JP2023130167A - Method for evaluating turning performance of tire - Google Patents

Abstract

To provide a method capable of evaluating the turning performance, especially limit turning performance of a tire.SOLUTION: Provided is a method for evaluating the turning performance of a tire. The method includes the steps of: mounting a tire on a vehicle and causing the vehicle to make a turning travel; acquiring multiple times data of longitudinal acceleration and data of lateral acceleration generated in the vehicle during travel; creating, by a computer, a friction circle 7 by using the longitudinal acceleration data and the lateral acceleration data; calculating, by the computer, the area inside the contour 8 of the friction circle 7; and outputting, by the computer, the area.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to a method for evaluating tire turning performance.

Patent Document 1 below describes a method for evaluating the equivalent cornering power of a tire. In this method, first, a step of causing the vehicle to turn at different vehicle body speeds, a calculation step of calculating a first speed when the vehicle body slip angle becomes 0 based on the vehicle body slip angle, lateral acceleration, and vehicle body speed; An evaluation step for determining equivalent cornering power is carried out based on one speed.

Japanese Patent Application Publication No. 2018-084551

Although the above method can evaluate the steering stability performance of the tire, there is room for improvement in the evaluation of the turning performance of the tire, especially the limit turning performance.

The present disclosure was devised in view of the above-mentioned circumstances, and its main purpose is to provide a method capable of evaluating tire turning performance, particularly limit turning performance.

The present disclosure is a method for evaluating the turning performance of a tire, which includes a step of mounting the tire on a vehicle and causing the vehicle to turn, and data on longitudinal acceleration and lateral acceleration generated on the vehicle while it is running. a step in which a computer creates a friction circle using the longitudinal acceleration data and the lateral acceleration data; a step in which the computer calculates an area within the contour of the friction circle; A method for evaluating turning performance of a tire, including a step in which a computer outputs the area.

The tire turning performance evaluation method of the present disclosure makes it possible to evaluate the tire turning performance, especially the limit turning performance, by employing the above steps.

FIG. 2 is a perspective view showing a computer for executing a method for evaluating tire turning performance. It is a flowchart which shows the processing procedure of the evaluation method of the turning performance of a tire. It is a conceptual diagram of a vehicle. It is a figure showing longitudinal acceleration data and lateral acceleration data. It is a graph showing a friction circle. It is a flowchart which shows the processing procedure of an area calculation process. It is a graph showing the outline of a friction circle. It is a flowchart which shows the processing procedure of the evaluation method of the turning performance of the tire of other embodiments of this disclosure. It is a flowchart which shows an example of the processing procedure of a 1st friction circle creation process. It is a graph showing a first friction circle and a second friction circle. It is a flowchart which shows an example of the processing procedure of a 2nd friction circle creation process. It is a graph which shows the 1st outline of a 1st friction circle, and the 2nd outline of a 2nd friction circle.

Embodiments of the present disclosure will be described below based on the drawings. It should be understood that the drawings include exaggerated representations and representations that differ from actual dimensional proportions of structures to aid in understanding the disclosure. In addition, throughout each embodiment, the same or common elements are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the specific configurations shown in the embodiments and drawings are for understanding the content of the present disclosure, and the present disclosure is not limited to the specific configurations shown.

In the tire turning performance evaluation method (hereinafter sometimes simply referred to as "evaluation method") of the present embodiment, the tire turning performance, particularly the limit turning performance, is evaluated. The term "limit turning performance" refers to the turning performance near the friction limit (grip limit) that determines whether the tires will slip or not, during high-speed driving on a circuit or the like, for example. Therefore, the larger the longitudinal acceleration and lateral acceleration generated in the running vehicle, the higher the grip can be exerted, indicating that the limit turning performance is better.

[Computer]
FIG. 1 is a perspective view showing a computer 1 for executing the tire turning performance evaluation method of this embodiment. The computer 1 includes a main body 1a, a keyboard 1b, a mouse 1c, and a display device 1d. The main body 1a is provided with, for example, a processing unit (CPU), a ROM, a working memory, a storage device such as a magnetic disk, and disk drive devices 1a1 and 1a2. Further, the storage device stores in advance software and the like for executing the evaluation method of this embodiment.

[Method for evaluating tire turning performance (first embodiment)]
Next, a method for evaluating the turning performance of the tire according to the present embodiment will be explained. FIG. 2 is a flowchart showing the processing procedure of the tire turning performance evaluation method according to the present embodiment.

[Make the vehicle turn]
In the evaluation method of this embodiment, first, tires are mounted on a vehicle, and the vehicle is caused to turn (step S1). FIG. 3 is a conceptual diagram of the vehicle 2 of this embodiment.

The vehicle 2 is not particularly limited as long as the tire 3 to be evaluated can be mounted thereon. The vehicle 2 of this embodiment is a racing car. The vehicle 2 of this embodiment is provided with tires 3 to be evaluated and an acceleration sensor 4.

A known acceleration sensor may be used as the acceleration sensor 4. The acceleration sensor 4 of this embodiment may be, for example, a piezoelectric acceleration sensor that can measure acceleration in three orthogonal axes directions. The three orthogonal axes include, for example, a left-right direction X of the vehicle 2, a vertical direction Y of the vehicle 2, and a longitudinal direction Z of the vehicle 2. Such an acceleration sensor 4 makes it possible to measure longitudinal acceleration and lateral acceleration occurring in the vehicle 2 while it is running. In this embodiment, the acceleration sensor 4 is arranged at the center of gravity G of the vehicle 2, but this is not particularly limited.

The tire 3 is not particularly limited as long as its turning performance (limit turning performance) is evaluated. For example, tires 3 of various categories may be employed, such as pneumatic tires for passenger cars, motorcycles, heavy loads, racing, etc., and airless tires (non-pneumatic tires). An example of the tire 3 of this embodiment is a pneumatic tire for racing.

In step S1 of this embodiment, first, the tire 3 is assembled onto a regular rim (not shown) and filled with regular internal pressure. Then, the tires 3 filled with the normal internal pressure are mounted on all wheels of the vehicle 2. The tires 3 mounted on the vehicle 2 are loaded with a load of about 45 to 70% of the normal load, for example.

A "regular rim" is a rim defined for each tire 3 in a standard system including the standard on which the tire 3 is based. Therefore, the regular rim is, for example, a "standard rim" for JATMA, a "Design Rim" for TRA, and a "Measuring Rim" for ETRTO.

“Regular internal pressure” is the air pressure defined for each tire 3 by each standard in a standard system including the standards on which the tire 3 is based. Therefore, the normal internal pressure is, for example, the "maximum air pressure" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "INFLATION PRESSURE" for ETRTO.

The "regular load" is a load defined for each tire 3 by each standard in a standard system including the standard on which the tire 3 is based. Therefore, the normal load is, for example, "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "LOAD CAPACITY" for ETRTO.

In addition, in the case of the tire 3 for which there is no applicable standard, the rim, air pressure, and load recommended by the manufacturer are applied to the regular rim, regular internal pressure, and regular load.

Next, in step S1 of this embodiment, the vehicle 2 on which the tires 3 are mounted is caused to turn. The route for turning is not particularly limited as long as turning is possible, and for example, a circuit, a highway, a mountain road, or a general road may be adopted. In this embodiment, the vehicle 2 is running at high speed on a circuit where limit turning is possible.

[Obtain longitudinal acceleration data and lateral acceleration data]
Next, in the evaluation method of this embodiment, longitudinal acceleration data and lateral acceleration data generated in the running vehicle 2 are acquired multiple times (step S2). In step S2 of this embodiment, longitudinal acceleration data and lateral acceleration data generated in the running vehicle 2 are acquired multiple times by the acceleration sensor 4.

