Response of nonlinear characteristics to several inputs and the use of the modified nonlinearity concept in control systems

Methods for obtaining the response of a nonlinearity to several uncorrelated inputs are considered. The majority of these methods involve approximate solutions that can lead to rapid calculation of the various output terms, and in most cases a sufficiently high degree of accuracy can be obtained without excessive labour. The concept of the modified nonlinearity is introduced and its value calculated in some cases. It is shown how, under certain conditions, its use may be extended to deal with a double-valued nonlinearity. An example is given to illustrate how the concept may be applied to the design of a simple adaptive system.