• 한국음향학회지
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• 제33권4호
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• pp.225-231
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• 2014

본 논문은 해양에서 발생하는 음향 표적에 대해서 표적의 식별 정보 피드백을 통해 관심 표적 추적 성능을 향상시키는 기법을 제안한다. 기존의 다중주파수 표적 추적 기법은 탐지된 음향신호 특성만 활용하여 추적을 수행하는 반면, 본 논문에서 제안하는 기법은 탐지된 음향신호 특성과 더불어 관심 표적의 특징인자가 식별되는지 여부를 추적에 활용한다. 제안하는 기법은 특징인자가 식별되는 측정치에 대해서만 추적을 수행하여 관심 표적이 아닌 표적에 대한 불필요한 추적을 방지한다. 또한 특징인자가 식별된 표적을 추적할 때 동적으로 추적 파라메터를 최적화하여 관심 표적에 대해 지속적이고 안정적인 추적을 수행한다. 모의 신호를 이용하여 실험을 수행하였으며 미약한 신호가 나타나는 수중 표적에 대해 제안하는 기법을 적용한 결과, 불필요한 표적 개수가 감소하고 관심 표적의 추적이 지속적으로 안정되게 수행됨을 확인하였다.

• 제어로봇시스템학회논문지
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• 제7권5호
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• pp.445-453
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• 2001

The multiple targets tracking problem has been one of the main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimen-sion filter, input estimation filter, interacting multiple model(IMM) filter, dederated variable dimension filter with input estimation, etc., have proposed to address the tracking and sensor fusion issues. In this pa- per, two existing tracking algorithm, i.e, the IMM filter and the variable dimension filter with input estima-tion(VDIE), are combined for the purpose of improving the tracking performance for maneuvering targets. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns, i.e., waver, pop-up, and high-diver motions, are defined and are applied to the modified IMM filter as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMM filter than the standard IMM filter are demonstrated though computer simulations.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권7_8호
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• pp.713-718
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• 2003

조건부 밀도 전파(Condensation)는 강건한 추적 성능과 실시간 구현이 가능하다는 장점을 지닌다. 그러나 정확한 추적을 수행하기 위해서는 복잡한 형태 모델과 많은 수의 샘플을 요구하므로 현실적으로 실시간 다중 추적에 적합하지 않은 경우가 많다. 본 논문에서는 실시간 응용에 적합하도록 작은 탐색 공간을 갖는 이산 형태의 형태 모델과 다중 추적 시각 추적기간의 상호 경쟁 관계를 고려하여 적은 수의 샘플로도 좋은 추적 성능을 보이는 경쟁적 Condensation 알고리즘을 제안한다. 실험 결과, 제안한 경쟁적 추적 알고리즘은 복잡하게 이동하는 여러 군중을 실시간으로 강건하게 추적함을 보인다.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1044-1052
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• 2010

In this paper, a new realtime algorithm called the RTPBTD-HPDAF (Recursive Temporal Profile Base Target Detection with Highest Probability Data Association Filter) is presented for tracking fast moving small targets with IIR (Imaging Infrared) sensor systems. Spatial filter algorithms are mainly used for target in IIR sensor system detection and tracking however they often generate high density clutter due to various shapes of cloud. The TPBTD (Temporal Profile Base Target Detection) algorithm based on the analysis of temporal behavior of individual pixels is known to have good performance for detection and tracking of fast moving target with suppressing clutter. However it is not suitable to detect stationary and abruptly maneuvering targets. Moreover its computational load may not be negligible. The PTPBTD-HPDAF algorithm proposed in this paper for real-time target detection and tracking is shown to be computationally cheap while it has benefit of tracking targets with abrupt maneuvers. The performance of the proposed RTPBTD-HPDAF algorithm is tested and compared with the spatial filter with HPDAF algorithm for run-time and track initiation at real IIR video.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.703-710
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• 2014

An Image-Based Target Tracker maintains LOS(Line Of Sight) to a target by controlling azimuth and elevation gimbals of an ISS(Inertially Stabilized System). Its controller produces the gimbals commands of the ISS using tracking errors provided by an image tracker. The control performance of the target tracker with PI controller generally used for tracking controller is limited because of bandwidth limitation by time delay yielded by image capture and processing of the image tracker. In this paper, tracking controller using target states estimator is proposed which can enhance the tracking performance under the highly dynamic maneuvering conditions of the ISS and the target. Simulation results show that the proposed method can improve the tracking performance than that with only PI controller.

