# US 12,215,973 B2 · Magnetic-field-based angle sensor system with stray field compensation and method for stray field compensation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,973 B2 - Document ID: US12215973B2 - Status: Granted - Kind: B2 - Application number: 17/406,496 - Filed: 2021-08-19 - Published: 2022-02-24 - Granted: 2025-02-04 - Earliest claimed: 2020-08-20 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Benjamin Kollmitzer; Wolfgang Granig; Udo Hafner; Manuel Gillinger - Web page: https://patentgrep.com/patent/US12215973B2 ## CPC - G01B 7/30: for measuring angles or tapers; for testing the alignment of axes - G01D 5/145: {influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06)} - G01D 5/16: by varying resistance - G01D 5/24485: {using other sensors} - G01D 5/2451: {Incremental encoders (G01D5/2454 takes precedence)} - G01D 18/001: {Calibrating encoders} - G01R 33/07: Hall effect devices - G01R 33/09: Magnetoresistive devices - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - 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 - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A magnetic-field-based angle sensor system includes a stator component and a rotor component rotatable relative thereto, a magnetic field sensor operating in saturation operation and a magnetic field sensor operating in linear operation, wherein the magnetic field sensor operating in saturation operation is configured to determine a rotation angle of the rotor component relative to the stator component, and wherein the magnetic field sensor operating in linear operation is configured to ascertain an external magnetic stray field acting on the angle sensor system. The angle sensor system further includes a control device configured, based on the ascertained external magnetic stray field, to compensate for a stray-field-dependent measurement deviation in the determination of the rotation angle carried out. ## Claims ### Claim 1 A magnetic-field-based angle sensor system, comprising: a stator component; a rotor component configured to rotate relative to the stator component, wherein the rotor component comprises a multipole magnet; a first magnetic field sensor configured to: operate in a saturation operation, and determine a rotation angle of the rotor component around an axis perpendicular to a surface of the stator component based on a magnetic field of the multipole magnet; a second magnetic field sensor configured to: operate in a linear operation, and ascertain an external magnetic stray field acting on the magnetic-field-based angle sensor system; and a controller configured to; perform an autocalibration on output signals of the second magnetic field sensor to ascertain stray-field-dependent compensation parameters corresponding to the external magnetic stray field, and compensate for a stray-field-dependent measurement deviation in the determination of the rotation angle based on the stray-field-dependent compensation parameters. ### Claim 2 (depends on 1) The magnetic-field-based angle sensor system of claim 1, wherein the first magnetic field sensor is a magnetoresistive sensor which utilizes an anisotropic magneto-resistive effect (AMR), a giant magnetoresistance effect (GMR), a colossal magnetoresistive effect (CMR), or a tunneling magnetoresistance effect (TMR). ### Claim 3 (depends on 1) The magnetic-field-based angle sensor system of claim 1, wherein the second magnetic field sensor is a Hall effect sensor. ### Claim 4 (depends on 3) The magnetic-field-based angle sensor system of claim 3, wherein the Hall effect sensor is configured as a vertical Hall effect plate arranged vertically with respect to the first magnetic field sensor. ### Claim 5 (depends on 1) The magnetic-field-based angle sensor system of claim 1, wherein the stray-field-dependent compensation parameters include at least one of offset information or amplitude information of the output signals. ### Claim 6 (depends on 5) The magnetic-field-based angle sensor system of claim 5, wherein the stray-field-dependent compensation parameters include a ratio between the offset information and the amplitude information, in accordance with: the offset information/the amplitude information. ### Claim 7 (depends on 5) The magnetic-field-based angle sensor system of claim 5, wherein the controller is further configured to: apply the stray-field-dependent compensation parameters to output signals of the first magnetic field sensor to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle; and carry out an angle calculation indicating the rotation angle based on the output signals of the first magnetic field sensor. ### Claim 8 (depends on 7) The magnetic-field-based angle sensor system of claim 7, wherein the controller is configured to: carry out an amplitude-phase-offset correction of the output signals of the first magnetic field sensor before the stray-field-dependent compensation parameters are applied to the output signals of the first magnetic field sensor, wherein at least one of an amplitude offset compensation or a phase offset compensation is applied to the output signals of the first magnetic field sensor to carry out the amplitude-phase-offset correction. ### Claim 9 (depends on 5) The magnetic-field-based angle sensor system of claim 5, wherein the controller is configured to: carry out an angle calculation indicating the rotation angle based on output signals of the first magnetic field sensor, and apply the stray-field-dependent compensation parameters to a result of the angle calculation to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle. ### Claim 10 (depends on 9) The magnetic-field-based angle sensor system of claim 9, wherein the controller is further configured to: carry out an