Self-Position Calculating Apparatus and Self-Position Calculating Method

• US 20170011268A1
• Filed: 02/24/2014
• Published: 01/12/2017
• Est. Priority Date: 02/24/2014
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yamaguchi, Ichiro, Nishiuchi, Hidekazu
• Granted Patent: US 10,043,080 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60Q 1/085 due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers B60Q1/10, B60Q1/12, B60Q1/1423 take precedence
• CPC Class Codes: B60Q 2400/50 Projected symbol or information, e.g. onto the road or car body
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 21/265 constructional aspects of navigation devices, e.g. housings, mountings, displays G01C21/3688 takes precedence
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• 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-position calculating apparatus includes: a light projector 11 configured to project a patterned light beam 32a onto a road surface 31 around a vehicle; and a camera 12 configured to capture an image 38 of the road surface 31 around the vehicle including an area onto which the patterned light beam 32a is projected. The self-position calculating apparatus calculates an orientation angle of the vehicle 10 relative to the road surface 31 from a position of the patterned light beam 32a on the image 38 obtained by the camera 12, and calculates an amount of change in the orientation of the vehicle based on temporal changes in multiple feature points on the road surface which are detected from the image 38. The self-position calculating apparatus calculates current position and orientation angle of the vehicle by adding the amount of change in the orientation to initial position and orientation angle of the vehicle. If a condition under which the multiple feature points are detected does not satisfy a first criterion, the self-position calculating apparatus projects the patterned light beam 32a.

Claims

1. A self-position calculating apparatus comprising:

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

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

an orientation angle calculator configured to calculate an orientation angle of the vehicle relative to the road surface from a position of the patterned light beam on the image obtained by the camera;

an orientation change amount calculator configured to calculate an amount of change in the orientation of the vehicle based on temporal changes in a plurality of feature points on the road surface which are detected from the image obtained by the camera;

a self-position calculator configured to calculate current position and orientation angle of the vehicle by adding the amount of change in the orientation to initial position and orientation angle of the vehicle;

a detection condition determining circuit configured to determine under what condition the plurality of feature points are detected by the orientation change amount calculator; and

a patterned light beam controller configured to control how the light projector projects the patterned light beam, wherein

if the detection condition determining circuit determines that the condition under which the plurality of feature points are detected does not satisfy a first criterion, the patterned light beam controller projects the patterned light beam.

2. The self-position calculating apparatus according to claim 1, wherein if the detection condition determining circuit determines that the condition under which the plurality of feature points are detected satisfies the first criterion, the patterned light beam controller stops projecting the patterned light beam.

3. The self-position calculating apparatus according to claim 1, wherein if the detection condition determining circuit determines that the condition under which the plurality of feature points are detected does not satisfy a second criterion lower than the first criterion, the orientation angle calculator calculates the orientation angle of the vehicle relative to the road surface from the position of the patterned light beam.

4. The self-position calculating apparatus according to claim 1, wherein after a first predetermined length of time elapses from when the patterned light beam controller starts to project the patterned light beam, the orientation angle calculator starts to calculate the orientation angle of the vehicle relative to the road surface from the position of the patterned light beam.

5. The self-position calculating apparatus according to claim 1, wherein if the detection condition determining circuit determines that the condition under which the plurality of feature points are detected does not satisfy the first criterion, the patterned light beam controller stops projecting the patterned light beam after a second predetermined length of time elapses from when the detection condition determining circuit makes the determination.

6. The self-position calculating apparatus according to claim 1, wherein if the detection condition determining circuit determines that the condition under which the plurality of feature points are detected does not satisfy the first criterion, the patterned light beam controller starts to project the patterned light beam after a third predetermined length of time elapses from when the detection condition determining circuit makes the determination.

7. A self-position calculating method comprising:

projecting a patterned light beam onto a road surface around a vehicle, by a light projector installed in the vehicle;

capturing an image of the road surface around the vehicle including an area onto which the patterned light beam is projected, by a camera installed in the vehicle;

calculating an orientation angle of the vehicle relative to the road surface from a position of the patterned light beam on the image, by a controller of the vehicle;

calculating an amount of change in the orientation of the vehicle based on temporal changes in a plurality of feature points on the road surface which are detected from the image, by the controller; and

calculating current position and orientation angle of the vehicle by adding the amount of change in the orientation to initial position and orientation angle of the vehicle, by the controller, wherein

the light projector projects the patterned light beam if the controller determines that a condition under which the plurality of feature points are detected does not satisfy a first criterion.