JP6520058B2 - Pneumatic tire and vehicle - Google Patents

Description

  The present invention relates to a pneumatic tire and a vehicle.

  In the technical field related to automobiles, a collision avoidance system has been put into practical use that detects the distance between a preceding vehicle and a subsequent vehicle to avoid a collision between vehicles. As a method of detecting the distance between vehicles, a method using a millimeter wave sensor, a method using a radar sensor, and a method using a camera are known. Patent Document 1 and Patent Document 2 disclose techniques for estimating the distance between a preceding vehicle and a following vehicle using an image acquired by a camera. Patent Document 1 discloses a technique for estimating the distance to a preceding vehicle using a series of images recorded by a single-eye camera. Patent Document 2 describes a technique for extracting left and right tail lamps or tires of a preceding vehicle as feature points from an image acquired by a digital camera and estimating a distance between the vehicles based on a distance between the feature points. It is done.

U.S. Patent No. 8164628 JP 2013-101040

  In order to avoid collisions between vehicles, it is effective to grasp the traveling speed of the vehicles followed by the following vehicles. The method using the millimeter wave sensor and the method using the radar sensor can estimate the traveling speed of the vehicle. It is desirable to devise a technology that can estimate the traveling speed of a vehicle using an inexpensive monocular camera.

  An aspect of the present invention is to provide a pneumatic tire in which the speed of a preceding vehicle is estimated using an image acquired by a camera mounted on the vehicle, and a collision between the vehicles can be suppressed. Another object of the present invention is to provide a vehicle capable of suppressing a collision.

  According to a first aspect of the present invention, there is provided a pneumatic tire having a surface and rotatable about a central axis, wherein the surface is a ground color area including a surface of rubber, and a circumference of the central axis. And a first belt area for velocity measurement having a plurality of colored areas intermittently provided in a direction.

  According to a first aspect of the present invention, there is provided a first belt area for velocity measurement having a plurality of intermittently provided colored areas. The camera of the following vehicle acquires an image of the pneumatic tire at a predetermined frame rate. Therefore, based on the frame rate and the image of the first belt area obtained at each frame rate, the rotational speed of the pneumatic tire mounted on the host vehicle is estimated. The traveling speed of the host vehicle is estimated by estimating the rotational speed of the pneumatic tire. This suppresses the collision of the following vehicle with the host vehicle.

  In the first aspect of the present invention, the reflectance of the colored region to visible light may be higher than the reflectance of the ground color region.

  Thereby, the colored area is recognized by the camera at a high recognition rate. For example, even at nighttime rainfall, the colored area is recognized by the camera at a high recognition rate. The reflectance is the "total light reflectance" measured by the method specified in JIS K-7375.

  In the first aspect of the present invention, a shoulder portion may be provided, and the first belt region may be provided on the surface of the shoulder portion.

  As a result, the contact between the colored area of the first belt area and the road surface is suppressed. Therefore, the colored area lasts longer. In addition, when the pneumatic tire is mounted on the vehicle, not only the camera of the vehicle behind the just behind but also the camera of the vehicle behind the right behind and the vehicle behind the left behind The pneumatic tire of the host vehicle is also recognized at a high recognition rate by the camera of the vehicle.

  In the first aspect of the present invention, the dimensions of the plurality of colored regions may be different with respect to the circumferential direction.

  As a result, even if the pneumatic tire rotates at high speed, the first belt area is recognized by the camera of the following vehicle with a high recognition rate.

  In the first aspect of the present invention, the surface may further include a second belt region for identifying unique information having a plurality of colored regions intermittently provided in the circumferential direction of the central axis.

  As a result, the camera acquires the image of the second belt region functioning as a bar code, whereby the unique information of the pneumatic tire mounted on the host vehicle is recognized by the following vehicle.

  In the first aspect of the present invention, the surface may further include a third belt region for image recognition having a colored region provided in the circumferential direction of the central axis.

  As a result, the decrease in the recognition rate of the pneumatic tire mounted on the host vehicle is suppressed, and the collision of the following vehicle with the host vehicle is suppressed. The colored area of the third belt area for image recognition is colored in a color that enables image recognition at a high recognition rate. Since the third belt region is provided, the decrease in the recognition rate of the pneumatic tire mounted on the host vehicle by the camera of the following vehicle is suppressed. This suppresses the collision of the following vehicle with the host vehicle. In addition, the colored area of the third belt area is provided in the circumferential direction. Therefore, even while the host vehicle on which the pneumatic tire is mounted is traveling, the colored area of the third belt area of the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle with a high recognition rate. Also, the pneumatic tire comes in contact with the road surface. In other words, the distance between the road surface and the pneumatic tire is short. Since the pneumatic tire is disposed at a position close to the road surface, even if the image of the pneumatic tire projected on the wet road surface is acquired by the camera, the host vehicle is based on the image of the pneumatic tire projected on the road surface The error in the estimation result of the distance to the following vehicle is suppressed. As a result, the decrease in the recognition rate of the pneumatic tire mounted on the host vehicle is suppressed, and the collision of the following vehicle with the host vehicle is suppressed.

  In addition, image recognition is analyzing the structure of the image of the pneumatic tire acquired with the camera, extracting a feature point, and performing a pneumatic tire recognition. The recognition rate is a value indicated by “(total image number−false recognition number) / total image number” when the camera acquires a plurality of images of the pneumatic tire. Image recognition includes processing such as extraction of image features and correspondence between image features and pneumatic tires (pattern matching).

  In the first aspect of the present invention, the dimension of the colored area of the first belt area may be 5 mm or more in the direction parallel to the central axis.

  Thereby, the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle with a high recognition rate.

  In the first aspect of the present invention, the colored area may include the surface of a paint applied to the rubber.

  This enhances the freedom of choice of materials and easily provides colored areas with the desired reflectivity, the desired brightness and the desired contrast to the background area.

  In the first aspect of the present invention, the paint may include a fluorescent paint.

  As a result, the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle at a high recognition rate even at night or when it is raining.

  In the first aspect of the present invention, the paint may include a retroreflective material.

  Thereby, the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle with a high recognition rate.

  In the first aspect of the present invention, it may include a colored rubber containing a colorant, and the colored region may include the surface of the colored rubber.

  Thereby, a pneumatic tire having a colored area is easily manufactured.

  According to a second aspect of the present invention, there is provided a vehicle comprising: a plurality of wheels; and the pneumatic tire according to the first aspect attached to at least the rearmost one of the plurality of wheels. .

  According to the second aspect of the present invention, a vehicle (self-vehicle) in which a pneumatic tire is mounted on the rearmost wheel is recognized by the camera of the following vehicle with a high recognition rate. Therefore, the traveling speed of the host vehicle is smoothly grasped by the following vehicle. Therefore, the collision of the host vehicle with the following vehicle is suppressed.

  In the second aspect of the present invention, an illumination device for illuminating the pneumatic tire mounted on the last wheel may be provided.

  Thereby, for example, at night, the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle with a high recognition rate.

  According to an aspect of the present invention, the speed of a preceding vehicle is estimated using an image acquired by a camera mounted on the vehicle, and a pneumatic tire capable of suppressing a collision between vehicles is provided. Further, according to an aspect of the present invention, a vehicle capable of suppressing a collision is provided.

FIG. 1 is a cross-sectional view showing an example of the pneumatic tire according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of a portion of the pneumatic tire according to the first embodiment. FIG. 3 is a view showing an example of a tread portion of the pneumatic tire according to the first embodiment. FIG. 4 is an enlarged view of a portion B of FIG. 3. FIG. 5 is a developed view showing an example of the first belt area according to the first embodiment. FIG. 6 is a developed view showing an example of the first belt area according to the first embodiment. FIG. 7 is a developed view showing an example of the first belt area according to the first embodiment. FIG. 8 is a developed view showing an example of the first belt area according to the first embodiment. FIG. 9 is a view showing an example of a vehicle equipped with the pneumatic tire according to the first embodiment. FIG. 10 is a developed view showing an example of a pneumatic tire according to a second embodiment. FIG. 11 is a view showing an example of a vehicle equipped with the pneumatic tire according to the third embodiment. FIG. 12 is a view schematically showing an example of the relationship between the host vehicle and the following vehicle according to the comparative example. FIG. 13 is a view schematically showing an example of the relationship between the host vehicle and the following vehicle according to the third embodiment. FIG. 14 is a view showing an example of a tread portion of a pneumatic tire according to a fourth embodiment. FIG. 15 is a view showing an example of a tread portion of a pneumatic tire according to a fifth embodiment. FIG. 16 is a view for explaining an example of the first belt area according to the sixth embodiment. FIG. 17 is a view showing an example of a vehicle according to the seventh embodiment. FIG. 18 is a schematic diagram for explaining the relationship between the preceding vehicle, the own vehicle, and the following vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

  In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. One direction in the horizontal plane is taken as an X-axis direction, a direction orthogonal to the X-axis direction in a horizontal plane is taken as a Y-axis direction, and a direction orthogonal to each of the X-axis direction and the Y-axis direction is taken as a Z-axis direction. Further, rotation (inclination) directions around the X axis, the Y axis, and the Z axis are taken as θX, θY, and θZ directions, respectively.

First Embodiment
The first embodiment will be described. FIG. 1 is a cross-sectional view showing an example of a pneumatic tire 1 according to the present embodiment. FIG. 2 is a cross-sectional view enlarging a part of the pneumatic tire 1 according to the present embodiment. In the following description, the pneumatic tire 1 is appropriately referred to as a tire 1.

  The tire 1 is rotatable about a central axis (rotational axis) AX. 1 and 2 each show a meridional section passing through the central axis AX of the tire 1. The central axis AX of the tire 1 is orthogonal to the equatorial plane CL of the tire 1.

  In the present embodiment, the central axis AX of the tire 1 and the Y axis are parallel. That is, in the present embodiment, the direction parallel to the central axis AX is the Y-axis direction. The Y-axis direction is the width direction or the vehicle width direction of the tire 1. The equatorial plane CL passes through the center of the tire 1 in the Y-axis direction. The θY direction is the rotational direction of the tire 1 (central axis AX). The X-axis direction and the Z-axis direction are radial directions with respect to the central axis AX. The road surface (ground) on which the tire 1 travels (rolls) is substantially parallel to the XY plane.

  In the following description, the rotational direction of the tire 1 (central axis AX) is appropriately referred to as circumferential direction, the radial direction with respect to the central axis AX is appropriately referred to as radial direction, and the direction parallel to the central axis AX is appropriately width It is called direction.

  The tire 1 includes a carcass portion 2, a belt layer 3, a belt cover 4, a bead portion 5, a tread portion 10 and a sidewall portion 9. The tread portion 10 includes a tread rubber 6. The sidewall portion 9 includes sidewall rubber 8. Each of the carcass portion 2, the belt layer 3 and the belt cover 4 includes a cord. The cord is a reinforcement. The cord may be referred to as a wire. Each of the layers including a reinforcing material such as the carcass portion 2, the belt layer 3, and the belt cover 4 may be referred to as a cord layer or may be referred to as a reinforcing material layer.

  The carcass portion 2 is a strength member that forms the skeleton of the tire 1. The carcass part 2 contains a code. The cord of the carcass part 2 may be referred to as a carcass cord. The carcass portion 2 functions as a pressure vessel when the tire 1 is filled with air. The carcass portion 2 is supported by the bead portion 5. The bead portion 5 is disposed on one side and the other side of the carcass portion 2 in the Y-axis direction. The carcass portion 2 is folded back at the bead portion 5. The carcass portion 2 includes a carcass cord of organic fiber and a rubber covering the carcass cord. The carcass portion 2 may include a polyester carcass cord, a nylon carcass cord, an aramid carcass cord, or a rayon carcass cord.

