초록 ▼

A novel digital servo valve system for use in displacing an actuator is capable of operating either in closed or open loop mode. The system includes a controller that compares computed values of actuator parameters with preselected parameter values and iteratively determines therefrom command signal

A novel digital servo valve system for use in displacing an actuator is capable of operating either in closed or open loop mode. The system includes a controller that compares computed values of actuator parameters with preselected parameter values and iteratively determines therefrom command signals for the servo valve. The servo valve is characterized by a ball screw mechanism that eliminates mechanical backlash and a torsion bar which increases radial and angular compliance. A servo valve provided according to the present invention also displays reduced flow forces using a simple, inexpensive valve body in combination with a uniquely configured displaceable spool.

대표청구항 ▼

A digital servo valve system for controlling a displaceable actuator, comprising: valve body having an interior longitudinal cavity with a plurality of channels spaced therealong, each of said channels respectively communicating with a fluid pressure source, a fluid pressure return and the actuator;

A digital servo valve system for controlling a displaceable actuator, comprising: valve body having an interior longitudinal cavity with a plurality of channels spaced therealong, each of said channels respectively communicating with a fluid pressure source, a fluid pressure return and the actuator; a valve spool displaceable within said cavity along a longitudinal axis, said valve spool having a plurality of substantially cylindrical lands alternately spaced with a plurality of recessed regions, said spool cooperatively configured with said valve body to regulate fluid flow through said channels in dependence on said spool axial displacement; a rotary to linear translation means affixed to said valve body and said spool for translating received rotational displacement to linear displacement of said spool; feedback means for providing signals indicative of actuator displacement; motor means connected with said rotary to linear translation means for providing discrete rotary displacement in response to position command signals; a controller receiving said feedback signals and actuator control signals, said controller computing present actuator parameter values and comparing said computer values with nominal actuator parameter values and iteratively determining from said received and computed signals said position command signals; said controller in computing said position command signals utilizes said feedback signals to compute actuator present position values and compares these values with a commanded final position to determine if the actuator is within a selected distance from the commanded final position; and wherein when said controller determines that the actuator is within said selected distance, it alters said position command signals to cause said motor means to decelerate said valve spool along said selected distance such that the valve spool is positioned at the commanded final position without overshoot.