Current position sensing system, map display system and current position sensing method

• US 20070208507A1
• Filed: 02/22/2007
• Published: 09/06/2007
• Est. Priority Date: 03/03/2006
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Gotoh, Masayuki
• Application Number:
  US11/709,273
• Publication Number:
  US 20070208507A1
• Time in Patent Office: Days
• US Class Current: 701/210
• CPC Class Codes: G01C 21/30 Map- or contour-matching

Abstract

When information of a target, with which position information is associated, is extracted from map information, a relative position of a measurement subject, which is sensed by a radar, is obtained. Next, an absolute position of the measurement subject is estimated based on a current position of a vehicle, which is sensed through a GPS receiver, and a relative position of the measurement subject. When a distance between the measurement subject and the target is less than a predetermined threshold value, the measurement subject, which is sensed by the radar, is recognized as the target. An absolute position of the vehicle is computed based on the position information of the target and the relative position of the target. The position of the vehicle, which is sensed by the GPS receiver, is corrected to the computed absolute position.

Claims

1. A current position sensing system for sensing a current position of a movable entity, comprising:

a current position sensing means for sensing an approximate current position of the movable entity;

a map information storing means for storing map information that includes information of a target, with which position information that indicates a latitude and a longitude of the target is associated;

a relative position sensing means for sensing a relative position of a measurement subject with respect to the movable entity;

a target extracting means for extracting the information of the target from the map information when the target is located within a predetermined sensing range where the measurement subject is sensible by the relative position sensing means at a time of operating the relative position sensing means at the current position sensed by the current position sensing means;

an obtaining means for obtaining the relative position of the measurement subject, which is sensed by the relative position sensing means when the information of the target is extracted by the target extracting means;

an estimating means for estimating an absolute position of the measurement subject based on the current position of the movable entity, which is sensed by the current position sensing means, and the relative position of the measurement subject, which is obtained by the obtaining means;

a recognizing means for recognizing the measurement subject, which is sensed by the relative position sensing means, as the target, which is extracted by the target extracting means, when a distance between the measurement subject, the absolute position of which is estimated by the estimating means, and the target, which is extracted by the target extracting means, is less than a predetermined threshold value; and

a correcting means for correcting the current position of the movable entity, which is sensed by the current position sensing means, to an absolute position of the movable entity, wherein the absolute position of the movable entity is computed based on the position information of the target, which is recognized by the recognizing means, and the relative position of the target, which is obtained by the obtaining means.

2. The current position sensing system according to claim 1, further comprising:

a correction amount computing means for computing a correction amount of the current position of the movable entity, which is used by the correcting means to correct the current position of the movable entity; and

a first storing means for storing the correction amount, which is computed by the correction amount computing means, in a correction amount data storing means as correction amount data.

3. The current position sensing system according to claim 1, further comprising:

an image capturing means for capturing an image around the movable entity;

an imaging subject sensing means for sensing a type of an imaging subject, which is included in the image captured by the image capturing means, and a relative position of the imaging subject with respect to the movable entity by processing the image;

a position determining means for determining an absolute position of the imaging subject based on the corrected current position of the movable entity, which is corrected by the correcting means, and the relative position of the imaging subject, which is sensed by the imaging subject sensing means;

a stored information identifying means for determining whether information of the imaging subject, the absolute position of which is determined by the position determining means, is stored in the map information storing means; and

a second storing means for storing an erroneous difference between the absolute position of the imaging subject, which is determined by the position determining means, and the position of the imaging subject, which is stored in the map information storing means, in an error data storing means as error data when the stored information identifying means determines that the information of the imaging subject is stored in the map information storing means.

4. The current position sensing system according to claim 3, further comprising a third storing means for storing the type of the imaging subject, which is sensed by the imaging subject sensing means, and the absolute position of the imaging subject, which is determined by the position determining means, in a new data storing means when the stored information identifying means determines that the information of the imaging subject is not stored in the map information storing means.

5. The current position sensing system according to claim 2, further comprising a data transmitting means for externally transmitting the data, which is stored in the storing means.

6. A map display system comprising:

the current position sensing system recited in claim 1; and

a display device that displays a map, which corresponds to the current position of the movable entity that is sensed by the current position sensing system.

7. A current position sensing method for sensing a current position of a movable entity upon execution of the current position sensing method in a current position sensing system, which includes:

a current position sensing means for sensing an approximate current position of the movable entity;

a map information storing means for storing map information that includes information of a target, with which position information that indicates a latitude and a longitude of the target is associated; and

a relative position sensing means for sensing a relative position of a measurement subject with respect to the movable entity, the current position sensing method comprising;

extracting the information of the target from the map information when the target is located within a predetermined sensing range where the measurement subject is sensible by the relative position sensing means at a time of operating the relative position sensing means at the current position sensed by the current position sensing means;

obtaining the relative position of the measurement subject, which is sensed by the relative position sensing means when the information of the target is extracted through the extracting of the information of the target;

estimating an absolute position of the measurement subject based on the current position of the movable entity, which is sensed by the current position sensing means, and the relative position of the measurement subject, which is obtained through the obtaining of the relative position of the measurement subject;

recognizing the measurement subject, which is sensed by the relative position sensing means, as the target, which is extracted through the extracting of the information of the target, when a distance between the measurement subject, the absolute position of which is estimated through the estimating of the absolute position of the measurement subject, and the target, which is extracted through the extracting of the information of the target, is less than a predetermined threshold value; and

correcting the current position of the movable entity, which is sensed by the current position sensing means, to an absolute position of the movable entity, wherein the absolute position of the movable entity is computed based on the position information of the target, which is recognized through the recognizing of the measurement subject, and the relative position of the target, which is obtained through the obtaining of the relative position of the measurement subject.