Notification:
We are currently experiencing intermittent issues impacting performance. We apologize for the inconvenience.
By Topic

Automatic Control, IEEE Transactions on

Issue 1 • Date February 1975

Filter Results

Displaying Results 1 - 25 of 60
  • [Front cover and table of contents]

    Publication Year: 1975 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (197 KB)  
    Freely Available from IEEE
  • Comments on "Estimation in linear delayed discrete-time systems with correlated state and measurement noises"

    Publication Year: 1975 , Page(s): 176 - 177
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (193 KB)  

    In a recent paper, equations were derived for the state estimation and the error covariance of a linear discrete-time delayed system involving correlated noises. However, there appears to be a fundamental mistake in the procedure given and this is corrected. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "A simplification of Jury's tabular form

    Publication Year: 1975 , Page(s): 177 - 178
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Author's reply

    Publication Year: 1975 , Page(s): 178
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    The author thanks Dr. Jury for his comments. The auxiliary constraints, based on evaluation of F(1) and F(-1), can be used to shorten the necessary computation, particularly in the singular cases. (In the nonsingular case, evaluation of F(1) and F(-1) is comparable to the steps saved in the tabular form.) It is to be noted, however, that the simplicity of the proposed method and the directness with which results are presented lend themselves to the assimilation of the auxiliary constraints and any other information incidental to a specific problem into the analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "On the Routh-Hurwitz criterion"

    Publication Year: 1975 , Page(s): 178 - 179
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (153 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Author's reply

    Publication Year: 1975 , Page(s): 179
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (84 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Author's reply

    Publication Year: 1975 , Page(s): 180
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "On the simplification of linear systems"

    Publication Year: 1975 , Page(s): 180 - 181
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (167 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Author's reply

    Publication Year: 1975 , Page(s): 181
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (98 KB)  

    The author appreciates very much the comments on his work and the commenter's supplement of other important references related to the subject of system order reduction. With respect to the comment on the physical basis of the criterion he describes, the author maintains he has clearly stated in his article that the criterion is based on the philosophy that the low order model L(s) is chosen to approximate the frequency response of the higher order system H(s). On the point of using a vector criterion instead of a scalar criterion, there is no doubt that the former is, in theory, more powerful than the latter. However, the former may easily lead to optimization problems which are more difficult to solve. The author fully agrees with the commentor's view that the "best model" is highly dependent on the specific application involved. Therefore, a more logical way for obtaining a specific model is to incorporate into the simplification criterion, a priori, elements measuring the performance of the resulting overall system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • [Back cover]

    Publication Year: 1975 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (493 KB)  
    Freely Available from IEEE
  • Generalization of Leverrier's algorithm to polynomial matrices of arbitrary degree

    Publication Year: 1975 , Page(s): 136
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    Leverrier's algorithm to find the determinant of ( sI_{r}-A ) is generalized to the polynomial matrices of arbitrary degree which are in the form I_{r}s^{n} + H_{n-1}s^{n-1} + ... + H_{1}s + H_{0} . View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inner algorithm to test for positive definiteness of arbitrary binary forms

    Publication Year: 1975 , Page(s): 169 - 170
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    It is shown how the test for positive definiteness of an arbitrary binary form can be expressed in terms of an inner algorithm. An example is used to illustrate the computational aspects of the procedure. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Geometric interpretation of complex vectors arising in the frequency-domain analysis of multivariable systems

    Publication Year: 1975 , Page(s): 157 - 158
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    It is shown that an n -dimensional vector whose components are complex numbers can be visualized as a plane ellipse in geometric n -space. The length and direction of a complex vector are interpreted in terms of the ellipse axes thus giving a deeper insight into the eigenstructure of system transfer matrices. The system characteristic ellipse is introduced and its application to the measurement of characteristic loci is discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the calculation of the transfer function matrix

    Publication Year: 1975 , Page(s): 134 - 135
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB)  

    Given the state space realization {A,B,C} of a linear time-invariant multivariable dynamic system, a computational algorithm for calculating elements of the corresponding transfer function matrix is presented. The algorithm neither requires cofactor calculation, nor applies any state transformation. The only requirement is calculation of the coefficients of characteristic equations of given matrices. Also, the Fortran subroutine based on the presented algorithm is included. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Singular perturbations of a class of time-optimal controls

    Publication Year: 1975 , Page(s): 163 - 164
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    An approximate time-optimal control of a linear time invariant system consisting of a cascade of fast and slow subsystems is proposed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Least squares simulation of distributed systems

    Publication Year: 1975 , Page(s): 75 - 83
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    This paper addresses the application of linear optimal control theory to the least squares functional approximation of linear initial-boundary value problems. The method described produces the optimal approximate solution by the realization of a linear quadratic servo configuration imposed on the Galerkin simulation for the problem. It is shown that appropriate formulation of the servo problem guarantees a stable numerical solution, even when the Galerkin simulation itself is unstable, a situation not uncommon with certain hyperbolic partial differential equations. Theoretical least squares and Galerkin properties are comparatively discussed, and numerical examples demonstrating least squares convergence in the face of Galerkin divergence are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Formulation of a definite class of Lyapunov functions

