Gyro sensor calibration method

Patent metadata

Field	Value
Publication number	US-11454516-B2
Application number	US-201917059228-A
Country	US
Kind code	B2
Filing date	May 17, 2019
Priority date	Jun 4, 2018
Publication date	Sep 27, 2022
Grant date	Sep 27, 2022

Abstract

In a method of calibrating a gyro sensor mounted on a vehicle for measuring an angular velocity in a rotating direction generated about an axis of a vertical direction, a lateral shift amount detection process of detecting lateral shift amounts of the vehicle with respect to magnetic markers laid in a road, an azimuth estimation process of estimating, when the vehicle passes over a laying location where two magnetic markers are laid, an azimuth of the vehicle by a calculation process with the lateral shift amounts with respect to the two magnetic markers taken as input values, and a calibration process of calibrating the gyro sensor by using the azimuth of the vehicle estimated by the azimuth estimation process, are performed.

First claim

The invention claimed is:

1. A gyro sensor calibration method in a vehicle including a gyro sensor which measures an angular velocity in a rotating direction generated about an axis of a vertical direction, the method comprising:
a lateral shift amount detection process of detecting lateral shift amounts of the vehicle with respect to magnetic markers laid in a road; an azimuth estimation process of estimating, when the vehicle passes over a laying location where at least two of the magnetic markers are laid,
an azimuth of the vehicle by a calculation process with the lateral shift amounts detected by the lateral shift amount detection process for the at least two of the magnetic markers taken as input values;
a calibration process of calibrating the gyro sensor by using the azimuth of the vehicle estimated by the azimuth estimation process; and
an integration process of temporally integrating measurement values of the gyro sensor while the vehicle passes over two of the laying locations, the two of the laying locations being separate and along the road, and wherein at least two of the magnetic markers are laid at each of the two of the laying locations, wherein
in the calibration process, the gyro sensor is calibrated so that a difference between a vehicle rotation angle, which is a difference in azimuths of the vehicle estimated by the azimuth estimation process at each of the two of the laying locations, and a measured rotation angle, which is an integrated value by the integration process, gets smaller than before performing the calibration process.

2. A gyro sensor calibration method in a vehicle including a gyro sensor which measures an angular velocity in a rotating direction generated about an axis of a vertical direction, the method comprising:
a lateral shift amount detection process of detecting lateral shift amounts of the vehicle with respect to magnetic markers laid in a road;
an azimuth estimation process of estimating, when the vehicle passes over a laying location where at least two of the magnetic markers are laid, an azimuth of the vehicle by a calculation process with the lateral shift amounts detected by the lateral shift amount detection process for the at least two of the magnetic markers taken as input values; and
a calibration process of calibrating the gyro sensor by using the azimuth of the vehicle estimated by the azimuth estimation process,
wherein the calibration process is a process in which, when the vehicle passes over the laying location, the laying location being provided on a linear road, when a differential value between said lateral shift amounts is equal to or smaller than a predetermined value, a value of the angular velocity measured by the gyro sensor is brought closer to zero.

3. The gyro sensor calibration method according to claim 1 , wherein an information providing part is annexed to at least one of the magnetic markers arranged in the laying location, and the information providing part provides marker azimuth information identifying a direction of a line segment connecting the at least two of the magnetic markers arranged in the laying location.

4. The gyro sensor calibration method according to claim 3 , wherein the information providing part is a wireless tag attached to the at least one of the magnetic markers.

5. The gyro sensor calibration method according to claim 1 , wherein an information providing part is annexed to at least one of the magnetic markers arranged in the laying location, and the information providing part provides marker azimuth information identifying a direction of a line segment connecting the at least two of the magnetic markers arranged in the laying location.

6. The gyro sensor calibration method according to claim 5 , wherein the information providing part is a wireless tag attached to the at least one of the magnetic markers.

7. The gyro sensor calibration method according to claim 2 , wherein an information providing part is annexed to at least one of the magnetic markers arranged in the laying location, and the information providing part provides marker azimuth information identifying a direction of a line segment connecting the at least two of the magnetic markers arranged in the laying location.

8. The gyro sensor calibration method according to claim 7 , wherein the information providing part is a wireless tag attached to the at least one of the magnetic markers.

9. The gyro sensor calibration method according to claim 1 , wherein in the calibration process, the gyro sensor is calibrated so that the difference between the vehicle rotation angle and the measured rotation angle becomes zero.

10. The gyro sensor calibration method according to claim 3 , wherein the marker azimuth information indicates the direction of the line segment connecting the at least two of the magnetic markers arranged in the laying location.

11. The gyro sensor calibration method according to claim 7 , wherein the marker azimuth information indicates the direction of the line segment connecting the at least two of the magnetic markers arranged in the laying location.

Assignees

• Aichi Steel Corp

Inventors

• Yamamoto Michiharu
• Nagao Tomohiko
• Aoyama Hitoshi

Classifications

• G01C21/16

  by integrating acceleration or speed, i.e. inertial navigation · CPC title

• G01C25/005 Primary

  initial alignment, calibration or starting-up of inertial devices · CPC title

• G01C21/28

  with correlation of data from several navigational instruments · CPC title

• G01C21/06

  involving measuring of drift angle; involving correction for drift · CPC title

• G05D1/027

  comprising intertial navigation means, e.g. azimuth detector (inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165) · CPC title