• Title/Summary/Keyword: Optimal Control

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Optimal Loudspeaker Positions of an Active Noise Control System with an Opening in an Enclosure (개구부를 가지는 실내의 능동소음제어시스템에서의 최적스피커 위치)

  • 백광현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.788-791
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    • 2003
  • Optimal loudspeaker positions are important as much as the control algorithms and hardware performance in the active noise control system. This study is similar to the past researches on the optimal transducer locations but with a far field noise source having a plane wave characteristic and the noise coming through an opening such as a window in the enclosure. An optimization technique called simulated annealing algorithm is used to find a set of optimal loudspeaker positions from a larger possible loudspeaker positions. Loudspeakers are placed on the surface of opening at the wail. Using the measured acoustic transfer impedances and numerical simulations with the optimization technique, optimal positions we identified and compared. When a small number of loudspeakers are used, loudspeaker positions on the opening near the center seems to be the best place, but when a larger number of loudspeakers are used it was difficult to find simple patterns Un the optimal positions.

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Real-Time Prediction of Optimal Control Parameters for Mobile Robots based on Estimated Strength of Ground Surface (노면의 강도 추정을 통한 자율 주행 로봇의 실시간 최적 주행 파라미터 예측)

  • Kim, Jayoung;Lee, Jihong
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.1
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    • pp.58-69
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    • 2014
  • This paper proposes a method for predicting maximum friction coefficients and optimal slip ratios as optimal control parameters for traction control or slip control of autonomous mobile robots on rough terrain. This paper focuses on strength of ground surface which indicates different characteristics depending on material types on surface. Strength of various material types can be estimated by Willoughby sinkage model and by a developed testbed which can measure forces, velocities, and displacements generated by wheel-terrain interaction. Estimated strength is collaborated on building improved Brixius model with friction-slip data from experiments with the testbed over sand and grass material. Improved Brixius model covers widespread material types in outdoor environments on predicting friction-slip characteristics depending on strength of ground surface. Thus, a prediction model for obtaining optimal control parameters is derived by partial differentiation of the improved Brixius model with respect to slip. This prediction model can be applied to autonomous mobile robots and finally gives secure maneuverability on rough terrain. Proposed method is verified by various experiments under similar conditions with the ones for real outdoor robots.

A MULTIGRID METHOD FOR AN OPTIMAL CONTROL PROBLEM OF A DIFFUSION-CONVECTION EQUATION

  • Baek, Hun-Ki;Kim, Sang-Dong;Lee, Hyung-Chun
    • Journal of the Korean Mathematical Society
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    • v.47 no.1
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    • pp.83-100
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    • 2010
  • In this article, an optimal control problem associated with convection-diffusion equation is considered. Using Lagrange multiplier, the optimality system is obtained. The derived optimal system becomes coupled, non-symmetric partial differential equations. For discretizations and implementations, the finite element multigrid V-cycle is employed. The convergence analysis of finite element multigrid methods for the derived optimal system is shown. Some numerical simulations are performed.

ANALYSIS AND COMPUTATIONS OF OPTIMAL AND FEEDBACK CONTROL PROBLEMS FOR NAVIER-STOKES EQUATIONS

  • Lee, Hyung-Chun
    • Journal of the Korean Mathematical Society
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    • v.34 no.4
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    • pp.841-857
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    • 1997
  • We present analysis and some computational methods for boundary optimal and feedback control problems for Navier-Stokes equations. We use one example to illustrate our methodology and ideas which are applicable to general control problems for Navier-Stokes equations. First, we discuss the existence of optimal solutions and derive an optimality system of equations from which an optimal solution may be computed. Then we present a gradient type iterative method. Finally, we present some numerical results.

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Optimal Control of Dualistic Economic Growth

  • Park, Sung-Joo
    • Journal of Korean Institute of Industrial Engineers
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    • v.4 no.2
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    • pp.107-118
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    • 1978
  • The paper illustrates a possible application of control theory to an economic growth system. Simultaneous nonlinear system of differential equations has been modeled which is different from the traditional formulation, based on the theory of economic growth for a two-sector (dual) economy. Necessary and sufficient conditions for the existence of the optimal control are derived directly from the Hamiltonian, and the optimal controls are also obtained by solving simultaneous equations. Obtaining the trajectories of the optimal control and state variables, however, should rely on the numerical procedures. Empirical application has been conducted for the case of the Korean economy as an illustration.

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OPTIMAL CONTROL PROBLEM FOR HOST-PATHOGEN MODEL

  • P. T. Sowndarrajan
    • Nonlinear Functional Analysis and Applications
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    • v.28 no.3
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    • pp.659-670
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    • 2023
  • In this paper, we study the distributed optimal control problem of a coupled system of the host-pathogen model. The system consists of the density of the susceptible host, the density of the infected host, and the density of pathogen particles. Our main goal is to minimize the infected density and also to decrease the cost of the drugs administered. First, we prove the existence and uniqueness of solutions for the proposed problem. Then, the existence of the optimal control is established and necessary optimality conditions are also derived.

REGULATION OF β-CATENIN IN THE WNT SIGNALING PATHWAY AND EMT VIA OPTIMAL CONTROL

  • Sooyoun Choi;Il Hyo Jung
    • East Asian mathematical journal
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    • v.39 no.1
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    • pp.65-73
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    • 2023
  • In this paper, we present an optimal control strategy to prevent the EMT process by downregulating the level of overexpressed β-catenin in the cytoplasm. To do this, we propose a mathematical model that expresses relationship between the Wnt signaling pathway and TGF-β in cancer cells. We also define an optimal control problem considering the side effects that occur simultaneously with the method for controlling the concentration of β-catenin. Finally numerical simulations show that treatment effect is quantitatively changes depending on the concentration of core proteins of the Wnt signaling pathway.

Efficiency Optimization Control for Energy Saving of IPMSM Drive (IPMSM 구동의 에너지 절감을 위한 효율 최적화 제어)

  • 정동화;이정철;이홍균
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.12
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    • pp.697-703
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    • 2002
  • Interior permanent magnet synchronous motor(IPMSM) is widely used in many applications such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives. In order to maximize the efficiency in such applications, this paper is proposed the optimal control method of the armature current. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM The optimal current can be decided according to the operating speed and the load conditions. The proposed control algorithm is applied to IPMSM drive system, the operating characteristics controlled by efficiency optimization control are examined in detail by simulation.

Combined Optimal Design with Minimum Phase System (최소위상시스템을 고려한 통합최적설계)

  • 박중현
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.2
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    • pp.192-196
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    • 2004
  • A 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 the minimum weight design problem for the structure, but also the suppression problem of the effect of disturbances for the control system as the purpose of the design. A numerical example shows the validity of combined optimal design of the structure and control systems. We also consider the validity of the sensor-actuator collocation for the control system design in this paper.

An Experimental Study on an Optimal Controller for the Overhead Crane Using the Genetic Algorithm (유전자 알고리즘을 이용한 천정크레인의 최적제어기에 실험적 연구)

  • Choi, Hyeung-Sik;Kim, Kil-Tae
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.1 s.94
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    • pp.34-41
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    • 1999
  • This paper presents a HGA-based(hybrid genetic algorithm) optimal control strategy to control of the swing motion and the transfer of the overhead crane. The objective is to achieve the regulation of the fast swing motion or fast position control. The controller is based on the state feedback. The HGA-based optimal algorithm is applied to find optimal gains of the controller. Computer simulation and experiments were performed to demonstrate the effectiveness of the proposed control scheme.

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