System for measuring force acting on tread of tire, method for measuring force acting on tread of tire, and program for measuring force acting on tread of tire

Abstract

To provide a system and the like for measuring a force acting on the tread of a tire capable of high-definition measurement of the force without increasing the number of force detection units for measuring the force.SOLUTION: Provided is a measurement system 1 for measuring a force acting on the tread of a tread part 2 of a tire T. The measurement system 1 includes a force detection unit 4, a tire rotation position detection unit 10, a data processing unit 13 that processes data from the force detection unit 4 and the tire rotation position detection unit 10. A detection surface of the force detection unit 4 has a first length in a drum circumferential direction, and the tire rotation position detection unit 10 can detect the rotation position of the tire in a tire circumferential direction in units of a second length smaller than the first length. The data processing unit 13 includes a force storage unit and an averaging unit. The force storage unit stores force data within the first length in a data storage area in units of the second length. When the force data is stored multiple times at the same tire rotation position, the averaging unit averages the force data.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for measuring forces acting on the contact patch of a tire. [Background technology]

[0002] Measuring the forces acting on the contact patch of a tire running on a road surface is important in evaluating the tire's ground contact characteristics. An example of such a measurement method is described in, for example, Patent Document 1 below. The measurement method in Patent Document 1 uses a test device equipped with a rotation angle detector that detects the rotation angle of the tire, a tire stress measuring device installed on the road surface of the drum, and a rotation angle detector that detects the rotation angle of the drum. The tire stress measuring device uses a three-component force sensor, and its detection unit is arranged so as to be in contact with the surface of the tire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-090234 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to measure the force acting on the tire contact patch with high precision, it is effective to, for example, miniaturize the force detection units that come into contact with the tire tread and increase their placement density. However, this approach has the problem of increasing the cost of the system for measuring the force acting on the tire contact patch.

[0005] The present invention has been devised in view of the above-mentioned problems, and its main object is to provide a system for measuring the force acting on the tire contact surface that can measure the force acting on the tire contact surface with high precision without increasing the number of force detection units that measure the force acting on the tire contact surface. [Means for solving the problem]

[0006] The present invention is a measurement system for measuring forces acting on the contact surface of a tire tread portion, the system including: a force detection unit provided on the running surface of a cylindrical drum and for measuring forces acting on the contact surface of the tire running on the running surface; a tire rotational position detection unit for detecting the rotational position of the tire running on the running surface; and a data processing unit for receiving and processing data from the force detection unit and the tire rotational position detection unit, respectively; the force detection unit has a detection surface that outputs force data by coming into contact with the tire, the detection surface having a first length in the drum circumferential direction, and the tire rotational position detection unit is capable of detecting the rotational position of the tire in the tire circumferential direction in units of a second length that is smaller than the first length; and the data processing unit includes: a force memory unit that stores force data within the first length range from the force detection unit in a data memory area in units of the second length; and an averaging unit that averages the force data stored multiple times when the force data is stored multiple times at the same tire rotational position stored in the data memory area. [Effects of the Invention]

[0007] By adopting the above-described configuration, the system for measuring the forces acting on the tire contact surface of the present invention can measure the forces acting on the tire contact surface with high precision without increasing the number of force detection units that measure the forces acting on the tire contact surface. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall view of a system for measuring forces acting on the contact patch of a tire according to an embodiment of the present invention. [Figure 2] FIG. 1 is a conceptual diagram showing the configuration of a measurement system according to an embodiment of the present invention. [Figure 3] FIG. 2 is an enlarged perspective view showing the force detection unit of FIG. [Figure 4] 3 is a flowchart showing the processing procedure of the measurement method of the present embodiment. [Figure 5] 2 is an enlarged side view of the drum and tire of FIG. 1 as viewed from the x-axis direction. FIG. [Figure 6] 10 is a graph conceptually showing data obtained in the force detection step S1 of the present embodiment. [Figure 7] 10 is a flowchart showing a processing procedure of a data processing step. [Figure 8] FIG. 10 is an explanatory diagram conceptually showing stored force data. [Figure 9] FIG. 10 is an explanatory diagram conceptually showing stored force data. [Figure 10] FIG. 10 is an explanatory diagram showing a process of averaging force data. [Figure 11] 10 is a flowchart showing a processing procedure of a data averaging step. [Figure 12] FIG. 10 is a schematic diagram showing a distribution image of forces acting on the contact patch of a tire displayed on a display device. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will now be described with reference to the drawings. 1 is an overall view of a measurement system 1 (hereinafter simply referred to as "measurement system") for measuring the force acting on the contact patch of a tire according to this embodiment. Note that although the drawings are intended to encompass the features of the present invention, they may contain exaggerated expressions or expressions that differ from the dimensional ratios of the actual structure in order to enhance understanding of the contents of the invention.

[0010] As shown in Fig. 1, the measurement system 1 of this embodiment is for measuring the force acting on the contact surface of a tread portion 2 of a tire T. Fig. 1 shows a passenger vehicle tire as an example of the tire T to be measured, but the tire is not limited to this, and the measurement system 1 can measure various tires such as heavy-duty tires, motorcycle tires, and airless tires.

[0011] FIG. 2 is a conceptual diagram showing the configuration of a measurement system 1 according to this embodiment. As shown in FIGS. 1 and 2, the measurement system 1 according to this embodiment measures the forces acting on the contact patch of the tread portion 2 by running a tire T on a drum 3, thereby determining the distribution of forces acting on each part of the contact patch. The measurement system 1 according to this embodiment includes, as devices 20, the drum 3, a drum support device 6, a tire support device 9, a force detection unit 4, and a tire rotational position detection unit 10. The measurement system 1 also includes a data processing unit 13 as a control unit 7 that controls these devices 20. The control unit 7 of the measurement system 1 includes a known arithmetic unit 30 including a CPU 31, a working memory 32, a storage device 33, etc., and the operations of each unit, which will be described later, are realized by a program unit 29 of the arithmetic unit 30.

[0012] [drum] The drum 3 is used for running the tire T. The drum 3 is formed in a cylindrical shape having a running surface 3a (shown in FIG. 1). The drum 3 of this embodiment has the running surface 3a on its inner circumferential surface for running the tire T. In another embodiment, the drum 3 may have the running surface 3a on its outer circumferential surface for running the tire T.

[0013] The drum 3 in this embodiment is, for example, larger than the outer diameter of the tire T. The inner diameter of the drum 3 in this embodiment is, for example, 4000 to 6000 mm, and is set to 5000 mm in this embodiment. In a desirable aspect, the inner diameter of the drum 3 is set to be different from an integer multiple of the outer diameter of the tire T. This makes it possible to prevent the same position of the contact surface of the tire T from contacting a specific location on the running surface 3a of the drum 3 multiple times when the tire T runs by rotating the drum 3 multiple times.

[0014] [Drum support device] 1, the drum support device 6 supports the drum 3 and can rotate it. In this embodiment, the drum support device 6 extends so that the rotation axis of the drum 3 is parallel to the x-axis, and drives the drum 3 to rotate around the x-axis. The drum support device 6 starts and stops operation in response to commands from the control unit 7, for example.

[0015] [Tire support device] The tire support device 9 of this embodiment can support and rotate a tire T. The tire support device 9 also supports the tire T rotatably and movably in the drum axial direction. The tire support device 9 starts and ends operation in response to a command from the control unit 7, for example.

[0016] [Force detection unit] The force detection unit 4 is for measuring the force acting on the contact surface of the tire T running on the running surface 3a. The force detection unit 4 is provided on the running surface 3a of the cylindrical drum 3. FIG. 3 is an enlarged perspective view showing the force detection unit 4 of FIG. 1. As shown in FIG. 3, the force detection unit 4 of this embodiment is disposed on the running surface 3a of the drum 3, for example, and measures the force acting on the contact surface of the tire T when the tire T passes over the force detection unit 4.

[0017] The force detection unit 4 includes a sensor 4b capable of detecting a force acting on a detection surface 4a. The force detection unit 4 outputs force data when the detection surface 4a comes into contact with the tire T. In a preferred embodiment, the sensor 4b is embedded in the plate 5 and fixed so that the detection surface 4a of the sensor 4b is substantially flush with the running surface 3a of the drum 3. Here, "substantially" means that the embodiment does not affect the force measurement when the measurement system 1 is implemented.

[0018] The detection surface 4a of the sensor 4b is formed in, for example, a circular shape, but may also be in, for example, a rectangular shape.

[0019] The detection surface 4a has a first length L1 in the drum circumferential direction. In this embodiment, the first length L1 is, for example, 5 to 7 mm. However, the length L1 is not limited to this.

[0020] In this embodiment, a plurality of sensors 4b constituting the force detection unit 4 are arranged in the x-axis direction. In this embodiment, the sensors 4b are arranged, for example, in a row at equal intervals in the x-axis direction. In another embodiment, a plurality of rows of sensors 4b arranged in the x-axis direction may be arranged in the rotation direction of the drum 3.

[0021] The sensor 4b of this embodiment is configured as a three-component force sensor that can detect forces acting on the detection surface 4a in three directions. Such a sensor 4b can measure forces in the x-axis, y-axis, and z-axis directions shown in Fig. 3, and can analyze the forces acting on the contact patch of the tire T in more detail. The sensor 4b of this embodiment can simultaneously measure forces in these three directions and output the respective data separately.

[0022] [Tire rotation position detection unit] 1 and 2, the measurement system 1 includes a tire rotational position detection unit 10 for detecting the rotational position of a tire T traveling on a traveling surface 3a. The tire rotational position detection unit 10 of this embodiment is attached to a tire support device 9. Any known tire rotational position detection unit can be appropriately adopted as this tire rotational position detection unit 10 as long as it can detect the rotational angle of the tire T. A rotary encoder is adopted as the tire rotational position detection unit 10 of this embodiment.

[0023] The tire rotational position detection unit 10 detects the rotational position of the tire T in the tire circumferential direction in units of a second length L2 that is smaller than the first length L1. From the viewpoint of realizing this, the tire rotational position detection unit 10 of this embodiment has a resolution that can detect the amount of rotation of the tire T in units of 0.1 degrees, for example. From the same viewpoint, the tire rotational position detection unit 10 of this embodiment preferably has a resolution that can detect the amount of rotation of the tire T at the contact patch in units of 1.0 mm, for example, and more preferably has a resolution that can detect the amount of rotation of the tire T at the contact patch in units of 0.5 mm.

[0024] [Data Processing Unit] The data processing unit 13 receives and processes data from the force detection unit 4 and the tire rotational position detection unit 10. The data processing unit 13 of this embodiment includes a force storage unit 16 and an averaging unit 17.

[0025] [Force memory section] The force storage unit 16 stores the force data within the range of the first length L1 from the force detection unit 4 in the data storage area 12 in units of the second length L2.

[0026] [Averaging section] When force data is stored multiple times at the same tire rotation position stored in the data storage area 12, the averaging unit 17 averages the force data stored multiple times.

[0027] In conventional measurement systems, the measurement accuracy depends on the size of the detection surface of the force detection unit. In other words, in order to improve the measurement accuracy of a conventional measurement system, it was necessary to reduce the size of the detection surface of the sensors arranged in the force detection unit and increase the arrangement density of the sensors.

[0028] In contrast, the measurement system 1 of the present invention includes the tire rotational position detection unit 10, which stores force data within the first length range in units of the second length, and the averaging unit 17 averages the force data stored multiple times at the same tire rotational position. This makes it possible to measure the force acting on the contact patch of the tread portion 2 with high precision, essentially in units of the second length L2. Therefore, the measurement system 1 of the present invention can measure the force acting on the contact patch of the tire T with high precision, without increasing the number of force detection units 4 or making them smaller.

[0029] As shown in FIGS. 1 and 2, in a more preferable embodiment, the measurement system 1 of this embodiment further includes a drum rotation position detection unit 8.

[0030] [Drum rotation position detection unit] The drum rotational position detection unit 8 of this embodiment is attached to the drum support device 6 and can detect the rotation angle of the drum 3. The measurement system 1 of this embodiment includes not only the tire rotational position detection unit 10 but also the drum rotational position detection unit 8, thereby making it possible to detect the relative positional relationship between the force detection unit 4 and the contact surface of the tire T with higher accuracy. Specific operations of these components will be described later.

[0031] Next, a measurement method performed in the measurement system 1 of the present invention will be described. Fig. 4 is a flowchart showing an example of the processing procedure of the measurement method of this embodiment. As shown in Fig. 4, the measurement method of this embodiment includes a force detection step S1, a tire rotational position detection step S2, and a data processing step S3.

[0032] [Force detection step S1] In the force detection step S1, first, the force acting on the contact patch of the tire T is detected. FIG. 5 is an enlarged side view of the drum 3 and tire T in FIG. 1 as viewed from the x-axis direction. As shown in FIG. 5, in this embodiment, the force acting on the contact patch of the tire T is detected from a start point PS, at which the force detection unit 4 starts contacting the tire T, to an end point PE, at which the force detection unit 4 separates from the tire T. The midpoint between the start point PS and the end point PE is set as a reference point PR. The reference point PR is located directly below the rotation axis of the tire T.

[0033] In the force detection step S1, force data is output within a range of a first length L1 (shown in FIG. 3) in the drum circumferential direction. That is, while the sensor 4b (shown in FIG. 3) of the force detection unit 4 passes from the start point PS to the end point PE, force data acting within the range of the length of the detection surface 4a of the force detection unit 4 in the drum circumferential direction is obtained.

[0034] FIG. 6 shows a graph conceptually illustrating the data obtained in the force detection step S1 of this embodiment. In this embodiment, the sensor 4b of the force detection unit 4 is a three-component force sensor. Therefore, in the force detection step S1 of this embodiment, data on forces acting in the x-axis direction, y-axis direction, and z-axis direction is obtained. While FIG. 6 shows this force data as a graph from the start point PS to the end point PE, the actual force data is a collection of specific numerical values ​​of forces acting in the x-axis direction, y-axis direction, and z-axis direction at each position from the start point PS to the end point PE. Note that, if this force data is used as is, it is force data acquired within the range of the first length L1, and therefore, similar to conventional technology, high accuracy cannot be expected.

[0035] [Tire rotation position detection step S2] 1 and 2, in the tire rotational position detection step S2, the rotational position of the tire T traveling on the traveling surface 3a is detected. In addition, in the tire rotational position detection step S2 of this embodiment, the rotational position of the tire T is detected in the tire circumferential direction in units of a second length L2 that is smaller than a first length L1 (shown in FIG. 3). In this embodiment, by operating not only the tire rotational position detection unit 10 but also the drum rotational position detection unit 8, the rotational position of the tire T is detected with higher accuracy.

[0036] In this embodiment, the tire T is caused to run on the drum 3, and the force detection step S1 and the tire rotational position detection step S2 are continuously performed so that data about the entire contact patch of the tire T can be obtained. More specifically, the tire support device 9 causes the tire T to run on the drum 3 while slightly moving the tire T in its axial direction, and the force detection step S1 and the tire rotational position detection step S2 are continuously performed. This makes it possible to obtain data about the entire contact patch of the tire T.

[0037] [Data processing step S3] In the data processing step S3, data is received and processed from the force detection unit 4 and the tire rotational position detection unit 10. Fig. 7 is a flowchart showing the processing procedure of the data processing step S3. As shown in Fig. 7, the data processing step S3 includes a data storage step S31 and a data averaging step S32.

[0038] [Data storage step S31] In this data storage step S31, the tire rotational position data and the force data are stored in association with each other. Prior to this, a second length L2 is determined based on the resolution of the tire rotational position detection unit 10. The second length L2 is calculated, for example, by dividing the amount of rotation L5 (shown in FIG. 5) of the drum 3 from the start point PS to the end point PE by the number of pulses that the tire rotational position detection unit 10 can issue during this period.

[0039] 8 and 9 are explanatory diagrams conceptually showing the stored data. In FIGS. 8 and 9, the x-axis and y-axis directions correspond to the position information of the location where the force data was acquired. Furthermore, the rectangular parallelepiped block 23 shown in FIGS. 8 and 9 conceptually represents the force data measured at a specific point on the contact surface. One block 23 stores data on the forces acting in the x-axis, y-axis, and z-axis directions measured at the one point.

[0040] As shown in Figure 8, in this data storage step S31, tire rotational position data and force data are associated with each other, and the coordinates of the position where the force was measured and the specific magnitude of the force (as described above, the force is the force acting in the x-axis direction, y-axis direction, and z-axis direction) are stored. At this time, the data corresponding to each block 23 is force data divided into units of the second length L2. Note that Figure 8 conceptually shows a state in which one piece of force data (block 23) is stored for each position on the contact patch.

[0041] In the data storage step S31, as shown in the upper part of FIG. 9, multiple pieces of force data (blocks 23) are stored for each position on the contact patch. That is, in the measurement method of this embodiment, the tire T is caused to run on the drum 3, and multiple pieces of force data are obtained for each position on the contact patch and stored. In the upper part of FIG. 9, the second piece of force data (block 23) measured at each position is marked with a light dot, and the third piece of data (block 23) is marked with a dark dot. Although FIG. 9 illustrates an example in which up to three pieces of data (blocks 23) are stored per position, this is not intended to be limiting. That is, by increasing the distance that the tire T runs on the drum 3, even more data may be stored per position.

[0042] [Data averaging step S32] In the data averaging step S32, the multiple pieces of force data acquired at each position on the contact patch are averaged. That is, as conceptually shown in the upper and lower parts of Figure 9, when multiple pieces of force data (blocks 23) are acquired at each position, these pieces of data are averaged and stored. Note that in the lower part of Figure 9, light dots are used to indicate averages of two pieces of data (blocks 23), and dark dots are used to indicate averages of three pieces of data (blocks 23).

[0043] FIG. 10 is an explanatory diagram showing the above-mentioned process of averaging the force data. In FIG. 10, a set of force data from the start point PS to the end point PE is shown as waveform data D1 to D3, and the average of these is shown as waveform data Dav. As shown in FIG. 10, in the data averaging step S32, the force data is averaged to obtain highly precise data. In this embodiment, these processes can be performed over the entire contact patch of the tire T.

[0044] 11 is a flowchart showing the processing procedure of the above-mentioned data averaging step S32. As shown in FIG. 11, in the data averaging step S32 of this embodiment, first, the number n of the data storage area 12 is reset to 0 (step S321).

[0045] Next, in the data averaging step S32 of this embodiment, it is determined whether or not a plurality of pieces of force data D(n) are stored in the tire rotational position data P(n) identified by the number n in the data storage area 12 (step S322).

[0046] Next, in this embodiment, if it is determined that a plurality of pieces of force data D(n) are stored ("Yes" in step S322), the plurality of pieces of force data D(n) stored are integrated (step S323).

[0047] Next, in this embodiment, the integrated force data D(n) is averaged (step S324), and thereafter, it is determined whether the number n of the data storage area 12 is equal to the size N of the data storage area 12 (step S325).

[0048] In this embodiment, when it is determined that the number n of the data memory area 12 is equal to the size N of the data memory area 12 ("Yes" in step S325), that is, when it is determined that it has been checked whether multiple pieces of force data D(n) are stored for all tire rotation positions in the data memory area 12, all steps of the measurement method are completed.

[0049] On the other hand, if it is determined that the number n of the data memory area 12 is not equal to the size N of the data memory area 12 ("No" in step S325), that is, if it is determined that it has not been checked whether multiple pieces of force data D(n) are stored for all tire rotation positions in the data memory area 12, the number n of the data memory area 12 is incremented (step S326), and the determination in step S322 is performed again. In this way, the force data D(n) can be averaged until it has been checked whether multiple pieces of force data D(n) are stored for all tire rotation positions in the data memory area 12.

[0050] As described above, in the measurement system 1 and measurement method of this embodiment, even if the force detection unit 4 has a first length L1, the tire rotational position detection unit 10 detects force data in units of a second length L2 that is shorter than the first length L1. Furthermore, because the force data acquired at one position is averaged, the force acting on the contact patch of the tread portion 2 can be obtained with high precision substantially in units of the second length L2. Therefore, in the measurement system 1 and measurement method of the present invention, the force acting on the contact patch of the tire T can be measured with high precision without increasing the number of force detection units 4 that measure the force acting on the contact patch of the tire T.

[0051] More preferred aspects of the present embodiment will be described below, but the present invention is not limited to the following aspects.

[0052] 1 and 2, the data storage area 12 of this embodiment preferably corresponds to the tread surface region R with which the force detection unit 4 comes into contact. Here, "corresponding" means that the data storage area 12 is configured as a two-dimensional array, with one dimension of the two-dimensional array set in the tire axial direction and the other dimension of the two-dimensional array set in the tire circumferential direction, so that the data storage area 12 simulates the tread surface region R with which the force detection unit 4 comes into contact. This allows the force data averaging process in data processing step S3 to be efficiently performed by the program for measuring the force acting on the contact patch of the tire T.

[0053] The tread surface region R is an area of ​​one circumference of the tread portion 2 at least in the tire circumferential direction, more desirably in the tire circumferential direction and the tire axial direction. That is, in a desirable embodiment, the data storage region 12 corresponds to the entire area of ​​the tread surface region R. In this embodiment, the drum 3 is rotated multiple times, so that the force detection unit 4 comes into contact with the tire T multiple times. This makes it possible to obtain force data for the entire area of ​​the tread surface region R, and to measure the force acting on the contact patch of the tire T with high precision.

[0054] The drum rotational position detection unit 8 of this embodiment has a resolution for detecting the rotational position of the drum 3 with an accuracy of, for example, about 1 mm. Therefore, it is preferable that the drum rotational position detection unit 8 detects the rotational position of the drum 3 in units of a third length L3, which is smaller than the first length L1, in the drum circumferential direction. It is preferable that the third length L3 is equal to or smaller than half the first length L1. This makes it possible to accurately obtain data on the position of the tire T even if slippage occurs between the tire T and the drum 3. Therefore, it is possible to measure the force acting on the contact patch of the tire T with higher precision.

[0055] 3, the detection surface 4a of this embodiment has a fourth length L4 in the drum axial direction. The second length L2 described above is preferably equal to or less than half of this fourth length L4. This allows for more precise measurement of the force acting on the contact patch in the tire circumferential direction, thereby enabling more precise measurement of the force acting on the contact patch of the tire T in the tire circumferential direction and tire axial direction without increasing the number of force detection units 4.

[0056] FIG. 12 is a schematic diagram showing a distribution image Ig of forces acting on the contact patch of the tire T displayed on the display device 14. As shown in FIG. 12, the data processing unit 13 preferably further includes an image generation unit 15 that generates, based on the force data, a distribution image Ig of forces acting on the contact patch to be displayed on the display device 14 (shown in FIG. 1). In FIG. 12, the tread surface region R of the tire T is shown on the left side, and the distribution image Ig of forces acting on the contact patch of the tire T is shown on the right side. At a certain point in the tire circumferential direction (the point indicated by PR in FIG. 12) in the tread surface region R on the left side, the force data of the tire T in the x direction averaged between the start point PS and the end point PE is shown as the distribution image Ig on the right side. In this embodiment, the size of one pixel in the distribution image Ig is smaller than the first length L1. Therefore, the forces acting on the contact patch of the tire T can be measured with high resolution without increasing the number of force detection units 4 that measure the forces acting on the contact patch of the tire T, and consequently, the distribution image Ig can be generated with high resolution. In this embodiment, as described above, the force data is measured over the entire area of ​​the tread surface region R, so that the distribution image Ig can be obtained over the entire outer circumferential length L6 of the tire T.

[0057] Although a particularly preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the illustrated embodiment and can be modified and implemented in various ways.

[0058] [Note] The present invention includes the following aspects.

[0059] [Invention 1] A measurement system for measuring forces acting on a contact patch of a tire tread, comprising: a force detection unit provided on a running surface of a cylindrical drum and configured to measure a force acting on the contact surface of the tire running on the running surface; a tire rotational position detection unit for detecting a rotational position of the tire traveling on the traveling surface; a data processing unit for receiving and processing data from the force detection unit and the tire rotational position detection unit, the force detection unit has a detection surface that outputs force data by coming into contact with the tire, the detection surface has a first length in the drum circumferential direction, the tire rotational position detection unit is capable of detecting the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing unit a force storage unit that stores force data in the first length range from the force detection unit in a data storage area in units of the second length; an averaging unit that averages the force data stored multiple times when the force data is stored multiple times at the same tire rotation position stored in the data storage area, A system for measuring the forces acting on the tire contact patch. [Invention 2] The system for measuring the force acting on the contact patch of a tire according to aspect 1, wherein the data storage area corresponds to the tread surface area with which the force detection unit comes into contact. [Invention 3] 3. The system for measuring forces acting on the contact patch of a tire according to claim 2, wherein the tread surface area is an area of ​​one circumference of the tread portion in the tire circumferential direction. [Invention 4] The system for measuring forces acting on the contact patch of a tire according to aspect 2, wherein the tread surface area is an area of ​​one circumference of the tread portion in the tire circumferential direction and the tire axial direction. [Invention 5] Further comprising a drum rotation position detection unit for detecting the rotation position of the drum, the drum rotation position detection unit detects the rotation position of the drum in a drum circumferential direction in a third length unit, 5. The system for measuring the force acting on the contact patch of a tire according to any one of claims 1 to 4, wherein the third length is equal to or less than half of the first length. [Invention 6] the detection surface has a fourth length in the drum width direction, 6. The system for measuring the force acting on the contact patch of a tire according to any one of claims 1 to 5, wherein the second length is equal to or less than half of the fourth length. [Invention 7] The system for measuring forces acting on the tire contact patch according to any one of claims 1 to 6, wherein the data processing unit further includes an image generation unit that generates, based on the force data, an image of the distribution of forces acting on the contact patch to be displayed on a display device. [Invention 8] A measurement method for measuring the force acting on the contact surface of a tire tread, comprising: a force detection step of measuring a force acting on the contact surface of the tire running on a running surface of a cylindrical drum; a tire rotational position detection step for detecting a rotational position of the tire traveling on the traveling surface; a data processing step for receiving and processing the data obtained in the force detection step and the tire rotational position detection step, the force detecting step outputs force data within a range of a first length in the drum circumferential direction; the tire rotational position detecting step detects the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing step includes: storing the force data for the first length range obtained in the force detecting step in a data storage area in units of the second length; When the force data is stored a plurality of times at the same tire rotation position stored in the data storage area, the force data stored a plurality of times is averaged. A method for measuring the force acting on the tire's contact surface. [Invention 9] A measurement program for measuring a force acting on a contact surface of a tire tread, a force detection step of measuring a force acting on the contact surface of the tire running on a running surface of a cylindrical drum; a tire rotational position detection step for detecting a rotational position of the tire traveling on the traveling surface; a data processing step for receiving and processing the data obtained in the force detection step and the tire rotational position detection step, the force detecting step outputs force data within a range of a first length in the drum circumferential direction; the tire rotational position detecting step detects the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing step includes: storing the force data for the first length range obtained in the force detecting step in a data storage area in units of the second length; When the force data is stored a plurality of times at the same tire rotation position stored in the data storage area, the force data stored a plurality of times is averaged. A program for measuring the forces acting on the tire's contact surface. [Explanation of symbols]

[0060] 1. Measurement System 2 Tread section 3 Drums 3a Running surface 4 Force detection unit 10 Tire rotation position detection unit 13 Data Processing Unit T Tire

Claims

1. A measurement system for measuring forces acting on a contact patch of a tire tread, comprising: a force detection unit provided on a running surface of a cylindrical drum and configured to measure a force acting on the contact surface of the tire running on the running surface; a tire rotational position detection unit for detecting a rotational position of the tire traveling on the traveling surface; a data processing unit for receiving and processing data from the force detection unit and the tire rotational position detection unit, the force detection unit has a detection surface that outputs force data by coming into contact with the tire, the detection surface has a first length in the drum circumferential direction, the tire rotational position detection unit is capable of detecting the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing unit a force storage unit that stores force data in the first length range from the force detection unit in a data storage area in units of the second length; an averaging unit that averages the force data stored multiple times when the force data is stored multiple times at the same tire rotation position stored in the data storage area, A system for measuring the forces acting on the tire contact patch.

2. 2. The system for measuring a force acting on a tire contact patch according to claim 1, wherein the data storage area corresponds to a tread surface area that is in contact with the force detection portion.

3. 3. The system for measuring forces acting on a tire contact patch according to claim 2, wherein the tread surface area is an area of ​​one circumference of the tread portion in the tire circumferential direction.

4. 3. The system for measuring forces acting on a tire contact patch according to claim 2, wherein the tread surface area is an area of ​​one circumference of the tread portion in the tire circumferential direction and the tire axial direction.

5. Further comprising a drum rotation position detection unit for detecting the rotation position of the drum, the drum rotation position detection unit detects the rotation position of the drum in a drum circumferential direction in third length units, 3. The system for measuring a force acting on a tire contact patch according to claim 1, wherein the third length is equal to or less than half of the first length.

6. the detection surface has a fourth length in the drum width direction, 3. The system for measuring a force acting on a tire contact patch according to claim 1, wherein the second length is equal to or less than half of the fourth length.

7. 3. The system for measuring forces acting on a tire contact patch according to claim 1, wherein the data processing unit further includes an image generation unit that generates, based on the force data, an image of a distribution of forces acting on the contact patch to be displayed on a display device.

8. A measurement method for measuring the force acting on the contact surface of a tire tread, comprising: a force detection step of measuring a force acting on the contact surface of the tire running on a running surface of a cylindrical drum; a tire rotational position detection step for detecting a rotational position of the tire traveling on the traveling surface; a data processing step for receiving and processing the data obtained in the force detection step and the tire rotational position detection step, the force detecting step outputs force data within a range of a first length in a drum circumferential direction; the tire rotational position detecting step detects the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing step includes: storing the force data for the first length range obtained in the force detecting step in a data storage area in units of the second length; When the force data is stored a plurality of times at the same tire rotation position stored in the data storage area, the force data stored a plurality of times is averaged. A method for measuring the force acting on the tire's contact surface.

9. A measurement program for measuring a force acting on a contact surface of a tire tread, a force detection step of measuring a force acting on the contact surface of the tire running on a running surface of a cylindrical drum; a tire rotational position detection step for detecting a rotational position of the tire traveling on the traveling surface; a data processing step for receiving and processing the data obtained in the force detection step and the tire rotational position detection step, the force detecting step outputs force data within a range of a first length in a drum circumferential direction; the tire rotational position detecting step detects the rotational position of the tire in a tire circumferential direction in units of a second length that is smaller than the first length, The data processing step includes: storing the force data for the first length range obtained in the force detecting step in a data storage area in units of the second length; When the force data is stored a plurality of times at the same tire rotation position stored in the data storage area, the force data stored a plurality of times is averaged. A program for measuring the forces acting on the tire's contact surface.

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