FIG. 4 is a diagram showing longitudinal acceleration data 5 and lateral acceleration data 6. In FIG. 4, a number (serial number), a plurality of longitudinal accelerations (longitudinal acceleration data 5), and a plurality of lateral accelerations (lateral acceleration data 6) are shown. In this embodiment, longitudinal acceleration data 5 and lateral acceleration data 6 are acquired at predetermined intervals (for example, every 100 Hz sampling frequency (that is, every 100 times/1 second (0.01 second)). . Further, the timing at which the longitudinal acceleration data 5 and the lateral acceleration data 6 are acquired is not particularly limited as long as the longitudinal acceleration data 5 and the lateral acceleration data 6 can be acquired while the vehicle 2 (shown in FIG. 3) is running at the limit turning. In this embodiment, the longitudinal acceleration data 5 and the lateral acceleration data 6 are acquired during the period from when the vehicle 2 starts traveling to when it ends (for example, one lap of the Okayama International Circuit is 3703 m).

In this embodiment, in order to reliably acquire longitudinal acceleration data 5 and lateral acceleration data 6 during limit turning, for example, in a circuit, the vehicle 2 (Fig. 3 ) is preferably run. In order to be able to drive at such limits, it is preferable that the vehicle be driven by a driver who has trained in advance on a circuit or the like. This makes it possible to reliably evaluate the limit turning performance. The longitudinal acceleration data 5 and the lateral acceleration data 6 are stored in the computer 1 (shown in FIG. 1).

[Create friction circle]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) creates a friction circle using the longitudinal acceleration data 5 and the lateral acceleration data 6 (step S3). FIG. 5 is a graph showing the friction circle 7. In FIG. 5, the vertical axis shows longitudinal acceleration, and the horizontal axis shows lateral acceleration.

On the vertical axis of FIG. 5, the higher it goes above 0, the greater the acceleration in the front direction (during driving), and the more it goes below 0, the more acceleration in the rear direction (during braking). It shows that is large. On the other hand, on the horizontal axis of FIG. This shows that the acceleration is large.

In step S3 of this embodiment, longitudinal acceleration data 5 and lateral acceleration data 6 (longitudinal acceleration and lateral acceleration) shown in FIG. 4 are plotted on the vertical and horizontal axes of FIG. 5, respectively. As a result, a friction circle 7 is created from a collection of plotted points. In the friction circle 7, the darkly colored portion indicates that the frequency of acceleration (longitudinal acceleration and lateral acceleration) occurring in the running vehicle 2 is high.

The friction circle 7 can be created as appropriate. For example, by importing the longitudinal acceleration data 5 and the lateral acceleration data 6 into known spreadsheet software (for example, Excel ("Excel" is a registered trademark)), and using the graph creation function of the spreadsheet software, the friction circle 7 can be calculated. Can be easily created. In order to efficiently create such a friction circle 7, it is preferable to create it automatically using, for example, a macro (automation function) of spreadsheet software. This makes it possible to create the friction circle 7 accurately in a short time. The friction circle 7 is input into the computer 1 (shown in FIG. 1).

[Calculate the area of the friction circle (area calculation process)]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) calculates the area within the contour of the friction circle 7 (area calculation step S4). The area within the contour of the friction circle 7 can be calculated as appropriate. FIG. 6 is a flowchart showing the processing procedure of the area calculation step S4.

[Extract contour]
In the area calculation step S4 of this embodiment, the computer 1 (shown in FIG. 1) first performs image processing on the friction circle 7 shown in FIG. 5 to extract a contour (step S41). Image processing can be performed as appropriate as long as the outline of the friction circle 7 can be extracted.

In step S41 of this embodiment, first, the friction circle 7 is converted into image information. Next, the color information (pixels) indicated by the image information of the friction circle 7 is subjected to image processing such as binarization processing, for example, based on a predetermined threshold value. The friction circle 7 (not shown) after such image processing is composed only of accelerations with high frequency (that is, accelerations shown in dark colors), and measurement noise (accelerations with low frequency) is eliminated. There is.

