摘要:

A new state estimation scheme is presented for multidimensional dynamic systems. The state vector is estimated, component-by-component, by the parallel use of the stack sequential decoding algorithms of information theory. A faster state estimation is accomplished with this scheme for longer time intervals with available memory. Simulation results, some of which are presented, have shown that the scheme produces better estimates than the Kalman estimates for some non-linear models with white gaussian observation and disturbance noise, while it produces estimates comparable with the Kalman estimates for linear models with white gaussian noise.

ISSN:0020-7179    

DOI:10.1080/00207178808906157

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This technical note describes a method for computing the exact numerical value of the variance of a two-dimensional (2–D) ARMA process. Such calculations are useful in connection with current work on 2–D smoothers and predictors. Comparison is made of various methods of variance calculation using both 1–D and 2–D models.

ISSN:0020-7179    

DOI:10.1080/00207178808906158

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new solution for the multivariable minimax optimal robust design problem is presented. The relationship between LQG andH∞design methods is considered and theH∞solution is obtained from the solution of a related LQG problem. The approach provides insights into the relationship between theH∞and LQG design philosophies. The H∞solution involves the same type of steps which are involved in the polynomial–based solutions of the LQG problem, namely spectral factorization and the solution of linear (diophantine) equations. A simplified design procedure is described which requires only the solution of a standard eigenvalue/eigenvector problem.

ISSN:0020-7179    

DOI:10.1080/00207178808906159

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

We consider the problem of controlling the heat flow at a boundary in the framework of the linear diffusion equation in one spatial dimension. By the use of equations based on the theory of differential forms, it has been possible to derive linear relations between the moments of the boundary functions and those of the control function; these relations play the role of state equations in the optimal control problem considered, which is that of approaching in an optimal manner a given heat flow pattern at a boundary. We then introduce an approximation scheme that can be used for the numerical estimation of the optimal control. The approach can be extended to the control of non-linear diffusion equations with polynomial non-linearities.

ISSN:0020-7179    

DOI:10.1080/00207178808906160

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Dynamic interaction with the environment is fundamental to the process of manipulation. This paper describes an approach to the design of ‘interaction controllers’ and contrasts this with an approach to servo design. The need for ‘coupled stability’ and ‘interactive behaviour’ specifications is motivated. A necessary and sufficient condition to ensure the stability of a linear manipulator coupled at a single interaction port to a linear, passive environment is found. It is shown that this condition may be extended to a broad class of active environments, and a simple test for coupled stability, based on the root locus, is presented. Two interaction controller designs for a linear manipulator are presented. Interactive behaviour is analysed in the frequency domain by comparison with the behaviour of a target model. A simple controller shows strong stability properties, but poor behaviour; a more sophisticated design shows that it is possible to achieve desirable behaviour while retaining stability guarantees.

ISSN:0020-7179    

DOI:10.1080/00207178808906161

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Classes of reachable pairs over certain principal ideal domains are described, for which feedback cyclization is possible. This leads to a necessary condition for feedback cyclization in terms of solving some algebraic equations.

ISSN:0020-7179    

DOI:10.1080/00207178808906162

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This paper develops an efficient multistage parametric approach for eigenstructure assignment in linear multivariable systems by output-feedback control. The sets of closed-loop eigenvalues and associated eigenvectors are suitably divided into subsets and the entire eigenstructure is constructed by parts in two (or more) consecutive stages. This allows the subsets of right and left eigenvectors to be assigned in separate stages and thus the computational algorithm is relaxed from the orthogonality conditions. The number of effective free parameters beyond eigenvalue assignment is determined, and the notion of redistributing these parameters among the assignable right and left eigenvectors is introduced. Numerical examples are included to demonstrate the design procedure.

ISSN:0020-7179    

DOI:10.1080/00207178808906163

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

When identifying rational polynomial transfer functions from input-output data, estimates of the coefficients and their covariances can be obtained. However, the estimated value of any given coefficient depends considerably on the chosen model order, leading to segmented confidence regions when the model order is not known. Fortunately the frequency responses of the transfer function models are little affected by using too high a model order. These are more likely to have a consistent estimate with a single surrounding confidence region, In this paper, the confidence limits established for the frequency response of single-input-single-output systems by Edmunds are extended to multivariable systems. A statistical lest of the method is then carried out using an illustrative example.

ISSN:0020-7179    

DOI:10.1080/00207178808906164

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The decentralized determinantal assignment problem (DDAP) is defined as the unifying description for the study of pole and zero assignment problems under decentralized output, state feedback (DOF, DSF) and decentralized ‘squaring down’ (DSD), respectively. DDAP is reduced to a linear problem of zero assignment of polynomial combinants and a multilinear problem of restricted decomposability of multivectors. The decentralization characteristic (DC) and the decentralized polynomial Grassmann representative )D — ℝ[s] — GR) of DDAP are defined. The fixed zero polynomial of DDAP is then determined as the zero polynomial of D— ℝ[s]—GR. The canonical D—ℝ[s]—GR, (CD—R[s]—GR) and the decentralized Plücker matrix (DPM) of DDAP are introduced and necessary conditions for arbitrary assignment of the non-fixed zeros are given in terms of the DPM. The family of strongly zero non-assignable (SNA( systems is defined, and for such systems the notion of the fixed zero is extended to that of the ‘almost fixed zero’ (AFZ). An AFZ is defined as the centre of a disc that contains at least one zero of the combinant under any decentralized compensator and as such the AFZs define ‘trapping’ discs for the exact zeros. The general properties and computational aspects of the radii of the ‘trapping’ discs are discussed and a new necessary condition for stabilizability is given in terms of the AFZs. Finally, the results are specialized to the case of pole-zero assignment under DOF (DSF), DSD, respectively. Criteria for fixed and almost fixed modes under DOF (DSF), and fixed and almost fixed zeros under DSD are given, as well as new necessary conditions for decentralized pole-zero assignment.

ISSN:0020-7179    

DOI:10.1080/00207178808906165

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The proposed identification algorithm uses output values y(KJT), sampled after J intervals of duration T, and input values u(kT), where k = 0, 1, 2,.... It is proven that the estimated output ŷ(kT) converges asymptotically to the measured output al each sampling instant. The significance of the algorithm is that it provides a basis for control based on ŷ(kT) to be performed at intervals of T rather than JT and thereby improves control performance. Simulated results show open-loop convergence of ŷ(kT) to y(kT) for J = 10.

ISSN:0020-7179    

DOI:10.1080/00207178808906166

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor