ROTATING FIELD SENSOR

摘要

A first, a second, and a third computing circuit respectively generate a first post-computation signal with a second harmonic component reduced as compared with first and second signals, a second post-computation signal with the second harmonic component reduced as compared with third and fourth signals, and a third post-computation signal with the second harmonic component reduced as compared with fifth and sixth signals. A fourth and a fifth computing circuit respectively generate a fourth post-computation signal with a third harmonic component reduced as compared with the first and second post-computation signals, and a fifth post-computation signal with the third harmonic component reduced as compared with the second and third post-computation signals. A sixth computing circuit determines a detected angle value based on the fourth and fifth post-computation signals.

主权项

1. A rotating field sensor configured to detect an angle that a direction of a rotating magnetic field in a reference position forms with respect to a reference direction, the rotating field sensor comprising:
first to sixth signal generation units configured to generate first to sixth signals, respectively, each of the first to sixth signals being responsive to the direction of the rotating magnetic field, each of the first to sixth signal generation units including at least one magnetic detection element; and an angle detection unit configured to generate a detected angle value based on the first to sixth signals, the detected angle value having a correspondence relationship with the angle that the direction of the rotating magnetic field in the reference position forms with respect to the reference direction, wherein each of the first to sixth signals contains: an ideal component that varies periodically with a predetermined signal period; an error component of a period of ½ the predetermined signal period; and an error component of a period of ⅓ the predetermined signal period, the ideal components of the first to sixth signals are different in phase from each other, an absolute value of a phase difference between the ideal component of the first signal and the ideal component of the second signal, an absolute value of a phase difference between the ideal component of the third signal and the ideal component of the fourth signal, and an absolute value of a phase difference between the ideal component of the fifth signal and the ideal component of the sixth signal are all greater than 150° and smaller than 210°, and the angle detection unit includes:
a first computing circuit configured to generate a first post-computation signal based on the first and second signals, the first post-computation signal containing a reduced error component of the period of ½ the predetermined signal period as compared with the first and second signals;a second computing circuit configured to generate a second post-computation signal based on the third and fourth signals, the second post-computation signal containing a reduced error component of the period of ½ the predetermined signal period as compared with the third and fourth signals;a third computing circuit configured to generate a third post-computation signal based on the fifth and sixth signals, the third post-computation signal containing a reduced error component of the period of ½ the predetermined signal period as compared with the fifth and sixth signals;a fourth computing circuit configured to generate a fourth post-computation signal based on the first and second post-computation signals, the fourth post-computation signal containing a reduced error component of the period of ⅓ the predetermined signal period as compared with the first and second post-computation signals;a fifth computing circuit generate a fifth post-computation signal based on the second and third post-computation signals, the fifth post-computation signal containing a reduced error component of the period of ⅓ the predetermined signal period as compared with the second and third post-computation signals; anda sixth computing circuit configured to determine the detected angle value based on the fourth and fifth post-computation signals.