Servo control system operable on digital basis.

摘要

A digital servo control system responsive to a command signal indicative of a commanded position of a movable element and a phase-modulated position signal having a phase responsive to a predetermined incremental angle of rotation of a motor rotatable with a variable angular velocity to vary the present position of the element, comprises incremental position pulse producing means responsive to the phase-modulated position signal for producing incremental position pulses representative of a variation in the current position, and control signal producing means responsive to the command signal and the position pulses for calculating a displacement from the current position to , the commanded position and for producing a control signal digitally representative of a reference angular velocity selected for the motor in consideration of the displacement until an instant at which the displacement is reduced in absolute value to a predetermined value, a first positional error being determined by the displacement during a prescribed interval of time following the above-mentioned instant, and a second positional error having a value increasing in absolute value with relation to the displacement when a predetermined interval of time elapses after the abovementioned instant.