• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
• /
• pp.456-461
• /
• 1989

In this paper, the robust adaptive controller for the accurate position control of the robot manipulator in discribed. The proposed controller has feedforward and feedback terms. To reduced the cumputation time, the inertia matrix is simlipied by diagonal matrix and the centrifugal and Colioris term and gravity term are assumed to be zero. The auxiliary signal is added in the controller. This signal improve convergence time of error. The simulation results show that the proposed method is applied to the real time control.

• KIEE International Transaction on Systems and Control
• /
• 제12D권1호
• /
• pp.39-42
• /
• 2002

This paper focuses on the asymptotic stability of a class of neutral linear systems with mixed time-varying delay arguments. Using the Lyapunov method, a delay-dependent stability criterion to guarantee the asymptotic stability for the systems is derived in terms of linear matrix inequalities (LMIs). The LMIs can be easily solved by various convex optimization algorithms. Two numerical examples are given to illustrate the proposed methods.

• 전기학회논문지
• /
• 제60권3호
• /
• pp.620-624
• /
• 2011

This paper propose a new delay-dependent stability criterion of neutral time-delay systems. By employing double-integral terms in augmented states and constructing a new Lyapunov-Krasovskii's functional, a delay-dependent stability criterion is established in terms of Linear Matrix Inequality. Through numerical examples, the validity and improvement results obtained by applying the proposed stability criterion will be shown.

• 전기학회논문지
• /
• 제58권11호
• /
• pp.2261-2265
• /
• 2009

In this paper, the problem of delay-dependent stability of uncertain stochastic systems with time-varying delay is considered. The uncertainties are assumed to be norm-bounded. Based on the Lyapunov stability theory, new delay-dependent stability criteria for the system are derived in terms of LMI(linear matrix inequality). Two numerical examples are given to show the effectiveness of proposed method.

• International Journal of Automotive Technology
• /
• 제2권3호
• /
• pp.117-122
• /
• 2001

For a dynamic analysis of a constrained multibody system, it is necessary to have a routine for satisfying kinematic constraints. LU decomposition scheme, which is used to divide coordinates into dependent and independent coordinates, is efficient but has great difficulty near the singular configuration. Other method such as the projection matrix, which is more stable near a singular configuration, takes longer simulation time due to the large amount of calculation for decomposition. In this paper, the row space and the null space of the Jacobian matrix are proposed by using the pseudo-inverse method and the projection matrix. The equations of the motion of a system are replaced with independent acceleration components using the null space of the Jacobian matrix. Also a new hybrid method is proposed, combining the LU decomposition and the projection matrix. The proposed hybrid method has following advantages. (1) The simulation efficiency is preserved by the LU method during the simulation. (2) The accuracy of the solution is also achieved by the projection method near the singular configuration.

• Communications for Statistical Applications and Methods
• /
• 제20권3호
• /
• pp.235-240
• /
• 2013

Generalized linear mixed models(GLMMs) are frequently used for the analysis of longitudinal categorical data when the subject-specific effects is of interest. In GLMMs, the structure of the random effects covariance matrix is important for the estimation of fixed effects and to explain subject and time variations. The estimation of the matrix is not simple because of the high dimension and the positive definiteness; subsequently, we practically use the simple structure of the covariance matrix such as AR(1). However, this strong assumption can result in biased estimates of the fixed effects. In this paper, we introduce Bayesian modeling approaches for the random effects covariance matrix using a modified Cholesky decomposition. The modified Cholesky decomposition approach has been used to explain a heterogenous random effects covariance matrix and the subsequent estimated covariance matrix will be positive definite. We analyze metabolic syndrome data from a Korean Genomic Epidemiology Study using these methods.

• 대한원격탐사학회지
• /
• 제28권1호
• /
• pp.55-67
• /
• 2012

멀티센서 시스템으로부터 취득된 영상을 이용하여 공간정보를 신속하게 생성하기 위해서 영상의 실시간 지오레퍼런싱이 요구된다. 위치/자세 센서의 성능을 보완하며 실시간 처리가 가능하려면 연속 추정 알고리즘을 활용한 온라인 항공삼각측량이 수행되어야 한다. 본 연구는 연속적으로 취득되는 영상의 실시간 지오레퍼런싱을 위한 효율적인 온라인 항공삼각측량 방법론을 도출하고자 한다. 기존의 기븐스 변환 갱신 알고리즘과 최근 개발된 관측값 분류에 기반한 정규행렬 역행렬 갱신 알고리즘을 활용하여 온라인 항공삼각 측량을 구현하였다. 정확도와 연산 속도 측면에서 두 알고리즘의 성능을 비교 검증하기 위하여 항공 멀티센서 시스템으로부터 취득된 센서 데이터를 모의 생성하고 이를 적용하였다. 적용 결과, 관측값 분류에 기반한 정규행렬 역행렬 갱신에 의한 온라인 항공삼각측량이 기븐스 변환에 의한 방법보다 추정된 지상점 좌표에 대하여 40 % 이상 높은 정확도를 보이고, 8배 이상의 빠른 처리 속도를 나타내었다. 따라서, 영상의 실시간 지오레퍼런싱을 위하여 정규행렬 역행렬 갱신에 의한 온라인 항공삼각측량이 더 적합한 것으로 판단되었다.

• 한국지능시스템학회논문지
• /
• 제10권5호
• /
• pp.423-431
• /
• 2000

In this paper, the effect of computing time-delay in the real-time digital fuzzy control systems is investigated and the design methodology of a real-time digital fuzzy controller(DFC) to overcome the problems caused by it is presented. We propose the fuzzy feedback controller whose output is delayed with unit sampling period. The analysis and the design problem considering computing time-delay is very easy because the proposed controller is syncronized with the sampling time. The stabilization problem of the digital fuzzy control system is solved by the linear matrix inequality(LMI) theory. Convex optimization techniques are utilized to find the stable feedback gains and a common positive definite matrix P for the designed fuzzy control system Furthermore, we develop a real-time fuzzy control system for backing up a computer-simulated truck-trailer with the consideration of the computing time-delay. By using the proposed method, we design a DFC which guarantees the stability of the real time digital fuzzy control system in the presence of computing time-delay.

• 제어로봇시스템학회논문지
• /
• 제5권6호
• /
• pp.641-646
• /
• 1999

This paper deals with the robust stability of discrete-time linear systems with time- varying delays and norm-bounded uncertainties. In this paper, the magnitude of time-varying delays is assumed to be upper-bounded. The sufficient condition is presented in terms of linear matrix inequality. It is also shown that the robust stability of uncertain discrete-time linear systems with time-varying delays is related with the quadratic stability of uncertain discrete-time linear systems with constant time delay.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1682-1691
• /
• 2015

In this paper, a real time implementation of selective harmonic elimination pulse width modulation (SHEPWM) using Real Coded Genetic Algorithm (RGA), Particle Swarm Optimization technique (PSO) and a new technique known as Linearization Method (LM) for Single Phase Matrix Converter (SPMC) is designed and discussed. In the proposed technique, the switching frequency is fixed and the optimum switching angles are obtained using simple mathematical calculations. A MATLAB simulation was carried out, and FFT analysis of the simulated output voltage waveform confirms the effectiveness of the proposed method. An experimental setup was also developed, and the switching angles and firing pulses are generated using Field Programmable Gate Array (FPGA) processor. The proposed method proves that it is much applicable in the industrial applications by virtue of its suitability in real time applications.