MEASURING METHOD AND MEASURING DEVICE

• US 20150254829A1
• Filed: 10/10/2013
• Published: 09/10/2015
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: Klaus Schmidt
• Original Assignee: Klaus Schmidt
• Inventors: Takahashi, Eiji, Araki, Kaname
• Granted Patent: US 9,704,237 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 13/00 Tyre sidewalls; Protecting, decorating, marking, or the like, thereof B60C17/08 takes precedence; tyre shoulders B60C11/01; removable tyre sidewall trim rings B60B7/01
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01B 11/2408 for measuring roundness
• CPC Class Codes: G01M 17/027 using light, e.g. infrared, ultraviolet or holographic techniques
• CPC Class Codes: G06T 2207/10004 Still image; Photographic image
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A measuring unit (301) acquires measurement data for a plurality of lines by repeatedly executing, on a reference tire, a measurement process to acquire measurement data for one line. A first acquisition unit (311) generates height data for one line for each of the plurality of sets of measurement data measured by the measuring unit (301), arranges the generated plurality of values of one-dimensional height data into a matrix form, generates two-dimensional height data for the measured face, and generates reference shape data. A second acquisition unit (314) acquires object one-dimensional height data from one-line shape data measured by the measuring unit (301) for the object tire. The measuring method and measuring device are characterized in that a removal unit (315) compares the object one-dimensional height data and the one-dimensional height data of the reference shape data at the same position in the sub-scan direction for the object one-dimensional height data, and removes, from the object one-dimensional height data, the height component of the projection.

Claims

1. A measuring method for measuring a surface form of a measurement surface, the measurement surface being a tread surface or a sidewall surface of a tire having a projection formed thereon, the method comprising:

a first measuring step of performing a measurement process a plurality of times while shifting a spotlight in a sub-scanning direction, and acquiring a plurality of pieces of measurement data, the measurement process including illuminating the measurement surface with the spotlight, scanning the measurement surface in a main-scanning direction with the spotlight, receiving reflected light, and acquiring measurement data for one line;

a first acquisition step of generating pieces of one-dimensional height data respectively from the plurality of pieces of measurement data, arranging the plurality of generated pieces of one-dimensional height data in a matrix, and generating two-dimensional height data of the measurement surface; and

a generation step of extracting the projection from the two-dimensional height data using an edge detection filter, associating a position of the extracted projection with the two-dimensional height data, and generating reference form data.

2. The measuring method according to claim 1, further comprising:

a second measuring step of performing the measurement process on the measurement surface of a target tire, which is a measurement object, and acquiring the measurement data for one line;

a second acquisition step of generating one-dimensional height data using the measurement data acquired in the second measuring step; and

a removal step of comparing target one-dimensional height data, which is the one-dimensional height data acquired in the second acquisition step, with one-dimensional height data in the reference form data, a corresponding position of which in the sub-scanning direction is the same as the target one-dimensional height data, and removing a height component of the projection from the target one-dimensional height data.

3. The measuring method according to claim 2, further comprising:

a run-out calculation step of calculating a difference between a maximum value and a minimum value of the target one-dimensional height data from which the height component has been removed in the removal step, as a run-out value of the target tire.

4. The measuring method according to claim 1, wherein

the edge detection filter is a Sobel filter.

5. The measuring method according to claim 1, wherein in a case where the measurement surface is the tread surface, the main-scanning direction is a circumferential direction of a tire, and the sub-scanning direction is a width direction of the tire, and

in a case where the measurement surface is the sidewall surface, the main-scanning direction is a direction concentric with a rotation axis of the tire, and the sub-scanning direction is a radial direction of the tire.

6. A measuring device that measures a surface form of a measurement surface, the measurement surface being a tread surface or a sidewall surface of a tire having a projection formed thereon, the measuring device comprising:

a measuring unit that performs a measurement process a plurality of times while shifting a spotlight in a sub-scanning direction, and acquires a plurality of pieces of measurement data, the measurement process including illuminating the measurement surface with the spotlight, scanning the measurement surface in a main-scanning direction with the spotlight, receiving reflected light, and acquiring measurement data for one line;

a first acquisition unit that generates pieces of one-dimensional height data respectively from the plurality of pieces of measurement data, arranges the plurality of generated pieces of one-dimensional height data, and acquires two-dimensional height data of the measurement surface; and

a generation unit that extracts the projection from the two-dimensional height data using an edge detection filter, associates a position of the extracted projection with the two-dimensional height data, and generates reference form data.