WO2018207265A1

WO2018207265A1 - Tire degradation evaluation system, and method and program thereof

Info

Publication number: WO2018207265A1
Application number: PCT/JP2017/017595
Authority: WO
Inventors: 日男吉川; 田中　賢治
Original assignee: 株式会社シーパーツ
Priority date: 2017-05-09
Filing date: 2017-05-09
Publication date: 2018-11-15
Also published as: JP2020041799A; JPWO2018207265A1

Abstract

According to the present invention, degradation of a material of a used secondhand tire is highly accurately evaluated by measuring a crack generated in a region of the tire, which has not been worn due to use of the tire. The present invention measures a displacement of a ground contacting surface of the tire to generate distance data (14) from which a crest part and a valley part of the ground contacting surface can be determined, captures an image of the ground contacting surface to generate ground contacting surface image data (15), extracts, from a region of the valley part, an evaluation region for detecting a crack to generate evaluation region image data (19), smoothing the resultant data and removes noise to generate smoothened image data (20), performs edge processing and clarifies the boundary part of the crack to generate edge-processed image data (21), calculates the ratio of the crack of the edge-processed image data (21) to the entire boundary part to generate crack ratio data (22), and outputs the crack ratio data (22).

Description

Tire deterioration evaluation system, method and program thereof

The present invention relates to a tire deterioration evaluation system, a method thereof, and a program thereof for evaluating deterioration of a used used tire through measurement of cracks.

In today's auto recycling industry, the shrinking market for used auto parts has been a concern, and promoting the use of used parts has been a challenge for many years. In Japan, the intention of new products is strong, and the idea of disposable is common. In particular, tires are consumables and demand is high, so it is said that the replacement cycle of new tires is fast, and the amount of waste tires that are no longer needed is said to be about 1 million tons per year. There are many. Although there are various disposal methods, there are concerns about the effects on the environment caused by chemical substances suspected of having endocrine disrupting effects that occur during incineration.
In such a background, there is no clear evaluation standard based on quantitative measurement of used and used tires, so it can be used based on the user's discretion and the ambiguous judgment standard by the inspection worker. However, there are many cases of disposal.
Therefore, it is considered that the distribution cycle of used and used tires can be further extended by providing a clear quality standard and deterioration evaluation system.
So far, several patent applications have been filed for tire quality inspection and wear evaluation.

For example, Patent Document 1 discloses an apparatus that automatically performs from detection of uneven tire wear to determination of countermeasures under the name of “tire uneven wear management method”.
In this invention, the tire shape is read by a scanner, compared with the new tire shape of the same tire, a differential shape is obtained, a partial wear database is searched based on the differential shape, and the presence and type of the partial wear is determined. After investigating the uneven wear, the tire position exchanging method and other countermeasure instructions extracted by searching the countermeasure database are displayed. Therefore, it is possible to reduce labor regardless of the experience and knowledge of the worker.

Further, in Patent Document 2, under the name of “tire wear monitoring device”, a different color rubber member for wear monitoring of a color different from that of the tread rubber layer is embedded at the bottom of the tread layer of the tire, and the tread surface is worn. By monitoring images, it is possible to monitor tire wear of a running vehicle and to easily grasp the time for tire replacement.

Furthermore, Patent Document 3 discloses a technology that can be accurately and efficiently inspected with a name of “tire inspection method and apparatus”, in which a defective portion can be easily and quickly found from a tire image without skill. Has been.
When inspecting a tire for good / bad on the basis of a black and white tone image signal obtained by imaging the tire with a laser-type nondestructive inspection machine and a CCD camera, etc., It detects, marks a defective part, and displays an image signal on a monitor.

Patent Document 4 discloses an invention for detecting and analyzing a crack generated on a side surface of a tire under the name “APPARATUS AND METHOD FOR TIRE SIDEWALL CRACK ANALYSIS”.
The present invention detects cracks generated on the side surface of a tire with an image, converts the image to gray scale, and then binarizes it into a black and white image, such as a jagged shape or a tapered shape in the binarized image. A discontinuous shape is detected, and the size of the crack is measured and evaluated.

Patent document 5 is by the applicant of the present application, and discloses an invention for detecting and analyzing cracks generated in a groove portion of a tire under the name of “tire deterioration evaluation device and system, method and program thereof”. Yes.
This invention pays attention to the crack generated in the groove which is an area that does not wear due to the use of the tire without directly contacting the road surface, and detects the groove while measuring the displacement of the ground contact surface of the tire and photographs the contact surface. Then, the image is binarized, the cracked portion in the groove is specified, the area of the cracked portion, the other area and the ratio thereof are obtained, and the deterioration of the tire material is evaluated with high accuracy.

JP 2009-102009 A JP 2006-123703 A JP 2001-13081 A US Patent Application Publication No. 2015/0139498 Japanese Patent Laying-Open No. 2015-161575

However, in the technique disclosed in Patent Document 1, although tire wear can be measured and evaluated, the appearance of used tire deterioration includes not only wear but also cracks, but such cracks cannot be measured and evaluated. There was a problem.
Further, even in the technique disclosed in Patent Document 2, since the different colored rubber member embedded in the bottom of the tread portion is exposed by the wear of the tread portion, the tire wear can be monitored even when the vehicle is running by the monitoring image of the tread surface. However, there is still a problem that it is impossible to measure and monitor the cracks that occur with the aging of the rubber material of the tire itself.
Furthermore, in the technique disclosed in Patent Document 3, when air is mixed between the top inners of the tires to be examined, when the binarization is performed, the portion becomes a white level, and the portion becomes a defective portion. Although it is easy to detect a defective part by marking as, the test tire is a new tire, and there is a problem that measurement / evaluation regarding deterioration that causes cracks with use or aging cannot be performed.
In both Patent Document 4 and Patent Document 5, a crack is photographed, and the degree of cracking is evaluated after performing monochrome binarization processing by the image processing. In particular, the crack generated in the groove is thin and linear. Therefore, there is a certain limit to finding the cracked part with high accuracy, and dust such as sand and pebbles may adhere to the surface including the tire groove when using the tire. In the case of detecting a crack, it becomes noise and this causes a decrease in accuracy.

