US 7,743,519 B2 · Sensor module, method of correction therefor, and mobile object including the sensor module

Abstract

A sensor module maintaining high detection accuracy. Correction data of a detected magnetic field is updated only in a case that a fluctuation band acquired from an output signal of an acceleration sensor is less than a threshold value and a difference between an azimuth angle acquired from an output signal of a terrestrial magnetism sensor and an inclination angle acquired from an output signal of acceleration sensor is less than the threshold value. Therefore, the correction data is updated only in a case that a magnetic field at a position of a mobile object is stably detected, and an accuracy of the correction data can be maintained.

Claims20

Dependent claims

A sensor module mounted on a mobile object, comprising:

a magnetic sensor having at least two magnetic field detecting axes and that outputs first azimuth data indicating a first direction that a reference portion in the mobile object faces based on magnetic information;
a motion sensor detecting at least one of an acceleration motion or angular motion of the mobile object and configured to output a second azimuth data indicating a second direction that the reference portion in the mobile object faces based on the acceleration motion or angular motion;
and
a processing device that stores correction data to correct the magnetic information used by the magnetic sensor, and that updates that stored correction data when a difference between the first azimuth data and the second azimuth data is less than a first threshold value.

1 more element

A correction method for correcting magnetic information for a sensor module mounted on a mobile object including a magnetic sensor including at least two magnetic field detecting axes and a motion sensor detecting at least one of an acceleration or angular motion of the mobile object, the method comprising:

calculating a first azimuth data indicating a direction that a reference portion of the mobile object faces based on magnetic information from the magnetic sensor;
calculating a second azimuth data indicating a direction that the reference portion of the mobile object faces based on information from at least the motion sensor;
judging whether a difference between the first azimuth data and the second azimuth data is less than a first threshold value or not;
updating a stored correction data for correcting magnetic data in a case the difference is less than the first threshold value;
and
correcting the magnetic information based on the correction data.

3 more elements

Dependencies are inferred from the claim text.

Sensor module, method of correction therefor, and mobile object including the sensor module

Life of this patent

Sensor module, method of correction therefor, and mobile object including the sensor module

Life of this patent

Abstract

Claims20