Traffic line recognition device

• US 20050196019A1
• Filed: 08/06/2004
• Published: 09/08/2005
• Est. Priority Date: 03/08/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Manabu, Taniguchi, Hiroyasu
• Granted Patent: US 7,346,190 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• 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 traffic line recognition device includes: a traffic line region candidate extraction section that extracts a traffic line candidate, as a traffic line candidate, from a road image obtained by a TV camera installed on a vehicle; a two dimension/three dimension transform section that transforms two dimensional image coordinates of a pixel contained in the traffic line region candidate into three dimensional coordinates; a histogram production section that accumulates and projects the three dimensional coordinates onto a coordinate system in a direction crossing a road and produces a histogram in the direction crossing the road; and a traffic line judgement unit determines a traffic line based on that histogram.

Claims

1. A traffic line recognition device comprising:

a traffic line region candidate extraction section for extracting a traffic line region candidate, as a traffic line candidate, from a road image obtained by a TV camera installed on a vehicle;

a two dimension/three dimension transform section for transforming two dimensional image coordinates of a pixel contained in the traffic line region candidate to three dimensional coordinates;

a histogram production section for accumulating and projecting the three dimensional coordinates onto a coordinate system in a direction crossing a road and producing a histogram in the direction crossing the road; and

a traffic line judgement unit for determining a traffic line based on a value of the histogram.

2. The traffic line recognition device as claimed in claim 1, wherein the traffic line judgement unit includes:

a local maximum value position extraction section for finding a position of a local maximum value in the histogram in the direction crossing the road;

and a traffic line information extraction block for extracting a traffic line region candidate having an intersection as traffic line information based on presence or absence of an intersection of (i) a traffic line candidate acquired by transforming a straight line corresponding to the position of the local maximum value and extending parallel to the road into image coordinates, and (ii) a traffic line region candidate for each scanning line in the direction crossing the road in an image.

3. The traffic line recognition device as claimed in claim 2, wherein the traffic line information extraction block extracts at least one item of information from among:

the number of occurrences in the histogram corresponding to the traffic line candidate;

traffic line width, traffic line position, and angle of traffic line, based on the traffic line region candidate having an intersection; and

distance between traffic lines and a center position between traffic lines when pairing two traffic line candidates, as traffic line information.

4. The traffic line recognition device as claimed in claim 3, wherein the traffic line judgement unit includes a rate of reliability calculation section for calculating rate of comformability of traffic line information acquired by the traffic line information extraction block with one of (i) information for a traffic line acquired by the last traffic line recognition processing and (ii) a previously set model value, and for calculating the rate of reliability of the traffic line by weighting the rate of comformability.