STATIC CHARACTERISTICS ANALYSIS OF INDIRECT CONTROL FLOW VALVE

Abstract

A model of the indirect control flow divider for the steady state operation which maintains a twin-engined hydromechanical system in the synchronous common mode is considered. The divider is presented as an astatic regulator consisting of the sensor, amplifier, and regulating elements. However, its main static characteristics are the dependences of the timing failure on the regulating element spool speed, and those of the regulating element spool speed on the input control. The investigation of the static characteristics conducted according to a special program developed in the Mathcad package allows determining the presence of the hysteresis nonlinearity. The presence of the ambiguity zone is a troublesome factor indicating the self-oscillations onset probability in the closed loop system having a controller with such a property. In this case, the system would require the design constraints to ensure the characteristic of proportionality with saturation. Various design and operating parameters for the flow divider of the indirect control and the hydromechanical system are analyzed. This allows evaluating its effect, range of variation, and obtaining the basic approaches to designing synchronous in-phase systems. Two astatic regulator models with and without leakage at the amplifier element, as well as various types of the amplifier orifice overlapping are considered. This analysis has demonstrated the sufficient accuracy of the models, and the agreement of the results under the boundary conditions.