• Title/Summary/Keyword: weighting optimization

Search Result 196, Processing Time 0.022 seconds

INDEFINITE STOCHASTIC OPTIMAL LQR CONTROL WITH CROSS TERM UNDER IQ CONSTRAINTS

  • Luo, Cheng-Xin;Feng, En-Min
    • Journal of applied mathematics & informatics
    • /
    • v.15 no.1_2
    • /
    • pp.185-200
    • /
    • 2004
  • A stochastic optimal LQR control problem under some integral quadratic (IQ) constraints is studied, with cross terms in both the cost and the constraint functionals, allowing all the control weighting matrices being indefinite. Sufficient conditions for the well-posedness of this problem are given. When these conditions are satisfied, the optimal control is explicitly derived via dual theory.

A tracking controller using multi-layered neural networks

  • Bae, Byeong-Woo;Jeon, Gi-Joon;Kim, Kyung-Youn
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1992.10b
    • /
    • pp.56-60
    • /
    • 1992
  • This paper addresses the problem of designing a neural network based controller for a discrete-time nonlinear dynamical system. Using two multi-layered neural networks we first design an indirect controller the weights of which are updated by the informations obtained from system identification. The weight update is executed by parameter optimization method under Lagrangian formulation. For the nonlinear dynamical system, we define several cost functions and by computer simulations analyze the control performances of them and the effects of penalty-weighting values.

  • PDF

Interative Feedback Tuning for Positive Feedback Time Delay Controller

  • Tsang Kai-Ming;Rad Ahmad B.;Chan Wai-Lok
    • International Journal of Control, Automation, and Systems
    • /
    • v.3 no.4
    • /
    • pp.640-645
    • /
    • 2005
  • Closed-loop model-free optimization of positive feedback time delay controllers for dominant time delay systems is presented. Iterative feedback tuning (IFT) is applied to the tuning of positive feedback time delay controller. Three experiments are carried out to perform the model-free gradient descent optimization. The initial controller parameters and duration in specifying the cost function are suggested. The effects of step size, filter function and time weighting function on the performance of the optimized controlled are given. Simulation and experimental studies are included to demonstrate the effectiveness of the tuning scheme.

An Application of ALM-BFGS Algorithm for the Optimum Section Design of Composite Breakwaters (ALM-BFGS 알고리즘을 이용한 혼성방파제의 최적단면설계에 관한 연구)

  • Seo, Kyung Min;Ryu, Yeon Sun;Ryu, Cheong Ro
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.12 no.1
    • /
    • pp.197-205
    • /
    • 1992
  • For the optimal design of composite breakwaters, a computer program PROCOBRA is developed using the combined ALM-BFGS algorithm. A model formulation for the section design optimization problem of composite breakwaters is proposed where a concept of subsectional weighting factors is introduced in the objective function. Usability of the program is verified through a numerical example. From the study, it is found that the ALM-BFGS method is reliable and can be effectively applied for the design optimization of coastal structures. Compared with conventional design process, it is proved that the economical design of composite breakwaters is possible.

  • PDF

Pareto optimum design of laminated composite truncated circular conical shells

  • Topal, Umut
    • Steel and Composite Structures
    • /
    • v.14 no.4
    • /
    • pp.397-408
    • /
    • 2013
  • This paper deals with multiobjective optimization of symmetrically laminated composite truncated circular conical shells subjected to external uniform pressure load and thermal load. The design objective is the maximization of the weighted sum of the critical buckling load and fundamental frequency. The design variable is the fibre orientations in the layers. The performance index is formulated as the weighted sum of individual objectives in order to obtain optimal solutions of the design problem. The first-order shear deformation theory (FSDT) is used in the mathematical formulation of laminated truncated conical shells. Finally, the effect of different weighting factors, length-to-radius ratio, semi-cone angle and boundary conditions on the optimal design is investigated and the results are compared.

