Apparatus and method for calculating offset value for an electric sensor
First Claim
Patent Images
1. An apparatus for calculating an offset value for a current sensor of a magnetic flux detection type, comprising:
- a determining device which determines whether calculation of the offset value is permitted based on a current value detected by the current sensor, the determining device making the determination such that calculation of the offset value is permitted when the current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value and when an absolute value of the current value is within a predetermined range, wherein the predetermined range is based on the characteristics of a core of the current sensor; and
a calculating device which calculates the current value detected by the current sensor as the offset value when calculation of the offset value is permitted by the determining device.
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Abstract
Calculation of an offset value is permitted when a current value detected by an ammeter of a magnetic flux detection type is switched from a negative value to a positive value, or from a positive value to a negative value, and also a state where an absolute value of the current value is with in a predetermined range is continued for a predetermined time. When calculation of the offset value is permitted, the fact that an ignition switch is turned OFF is detected, and the current value detected by the ammeter is calculated as the offset value.
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Citations
10 Claims
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1. An apparatus for calculating an offset value for a current sensor of a magnetic flux detection type, comprising:
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a determining device which determines whether calculation of the offset value is permitted based on a current value detected by the current sensor, the determining device making the determination such that calculation of the offset value is permitted when the current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value and when an absolute value of the current value is within a predetermined range, wherein the predetermined range is based on the characteristics of a core of the current sensor; and a calculating device which calculates the current value detected by the current sensor as the offset value when calculation of the offset value is permitted by the determining device. - View Dependent Claims (2, 4, 5)
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3. An apparatus for calculating an offset value for a current sensor of a magnetic flux detection type, comprising:
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a determining device which determines whether calculation of the offset value is permitted based on a current value detected by the current sensor, the determining device making the determination such that calculation of the offset value is permitted when the current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value; and a calculating device which calculates the current value detected by the current sensor as the offset value when calculation of the offset value is permitted by the determining device, wherein the determining device makes a determination such that calculation of the offset value is permitted when the current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value, and when a state where an absolute value of the current value is within a predetermined range is continued for a predetermined time, wherein one of the predetermined range and the predetermined time is changed according to a change in a temperature of the current sensor.
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6. A method for correcting a current value detected by a current sensor of a magnetic flux detection type, comprising:
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determining whether calculation of an offset value is permitted, wherein calculation of the offset value is permitted when the current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value, and when an absolute value of the current value is within a predetermined range, wherein the predetermined range is based on the characteristics of a core of the current sensor; calculating the current value detected by the current sensor as the offset value when calculation of the offset value is permitted and; correcting the current value detected by the current sensor when detecting a charging or discharging current of a battery using the calculated offset value to account for a hysteresis characteristic of the core. - View Dependent Claims (7, 9, 10)
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8. A method for correcting a current value detected by a current sensor of a magnetic flux detection type, comprising:
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determining whether calculation of an offset value is permitted, wherein calculation of the offset value is permitted when a current value detected by the current sensor is switched from a negative value to a positive value, or from a positive value to a negative value, and when a state where an absolute value of the current value is within a predetermined range is continued for a predetermined time; calculating the current value detected by the current sensor as the offset value when calculation of the offset value is permitted, wherein one of the predetermined range and the predetermined time is changed according to a change in a temperature of the current; and correcting the current value detected by the current sensor when detecting a charging or discharging current of a battery using the calculated offset value to account for a hysteresis characteristic of a core of the current sensor.
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Specification