摘要:

Rosenbrock's inverse Nyqviist array design method for continuous multivariable systems is extended to the design of multivariable sampled-data systems. The effects of sampling and incorporating zero-order holds in the system are shown to play important roles in the design procedure. A design example is presented to illustrate the approach developed, and the results obtained are compared with previous work.

ISSN:0020-7179    

DOI:10.1080/00207177508922086

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Model reference adaptive controllers for multivariable plants are designed using only input and output signals rather than the complete state vector. The design is based on Liapunov's direct method, and the Meyer-Kalman-Yacubovich lemma. State variable filters are employed to avoid differentiating output signals. Augmented error signals are used in deriving stable adaptive control laws which assure that the normally used response error signals approach zero asymptotically.

ISSN:0020-7179    

DOI:10.1080/00207177508922087

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A control method is proposed which permits the application of the relatively simple time-optimal feedback control laws for the double and triple integrator plants to a wide range of more general second and third-order plants having real non-positive eigenvalues. The method, which is based on a state-variable transformation technique, gives time-optimal control for certain plants with eigenvalues in a simple ratio. In other cases the control is sub-optimal and yields settling times typically within 2% and 4% of the corresponding optimal value3 for second and third-order plants, respectively. Thus one may avoid the difficulty of synthesizing- the logarithmic, exponential or other complicated functions of state variables which are generally present in the exact time-optimal control laws (where known) for such plants.

ISSN:0020-7179    

DOI:10.1080/00207177508922088

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Signal aliasing in the digital identification of continuous systems is considered. Parametric identification methods are seen to be free of aliasing errors, provided that the poles of the continuous system are known to lie in specific s-plane regions. In the case of non-parametric identification, frequency response estimates based upon digital techniques are shown to be seriously distorted by signal aliasing. In particular, aliasing errors are shown to be phase sensitive and can therefore be controlled by suitable equalization of the relative phase of observed input-output signals.

ISSN:0020-7179    

DOI:10.1080/00207177508922089

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The design of linear controllers of reduced dimensions, which are to be used for the regulation of a class of linear stochastic systems, is dealt with. A modified quadratic performance criterion is employed in which a quadratic penalty on the system and controller states as well as on all controller gain matrices is used. Both the finite terminal time and the steady-state versions of the problem are treated, For the latter case an efficient way of deriving optimality conditions is used. For the finite terminal time problem a two-point boundary value problem whose solutions are the gain matrices of the controller is derived. For the steady-state case, two non-linear matrix algebraic equations must be solved to implement the low-order controller.

ISSN:0020-7179    

DOI:10.1080/00207177508922090

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A method is presented to place a number of system eigenvalues by means of output feedback, and to use any remaining design freedom to minimize a specified performance functional. The solution for this combination of optimal control and pole assignment is shown to be similar to that for the complete state feedback case and uses a novel pole assignment algorithm.

ISSN:0020-7179    

DOI:10.1080/00207177508922091

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

An engineering solution to the problem of approximating a high-order linear system by a low-order model is suggested, which consists in formulating a quadratic error functional as a basic tool for the construction of a physically transparent and practically meaningful approximation criterion. For various different modes of operation analytical expressions for the evaluation of the functional as well as the gradients with respect to the unknown model parameters are given, which allows known gradient techniques to be applied for finding the optimal model parameters. In addition a representation for a general multivariate model, using only the minimal number of unknown parameters, is given.

ISSN:0020-7179    

DOI:10.1080/00207177508922092

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Techniques for estimating the initial conditions of deterministic and stochastic linear systems are presented and investigated. Difficulties in implementation of existing and proposed algorithms for initial condition estimation are noted and methods for overcoming these difficulties are formulated.

ISSN:0020-7179    

DOI:10.1080/00207177508922093

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This paper presents a method for assessing the sensitivity of the output of a linear time-invariant system to changes in the state variables, which in a sense is an assessment of the degree of observability of the system. The system equations are transformed to a canonical form and a ‘ modal observability-matrix ’ defined, the columns of which indicate the relative degree by which each mode of the system is observed. Methods of scaling the modal-observability-matrix to give more meaningful results are discussed and realistic examples are given.

ISSN:0020-7179    

DOI:10.1080/00207177508922094

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The design of an optimal controller for a discrete-time single-input, single-output system is well documented in a number of textbooks (e.g. Bryson and Ho 1969). It has been shown by Hem (1969), using a procedure similar to that proposed by Lee (1964), and later by Bryson and Ho. that the optimal controller may be represented by its z-transfer function and therefore may be simply implemented as the ratio of two polynomials in z−1, thus reducing appreciably the amount of on-line computation. Unfortunately, the method of Lee for the computation of the coefficients of the z-transfer function has been found to break down when the structure of the plant includes a finite time delay which creates a singularity in the plant transition matrix. In this paper it is shown that the existence of the singularity induces an orthogonality in the structure of the optimal controller equations which invalidates the application of Lee's method. An alternative, computationally robust, technique is presented for the computation of the coefficients of the z-transfer function of the optimal controller.

ISSN:0020-7179    

DOI:10.1080/00207177508922095

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor