Travel path estimation apparatus and program

• US 8,948,455 B2
• Filed: 09/26/2011
• Issued: 02/03/2015
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Watanabe, Akihiro, Kojo, Takahiro, Limpibunterng, Theerawat, Tsuchiya, Yoshiaki
• Primary Examiner(s): GORADIA, SHEFALI DINESH
• Application Number:
  US13/820,030
• Publication Number:
  US 20130177211A1
• Time in Patent Office: 1,226 Days
• Field of Search: 382/103
• US Class Current: 382/103
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30244 Camera pose
• CPC Class Codes: G06T 2207/30256 Lane; Road marking
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06T 7/77 using statistical methods
• 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 characteristic point extraction section acquires an image captured by an image capture device and extracts characteristic points from the captured image, a vehicle lane boundary point selection section selects vehicle lane boundary points that indicate vehicle lanes from the extracted characteristic points, a distribution determination section determines the distribution of the vehicle lane boundary points, a system noise setting section sets each system noise based on the distribution of vehicle lane boundary points, and a travel path parameter estimation section stably predicts travel path parameters based on the vehicle lane boundary points, past estimation results, and the system noise that has been set.

Claims

1. A travel path estimation apparatus comprising:

an acquisition section for acquiring a captured image of a periphery of a vehicle;

an extraction section for extracting, from the captured image acquired by the acquisition section, characteristic points indicating vehicle lanes;

a setting section for, based on a distribution of the characteristic points extracted by the extraction section, setting system noise expressing variation of travel path parameters when estimating travel path parameters related to a position or an angle of the vehicle itself with respect to a travel path for travel by the vehicle itself and related to a shape or a size of the travel path; and

an estimation section for estimating the travel path parameters by probability signal processing using a discrete time signal based on the characteristic points extracted by the extraction section, a previous estimation result of the travel path parameters, and the system noise set by the setting section.

2. The travel path estimation apparatus of claim 1, wherein the travel path parameters related to the position and the angle of the vehicle itself with respect to the travel path include a lateral position of the vehicle itself with respect to the travel path, a yaw angle with respect to a central line of the travel path and a pitch angle with respect to a plane of the travel path, and wherein the travel path parameters related to the shape and size of the travel path include a radius of curvature of the travel path and a vehicle lane width of the travel path.

3. The travel path estimation apparatus of claim 2, wherein:

when the characteristic points are only distributed in a far region on the captured image, the setting section lowers system noise corresponding to the radius of curvature of the travel path, the vehicle lane width of the travel path, and the lateral position of the vehicle itself with respect to the travel path;

when the characteristic points are only distributed in a near region on the captured image, the setting section lowers the system noise corresponding to the radius of curvature of the travel path;

when the characteristic points are in a distribution only expressing a vehicle lane left hand side boundary or only expressing a vehicle lane right hand side boundary, the setting section lowers the system noise corresponding to the vehicle lane width of the travel path and the pitch angle with respect to the plane of the travel path; and

when the number of characteristic points present is the same as or less than a predetermined specific number, the setting section lowers the system noise corresponding to all of the travel path parameters.

4. A non-transitory recording medium storing a travel path estimation program that causes a computer to function as each of the sections configuring the travel path estimation apparatus of claim 2.

5. A non-transitory recording medium storing a travel path estimation program that causes a computer to perform the functions of:

an acquisition section for acquiring a captured image of a periphery of a vehicle;

an extraction section for extracting, from the captured image acquired by the acquisition section, characteristic points indicating vehicle lanes;

a setting section for, based on a distribution of the characteristic points extracted by the extraction section, setting system noise expressing variation of travel path parameters when estimating travel path parameters related to a position or an angle of the vehicle itself with respect to a travel path for travel by the vehicle itself and related to a shape or a size of the travel path; and

an estimation section for estimating the travel path parameters by probability signal processing using a discrete time signal based on the characteristic points extracted by the extraction section, a previous estimation result of the travel path parameters, and the system noise set by the setting section.

6. A travel path estimation system, comprising:

a memory; and

a processor configured to;

acquire a captured image of a periphery of a vehicle;

extract, from the captured image characteristic points indicating vehicle lanes;

set system noise expressing variation of travel path parameters, based on a distribution of the extracted characteristic points, when estimating travel path parameters related to a position or an angle of the vehicle with respect to a travel path for travel by the vehicle and related to a shape or a size of the travel path; and

estimate the travel path parameters by probability signal processing using a discrete time signal based on the extracted characteristic points, a previous estimation result of the travel path parameters, and the set system noise.