Motor control apparatus for correcting interpolation error of position detector

A motor control apparatus, comprising:

• a position detector for detecting the position of a rotor of a motor;
• a speed detection unit for calculating a speed detection value based on a position detection value detected by the position detector;
• a speed command generation unit for generating, a speed command which commands a rotation speed of the rotor of the motor;
• a correction amount calculation unit for calculating a correction amount based on the position detection value detected by the position detector;
• a correction processing unit directly coupled to the correction amount calculation unit and the speed detection unit for receiving the correction amount and the speed detection value, respectively, and the correction processing unit correcting the speed detection value by using the correction amount;
• and a torque command generation unit for generating a torque command which commands a rotational torque of the motor based on the speed command and the speed detection value corrected by the correction processing unit,
• wherein the correction amount calculation unit calculates the correction amount by superposing a plurality of sinusoidal waves, and increasing a number of said plurality of superposed sinusoidal waves until the difference between a torque command error and the correction amount is within a predetermined range, and wherein each of the sinusoidal frequency components has a value which is a natural number times a basic frequency determined by a rotation frequency of the motor and a physical scale number of the position detector, and
• wherein the correction amount=Σn=1mgn sin(nθ+ψn), where each of m and n is a natural number (1≤n≤m), gn is an amplitude component of an n-th harmonic, θ is the position detection value, and ψn is an initial phase of the n-th harmonic.