On Soft Sensing for Instantaneous Flow in Hydraulic System

摘要

The measurement of high frequency dynamical flow in dynamical test of Electro-hydraulic proportional valve and Electro-hydraulic servo valve is very difficult. In present, the soft sensing theory is utilized for measuring the high frequency dynamical flow. Basing on the Laminar flow theory of fluid flow, the mathematic model of instantaneous flow in dynamic flow course is given. During the measurement, the differential pressure between two cross-cut sections along the pipe and the temperature of the fluid are measured online at first. Then the instantaneous flow at any time can be calculated and output by computer through special program, which can easily be implemented on a personal computer and takes less memory and computational time. In this way, the developed soft sensing flow meter is a marked advantage over traditional pressure-type flow meter.