FIG. 7 is a graph showing the contour 8 of the friction circle 7. Next, in step S41 of this embodiment, the contour 8 of the friction circle 7 (not shown) acquired by image processing is extracted. Such a contour 8 shows the range of accelerations experienced by the moving vehicle (ie accelerations from which measurement noise has been eliminated by image processing). The contour 8 of the friction circle is stored in the computer 1 (shown in FIG. 1).

[Calculate area within contour]
Next, in the area calculation step S4 of this embodiment, the computer 1 (shown in FIG. 1) calculates the area within the contour 8 of the friction circle 7 (step S42). The area within the contour 8 can be calculated as appropriate. In step S42 of this embodiment, first, an area 9 surrounded by the outline 8 is specified from the coordinate values of the outline 8. Then, the specified region is divided into minute sections (not shown), and the area within the contour 8 is calculated by summing (ie, integrating) the areas of these minute sections. In this embodiment, the area is calculated when 1.0G is converted to 1.0m.

Preferably, the area within the contour 8 of the friction circle 7 is automatically calculated using, for example, a macro (automation function) of spreadsheet software. This allows the area within the contour 8 to be calculated accurately in a short time. The area within the contour 8 is stored in the computer 1 (shown in Figure 1).

[Output area of friction circle]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) outputs the area within the contour 8 of the friction circle 7 (step S5). In step S5 of this embodiment, the area within the contour 8 of the friction circle 7 (shown in FIG. 7) is output from the display device 1d of the computer 1 shown in FIG. 1, a printer (not shown), or the like. The area may be output together with the friction circle 7, as shown in FIG.

The larger the area of the contour 8 of the friction circle 7 is, the more the longitudinal acceleration data 5 and the lateral acceleration data 6 are distributed in a range of large longitudinal acceleration and lateral acceleration. Therefore, the larger the area of the contour 8 is, the higher the friction limit (grip limit) of the tire 3 (shown in FIG. 3) is, indicating that the limit turning performance is excellent.

On the other hand, the smaller the area of the contour 8 of the friction circle 7 is, the more the longitudinal acceleration data 5 and the lateral acceleration data 6 are distributed in a range of small longitudinal acceleration and lateral acceleration. Therefore, the smaller the area of the contour 8, the smaller the friction limit (grip limit) of the tire 3 (shown in FIG. 3), which indicates that the limit turning performance is inferior.

In this embodiment, by outputting the area within the contour 8 of the friction circle 7, it becomes possible to evaluate the turning performance (limit turning performance) of the tire 3 to be evaluated based on the size of the area. .

[Evaluate turning performance]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) evaluates the turning performance of the tire 3 (shown in FIG. 3) based on the area within the contour 8 of the friction circle 7 shown in FIG. (Step S6). The evaluation of turning performance (limit turning performance) is performed as appropriate if it is based on the area within the contour 8.

As mentioned above, the larger the area within the contour 8 of the friction circle 7, the better the turning performance (limit turning performance), while the smaller the area of the contour 8, the worse the limit turning performance. There is. In the present embodiment, the turning performance (limit turning performance) of the tire 3 (shown in FIG. 3) is evaluated to be good when the area of the contour 8 is equal to or larger than a predetermined threshold value. The threshold value can be set as appropriate depending on the turning performance required of the tire 3 to be evaluated.

In step S6, if it is determined that the turning performance (limit turning performance) of the tire 3 shown in FIG. (Produced) (Process S7). On the other hand, in step S6, if it is determined that the turning performance (limit turning performance) of the tire 3 is poor ("No" in step S6), the design factors of the tire 3 are changed and the tire 3 is prototyped (step S6). S8), steps S1 to S6 are performed again. This makes it possible to reliably design and manufacture (produce) a tire 3 with good turning performance (limit turning performance).

[Method for evaluating tire turning performance (second embodiment)]
In the evaluation method of the embodiments described above, the friction circle 7 of one tire 3 to be evaluated is created, but the invention is not limited to this embodiment. For example, a plurality of tire friction circles 7 may be created.

