ESTIMATION DEVICE, ESTIMATION METHOD AND ESTIMATION PROGRAM FOR POSITION OF MOBILE UNIT

• US 20090248305A1
• Filed: 02/28/2007
• Published: 10/01/2009
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Nakano, Tsuyoshi
• Granted Patent: US 8,204,643 B2
• Time in Patent Office: Days
• US Class Current: 701/223
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

Enabled is to estimate a self-position even when no landmark is seen or when an article confusing the landmark is brought in. An omnidirectional camera recognizes a vertical land-mark near a wall to determine a candidate for the self-position. On the basis of the candidate determined, a break in a map between a floor and a wall is projected on the camera image thereby to perform the matching.

Claims

1. An estimation device for a position of a mobile unit, comprising a wide-angle camera and a map of a landmark, which checks a landmark found from a wide-angle camera image against a landmark on the map to estimate a self-position of the mobile unit, the device characterized in that:

a break between a floor and an object that is perpendicular to the floor is stored in said map; and

in order to evaluate validity of the estimated self-position, matching means for evaluating an error between a break obtained by projecting the break stored in the map onto the wide-angle camera image based on the estimated self-position and a break in the wide-angle camera image is provided.

2. The estimation device for a position of a mobile unit according to claim 1, characterized in that in said matching means, when the break in the wide-angle camera image corresponding to said break obtained by projecting is absent, an error between a break obtained by projecting onto the wide-angle camera image the break stored in the map based on a self-position found in an internal sensor of the mobile unit and the break projected based on said estimated self-position is evaluated.

3. An estimation method for a position of a mobile unit in which a wide-angle camera and a map of a landmark are used, and a landmark found from a wide-angle camera image is checked against a landmark on the map to estimate a self-position of the mobile unit, the method characterized in that:

a break between a floor and an object that is perpendicular to the floor is stored in said map; and

in order to evaluate validity of the estimated self-position, an error between a break obtained by projecting the break stored in the map onto the wide-angle camera image based on the estimated self-position and a break in the wide-angle camera image is estimated.

4. The estimation method for a position of a mobile unit according to claim 3, characterized in that when the break in the wide-angle camera image corresponding to said break obtained by projecting is absent, an error between a break obtained by projecting, onto the wide-angle camera image, the break stored in the map based on a self-position found in an internal sensor of the mobile unit, and the break projected based on said estimated self-position is evaluated.

5. An estimation program for a position of a mobile unit for estimating a self-position of the mobile unit by referring to an image from a wide-angle camera and a map of a landmark and checking a landmark found from the wide-angle camera image against the landmark on the map, the program characterized by being provided with:

an order for extracting the landmark from the wide-angle camera image and check the same against the landmark on the map to thereby estimate the self-position of the mobile unit;

an order for reading out a break between a floor and an object that is perpendicular to the floor, which is stored in said map; and

a matching order for evaluating an error between a break obtained by projecting the break stored in the map onto the wide-angle camera image based on the estimated self-position and a break in the wide-angle camera image in order for evaluating validity of the estimated self-position are provided.

6. The estimation program for a position of a mobile unit according to claim 5, characterized in that in said matching order, when the break in the wide-angle camera image corresponding to said break obtained by projecting is absent, an error between a break obtained by projecting onto the wide-angle camera image the break stored in the map based on a self-position found in an internal sensor of the mobile unit and the break projected based on said estimated self-position is evaluated.