amplitude-phase-offset correction of the output signals of the first magnetic field sensor before the stray-field-dependent compensation parameters is applied to the result of the angle calculation, wherein at least one of an amplitude offset compensation or a phase offset compensation is applied to the output signals of the first magnetic field sensor to carry out the amplitude-phase-offset correction. ### Claim 11 A method, comprising: determining, by a magnetic-field-based angle sensor system using a first magnetic field sensor operating in a saturation operation, a rotation angle of a rotor component around an axis perpendicular to a surface of a stator component based on a magnetic field of a multipole magnet, wherein the rotor component is rotatable relative to the stator component and comprises the multipole magnet; ascertaining, by the magnetic-field-based angle sensor system using a second magnetic field sensor operating in a linear operation, an external magnetic stray field acting on the magnetic-field-based angle sensor system; performing, by the magnetic-field-based angle sensor system, an autocalibration of output signals of the second magnetic field sensor to ascertain stray-field-dependent compensation parameters corresponding to the external magnetic stray field; and compensating, by the magnetic-field-based angle sensor system, for a stray-field-dependent measurement deviation in the determination of the rotation angle based on the stray-field-dependent compensation parameters. ### Claim 12 (depends on 11) The method of claim 11, wherein the stray-field-dependent compensation parameters contain at least one of offset information or amplitude information of the output signals of the second magnetic field sensor. ### Claim 13 (depends on 12) The method of claim 12, further comprising: applying the stray-field-dependent compensation parameters to output signals of the first magnetic field sensor to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle; and performing, based on applying the stray-field-dependent compensation parameters, an angle calculation indicating the rotation angle based on the output signals of the first magnetic field sensor. ### Claim 14 (depends on 13) The method of claim 13, further comprising: performing an autocalibration of the output signals of the first magnetic field sensor before applying the stray-field-dependent compensation parameters to the output signals of the first magnetic field sensor, wherein at least one of an amplitude offset compensation or a phase offset compensation is applied to the output signals of the first magnetic field sensor when performing the autocalibration. ### Claim 15 (depends on 13) The method of claim 13, further comprising: performing an autocalibration of the output signals of the first magnetic field sensor before applying the stray-field-dependent compensation parameters to a result of the angle calculation, wherein at least one of an amplitude offset compensation or a phase offset compensation is applied to the output signals of the first magnetic field sensor when performing the autocalibration. ### Claim 16 (depends on 12) The method of claim 12, further comprising: performing an angle calculation indicating the rotation angle based on output signals of the first magnetic field sensor, and applying the stray-field-dependent compensation parameters to a result of the angle calculation to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle. ### Claim 17 A non-transitory computer-readable medium comprising a computer program having a program code for causing a programmable hardware device to: determine, using a first magnetic field sensor operating in a saturation operation, a rotation angle of a rotor component around an axis perpendicular to a surface of a stator component based on a magnetic field of a multipole magnet, wherein the rotor component is rotatable relative to the stator component and comprises the multipole magnet; ascertain, using a second magnetic field sensor operating in a linear operation, an external magnetic stray field acting on the programmable hardware device; perform an autocalibration of output signals of the second magnetic field sensor to ascertain stray-field-dependent compensation parameters corresponding to the external magnetic stray field; and compensate for a stray-field-dependent measurement deviation in the determination of the rotation angle based on the stray-field-dependent compensation parameters. ### Claim 18 (depends on 17) The non-transitory computer-readable medium of claim 17, wherein the stray-field-dependent compensation parameters contain at least one of offset information or amplitude information of the output signals of the second magnetic field sensor. ### Claim 19 (depends on 18) The non-transitory computer-readable medium of claim 18, wherein the program code further causes the programmable hardware device to: apply the stray-field-dependent compensation parameters to output signals of the first magnetic field sensor to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle; and perform, based on applying the stray-field-dependent compensation parameters, an angle calculation indicating the rotation angle based on the output signals of the first magnetic field sensor. ### Claim 20 (depends on 18) The non-transitory computer-readable medium of claim 18, wherein the program code further causes the programmable hardware device to: perform an angle calculation indicating the rotation angle based on output signals of the first magnetic field sensor, and apply the stray-field-dependent compensation parameters to a result of the angle calculation to compensate for the stray-field-dependent measurement deviation in the determination of the rotation angle.