• 정보저장시스템학회논문집
• /
• 제2권1호
• /
• pp.56-64
• /
• 2006

This paper proposes a new and simple input prediction method for robust servo system. A robust tracking control system for optical disk drives to reject disk runout was recently proposed based on both Coprime Factorization(CF) and Zero Phase Error Tracking(ZPET) control. The CF control system can be designed simply and systematically. Moreover, this system has not only stability but also robustness to parameter uncertainties and disturbance rejection capability. Since optical disk tracking servo systems can detect only racking error, it was proposed that the reference input signal for ZPET could be estimated from tracking errors. In this paper, we propose a new control structure for the ZPET controller. It requires less memory than the previously proposed method for the reference signal generation. Therefore, it is very effective in runout control. Furthermore, this method can be applied to defective optical disk like surface defects on disk. Numerical simulation and experimental result show the proposed method effective.

• International Journal of Control, Automation, and Systems
• /
• 제3권4호
• /
• pp.552-563
• /
• 2005

In this paper, we propose a wavelet based fuzzy neural network (WFNN) based direct adaptive control scheme for the solution of the tracking problem of mobile robots. To design a controller, we present a WFNN structure that merges the advantages of the neural network, fuzzy model and wavelet transform. The basic idea of our WFNN structure is to realize the process of fuzzy reasoning of the wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. In our control system, the control signals are directly obtained to minimize the difference between the reference track and the pose of a mobile robot via the gradient descent (GD) method. In addition, an approach that uses adaptive learning rates for training of the WFNN controller is driven via a Lyapunov stability analysis to guarantee fast convergence, that is, learning rates are adaptively determined to rapidly minimize the state errors of a mobile robot. Finally, to evaluate the performance of the proposed direct adaptive control system using the WFNN controller, we compare the control results of the WFNN controller with those of the FNN, the WNN and the WFM controllers.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.2254-2259
• /
• 2005

In this paper, we propose a wavelet based fuzzy neural network(WFNN) based direct adaptive control scheme for the solution of the tracking problem of mobile robots. To design a controller, we present a WFNN structure that merges advantages of neural network, fuzzy model and wavelet transform. The basic idea of our WFNN structure is to realize the process of fuzzy reasoning of wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. In our control system, the control signals are directly obtained to minimize the difference between the reference track and the pose of mobile robot using the gradient descent(GD) method. In addition, an approach that uses adaptive learning rates for the training of WFNN controller is driven via a Lyapunov stability analysis to guarantee the fast convergence, that is, learning rates are adaptively determined to rapidly minimize the state errors of a mobile robot. Finally, to evaluate the performance of the proposed direct adaptive control system using the WFNN controller, we compare the control performance of the WFNN controller with those of the FNN, the WNN and the WFM controllers.

• 전자공학회논문지
• /
• 제52권5호
• /
• pp.206-213
• /
• 2015

함정용 전자광학추적장비의 센서부에서 해수면반사파에 의해 발생하게 되는 영상추적간섭 현상을 최소화하고자 전방향성, 점진적인 굴절률 및 표면 요철구조를 갖는 산화아연에 플루오르화마그네슘을 코팅한 반사방지막을 전자빔 증착 장비를 통해 제작하였다. 최적화된 산화아연에 플루오르화마그네슘을 코팅한 반사방지막은 기존의 산화아연 반사방지막과 비교하여 점진적인 굴절률 변화에 따라 표면 프레넬 반사를 최소화하고 이를 통해 전자광학추적장비의 영상추적간섭 현상을 제거하는 장점이 있다. 본 실험을 통해, 산화아연에 플루오르화마그네슘을 코팅한 반사방지막이 다양한 전자광학장비의 반사방지막으로써 적용이 가능함을 확인하였다.

• 전기전자학회논문지
• /
• 제24권2호
• /
• pp.392-402
• /
• 2020

본 논문은 광센서 없는 태양광 추적 시스템을 제안한다. 태양광 추적, MPPT, ESS, 모니터링의 4가지 기능을 모듈화하여 시스템을 구현하였다. 9개의 태양광 패널을 기본단위로, 바람의 영향을 저감하고, 광센서 없이 태양광 추적이 가능하도록 상하좌우 패널의 높낮이를 다르게 한 격자형 구조를 채택하였다. 저가형 MCU를 이용한 부스트 컨버터 PWM 스위칭을 위해 기존 MPPT의 연산 방법을 개선하였다. ESS 모듈은 리튬 이온 배터리 12개(직렬 3셀과 병렬 4셀)를 기본 단위로 구성하여 온도 및 전기 특성의 이상 유무 감시가 가능하게 하였다. 각 모듈의 MCU는 Atmega128 또는 Raspberry PI로 구성하였으며 운전 정보를 상호 교환하고, IoT 기술을 응용하여 실시간 원격 모니터링과 클라우드에 데이터베이스를 구축하여 유지보수가 가능하게 하였다. 실험을 위해 제작된 태양광 발전 시스템의 운전 데이터는 각 모듈의 분산 및 원격 모니터링의 가능성, 유지보수의 편의성 및 광추적 성능을 증명한다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
• /
• pp.15-22
• /
• 2006

