Adaptive Servomechanisms

A discussion is given on some of the current ideas behind the control engineer´s approach to the problem of developing servomechanisms which exhibit some degree of adaptive behavior. Several categories of adaptive systems are discussed and an attempt is made to associate the operating principle of the systems in each category with the behavior of the human being when he acts as a controlling device. A particular system developed for application in the field of automatic flight control is discussed from a functional point of view. The controller, using an analog model which operates on the input information, determines a ``standard of performance´´ for the controlled element which closely approximates the performance desired by an experienced operator. The remainder of the controller, using a very simple passive network as a switching function computer to determine the state of a bistable device, forces the controlled element to operate in such a manner as to minimize continuously the error between the desired performance and the actual performance. The controller exhibits adaptive behavior in the sense that it operates in such a manner as to keep the actual performance of the system practically invariant, although the parameters of the controlled element change over a relatively wide range of values.