Movement detecting device

• US 5,828,987 A
• Filed: 04/22/1997
• Issued: 10/27/1998
• Est. Priority Date: 08/28/1995
• Status: Expired due to Term

• Current Assignee: Data Tec Company Limited
• Original Assignee: Data Tec Company Limited
• Inventors: Miyasaka, Tsutomu, Tano, Michiyasu
• Primary Examiner(s): SHAH, KAMINI S
• Application Number:
  US08/809,459
• Time in Patent Office: 553 Days
• Field of Search: 364/566, 364/449.7, 364/443, 364/454, 701/216, 701/215, 701/213, 340/988, 340/990, 342/451, 342/457, 342/357
• US Class Current: 702/150
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01D 5/04 using levers; using cams; using gearing
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/2451 Incremental encoders G01D5/2454 takes precedence
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/52 Determining velocity
• CPC Class Codes: G01S 19/53 Determining attitude

Abstract

A movement detecting device capable of accurately measuring the position, the speed and the azimuth of a moving object, such as a vehicle, by using GPS signals without applying a particular alteration to the moving object, is purposed. For realizing it, in an arithmetic control section 3, especially in a speed arithmetic processing section 41, an azimuth arithmetic processing section 42 and a position arithmetic processing section 43, data about relationship between the absolute speed, etc. based on the GPS signals and the relative speed, etc. based on an inertia sensor 5 are derived when the GPS signals are normally received, and data about the actual speed and azimuth of the moving object are derived using the foregoing data about the relationship and the relative speed, etc. when the GPS signals are not received.

Claims

1. A movement detecting device comprising:

GPS arithmetic means for producing first movement data based on GPS signals, said first movement data including variation components of an absolute position, an absolute speed and an absolute azimuth of a moving object;

an inertia sensor for detecting an acceleration generated in a traveling direction of the moving object and an angular velocity generated about an axis having a fixed inclination relative to the traveling direction;

means for producing second movement data from the acceleration and the angular velocity measured by said inertia sensor, said second movement data including variation components of a relative position, a relative speed and a relative azimuth of the moving object; and

arithmetic control means for correcting said first and second movement data based on the mutual data and producing actual movement data including an actual position, an actual speed and an actual azimuth of the moving object through calculation, wherein said arithmetic control means comprises a speed arithmetic processing section which comprises;

(1) means for deriving a first motion acceleration (EGX) from a variation of a combined speed obtained through a filter combination of said absolute speed (VGX) and said relative speed (VX), and means for deriving a first gravitational acceleration (α

) by subtracting the first motion acceleration (EGX) from acceleration data (AX);

(2) means for converting angular data (θ

) obtained by integrating angular velocity data (q) into a second gravitational acceleration (β

);

(3) means for converting a third gravitational acceleration (ax) obtained through a filter combination of the first and second gravitational accelerations (α

, β

) into a fourth gravitational acceleration (β

x) based on a reference inclination;

(4) means for deriving an error (ε

) between the first gravitational acceleration (α

) and the fourth gravitational acceleration (β

x); and

(5) means for correcting the second gravitational acceleration (β

) by said error (ε

), deriving a second motion acceleration (EXoff) by subtracting a gravitational acceleration after the correction from the acceleration data (AX), and deriving an actual speed (V) by integrating the second motion acceleration (EXoff).

2. The movement detecting device as set forth in claim 1, characterized in that the filter combination of said absolute speed (VGX) and said relative speed (VX) and the filter combination of said first and second gravitational accelerations (α

,β

) are each in the form of a combination of values after passing through two kinds of filters having different frequency bands.

6. The movement detecting device as set forth in claim 1, characterized in that said arithmetic control means comprises a position arithmetic processing section which comprises:

(1) means for deriving a moved distance (D) by integrating said actual speed (Vm), and deriving a latitude variation value and a longitude variation value based on said moved distance (D) and said actual azimuth (ψ

m); and

(2) means for producing the actual position (LOGn, LATn) by correcting the sequentially updated absolute position (LOG, LAT) during its non-updated term using said latitude variation value and said longitude variation value.

3. A movement detecting device comprising:

GPS arithmetic means for producing first movement data based on GPS signals, said first movement data including variation components of an absolute position, an absolute speed and an absolute azimuth of a moving object;

an inertia sensor for detecting an acceleration generated in a traveling direction of the moving object and an angular velocity generated about an axis having a fixed inclination relative to the traveling direction;

means for producing second movement data from the acceleration and the angular velocity measured by said inertia sensor, said second movement data including variation components of a relative position, a relative speed and a relative azimuth of the moving object; and

arithmetic control means for correcting said first and second movement data based on the mutual data and producing actual movement data including an actual position, an actual speed and an actual azimuth of the moving object through calculation, wherein said arithmetic control means comprises an azimuth arithmetic processing section which comprises;

(1) means for deriving a combined relative azimuth (ψ

) through a filter combination of a variation per unit time of said absolute azimuth (ψ

G) and said relative azimuth (ψ

I); and

(2) means for selectively outputting one of a first actual azimuth obtained by summing said combined relative azimuth (ψ

) derived based on the sequentially updated absolute azimuth (ψ

G) and relative azimuth (ψ

I) and said absolute azimuth (ψ

G), and a second actual azimuth obtained by summing said relative azimuth (ψ

I) and said first actual azimuth.

4. The movement detecting device as set forth in claim 3, characterized in that the filter combination of the variation per unit time of said absolute azimuth (ψ

G) and said relative azimuth (ψ

I) is in the form of a combination of values after passing through two kinds of filters having different frequency bands.

7. The movement detecting device as set forth in claim 3, characterized in that said arithmetic control means comprises a position arithmetic processing section which comprises:

(1) means for deriving a moved distance (D) by integrating said actual speed (Vm), and deriving a latitude variation value and a longitude variation value based on said moved distance (D) and said actual azimuth (ψ

m); and

(2) means for producing the actual position (LOGn, LATn) by correcting the sequentially updated absolute position (LOG, LAT) during its non-updated term using said latitude variation value and said longitude variation value.

5. A movement detecting device comprising:

GPS arithmetic means for producing first movement data based on GPS signals, said first movement data including variation components of an absolute position, an absolute speed and an absolute azimuth of a moving object;

an inertia sensor for detecting an acceleration generated in a traveling direction of the moving object and an angular velocity generated about an axis having a fixed inclination relative to the traveling direction;

means for producing second movement data from the acceleration and the angular velocity measured by said inertia sensor, said second movement data including variation components of a relative position, a relative speed and a relative azimuth of the moving object; and

arithmetic control means for correcting said first and second movement data based on the mutual data and producing actual movement data including an actual position, an actual speed and an actual azimuth of the moving object through calculation, wherein said arithmetic control means comprises a position arithmetic processing section which comprises;

(1) means for deriving a moved distance (D) by integrating said actual speed (Vm), and deriving a latitude variation value and a longitude variation value based on said moved distance (D) and said actual azimuth (ψ

m); and

(2) means for producing the actual position (LOGn, LATn) by correcting the sequentially updated absolute position (LOG, LAT) during its non-updated term using said latitude variation value and said longitude variation value.