STAGE CONTROLLER

PURPOSE:To control a transferring table having high precision and high resolving power at a stage controller by a method wherein an automatic changeover function of dither and an automatic setting function of transferring speed signal are provided. CONSTITUTION:A pressure oil cylinder 3 controlled by an electro-hydraulic flow control valve 4 makes a transferring table 2 to perform rectilinear progress motion. The position of the table 2 is measured by a laser measuring machine 5, an actually transferred distance and an aimed transferring distance are compared by a comparator 7, and output thereof is converted into an analog voltage by a D/A converter 9. A constant-voltage generating circuit 12 decides a reference transferring speed of the transferring table 1, while a multiplying D/A converter 17 multiplies output thereof into a digital signal of a computer 8 for control to convert an aimed transferring speed signal into an analog voltage. The outputted analog signals thereof are selected by an analog switch 10 to be inputted into a servo-amplifier 13. An output signal of a dither oscillator 14 to apply an oscillation to a spool of the flow control valve 4 is multiplied into the signal sent from the computer 8 by a multiplying D/A converter 18 to be inputted into the servo-amplifier 13.