The present invention has been made in response to such a conventional situation, and is a region where the deterioration of a used used tire is not worn by the use of the tire, i.e., a wear caused by traveling of the vehicle, not a mountain portion of the contact surface. By measuring cracks that occur in grooves that are not easily affected by damage, and processing the information related to cracks in a shape that conforms to the crack shape while eliminating noise, the deterioration of the tire material is highly accurate. An object of the present invention is to provide a tire deterioration evaluation system to be evaluated, its method, and its program.

In order to achieve the above object, the tire deterioration evaluation system according to the first aspect of the present invention is a displacement measurement that generates a distance data that enables a discrimination between a peak portion and a groove portion of the contact surface by measuring the displacement of the contact surface of the tire. An imaging unit for photographing the ground plane and generating ground plane image data; and an evaluation for detecting cracks from the groove area on the ground plane with reference to the distance data from the ground plane image data An evaluation region extraction unit that extracts a region and generates evaluation region image data; a smoothing processing unit that generates a smoothed image data obtained by smoothing the evaluation region image data to remove noise; and the smoothing An edge detection processing unit that generates edge-processed image data that clarifies the boundary of cracks by edge-processing the processed image data; and the entire boundary of cracks of the edge-processed image data A degradation evaluating portion that generates crack ratio data by calculating the Mel ratio, and has an output section for outputting the crack ratio data.
In the tire deterioration evaluation system having the above configuration, the displacement measuring unit measures the displacement of the ground contact surface of the tire and obtains distance data, thereby having an effect of enabling discrimination between the crest and the groove on the ground contact surface of the tire. In addition, the imaging unit has an effect of obtaining the image data by photographing the tire contact surface. Further, the evaluation area extraction unit operates to extract an evaluation area for detecting cracks from the ground plane image data while referring to the distance data.
The smoothing processing unit acts to smooth the noise with respect to cracks generated from the deposits on the tire surface and the data related to the surrounding image in advance, and to generate the data after the removal as smoothing processing data. The edge detection processing unit acts to edge-process the smoothed image data to clarify the boundary between cracks, and generate the clarified data as edge-processed image data.
As the smoothing process executed by the smoothing processing unit, for example, a Gaussian filter or the like can be employed. In addition, as an edge process executed by the edge process detection unit, a Canny method or the like can be adopted.
Since the groove portion does not come into contact with the road surface during normal vehicle travel, there is a high possibility that cracks will appear in that region, which will show aged deterioration that does not depend on the wear of rubber, which is the material of the tire. Therefore, in order to measure the crack in the groove portion in particular, the ground plane is photographed while measuring the displacement of the ground plane, and distance data and ground plane image data are acquired. Then, an evaluation area is extracted from the groove area using the ground plane image data while referring to the distance data, and noise is first removed from the ground plane image data within the evaluation area by a smoothing process, and then an edge is extracted. Cracks are detected by detection.
The groove is not in contact with the road surface and the color of the internal rubber is visible in the cracks that are occurring, so it is usually measured as black. On the other hand, the groove in the portion where no crack is generated is grayed out due to deterioration from the original black color. Therefore, in the tire deterioration evaluation system according to the present invention, the edge detection processing unit detects the boundary between black and gray as an edge, and acts to recognize a portion where the color of the internal rubber is visible as a crack. It is.

In the present invention, the displacement measurement unit and the imaging unit are separated. However, when a distance image sensor as disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-179925 is employed, the distance image sensor is a displacement measurement unit. Therefore, even if a distance image sensor is employed, it does not depart from the scope of the present invention.
In the present invention, a component including the word “part”, such as a displacement scanning measurement unit, is used. The “part” means “element”, “electronic circuit”, or “unit of component”. Or “apparatus in which they are assembled”.

Further, in the tire deterioration evaluation system according to the second invention, in the first invention, the deterioration evaluation unit evaluates the ratio with evaluation threshold data predetermined in order to evaluate deterioration, and evaluation rank data. , And the output unit outputs the evaluation rank data.
In the tire deterioration evaluation system having the above configuration, in addition to the operation of the first invention, the deterioration evaluation unit operates to rank-evaluate the ratio of the entire crack boundary using the evaluation threshold data.

In the tire deterioration evaluation system according to the third aspect of the present invention, in the first or second aspect of the invention, the displacement measurement unit calculates the width of the groove portion of the ground contact surface of the tire from the distance data, thereby obtaining groove width data. A groove width calculation unit that generates a groove depth calculation unit that calculates the depth of the groove from the distance data and generates groove depth data, and generates groove number data relating to the number of the groove parts, The output unit outputs at least one of the groove width data, the groove depth data, and the groove number data.
In the tire deterioration evaluation system having the above configuration, in addition to the operation of the first or second invention, the groove width calculation unit operates to calculate the groove width, and the groove depth calculation unit calculates the groove depth. The displacement measuring unit, in combination with the output unit, acts to more specifically grasp the groove structure on the ground contact surface of the tire.

Furthermore, in the tire deterioration evaluation system according to a fourth aspect of the present invention, in any one of the first to third aspects, the output unit is generated by the data generated by the deterioration evaluation unit and the imaging unit. The ground contact surface image data or the evaluation region image data extracted by the evaluation region extraction unit is output at the same time.
In the tire deterioration evaluation system configured as described above, in addition to the operation of any one of the first to third aspects of the invention, the output unit is an evaluation object and data relating to evaluation such as digital values such as numerical values and ranks and characters. By outputting the original ground plane image data or the evaluation area image data at the same time, the validity including the possibility of the evaluation error is confirmed. Moreover, it acts so that the state of the tire surface can be grasped from both sides of text information such as numerical values and characters and image information.

According to a fifth aspect of the present invention, there is provided a tire deterioration evaluation method, comprising: a displacement measuring step of measuring a displacement of a ground contact surface of a tire to generate distance data that enables discrimination between a ridge and a groove of the contact surface; An imaging process for capturing and generating ground plane image data, and extracting an evaluation area for detecting cracks from the groove area on the ground plane with reference to the distance data from the ground plane image data An evaluation area extracting step for generating image data, a smoothing process step for generating smoothed image data obtained by smoothing the evaluation area image data to remove noise, and edge processing for the smoothed image data Edge detection processing step for generating edge-processed image data in which the boundary of cracks is clarified, and the ratio of the edge-processed image data to the entire boundary of cracks is calculated. Such deterioration evaluation step of generating cracks ratio data, those having an output step of outputting the crack ratio data.
In the tire deterioration evaluation method with the above configuration, the first invention is regarded as the method invention, and thus the operation thereof is the same as that of the first invention.

In the tire deterioration evaluation method according to a sixth aspect of the present invention, in the fifth aspect of the invention, the deterioration evaluation step generates evaluation rank data by evaluating the ratio with evaluation threshold data set in advance in order to evaluate the deterioration. And the said output process outputs the said evaluation rank data, It is characterized by the above-mentioned.
Since the tire deterioration evaluation method with the above configuration is based on the second invention as a method invention, its operation is the same as that of the second invention.

In the tire deterioration evaluation method according to a seventh aspect of the present invention, in the fifth or sixth aspect of the invention, the displacement measuring step calculates a width of the groove portion of the ground contact surface of the tire from the distance data. A groove width calculation step for generating a groove depth calculation step for calculating the depth of the groove portion from the distance data and generating groove depth data, and generating groove portion number data relating to the number of groove portions, In the output step, at least one of the groove width data, the groove depth data, and the groove number data is output.
Since the tire deterioration evaluation method with the above configuration is based on the third invention as a method invention, the operation thereof is the same as that of the third invention.

The tire deterioration evaluation method according to an eighth aspect of the present invention is the tire deterioration evaluation method according to any one of the fifth to seventh aspects of the invention, wherein the output step includes data generated in the deterioration evaluation step and the imaging step. The generated ground plane image data or the evaluation area image data extracted in the evaluation area extraction step is simultaneously output.
In the tire deterioration evaluation method having the above-described configuration, the tire deterioration evaluation system according to claim 4 is an invention that is captured as a method invention, and thus the operation thereof is the same as that of the fourth invention.

A tire deterioration evaluation program according to a ninth aspect of the present invention is a program executed by a computer for tire deterioration evaluation, wherein the displacement of the tire contact surface is measured to discriminate between the peak portion and the groove portion of the contact surface. A displacement measuring step for generating distance data to be enabled; an imaging step for photographing the ground plane to generate ground plane image data; and the groove portion on the ground plane with reference to the distance data from the ground plane image data An evaluation region extraction step for generating an evaluation region image data by extracting an evaluation region for detecting cracks from the region, and smoothing processing image data in which noise is removed by smoothing the evaluation region image data Smoothing processing step, and edge detection for generating edge processed image data in which the boundary portion of the crack is clarified by performing edge processing on the smoothed image data Performing a physical process, a deterioration evaluation process for calculating a ratio of the entire boundary of cracks in the edge-processed image data to generate a crack ratio data, and an output process for outputting the crack ratio data. It is a feature.
Since the tire deterioration evaluation program having the above configuration is an invention in which the fifth aspect of the invention is regarded as a program invention, the action thereof is the same as that of the fifth aspect of the invention.

In the tire deterioration evaluation system according to the first invention, it is possible to measure the cracks occurring in the groove portion of the tire contact surface, and therefore it is possible to quantitatively evaluate the aging deterioration that does not depend on the wear of the tire rubber. . Also, while measuring the displacement of the ground plane by the displacement measurement unit and obtaining distance data, the image plane also obtains the ground plane image data, so that the groove portion of the ground plane can be detected from these data and cracks generated in the groove portion are obtained. Can be measured with high accuracy.
In addition, since the evaluation area is extracted in advance in the groove area and the noise removal process is performed thereafter, it is possible to prevent the occurrence of noise due to tire deposits such as sand and pebbles. Therefore, it is possible to prevent overestimation against deterioration due to noise that is likely to occur in a used tire with a low degree of deterioration.
Furthermore, since the edge detection process is performed, it is possible to detect a crack in accordance with the substance of the crack portion that is generated at a location that is not in direct contact with the road surface, such as a groove portion of the ground contact surface.
Since the edge detection process is performed after the smoothing process and the ratio of the total crack boundary is calculated to generate the crack ratio data, it is suitable for the actual cracks in the groove not installed on the road surface. Thus, the crack ratio can be measured with high accuracy.

In the tire deterioration evaluation system according to the second invention, in addition to the effects of the first invention, evaluation rank data is generated. Therefore, it is possible to rank evaluations for tire deterioration and classify into ranks. It is possible. In this way, if classification into ranks is possible, the tires can be ranked according to the deterioration state of the tires, and an effect that the utility value becomes high as a measure of the price in the secondary tire distribution market can be expected. Furthermore, the degree of classification of the rank can be changed according to the degree of subdivision of the evaluation threshold data for the evaluation rank, and the utility value is increased as a maintenance index such as a tire replacement guide in addition to the price in the market. effective. Therefore, it is possible to improve the safety and economy of the tire.

In the tire deterioration evaluation system according to the third invention, in addition to the effects of the first or second invention, at least one data of the groove width, the groove depth, and the number of groove parts is output to the output part. It is possible for the user of this system to obtain specific information regarding the structure of the tire groove that is the object of evaluation.

In the tire deterioration evaluation system according to the fourth invention, in addition to the effects of any one of the first to third inventions, it is possible to confirm the validity of the evaluation, and the tire surface is represented by numerical values or characters. The user of this system can easily and accurately grasp the deterioration state of the tire from both the text information such as the above and the image information regarding the groove portion to be evaluated.

Since the tire deterioration evaluation method according to the fifth invention is an invention based on the first invention as a method invention, the effect is the same as the effect of the first invention.

Since the tire deterioration evaluation method according to the sixth invention is an invention based on the second invention as a method invention, the effect is the same as the effect of the second invention.

Since the tire deterioration evaluation method according to the seventh invention is an invention based on the third invention as a method invention, the effect is the same as the effect of the third invention.

Since the tire deterioration evaluation method according to the eighth invention is an invention based on the fourth invention as a method invention, the effect is the same as the effect of the fourth invention.

Since the tire deterioration evaluation program according to the ninth invention is an invention in which the fifth invention is regarded as a program invention, the effect is the same as the effect of the fifth invention.

1 is a block diagram of a tire deterioration evaluation system according to a first embodiment of the present invention. It is a flowchart of the tire deterioration evaluation performed by the tire deterioration evaluation system which concerns on the 1st Embodiment of this invention. (A) is a conceptual diagram of the tire contact surface image data obtained by the imaging unit of the tire deterioration evaluation system according to the first embodiment of the present invention, (b) is a symbol A in (a) It is a conceptual diagram of evaluation area image data shown in a black frame, (c) is a conceptual diagram of image data when the evaluation area image data of (b) is subjected to monochrome binarization processing, and (d) is (b) 3 is a conceptual diagram of edge processed image data when edge processing is performed on evaluation area image data of FIG. (A) is an evaluation area image data conceptual diagram of the S rank tire used for evaluating the tire deterioration evaluation system according to the first embodiment of the present invention, and (b) is similarly A rank It is a tire evaluation area image data conceptual diagram, (c) is also a B rank tire evaluation area image data conceptual diagram, (d) is also a C rank tire evaluation area image data conceptual diagram. (E) is an evaluation region image data conceptual diagram of a D rank tire in the same manner. It is a table | surface which shows the result of having measured the crack ratio of each tire of S, A, B, C, D rank used in order to evaluate the tire deterioration evaluation system which concerns on the 1st Embodiment of this invention. It is a graph which shows the measurement result of FIG. It is a figure which shows the correspondence of rank division at the time of using crack ratio data as a deterioration evaluation value, ie, it is also a figure which shows evaluation threshold value data. (A)-(c) is a conceptual diagram which shows the example of the acquisition location of the contact surface image data of the tire degradation evaluation system based on the 1st Embodiment of this invention, respectively. It is a table | surface which shows the result of having evaluated a used tire using the tire deterioration evaluation system which concerns on the 1st Embodiment of this invention. (A) And (b) is a conceptual diagram which shows the example of the evaluation result displayed by the output part of the tire degradation evaluation system which concerns on the 1st Embodiment of this invention, respectively.

The tire deterioration evaluation system according to the first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a block diagram of a tire deterioration evaluation system according to a first embodiment of the present invention. FIG. 2 is a flowchart of tire deterioration evaluation executed by the tire deterioration evaluation system according to the first embodiment of the present invention. This figure also represents the execution process for the tire degradation evaluation method and program of the present invention. Explaining the flow of data processing in the tire degradation assessment system 1 with reference to this figure is a tire degradation assessment. It is synonymous with describing the embodiment of the method and program. In FIG. 2, what is indicated by a broken line so as to cover the description about the process indicated by S is a component of the tire deterioration evaluation apparatus 1 shown in FIG.
In FIG. 1, the tire deterioration evaluation system 1 includes a processing database 6 and an evaluation database 7 as a displacement scanning measurement unit 4, an imaging unit 5, a processing unit 3, an output unit 2, and a database group. The tire deterioration evaluation system 1 can be assumed to be a portable system that can be evaluated by bringing these components together into a hand and taking it close to the surface of the ground contact surface of a used tire. In this case, the output unit 2 may be a small display device or a data transmission unit that transfers data to another device. Alternatively, even if the components shown in FIG. 1 are not integrated, the displacement measuring unit 4 and the imaging unit 5 are separated as sensors and provided separately, and the system transmits data to the processing unit 3 by wire or wirelessly. Is possible. Further, the used tire is transported into a housing having at least a displacement scanning measurement unit 4 and an imaging unit 5 inside to acquire data, and the processing unit 3 evaluates based on the data and outputs the result to the output unit 2. It is possible to envisage a system or the like.

Hereinafter, a description will be given with reference to FIGS.
The displacement scanning measurement unit 4 of the tire deterioration evaluation system 1 is arranged perpendicular to the ground contact surface on which a so-called tread pattern of the tire is formed, and can distinguish a peak portion and a groove portion of the tread pattern formed on the ground contact surface. The unevenness is measured by scanning the sensor in the width direction of the ground contact surface of the tire. Specifically, it is measured as distance data 14 with respect to the displacement scanning measurement unit 4. Therefore, if the difference between the distance data of the peak portion and the groove portion is taken, it is possible to obtain the depth of the groove portion relative to the peak portion or the height of the peak portion relative to the groove portion. That is, a so-called remaining groove can be obtained. As a sensor used as the displacement scanning measurement unit 4, it is possible to use a sensor that radiates electromagnetic waves such as laser light and infrared rays and ultrasonic waves and detects the reflected waves to measure the distance. Further, since the displacement scanning measurement unit 4 is configured to scan the ground contact surface of the tire, it is possible to perform a distance measurement that makes it possible to discriminate between a peak portion and a groove portion of the tread pattern over the width of the tire. It is the displacement measurement process of step S1 that measures the displacement on the ground contact surface of the tire using the displacement scanning measurement unit 4.
The displacement scanning measurement unit 4 stores the distance data 14 in the processing database 6 so that it can be read out.
In this embodiment, the displacement scanning measurement unit 4 that can be scanned is used as the displacement measurement unit, but the height of the crest and the depth of the groove in the width direction of the tire contact surface can be measured without scanning. It is sufficient if it is possible, and it is not always necessary to be able to scan.

In this embodiment, the displacement of the tire contact surface is measured not only by quantitatively measuring the depth of the remaining groove (remaining groove), but also by the tread pattern on the tire contact surface. This is for grasping the position of the groove and photographing an image for measuring cracks and cracks in the groove. The reason why the groove portion is thus selected and measured will be described. Unlike used tires, used tires handled by the present invention are worn out by using the ground contact surface. Therefore, cracks due to deterioration over time are unlikely to occur, and on the other hand, sudden damage or chipping may occur at the peak portion of the contact surface with use. These scratches and chips are also important for tire quality, so detection is of course important, but if you try to detect cracks and cracks associated with pure deterioration of the rubber material due to aging itself, errors are likely to occur, and aging evaluation It is difficult to ensure high accuracy against
Therefore, focusing on the cracks and cracks generated in the groove portion of the ground contact surface that does not contact the ground even under normal use, it was decided to evaluate the aging deterioration by the cracks and cracks generated in the groove portion.
In order to be able to select the groove portion accurately, it is necessary to measure the displacement so that the peak portion and the groove portion of the tread pattern can be distinguished.

The imaging unit 5 captures a tire ground contact surface including a tread pattern, and an already known CCD sensor or CMOS sensor can be used. The imaging unit 5 may also have a scanning function, but since the imaging device can capture an image in a plane, the scanning function is often unnecessary. It is the measurement target imaging process in step S2 that the tire contact surface is photographed using the imaging unit 5.
The imaging unit 5 stores the ground plane image data 15 relating to the photographed ground plane in the processing database 6 so as to be readable.
The groove width calculation unit 8 of the processing unit 3 reads the distance data 14 obtained by the displacement scanning measurement unit 4 from the processing database 6 and takes the difference in the tire width direction to obtain the groove width data 16 and the groove number data 18. Is stored in the processing database 6 so as to be readable, and the process is the groove width calculation process in step S3. Further, the groove depth calculation unit 9 of the processing unit 3 reads the distance data 14 obtained by the displacement scanning measurement unit 4 from the processing database 6, and the height direction of the mountain and the depth direction of the valley of the tread pattern of the tire. Thus, the groove depth data 17 is generated and stored in the processing database 6 so as to be readable, and this process is the groove depth calculation process in step S4.
The groove width calculation unit 8 and the groove depth calculation unit 9 obtain data on the position in the width direction of the tire from the distance data 14, and include the position data, the groove width data 16, the groove depth data 17, and the groove part. Each of the numerical data 18 is generated.
In the present embodiment, the displacement scanning measurement unit 4, the groove width calculation unit 8, and the groove depth calculation unit 9 are provided separately. However, the displacement scanning measurement unit 4 having all functions may be integrated. In that case, what is necessary is just to combine step S1, step S3, and step S4 into a displacement measurement process (S1).

The imaging unit 5 generates the ground plane image data 15 and stores it in the processing database 6 so that it can be read out. This process is the measurement target imaging process in step S2. The actual used tire surface is as shown in FIG. Although it may be difficult to see in this photograph, there is a crack in the groove 26 formed perpendicular to the center. However, since the hill portion of the tire comes into contact with the road surface and friction and wear occur, it seems that cracks and cracks have not occurred, and at the same time, fine scratches caused by the contact with the road surface can be observed. As can be seen from FIG. 3A, the cracks in the groove portion 26 that are not in contact with the road can be observed as a thinly connected shape, but the flaws in the mountain portion do not show an elongated shape, and are point-like shapes that are close to a circle or a rectangle. Can be observed.
In the present embodiment, the distance data 14 and the ground plane image data 15 are obtained by using separate sensors such as the displacement scanning measurement unit 4 and the imaging unit 5, but as described above, the distance having these two functions. An image sensor or the like may be provided to obtain the distance data 14 and the ground plane image data 15 from one sensor.

The evaluation region extraction unit 10 of the processing unit 3 reads the ground plane image data 15 from the processing database 6, selects a groove portion of the ground plane from the ground plane image data 15, and extracts an evaluation region in the groove portion 26. The process is the evaluation region extraction process in step S5. When selecting the groove 26, the evaluation area extraction unit 10 reads the groove width data 16, the groove depth data 17, and the groove number data 18 to determine where the groove 26 exists on the tire contact surface. It is possible to judge about.
FIG. 3 (a) conceptually shows a state in which the groove 26 is selected and the evaluation region is extracted, and a black square range indicated by reference numeral A in FIG. 3 (a). b).
The evaluation area extraction unit 10 stores the data related to the evaluation area determined in the ground plane image data 15 as the evaluation area image data 19 so as to be readable in the processing database 6.

The smoothing processing unit 11 reads the evaluation area image data 19 from the processing database 6 and performs noise removal by smoothing on the evaluation area image data 19 extracted in the groove portion of the ground plane image data 15. The process is the noise removing process of step S6. Since the object to be measured is a used tire, there are various deposits on the surface. When the color of the deposit is black, cracks generated in the groove 26 are black as shown in FIG. As a result, when processing an image, it rides as noise.
Furthermore, in the present embodiment, since the crack detection step S7 by the edge detection processing unit 12 is reserved after the noise removal step S6 by the smoothing processing unit 11, the color of the groove 26 is not limited to black but white. If the difference is large, it is detected as an edge, so it is necessary to remove noise caused by white deposits.
Therefore, in order to eliminate noise caused by deposits such as white sand or black sand or pebbles that have a large difference from the average color of the groove 26 and improve the accuracy of deterioration measurement / evaluation, the surrounding pixels for each pixel. It is important to smooth the image in a range including
The evaluation area image data 19 from which noise has been removed by the smoothing processing unit 11 is stored as smoothed image data 20 in the processing database 6 so as to be read out.

Next, the edge detection processing unit 12 reads the smoothed image data 20 from the processing database 6 and detects a cracked portion by edge detection processing on the smoothed image data 20 from which noise has been removed. The process is the edge detection process in step S7.
In the tire deterioration evaluation system 1 according to the present embodiment, cracks and cracks generated in the groove portion 26 of the used tire are detected, and the state appears as a long and continuous line as shown in FIG. . Therefore, when trying to quantitatively evaluate the cracks and cracks, it is important to accurately measure the wrinkle portion, that is, the boundary portion, quantitatively and evaluate based on the amount.
The inventors convert the image of the cracked state of the groove portion 26 into a monochrome binary image in the patent application shown in Patent Document 5, and perform quantitative evaluation of the crack using the area ratio of the data of the white image and the black image. However, the inventors have found that there is still room for improvement in accuracy, and have arrived at the present invention.

