# US 12,761,051 B2 · Rotation angle sensor and calibration method of rotation angle sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,051 B2 - Document ID: US12761051B2 - Status: Granted - Kind: B2 - Application number: 18/503,185 - Filed: 2023-11-07 - Published: 2024-05-16 - Granted: 2026-10-13 - Earliest claimed: 2022-11-16 - Assignees: Asahi Kasei Microdevices Corporation - Applicants: Asahi Kasei Microdevices Corporation - Inventors: Taiki Nakanishi; Takato Katayama - Web page: https://patentgrep.com/patent/US12761051B2 ## CPC - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - G01B 7/30: for measuring angles or tapers; for testing the alignment of axes - G01D 18/004: {Continuous recalibration} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract To provide a rotation angle sensor which outputs N periods (N>1) of a first signal of a first phase and a second signal of a second phase forming a predetermined phase angle with the first phase per single rotation of a rotating body. The rotation angle sensor includes a calibration parameter calculating part which calculates, in a mechanical angle of one angular range having a first mechanical angle different from a reference mechanical angle as its starting point, based on the first signal and the second signal, a calibration parameter which calibrates an error in a moving radius of the rotating body in the reference mechanical angle of the rotating body. The one angular range may have the first mechanical angle as its starting point and a second mechanical angle as its ending point. ## Claims ### Claim 1 A rotation angle sensor which outputs N periods (N>1) of a first signal of a first phase and a second signal of a second phase forming a predetermined phase angle with the first phase per single rotation of a rotating body, the rotation angle sensor comprising: a calibration parameter calculating part which calculates, in a mechanical angle of one angular range having a first mechanical angle different from a reference mechanical angle as its starting point, based on the first signal and the second signal, a calibration parameter which calibrates an error in a moving radius of the rotating body in the reference mechanical angle of the rotating body. ### Claim 2 (depends on 1) The rotation angle sensor according to claim 1, wherein the one angular range has the first mechanical angle as its starting point and a second mechanical angle as its ending point, and the first mechanical angle and the second mechanical angle are smaller than the reference mechanical angle. ### Claim 3 (depends on 2) The rotation angle sensor according to claim 2, wherein an angle of the moving radius in the second mechanical angle is 180° smaller than an angle of the moving radius in the reference mechanical angle. ### Claim 4 (depends on 2) The rotation angle sensor according to claim 2, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 5 (depends on 1) The rotation angle sensor according to claim 1, wherein the one angular range has the first mechanical angle as its starting point and a second mechanical angle as its ending point, and the first mechanical angle is smaller than the reference mechanical angle, and the second mechanical angle is greater than the reference mechanical angle. ### Claim 6 (depends on 5) The rotation angle sensor according to claim 5, wherein an angle of the moving radius in the first mechanical angle is 180° smaller than an angle of the moving radius in the reference mechanical angle. ### Claim 7 (depends on 5) The rotation angle sensor according to claim 5, further comprising a predicting part which predicts the first signal and the second signal from the reference mechanical angle to the second mechanical angle, wherein the calibration parameter calculating part calculates the calibration parameter, in an angular range from the reference mechanical angle to the second mechanical angle, based on the first signal and the second signal predicted by the predicting part. ### Claim 8 (depends on 5) The rotation angle sensor according to claim 5, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 9 (depends on 1) The rotation angle sensor according to claim 1, wherein the one angular range has the first mechanical angle as its starting point and a second mechanical angle as its ending point, and the first mechanical angle and the second mechanical angle are greater than the reference mechanical angle. ### Claim 10 (depends on 9) The rotation angle sensor according to claim 9, wherein an angle of the moving radius in the first mechanical angle is 180° greater than an angle of the moving radius in the reference mechanical angle. ### Claim 11 (depends on 9) The rotation angle sensor according to claim 9, further comprising a predicting part which predicts the first signal and the second signal from the reference mechanical angle to the second mechanical angle, wherein the calibration parameter calculating part calculates the calibration parameter, in an angular range from the reference mechanical angle to the second mechanical angle, based on the first signal and the second signal predicted by the predicting part. ### Claim 12 (depends on 9) The rotation angle sensor according to claim 9, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 13 (depends on 1) The rotation angle sensor according to claim 1, wherein the one angular range is an angular range of 360° of the moving radius having the first mechanical angle as its starting point. ### Claim 14 (depends on 13) The rotation angle sensor according to claim 13, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 15 (depends on 1) The rotation angle sensor according to claim 1, further comprising a determining part, wherein the reference mechanical angle is a third mechanical angle of the rotating body or greater, the first signal being maximum in the third mechanical angle, and is a fourth mechanical angle of the rotating body or smaller, the first signal being minimum in the fourth mechanical angle, and the determining part determines the first mechanical angle based on a first angle which is a differential between the reference mechanical angle and the third mechanical angle or a second angle which is a differential between the reference mechanical angle and the fourth mechanical angle. ### Claim 16 (depends on 15) The rotation angle sensor according to claim 15, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 17 (depends on 1) The rotation angle sensor according to claim 1, further comprising a moving radius computing part which computes an angle and a size of the moving radius of the rotating body based on the first signal and the second signal, wherein the calibration parameter calculating part calculates the calibration parameter based on the angle and the size of the moving radius of the rotating body computed by the moving radius computing part. ### Claim 18 A calibration method of a rotation angle sensor which outputs N periods (N>1) of a first signal of a first phase and a second signal of a second phase forming a predetermined phase angle with the first phase per single rotation of a rotating body, the calibration method comprising: calculating, by a calibration parameter calculating part, in a mechanical angle of one angular range having a first mechanical angle different from a reference mechanical angle as its starting point, based on the first signal and the second signal, a calibration parameter which calibrates an error in a moving radius of the rotating body in the reference mechanical angle of the rotating body.