摘要:

In this paper second/third-order systems with time-dependont parameters which exhibit periodic or oscillatory response have been synthesized with a view to ascertaining the nature of variation of the system parameters. The analysis can easily be extended to cover other high-order systems as well. By judicious choice of the various arbitrary functions involved, many types of time dependent systems can be studied through the application of the method presentd here.

ISSN:0020-7179    

DOI:10.1080/00207176808905670

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The dynamic performance of many physical systems is adequately described by an ordinary linear differential equation of the form:where x(t) is the forcing function or the input to the system and y(t) is the response on the output of the system. If the coefficients ai, referred to as the parameters of the system, are known then the system is said to be completely known. In this investigation a method is suggested to evaluate these coefficients by performing measurements on the input and output of the system.

ISSN:0020-7179    

DOI:10.1080/00207176808905671

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Many feedback control system designs require the availability of the state of the controlled plant. Since the plant state variables are not generally available for direct measurement in practice a means for estimating these variables is required. Attention is restricted to plants which are linear, time-invariant, finite-dimensional, dynamic systems in this paper. In this case, necessary and sufficient conditions are derived for which a dynamical observer can be employed to estimate the plant state variables. An observer which satisfies these conditions is said to be compatible. When a compatibly observer is employed, and when the plant input vector is made equal to a linear, time-invariant, matrix multiplication on the estimated plant state vector, it is shown hero that the eigenvalues of the overall system can be made equal to any desired values (complex eigenvalues occurring in conjugate pairs) provided the plant is completely controllable. In particular, the plant can always be stabilized.

ISSN:0020-7179    

DOI:10.1080/00207176808905672

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The paper presents an extension of Popov's frequency domain stability criterion to quasi-asymptotic stability of a class of systems involving both distributed as well as lumped elements and one bounded non-linear element. The results are presented in the form of a theorem to cover plants which may include a pure integration as well as direct transmission. Through a computer-derived transformation of the classical Popov plot, a simple interpretation of the new theorem for quasi-asyinptotic stability is given. It is shown that significant improvement in maximum allowable gain is obtained over the Popov value for a system not satisfying Aizerman's conjecture.

ISSN:0020-7179    

DOI:10.1080/00207176808905673

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

An adjoint variable technique is developed which simplifies the calculation of the second derivatives of an error index with respect to parameters and initial states. The adjoint variable technique requires the numerical integration of only a fraction of the number of equations required by existing techniques.

ISSN:0020-7179    

DOI:10.1080/00207176808905674

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

In this paper, a now approach to the study of systems with variable parameters, has been presented. The method while being applicable in general to any system wherein the derivatives of the time dependent parameters are expressible in terms of variable parameter itself, is of particular value in the study of systems with periodically varying parameters.

ISSN:0020-7179    

DOI:10.1080/00207176808905675

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

A now procedure for the synthesis of a control law for the stabilization of spacecraft angular velocity is presented. This control law approximately minimizes both the time required to drive the angular velocity of the spacecraft to zero and the integral of the square of the norm of the angular momentum. Synthesis of the control law in feedback form is discussed. In a computer simulation, results obtained by use of the proposed control are shown to compare favourably with those obtained by use of the optimal control.

ISSN:0020-7179    

DOI:10.1080/00207216808905676

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

This paper extends the notion of absolute stability to include the parameter variations of the linear part of the system. A simple analytic procedure is proposed to calculate the regions of absolute stability in the parameter space. then, a parallelepiped of maximum volume is embedded in the region to interpret its boundaries and obtain readily the information about parameter variations which do not affect the system stability.

ISSN:0020-7179    

DOI:10.1080/00207176808905677

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

In many complex control processes, the problem of determining optimal control policies can be considerably simplified from the stand-points of computation and implementation, if the mathematical model can be adequately described by a finite-state sequential system, i.e. a discrete-time system whose input (control) and state spaces are finite-state. However, in physical situations, one usually formulates the mathematical models in the form of a set of ordinary differential equations resulting from certain physical laws. Therefore, it is desirable to have systematic methods far approximating such mathematical models by finite-state systems.

ISSN:0020-7179    

DOI:10.1080/00207176808905678

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The problem considered in this paper is that of designing an attitude regulator for an arbitrary rigid body. The design criterion is that, in the presence of no disturbance torques on the body, the system should have only one equilibrium point, and this point should be asymptotically stable for arbitrary initial conditions. By use of Lyapunov techniques and an appropriate choice of state variables, it is shown that this criterion can be satisfied by employing a linear feedback law with constant coefficients.

ISSN:0020-7179    

DOI:10.1080/00207176808905679

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor