# US 11,442,121 B2 · HEV robust algorithms for magnetic speed sensor for engine applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,121 B2 - Document ID: US11442121B2 - Status: Granted - Kind: B2 - Application number: 17/063,961 - Filed: 2020-10-06 - Published: 2021-01-21 - Granted: 2022-09-13 - Earliest claimed: 2018-09-25 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Simone Fontanesi; Klaus Grambichler; Tobias Werth - Web page: https://patentgrep.com/patent/US11442121B2 ## CPC - G01R 33/09: Magnetoresistive devices - G01R 33/091: {Constructional adaptation of the sensor to specific applications} - G01P 3/00: Measuring linear or angular speed; Measuring differences of linear or angular speeds (G01P5/00 - G01P11/00 take precedence; {direction and speed indication G01P13/045}; counting mechanisms G06M) - G01P 3/487: delivered by rotating magnets - G01R 33/025: Compensating stray fields {(G01R33/0017 takes precedence)} - G01R 33/072: {Constructional adaptation of the sensor to specific applications} - G01R 33/0094: {Sensor arrays} - G01R 33/038: using permanent magnets, e.g. balances, torsion devices - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract Magnetic field sensors and sensing methods are provided. A magnetic sensor module is configured to measure a magnetic field whose magnitude oscillates between a first extrema and a second extrema. The magnetic sensor module includes a magnetic sensor configured to generate measurement values in response to sensing the magnetic field, and a sensor circuit. The sensor circuit is configured to generate a measurement signal based on the measurement values, adjust an offset of the measurement signal according to an offset update algorithm and a first characteristic of the measurement signal, generate a pulsed output signal having pulses that are generated based on the adjusted measurement signal crossing the switching threshold, and selectively enable and disable the offset update algorithm based on a second characteristic of the measurement signal. ## Claims ### Claim 1 A magnetic sensor module configured to measure a magnetic field whose magnitude oscillates between a first extrema and a second extrema, the magnetic sensor module comprising: a magnetic sensor including a plurality of sensor elements configured to generate measurement values in response to sensing the magnetic field; and a sensor circuit configured to: receive the measurement values from at least one of the plurality of sensor elements, and generate a measurement signal based on the measurement values received from the at least one of the plurality of sensor elements, measure a first characteristic of the measurement signal and adjust an offset of the measurement signal according to an offset update algorithm based on the measured first characteristic of the measurement signal, compare the adjusted measurement signal to a switching threshold, and generate a pulsed output signal having pulses that are generated based on the adjusted measurement signal crossing the switching threshold, measure a second characteristic of the measurement signal, and selectively enable and disable the offset update algorithm based on at least the second characteristic of the measurement signal. ### Claim 2 (depends on 1) The magnetic sensor module of claim 1, wherein the first characteristic of the measurement signal is an average value of at least one first extrema of the measurement signal and at least one second extrema of the measurement signal. ### Claim 3 (depends on 1) The magnetic sensor module of claim 1, wherein: the second characteristic of the measurement signal is a frequency of the measurement signal, and the sensor circuit is configured to measure the frequency of the measurement signal, compare the frequency of the measurement signal to a frequency threshold, and disable the offset update algorithm on a condition that the frequency of the measurement signal is less than the frequency threshold. ### Claim 4 (depends on 3) The magnetic sensor module of claim 3, wherein the sensor circuit is configured to enable the offset update algorithm on a condition that the frequency of the measurement signal is equal to or greater than the frequency threshold. ### Claim 5 (depends on 3) The magnetic sensor module of claim 3, wherein: the sensor circuit is configured detect a rotation direction of the magnetic field, count a number of consecutive pulses of the pulsed output signal that occur in a same rotation direction of the magnetic field, compare the number of consecutive pulses to a switching event threshold, and disable the offset update algorithm on a condition that the number of consecutive pulses is less than the switching event threshold. ### Claim 6 (depends on 5) The magnetic sensor module of claim 5, wherein: the sensor circuit is configured to enable the offset update algorithm on a condition that the frequency of the measurement signal is equal to or greater than the frequency threshold and on a condition that the number of consecutive pulses is equal to or greater than the switching event threshold. ### Claim 7 (depends on 1) The magnetic sensor module of claim 1, wherein: the second characteristic of the measurement signal is a number of consecutive extrema of the measurement signal that occur in a same rotation direction of the