摘要:

The stability and bifurcation behaviour of a non-linear autonomous system in the vicinity of a compound critical point where the jacobian of the system exhibits three distinct pairs of pure imaginary eigenvalues is discussed. The system under consideration is assumed to have three independent parameters. The solutions for the incipient Hopf bifurcations as well as the sequences of bifurcations leading to two and high dimensional tori are explored. The analysis is carried out via a recently developed approach—the ‘unification technique’ and ‘multiple-scale intrinsic harmonic balancing’. The approach enables one to obtain systematically a sel of simplified rate equations which govern the local dynamics of the system. This more comprehensive perturbation procedure leads to explicit asymptotic results concerning the bifurcation solutions and the associated stability conditions. An example drawn from electrical networks is analysed to demonstrate the applicability of the theory and analytic results.

ISSN:0020-7721    

DOI:10.1080/00207729008910430

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The design problem of servo systems for distributed parameter systems is investigated. The output regulator of integral type is designed in order to guarantee internal stability and output regulation. The design procedure based on a dynamic stabilizing compensator is discussed. The output regulation of a wide class of distributed parameter systems is proved under the condition that a closed-loop system is stabilized by a dynamic compensator of general type. Then a closed-loop system can be stabilized by a finite dimensional dynamic compensator under some additional conditions. The reducabitity of the design procedure to a purely finite dimensional one is discussed.

ISSN:0020-7721    

DOI:10.1080/00207729008910431

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Concepts of structural and industrial efficiency are developed for comparing productive efficiencies of two or more clusters and their mathematical characterizations worked out in the framework of data envelopment analysis. Some criteria of comparison of two or more similar clusters or aggregates of firms are developed and their relations with stochastic dominance and statistical distance between distributions explored.

ISSN:0020-7721    

DOI:10.1080/00207729008910432

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Measures of overshoot, speed of response and robustness are derived based on the state transition matrix of the closed-loop system. A measure of overshoot is defined as the maximum value of the weighted norm of the state transition matrix. An exponentially decaying envelope is defined which confines the norm of the state transition matrix. The ratio of the amplitude and decrement factor defining the envelope is shown to be a measure of robustness. Comparison with other measures is given. The importance of the proposed measures is illustrated using numerical examples.

ISSN:0020-7721    

DOI:10.1080/00207729008910433

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The busy period of a permit buffer in a window-controlled virtual route is analysed using the method of sub-busy-periods partition. A non-linear recurrence equation for busy period p.d.f. (transformable into a continued fraction) is derived. Mean busy-period length is calculated; some similarities to the open M/G/l system are indicated. The limiting case of the busy-period equation, as both window size and virtual route length approach infinity, is investigated. It is shown that in the limit the permit buffer is equivalent to the M/M/l system from the busy and idle period points of view. The accuracy of the M/M/l model is inspected via simulation and numerical computations. The M/M/l model renders power optimization in a window-controlled virtual route easy, It has been shown that transmission power is optimized at a window size equal to the virtual route length, independently of an offered load. A simple operational rule for permit power optimization is also provided.

ISSN:0020-7721    

DOI:10.1080/00207729008910434

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

An algorithm that enhances the stability and traction of a road vehicle (which may be steering) during ‘acceleration’ (meaning either braking or accelerating) is presented. This algorithm has two domains: partial-effort acceleration and maximum-effort acceleration. During partial-effort acceleration, stability enhancement requires only proper distribution of longitudinal traction forces. During maximum-effort acceleration, stability enhancement requires distribution and reduction of longitudinal traction forces. The algorithm attempts to provide the desired levels of acceleration while it simultaneously constrains trajectory disturbance of the vehicle. The algorithm uses total information about the road surface characteristics, the driver's actions, and the vehicle's design and dynamic states. It fully accommodates non-linear vehicle dynamics and tyre force characteristics. The algorithm has the form of a linear program and its operation is traced in a series of graphs where the geometry of linear programming is used as a setting.

ISSN:0020-7721    

DOI:10.1080/00207729008910435

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

By the use of a simple predictor for dead time compensation, we show that an explicit pole-assignment algorithm can become or practical importance for processes with relatively large time delays. With the omission of the delay term in the closed-loop characteristic polynomial, solution of the pole-assignment control algorithm becomes computationally more efficient. The closed-loop system with an adaptive pole-assignment algorithm and a dead time compensation scheme is shown to be globally stable. The stability analysis is applicable to both minimum-phase and non-minimum-phase systems. For a particular class of processes, it is shown that the pole-assignment algorithm can take the form of a velocity-type, three-term, adaptive PID controller.

ISSN:0020-7721    

DOI:10.1080/00207729008910436

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

State smoothing and filtering are treated for non-linear dynamic systems in the absence of observations in a considered observation interval. Models are taken to be non-linear functions of the states, disturbance noises, and observation noises, whereas the state estimation of these models cannot, in general, be performed by classical estimation schemes, such as the extended Kalman filter. State estimation is performed in blocks by estimating missing observations with interpolating functions. The resulting estimation scheme requires a constant memory for its implementation.

ISSN:0020-7721    

DOI:10.1080/00207729008910437

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The following mechanism of multiple failures in a system is considered. Suppose that the failure of a component eicauses with probability pij ≤ 0 an instantaneous failure of a component eiwhich can, in turn, cause another instantaneous failure of ekwith probability PJk0 and so on (i,j, k = 1, 2,..., n). We apply this mechanism to the Marshall and Olkin formula for the joint probability distribution of system component lifetimes when multiple failures in the system occur. The formulae given replace the Marshall and Olkin constant set failure rates by variable ones. Other comparisons with Marshall and Olkin models are made.

ISSN:0020-7721    

DOI:10.1080/00207729008910438

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor