• International Journal of Automotive Technology
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• 제3권4호
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• pp.165-170
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• 2002

For a vehicle Anti-lock Braking System (ABS), the control target is to maintain friction coefficients within maximum range to ensure minimum stopping distance and vehicle stability. But in order to achieve a directionally stable maneuver, tire side forces must be considered along with the braking friction. Focusing on combined braking and turning operation conditions, this paper presents a new control scheme for an ABS controller design, which calculates optimal target wheel slip ratio on-line based on vehicle dynamic states and prevailing road condition. A fuzzy logic approach is applied to maintain the optimal target slip ratio so that the best compromise between braking deceleration, stopping distance and direction stability performances can be obtained for the vehicle. The scheme is implemented using an 8-DOF nonlinear vehicle model and simulation tests were carried out in different conditions. The simulation results show that the proposed scheme is robust and effective. Compared with a fixed-slip ratio scheme, the stopping distance can be decreased with satisfactory directional control performance meanwhile.

• 한국지능시스템학회논문지
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• 제12권6호
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• pp.497-502
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• 2002

기동표적의 추적문제는 상태추정의 분야에서 수 십 년에 걸쳐 연구되어 왔다. 칼만 필터는 표적의 상태를 추정하기 위해 널리 사용되어 왔으나, 기동이 발생할 경우, 그 성능은 현저히 저하될 수 있다. 본 논문에서는 이러한 문제점을 해결하고, 기동표적을 효과적으로 추적하기 위해, DNA 코딩에 기반한 상호작용 다중모델 기법을 제안한다. 제안된 기법은 DNA 코딩에 기반한 퍼지 논리를 이용함으로써, 기존의 기법들의 수학적 한계를 극복할 수 있다. 컴퓨터 모의실험을 통하여, 제안된 기법의 추적 성능은 적응 상호작용 다중모델 기법 및 유전 알고리즘 기반 상호작용 다중모델 기법과 비교된다.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2004년도 제29회 추계학술대회 발표논문집
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• pp.140-143
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• 2004

To appropriately control or compensate breathing motion of targets in thorax or abdomen during radiotherapy is still demanding. Our idea is that a visual signal may help regulate patient's breathing pattern, by controlling its amplitude and cycle. The system involving breathing control with a visual signal for aperture maneuver with controlled breath (AMC) has been developed. A thermocouple is used to detect the temperature change due to patient's breathing. The system also consists of a mask, in which the thermocouple is installed, an operational amplifier, a converter, etc. Patients were instructed to control their respiration by breathing following the visuals signal, as watching a display that shows both patients' current breathing pattern and the signal. The patterns of patients' controlled breathing and the signals coincided well. Therefore, when AMC technique is applied, a target moves in the range that is 60 % less than the range of free breathing motion with the help of the system and so target margins can be reduced significantly. This study reveals that a visual signal is not only useful to control patient's breathing but also clinically effective.

• 한국정보통신학회논문지
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• 제26권9호
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• pp.1312-1319
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• 2022

본 논문은 미지 우주물체에 대한 광학 연속 관측을 위한 효과 척도를 정의하고, 통합 시뮬레이션 수행을 이용하여 망원경/마운트 제어 시스템 관점에서 효과 척도를 만족할 수 있는 설계 변수 조합 범위를 제시하였다. 표적의 위치 예측과 함께 프레임률, 영상처리 소요시간과 측정 오차, 표적 궤적특성 및 마운트 김발의 기동성능 등의 설계 변수를 고려하여 전체적인 시스템 수준에서의 시뮬레이션을 구현하고 추적 성능을 분석하였다. 분석 결과 광학 관측 시스템의 연속 추적 성능은 프레임률과 마운트 기동성능의 조합에 의존적임을 확인할 수 있었다. 광학 관측 시스템을 설계하거나 상용 제품을 구입하여 유사 시스템을 구성할 때, 본 연구와 같이 효과분석 시뮬레이션을 이용하면 설계 변수들 사이의 적절한 요소 조합을 찾을 수 있을 것이다.

• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.718-724
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• 2013

In today's automotive industry, there exist several systems that help drivers reduce the possibility of accidents, such as the ADAS (Advanced Driver Assistance System). The ADAS helps drivers make correct and quick decisions during dangerous situations. This study analyzed the performance of the IMM (Interacting Multiple Model) method based on multiple Kalman filters using the data acquired from a driving simulator. An IMM algorithm is developed to identify the current discrete state of neighboring vehicles using the sensor data and the vehicle dynamics. In particular, the driving modes of the neighboring vehicles are classified by the cruising and maneuvering modes, and the transition between the states is modeled using a Markovian switching coefficient. The performance of the IMM algorithm is analyzed through realistic simulations where a target vehicle executes sudden lane change or acceleration maneuver.

• 한국군사과학기술학회지
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• 제10권4호
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• pp.145-151
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• 2007

This paper considers new filter gains for the ${\alpha}\;-\;{\beta}$ tracker which is optimized particularly to minimize the tracking gate size. Optimizing the performance index which is composed of tracking errors due to target maneuver and measurement noise is not different from the existing method to obtain the ${\alpha}\;-\;{\beta}$ gains. However, holding the probability 0.997 that a target exists in the tracking gate and minimizing the gate size produce the new result not similar to the existing ${\alpha}\;-\;{\beta}$ gains.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.506-509
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• 2005

An adaptive ${\alpha}-{\beta}$ tracker is proposed for tracking maneuvering targets with a track-while-scan radar system. The tracker gain is updated on-line corresponding to the adjusted process noise variance which is obtained via time averaging of the process over a sliding window. The adjusted process noise variance is used to compute the maneuverability index for the tracker gain based on the steady-state Kalman filter equation for each epoch. It is shown via simulation that the proposed approach provides robust and accurate position estimates during the target maneuver while the performance of the conventional ${\alpha}-{\beta}$ tracker is shown much degraded.

• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.947-953
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• 2011

Radome aberration error causes degradation of miss distance as well as stability of high maneuver missile system with RF seeker. A study about radome compensation method is important in this kind of missile system design. Several kinds of methods showed good compensation performance in their paper. Proposed adaptive Particle filter estimates line of sight rate excluding the radome induced error. This paper shows effectiveness of adaptive Particle filter as compensation method of radome aberration error. Robust performance of this filter depends on external aiding measurement, target acceleration. Tuning of system error covariance can make this filter unsensitive against the error of target acceleration information. This paper demonstrates practical usage of adaptive Particle filter for reducing miss distance and increasing stability against disturbance of radome aberration error through performance analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.192-194
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• 1995

An improved filter for tracking a maneuvering target is presented. The proposed filter consists of two kalman filters based on different dynamic models and double decision logic. The use of double decision logic for the maneuver onset and ending detection leads to reduction in estimation error. This decision rule is based on evidence theory, Dempster-Shafer theory, which is extended in order to be applicable in the tracking problem. Simulation results show that the proposed filter performs better than IMM at a lower computational load.

• International Journal of Aeronautical and Space Sciences
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• 제12권3호
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• pp.260-265
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• 2011

In this paper, integrated missile guidance and control systems using time-delay control (TDC) are developed. The next generation missile requires that an interceptor hits the target, maneuvering with small miss-distances, and has lower weight to reduce costs. This is possible if the synergism existing between the guidance and control subsystems is exploited by the integrated controller. The TDC law is a robust control technique for nonlinear systems, and it has a very simple structure. The feature of TDC is to directly estimate the unknown dynamics and the unexpected disturbance using one-step time-delay. To investigate the performance of the integrated controller, numerical simulations are performed as the maneuver of the target. The results show that the integrated guidance and control system has a good performance.