In the evaluation method of this embodiment, a case is exemplified in which friction circles are created for a first tire 3A and a second tire 3B (shown in FIG. 3). The first tire 3A and the second tire 3B differ from each other in at least some of the design factors. FIG. 8 is a flowchart showing a processing procedure of a method for evaluating tire turning performance according to another embodiment of the present disclosure.

[Create the first friction circle]
In the evaluation method of this embodiment, first, the computer 1 (shown in FIG. 1) creates a first friction circle that is a friction circle of the first tire 3A (first friction circle creation step S11). FIG. 9 is a flowchart showing an example of the processing procedure of the first friction circle creation step S11.

In the first friction circle creation step S11 of this embodiment, first, as shown in FIG. 3, a step S111 is performed in which the first tires 3A are mounted on the vehicle 2 and the vehicle 2 is caused to turn. Next, step S112 is performed in which longitudinal acceleration data 5 and lateral acceleration data 6 (shown in FIG. 3) generated during driving are acquired multiple times for the vehicle 2 equipped with the first tires 3A. Next, a step S113 is performed in which the computer 1 (shown in FIG. 1) creates a first friction circle using the longitudinal acceleration data 5 and the lateral acceleration data 6 of the first tire 3A. These steps S111 to S113 are performed based on the same procedure as steps S1 to S3 (shown in FIG. 2) of the previous embodiments. FIG. 10 is a graph showing the first friction circle 7A and the second friction circle 7B.

[Create second friction circle]
In the evaluation method of this embodiment, first, the computer 1 (shown in FIG. 1) creates a second friction circle 7B (shown in FIG. 10), which is a friction circle of the second tire 3B (second friction circle creation step). S12). FIG. 11 is a flowchart showing an example of the processing procedure of the second friction circle creation step S12.

In the second friction circle creation step S12 of this embodiment, first, as shown in FIG. 3, a step S121 is performed in which the second tires 3B are mounted on the vehicle 2 and the vehicle 2 is caused to turn. Next, step S122 is performed in which longitudinal acceleration data 5 and lateral acceleration data 6 (shown in FIG. 4) generated during driving are acquired multiple times for the vehicle 2 equipped with the second tires 3B. Next, a step S123 is performed in which the computer 1 (shown in FIG. 1) creates a second friction circle 7B (shown in FIG. 10) using the longitudinal acceleration data 5 and lateral acceleration data 6 of the second tire 3B. These steps S121 to S123 are performed based on the same procedure as steps S1 to S3 (shown in FIG. 2) of the previous embodiments.

[Outputs a graph that overlaps the first friction circle and the second friction circle]
Next, in the evaluation method of this embodiment, as shown in FIG. 10, the computer 1 (shown in FIG. 1) makes it possible to determine the difference between the first friction circle 7A and the second friction circle 7B. A graph in which the first friction circle 7A and the second friction circle 7B are overlapped is output (step S13). In this embodiment, a difference is made in the contrast between the first friction circle 7A and the second friction circle 7B. For example, the first friction circle 7A is displayed brightly, and the second friction circle 7B is displayed darkly. There is. Thereby, it becomes possible to easily distinguish between the first friction circle 7A and the second friction circle 7B.

In the evaluation method of this embodiment, by overlapping the first friction circle 7A and the second friction circle 7B, it is possible to directly compare the size of the first friction circle 7A and the size of the second friction circle 7B. . Thereby, the difference in turning performance (limit turning performance) between the first tire 3A and the second tire 3B (shown in FIG. 3) can be easily visually confirmed. Furthermore, the respective magnitudes of longitudinal acceleration and lateral acceleration can be compared between the first tire 3A and the second tire 3B. Therefore, in the evaluation method of this embodiment, the turning performance (limit turning performance) of the first tire 3A and the second tire 3B can be evaluated.