This will be specifically described with reference to FIGS. 3 (a) to 3 (d).
As described above, FIG. 3A shows the contact surface image data 15 obtained by photographing the contact surface of the tire by the imaging unit 5, and FIG. 3B is an evaluation region indicated by a black frame indicated by the symbol A in FIG. Although it is a conceptual diagram of the image data 19, it is (c) and (d) which processed and compared with this evaluation area image data 19 in two ways.
(C) is the conceptual diagram of the image data at the time of carrying out the monochrome binarization process of the evaluation area | region image data 19 with the technique disclosed by patent document 5, (d) is the tire degradation evaluation system 1 which concerns on this Embodiment. This is a conceptual diagram of edge-processed image data when edge processing is performed on the evaluation area image data 19 by the edge detection processing unit 12.
As apparent from a comparison between FIGS. 3C and 3D, FIG. 3D is approximated by the evaluation area image data 19 in FIG. Since the crack generated in the groove 26 of the tire is not in contact with the road surface, it is possible to observe pure deterioration of the rubber material due to the aging of the tire itself, and the shape of the crack or crack in that case is elongated and continuous. In order to quantitatively evaluate this, image processing that can be quantified according to the shape is necessary, and the inventors have performed processing by edge detection to detect the boundary of cracks. Since it was detected with high accuracy, it was found that it was suitable for quantitative evaluation of cracks, leading to the present invention.
In (c), depending on how the threshold value of the binarization process in the groove 26 is set, noise due to sand, pebbles, etc. turns white or black, and therefore it is necessary to set an individual threshold value for each tire. In some cases, it is difficult to grasp the overall shape of cracks through multiple used tires. Therefore, when the color changes (wrinkles), that is, the tire deterioration evaluation system 1 including the edge detection processing unit 12 that detects the boundary as an edge is consistently more accurate for all tires in the groove portion. Cracks can be detected.
The smoothed image data 20 edge-processed by the edge detection processing unit 12 is stored in the process database 6 as edge-processed image data 21 so as to be readable.
The deterioration evaluation unit 13 reads the edge processing image data 21 obtained as shown in FIG. 3D from the processing database 6, and from the edge processing image data 21, the area of the edge portion expressed in white and the other expressed in black The ratio of the total area including this part is calculated, and the ratio is generated as crack ratio data 22 and stored in the processing database 6.
As described above, in the present invention, focusing on the boundary of cracks, the ratio of the area of the boundary to the entire area is quantified as crack data 22, and the degree of tire deterioration is evaluated by the magnitude of this numerical value. . Therefore, for example, when the crack is wide and large, it is considered that the evaluation by extracting the boundary portion of the crack does not lead to the evaluation of the entire crack. However, if the cracks are large, it is no longer a stage to evaluate deterioration, but it is a level that requires immediate disposal of the tire and replacing it with a new tire. Therefore, it can be handled as an object of evaluation according to the present invention, and there is no inconvenience in using the present invention.

Further, the deterioration evaluation unit 13 reads the evaluation threshold data 23 stored in advance in the evaluation database 7, evaluates the crack ratio data 22 obtained by the deterioration evaluation unit 13, and generates evaluation rank data 24. Store in database 7.
Specifically, the evaluation threshold value data 23 includes a threshold value of the crack ratio data 22 with respect to a predetermined rank, and the crack ratio data 22 is evaluated by comparing the threshold value and the crack ratio data 22 and assigning them to ranks. To do.
The step of calculating the crack rate data 22 by the deterioration evaluation unit 13 and the step of evaluating the crack rate data 22 as a rank using the evaluation threshold data 23 are step S8.
The ranking shown by the deterioration evaluating unit 13 can classify the tires into ranks according to the deterioration state of the tires, and exhibits an effect that it is easy to understand as an index. Therefore, for example, the utility value as a measure of the price in the secondary tire market and the utility value as a measure of tire replacement are increased, and the safety and economy of the used tire can be improved. Since the rank can be changed roughly or in detail as desired by widening or narrowing the interval between the thresholds in the evaluation threshold data 23, it is possible to rank according to the purpose. Note that the rank may be expressed in any of alphabets such as A and B, A and B, kanji such as suitability, and numbers such as 1 and 2.

The output unit 2 outputs any data obtained as a result of each processing content executed by each unit included in the processing unit 3 alone or in combination as the direct output data 25, or reads and outputs data from each database. The data 25 is output to the outside, and this process is the output process of step S9. Specific examples of the output unit 2 include a display device such as a CRT, liquid crystal, plasma, or organic EL, an output device such as a printer device, and a transmitter such as a transmitter for transmission to an external device. . Of course, it may be an interface for output for transmission to an external device.
The processing database 6 includes distance data 14, ground plane image data 15, groove width data 16, groove depth data 17, groove number data 18, evaluation area image data 19, and smoothed image data 20 processed by the processing unit 3. This is a database that stores the edge-processed image data 21 and the crack ratio data 22 in a readable manner.
The evaluation database 7 is a database in which the evaluation threshold data 23 used for the tire deterioration evaluation by the deterioration evaluation unit 13 and the evaluation rank data 24 after the evaluation are stored in a readable manner.
As described above, according to the tire deterioration evaluation system 1 according to the present embodiment, the crest portion and the groove portion 26 on the ground contact surface of the tire are discriminated, and cracks in the groove portion 26 that are not affected by wear due to use of the tire are detected. It is possible to measure cracks with high accuracy. Therefore, it is possible to measure only cracks and cracks caused by the influence of aging deterioration, and it is possible to perform quantitative deterioration evaluation with high accuracy. Furthermore, as already described, rank evaluation is also possible by the degradation evaluation unit 13. In the present embodiment, the invention has been described as a system. However, the process of processing data using the system can be considered as a method invention or a program invention for executing a computer. The effect is the same as that of the system invention already described.

Next, a test was performed using a prototype system to determine how used tires were ranked by the degradation evaluation unit 13 of the tire degradation evaluation system 1 according to the present embodiment. A description will be added with reference to FIG.
FIGS. 4A to 4E show evaluation region images of tires of S, A, B, C, and D ranks, respectively, used for evaluating the tire deterioration evaluation system according to the first embodiment. It is a data conceptual diagram.
Rank SD for the image shown in FIG. 4 is a cracked state in the groove portion 26 of the ground contact surface of a used tire determined by the applicant as an example. Each rank of tire shown in FIG. It is evaluated and ranked by those who are engaged in tire sorting.
FIG. 5 shows the crack ratio data 22 obtained using the prototype system for the tires of the respective ranks shown in FIG. 6, and FIG. 6 is a graph of this data. The numbers described below each rank in FIG. 5 and the numbers described on the vertical axis in FIG. 6 indicate the crack ratio data 22 in percentage (%). The numbers described below the graph of FIG. 6 are the same as the numbers indicating the measurement location described at the left end of FIG.
In the present embodiment, a Gaussian filter is used in the smoothing processing in the smoothing processing unit 11, and the Canny method is used in the edge detection processing in the edge detection processing unit 12. The same processing applies to the image shown in FIG.
As shown in FIG. 5, the number of measurements is different for each of the ranks SD, but this does not have a particular purpose. The median is the median value in the measurement value group of each rank, and the average value is also the average value in the measurement value group of each rank.
Also, the solid line shown in FIG. 6 connects the median values of the measurement value groups in each rank, and the dotted line expresses the median value of the measurement value groups in each rank as a primary linear format.

From Fig. 5, the crack ratio of rank S is 0.479126 on average, which is higher than the average value of crack ratio of rank A, 0.292188, but the crack ratio gradually increases from rank A to rank D. To get the result. The reason why the crack ratio of rank S is high is that there is almost no crack in rank S and rank A, and there is almost no difference in the degree of tire deterioration. Is considered to be evaluated. Although the result is that degradation is smaller in rank A, it can be said that the crack ratio data 22 of rank S and rank A is actually a slight difference because they are values smaller than 0.5%.
From the results shown in FIG. 5 and FIG. 6, the inventors have a correlation between the crack ratio data 22 obtained using the tire deterioration evaluation system 1 and the rank of the tire selected by the expert. It was found that by obtaining the crack ratio data 22, it is possible to classify the tires into ranks SD of tires selected by experts.

FIG. 7 shows the correspondence of ranking when the crack ratio data 22 obtained as a result of analysis including other test results in addition to FIGS. 5 and 6 is used as the deterioration evaluation value. Therefore, FIG. 7 also shows the contents of the evaluation threshold data 23.
As is clear from FIG. 7, in the tire deterioration evaluation system 1 according to the present embodiment, the case where the value of the crack ratio data 22 is 0.5 or less is evaluated as the S rank, and is larger than 0.5 and smaller than or equal to 2.0. Cases are evaluated as A ranks, and from B to D ranks in the same manner.
As described above, the deterioration evaluation unit 13 reads the crack ratio data 22 from the processing database 6 and determines which of the deterioration evaluation value ranges of the evaluation threshold data 23 shown in FIG. The corresponding rank is generated as evaluation rank data 24 and stored in the evaluation database 7 so as to be readable.

In addition, it is desirable that the tire contact surface measurement by the tire deterioration evaluation system 1 is performed at a plurality of locations in the tire circumferential direction. FIGS. 8A to 8C show an example in which the tire deterioration evaluation system 1 performs measurement. When measurement is performed every 90 ° and four points are measured, measurement is performed every 45 °. In the case where measurement is performed at 8 locations, the measurement is performed every 30 ° and 12 measurements are performed.
In the portable tire deterioration evaluation system 1, since it is assumed that the measurement person holds the measurement in his hand, it may be difficult to measure at an accurate angular interval as shown in FIG. It is not necessary to carry out at equal intervals, and it is only necessary to improve the accuracy by measuring a plurality of times with one tire.
Of course, a system in which the displacement scanning measurement unit 4 and the imaging unit 5 of the tire deterioration evaluation system 1 are fixed and the tire itself is automatically rotated by a certain angle to acquire the distance data 14 and the contact surface image data 15. It is good.

The result of evaluating an actual used tire using the tire deterioration evaluation system 1 described above will be described with reference to FIG.
FIG. 9 is a table in which the tire deterioration evaluation system 1 is used to measure 8 points for every 45 ° shown in FIG.
In FIG. 9, “shot” means a unit in which the distance data 14 and the contact surface image data 15 are acquired, and 1-8 of the measurement points are selected every 45 ° along the circumferential direction of the used tire as described above. This means The position indicates the distance (mm) from the inside of the tire as the position of the groove 26 to be measured, the size indicates the groove width (mm) multiplied by 10, and the depth indicates the groove depth. The thickness (mm) is indicated by 10 times. In addition, it turns out that the number of grooves is 3 in any of the eight measurement locations. From the above, size corresponds to the groove width data 16 in the system diagram of FIG. 1, depth corresponds to the groove depth data 17, and the number of grooves 3 corresponds to the groove number data 18.
Further, in the column of the degradation evaluation value in FIG. 9, the crack ratio data 22 in each groove is displayed as a percentage (%). Since the median value for the crack ratio data 22 at these eight locations is 2.379115 as described in the lower right column of the table, the deterioration evaluation unit 13 of the tire deterioration evaluation system 1 is shown in FIG. The evaluation threshold value data 23 shown is read and used to evaluate the tire rank as B, and is displayed in the lower right column of FIG. The tire rank is stored as evaluation rank data 24 so as to be readable in the evaluation database 7.

Finally, an example of output from the output unit 2 of the tire deterioration evaluation system 1 will be described with reference to FIG. FIGS. 10A and 10B are conceptual diagrams illustrating examples of evaluation results displayed by the output unit 2.
In FIG. 10A, the displayed image displays the ground plane image data 15 on the left side and the evaluation result on the right side. “B565” indicated by the symbol B is “B”. Is the evaluation rank data 24, and “565” indicates that the number of grooves is 3 and the groove depth data 17 is 5 mm, 6 mm, and 5 mm from the inside of the tire.
In addition, what is indicated by the symbol C is a graph showing the tendency of the groove depth data 17 of 5 mm, 6 mm, and 5 mm, and the inside of the tire is also on the left side.
Furthermore, a set of plot points indicated by reference sign D represents the deterioration evaluation value (crack ratio data 22) shown in FIG.
Thus, since the data of the groove depth is displayed together with the number of grooves, it is possible for the user of the system to obtain specific information on the structure of the tire groove that is the object of evaluation, By displaying the ground contact surface image data 15 together, it is possible to observe the state of the groove while comparing the image with the measured value and the evaluation rank. Therefore, it is easy to visually evaluate the deterioration of the tire, and the validity of the evaluation result by the system is confirmed. It is also possible to do.
By showing the groove depth data 17 for each tire groove in accordance with the arrangement of the tire grooves, it is possible to grasp the state of uneven wear caused by how the tire user rides the vehicle, the degree of air pressure, and the like.

Next, in FIG. 10B, the displayed image is from a display window different from that in FIG. 10A, and what is indicated by the symbol E on the left is the groove width data 16 in units of mm. , F is the groove depth data 17 indicated in units of mm, and the distance data 14 indicating the state in which the entire tire is traced in the width direction is shown on the right side from the center.
In the distance data 14, the symbol G in the figure indicates the distance in the tire width direction from the inner end of the tire in units of mm, and the symbol H indicates the normal direction with respect to the outer circumference of the tire, that is, the valley height of the tire. The distance in the direction of the groove depth is shown in units of mm.
By also displaying the information shown in (b), it is possible to check the groove state of the tire surface over the entire width direction of the tire, and coupled with the evaluation result, the tire deterioration state with higher accuracy. Can be grasped.
In the tire deterioration evaluation system 1 according to the present embodiment, since both the screens (a) and (b) are displayed as the output unit 2, the amount of information provided to the user is large, and risks such as misidentification and misunderstandings. It is possible to provide a system that can reduce human error and reduce human error.
In the present embodiment, the data shown in FIGS. 10A and 10B are displayed. However, other data stored in the processing database 6 and the evaluation database 7 are appropriately read and output. The display or transmission may be performed by the unit 2.
Further, in the present embodiment, the arrangement of the tire grooves is displayed with the left side corresponding to the inner side of the tire grooves, but the order may be reversed and may be changed for convenience during use or design.

As described above, the invention described in claims 1 to 9 of the present invention can quantitatively evaluate the deterioration of used tires, and the owner can perform tire maintenance or taxi for private cars. It can be widely used by companies and bus companies for maintenance of their own commercial vehicles, maintenance and inspection of customer cars by car dealers and private car factories, and assessment of tire value by used car dealers. .

DESCRIPTION OF SYMBOLS 1 Tire deterioration evaluation system 2 Output part 3 Processing part 4 Displacement scanning measurement part 5 Imaging part 6 Processing database 7 Evaluation database 8 Groove width calculation part 9 Groove depth calculation part 10 Evaluation area extraction part 11 Smoothing process part 12 Edge detection process Part 13 Degradation evaluation part 14 Distance data 15 Ground plane image data 16 Groove width data 17 Groove depth data 18 Groove number data 19 Evaluation area image data 20 Smoothing process image data 21 Edge process image data 22 Crack ratio data 23 Evaluation threshold data 24 Evaluation Rank Data 25 Output Data 26 Groove A Evaluation Area B Quality Evaluation Value C Groove Depth Display D Crack Degree E Groove Width Value F Groove Depth Value G Tire Width Direction Scale H Groove Depth Direction Scale

Claims

A displacement measuring unit that measures the displacement of the ground contact surface of the tire to generate distance data that enables discrimination between the ridge and the groove of the ground contact surface, and an imaging unit that captures the ground contact surface and generates the contact surface image data And an evaluation region extraction unit that generates an evaluation region image data by extracting an evaluation region for detecting a crack from a region of the groove portion on the grounding surface with reference to the distance data from the grounding surface image data, A smoothing processing unit that generates smoothed image data obtained by smoothing the evaluation area image data to remove noise, and an edge processed image in which the boundary portion of the crack is clarified by edge processing of the smoothed image data An edge detection processing unit for generating data, a deterioration evaluation unit for calculating a ratio of the edge-processed image data in the entire boundary part of the crack to generate crack ratio data, and the crack Tire degradation evaluation system and having an output unit for outputting the ratio data.
The deterioration evaluation unit generates the evaluation rank data by evaluating the ratio with predetermined evaluation threshold data for evaluating deterioration, and the output unit outputs the evaluation rank data. The tire deterioration evaluation system according to claim 1.
The displacement measuring unit calculates a groove width data by calculating a width of the groove portion of the ground contact surface of the tire from the distance data, and calculates a groove depth by calculating a depth of the groove portion from the distance data. A groove depth calculation unit for generating data, and generating groove number data related to the number of the groove portions, and the output unit is at least one of the groove width data, the groove depth data, and the groove number data. The tire deterioration evaluation system according to claim 1 or 2, wherein one piece of data is output.
The output unit simultaneously outputs the data generated by the deterioration evaluation unit and the ground plane image data generated by the imaging unit or the evaluation region image data extracted by the evaluation region extraction unit. The tire deterioration evaluation system according to any one of claims 1 to 3.
Displacement measuring step for measuring the displacement of the ground contact surface of the tire to generate distance data that enables discrimination between the crest and the groove of the ground contact surface, and an imaging step for capturing the ground contact surface and generating the contact surface image data And an evaluation area extracting step of generating an evaluation area image data by extracting an evaluation area for detecting a crack from an area of the groove on the ground plane with reference to the distance data from the ground plane image data, and A smoothing process for smoothing the evaluation area image data to remove the noise and generating a smoothed image data, and an edge-processed image in which the edge of the smoothed image data is processed to clarify the boundary between cracks Edge detection processing step for generating data, and degradation evaluation process for generating crack ratio data by calculating the ratio of the edge processed image data to the entire boundary of cracks When a tire deterioration evaluation method characterized by and an output step of outputting the crack ratio data.
In the deterioration evaluation step, the ratio is evaluated with evaluation threshold data determined in advance to evaluate deterioration, and evaluation rank data is generated, and the output step outputs the evaluation rank data. The tire deterioration evaluation method according to claim 5.
The displacement measuring step calculates a groove width data by calculating a width of the groove portion of the ground contact surface of the tire from the distance data, and calculates a groove depth by calculating a depth of the groove portion from the distance data. A groove depth calculation step for generating depth data, and generating groove portion number data relating to the number of groove portions, wherein the output step includes at least one of the groove width data, the groove depth data, and the groove portion number data. The tire deterioration evaluation method according to claim 5 or 6, wherein one piece of data is output.
The output step outputs simultaneously the data generated in the deterioration evaluation step and the ground plane image data generated in the imaging step or the evaluation region image data extracted in the evaluation region extraction step. The tire deterioration evaluation method according to any one of claims 5 to 7.
A displacement measurement step, which is a program executed for tire deterioration evaluation by a computer, and that generates a distance data that enables a discrimination between a peak portion and a groove portion of the contact surface by measuring a displacement of the contact surface of the tire. An imaging step of photographing the ground plane and generating ground plane image data; and an evaluation area for detecting cracks from the groove area on the ground plane with reference to the distance data from the ground plane image data. An evaluation region extraction step for extracting and generating evaluation region image data; a smoothing step for generating smoothed image data obtained by smoothing the evaluation region image data to remove noise; and the smoothed image Edge detection processing step for generating edge-processed image data in which the boundary of cracks is clarified by performing edge processing on the data, and cracks in the edge-processed image data Degradation evaluation step and the tire deterioration evaluation program, characterized in that to execute, an output step of outputting the crack ratio data by calculating the percentage of the total of the boundary of the record to generate a crack ratio data.