Self-location calculating device and self-location calculating method

• US 9,721,170 B2
• Filed: 02/24/2014
• Issued: 08/01/2017
• Est. Priority Date: 02/24/2014
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Nishiuchi, Hidekazu, Yamaguchi, Ichiro
• Primary Examiner(s): TRUONG, NGUYEN T
• Application Number:
  US15/119,161
• Publication Number:
  US 20170024617A1
• Time in Patent Office: 1,254 Days
• Field of Search: 348148
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G06T 2207/30244 Camera pose
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

A self-location calculating device projects a patterned light onto a road surface around a vehicle, captures and obtains an image of the road surface around the vehicle. When determining that a condition of the road surface around the vehicle changes as much as or more than a threshold value, the self-location calculating device calculates a current position and a current attitude angle of the vehicle in present by adding an amount of change in the attitude to a current position and a current attitude angle of the vehicle which are calculated in a previous information process cycle.

Claims

1. A self-location calculating device comprising:

a light projector configured to project a patterned light onto a road surface around a vehicle;

an image capturing unit installed in the vehicle, and configured to capture and obtain an image of the road surface around the vehicle including an area onto which the patterned light is projected;

an attitude angle calculation unit configured to calculate an attitude angle of the vehicle relative to the road surface from a position of the patterned light on the image obtained by the image capturing unit;

an attitude change amount calculation unit configured to calculate an amount of change in the attitude of the vehicle based on temporal changes in a plurality of feature points on the road surface on the image obtained by the image capturing unit;

a self-location calculation unit configured to calculate a current position and a current attitude angle of the vehicle by adding the amount of change in the attitude to an initial position and the attitude angle of the vehicle; and

a road surface condition determination unit configured to determine whether or not a condition of the road surface around the vehicle changes as much as or more than a threshold value by detecting a change in the condition of the road surface, wherein

when the road surface condition determination unit determines that the condition of the road surface changes as much as or more than the threshold value, the self-location calculation unit calculates the current position and the current attitude angle of the vehicle by adding the amount of change in the attitude to the current position and the current attitude angle of the vehicle which are calculated in a previous information process cycle.

2. The self-location calculating device according to claim 1, wherein the road surface condition determination unit estimates the change in the condition of the road surface from an amount of change in a height of the road surface.

3. The self-location calculating device according to claim 2, wherein the road surface condition determination unit estimates the amount of change in the height of the road surface from the position of the patterned light.

4. A self-location calculating method comprising:

a procedure of projecting a patterned light onto a road surface around a vehicle from a light projector installed in the vehicle;

a procedure of capturing and obtaining an image of the road surface around the vehicle including an area onto which the patterned light is projected, by an image capturing unit installed in the vehicle;

a procedure of calculating an attitude angle of the vehicle relative to the road surface from a position of the patterned light on the image in a control unit of the vehicle;

a procedure of calculating an amount of change in the attitude of the vehicle based on temporal changes in a plurality of feature points on the road surface on the image in the control unit;

a self-location calculating procedure of calculating a current position and a current attitude angle of the vehicle by adding the amount of change in the attitude to an initial position and the attitude angle of the vehicle in the control unit; and

a road surface condition determining procedure of determining whether or not a condition of the road surface around the vehicle changes as much as or more than a threshold value by detecting a change in the condition of the road surface in the control unit, wherein

when in the road surface condition determining procedure, it is determined that the condition of the road surface changes as much as or more than the threshold value, the current position and the current attitude angle of the vehicle are calculated in the self-location calculating procedure by adding the amount of change in the attitude to the current position and the current attitude angle of the vehicle which are calculated in a previous information process cycle.