Rotation angle detection apparatus having function of detecting entry of foreign substance based on frequency characteristic of signals
First Claim
1. A rotation angle detection apparatus comprising:
- a rotator and a track, the rotator configured to rotate the track around a rotation axis;
a detector disposed in correspondence with the track; and
a processor configured to;
calculate a rotation angle of a rotation axis based on signals generated by the detector;
calculate the rotation speed of the rotation axis based on the signals; and
detect an abnormality based on the signals, by;
calculating a frequency characteristic of the signals;
storing the signals generated from the track per revolution of the rotator;
calculating a signal frequency that is the product of the stored signals and the calculated rotation speed; and
detecting the abnormality, when the frequency characteristic includes a component of a higher order than the signal frequency.
1 Assignment
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Accused Products
Abstract
A rotation angle detection apparatus includes a rotator having a track unit to detect the rotation angle of a rotation axis; a detection unit disposed in correspondence with the track unit; a rotation angle calculation unit for calculating the rotation angle of the rotation axis based on signals generated by the detection unit; a rotation speed calculation unit for calculating the rotation speed of the rotation axis; and an abnormality detection unit for detecting an abnormality. The abnormality detection unit includes a frequency analyzing unit for calculating the frequency characteristic of the signals; a storage unit for storing the number of the signals per revolution of the rotator; a signal frequency calculation unit for calculating a signal frequency; and a determination unit for detecting the abnormality in the detection apparatus, when the frequency characteristic includes a component of a higher order than the signal frequency.
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Citations
1 Claim
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1. A rotation angle detection apparatus comprising:
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a rotator and a track, the rotator configured to rotate the track around a rotation axis; a detector disposed in correspondence with the track; and a processor configured to; calculate a rotation angle of a rotation axis based on signals generated by the detector; calculate the rotation speed of the rotation axis based on the signals; and detect an abnormality based on the signals, by; calculating a frequency characteristic of the signals; storing the signals generated from the track per revolution of the rotator; calculating a signal frequency that is the product of the stored signals and the calculated rotation speed; and detecting the abnormality, when the frequency characteristic includes a component of a higher order than the signal frequency.
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Specification