| 摘要 |
The present invention provides an absolute angle detecting apparatus capable of accurately detecting the absolute angle of a rotating body even when positional deviation occurs in the switching position of an arc tangent signal obtained from a sine signal and a cosine signal that are output from a magnetic sensor. An absolute angle detecting apparatus according to an embodiment of the invention includes: a rotating body A; a rotating magnet 10 that rotates with the rotation of the rotating body A; and a magnetic sensor 11 that outputs signals sin¸, cos¸, -sin¸, and -cos¸ using a variation in the direction of a magnetic field according to the rotation angle ¸ of the rotating magnet 10. The first and second arc tangent signals tan -1 ¸ having phases that deviate from each other by a quarter of the period of each output signal of the magnetic sensor are generated on the basis of the output signals of the magnetic sensor. The absolute angle detecting apparatus generates a sawtooth signal without using the vicinities of the switching positions of the two arc tangent signals tan -1 ¸, and detects the absolute angle of the rotating body A within one rotation of the rotating body A, on the basis of the sawtooth signal.
|
