Lane recognition apparatus

• US 20060210116A1
• Filed: 03/16/2006
• Published: 09/21/2006
• Est. Priority Date: 03/18/2005
• Status: Active Grant

• Current Assignee: Honda Elesys Co., Ltd. (Nidec Corporation)
• Original Assignee: Honda Elesys Co., Ltd. (Nidec Corporation)
• Inventors: Azuma, Takahiro
• Granted Patent: US 7,889,887 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: G06V 10/48 by mapping characteristic values of the pattern into a parameter space, e.g. Hough transformation
• 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 lane recognition apparatus that recognizes a lane from an input image sequence captured from a visual sensor mounted on a vehicle at a fixed time interval, includes a time series smoothing part for generating a smoothed feature image based on a feature image extracted from the input image sequence so that a dotted line lane boundary describes a linear locus over time, a gradient image generation part for generating a gradient image by estimating a feature value gradient at each pixel position of the smoothed feature image, and a Hough transform part for performing Hough transform on the gradient image and detecting lines of edges in the smoothed feature image.

Claims

1. A lane recognition apparatus that recognizes a lane from an input image sequence captured from a visual sensor mounted on a vehicle at a fixed time interval, comprising:

a time series smoothing part for generating a smoothed feature image based on a feature image extracted from the input image sequence so that a dotted line lane boundary describes a linear locus over time;

a gradient image generation part for generating a gradient image by estimating a feature value gradient at each pixel position of the smoothed feature image; and

a Hough transform part for performing Hough transform on the gradient image and detecting lines of edges in the smoothed feature image.

2. A lane recognition apparatus according to claim 1, further comprising

an inverse perspective projection part for projecting each image of the input image sequence on a plane coordinate system that approximates a road surface in accordance with an optical model of a sensor and supplying a projection image of the road surface to the time series smoothing part.

3. A lane recognition apparatus according to claim 2, further comprising

a feature image extraction part for extracting the feature image indicating the likelihood of the lane boundary by a feature value based on peripheral pixels at each pixel position of the projection image of the road surface and supplying the feature image to the time series smoothing part.

4. A lane recognition apparatus according to claim 1, wherein

the time series smoothing part adds the feature image at a certain time into the smoothed feature image at the preceding time at a predetermined rate for updating the smoothed feature image to obtain a smoothed feature image smoothed in time series.

5. A lane recognition apparatus according to claim 4, wherein

the time series smoothing part further adds a predetermined arithmetic formula having spatial frequency response to the smoothed feature image in order to emphasize a dotted line lane boundary that describes a linear locus over time.