In step S111 (shown in FIG. 9) and step S121 (shown in FIG. 11) of causing the vehicle 2 to turn, the vehicle 2 (shown in FIG. 3) equipped with the first tire 3A and the vehicle equipped with the second tire 3B are 2 (shown in FIG. 3) on the same circuit. In this step, longitudinal acceleration data 5 and lateral acceleration data 6 (shown in FIG. 4) are acquired for the first tire 3A and the second tire 3B, respectively. As a result, the first friction circle 7A and the second friction circle 7B are created based on the longitudinal acceleration data 5 and the lateral acceleration data 6 acquired under the same conditions, so that the first tire 3A and the second tire 3B are It becomes possible to evaluate turning performance (limit turning performance) with high accuracy.

[Calculate the area of the first friction circle and the second friction circle]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) calculates the area within the first contour of the first friction circle 7A and the area within the second contour of the second friction circle 7B. (Step S14). FIG. 12 is a graph showing a first contour 8A of the first friction circle 7A and a second contour 8B of the second friction circle 7B. In step S14 of this embodiment, the area within the first contour 8A and the area within the second contour 8B are calculated based on the same processing procedure as the area calculation step S4 (shown in FIGS. 2 and 6) of the previous embodiments. The area within each is calculated. The calculated area within the first contour 8A and the area within the second contour 8B are stored in the computer 1 (shown in FIG. 1).

[Output the area of the first friction circle and the second friction circle]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) calculates the area within the first contour 8A of the first friction circle 7A and the area within the second contour 8B of the second friction circle 7B. is output (step S15). Step S15 is based on the same procedure as step S5 (shown in FIG. 2) of outputting the area of the previous embodiments, and calculates the area of the first friction circle 7A (first tire 3A) as shown in FIG. The area and the area of the second friction circle 7B (second tire 3B) are each output.

In this embodiment, the area within the first contour 8A of the first friction circle 7A and the area within the second contour 8B of the second friction circle 7B are output, so that the area between the first friction circle 7A and the second contour 8B is output. It is possible to compare not only the visual difference from the friction circle 7B but also the size of each area. Therefore, in the evaluation method of this embodiment, it is possible to compare the difference in turning performance (limit turning performance) between the first tire 3A and the second tire 3B. Further, as shown in FIG. 12, the area of the first friction circle 7A (first tire 3A) and the area of the second friction circle 7B (second tire 3B) may be displayed in descending order. Alternatively, the ranking may be displayed. Thereby, it becomes possible to accurately evaluate the turning performance of the first tire 3A and the turning performance of the second tire 3B.

[Evaluate turning performance]
Next, in the evaluation method of this embodiment, the computer 1 (shown in FIG. 1) calculates the area within the first contour 8A of the first friction circle 7A and the area within the second contour 8B of the second friction circle 7B. Based on this, the turning performance of the first tire 3A and the turning performance of the second tire 3B are evaluated (step S16). The evaluation of the turning performance (limit turning performance) is carried out as appropriate as long as it is based on the areas of the first friction circle 7A and the second friction circle 7B.

In step S16, if the area within the first contour 8A of the first friction circle 7A is larger than the area within the second contour 8B of the second friction circle 7B, the first tire 3A is larger than the second tire 3B. The turning performance (limit turning performance) is evaluated to be good ("first tire" in step S16). In this case, the first tire 3A is manufactured (produced) based on the design factors of the first tire 3A (step S17).

On the other hand, in step S16, if the area within the second contour 8B of the second friction circle 7B is larger than the area within the first contour 8A of the first friction circle 7A, the second tire 3B is ("second tire" in step S16). In this case, the second tire 3B is manufactured (produced) based on the design factors of the second tire 3B (step S18).

In this manner, in this embodiment, it is possible to reliably design and manufacture (produce) the tire 3 with good tire turning performance (limit turning performance) among the first tire 3A and the second tire 3B. Become. Note that if the area of the first friction circle 7A and the area of the second friction circle 7B are the same, or if the area of the friction circle is less than a predetermined threshold, the first tire 3A and the second tire The design factors of 2B may be changed and the first friction circle creation step S11 to step S16 may be performed again.

