摘要:

The problem investigated is that of minimizing an integral of the vth power of the magnitude of the system error, for a double-integrator plant with bounded control. It is known that the problem may be reduced by means of dimensional analysis to the determination of a single parameter in the control law. Methods of computing with high precision the optimal value of this parameter are studied in the present paper. It is also shown that for certain values of v the optimal controller becomes the same as the time-optimal controller.

ISSN:0020-7179    

DOI:10.1080/0020718508961110

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

An efficient and robust algorithm for computing multivariable root loci is proposed. This algorithm solves a set of characteristic equations by pivoting. The algorithm is based on Kuhn's algorithm for finding roots of a polynomial by pivoting. Some theoretical results which validate the algorithm are obtained and several examples are computed to show the efficiency of the algorithm.

ISSN:0020-7179    

DOI:10.1080/0020718508961111

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In this paper, a technique for balancing a system in a closed-loop fashion is developed. This technique is referred to as ‘LQG balancing’, for it assumes that the system to be balanced is closed up with a standard LQG feedback loop. This paper focuses on LQG balancing of symmetric passive systems; such systems are used to model large vibrating structures with collocated rate sensors and actuators. A balancing characterization of reciprocity, passivity and losslessness is provided. A new method for reducing both the plant and the LQG compensator is developed. It is shown, using a hyperstability argument, that the loop made up with the full plant and any reduced LQG compensator is stable and has acceptable feedback properties.

ISSN:0020-7179    

DOI:10.1080/0020718508961112

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

We study the harvesting of predators in a predator-prey system as an optimal control problem with the goal of maximizing the long-term average yield. We show that the maximum yield can not be greater than the largest constant-rate harvest for which the system has an equilibrium, provided the controlled system tends to an equilibrium or has a periodic solution. We also give some examples indicating practical strategies using either bang-bang or instantaneous harvests whose yields approach this maximum.

ISSN:0020-7179    

DOI:10.1080/0020718508961113

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The analysis of optimal control systems incorporating observers has been approached by the shifted Chebyshev series in this study. The method simplifies the system of equations into the successive solution of a set of linear algebraic equations. One example is illustrated, and only a small number of the Chebyshev polynomials is needed to obtain a very attractive and excellent result.

ISSN:0020-7179    

DOI:10.1080/0020718508961114

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The operational matrix of backward integration for the shifted Chebyshev polynomials is introduced in this study. The general expression of the shifted Chebyshev polynomial approximation for any two arbitrary functions is also presented. A linear time-varying optimal control system with a quadratic performance measure is solved by using the shifted Chebyshev polynomials. Only a small number of Chebyshev polynomials is needed to produce an excellent result, and the outcome is much better than the solution obtained by using the block-pulse function. So, computer memory capacity and computing time can be saved considerably.

ISSN:0020-7179    

DOI:10.1080/0020718508961115

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

An efficient algorithm for the transformation of the input-output model into the state-space model is presented. The algorithm is based on a direct connection of the model parameters in both spaces. This connection can be expressed by a recursive formula. To ensure the consistency of the formula, the parameters must be calculated in the correct sequence. This is achieved by using a corresponding index sequence table. The method requires only a small number of numerical operations, therefore the computational time is short and the effect of rounding errors on the accuracy is small. A comparison of the proposed algorithm with a usual one is also given and a numerical example is presented at the end.

ISSN:0020-7179    

DOI:10.1080/0020718508961116

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The problem considered is state estimation from observations which include forcing inputs as well as outputs. The joint-minimum-covariance estimates of forcing and state are derived, treating the forcing as deterministic but initially unknown. The modifications required to treat the forcing as stochastic, with prior estimate and covariance but no model for its evolution, are noted.

ISSN:0020-7179    

DOI:10.1080/0020718508961117

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In this paper a two-level hierarchical partially decentralized control for the optimal resource allocation is considered. It is assumed that the coordinator has available the information which has an essential meaning for the whole system, while the local controllers, some different, have more detailed information concerning the particular subsystems. The original problem statement is presented in which some elastic constraint of the control variable is proposed and used for coordination. Owing to this it is possible to decompose the calculations and to realize the decentralized optimal control. In the LQ case considered, all the optimal control laws take analytical form and the control law of the coordinator is certainly equivalent.

ISSN:0020-7179    

DOI:10.1080/0020718508961118

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Many recursive identification methods have been developed for on-line estimation of parameters in dynamical systems. Such methods can also be applied to data for off-line problems, usually by passing the data through the recursive identifier a few times. In this paper such an approach is discussed. Suppose that a recursive identification method is applied to a data string obtained by concatenation of the original finite-data record. It is proved that the recursive identification method will then converge to a (local) minimum of the off-line finite-data identification criterion. We also provide some arguments as to why recursive identification may be a competitive way of performing the minimization. When using the data more than once it is a priori not clear how to treat the initial values and the forgetting factor. The problem is investigated and comparisons are made with an off-line prediction error method. Practical experiments show that the execution time for a repeated recursive algorithm is less than or equal to that of the off-line algorithm, and that the obtained accuracies are comparable.

ISSN:0020-7179    

DOI:10.1080/0020718508961119

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor