摘要:

The design of delayed control systems is considered. Zakian's method is described and applied to practical systems. The results are compared with those of conventional techniques based on the Ziegler and Nichols method.

ISSN:0020-7179    

DOI:10.1080/00207178408933306

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper deals with the design of optimal discrete control systems with prescribed eigenvalues. Solheim's method for such design is improved and extended to achieve the original design objective. That is the minimization of a quadratic performance index with a prescribed control weighting matrixRand some state weighting matrixQ. A new recursive algorithm is also presented. While this algorithm retains the simplicity provided by Solheim's method, it constructs the resultant state weighting matrix Q as the sum of the recursive state weighting matrices <?(. The algorithm is general and applicable to any system structure. For the sake of completeness, the optimality of Solheim's solution is tested by using a simple necessary condition which is developed in the paper. It is shown that the optimality of Solheim's solution is not. in general, guaranteed.

ISSN:0020-7179    

DOI:10.1080/00207178408933307

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A new approach for microprocessor implementation is introduced for simultaneous control of the attitude and a number of flexure modes, assuming a lumped parameter dynamics model and control actuators mounted on a central rigid body. The switching times of the bang-bang control to be applied are calculated as a function of the current state estimate so as to render the control system performance almost independent of the microprocessor iteration interval. The control law is applicable where the modes are of arbitrarily low frequency so that the current trend of increasing size of spacecraft structures does not impose a limitation. The approach is naturally suited to gas jet actuators, but is also applicable with continuous actuators such as reaction wheels, in which case control torque saturation limits are automatically considered and the effects of bearing stiction reduced by means of the control dither produced during the limit cycle. Attention is restricted at present to control of a single axis, three-axis control with inter-axis coupling requiring a multivariable extension of the principle. At present, initial conditions must be within a certain neighbourhood of the state origin, but developments of the control principle are envisaged which will remove this restriction. Simulation results are presented of a single-axis control with up to three modes and various combinations of frequency.

ISSN:0020-7179    

DOI:10.1080/00207178408933308

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper deals with the problem of optimally controlling traffic flows in urban traffic networks. For this, a nonlinear discrete-time model of an urban traffic network is first suggested in order to handle the phenomenon of traffic flows such as oversaturatedneas and undersaturatedness. Then an optimal control problem is formulated and a hierarchical optimization technique is applied, which is based on a prediction-type two-level method of Hirvonen and Hakkala.

ISSN:0020-7179    

DOI:10.1080/00207178408933309

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

It is first demonstrated that every LQG optimal control problem can be rewritten as a minimum output variance control problem for a related system model. This system may be defined in either minimum or non-minimum phase forms. The optimal controller derived from the equivalent minimum variance problem is identical to the LQG optimal controller. During the solution of the equivalent problem an equation is derived which is similar to the implicit relationships used in direct self-tuning control schemes. This enables the problems in constructing a multivariable implicit LQG self-tuning controller, using polynomial matrix methods, to be explored. The inherent difficulties become clear but a possible strategy is evident. Finally the results are specialized to the scalar case and a very simple implicit LQG self-tuning algorithm is described.

ISSN:0020-7179    

DOI:10.1080/00207178408933310

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A design method of an output feedback control system is proposed on the basis of an improved optimal regulator technique and application of the method to an electrical drive system is presented. The control system structure of the output feedback control system is clarified by comparing it with that of the full state variable feedback control system synthesized by the improved optimal regulator technique. Difference action as well as proportional and integral actions are included in the controller of the output feedback control system, on the other hand, only proportional action and integral action are introduced in the controller of the full state feedback control system. Low static sensitivity for variations of the parameters of the controlled object is attained, and the compensating action for the input delay times due to the processing time required to execute the employed control algorithm with the microprocessor are also taken into account.

ISSN:0020-7179    

DOI:10.1080/00207178408933311

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The problem of discrete system stability when the coefficients of the characteristic polynomial are allowed to vary independently, is considered. A sufficient condition is given to guarantee system stability under such coefficient variations. The non-conservativeness of this condition is demonstrated by two examples.

ISSN:0020-7179    

DOI:10.1080/00207178408933312

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0020-7179    

DOI:10.1080/00207178408933313

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This note presents two absolute stability theorems which arc versions for discrete-time systems of a theorem by S. K. Persidskii (1969).

ISSN:0020-7179    

DOI:10.1080/00207178408933314

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The necessary and sufficient condition for decoupling through linear state variable feedback (l.s.v.f.) alone presented by Moness and Lantos (1984) is incorrect. This condition is equivalent to the sufficient condition proposed by Vardulakis (1981).

ISSN:0020-7179    

DOI:10.1080/00207178408933315

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor