Method and apparatus for improved flow control

摘要

A method and apparatus for improved flow control. A flow metering valve has an actuator formed of magnetic material which moves on response to an applied magnetic field to control fluid flow through the valve. A servo-control circuit receives a position command signal representative of a desired position of the actuator and produces an output command to produce a magnetic field in response thereto. The magnetic permeability of the actuator modifies the applied field and a magnetic field sensor measure the modified magnetic field to determine the position of the actuator. An actual position signal representative of the position of the actuator is negatively fed back to the servo-control circuit which produces an updated version of the output command.