Estimation device, estimation method and estimation program for position of mobile unit

• US 8,204,643 B2
• Filed: 02/28/2007
• Issued: 06/19/2012
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Nakano, Tsuyoshi
• Primary Examiner(s): Elchanti, Hussein
• Assistant Examiner(s): Khatib, Rami
• Application Number:
  US12/295,088
• Publication Number:
  US 20090248305A1
• Time in Patent Office: 1,938 Days
• Field of Search: 701/207, 701/208, 701/217, 701/300, 701/23, 701/28, 701/408, 701/409, 701/445, 701/446, 701/448, 701/461, 701/469, 701/472, 701/494, 701/495, 701/500, 701/501, 701/519, 701/520, 701/523, 701/532, 701/534, 340/990, 3409951-99528, 382/104, 382/106, 382/153, 348113-120, 700/245, 700/253, 700/259
• US Class Current: 701/28
• 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 estimating a position of a mobile unit, comprising:

a wide-angle camera configured to generate a wide-angle camera image;

a storage configured to store a map of a landmark including a break formed at an intersection between a floor and an object on the floor, said object is perpendicular to the floor;

a landmark matching unit configured to match a landmark found from the wide-angle camera image against the landmark on the map to estimate a self-position of the mobile unit;

a break projecting unit configured to obtain at least a first projected break projected onto the wide-angle camera image based on the break stored in the storage and on the self-position of the mobile unit estimated by the landmark matching unit; and

a break matching unit configured to match at least the first projected break and a break in the wide-angle camera image,

wherein when the break in the wide-angle camera image corresponding to said first projected break is absent, said break matching unit configured to evaluate an error between said first projected break and a second projected break projected by said break projecting unit on to the wide-angle camera image based on the break stored in the storage and another estimated self-position of the mobile unit estimated by an internal sensor of the mobile unit.

2. An estimation method for estimating a position of a mobile unit, comprising:

generating a wide-angle camera image;

storing a map of a landmark including a break formed at an intersection between a floor and an object on the floor, said object is perpendicular to the floor;

matching, using a position estimating unit, a landmark found from the wide-angle camera image against the landmark on the map to estimate a self-position of the mobile unit;

obtaining at least a first projected break projected based on the stored break and on the self-position of the mobile unit estimated by the matching onto the wide-angle camera image; and

matching, using the position estimating unit, at least the first projected break and a break in the wide-angle camera image,

wherein when the break in the wide-angle camera image corresponding to said first projected break is absent, evaluating an error between said first projected break and a second projected break projected on to the wide-angle camera image based on the stored break and another estimated self-position of the mobile unit estimated by an internal sensor of the mobile unit.

3. A mobile robot with a storage medium having stored thereon an estimation program for estimating a position of the mobile robot, the estimation program causing said mobile robot to execute the following steps:

generating a wide-angle camera image;

storing a map of a landmark including a break formed at an intersection between a floor and an object on the floor, said object is perpendicular to the floor;

matching a landmark found from the wide-angle camera image against the landmark on the map to estimate a self-position of the mobile robot;

obtaining at least a first projected break projected based on the stored break and on the self-position of the mobile robot estimated by the matching onto the wide-angle camera image; and

matching at least the first projected break and a break in the wide-angle camera image,

wherein when the break in the wide-angle camera image corresponding to said first projected break is absent, evaluating an error between said first projected break and a second projected break projected on to the wide-angle camera image based on the stored break and another estimated self-position of the mobile unit estimated by an internal sensor of the mobile unit.