Servo controller, control method, and computer-readable recording medium for machine tool used for oscillating cutting

A method of controlling a machine tool comprising multiple control axes and used for machining by cutting of a work as a machining target by means of coordinated motion of the control axes, the method comprising:

• a position command acquiring step of acquiring a position command directed to a servo motor for driving a cutting tool or a position command directed to a servo motor for driving the work;
• a position acquiring step of acquiring the position of the cutting tool or that of the work as a position feedback value;
• a positional deviation calculating step of calculating positional deviation using the acquired position command and the acquired position feedback value;
• a spindle axis angle acquiring step of acquiring a spindle axis angle of the rotated work or that of the rotated cutting tool;
• an oscillation command calculating step of calculating an oscillation command for causing the servo motor to perform an oscillating motion using the acquired position command and the acquired spindle axis angle, or using the acquired position feedback value and the acquired spindle axis angle;
• an oscillation offset calculating step of calculating an offset using the calculated positional deviation, the calculated oscillation command, and the spindle axis angle, the offset being added to the oscillation command to generate an adjusted oscillation command for causing the servo motor to perform the oscillating motion;
• and
• a driving step of determining a drive signal to be used for driving the servo motor including causing the servo motor to perform the oscillating motion based on the positional deviation and the adjusted oscillation command, and outputting the drive signal.

A non-transitory computer-readable recording medium storing a computer program that causes a computer to operate as a controller that controls a machine tool comprising multiple control axes and used for machining by cutting of a work as a machining target by means of coordinated motion of the control axes, the computer-readable recording medium storing a computer program causing the computer to execute:

• a position command acquiring procedure of acquiring a position command directed to a servo motor for driving a cutting tool or a position command directed to a servo motor for driving the work;
• a position acquiring procedure of acquiring the position of the cutting tool or that of the work as a position feedback value;
• a positional deviation calculating procedure of calculating positional deviation using the acquired position command and the acquired position feedback value;
• a spindle axis angle acquiring procedure of acquiring a spindle axis angle of the rotated work or that of the rotated cutting tool;
• an oscillation command calculating procedure of calculating an oscillation command for causing the servo motor to perform an oscillating motion using the acquired position command and the acquired spindle axis angle, or using the acquired position feedback value and the acquired spindle axis angle;
• an oscillation offset calculating procedure of calculating an offset using the calculated positional deviation, the calculated oscillation command, and the spindle axis angle, the offset being added to the oscillation command to generate an adjusted oscillation command for causing the servo motor to perform the oscillating motion;
• and
• a driving procedure of determining a drive signal to be used for driving the servo motor including causing the servo motor to perform the oscillating motion based on the positional deviation and the adjusted oscillation command, and outputting the drive signal.