An Identification Procedure For Discrete Multivariable Systems

The report describes a procedure for adjusting the parameters of a model for the identification of linear and nonlinear discrete multivariable systems when all the state variables are accessible and no observation noise is present. The scheme is shown to be stable when using Lyapunov's direct method.

In the paper, the direct method of Lyapunov is employed to outline a procedure for the identification of a discrete multivariable system from the measurements on the inputs and the state variables of the system. It is assumed that all the state variables of the plant are accessible and that there is no measurement noise. The procedure results in the convergence of every parameter of a model to the corresponding one of the system as the number of stages k nears infinity. The overall process is also shown to be asymptotically stable. (Author).

In view of the importance of system identification, the International Federation of Automatic Control (IFAC) and the International Federation of Operational Research Societies (IFORS) hold symposia on this topic every three years. Interest in continuous time approaches to system identification has been growing in recent years. This is evident from the fact that the of invited sessions on continuous time systems has increased from one in the 8th number Symposium that was held in Beijing in 1988 to three in the 9th Symposium in Budapest in 1991. It was during the 8th Symposium in August 1988 that the idea of bringing together important results on the topic of Identification of continuous time systems was conceived. Several distinguished colleagues, who were with us in Beijing at that time, encouraged us by promising on the spot to contribute to a comprehensive volume of collective work. Subsequently, we contacted colleagues all over the world, known for their work in this area, with a formal request to contribute to the proposed volume. The response was prompt and overwhelmingly encouraging. We sincerely thank all the authors for their valuable contributions covering various aspects of identification of continuous time systems.

In this book, we study theoretical and practical aspects of computing methods for mathematical modelling of nonlinear systems. A number of computing techniques are considered, such as methods of operator approximation with any given accuracy; operator interpolation techniques including a non-Lagrange interpolation; methods of system representation subject to constraints associated with concepts of causality, memory and stationarity; methods of system representation with an accuracy that is the best within a given class of models; methods of covariance matrix estimation;methods for low-rank matrix approximations; hybrid methods based on a combination of iterative procedures and best operator approximation; andmethods for information compression and filtering under condition that a filter model should satisfy restrictions associated with causality and different types of memory.As a result, the book represents a blend of new methods in general computational analysis,and specific, but also generic, techniques for study of systems theory ant its particularbranches, such as optimal filtering and information compression. - Best operator approximation,- Non-Lagrange interpolation,- Generic Karhunen-Loeve transform- Generalised low-rank matrix approximation- Optimal data compression- Optimal nonlinear filtering

Computer Aided Design of Control Systems focuses on the use of computers to analyze and design the control of various processes, as well as the development of program packages with different algorithms for digital computers. The selection first takes a look at the computer aided design of minimal order controllers, including design of interacting and noninteracting dynamic controllers of minimal order and basic algorithm. The book then discusses an accelerated Newton process to solve Riccati equation through matrix sign function; suboptimal direct digital control of a trickle-bed absorption column; and structural design of large systems employing a geometric approach. The text underscores the computer as an aid for the implementation of advanced control algorithms on physical processes and analysis of direct control algorithms and their parallel realization. Topics include hardware influences on the control, process influence, and interactive structure design of direct control systems. The book also takes a look at the optimal control of randomly sampled linear stochastic systems; computer aided design of suboptimal test signals for system identification; and computer aided design of multi-level systems with prescribed structure and control constraints. The selection is a dependable source of data for readers interested in the uses of computers.

Recent results in the development and application of analysis and design techniques for the control of multivariable systems are discussed in this volume.

This book joins the multitude of Control Systems books now available, but is neither a textbook nor a monograph. Rather it may be described as a resource book or survey of the elements/essentials of feedback control systems. The material included is a result of my development, over a period of several years, of summaries written to supplement a number of standard textbooks for undergraduate and early post-graduate courses. Those notes, plus more work than I care right now to contemplate, are intended to be helpful both to students and to professional engineers. Too often, standard textbooks seem to overlook some of the engineering realities of (roughly) how much things cost or how big of hardware for computer programs for simple algorithms are, sensing and actuation, of special systems such as PLCs and PID controllers, of the engineering of real systems from coverage of SISO theories, and of the special characteristics of computers, their programming, and their potential interactions into systems. In particular, students with specializations other than control systems are not being exposed to the breadth of the considerations needed in control systems engineering, perhaps because it is assumed that they are always to be part of a multicourse sequence taken by specialists. The lectures given to introduce at least some of these aspects were more effective when supported by written material: hence, the need for my notes which preceded this book.