Electrohydraulic control system

摘要

An electrohydraulic control system with mechanical position sensing feedback is presented. A movable flight control canard is rotatably operated for providing flight control of the missile. A hydraulically powered actuator is mounted to the airframe with the canard being secured to the actuator shaft for controlled rotation of the canard. Hydraulic fluid under pressure enters the actuator at its base controlled via a rotary valve. A stepper motor is mounted to the canard and is geared to drive the rotary valve as determined by digital control signals generated by the missile guidance computer. When the stepper motor receives a train of pulses, the stepper motor rotor rotatingly moves the rotary valve from the null or closed position to an open position admitting hydraulic fluid into the rotary actuator causing the canard to turn. The stepper motor rotates along with the canard and provides position feedback for closing the rotary valve when the canard has reached the equilibrium position determined by the control signal.