  The belt layer 3 is a strength member that holds the shape of the tire 1. The belt layer 3 contains a cord. The cord of the belt layer 3 may be referred to as a belt cord. The belt layer 3 is disposed between the carcass portion 2 and the tread rubber 6. The belt layer 3 includes, for example, a belt cord of metal fiber such as steel and a rubber covering the belt cord. The belt layer 3 may include a belt cord of organic fiber. In the present embodiment, the belt layer 3 includes a first belt ply 3A and a second belt ply 3B. The first belt ply 3A and the second belt ply 3B are stacked so that the cord of the first belt ply 3A and the cord of the second belt ply 3B intersect.

  The belt cover 4 is a strength member that protects and reinforces the belt layer 3. The belt cover 4 includes a cord. The cord of the belt cover 4 may be referred to as a cover cord. The belt cover 4 is disposed outside the belt layer 3 with respect to the central axis AX of the tire 1. The belt cover 4 includes, for example, a cover cord of metal fiber such as steel and a rubber covering the cover cord. The belt cover 4 may include a cover cord of organic fiber.

  The bead portion 5 is a strength member that fixes both ends of the carcass portion 2. The bead portion 5 fixes the tire 1 to the rim. The bead portion 5 is a bundle of steel wires. The bead portion 5 may be a bundle of carbon steel.

  The tread rubber 6 protects the carcass portion 2. The tread rubber 6 has a tread portion 10 and a plurality of grooves 20 provided in the tread portion 10. The tread portion 10 includes a contact portion that comes in contact with the road surface. The tread portion 10 includes land portions disposed between the grooves 20.

  The sidewall rubber 8 protects the carcass portion 2. The sidewall rubber 8 is disposed on one side and the other side of the tread rubber 6 in the Y-axis direction. The sidewall rubber 8 has sidewall portions 9 disposed on one side and the other side of the tread portion 10 in the Y-axis direction.

  In the present embodiment, the tire outer diameter is OD. The tire rim diameter is RD. The tire total width is SW. The tread contact width is W. The tread spread width is TDW.

  The tire outer diameter OD is the diameter of the tire 1 when no load is applied to the tire 1 in a state where the tire 1 is mounted on the prescribed rim and the tire 1 is rim-assembled on the regular rim and filled with the regular internal pressure. Say.

  The tire rim diameter RD refers to the rim diameter of the wheel that fits the tire 1. The tire rim diameter RD is equal to the tire inner diameter.

  The tire total width SW is the maximum dimension of the tire 1 in a direction parallel to the central axis AX when no load is applied to the tire 1 in a state where the tire 1 is rim-assembled to a normal rim and filled with a regular internal pressure. Say. That is, the tire total width SW is a portion on the + Y side of the sidewall portion 9 disposed on the + Y side of the tread rubber 6 and a portion on the −Y side of the sidewall portion 9 disposed on the -Y side. Say the distance. When a structure protruding from the surface of the side wall portion 9 is provided on the surface of the side wall portion 9, the total tire width SW means the maximum dimension of the tire 1 in the Y-axis direction including the structure. . The structure protruding from the surface of the sidewall portion 9 includes at least one of characters, marks, and patterns formed by at least a portion of the sidewall rubber 8 in the sidewall portion 9.

  In the present embodiment, the tread contact width W is the center of the tire 1 measured when a normal load is applied by placing the tire 1 vertically on a flat surface with the tire 1 rimmed and filled with a regular internal pressure. The maximum value of the contact width in the direction parallel to the axis AX.

  In the present embodiment, the tread development width TDW is a straight line at both ends in the development view of the tread portion 10 of the tire 1 when no load is applied in a state where the tire 1 is rim-assembled to a normal rim and filled with normal internal pressure. I say the distance.

  The “regular rim” is a rim that defines the standard for each tire 1 in the standard system including the standard on which the tire 1 is based, for example, a standard rim for JATMA, “Design Rim” for TRA, Or if it is ETRTO, it will be "Measuring Rim". However, when the tire 1 is a new car mounted tire, a genuine wheel on which the tire is assembled is used.

