| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized encoder of light weighted for a three-phase AC servo motor capable of generating A-, B-phase signals expressing a rotation position, and U-, V-, W-phase magnetic pole signals of three phases expressing motor pole positions. SOLUTION: This encoder 20 attached to a rotary shaft 5 of the AC servo motor 1 has a single rotary disk 22 attracted magnetically in each of two poles, magnetic sensors 23X, 23Y for outputting X-, Y-phase signals different by 90°in phases accompanying the rotation, and a signal processing part 25. In the signal processing part 25, a rotation angleθa of a motor rotor 8 is computed at a prescribed period based on the X-, Y-phase signals, the U-, V-, W-phase magnetic pole signals of the three phases different by 120°in the phases are generated, based on the number M of magnetic poles in the motor 1, a magnetic pole reference angleθo and the rotor angleθa, and the A-phase signal and the B-phase signal of a predetermined pulse period different by 90°in the phases are generated based on the the rotor angleθa. The encoder advantageous for reducing a size and a weight of the AC servo motor is realized since one set of the rotary disks and the magnetic sensors is enough to be arranged. COPYRIGHT: (C)2005,JPO&NCIPI
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