽지 않다. 특히 우주응용분야에서 사용되는 대형 접시형 추적안테나 시스템과 같이 신호원을 따라 안테나의 지향방향이 변하는 경우에는 안테나 지향방향에 따라 특성이 일정하지 않을 수 있다. 본 논문에서는 대형 추적안테나 시스템의 추적 성능지표인 지향정확도 및 추적정확도에 영향을 주는 오차요인을 검토하고, 나로우주센터에서 원격측정용으로 사용하고 있는 11m 대형 접시형 추적안테나에 대한 추적성능을 효율적으로 측정할 수 있는 저궤도위성(Low Earth Orbit)을 사용한 측정방법 및 그 결과를 기술한다.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.668-673
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• 2010

Given a periodic reference signal or disturbance, repetitive control is a special control scheme to reduce a tracking error effectively by the periodic signal generator in the repetitive controller. In general, a repetitive controller is added on the existing feedback control system to improve the tracking performance. However, because the information used in the design of the feedback controller is not taken into account, the design problem of the repetitive controller is totally another problem irrespective of that of the feedback controller. In this paper, we present a more general method to design an add-on type repetitive controller using the information on the performance of the existing feedback control system. We first show that a robust stability condition of repetitive control systems is obtained using the well-known robust performance condition of general feedback control systems. It is also shown that we can obtain a steady-state tracking error described in a simple form without time-delay element if the robust stability condition is satisfied for the repetitive control system. From the obtained results, several design criterions for repetitive controller are provided. Through the simulation study, the feasibility of the proposed method is verified.

• International Journal of Control, Automation, and Systems
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• 제6권2호
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• pp.269-277
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• 2008

This paper proposes a necessary and sufficient condition of convergence in the $L_2$-norm sense for a feedback-based iterative learning control (ILC) system including a multi-input multi-output (MIMO) linear time-invariant (LTI) plant. It is shown that the convergence conditions for a nominal plant and an uncertain plant are equal to the nominal performance condition and the robust performance condition in the feedback control theory, respectively. Moreover, no additional effort is required to design an iterative learning controller because the performance weighting matrix is used as an iterative learning controller. By proving that the least upper bound of the $L_2$-norm of the remaining tracking error is less than that of the initial tracking error, this paper shows that the iterative learning controller combined with the feedback controller is more effective to reduce the tracking error than only the feedback controller. The validity of the proposed method is verified through computer simulations.