Tire testing data creation device, data creation method, and program

Abstract

To generate tire testing data that can control a tire testing device highly accurately.SOLUTION: A data creation device 1 comprising a control section 12, is configured to: acquire force data representing a distribution of an occurrence frequencies of gravitational accelerations acting on a tire, based on travel data of a vehicle having traveled on a road; obtain a first force data distribution that is a distribution of force data acting in a lateral direction of the tire, a second force data distribution that is a distribution of force data acting in a longitudinal direction of the tire; divide the first force data distribution in a height direction and approximates the divided first force data distribution, in a manner of stacking first rectangles with heights thereof being division lengths thereof, respectively, and divide the second force data distribution in a height direction and approximates in a manner of stacking second rectangles with heights thereof being division lengths thereof, respectively; and generate first tire testing data representing forces corresponding to Y-coordinates, respectively, and second tire testing data representing forces corresponding to X-coordinates, respectively, for a plurality of ellipses specified according to widths of the first rectangles and widths of the second rectangles with a center on an XY plane as an origin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a data creation device, a data creation method, and a program for tire testing. [Background technology]

[0002] Conventionally, techniques for performing indoor tire wear tests have been known. For example, Patent Document 1 discloses a method for performing indoor tire wear tests by creating force data when a vehicle is actually driven on a wear test course and using the created force data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2004-522953 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it has been difficult to control the input to a tire testing device with high precision.

[0005] In view of the above circumstances, an object of the present disclosure is to create tire test data that can control a tire testing device with high precision. [Means for solving the problem]

[0006] The gist of the present disclosure for solving the above problems is as follows.

[0007] (1) A data creation device for tire testing that includes a control unit, the control unit acquiring force data indicating a distribution of occurrence frequencies of gravitational acceleration acting on a tire based on driving data when a vehicle travels on a road, determining from the force data a first force data distribution that is a distribution of force data acting in the left-right direction of the tire and a second force data distribution that is a distribution of force data acting in the front-rear direction of the tire, dividing the first force data distribution in a height direction and approximating it with a stack of multiple first rectangles whose height is a division length, dividing the second force data distribution in the height direction and approximating it with a stack of multiple second rectangles whose height is a division length, and creating first tire test data indicating forces corresponding to Y coordinates and second tire test data indicating forces corresponding to X coordinates for multiple ellipses whose centers are the origin on an XY plane and defined by the widths of the first and second rectangles. This configuration makes it possible to create tire test data that allows the tire testing device to be controlled with high precision.

[0008] (2) The data creation device according to (1), wherein the control unit divides the first force data distribution and the second force data distribution at equal intervals in the height direction. This configuration allows the tire testing device to apply force evenly and uniformly to the tire.

[0009] (3) The data creation device according to (1) or (2), wherein the amount of change in the first tire test data and the second tire test data is 100 N / s or less. This configuration makes it possible to generate tire test data that allows the input to the tire testing device to be gradually changed.

[0010] (4) A data creation method in which a data creation device for tire testing executes the steps of: acquiring force data indicating a distribution of occurrence frequencies of gravitational acceleration acting on a tire based on driving data when a vehicle runs on a road; determining from the force data a first force data distribution which is a distribution of force data acting in the left-right direction of the tire and a second force data distribution which is a distribution of force data acting in the front-rear direction of the tire; dividing the first force data distribution in the height direction and approximating it with a stack of multiple first rectangles whose height is a division length, and dividing the second force data distribution in the height direction and approximating it with a stack of multiple second rectangles whose height is a division length; and creating first tire test data indicating forces corresponding to Y coordinates and second tire test data indicating forces corresponding to X coordinates for multiple ellipses whose centers are the origin on an XY plane and defined by the widths of the first and second rectangles. This procedure makes it possible to generate tire test data that allows for highly accurate control of the tire testing machine.

[0011] (5) A program for causing a computer to function as the data creation device according to any one of (1) to (3). This configuration makes it possible to create tire test data that allows the tire testing device to be controlled with high precision. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to control a tire testing device with high precision. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of the configuration of a data creation device for tire testing according to an embodiment; [Figure 2] FIG. 1 is a schematic diagram showing force data. [Figure 3] 3 is a flowchart illustrating an example of a procedure for a tire test data creation method according to an embodiment. [Figure 4] FIG. 10 is a diagram illustrating approximation of force data. [Figure 5] FIG. 2 is a schematic diagram showing the force applied to a tire by a tire testing device. [Figure 6] FIG. 1 is a schematic diagram illustrating tire test data according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, one embodiment will be described in detail with reference to the drawings.

[0015] FIG. 1 shows an example of the configuration of a data creation device for tire testing according to one embodiment. The tire test is, for example, a tire wear test. The data creation device 1 shown in FIG. 1 includes an input unit 11, a control unit 12, a storage unit 13, and an output unit 14. The data creation device 1 may further include a communication I / F such as a LAN (Local Area Network) I / F to enable communication with an external device.

[0016] The input unit 11 is, for example, a physical key, a capacitance key, a pointing device, or a touch screen integrated with a display. The input unit 11 accepts an operation to input data used for the operation of the data creation device 1. The input unit 11 may be connected to the data creation device 1 as an external input device instead of being provided in the data creation device 1. As a connection interface, any interface compatible with standards such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface, registered trademark), or Bluetooth (registered trademark) may be used.

[0017] The storage unit 13 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, a random access memory (RAM), a read only memory (ROM), or a flash memory. The RAM is, for example, a static random access memory (SRAM) or a dynamic random access memory (DRAM). The ROM is, for example, an electrically erasable programmable read only memory (EEPROM). The flash memory is, for example, a solid-state drive (SSD). The magnetic memory is, for example, a hard disk drive (HDD). The storage unit 13 functions, for example, as a main storage device, an auxiliary storage device, or a cache memory.

[0018] The control unit 12 may be configured with dedicated hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), or may be configured with a processor, or may be configured with both. The control unit 12 executes processes related to the operation of the data creation device 1 while controlling each part of the data creation device 1.

[0019] The output unit 14 is, for example, a display, a speaker, or a printer, and presents the data created by the control unit 12 to the user. The display is, for example, an LCD (liquid crystal display) or an organic EL (electro luminescent) display. The output unit 14 may be connected to the data creation device 1 as an external output device instead of being provided in the data creation device 1. As a connection interface, any interface compatible with standards such as USB, HDMI, or Bluetooth can be used.

[0020] The control unit 12 shown in FIG. 1 includes a force data creation unit 121 and a tire test data creation unit 122.

[0021] The force data creation unit 121 receives travel data when a vehicle (actual vehicle) travels on roads including flat roads and hilly roads via the input unit 11. The travel data includes information related to speed and steering angle.

[0022] The force data creation unit 121 creates force data (G distribution data) that indicates the distribution of occurrence frequencies (distance frequencies) of gravitational acceleration acting in the front-rear and left-right directions of the tire over the entire travel distance, based on the travel data input from the input unit 11. The force data creation unit 121 may remove noise from the force data using a noise filter. The force data creation unit 121 outputs the created force data to the tire test data creation unit 122. When the force data is input to the tire test data creation unit 122 via the input unit 11, the data creation device 1 does not need to include the force data creation unit 121.

[0023] Figure 2 shows a schematic diagram of the force data. Here, the Y axis represents the gravitational acceleration in the left-right direction of the tire (equivalent lateral G), the X axis represents the gravitational acceleration in the front-rear direction of the tire (equivalent front-rear G), and the Z axis represents the distance frequency. The force data is three-dimensional data, but Figure 2 shows the force data on the YZ plane and the force data on the XZ plane.

[0024] The tire test data creation unit 122 receives the force data from the force data creation unit 121. The tire test data creation unit 122 converts the force data into tire test data. The tire test data is data that is input to a tire testing device.

[0025] Next, a method for creating data for a tire test according to an embodiment will be described below with reference to a flowchart of FIG.

[0026] In step S101, the tire test data creation unit 122 obtains, from the force data, a distribution of force data acting in the left-right direction of the tire (hereinafter referred to as the "first force data distribution") and a distribution of force data acting in the front-rear direction of the tire (hereinafter referred to as the "second force data distribution") as shown in FIG. 2.

[0027] In step S102, the tire test data creation unit 122 divides the first force data distribution into n parts in the height direction (Z direction) as shown in Fig. 4, and approximates it by stacking a plurality of first rectangles A1 to An, whose height is the division length. Also, the tire test data creation unit 122 divides the second force data distribution into n parts in the height direction as shown in Fig. 4, and approximates it by stacking a plurality of second rectangles B1 to Bn, whose height is the division length. In the example shown in Fig. 4, the number of divisions n=5, but n can be any value equal to or greater than 2.

[0028] The tire test data creation unit 122 may divide the first force data distribution and the second force data distribution at equal intervals in the height direction, so that the heights of the first rectangles A1 to An and the second rectangles B1 to Bn are equal. By making the division lengths constant, it is possible to apply force to the tire evenly and without bias in the tire testing device.

[0029] As shown in Fig. 5, at time t1, the tire testing device applies a force represented by an ellipse C1 with zero inclination, defined by the width of the first rectangle A1 and the width of the second rectangle B1, with its center at the origin in the XY plane (the ellipse C1 has one of the widths of the first rectangle A1 and the second rectangle B1 as its minor axis and the other as its major axis). Similarly, at time t2, the tire testing device applies a force represented by an ellipse C2 with zero inclination, defined by the width of the first rectangle A2 and the width of the second rectangle B2, with its center at the origin in the XY plane. By repeating this operation until time tn, a force corresponding to the force data shown in Fig. 2 can be evenly applied to the tire.

[0030] In step S103, the tire test data creation unit 122 creates tire test data for causing the tire testing apparatus to perform the operations described with reference to Fig. 5. Specifically, as shown in the upper part of Fig. 6, the tire test data creation unit 122 creates first tire test data indicating forces corresponding to the Y coordinates of ellipses C1 to Cn in order as data indicating the load on the tire in the left-right direction. Also, as shown in the lower part of Fig. 6, the tire test data creation unit 122 creates second tire test data indicating forces corresponding to the X coordinates of ellipses C1 to Cn in order as data indicating the load on the tire in the front-rear direction. Note that in a typical tire testing apparatus, forces in the left-right direction are easier to control and have higher sensitivity than forces in the front-rear direction of a tire. Therefore, in the example shown in Fig. 6, the forces in the left-right direction are changed finely and the forces in the front-rear direction are changed slowly at each of times t1 to tn.

[0031] For example, if the step size (control unit) of the force data is 0.03 G, and the tire load is 5000 N, the step sizes of Fx and Fy will be 150 N. If the control time for each step size is 3 seconds, the sweep speed will be 50 N / s, and the change amount of the first tire test data and the second tire test data will also be 50 N / s. Shortening the control time for the step size improves the reproducibility of the force distribution, but from the perspective of test accuracy and the specifications (constraints) of the tire test device, it is necessary to gradually change the input to the tire test device. Furthermore, considering factors such as general tire loads, it is preferable to set the change amount of the first tire test data and the second tire test data to 100 N / s or less.

[0032] The data creation device 1 inputs the first tire test data and the second tire test data thus created into a tire testing device in a combined manner. In the tire testing device, by combining the first tire test data (input in the left-right direction) and the second tire test data (input in the front-rear direction), it becomes possible to control the input to the tire testing device with high precision. For example, it becomes possible to avoid sudden changes in the input and change the input gradually.

[0033] <Program> A computer capable of executing program instructions can also be used to function as the above-described data creation device 1. Here, the computer may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), an electronic notepad, a mobile terminal, etc. The program instructions may be program code, code segments, etc. for performing the necessary tasks.

[0034] The control unit 12 is a processor such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), or SoC (System on a Chip), and may be configured with multiple processors of the same or different types. The processor performs the above-mentioned processing by reading and executing a program from the storage unit 13. Note that at least a part of the processing content may be realized by hardware.

[0035] The program may be recorded on a computer-readable recording medium. Using such a recording medium, the program can be installed on a computer. Here, the recording medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a CD-ROM, a DVD-ROM, or a USB (Universal Serial Bus) memory. Furthermore, the program may be downloaded from an external device via a network.

[0036] The above-described embodiments have been described as representative examples, but it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications or alterations are possible without departing from the scope of the claims. For example, it is possible to integrate multiple building blocks shown in the configuration diagrams of the embodiments, or to divide a single building block. It is also possible to integrate multiple steps shown in the flowcharts of the embodiments into one, or to divide a single step. Contribution to the Sustainable Development Goals (SDGs) led by the United Nations

[0037] The SDGs have been proposed to realize a sustainable society. One embodiment of the present invention is expected to contribute to the achievement of "No. 9 - Building infrastructure for industry and technological innovation." [Explanation of symbols]

[0038] 1. Data creation device 11 Input section 12 Control Unit 13 Storage section 14 Output section 121 Force Data Creation Department 122 Tire Test Data Creation Department

Claims

1. A data creation device for tire testing that includes a control unit, The control unit Obtain force data that indicates the distribution of the frequency of occurrence of gravitational acceleration acting on the tires based on driving data when the vehicle is traveling on a road, a first force data distribution, which is a distribution of force data acting in a left-right direction of the tire, and a second force data distribution, which is a distribution of force data acting in a front-rear direction of the tire, are obtained from the force data; Dividing the first force data distribution in a height direction and approximating it with a stack of a plurality of first rectangles whose height is a division length, and dividing the second force data distribution in a height direction and approximating it with a stack of a plurality of second rectangles whose height is a division length, a data creation device that creates first tire test data indicating forces corresponding to Y coordinates and second tire test data indicating forces corresponding to X coordinates for a plurality of ellipses in an XY plane, the ellipses having their centers as origins and defined by the widths of the first rectangle and the second rectangle;

2. The data creation device according to claim 1 , wherein the control unit divides the first force data distribution and the second force data distribution at equal intervals in a height direction.

3. Data creation device for tire testing acquiring force data indicating a distribution of occurrence frequencies of gravitational acceleration acting on the tires based on running data when the vehicle runs on a road; obtaining, from the force data, a first force data distribution which is a distribution of force data acting in a left-right direction of the tire, and a second force data distribution which is a distribution of force data acting in a front-rear direction of the tire; Dividing the first force data distribution in a height direction and approximating it with a stack of a plurality of first rectangles whose height is a division length, and dividing the second force data distribution in a height direction and approximating it with a stack of a plurality of second rectangles whose height is a division length; generating first tire test data indicating a force corresponding to a Y coordinate and second tire test data indicating a force corresponding to an X coordinate for a plurality of ellipses in an XY plane, the ellipses having a center as an origin and defined by the width of the first rectangle and the width of the second rectangle; A data creation method that performs the following.

4. A program for causing a computer to function as the data creation device according to claim 1 or 2.

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