• 한국태양에너지학회 논문집
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• 제29권1호
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• pp.50-57
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• 2009

Heliostat in the tower type solar thermal power plant is a mirror system tracking the sun's movement to collect the solar energy and it is the most important subsystem determining the efficiency of solar thermal power plant. Thus a good performance of it, which is mostly the accurate sun tracking performance under the various hazardous operating condition, is required. Heliostat control system is a system to manage the heliostat sun tracking movement and other operations. It also communicates with the master controller through the heliostat filed control system to receive and send the informations required to operate the heliostat as a part of the solar thermal power plant. This study presents a heliostat control system designed and developed for the 1MW solar thermal power plant. We first define the functionality of heliostat control system. Then sun tracking controller as well as the sun tracking algorithm satisfying the required functionality have been developed. We tested the developed heliostat control system and it showed a good performance in regulation of heliostat motion and communication.

• 한국통신학회논문지
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• 제28권12A호
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• pp.983-990
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• 2003

본 논문에서는 3GPP 모뎀용 비동기식 동기추적회로(noncoherent code tracking loop)를 설계하고 설계된 회로의 정상상태 지터 분산(steady-state jitter variance)과 과도응답 특성(transient response characterisitc)을 해석한다. 먼저, AWGN 환경에서의 지터 분산을 펄스성형 필터(pulse-shaping filter), 타이밍 오프셋(timing offset), 신호 대잡음비(signal-to-interference ratio), 루우프 대역폭(loop bandwidth)에 대한 일반식으로 유도하고, 과도응답 특성을 이론적으로 해석한다. 이를 바탕으로, 디지털 하드웨어 구현이 용이한 가변 대역폭 동기추적회로를 설계하며 설계된 회로와 고정 대역폭 시스템의 성능을 이론적으로 비교, 분석하고 컴퓨터 시뮬레이션을 통해 검증한다.

• 한국인터넷방송통신학회논문지
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• 제12권1호
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• pp.195-200
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• 2012

본 논문에서는 동시통화에 강인한 특성을 갖는 알고리즘의 추적성능을 개선시킬 수 있는 새로운 방법을 제안하였다. 반향경로의 변화를 검출하는 방법과 적응필터의 계수 적응식을 변경하는 방법을 제안하였다. 오차신호 대 스케일 파라메터의 비는 반향경로가 변화한 경우와 동시통화가 발생한 경우에 지속시간이 다른 특성을 가지며 이를 이용하여 반향경로 변화를 검출한다. 제안한 적응필터계수 적응식은 잘못된 오차신호선택을 방지하도록 하여 추적 성능을 개선시킨다. 실제 음성신호와 ITU-T G.168에서 제공하는 반향경로를 사용한 실험을 통하여 제안한 방법이 기존의 방법에 비해 4dB 이상 성능을 개선시킴을 확인하였다.

• 한국멀티미디어학회논문지
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• 제16권11호
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• pp.1261-1271
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• 2013

Zoom tracking involves the automatic adjustment of the focus motor in response to the zoom motor movements for the purpose of keeping an object of interest in focus, and is typically achieved by moving the zoom and focus motors in a zoom lens module so as to follow the so-called "trace curve", which shows the in-focus motor positions versus the zoom motor positions for a specific object distance. Thus, one can simply implement zoom tracking by following the most closest trace curve after all the trace curve data are stored in memory. However, this approach is often prohibitive in practical implementation because of its large memory requirement. Many other zoom tracking methods such as GZT, AZT and etc. have been proposed to avoid large memory requirement but with a deteriorated performance. In this paper, we propose a new zoom tracking method called 'Approximate Feedback Zoom Tracking method (AFZT)' on DM36x-based IP network camera, which does not need large memory by approximating nearby trace curves, but generates better zoom tracking accuracy than GZT or AZT by utilizing focus value as feedback information. Experiments through real implementation shows the proposed zoom tracking method improves the tracking performance and works in real-time.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.536-542
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• 2016

To enhance tracking efficiency, a target-tracking filter with a resource management algorithm is required. One of the resource management algorithms chooses or evaluates the proper sampling time using cost functions which are related to the target tracking filter. We propose a resource management algorithm for bearing only tracking environments. Since the tracking performance depends on the system observability, the bearing-only tracking is one of challenging target-tracking fields. The proposed algorithm provides the adaptive sampling time using the variation rate of the error covariance matrix from the target-tracking filter. The simulation verifies the efficiency performance of the proposed algorithm.