magnetic field, wherein the sensor circuit is configured detect a rotation direction of the magnetic field, count the number of consecutive extrema of the measurement signal that occur in the same rotation direction of the magnetic field, compare the number of consecutive extrema to a switching event threshold, and disable the offset update algorithm on a condition that the number of consecutive extrema is less than the switching event threshold. ### Claim 8 (depends on 7) The magnetic sensor module of claim 7, wherein the sensor circuit is configured to enable the offset update algorithm on a condition that the number of consecutive extrema is equal to or greater than the switching event threshold. ### Claim 9 (depends on 1) The magnetic sensor module of claim 1, wherein: the sensor circuit includes a watchdog circuit that operates in parallel to a primary processing chain of the sensor circuit, the watchdog circuit being configured override a disabled state of the offset update algorithm set by the primary processing chain in order to re-enable the offset update algorithm, the watchdog circuit being configured detect a rotation direction of the magnetic field, count a number of consecutive pulses of the pulsed output signal that occur in a same rotation direction of the magnetic field, compare the number of consecutive pulses to a switching event threshold, and re-enable the offset update algorithm when the number of consecutive pulses is equal to the switching event threshold. ### Claim 10 A method of measuring a magnetic field whose magnitude oscillates between a first extrema and a second extrema, the method comprising: generating a measurement signal representing the measured magnetic field; measuring a first characteristic of the measurement signal; adjusting an offset of the measurement signal according to an offset update algorithm based on the measured first characteristic of the measurement signal; comparing the adjusted measurement signal to a switching threshold; generating a pulsed output signal having pulses that are generated based on the measurement signal crossing the switching threshold; measure a second characteristic of the measurement signal; and selectively enabling and disabling the offset update algorithm based on at least the second characteristic of the measurement signal. ### Claim 11 (depends on 10) The method of claim 10, wherein the first characteristic of the measurement signal is an average value of at least one first extrema of the measurement signal and at least one second extrema of the measurement signal. ### Claim 12 (depends on 10) The method of claim 10, wherein: the second characteristic of the measurement signal is a frequency of the measurement signal, the method further comprising: measuring the frequency of the measurement signal; comparing the frequency of the measurement signal to a frequency threshold; and disabling the offset update algorithm on a condition that the frequency of the measurement signal is less than the frequency threshold. ### Claim 13 (depends on 12) The method of claim 12, further comprising: enabling the offset update algorithm on a condition that the frequency of the measurement signal is equal to or greater than the frequency threshold. ### Claim 14 (depends on 12) The method of claim 12, further comprising: detecting a rotation direction of the magnetic field; counting a number of consecutive pulses of the pulsed output signal that occur in a same rotation direction of the magnetic field; comparing the number of consecutive pulses to a switching event threshold; and disabling the offset update algorithm on a condition that the number of consecutive pulses is less than the switching event threshold. ### Claim 15 (depends on 14) The method of claim 14, further comprising: enabling the offset update algorithm on a condition that the frequency of the measurement signal is equal to or greater than the frequency threshold and on a condition that the number of consecutive pulses is equal to or greater than the switching event threshold. ### Claim 16 (depends on 10) The method of claim 10, wherein: the second characteristic of the measurement signal is a number of consecutive extrema of the measurement signal that occur in a same rotation direction of the magnetic field, the method further comprising: detecting a rotation direction of the magnetic field; counting the number of consecutive extrema of the measurement signal that occur in the same rotation direction of the magnetic field; comparing the number of consecutive extrema to a switching event threshold; and disabling the offset update algorithm on a condition that the number of consecutive extrema is less than the switching event threshold. ### Claim 17 (depends on 16) The method of claim 16, further comprising: enabling the offset update algorithm on a condition that the number of consecutive extrema is equal to or greater than the switching event threshold. ### Claim 18 (depends on 10) The method of claim 10, further comprising: disabling the offset update algorithm by a primary processing chain; operating a watchdog function in parallel to the primary processing chain; and overriding a disabled state of the offset update algorithm set by a primary processing chain via the watchdog function to re-enable the offset update algorithm.