Multiobjective optimum design of laminated composite annular sector plates

  • Topal, Umut
    • Steel and Composite Structures
    • /
    • v.14 no.2
    • /
    • pp.121-132
    • /
    • 2013
  • This paper deals with multiobjective optimization of symmetrically laminated composite angle-ply annular sector plates subjected to axial uniform pressure load and thermal load. The design objective is the maximization of the weighted sum of the critical buckling load and fundamental frequency. The design variable is the fibre orientations in the layers. The performance index is formulated as the weighted sum of individual objectives in order to obtain the optimum solutions of the design problem. The first-order shear deformation theory is used for the mathematical formulation. Finally, the effects of different weighting factors, annularity, sector angle and boundary conditions on the optimal design are investigated and the results are compared.

Optimal Design of Linear Quadratic Regulator Restrict Maximum Responses of Building Structures Subject to Stochastic Excitation (확률적 가진압력을 받는 건축구조물의 최대응답 제한을 위한 선형이차안정기의 최적설계)

  • 박지훈;황재승;민경원;조소훈
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 2001.09a
    • /
    • pp.373-380
    • /
    • 2001
  • In this research, a controller design method based on optimization is proposed that can satisfy constraints on maximum responses of building structures subject to ground excitation modeled by partially stationary stochastic process. The class of controllers to be optimized is restricted to LQR. Weighting matrix on controlled outputs is used as design variable. Objective function constraint functions and their gradients are computed parameterizing control gain with Riccati matrix. Full state feedback controllers designed by Proposed optimization method satisfy various design objectives and their necessary maximum control forces are computed fur the production of actuator. Probabilities of maximum responses match statistical data from simulation results well.

  • PDF

High-Efficiency Light-Weight Motor Design Technique for Electric Vehicle Using Evolution Strategy ((1+1) Evolution Strategy를 이용한 유도전동기의 최적 설계)

  • Kim, M.K.;Lee, C.G.;Park, J.T.;Lee, H.B.;Jung, H.K.;Hahn, S.Y.
    • Proceedings of the KIEE Conference
    • /
    • 1995.11a
    • /
    • pp.9-11
    • /
    • 1995
  • In this paper, tile squirrel case induction motors required multi-objective function are designed. As the objective function of the optimization program, we select the linear combination of loss and mass of motors by using weighting factors. Optimization process is performed by using the evolution strategy (ES). ES is the algorithm that can find the global minimum. To verify validity of the proposed method, a sample design is tried.

  • PDF

A Design Method for Direction Selective Structural-acoustic Coupled Radiator (구조-음향 연성현상을 갖는 방사 방향을 가질 수 있는 방사체 설계방법)

  • Seo, Hee-Seon;Kim, Yang-Hann
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.15 no.2 s.95
    • /
    • pp.225-231
    • /
    • 2005
  • This paper presents a design method for the structural-acoustic coupled radiator that can emit sound in the desired direction. A coupled system that has a finite space and a semi-infinite space separated by two flexible walls and an opening is considered. An objective function is selected to maximize radiation power on a main axis and minimize a side lobe level. To get initial values, prediction of a pressure distribution on field points and radiation pattern of the structural-acoustic coupling system is shown at a coupled-resonant frequency. Three different optimization methods are adapted to design the coupled radiator. Pressure and intensity distribution of the designed radiator is presented.

A Fuzzy Based Solution for Allocation and Sizing of Multiple Active Power Filters

  • Moradifar, Amir;Soleymanpour, Hassan Rezai
    • Journal of Power Electronics
    • /
    • v.12 no.5
    • /
    • pp.830-841
    • /
    • 2012
  • Active power filters (APF) can be employed for harmonic compensation in power systems. In this paper, a fuzzy based method is proposed for identification of probable APF nodes of a radial distribution system. The modified adaptive particle swarm optimization (MAPSO) technique is used for final selection of the APFs size. A combination of Fuzzy-MAPSO method is implemented to determine the optimal allocation and size of APFs. New fuzzy membership functions are formulated where the harmonic current membership is an exponential function of the nodal injecting harmonic current. Harmonic voltage membership has been formulated as a function of the node harmonic voltage. The product operator shows better performance than the AND operator because all harmonics are considered in computing membership function. For evaluating the proposed method, it has been applied to the 5-bus and 18-bus test systems, respectively, which the results appear satisfactorily. The proposed membership functions are new at the APF placement problem so that weighting factors can be changed proportional to objective function.