Servo control device and servo control method

A servo control method of a servo control device which is applied to a numerical control apparatus including a screw feed unit that is provided for each of a plurality of axes and converts rotational movement of a motor to linear movement, a driven unit that is moved linearly by the screw feed unit, and a support body that supports the screw feed unit and the driven unit and which includes, in order to control the motor so as to match a position of the driven unit to a position command, feedback means for performing feedback control for matching the position of the driven unit to the position command for each of the axes and feed forward means for performing feed forward control for compensating a delay in position control for the driven unit due to the feedback control for each of the axes, the method comprising:

• a first step of performing feedback control by changing the feedback gain for each of the axes to the same value set in advance when the feed forward control is OFF;
• and
• a second step of performing feed forward control by changing a feedback gain based on the feedback control to a predetermined value corresponding to each of the axes when the feed forward control of the feed forward means is ON.