This paper presents a novel signal tracking algorithm for GNSS receivers using a MLE technique. In order to perform a robust signal tracking in severe signal environments, e.g., high dynamics for navigation vehicles or weak signals for indoor positioning, the MLE based signal tracking approach is adopted in the paper. With assuming white Gaussian additive noise, the cost function of MLE is expanded to the cost function of NLSE. Efficient and practical approach for Doppler frequency tracking by the MLE is derived based on the assumption of code-free signals, i.e., the cost function of the MLE for carrier Doppler tracking is used to derive a discriminator function to create error signals from incoming and reference signals. The use of the MLE method for carrier tracking makes it possible to generalize the MLE equation for arbitrary codes and modulation schemes. This is ideally suited for various GNSS signals with same structure of tracking module. This paper proposes two different types of MLE based tracking method, i.e., an iterative batch processing method and a non-iterative feed-forward processing method. The first method is derived without any limitation on time consumption, while the second method is proposed for a time limited case by using a 1st derivative of cost function, which is proportional to error signal from discriminators of conventional tracking methods. The second method can be implemented by a block diagram approach for tracking carrier phase, Doppler frequency and code phase with assuming no correlation of signal parameters. Finally, a state space form of FLL/PLL/DLL is adopted to the designed MLE based tracking algorithm for reducing noise on the estimated signal parameters.

• 한국멀티미디어학회논문지
• /
• 제20권7호
• /
• pp.986-993
• /
• 2017

Object Tracking is a technique for tracking moving objects over time in a video image. Using object tracking technique, many research are conducted such a detecting dangerous situation and recognizing the movement of nearby objects in a smart car. However, it still remains a challenging task such as occlusion, deformation, background clutter, illumination variation, etc. In this paper, we propose a novel deep visual object tracking method that can be operated in robust to many challenging task. For the robust visual object tracking, we proposed a Convolutional Neural Network(CNN) which shares weight of the convolutional layers. Input of the CNN is a three; first frame object image, object image in a previous frame, and current search frame containing the object movement. Also we propose a method to consider the motion of the object when determining the current search area to search for the location of the object. Extensive experimental results on a authorized resource database showed that the proposed method outperformed than the conventional methods.

• 한국실내디자인학회논문집
• /
• 제28호
• /
• pp.140-148
• /
• 2001

The purpose of this thesis is to provide basic information of efficient flow line arrangement, which results from examining the factors of route choice with a focus on the store' space elements and pedestrian activity patterns in the outlets. The route tracking is applied to grasp pedestrian activity patterns, therefore, a concrete analysis into influential factors of the space structure arrangement and forms on route choice. The route tracking is a means to understand pedestrian activity patterns by establishing an unrecognizable space and examining every route in the investigating area for pedestrian activity pattern research. Three sample stores have different systems in the ground plan structures, the escalator location and the directions. The analysis focuses on the booth arrangement and shopping patterns. In conclusion, route choice of the customers and the structure of the space are quite closely related and affect the quality of shopping. This can suggest evidence for the need of the space structure to meet the pedestrian activity patterns.

• 제어로봇시스템학회논문지
• /
• 제9권10호
• /
• pp.747-754
• /
• 2003

An enhancement of the probabilistic data association filter is presented for tracking a single maneuvering target in clutter environment. The use of the variable dimensional structure leads the probabilistic data association filter to adjust to real motion of a target. The detection of the maneuver for the model switching is performed by the acceleration estimates taken from a bias estimator of the two stage Kalman filter. The proposed algorithm needs low computational power since it is implemented with a single filtering procedure. A simple Monte Carlo simulation was performed to compare the performance of the proposed algorithm and the IMMPDA filter.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1574-1579
• /
• 2004

A simultaneous measurement system that can analyze the flow-structure interactions(FSI) has been constructed and analyses on the flow field and the motion field of a floating cylinder was made. The three-dimensional vector fields around the cylinder are measured by 3D-PTV technique while the motion of the cylinder forced by the flow field is measured simultaneously with a newly developed motion tracking algorithm(bidirectional tracking algorithm). The cylinder is pendant in the working fluid of a water channel and the surface of the working fluid is forced sinusoidal to make the cylinder bounced. The interaction between the flow fields and the cylinder motion is examined quantitatively.