摘要:

The design equations and the approach of a technique for the classical design of 3×3 systems are improved and simplified. The equations are also formulated for plant transfer matrices derived from state models, with separate allowance for incorporating sensor and actuator dynamics. This formulation is applied to an IFAC theme problem on the control of an F 100 turbofan engine model.

ISSN:0020-7179    

DOI:10.1080/00207178708933706

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Chaotic behaviour due to round-off characteristics in digital compensators is called a chaotic rounding error. First, we show sufficient conditions for the existence of chaotic rounding errors in digital control systems with first-order plants and first-order finite-wordlength compensators. Next, it is shown that a chaotic rounding error, which appears as a chaotic attractor in the state space, can be described by a Markov chain with an appropriate partition of the attractor. Finally, by analysing the Markov chain we calculate several statistical properties of the chaotic rounding error.

ISSN:0020-7179    

DOI:10.1080/00207178708933707

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The behaviour ofn-inputn-output systems with white noise is considered. An adaptive controller that simultaneously decouples the system and assigns its closed-loop poles is derived. This controller is of the ‘hybrid’ type and consists of a continuous-time control law, the parameters of which are updated using a discrete-time identification algorithm. Convergence and strong consistency results are derived for the identification algorithm and used to demonstrate that the adaptive control law does indeed produce a stable decoupled closed-loop system with correctly assigned poles.

ISSN:0020-7179    

DOI:10.1080/00207178708933708

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In this paper, we consider the state and free boundary estimation problems for stochastic two-phase Stefan systems. First, the existence and uniqueness properties of the solution to the state equation with white noise coefficients are discussed by using the finite difference method with respect to time and spatial variables. Secondly, the state and free boundary estimator dynamics are derived by using martingale representation theory. Finally, representative sample runs obtained by digital simulation experiments are shown, including a simple approximation method for realizing non-linear estimator dynamics.

ISSN:0020-7179    

DOI:10.1080/00207178708933709

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In the research reported here, a method of coefficient assignment for single-input time delay systems is given using a Wolovich type compensator structure (frequency domain). Using some basic notions of polynomials in two variables, the set of compensators that will allow coefficient assignment can be completely characterized in a simple and explicit fashion. Both full-order and reduced-order compensators can be characterized. It is possible to reinterpret the results from a state-space point of view.

ISSN:0020-7179    

DOI:10.1080/00207178708933710

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Traditionally, PI controllers operate solely on the reference error signal (modified reference error in the case of PID controllers) in the forward path of the classical feedback loop. They are designed either as regulating (e.g. to reduce process disturbances) or as tracking controllers (e.g. to follow reference changes). If both characteristics are important then a compromise design has to be found. Here a special ‘connection’ of the classical PI(D) controller is proposed, which allows a greater degree of independence in the design and practical tuning of the regulating and tracking features.

ISSN:0020-7179    

DOI:10.1080/00207178708933711

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Sufficient conditions for finite pulse stability of interconnected systems with combined pulse frequency and pulse width modulation are developed in this paper using a direct method. The stability criteria established provide upper bounds on the number of pulses emitted by each modulator. The results are also applicable to those systems which contain a finite number of pulse frequency modulators and a finite number of combined pulse frequency and pulse width modulators.

ISSN:0020-7179    

DOI:10.1080/00207178708933712

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A new approach is presented for the design of constant feedforward controllers which minimize the effect of an external disturbance on the output variables at specified frequencies. The multi-variable design problem is formulated in the frequency domain and treated as a classical minimization problem. It is shown here that a unique constant feedforward controller to minimize the effect of disturbances almost always exists. A numerical example is included to illustrate the application of the method.

ISSN:0020-7179    

DOI:10.1080/00207178708933713

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper is an exact parallel to the solution of the stochastic feedback control problem in discrete time given in Kucera's book (1979). The difference is that here it is shown that usually it is only necessary to solve one, rather than two, diophantine equations. The resulting reduction in dimension will be particularly important in large-scale systems.

ISSN:0020-7179    

DOI:10.1080/00207178708933714

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The importance of the concept of persistent excitation (PE) in adaptive identification and control has been recognized for some time. Recently it has become evident that it also plays a central role in many questions related to the robustness of adaptive systems. There is every reason to believe that arguments involving this concept will continue to feature prominently in the analysis of most of the important problems of adaptive control. Hence there is a real need for a deeper understanding of the concept. The paper is written with three objectives. The first, which is tutorial in nature, is to provide a general framework for the discussion of persistent excitation and to collect results in the area, which are scattered throughout the adaptive literature. The second objective is to present some new results related to the uniform asymptotic stability (u.a.s.) and robustness of adaptive systems and the relation of PE to the stability properties of a class of non-linear systems. The final objective is to discuss the implications of PE in future problems, including adaptive control using a reduced-order model.

ISSN:0020-7179    

DOI:10.1080/00207178708933715

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor