Patent ID: 8723472

Claim:
A servo control device that is applied to a numerical control equipment provided with a screw-feeding section that converts rotational movement of a motor to linear movement, a driven section that is linearly moved by the screw-feeding section, and a support member by which the screw-feeding section and the driven section are supported; and that is configured to control the motor so as to match a position of the driven section to an instructed position, comprising: a machine-deflection compensating section, to which the instructed position is input as input information, and which is configured to compensate for positioning-control errors caused by vibrations of the support member, and to output a compensated instructed position; and a velocity feedforward section, to which the compensated instructed position is input; wherein the velocity feedforward section includes a support-member-reaction-force compensating section that is configured to compensate for vibrations of the driven section due to vibrational reaction force of the support member, and wherein a differential value of the compensated instructed position, as input information, is input to a transfer function, which is provided in the support-member-reaction-force compensating section and includes coefficients based on an inertia term for the support member, an inertia term for the driven section, a stiffness term for the support member, and a stiffness term for the driven section.