RECORDING MEDIUM FOR STORING POSITION ESTIMATION PROGRAM, POSITION ESTIMATION DEVICE, AND POSITION ESTIMATION METHOD

• US 20120172053A1
• Filed: 12/14/2011
• Published: 07/05/2012
• Est. Priority Date: 12/29/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: FUKUTA, Shigeki, Sasaki, Kazuo, Nakagawa, Itaru
• Granted Patent: US 8,571,575 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence

Abstract

A computer executes processing of acquiring, by using a positioning unit to output error region information indicating an ellipse-shaped error region represented by a position acquired from positioning performed by receiving a signal from a plurality of transmitters and a measurement error of the position, a plurality of pieces of the error region information by performing the positioning a plurality of times, processing of extending the error region indicated by each piece of the acquired error region information in a major axis direction, and processing of estimating a position of a positioning target based on an intersect region at which the extended error regions intersect with one another.

Claims

1. A non-transitory computer-readable portable storage medium for storing a position estimation program that causes a computer to execute processing to estimate a position of a positioning target, wherein the position estimation program causes the computer to execute processing of:

acquiring a plurality of pieces of error region information acquired by positioning performed plural times, by using a positioning unit to output the error region information indicating an ellipse-shaped error region represented by a position acquired from positioning performed after receiving a signal from a plurality of transmitters and a measurement error of the position,

extending the error region indicated by each piece of the acquired error region information in a major axis direction, and

estimating the position of the positioning target based on an intersect region in which the extended error regions intersect with one another.

2. The non-transitory computer-readable portable storage medium of claim 1 causing the computer to execute processing,

in the estimating of the position of the positioning target, for performing statistical processing of a plurality of coordinates, each indicating a position of a target region that is the error region and the intersect region, and for outputting the coordinates acquired as a result of the statistical processing as an estimated position of the positioning target.

3. The non-transitory computer-readable portable storage medium of claim 1 wherein the position estimation program further causes the computer to execute processing of

extracting error region information with a proportion of a semi-major axis to a semi-minor axis of the error region being a first threshold or more from the acquired error region information, and

extending the error region of the extracted error region information in a major axis direction when the error region is to be extended.

4. The non-transitory computer-readable portable storage medium of claim 2 wherein the position estimation program further causes the computer to execute processing of

extracting an intersect region in which an area of the intersect region is equal to or smaller than a second threshold,

wherein the error region and the extracted intersect region are the target region in the statistical processing.

5. The non-transitory computer-readable portable storage medium of claim 2 wherein

in the statistical processing, a median point of a cluster of coordinates of median points of the target regions is calculated and the calculated median point is output as the estimated position.

6. The non-transitory computer-readable portable storage medium of claim 5, wherein

in the statistical processing, a heavier weight is added to the coordinates of median points of each of the target regions for the target regions with a smaller area, and a median point of a cluster of coordinates of median points of each of the weighted target regions is calculated.

7. The non-transitory computer-readable portable storage medium of claim 6, wherein

in the statistical processing, the median point of the cluster of coordinates of median points of each of the target regions is calculated by dividing a coordinate of a median point of each of the target regions by each area of the target regions and summing results of the dividing, and dividing the summing by a summation of inverses of areas of the target regions.

8. The non-transitory computer-readable portable storage medium of claim 6, wherein

in the statistical processing, when the target regions are the error region, weight is added by multiplying the area of the target regions by m (m:

any real number) and when the target regions are the intersect region, weight is added by multiplying the area of the target regions by n (n;

any real number), and the median point of a cluster of coordinates of median points of each of the target regions is calculated by dividing a summation of values of coordinates of median points of the target regions divided by an area of the weighted target, by a summation of inverses of areas of the weighted target regions.

9. The non-transitory computer-readable portable storage medium of claim 5 wherein

in the statistical processing, when the target regions are the intersect region, a heavier weight is added to the coordinates of median points of each of the target regions for the target regions with a smaller total value of distances between the intersect region and two error regions that are the basis of the intersect region, and the median point of a cluster of coordinates of median points of each of the target regions is calculated.

10. The non-transitory computer-readable portable storage medium of claim 2 wherein the position estimation program causes the computer to execute processing of

extracting, when the target regions are the intersect region, the intersect region with the total of distances between the intersect region and the two error regions that are the basis of the intersect region being a third threshold or smaller, and

wherein in the statistical processing, the error region and the extracted intersect region are assigned as the target region.

11. A position estimation device for estimating a position of a positioning target, comprising:

a positioning unit to perform positioning a plurality of times by receiving a signal from a plurality of transmitters and to generate error region information indicating an ellipse-shaped error region represented by a position acquired by the positioning and a measurement error of the position;

an extension processing unit to extend the error region indicated by the generated error region information in a major axis direction;

an intersect region acquisition unit to acquire an intersect region at which the extended error region intersects with another extended error region; and

an estimation unit to estimate the position of the positioning target based on the intersect region at which the extended error region intersects with another extended error region.

12. The position estimation device of claim 11, wherein

the estimation unit assigns the error region and the intersect region as a target region, performs statistical processing of a plurality of coordinates, each indicating a position of the target region, and outputs the coordinates acquired as a result of the statistical processing as an estimated position of the positioning target.

13. The position estimation device of claim 11, further comprising:

a first extraction unit to extract information error region information with a proportion of a semi-major axis to a semi-minor axis of the error region being a first threshold or more from the generated error region.

14. The position estimation device of claim 12, further comprising:

a second extraction unit to extract an intersect region with an area of the intersection area being a second threshold or smaller,

wherein the estimation unit assigns the error region and the extracted intersect region as the target region.

15. A position estimation method of estimating a position of a positioning target, wherein a computer:

acquires a plurality of pieces of error region information acquired from positioning performed plural times using a positioning unit to output the error region information indicating an ellipse-shaped error region represented by a position acquired from positioning performed by receiving a signal from a plurality of transmitters and a measurement error of the position;

extends the error region indicated by each piece of the acquired error region information in a major axis direction, and

estimates the position of the positioning target based on an intersect region in which the extended error regions intersect with one another.

16. A position estimation device for estimating a position of a positioning target, comprising:

a positioning unit to perform positioning by receiving a signal transmitted from a transmitter and to generate a position acquired by the positioning, degradation information of the position, and an angle of the degradation information in a major axis;

an intersect region acquisition unit to acquire a plurality of pieces of information on the position and the angle from the positioning unit and to acquire an intersect region at which a plurality of pieces of line information specified on the basis of the acquired plurality of pieces of information on the position and the angle intersect with one another; and

an estimation unit to estimate the position of the positioning target based on the intersect region acquired in the intersect region acquisition unit.