    Publication Year: 1975 , Page(s): 174 - 176
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    The process presented in this correspondence will generate a Lyapunov function with a negative-definite time derivative for all systems in phase variable form which satisfy the conditions of Lyapunov's first method and one extra continuity condition. For an n th-order system, in order to determine a set of n - 1 constants, the method requires a calculation of one inverse of a matrix which is related to the Routh-Hurwitz matrix. The remainder of the constants and the desired Lyapunov function are found by using recursive formulas. Except when the inverse does not exist, the method generates a scalar function which will determine instability by Chetaèv's theorem for those systems where the first method applies. The process is then extended to the case where the first method fails. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Sensitive decoupling control of linear disturbed-parameter systems

    Publication Year: 1975 , Page(s): 151 - 153
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    The input-output decoupling control problem for a generalized multivariable linear model, covering most practical situations, is treated for the case where the model involves disturbances in the parameters. A sensitive decoupling controller is derived which maintains the decoupling conditions to first order in the parameter variations, about their nominal values. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of optimum feedback gains for output-constrained regulators

    Publication Year: 1975 , Page(s): 164 - 166
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB)  

    The problem of numerical calculation of optimal output-constrained feedback regulators is considered. A new sequential computational procedure yields the regulator solution in several steps. The number of steps depends on the difference between the dimensions of the state and output vector. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Superiority of transfer function over state-variable methods in linear time-invariant feedback system design

    Publication Year: 1975 , Page(s): 84 - 97
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1536 KB)  

    The objectives and achievements of state-variable methods in linear time-invariant feedback system synthesis are examined. It is argued that the philosophy and objectives associated with eigenvalue realization by state feedback, with or without observers, are highly naive and incomplete in the practical context of control systems. Furthermore, even the objectives undertaken have not really been attained by the state-variable techniques which have been developed. The extremely important factors of sensor noise and loop bandwidths are obscured by the state-variable formulation and have been ignored in the state-variable literature. The basic fundamental problem of sensitivity in the face of significant plant parameter uncertainty has hardly received any attention. Instead, the literature has concentrated primarily on differential sensitivity functions and even those results are so highly obscured in the state-variable formation as to lead to incorrect conclusions. In contrast, the important practical considerations and constraints have been clearly revealed and considered in the transfer function formulation. Differential sensitivity results are simple and transparent. For single input-output systems, there exists an exact design technique for achieving quantitative sensitivity specifications in the face of significant parameter uncertainty, which is optimum in an important practical sense. This problem is much more difficult and has not been completely solved for multivariable systems, but it has at least been realistically attacked by some transfer function methods. Finally, the concepts of controllability and observability so much emphasized in the state-variable literature are examined. It is argued that their importance in this problem class has been greatly exaggerated. On the one hand, transfer function methods can be used to check for their existence. On the other hand, nothing is lost when they are ignored, if the synthesis problem is treated as one with parameter uncertainty by transfer function methods. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Differential controllability and the solution of linear inequalities--Part I

    Publication Year: 1975 , Page(s): 128 - 131
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    Two characterizations of differentially controllable linear autonomous systems for which the origin is assumed to be a boundary point of the control restraint set are presented. These characterizations extend well-known results which contain the assumption that the origin is interior to the control restraint set. These characterizations are given in terms of the system matrix and the control restraint set. The first theorem applies to arbitrary restraint sets, while the second is restricted to polyhedral regions. The second characterization is the basis for a computational algorithm for the determination of differential controllability to be described in a future paper. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some notes on the inversion of confluent Vandermonde matrices

    Publication Year: 1975 , Page(s): 154 - 157
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (272 KB)  

    The determination of the inverse of the confluent Vandermonde matrix stood often in the focus of attention. To achieve this aim many methods were elaborated. Based on the Leibniz rule of derivation, in this correspondence the elements of the inverse confluent Vandermonde matrix are computed, and, at the same time, a common explanation is given for the various methods seeming at the first sight quite different. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the computation of optimal stochastic observer gains

    Publication Year: 1975 , Page(s): 145 - 146
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    The design of a reduced-order continuous-time optimal stochastic observer has been based on the solution of a full-order covariance equation which restricts the implementation benefits of the reduced-order estimator. In this correspondence, it is shown that the gains of the reduced-order observer can be obtained by solving a reduced-order covariance equation, thus gaining the benefits of the reduced-order estimator. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved convergence of Lyapunov model reference adaptive systems by a parameter misalignment function

    Publication Year: 1975 , Page(s): 132 - 134
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    A modified approach is presented for the design of Lyapunov model reference adaptive systems. The approach introduces the use of a function of the parameter misalignment, which can be generated with minor demands for additional hardware. Simulation confirms the acceleration in convergence of the system error compared to previous design procedures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An upper bound on the product of eigenvalues of an optimal linear system

    Publication Year: 1975 , Page(s): 162 - 163
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    Explicit relations between the weighting factors of a quadratic performance criterion and the closed-loop system are developed. A best possible upper bound on the product of the eigenvalues of the closed-loop system is attained. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

In the IEEE Transactions on Automatic Control, the IEEE Control Systems Society publishes high-quality papers on the theory, design, and applications of control engineering.  Two types of contributions are regularly considered

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
P. J. Antsaklis
Dept. Electrical Engineering
University of Notre Dame