Self-adjusting Systems Research Articles

Qualitative Study of Dynamics of Neuron Nets

Living nature offers many remarkable examples of adaptive behavior, of self-adjustment of organisms. Self-adjusting systems comprise not only individual organisms such as man, whose adaptive abilities are obvious, but also aggregates of such organisms, for example, species, whose evolution over millions of years represents a continuous process of adaptation to external conditions. In terms of many, if not all, useful criteria, “living” adaptive systems are not only superior to existing technical devices used for control and adaptation, but also to any foreseen devices that might be used to implement already developed algorithms. Therefore it is interesting and important, for advancement of biology as well as for engineering and control theory, to discover the principles of organization of adaptive responses of living organisms and study the actual physiological mechanisms based on these principles.

Methods of Synthesis of Structures Equivalent to Self-Adjusting Systems for Plants with Variable Parameters

Methods are devised to construct structures of systemes without searching elements equivalent to self-adjusting systems for plants with time-variable parameters. Design of such structures reduces to finding the conditions for stability in the large of an equation with time variable free term. Sufficient conditions for stability in the large are obtained in the analytical form.

On a class of control systems invariant to parameter changes

Publisher Summary This chapter discusses the class of control systems invariant to parameter changes. Parameter variations may result in deterioration of system performance, and sometimes also in the loss of stability. Simple control systems cannot in general ensure satisfactory performance in the presence of large parameter variations. To preserve the specified performance it is, therefore, necessary to readjust the controller and this is being done automatically in self-adjusting systems. There are many different definitions of self-adjusting systems. The term self-adjusting is used to describe those systems that preserve their dynamic properties in the presence of system parameter variations. Self-adjusting systems are universal and permit a single control structure to be applied to a broad class of plants with variable parameters ensuring the required transient performance, and system stability under continuous variation of parameters within a fairly large range. Self-adjusting systems do not require the extensive experimental investigations and calibrations that are necessary when an ordinary controller is connected to a new plant.

Design of self-adjusting control systems by use of a functional derivative technique

Publisher Summary This chapter describes the design of self-adjusting control systems by use of a functional derivative technique. Such systems are usually aimed at compensating drift in the controlled plant, often described by nonlinear differential equations. The compensation will be performed by a mechanism that receives measurements from the observed plant variables and also contains information about the control objective. In addition, owing to the drift, it is normally necessary to incorporate, in some way or another, an identification of the plant. As a rule, the mechanism needed for handling all this information and performing the optimization operations tends to become complex and awkward and impractical. The particular technique explored in the chapter leads to self-adjusting mechanisms whose main part can be implemented by solving differential equations only. There will be no need to store functions, or to invert matrices, and the implementation can be performed by analog means and with digital computers.

Sensitivity and dynamic accuracy of control systems

Publisher Summary This chapter describes sensitivity and dynamic accuracy of control systems. The problem of sensitivity of dynamic systems, and particularly of control systems, with respect to parameter changes occupies a very important place in modern engineering. The interest in this problem is twofold. On the one hand, in the physical realization of automatic control system, uncontrolled parameter changes are constantly encountered that are the consequence of component aging, of environmental influences, of mutual coupling with other systems, and of the specific technological processes used in constructing the system. On the other hand, there is an ever increasing tendency to build automatic control systems with variable structure, where the possibility of changing parameters is intentionally introduced to achieve adaptation properties as, for example, in optimal and self-adjusting systems. The chapter presents a precise definition of the notion of system sensitivity and the method of transformed systems.

Synthesis of systems with fixed structures of equivalent self-adjusting systems

The paper describes the methods of designing automatic control systems with constant structures and constant parameters, the properties of which are equivalent to one of the adaptive systems. These systems are based on the structures which admit an unlimited increase of gains without disturbing the stability. It is shown that the presence of the disturbance at the input of the compensating network (when the disturbance can be measured) or the introduction of the model of the plant to the system provides, for the chosen structure of the whole system, the removal of the influence of external disturbances. It is concluded that the sensitivity, according to Bode, for the mentioned structures does not depend on the parameters of the plant, nor does its value tend to zero under the corresponding increase of the gain.

A Review of Self-adjusting Systems in Automatic Control†

ABSTRACT Problems arising in the application of techniques of automatic control to complex non-linear systems subject to random disturbances may be solved by automatic optimization. A variety of such schemes have been proposed. These are discussed with reference to a performance criterion which is to be optimized; they may be classified as employing either open-loop or closed-loop methods of optimization. A terminology is suggested for the description of such systems.

The use of self-adjusting automatic control systems

The use of self-adjusting automatic control systems