ROADSIDE OBJECT DETECTION APPARATUS

• US 20150165972A1
• Filed: 10/26/2012
• Published: 06/18/2015
• Est. Priority Date: 06/19/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Takemae, Yoshinao, Watanabe, Akihiro, Ichino, Fumiya
• Granted Patent: US 9,676,330 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 2552/25 Road altitude
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: G06T 2207/10021 Stereoscopic video; Stereoscopic image sequence
• CPC Class Codes: G06T 2207/20061 Hough transform
• CPC Class Codes: G06T 2207/30256 Lane; Road marking
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• 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
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A roadside object detection apparatus to detect a roadside object using a plurality of captured images includes a height information detection unit configured to analyze the captured images, and to detect height information of an object in the captured images in a neighboring region having a distance less than or equal to a threshold from a vehicle having the roadside object detection apparatus installed; a height change detection unit configured to detect a change of a height of a road surface due to the roadside object from the height information in the neighboring region; a characteristic point extrapolation unit configured to determine positions having the change of the height detected as characteristic points of the roadside object, and to extrapolate the characteristic points into a far-off region having a distance greater than or equal to the threshold from the vehicle, based on a road model; and a roadside object detection unit configured to set a search range for the roadside object in the far-off region based on a virtual line that is obtained by the characteristic points being extrapolated by the characteristic point extrapolation unit, and to detect the roadside object in the far-off region based on the search range.

Claims

1. A roadside object detection apparatus to detect a roadside object using a plurality of captured images, comprising:

a height information detection unit configured to analyze the captured images, and to detect height information of an object in the captured images in a neighboring region having a distance less than or equal to a threshold from a vehicle having the roadside object detection apparatus installed;

a height change detection unit configured to detect a change of a height of a road surface due to the roadside object from the height information in the neighboring region;

an extrapolation unit configured to determine positions having the change of the height detected as characteristic points of the roadside object, to define a road model based on the characteristic points, and to extrapolate the road model into a far-off region having a distance greater than or equal to the threshold from the vehicle; and

a roadside object detection unit configured to set a search range for the roadside object in the far-off region based on a virtual line that is obtained by the road model being extrapolated by the extrapolation unit, and to detect the roadside object in the far-off region based on the search range.

2. The roadside object detection apparatus as claimed in claim 1, wherein the roadside object detection unit includes

a search range setting unit configured to set the search range for the roadside object by translating the virtual line by predetermined distances to opposite directions in a symmetric or non-symmetric manner with respect to the virtual line, and

a line segment identification unit configured to detect edges in the search range, to generate one or more line segments from the edges, and to identify the line segments originated from the characteristic points of the roadside object in the far-off region based on at least one of the number of the line segments, and lengths of the line segments.

3. The roadside object detection apparatus as claimed in claim 1, wherein the roadside object detection unit includes

a search range setting unit configured to set the search range for the roadside object by translating the virtual line by predetermined distances to opposite directions in a symmetric or non-symmetric manner with respect to the virtual line, and

a template matching unit configured to detect the roadside object in the far-off region by applying template matching to the search range with a template image for the neighboring region, the template image being cut off from the captured images and including the roadside object in the neighboring region.

4. The roadside object detection apparatus as claimed in claim 1, further comprising:

a lane separation mark detection unit configured to detect, based on at least one of the captured images, a lane separation mark that defines a lane in which the vehicle travels,

wherein the roadside object detection unit includes

a search range setting unit configured to set the search range for the roadside object by translating the virtual line in a direction such that the translated virtual line is positioned between the virtual line and the lane separation mark that is closer to the vehicle among the lane separation marks on left and right with respect to a traveling direction, and by translating the virtual line by a predetermined distance in an opposite direction,

a line segment identification unit configured to detect edges in the search range, to generate one or more line segments from the edges, and to identify the line segment generated from the characteristic points of the roadside object in the far-off region based on at least one of the number of the line segments, and lengths of the line segments.

5. The roadside object detection apparatus as claimed in claim 1, further comprising:

a preceding vehicle detection unit configured to detect a preceding vehicle with at least a lateral position of the preceding vehicle,

wherein the roadside object detection unit includes

a search range setting unit configured to set the search range for the roadside object by translating the virtual line in a direction such that the translated virtual line is positioned between the virtual line and the preceding vehicle, and by translating the virtual line by a predetermined distance in an opposite direction,

a line segment identification unit configured to detect edges in the search range, to generate one or more line segments from the edges, and to identify the line segment generated from the characteristic points of the roadside object in the far-off region based on at least one of the number of the line segments, and lengths of the line segments.

6. The roadside object detection apparatus as claimed in claim 3, wherein the template matching unit executes the template matching starting from a region closer to the vehicle in the search range, and when detecting the roadside object in the far-off region with the template image for the neighboring region, newly sets a region including the detected roadside object as a template image to execute the template matching for a next close region to the vehicle in the search range.

7. The roadside object detection apparatus as claimed in claim 2, wherein the line segment identification unit estimates an existence of a sidewalk step if the number of the line segments generated from the characteristic points of the roadside object in the far-off region is two, and estimates an existence of a curbstone if the number of the line segments is three.

8. The roadside object detection apparatus as claimed in claim 4, wherein the line segment identification unit estimates an existence of a sidewalk step if the number of the line segments generated from the characteristic points of the roadside object in the far-off region is two, and estimates an existence of a curbstone if the number of the line segments is three.

9. The roadside object detection apparatus as claimed in claim 5, wherein the line segment identification unit estimates an existence of a sidewalk step if the number of the line segments generated from the characteristic points of the roadside object in the far-off region is two, and estimates an existence of a curbstone if the number of the line segments is three.