Patent ID: 9509245
Filing Date: 2016-11-29
CPC Classification: H02P

Claim Text:
1. A control device for linear motor that controls a linear motor, the control device comprising: a section estimation unit that estimates which of a plurality of sections obtained by dividing magnetic pole positions from 0° to 360° includes a current magnetic pole position of the linear motor based on a movement direction of a mover by a plurality of pulse energizations; a magnetic pole position refinement unit that performs pulse energization while changing the estimated magnetic pole position by a first predetermined amount of change from any one of a minimum value and a maximum value of the section estimated by the section estimation unit to the other, and approximates the estimated magnetic pole position to the current magnetic pole position based on the movement of the mover when the pulse energization is performed; and a magnetic pole position detection unit that performs direct current excitation while changing the estimated magnetic pole position by a second amount of change smaller than the first amount of change and performs an acquisition of an amount of movement of the mover when the estimated magnetic pole position is changed by the second amount of change, after direct current excitation is performed at the estimated magnetic pole position approximated by the magnetic pole position refinement unit, sets the estimated magnetic pole position as the current magnetic pole position when the acquired amount of movement matches an amount of movement corresponding to the second amount of change, and repeat the acquisition when the acquired amount of movement does not match an amount of movement corresponding to the second amount of change.