• 한국군사과학기술학회지
• /
• 제1권1호
• /
• pp.211-218
• /
• 1998

As a part of trajectory modulation to increase system survivability and terminal effectiveness, impact angle control is required in the terminal phase of tactical missile systems. The missile systems are not allowed to have high altitude to reduce probability of detection by sensors of missile defense systems. In this paper, an analytic form of a time-optimal control law is suggested in the case of constrained missile maneuverability and impact angle under the assumption of a zero-lag autopilot. The control law is obtained by establishing optimal missile-target engagement geometry in the vertical plane. Extension of the law for missiles with autopilot response lags requiring a numerical solution is studied by introducing an iterative algorithm for optimal switching time determination of which the initial switching instants are obtained from the analytic solution. Also suggested is a closed-form impact angle control law derived by an energy-optimal approach. The performances of the proposed guidance laws are evaluated by a series of computer runs.

• Journal of applied mathematics & informatics
• /
• 제19권1_2호
• /
• pp.203-214
• /
• 2005

In this study the optimal control of fed-batch glycerol fermentation is investigated based on an impulsive dynamical system. Considering the sudden increase of the glycerol and alkali in fed-batch culture of biodissimilation of glycerol to 1,3-propanediol, this paper proposes a non-linear impulsive system of fed-batch culture. The existence, uniqueness and regularity properties of piecewise solution for the system are proved. In view of the controllability of volumes of glycerol added to the reactor instantaneously, the paper constructs an optimal control model based on the nonlinear impulsive system and the existence of the optimal control is obtained. The control variables here are the moments and the sizes of jumps in the states at the discrete instants and the objective is to maximize the productivity of 1,3-propanediol over one cycle.

• 대한전기학회논문지
• /
• 제39권10호
• /
• pp.1075-1085
• /
• 1990

This paper presents a new method for the optimal control of the distributed parameter systems by a decentralized computational procedure. Approximate lumped parameter models are derived by using the Galerkin method employing the Legendre polynomials as the basis functions. The distributed parameter systems, however, are transformed into the large scale lumped parameter models. And thus, the decentralized control scheme is introduced to determine the optimal control inputs for the obtained lumped parameter models. In addition, an approach to block pulse functions is applied to solve the optimal control problems of the obtained lumped parameter models. The proposed method is simple and efficient in computation for the optimal control of distributed paramter systems. Illustrative examples given to demonstrate the validity of the presently proposed method.

• 동력기계공학회지
• /
• 제8권1호
• /
• pp.69-74
• /
• 2004

A structure-control combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. A numerical example shows the validity of combined optimal design of structure and control systems. We also consider the validity of sensor-actuator collocation for control system design in this paper.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2007년도 동계학술발표대회 논문집
• /
• pp.46-51
• /
• 2007

The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air temperature and chilled water temperature. This study has been done by using LapVIEW program with PID control in order to analyze the central cooling system energy saving.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.455-458
• /
• 2003

An optimal control approach to robust control design is proposed in this study for rigid robotic systems under the unknown load and the other uncertainties. The uncertainties are quadratically bounded for some positive definite matrix. Iterative method to find the matrix is shown. Simulations arc made for a weight-lifting operation of a two-link manipulator and the robust control performance of robotic systems by the proposed algorithm is remarkable.

• 한국정밀공학회지
• /
• 제20권12호
• /
• pp.176-182
• /
• 2003

An optimal control approach to robust control design is proposed in this study for rigid robotic systems under the unknown load and the other uncertainties. The uncertainties are quadratically bounded for some positive definite matrix. Iterative method to find the matrix is shown. Simulations are made for a weight-lifting operation of a two-link manipulator and the robust control performance of robotic systems by the proposed algorithm is remarkable.

• 한국정보통신학회논문지
• /
• 제20권4호
• /
• pp.698-706
• /
• 2016

이동로봇을 원하는 위치로 최단시간 안에 이동시키기 위해 최적제어문제를 풀어야 하지만 비선형시스템이므로 해석적 접근이 매우 어렵다. 본 논문에서 유전알고리즘을 사용하여 이동로봇의 최적제어이득을 구한다. 로봇 방정식이 비선형식이므로 초기치에 따라 최적제어이득은 다르게 결정된다. 따라서 초기치 범위를 적절한 개수의 격자점으로 이산화시킨 뒤 해당 격자점에서 유전알고리즘으로 최적제어이득을 구한다. 일반적인 초기치에 대한 제어이득은 신경회로망으로 구하며 해당 격자점의 초기치와 그에 대한 최적제어이득을 신경회로망 학습데이터로 사용하고 학습시킨다. 이산화된 격자점이 아닌 다른 초기치에 대한 제어이득은 신경회로망으로부터 구한다. 마지막으로 본 논문의 제어방법의 유용성을 시뮬레이션 연구로 확인하고자 한다.

• International Journal of Control, Automation, and Systems
• /
• 제1권3호
• /
• pp.282-288
• /
• 2003

It is known that HIV (Human Immunodeficiency Virus) infection, which causes AIDS after some latent period, is a dynamic process that can be modeled mathematically. Effects of available anti-viral drugs, which prevent HIV from infecting healthy cells, can also be included in the model. In this paper we illustrate control theory can be applied to a model of HIV infection. In particular, the drug dose is regarded as control input and the goal is to excite an immune response so that the symptom of infected patient should not be developed into AIDS. Finite horizon optimal control is employed to obtain the optimal schedule of drug dose since the model is highly nonlinear and we want maximum performance for enhancing the immune response. From the simulation studies, we found that gradual reduction of drug dose is important for the optimality. We also demonstrate the obtained open-loop optimal control is vulnerable to parameter variation of the model and measurement noise. To overcome this difficulty, we finally present nonlinear receding horizon control to incorporate feedback in the drug treatment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1784_1785
• /
• 2009

This paper presents sliding mode control and optimal control techniques for controlling the speed of permanent magnet synchronous motor. Virtual sliding surface has nominal dynamics of an original system. The performance of the system with sliding mode control and optimal control is compared with the response of the nominal system. As a result, the sliding mode control and optimal control has robustness against the system uncertainties.