摘要:

This paper describes the application of the diesel engine models, in speed control studies, which were developed in the authors' previous paper. Particular emphasis is placed on the 2-transform techniques for investigating the time domain of the various system models. The work reveals the necessity for the development of these engine models for use in the study of systems with the electronic governors now becoming available.

ISSN:0020-7179    

DOI:10.1080/00207177108931971

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A sampled-data model of a spark-ignition engine, when used in essentially constant-speed situations, is developed. This has resulted in the discussion of an unusual type of control element termed an ‘integrate, sample and cancel circuit’. Some properties of this type of element are demonstrated. A comparison is made between this model and the model for diesel-engine control studies previously developed by the authors.

ISSN:0020-7179    

DOI:10.1080/00207177108931972

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This paper deals primarily with the stability criteria for closed-loop systems whose controlled plants comprise a proportional, single integration, or double integration characteristic, together with a true time-delay. These plants are considered in turn to be controlled by simple proportional, lead or lag controllers.

ISSN:0020-7179    

DOI:10.1080/00207177108931973

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This paper presents a systematic method of developing all the possible configurations for the assumed sinusoidal input to the sampler, as the lag varies between 0°and 360°and for the output of the zero-order hold following a relay with dead zone. Any period of oscillation characterized by a different number of positive and negative relay corrections can be considered. The equivalence of the critical regions for different periods of oscillation is pointed out. The critical points on the waveform at which either a relay correction or an entry into the dead zone can occur are precisely determined. Further the critical instants of sampling during a period of oscillation are also clearly established with the result that the development of the critical regions is made much easier. The meeting of the maxima and minima of two different critical regions is indicated, thus aiding in the correct development of the critical regions. The size of the area of different critical regions for the same period of oscillation and the total number of critical regions obtainable for any period of oscillation are discussed. The critical regions are developed for the periods of oscillation of 9T through 20T based on the above considerations. These critical regions together with the recently reported result in respect of an odd period of oscillation are made use of to identify all the possible modes that can be sustained in a second-order system with transportation lag and a third-order system. Thus the utility of the discrete describing function is considerably enhanced.

ISSN:0020-7179    

DOI:10.1080/00207177108931974

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A general series expansion is derived for the amplitude of any modulation component in the output of a single-valued non-linearity subjected to an input which is the sum of any number of cosine waves of different frequencies. An important property of this expansion is that it expresses the response of the non-linearity to a multiple cosine wave input in terms of its response to a single cosine wave input; thus an inter-modulation component or a Multiple Input Describing Function (MIDF) can be obtained by using the coefficients of the Fourier series expansion of the output of the non-linearity when the input is a single cosine wave of appropriate amplitude. Since these coefficients can also be obtained by measurements, the method may be applied directly to empirical non-linearities without resorting to piecewise linear or polynomial approx imations.

ISSN:0020-7179    

DOI:10.1080/00207177108931975

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A chain of factored matrices is derived for formulating the Routh array if the first column of the array is known. The factored matrices may be used to perform the conversion of a continued fraction into a rational function. A set of tables based on the second Cauer form of continued fraction expansion is also included. These tables are the approximated rational functions for the commonly used irrational function √ and the transcendental functiones.

ISSN:0020-7179    

DOI:10.1080/00207177108931976

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Sufficient conditions are given for the existence of non-trivial periodic solutions for the equation of a class of time-invariant, non-linear feedback systems. The criteria rely on familiar principles in topology and are presented in such a form that they constitute an oscillation counterpart of Popov's stability theorem.

ISSN:0020-7179    

DOI:10.1080/00207177108931977

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This paper studies the design of series compensators necessary for decoupling of multivariable systems possessing weak inherent coupling by state feedback. An alternate characterization of weak inherent coupling is given in the form of an algorithm which plays a key role in deriving the properties and the general solution for the parameters of the compensator. A method of synthesis, which introduces the minimum number of dynamic elements in the compensator and places all its poles at the origin of the complex frequency plane, is given.

ISSN:0020-7179    

DOI:10.1080/00207177108931978

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This paper considers the optimization of time-varying multivariable control systems with quadratic cost function which may have time-varying weighting matrices. The problem is first formulated in the context of functional analysis which leads to the optimal control being denned by a functional equation. An approximate solution of this equation is then obtained by replacing the kernel of the equation by a double Fourier series expansion. It is shown that the resulting sub-optimal control may be made to approach the absolute optimum as closely as desired by extending the double Fourier series, and bounds on the norm of the error in the control and the cost function are derived for any finite expansion. Application of the method to a particular system shows that Chebyshev basis functions lead to a better approximation than the classic sinusoidal functions. Finally, the use of the method as an adjunct to iterative optimization based on the contraction mapping algorithm is discussed briefly.

ISSN:0020-7179    

DOI:10.1080/00207177108931979

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

For a second-order all-pole transfer function, the maximum overshoot of the step response is the same for all poles lying on the same radial line. Therefore the radial lines themselves are contours of equal maximum overshoots. With a negative real zero introduced into this transfer function, the overshoot contours are different from the radial lines of the all-pole case. These modified contours are presented in this article.

ISSN:0020-7179    

DOI:10.1080/00207177108931980

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor