DELAY DIFFERENTIAL EQUATIONS MODELS FOR MECHANO AND ELECTROHYDRAULIC SERVOMECHANISMS

The problem of modeling hydraulic servomechanisms as systems with time delay is less researched, although the input-output time delay is herein objective and, in fact, real in every system which involves load dynamics. The objective of this paper is to propose a few types of delay differential equations which characterize the dynamics of the hydraulic servomechanisms from the primary flight controls of an airplane. The hydraulic servomechanism (mechanical or electrical) is a feedback control system. Therefore three possible locations for the time delay are herein taken into account: on state variables, on measurement variables, and on control variables.