摘要:

AbstractIn controlling distributed parameter systems it is often desirable to obtain low‐order, finite‐dimensional controllers in order to minimize real‐time computational requirements. Standard approaches to this problem employ model/controller reduction techniques in conjunction with LQG theory. In this paper we consider the finite‐dimensional approximation of the infinite‐dimensional Bernstein/Hyland optimal projection theory. Our approach yields fixed‐finite‐order controllers which are optimal with respect to high‐order, approximating, finite‐dimensional plant models. We illustrate the technique by computing a sequence of first‐order controllers for one‐dimensional, single‐input/single‐output parabolic (heat/diffusion) and hereditary systems using a spline‐based, Ritz‐Galerkin, finite element approximation. Our numerical studies indicate convergence of the feedback gains with less than 2% performance degradation over full‐order LQG controllers for the parabolic system and 10% degrad

ISSN:0143-2087    

DOI:10.1002/oca.4660110102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper presents an application of the maximum principle and the generalized maximum principle (a recent extension of that principle) to a discrete‐time model of consumer choice behaviour. The model includes two brands in a market and uses a non‐stationary first‐order Markov chain. The optimization is carried out by algorithms based on the above mentioned principles. These algorithms are described, and their performances are discussed and compared both with and without fulfilment of the directional convexity pro

ISSN:0143-2087    

DOI:10.1002/oca.4660110103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe existence of a (global) optimal controlu* is established which ensures the execution of a constant‐altitude, minimum‐time flight trajectory to a specified fly‐to point, given the aircraft maximum performance turn radius and the wind speedWand direction tHw. Fast, accurate numerical procedures based on elementary geometry and the solution of a fixed‐point equation are derived for the calculation ofu* and the associated optimal trajectory (x*,y*). An example is given and the application of these results to the real‐time solution of the case where the aircraft roll rate is also incorporated into the flight dynamics is

ISSN:0143-2087    

DOI:10.1002/oca.4660110104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe design of a low‐order dynamic output feedback controller for a flexible spacecraft is carried out using modified linear quadratic Gaussian (LQG) theory. The necessary conditions for optimization are given. The linear equations governing a flexible spacecraft with a central rigid body and two sun‐tracking solar panels are presented. The parameters of the Solar Electric Propulsion Spacecraft (SEPS) are selected for analysis and simulation. The optimal gains for the dynamic controller are estimated using an iterative algorithm. The sequential procedure which assures convergence is selected. The initial gains which stabilize the system are chosen on the basis of the principle of a PD controller. A third‐order controller for pitch, roll and yaw axes of the 18th‐order system, which includes sensor and actuator dynamics, is designed. Numerical simulations carried out to ascertain the performance of the controller show the performance to be satis

ISSN:0143-2087    

DOI:10.1002/oca.4660110105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe following problem is discussed: given an optimal control law for a linear, discrete‐time, single‐input system with respect to some quadratic cost, determine the necessary and sufficient condition whereby this control law remains optimal in the presence of small plant parameter variations. This condition is derived and expressed in terms of the loop transfer function of the optimal system, its Nyquist plot and the transfer function from the input to the controlled variables associated with the weighting mat

ISSN:0143-2087    

DOI:10.1002/oca.4660110106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractAn improved singular perturbation method for the singularly perturbed, closed‐loop discrete optimal control problem with two terminal boundary layer correction series is presente

ISSN:0143-2087    

DOI:10.1002/oca.4660110107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractAn optimal stopping‐time problem for a diffusion process absorbed at the boundary of a bounded domain inRd(d le 1) is considered. The cost criterion is of time‐average type and may be regarded as a version of the Gittins index. We characterize the value function and construct an optimal stopping policy using dynamic programming. Two numerical algorithms are used to solve two test problems inR1an

ISSN:0143-2087    

DOI:10.1002/oca.4660110108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis communication presents computational results with a variant of differential dynamic programming. The class of methods is motivated by quasi‐Newton methods and constructs quadratic approximations by using stagewise gradients. We compare two methods of updating the approximations: the first is based on the symmetric Broyden update and the second is a sequential rank‐one/rank‐two update. Our computational results suggest that the latter is a practical and efficient algorithm for discrete‐time optimal

ISSN:0143-2087    

DOI:10.1002/oca.4660110109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe ripple‐free deadbeat control problem for SISO plants subjected to arbitrary reference signals is considered. The trade‐off between the settling time and the integral square error between the system output and reference signal is investigated. Given a specific order of the controller, it is shown how to design an optimal ripple‐free deadbeat controller. An illustrative example is presented to show the feasibility of the proposed algo

ISSN:0143-2087    

DOI:10.1002/oca.4660110110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0143-2087    

DOI:10.1002/oca.4660110101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY