JP6387793B2 - Tire characteristic calculation method and tire characteristic calculation apparatus - Google Patents

Description

  The present invention relates to a tire characteristic calculation method and a tire characteristic calculation apparatus that calculate tire characteristics.

  As an index of steering stability of a pneumatic tire (hereinafter simply referred to as a tire) that affects the steering stability of the vehicle, there is a lateral spring constant of the tire. As the tire has a higher lateral spring constant, the tire is more difficult to deform with respect to the lateral force, so that a greater lateral force can be exerted without a large time delay. With such tire characteristics, both the longitudinal spring constant and the tire are in a static state, that is, in a non-rotating state, one place on the tire circumference is grounded to the road surface and a predetermined load is applied to the tire to ground the tire. . At this time, a lateral force acting on the tire or road surface is measured by applying a relative lateral displacement (tire width direction) between the grounded tire and the road surface.

On the other hand, a tire performance measurement system capable of measuring a spring constant of a pneumatic tire in a situation close to an actual use state is known (Patent Document 1).
Specifically, in the tire performance measurement system, a test machine that rotates a tire on the ground contact surface, a condition setting unit that sets test conditions on the test device, and the tire and the ground contact surface are relatively moved. The spring constant of the tire is calculated based on the deformation measurement unit that measures at least a part of deformation on the circumference of the tire, the deformation detected by the deformation measurement unit, and the test conditions set by the condition setting unit. A spring constant calculating unit.

JP 2011-237258 A

  However, since the tire performance measurement system requires an imaging device and an illumination lamp for measuring deformation of the rotating tire, it is difficult to easily calculate the tire spring constant.

  Therefore, the present invention provides a tire characteristic calculation method and a tire characteristic that can calculate the lateral spring constant of a rolling tire more easily than a conventional method by using a method different from the conventional tire performance measurement system. An object is to provide a calculation device.

One aspect of the present invention is a tire characteristic calculation method for calculating tire characteristics using a computer. The tire characteristic calculation method is as follows:
Data on the separation distance with slip angle between the tire rotation axis and the road surface, and data on the lateral force of the tire in a condition where the tire is rolled by applying a slip angle to the road surface on the road surface, A step in which the computer obtains,
The computer uses the data of the separation distance with the slip angle and the data of the 0 degree separation distance between the rotating shaft and the road surface during rolling of the tire when the slip angle is 0 degree, Calculating a virtual lateral displacement amount in which the tire is virtually laterally displaced on the road surface;
The computer has a step of calculating a lateral spring constant of the rolling tire using the lateral force data and the virtual lateral displacement amount.

  In the step of calculating the virtual lateral displacement amount, it is preferable that a square root of a difference obtained by subtracting a square of the data of the separation distance with slip angle from the square of the data of the 0 degree separation distance is set as the virtual lateral displacement amount.

  In the step of calculating the virtual lateral displacement, the 0 value is obtained from the first value obtained by multiplying the 0 degree separation distance data by ε (ε is a constant greater than 0 and less than 1), and the slip angle separation distance data. A second value obtained by subtracting (1−ε) times the value of the distance data is obtained, and the square root of the difference obtained by subtracting the square of the second value from the square of the first value is It is also preferable to use the virtual lateral displacement amount.

  The computer acquires tire slip distance data and tire lateral force data under a plurality of conditions in which the slip angle is changed by a plurality of values, and the slip angle in each condition. By obtaining a relationship between the virtual lateral displacement amount and the lateral force data, and calculating a gradient with respect to the virtual lateral displacement amount of the lateral force data when the virtual lateral displacement amount becomes 0 from the relationship, It is preferable to calculate the lateral spring constant of the rolling tire.

  The plurality of conditions of the slip angle preferably include an angle greater than 0 degree and an angle less than 0 degree.

  The slip distance-separated distance data used for calculating the virtual lateral displacement amount is obtained when the lateral force data is equal to or less than half of a vertical load when the tire is brought into contact with the road surface to roll the tire. It is preferably data.

Yet another embodiment of the present invention is a tire characteristic calculation device that calculates tire characteristics. The tire characteristic calculation device
Data on the separation distance with a slip angle between the rotation axis of the tire and the road surface, and data on the lateral force of the tire in a condition in which the tire is rolled by applying a slip angle to the road surface on the road surface, A data acquisition unit for acquiring
The tire on the road surface using the slip distance separation data and the 0 degree separation data between the rotating shaft and the road surface during rolling of the tire when the slip angle is 0 degrees. A first arithmetic unit that calculates a virtual lateral displacement amount that is virtually laterally displaced;
A second computing unit that calculates a lateral spring constant of the rolling tire by using the lateral force data and the virtual lateral displacement amount;

  It is preferable that the first calculating unit sets a square root of a difference obtained by subtracting a square of the data of the separation distance with slip angle from a square of the data of the 0 degree separation distance as the virtual lateral displacement amount.

  The first computing unit calculates the 0 degree separation distance from the first value obtained by ε times the constant of the 0 degree separation data (ε is a constant greater than 0 and less than 1) and the separation data with the slip angle. A second value obtained by subtracting a value obtained by multiplying the data of (1−ε) by a value obtained by subtracting the square of the second value from the square of the first value, and calculating the square root of the difference. It is preferable to use an amount.

  According to the tire characteristic calculation method and the tire characteristic calculation device described above, the lateral spring constant of the rolling tire can be calculated more easily than in the conventional method.

(A), (b) is a figure explaining the tire in rolling which added slip angle (alpha). It is a figure explaining an example with respect to the slip angle (alpha) of the tire of the separation distance Z ((alpha)) between a tire rotating shaft and a road surface. (A), (b) is a figure explaining an example of the calculation method of virtual lateral displacement amount (DELTA) y ((alpha)) of this embodiment. It is a figure explaining the composition of the tire characteristic calculation device of this embodiment. It is a figure which shows an example of the change with respect to virtual lateral displacement amount (DELTA) y ((alpha)) of lateral force Fy ((alpha)). It is a figure explaining the flow of the tire characteristic calculation method of this embodiment. It is a figure explaining the other example of the calculation method of virtual lateral displacement amount (DELTA) y ((alpha)) of this embodiment. (A)-(c) is a figure explaining other calculation methods different from the calculation method shown in FIG. It is a figure which compares the lateral spring constant calculated | required with the method of this embodiment, and the lateral spring constant obtained by the conventional measuring method. (A), (b) is a figure which shows the correspondence of a lateral spring constant.

  Hereinafter, a tire characteristic calculation method and a tire characteristic calculation apparatus of the present invention will be described in detail with reference to the accompanying drawings.

(Summary of calculation of transverse spring constant)
FIGS. 1A and 1B are diagrams for explaining a rolling tire to which a slip angle α is added. In the present embodiment, it is assumed that the camber angle is 0 degree. The slip angle α is an inclination angle on the road surface between a plane perpendicular to the rotation axis of the tire and a plane perpendicular to the road surface including the relative movement direction of the tire and the road surface. The tire 10 travels on the road surface 12 under the measurement conditions of the load Fz and the travel speed V. Further, the tire 10 is given a slip angle α. At this time, the lateral force Fy acting on the tire rotation shaft 14 of the tire 10 is measured. Thus, a well-known testing machine can be used as a tire testing machine that measures the lateral force Fy under the conditions of the load load Fz, the traveling speed V, and the slip angle α. Examples of the tire testing machine include a belt type tire testing machine having a belt surface as a road surface and a drum type tire testing machine having a drum surface as a road surface. In this embodiment, when the lateral force Fy is measured by giving the slip angle α, the separation distance Z (α) with the slip angle between the tire rotation shaft 14 of the tire 10 and the road surface 12 is acquired. Z (α) can also be measured by a displacement meter incorporated in the tire testing machine.

  FIG. 2 is a view for explaining an example of a change in the slip angle-separated distance Z (α) with respect to the slip angle α of the tire 10. As shown in FIG. 2, the slip distance with a slip angle Z (α) decreases as the slip angle α increases. In FIG. 3, regardless of the positive slip angle α or the negative slip angle α, the larger the absolute value of the slip angle α, the smaller the separation distance Z (α) with the slip angle. As described above, the separation distance Z (α) with the slip angle becomes smaller as the absolute value of the slip angle α increases. The slip angle α is given to the tire 10 so that the side portion of the tire 10 becomes lateral. This is because the amount of vertical deflection changes according to the deformation. Therefore, the slip angled separation distance Z (α) including information on the amount of vertical deflection of the tire 10 includes information on the amount of lateral displacement deformed in the lateral shape of the side of the tire 10. In the present embodiment, information on the lateral displacement amount, that is, the virtual lateral displacement amount of the tire 10 at the slip angle α, the separation distance Z (α) with a slip angle and the 0 degree separation distance Z (0) at a slip angle of 0 degree. Can be used to calculate.

FIGS. 3A and 3B are schematic views for explaining that the tire 10 is laterally deformed by being given a slip angle α. The tire 10 is given a slip angle α from a state where the slip angle is 0 degrees, and the side portion is deformed in the lateral direction. In accordance with the lateral deformation 16, the slip angled separation distance Z (α) changes to a value different from the 0 degree slip angle separation distance Z (0).
Therefore, the lateral deformation 16 of the side portion shown in FIG. 3A can be schematically represented as shown in FIG. That is, as shown in FIG. 3B, the virtual lateral displacement amount Δy (α) in the lateral deformation 16 can be expressed as the length of the base of the right triangle shown in FIG. Therefore, as shown in FIG. 3 (b), the virtual lateral displacement amount Δy (α) according to the three-square theorem of a right triangle using the slip angled separation distance Z (α) and the 0 degree separation distance Z (0). ) Can be calculated.
In the present embodiment, the lateral spring constant of the rolling tire is calculated using the virtual lateral displacement amount Δy (α) and the lateral force measurement result.

(Tire characteristic calculation device)
FIG. 4 is a diagram illustrating the configuration of the tire characteristic calculation device 20 that calculates the lateral spring constant Ky of the present embodiment. The tire characteristic calculation device 20 is configured by a computer. The data acquisition part 22, the 1st calculating part 24, and the 2nd calculating part 26 are formed by starting the program memorize | stored in the memory which is not shown in figure of a computer. That is, the data acquisition unit 22, the first calculation unit 24, and the second calculation unit 26 are software modules formed by starting a program. Therefore, the operations of the data acquisition unit 22, the first calculation unit 24, and the second calculation unit 26 are substantially governed by a CPU (not shown) of the computer.

  The data acquisition unit 22 measures and outputs the above-described tire testing machine, the 0-degree separation distance Z (0) with a slip angle of 0 degrees, the separation distance with slip angle Z (α) at the slip angle α, and the lateral force. Data on Fy (α), slip angle α and load load Fz, which are measurement conditions, is acquired.

  The first calculation unit 24 uses the slip distance with a slip angle Z (α) and the 0 degree separation distance Z (0) to calculate a virtual lateral displacement amount Δy that the tire 10 virtually laterally displaces on the road surface 12. (Α) is calculated. The virtual lateral displacement amount Δy (α) is preferably calculated using, for example, the method shown in FIG. In this case, specifically, the square root of the difference obtained by subtracting the square of the separation distance with slip angle Z (α) from the square of the 0 degree separation distance Z (0) is defined as a virtual lateral displacement amount Δy (α).

  The second calculation unit 26 calculates the lateral spring constant of the rolling tire 10 using the lateral force Fy (α) and the virtual lateral displacement amount Δy (α). The calculated lateral spring constant is sent to an output device 30 such as a printer or a display. The calculation method of the lateral spring constant is not particularly limited, but the virtual lateral displacement amount Δy (α) is calculated from the inter-axis distance Z (α) with slip angle at the slip angle α. Under the condition of the slip angle α, the lateral displacement amount of the tread portion with respect to the road surface gradually increases from the stepping end where the tread portion of the tire 10 starts to contact the road surface 12 to the kicking end where the contact with the road surface 12 ends and leaves. Become bigger. That is, at the slip angle α, the lateral displacement amount is not constant within the contact surface of the tire 10 that contacts the road surface 12. For this reason, when calculating the lateral spring constant, the virtual lateral displacement amount Δy (α) is preferably obtained under a small condition, and the result of dividing the lateral force Fy (α) by this small virtual lateral displacement amount Δy (α) is obtained. The lateral spring constant can be set. In particular, it is preferable to obtain the lateral spring constant Ky by obtaining the change (gradient) of the lateral force Fy (α) with respect to the virtual lateral displacement amount Δy (α) when the slip angle α is extremely close to zero.

  Specifically, the data acquisition unit 22 performs the separation distance Z (α) with the slip angle of the tire and the lateral force Fy (α) of the tire 10 under a plurality of measurement conditions in which the slip angle α is changed with a plurality of values. And get. The first calculation unit 24 obtains the relationship between the virtual lateral displacement amount Δy (α) and the lateral force Fy (α) under each measurement condition of the slip angle α. At this time, the second calculation unit 26 calculates the gradient of the lateral force Fy (α) with respect to the virtual lateral displacement amount Δy (α) when the virtual lateral displacement amount Δy (α) becomes 0 from the obtained relationship. Thus, the lateral spring constant Ky of the rolling tire 10 is calculated.

  FIG. 5 is a diagram illustrating an example of a change in the lateral force Fy (α) with respect to the virtual lateral displacement amount Δy (α). As shown in FIG. 5, the lateral force Fy (α) increases as the absolute value of the virtual lateral displacement amount Δy (α) increases. Using this relationship, the second calculation unit 26 can calculate the gradient of the lateral force Fy (α) when the virtual lateral displacement amount Δy (α) is 0, and can use this gradient as the lateral spring constant Ky. For example, the data plotted in FIG. 5 is subjected to linear regression or curve regression, and the lateral force Fy (α) when the virtual lateral displacement amount Δy (α) is 0 is obtained by using the linear equation or the curve equation obtained thereby. The slope can be calculated.

(Tire characteristics calculation method)
FIG. 6 is a diagram illustrating an example of a flow of the tire characteristic calculation method of the present embodiment.
First, the data acquisition unit 22 acquires the slip angle-added separation distance Z (α) and the lateral force Fy (α) of the tire 10 under the condition that the tire 10 is rolled by applying the slip angle α to the tire 10. (Step S10). At this time, data of the 0 degree separation distance Z (0), the slip angle α and the load Fz, which are measurement conditions, are also acquired by the data acquisition unit 22 (step S10).

  Next, a virtual lateral displacement amount in which the tire 10 virtually laterally displaces with respect to the road surface 12 using the slip angle-equipped separation distance Z (α) and the 0-degree separation distance Z (0) at the slip angle of 0 degrees. Δy (α) is calculated by the first calculation unit 24 (step S12). At this time, as shown in FIG. 3 (b), according to the geometric limitation of the right triangle of Z (α), Z (0), and Δy (α), the slip from the square of the zero degree separation distance Z (0) The square root of the difference obtained by subtracting the square of the data of the angular separation distance Z (α) is preferably set as the virtual lateral displacement amount Δy (α). Thereby, the virtual lateral displacement amount Δy (α) used for calculating the lateral spring constant Ky can be easily calculated.

  It is also preferable to use a method as shown in FIG. 7 instead of the calculation method of the virtual lateral displacement amount Δy (α). The method shown in FIG. 7 assumes that lateral deformation is extremely small near the bead portion of the side portion of the tire 10 and that only a portion near the tread portion of the side portion near the 0-degree separation distance Z (0) is laterally deformed. Yes. Therefore, the method shown in FIG. 7 is preferably applied to a wide tire or a tire having a low flatness. In this case, as shown in FIG. 7, of the 0 degree separation distance Z (0), only the portion on the outer side in the tire radial direction that contacts the road surface 12, that is, the part ε times the 0 degree separation distance Z (0) is lateral. It is preferable to calculate the virtual lateral displacement amount Δy (α) according to the right-angled triangular lateral deformation 18 shown in FIG. That is, the first value obtained by ε times the 0-degree separation distance Z (0) (ε is a constant greater than 0 and less than 1), and (1) A second value obtained by subtracting the value multiplied by -ε) is obtained by the first calculation unit 24. And in the 1st calculating part 24, the square root of the difference which deducted the square of the 2nd value calculated | required from the square of the calculated | required 1st value is made into a virtual lateral displacement amount.

  Further, instead of calculating the virtual displacement amount Δy (α) shown in FIG. 7, the lateral deformation 18 is not linearly deformed like the hypotenuse of a right triangle, but is laterally displaced as shown in FIG. Alternatively, the lateral deformation 18 may be a curved shape that is rounded in the opposite direction (leftward in FIG. 8A). 8A to 8C are diagrams for explaining still another calculation method different from the calculation method shown in FIG. The curved lateral deformation 18 as shown in FIG. 8A is a shape that approximates the deformation shape of the side portion of the tire that has undergone lateral displacement. In this case as well, in the same way as the calculation method shown in FIG. 7, it is assumed that deformation occurs in the lower part (outer side in the tire radial direction) in FIG. 8A than the position (1-ε) · Z (0). Yes. As shown in FIG. 8B, when the curved shape of the lateral deformation 18 is expressed as a curve y = Fy (α) · λ (Z), the curve defined on the right side of the equation shown in FIG. Find Zα such that the along peripheral length is ε · Z (0). The position in the y direction in Zα, that is, Fy (α) · λ (Zα) is the virtual lateral displacement amount Δy (α). Thus, the virtual lateral displacement amount Δy (α) can be calculated by representing the lateral deformation 18 in a curved shape. Note that λ (Z) can be expressed by a Z polynomial, an exponential function, or the like.

  Such virtual lateral displacement amount Δy (α) is obtained under a plurality of conditions with different slip angles α. Specifically, the separation distance Z (α) with the slip angle of the tire 10 and the lateral force Fy (α) of the tire 10 are acquired under a plurality of conditions in which the slip angle α is changed with a plurality of values. Then, the first calculation unit 24 obtains the relationship between the virtual lateral displacement amount Δy (α) and the lateral force Fy (α) under each condition of the slip angle α as shown in FIG. 5 (step S14).

  Thereafter, from the relationship obtained in step S14, the second computing unit 26 determines the gradient of the lateral force Fy (α) with respect to the virtual lateral displacement amount Δy (α) when the virtual lateral displacement amount Δy (α) becomes zero. Is calculated. This gradient is set as the lateral spring constant Ky (step S16). For example, the relationship shown in FIG. 5 is subjected to linear regression or curve regression, and the lateral force Fy (when the virtual lateral displacement amount Δy (α) becomes 0 using the linear equation or the curved equation obtained thereby. It is preferable to calculate the slope of α).

  Thus, in the present embodiment, the lateral spring constant Ky of the rolling tire 10 when the slip angle α is given can be calculated by calculating the virtual lateral displacement amount Δy (α). The virtual lateral displacement amount Δy (α) is a separation distance Z (α) with a slip angle and a 0 degree separation distance between the tire rotation shaft 14 and the road surface 12 without imaging the lateral deformation shape of the side portion of the tire 10. It can be calculated using Z (0). Therefore, in the present embodiment, the lateral spring constant of the rolling tire can be easily calculated by a method different from the conventional method as compared with the conventional method.

At this time, the slip angle α is given to the tire 10 under a condition of a plurality of slip angles. The slip angle α includes an angle larger than 0 degree and an angle smaller than 0 degree, so that a more accurate lateral spring constant is obtained. This is preferable from the viewpoint of obtaining Ky.
Also, the slip angled separation distance Z (α) used for calculating the virtual lateral displacement amount Δy (α) is vertical when the lateral force Fy (α) contacts the road surface 12 to roll the tire 10. It is preferable to calculate the virtual lateral displacement amount Δy (α) when the data is equal to or less than half the load load Fz that is a load. When the lateral force Fy (α) exceeds half of the load Fz, the tread portion of the tire 10 is lifted by the lateral force Fy (α), so the relationship between the lateral deformation of the side portion and the virtual lateral displacement amount Δy (α) Collapse. For this reason, the accuracy of the virtual lateral displacement amount Δy (α) obtained from the lateral deformation of the right triangle shown in FIG.

  FIG. 9 is a diagram comparing the lateral spring constant obtained by the method of the present embodiment with the lateral spring constant obtained by a conventional method for measuring a static lateral spring constant. FIG. 9 shows the results of the lateral spring constant of tires A and B (tire size: 195 / 65R15, air pressure 230 kPa, load load Fz = 4.2 kN). In FIG. 9, a to d indicate the positions of the four tread portions on the tire circumference, and are the results of static lateral spring constants when the non-rotating tire is grounded to the road surface at each position. It can be seen that the tires A and B have different lateral spring constants at tread positions on the tire circumference. In particular, the variation in the lateral spring constant of the tire A is large, and it is determined that the lateral spring constant is larger than that of the tire B at the position a of the tire A, and that the lateral spring constant is smaller than that of the tire B at the position b of the tire A. Is done. Thus, since the static lateral spring constant according to the conventional method varies, the lateral spring constant of the tire cannot be evaluated correctly. On the other hand, in the present embodiment, since the average lateral spring constant on the tire circumference when the tire is rolled, the lateral spring constant of the tire is more accurate than the conventional static lateral spring constant. Can be evaluated.

10A and 10B are diagrams showing an example of the results of the lateral spring constant Ky calculated in the present embodiment and the lateral spring constant obtained by the conventional method. FIG. 10A shows the lateral spring constant _KLr calculated by using the tire dynamic model from the lateral force measurement data at the time of transient response when the tire is given a slip angle, and the lateral spring constant calculated in the present embodiment. The correspondence with Ky is shown. FIG. 10B shows a conventional method for calculating a static lateral spring constant (a non-rotating tire is brought into contact with the road surface at the position of one tread portion on the tire circumference to give a lateral displacement to obtain a lateral spring constant. The correspondence relationship between the conventional lateral spring constant obtained by (Calculation method) and the lateral spring constant _KLr is shown. The lateral spring constant _{K Lr} are those calculated by the method described in JP 2012-171467. As described in the above publication, the lateral spring constant _KLr is a value that can accurately reproduce the measurement data of the lateral force during the tire transient response using a tire dynamic model. Therefore, it can be said that the lateral spring constant K _Lr represents the actual lateral spring constant of the tire.
For such lateral spring constant K _Lr, as shown in FIG. 10 (a), the horizontal guess constant Ky of the present embodiment may correspond, to have a high correlation with the lateral spring constant K _Lr Recognize. In contrast, the conventional static lateral spring constant has a low correlation with the lateral spring constant _KLr , as shown in FIG. From this, the effect of the lateral spring constant Ky of this embodiment is clear.

  As described above, the tire characteristic calculation method and the tire characteristic calculation apparatus of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiment, and various improvements and modifications are made without departing from the gist of the present invention. Of course it is also good.

DESCRIPTION OF SYMBOLS 10 Tire 12 Road surface 14 Tire rotating shaft 16 Lateral deformation 20 Tire characteristic calculation apparatus 22 Data acquisition part 24 1st calculating part 26 2nd calculating part 30 Output device

Claims (9)

A tire characteristic calculation method for calculating tire characteristics using a computer,
Data on the separation distance with slip angle between the tire rotation axis and the road surface, and data on the lateral force of the tire in a condition where the tire is rolled by applying a slip angle to the road surface on the road surface, A step in which the computer obtains,
The computer uses the data of the separation distance with the slip angle and the data of the 0 degree separation distance between the rotating shaft and the road surface during rolling of the tire when the slip angle is 0 degree, Calculating a virtual lateral displacement amount in which the tire is virtually laterally displaced on the road surface;
And a step of calculating a lateral spring constant of the rolling tire by using the lateral force data and the virtual lateral displacement amount.   In the step of calculating the virtual lateral displacement amount, a square root of a difference obtained by subtracting a square of the data of the separation distance with slip angle from the square of the data of the 0 degree separation distance is set as the virtual lateral displacement amount. The tire characteristic calculation method described.   In the step of calculating the virtual lateral displacement, the 0 value is obtained from the first value obtained by multiplying the 0 degree separation distance data by ε (ε is a constant greater than 0 and less than 1), and the slip angle separation distance data. A second value obtained by subtracting (1−ε) times the value of the distance data is obtained, and the square root of the difference obtained by subtracting the square of the second value from the square of the first value is The tire characteristic calculation method according to claim 1, wherein a virtual lateral displacement amount is used.   The computer acquires tire slip distance data and tire lateral force data under a plurality of conditions in which the slip angle is changed by a plurality of values, and the slip angle in each condition. By obtaining a relationship between the virtual lateral displacement amount and the lateral force data, and calculating a gradient with respect to the virtual lateral displacement amount of the lateral force data when the virtual lateral displacement amount becomes 0 from the relationship, The tire characteristic calculation method according to any one of claims 1 to 3, wherein a lateral spring constant of the rolling tire is calculated.   The tire characteristic calculation method according to claim 4, wherein the plurality of conditions of the slip angle include an angle greater than 0 degrees and an angle smaller than 0 degrees.   The slip distance-separated distance data used for calculating the virtual lateral displacement amount is obtained when the lateral force data is equal to or less than half of a vertical load when the tire is brought into contact with the road surface to roll the tire. The tire characteristic calculation method according to any one of claims 1 to 5, which is data. A tire characteristic calculation device for calculating tire characteristics,
Data on the separation distance with a slip angle between the rotation axis of the tire and the road surface, and data on the lateral force of the tire in a condition in which the tire is rolled by applying a slip angle to the road surface on the road surface, A data acquisition unit for acquiring
The tire on the road surface using the slip distance separation data and the 0 degree separation data between the rotating shaft and the road surface during rolling of the tire when the slip angle is 0 degrees. A first arithmetic unit that calculates a virtual lateral displacement amount that is virtually laterally displaced;
A tire characteristic calculation device comprising: a second calculation unit that calculates a lateral spring constant of a rolling tire using the lateral force data and the virtual lateral displacement amount.   8. The tire according to claim 7, wherein the first arithmetic unit uses a square root of a difference obtained by subtracting a square of the data of the separation distance with slip angle from a square of the data of the 0-degree separation distance as the virtual lateral displacement amount. Characteristic calculation device. The first computing unit calculates the 0 degree separation distance from the first value obtained by ε times the constant of the 0 degree separation data (ε is a constant greater than 0 and less than 1) and the separation data with the slip angle. A second value obtained by subtracting a value obtained by multiplying the data of (1−ε) by a value obtained by subtracting the square of the second value from the square of the first value, and calculating the square root of the difference. The tire characteristic calculation device according to claim 7, wherein the tire characteristic is an amount.

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