# US 12,181,310 B2 · Device and method for calibrating a magnetic angle sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,310 B2 - Document ID: US12181310B2 - Status: Granted - Kind: B2 - Application number: 17/740,594 - Filed: 2022-05-10 - Published: 2022-11-17 - Granted: 2024-12-31 - Earliest claimed: 2021-05-17 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Dirk Hammerschmidt - Web page: https://patentgrep.com/patent/US12181310B2 ## CPC - G01D 18/001: {Calibrating encoders} - G01D 5/14: influencing the magnitude of a current or voltage - G01D 18/008: {with calibration coefficients stored in memory} - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - 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 ## Abstract A method for calibrating a magnetic angle sensor includes measuring, for a plurality of angle positions within a 360° rotation of a measurement object, in each case a first sensor signal for a first magnetic field component and a second sensor signal for a second magnetic field component orthogonal to the first magnetic field component, wherein the first and second sensor signals are in each case 360° periodic and representable as a Fourier series with a Fourier component of a fundamental and a Fourier component of a harmonic; determining the Fourier component of the harmonic for the first and second sensor signals based on a difference between a trajectory defined by the measured first and second sensor signals and a circular path; and correcting the angle positions based on the Fourier component of the harmonic determined for the first and second sensor signals. ## Claims ### Claim 1 A method for calibrating a magnetic angle sensor, comprising: measuring, for each angle position of a plurality of angle positions within a 360° rotation of a measurement object, a first sensor signal for a first magnetic field component and a second sensor signal for a second magnetic field component aligned orthogonal to the first magnetic field component, wherein, over the plurality of angle positions, the first sensor signal and the second sensor signal are each 360° periodic and representable as a Fourier series with a Fourier component of a fundamental frequency and at least one Fourier component of a harmonic; determining the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal based on a difference between a 360° trajectory of an angle measurement vector, defined by the first sensor signal and the second sensor signal, and a circular path; and correcting the plurality of angle positions based on the at least one Fourier component of the harmonic determined for the first sensor signal and second sensor signal. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one Fourier component of the harmonic for the first sensor signal is determined independently of the at least one Fourier component of the harmonic for the second sensor signal. ### Claim 3 (depends on 2) The method of claim 2, wherein the at least one Fourier component of the harmonic for the first sensor signal comprises a Fourier component of an m-th order harmonic, and wherein the at least one Fourier component of the harmonic for the second sensor signal comprises a Fourier component of an n-th order harmonic, wherein m≥2, n≠m, and n≥2. ### Claim 4 (depends on 1) The method of claim 1, wherein correcting the plurality of angle positions comprises: correcting the first sensor signal corresponding to an angle position of the plurality of angle positions based on the at least one Fourier component of the harmonic determined for the first sensor signal in order to obtain a corrected first sensor signal; correcting the second sensor signal corresponding to the angle position based on the at least one Fourier component of the harmonic determined for the second sensor signal in order to obtain a corrected second sensor signal; and applying a tangent function to the corrected first sensor signal and the corrected second sensor signal. ### Claim 5 (depends on 1) The method of claim 1, wherein the at least one Fourier component of the harmonic for the first sensor signal the second sensor signal is determined by a compensation calculation method that minimizes a deviation between the circular path and the 360° trajectory of the angle measurement vector. ### Claim 6 (depends on 5) The method of claim 5, wherein the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal is determined by a least mean squares method. ### Claim 7 (depends on 1) The method of claim 1, further comprising: storing, after correcting the plurality of angle positions, the plurality of angle positions in a look-up table. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of angle positions within the 360° rotation of the measurement object satisfies a Nyquist-Shannon sampling theorem for the harmonic for the first sensor signal and the second sensor signal. ### Claim 9 (depends on 1) The method of claim 1, wherein the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal comprises a corresponding Fourier coefficient and phase value. ### Claim 10 (depends on 1) The method of claim 1, wherein the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal is determined by an error compensation of a mean value offset, amplitude synchronization, and orthogonality of the first sensor signal and the second sensor signal. ### Claim 11 A method for calibrating a magnetic angle sensor, comprising: measuring, for each angle position of a plurality of angle positions within a 360° rotation of a measurement object, a first sensor signal for a first magnetic field component and a second sensor signal for a second magnetic field component aligned orthogonal to the first magnetic field component, wherein, over the plurality of angle positions, the first sensor signal and the second sensor signal are each 360° periodic and representable as a Fourier series with a Fourier component of a fundamental frequency and at least one Fourier component of a harmonic; determining the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal based on a deviation between a circular path and a 360° trajectory of an angle measurement vector defined by the first and the second sensor signals supplemented by the at least one Fourier components of the harmonic for the first sensor signal and the second sensor signal; and correcting the plurality of angle positions based on the at least one Fourier component of the harmonic determined for the first sensor signal and the second sensor signal. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal is determined by a compensation calculation that minimizes the deviation between the circular path and the 360° trajectory of the angle measurement vector. ### Claim 13 A device for calibrating a magnetic angle sensor, the device comprising: a first magnetic field sensor configured to generate a first sensor signal in response to a first magnetic field component; a second magnetic field sensor configured to generate a second sensor signal in response to a second magnetic field component that is aligned orthogonal to the first magnetic field component; and a processing circuit configured to: measure, for each angle position of a plurality of angle positions within a 360° rotation of a measurement object, the first sensor signal and the second sensor signal, wherein, over the plurality of angle positions, the first sensor signal and the second sensor signal are each 360° periodic and representable as a Fourier series with a Fourier component of a fundamental frequency and at least one Fourier component of a harmonic, determine the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal based on a difference between a 360° trajectory of an angle measurement vector defined by the measured first and the second sensor signals and a circular path, and correct the plurality of angle positions based on the at least one Fourier component of the harmonic determined for the first sensor signal and second sensor signal. ### Claim 14 (depends on 13) The device of claim 13, wherein: the first magnetic field sensor comprises a first bridge circuit comprising a first plurality of sensor elements, the first sensor signal is a first bridge voltage that corresponds to the first magnetic field component, and the second magnetic field sensor comprises a second bridge circuit comprising a second plurality of sensor elements, the second sensor signal is a second bridge voltage that corresponds to the second magnetic field component. ### Claim 15 (depends on 13) The device of claim 13, wherein the at least one Fourier component of the harmonic for the first sensor signal is determined independently of the at least one Fourier component of the harmonic for the second sensor signal. ### Claim 16 (depends on 15) The device of claim 15, wherein the at least one Fourier component of the harmonic for the first sensor signal comprises a Fourier component of an m-th order harmonic, and wherein the at least one Fourier component of the harmonic for the second sensor signal comprises a Fourier component of an n-th order harmonic, wherein m≥2, n≠m, and n≥2. ### Claim 17 (depends on 13) The device of claim 13, wherein, to correct the plurality of angle positions, the processing circuit is configured to: correct the first sensor signal corresponding to an angle position of the plurality of angle positions based on the at least one Fourier component of the harmonic determined for the first sensor signal in order to obtain a corrected first sensor signal; correct the second sensor signal corresponding to the angle position based on the at least one Fourier component of the harmonic determined for the second sensor signal in order to obtain a corrected second sensor signal; and apply a tangent function to the corrected first sensor signal and the corrected second sensor signal. ### Claim 18 (depends on 13) The device of claim 13, wherein the at least one Fourier component of the harmonic for the first sensor signal the second sensor signal is determined by a compensation calculation method. ### Claim 19 (depends on 13) The device of claim 13, wherein the at least one Fourier component of the harmonic for the first sensor signal and the second sensor signal is determined by a least mean squares method. ### Claim 20 (depends on 13) The device of claim 13, wherein the processing circuit is further configured to: store, after correcting the plurality of angle positions, the plurality of angle positions in a look-up table.