In this embodiment, as shown in FIG. 12, a graph in which the first friction circle 7A of the first tire 3A and the second friction circle 7B of the second tire 3B are overlapped is output. but not limited to. For example, friction circles (not shown) of a plurality of tires 3 (such as a third tire) different from the first tire 3A and the second tire 3B may be overlapped. This makes it possible to evaluate the turning performance (limit turning performance) of a plurality of tires 3.

In this embodiment, the first friction circle 7A of the first tire 3A and the second friction circle 7B of the second tire 3B are compared, but the invention is not limited to such an aspect. For example, a friction circle (not shown) when running on a first road surface with tires 3 is compared with a friction circle (not shown) when running on tires 3 on a second road surface different from the first road surface. It's okay. This makes it possible to evaluate the turning performance of the tire 3 exhibited on different road surfaces.

Although particularly preferred embodiments of the present disclosure have been described above in detail, the present disclosure is not limited to the illustrated embodiments, and can be modified and implemented in various ways.

[Additional notes]
The present disclosure includes the following aspects.

[This disclosure 1]
A method for evaluating turning performance of a tire, the method comprising:
a step of mounting the tire on a vehicle and causing the vehicle to turn;
a step of acquiring longitudinal acceleration data and lateral acceleration data occurring in the running vehicle multiple times;
a step in which the computer creates a friction circle using the longitudinal acceleration data and the lateral acceleration data;
the computer calculating an area within the contour of the friction circle;
the computer outputting the area;
A method for evaluating tire turning performance.
[This disclosure 2]
The method for evaluating the turning performance of a tire according to the present disclosure 1, further comprising a step of the computer evaluating the turning performance of the tire based on the area.
[Disclosure 3]
The method for evaluating the turning performance of a tire according to the present disclosure 2, wherein the step of evaluating includes a step of evaluating the turning performance as being better as the area is larger.
[Disclosure 4]
The method for evaluating turning performance of a tire according to any one of the present disclosures 1 to 3, wherein the step of calculating the area includes the step of extracting the contour by image processing the friction circle.
[This disclosure 5]
the computer creating a first friction circle that is a friction circle of a first tire;
the computer creating a second friction circle that is a friction circle of a second tire;
The computer outputs a graph in which the first friction circle and the second friction circle are overlapped so that a difference between the first friction circle and the second friction circle can be determined. A method for evaluating turning performance of a tire according to any one of Disclosures 1 to 4.
[This disclosure 6]
The present disclosure 5 includes the step of driving a vehicle equipped with the first tire and a vehicle equipped with the second tire on the same circuit to obtain the longitudinal acceleration data and the lateral acceleration data, respectively. Method for evaluating the turning performance of the tires described.

7 Friction circle 8 Contour

Claims (6)

A method for evaluating turning performance of a tire, the method comprising:
a step of mounting the tire on a vehicle and causing the vehicle to turn;
a step of acquiring longitudinal acceleration data and lateral acceleration data occurring in the running vehicle multiple times;
a step in which the computer creates a friction circle using the longitudinal acceleration data and the lateral acceleration data;
the computer calculating an area within the contour of the friction circle;
the computer outputting the area;
A method for evaluating tire turning performance. The method for evaluating the turning performance of a tire according to claim 1, further comprising the step of: the computer evaluating the turning performance of the tire based on the area. The method for evaluating turning performance of a tire according to claim 2, wherein the step of evaluating includes a step of evaluating the turning performance as being better as the area is larger. The method for evaluating turning performance of a tire according to any one of claims 1 to 3, wherein the step of calculating the area includes the step of extracting the contour by image processing the friction circle. the computer creating a first friction circle that is a friction circle of a first tire;
the computer creating a second friction circle that is a friction circle of a second tire;
The computer outputs a graph in which the first friction circle and the second friction circle are overlapped so that a difference between the first friction circle and the second friction circle can be determined. A method for evaluating turning performance of a tire according to any one of Items 1 to 4. 6. The method according to claim 5, further comprising the step of driving a vehicle equipped with the first tire and a vehicle equipped with the second tire on the same circuit to obtain the longitudinal acceleration data and the lateral acceleration data, respectively. Method for evaluating the turning performance of the tires described.

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