US 5,347,588 AGranted

Method and apparatus for video imaging of tire ground contact patch

AssigneeBridgestone Corporation

InventorPaul B. Wilson

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Abstract

A method and apparatus for video imaging of a tire ground contact patch or tire footprint is presented. A digitized image of the footprint is generated as an array of pixels. Each pixel is attributed a binary value of one or zero, to present a two-valued image. Contact areas within the image are attributed a first value, while void or noncontact areas are attributed a second value. The image is then dilated and eroded in an appropriate sequence to eliminate all white pixels from the image and to eliminate surface anomalies or the like which are not of interest in the tire analysis. An image of the footprint, accurate in size and dimensions, is thereby generated and, from such footprint, total area, contact area, and void area can be determined, as well as measurements of width, center line length, and other desired lengths at various lateral width locations. This data may be used to analyze the tire construction, operation, noise generation, and performance.

Claims11

Dependent claims

Apparatus for video imaging the interface area between a tire and its contacting loading surface, also known as a tire footprint, comprising:

first means for generating a tire footprint upon a surface;
second means for generating a digitized video image of said footprint from said surface, said digitized video image comprising an array of pixels and having contact regions corresponding to tire tread elements, and void regions corresponding to regions between the tread elements;
third means for receiving said digitized video image and determining the area of said contact regions within said footprint image;
and
fourth means for receiving said digitized video image and determining the area and boundary contour of said footprint image, said fourth means comprising a dilation filter, and an erosion filter, said dilation filter filtering said digitized video image a first number of times until all pixels within a region encompassed by the contour of the footprint are of a same value and said video image is a dilated image, said erosion filter receiving said dilated image and filtering said dilated image said first number of times plus an additional time, generating an eroded image, said dilation filter subsequently filtering said eroded image one additional time, generating a uniform footprint image wherein all pixels comprising the uniform footprint image are at equal value.

2 more elements

Dependencies are inferred from the claim text.