Self-zeroing self-adaptive control system

A fully automatic self-adaptive control system is described. The basic uncompensated system consists of a second-order controller and a second-order process which are connected in series and enclosed by an overall feedback loop. The characteristics of the controller are constant; the bandwidth of the process is a variable. A configuration of this type is often encountered in flight control. The self-adaptive feature is achieved by means of a subsidiary loop. This loop detects changes in the process bandwidth and compensates for these changes by the continuous adjustment of a compensating element which is common to the basic system and the subsidiary loop. This compensating action is based on the difference that exists between the actual compensation that is inserted into the system and the amount that is required. An h.f. sinusoidal signal is used to probe the process. The performance of the self-adaptive system is shown to be invariant for both transient and sinusoidal inputs.