Correcting method and correcting errors in a terrestrial magnetism heading sensor

• US 4,862,398 A
• Filed: 11/13/1987
• Issued: 08/29/1989
• Est. Priority Date: 11/18/1986
• Status: Expired due to Term

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Honoki, Yasuhiro, Shimizu, Toshiyuki, Shimizu, Osamu, Tenmoku, Kenji, Mitoh, Kunihiko
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/119,966
• Time in Patent Office: 655 Days
• Field of Search: 364/449, 364/454, 364/457, 364/571.05, 33/356, 33/357, 33/361, 33/363 R, 33/363 Q
• US Class Current: 702/93
• CPC Class Codes: G01C 17/38 Testing, calibrating, or compensating of compasses

Abstract

In a location detecting apparatus which detects the location of a moving body on the basis of the heading signal from a terrestrial magnetism heading sensor attached to the moving body and the rotational angle signal from a rotational angle sensor attached to the moving body, a correcting method for correcting errors in a terrestrial magnetism heading sensor, comprising the steps of: detecting the amount of a heading change of the moving body that is made when the moving body turns a curve, and detecting a magnetized amount of the moving body on the basis of the detected amount of a heading change, an output from the terrestrial magnetism heading sensor before the heading change is made and an output from the terrestrial magnetism heading sensor after the heading change is made.

Claims

1. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body and a rotational angle signal from a rotational angle sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting an amount of a heading change of said moving body that is made when said moving body turns a curve, on the basis of said rotational angle signal from said rotational angle sensor,

detecting a magnetized amount of said moving body on the basis of the detected amount of said heading change, an output from said terrestrial magnetism heading sensor before said heading change is made and an output from said terrestrial magnetism heading sensor after said heading change is made, and

correcting said heading single on the basis of the detected magnetized amount.

3. A correcting method as set forth on claim 1 or 2 in which said moving body comprises a vehicle.

2. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting an amount of a heading change of said moving body that is made when said moving body turns a curve, by calculating a difference between a present location and a previous location of said moving body which is located on a road map represented by road map data,

detecting a magnetized amount of said moving body on the basis of the detected amount of said heading change, an output from said terrestrial magnetism heading sensor before said heading change is made an output from said terrestrial magnetism heading sensor after said heading change is made, and

correcting said heading signal on the basis of the detected magnetized amount.

4. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body and a rotational angle signal from a rotational angle sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting an amount of a heading change in said moving body on the basis of said rotational angle signal,

detecting a magnetized amount of said moving body on the basis of the detected amount of the heading change of said moving body and a radius of a terrestrial magnetism heading circle, and

correcting said heading signal on the basis of the detected magnetized amount.

7. A corresponding method as set forth in claim 4, 5, or 6 in which said moving body comprises a vehicle.

5. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting an amount of a heading change of said moving body, by calculating a difference between a present location and a previous location of said moving body which is located on a road map represented by road map data,

detecting a magnetized amount of said moving body on the basis of the detected amount of the heading change of said moving body and a radius of a terrestrial magnetism heading circle, and

correcting said heading signal on the basis of the detected magnetized amount.

6. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

determining whether said moving body is located on a road represented in road map data, and in the case that said moving body is located on said road, detecting the amount of heading change of said moving body on the basis of a present location and a previous location of said moving body represented by said road map data, and in the case that said moving body is not located on said road, detecting the amount of heading change of said moving body on the basis of a rotational angle signal from a rotational angle sensor,

detecting a magnetized amount of said moving body on the basis of the detected amount of the heading change of said moving body and a radius of a terrestrial magnetism heading circle, and

correcting said heading signal on the basis of the detected magnetized amount.

8. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body and a rotational angle signal from a rotational angle sensor attached to the moving body, a correction method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting a magnetized amount of said moving body on the basis of a heading of said moving body and a radius of a terrestrial magnetism heading circle, and if said moving body curves, detecting the amount of a heading change of said moving body on the basis of said rotational angle signal and detecting said magnetized amount of said moving body on the basis of the detected amount of heading change when said moving body curves and two output signals from said terrestrial magnetism heading sensor before and after said moving body curves, and

correcting said heading signal on the basis of the detected magnetized amount.

9. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting a magnetized amount of said moving body on the basis of a heading of said moving body and a radius of a terrestrial magnetism heading circle, and if said moving body curves, detecting an amount of a heading change of said moving body by calculating the difference between the present location and the previous location of said moving body which is located on a road map represented by road map data and detecting a magnetized amount of said moving body on the basis of the detected amount of heading change when said moving body curves and two output signals from said terrestrial magnetism heading sensor before and after said moving body curves, and

correcting said heading signal on the basis of the detected magnetized amount.

10. In a location detecting apparatus which detects a location of a moving body on the basis of a heading signal from a terrestrial magnetism heading sensor attached to the moving body, a correcting method for correcting errors in said terrestrial magnetism heading sensor, comprising the steps of:

detecting a magnetized amount of said moving body on the basis of a heading of said moving body and a radius of a terrestrial magnetism heading circle, and

if said moving body curves, determining whether said moving body is located on a road represented in road map data, and in the case that said moving body is located on said road, detecting an amount of heading change of said moving body on the basis of a present location and a previous location of said moving body represented by said road map data, and in the case that said moving body is not located on said road, detecting the amount of heading change of said moving body on the basis of a rotational angle signal from a rotational angle sensor, and detecting a magnetized amount of said moving body on the basis of the detected amount of heading change when said moving body curves and two output signals from said terrestrial magnetism heading sensor before and after said moving body curves, and

correcting said heading signal on the basis of the detected magnetized amount.

11. A correcting method as set forth in claim 8, 9, or 10 which said moving body comprises a vehicle.