A describing function for multiple nonlinearities present in electrohydraulic control valves

A SPECIFIC and a general objective are jointly pursued by this paper. The specific aim is the development of a describing function1 to represent the principal nonlinearities occurring in single-stage 4-port electrohydraulic control valves of the type sketched in Fig. 1. For maximum usefulness of the describing function towards this specific objective, it is expressed in a generalized and dimensionless form. Consequently it is applicable to the analysis or design of electrohydraulic control valves for any individual application. Precalculated curves reduce to very reasonable amounts the labor of computing the describing function for a given valve.