Automatic Control by System Variable Adaptation†

Abstract

ABSTRACT The performance of an automatic control system can be improved by the addition of subsidiary feed-back loops whose characteristics are controlled by signal polarities. This paper describes an analogue computer study that was made of the properties of a system of this type. The system consists of a second-order linear feed-forward section and a feed-back section which contains two subsidiary loops. Signal polarities are used to control the amounts of rate and proportional feed-back that are transmitted by these subsidiary loops. The sensitivity of the system to changes in the damping and natural frequency of the linear feed-forward section was evaluated using sinusoidal and transient inputs. The results show that the addition of these subsidiary loops makes the system very insensitive to changes in the damping. The sensitivity of the system to changes in the natural frequency is not reduced.