Method for tire shoulder tread wear evaluation

A method for identifying worn tread shoulder regions on a tire having a tread surface extending circumferentially about an axis and extending axially between a pair of radially projected sidewall surfaces, comprising:

• acquiring a plurality of measurements representative of tread depth within a shoulder region of interest extending both axially and circumferentially over at least a portion of said tire tread surface adjacent to one of said radially projected sidewall surfaces;
• identifying, from said plurality of measurements, tread features extending laterally outward towards said radially projected sidewall surface within said shoulder region of interest having at least a predetermined depth and/or at least one common characteristic;
• comparing an aggregate notch depth of said identified tread features within said shoulder region of interest to a notch depth threshold to establish a presence of excessive tread wear within said shoulder region of interest;
• and
• responsive to a presence of excessive tread wear, generating an output to an operator representing said excessive tread wear.

A method for identifying worn tread shoulder regions on a tire having a tread surface extending circumferentially about an axis between a pair of radially projected sidewall surfaces, comprising:

• acquiring a plurality of measurements representative of tread depth within a region of interest extending both laterally and circumferentially over at least a portion of said tire tread surface, said region including at least a portion of one shoulder region and a portion of at least one of said sidewall surfaces;
• evaluating said plurality of measurements to identify at least one transition between said tread surface and said pair of sidewall surfaces;
• designating a shoulder region within said tread surface adjacent to said identified at least one transition;
• identifying, within said designated shoulder region, tread features having a generally lateral orientation;
• comparing a spatial density of said identified tread features within said designated shoulder region with a spatial density threshold to identify excessive tread wear within said designated shoulder region;
• and
• responsive to an identification of excessive tread wear within said designated shoulder region, generating an output representing said region of excessive tread wear.

A computer-implemented method to identify worn tread shoulder regions on a tire having a lateral tread surface extending circumferentially about an axis between a pair of radially projected sidewall surfaces, comprising executing with a programmed processor the steps of:

• acquiring a plurality of circumferentially spaced lateral rows of measurements representative of tread depth within a tire surface region of interest, said region of interest extending both laterally and circumferentially over at least a portion of said tire tread surface and including at least a portion of a shoulder region and an adjacent sidewall surface;
• establishing, for each of said plurality of lateral rows of measurements, an associated convex curve representative of said tire tread surface crown in the lateral direction, each of said associated convex curves composed of a plurality of lateral segments;
• evaluating, for each of said associated convex curves, slope values of adjacent lateral segments within each curve to identify transitions between sidewall surfaces, shoulder surfaces, and tire tread surfaces in response to changes in said slope values exceeding selected slope thresholds, whereby said identified transitions in each convex curve collectively define at least one shoulder region extending both laterally and circumferentially on said tire surface;
• locating, within said defined shoulder region, tread features having a generally lateral orientation;
• aggregating depth measurements for each of said laterally oriented tread features within said defined shoulder region to establish an aggregate notch depth estimate for said defined shoulder region;
• comparing said aggregate notch depth estimate with a depth threshold to identify excessive shoulder tread wear within said defined shoulder region;
• and
• responsive to an identification of excessive shoulder tread wear within said defined shoulder region, generating an output visually representing said excessive shoulder tread wear to an operator.