  The “normal internal pressure” is the air pressure specified in each tire 1 in the standard system including the standard to which the tire 1 is based, and in the case of JATMA, the maximum air pressure, in the case of TRA, the table “TIRE ROAD LIMITS In the case of ETRTO, the maximum value described in "AT VARIOUS COLD INFlation PRESSURES" is "INFLATION PRESSURE". However, when the tire 1 is a new car-mounted tire, the air pressure displayed on the vehicle is used.

  The “normal load” is a load defined in each tire 1 in the standard system including the standard to which the tire 1 is based, and in the case of JATMA, the maximum load capacity, in the case of TRA, the table “TIRE ROAD In the case of ETRTO, the maximum value described in LIMITS AT VARIOUS COLD INFlation PRESSURES is “LOAD CAPACITY”, but when the tire 1 is a passenger car, the load corresponds to 88% of the load. When the tire 1 is a new car mounted tire, the front and rear axle weights described in the vehicle verification of the vehicle are divided by the number of tires to obtain the wheel load.

  FIG. 3 is a view showing an example of the tread portion 10 of the tire 1. FIG. 4 is an enlarged view of a portion B of FIG. 3. As shown in FIG. 2, FIG. 3 and FIG. 4, the tire 1 has a tread portion 10. The tread portion 10 includes a center portion 11 and shoulder portions 12 disposed on both sides of the center portion 11 in the Y-axis direction.

  The tire 1 has a groove 20 provided in the tread portion 10. The groove 20 includes a main groove 21 extending in the circumferential direction of the tire 1 and a lug groove (lateral groove) 22 at least a portion of which extends in the width direction of the tire 1. A land portion is provided around the groove 20. The land portion is provided between the groove 20 and the groove 20 adjacent to the groove 20. The tread portion 10 includes a plurality of land portions.

  The main groove 21 is provided in the circumferential direction of the tire 1. At least a portion of the main groove 21 is provided in the center portion 11 of the tread portion 10. The main groove 21 has a treadwear indicator inside. The treadwear indicator indicates the end of wear. The main groove 21 has a width of 4.0 mm or more, and may have a depth of 5.0 mm or more. In the example shown in FIGS. 2 and 3, the tire 1 has four main grooves 21.

  At least a part of the lug groove 22 is provided in the width direction of the tire 1. At least a portion of the lug groove 22 is provided in the shoulder portion 12 of the tread portion 10. The shoulder portion 12 is disposed on one side (+ Y side) and the other side (−Y side) of the center portion 11 in the width direction (Y-axis direction). The lug grooves 22 have a width of 1.5 mm or more. The lug grooves 22 may have a depth of 4.0 mm or more, and may partially have a depth of less than 4.0 mm.

  In the present embodiment, the colored area 7 is provided on at least a part of the surface of the tire 1. In the present embodiment, the surface of the tire 1 includes the surface of the tread portion 10 and the surface of the sidewall portion 9. The surface of the tread portion 10 includes the surface of the center portion 11, the surface of the shoulder portion 12, and the inner surface of the groove 20.

  The colored area 7 is provided on part of the surface of the tire 1. The surface of the tire 1 other than the colored area 7 is a ground color area 13. The color of the ground color area 13 is the color of the base relative to the colored area 7. The ground color area 13 includes the rubber surface of the tire 1 including the tread rubber 6 and the sidewall rubber 8. The color of the ground color area 13 is the color of the rubber. The surface of the tire 1 includes a ground color area 13 including a surface of rubber and a colored area 7 of a color different from the color of the ground color area 13. A colored area 7 is formed by coloring the base of the tire 1 such as rubber.

  In the present embodiment, a plurality of colored regions 7 are provided intermittently in the circumferential direction of the central axis AX (tire 1). In the following description, a belt region having a plurality of colored regions 7 intermittently provided in the circumferential direction of the central axis AX will be referred to as a first belt region 31 as appropriate.

  The first belt region 31 is a belt region for velocity measurement having a plurality of colored regions 7 provided intermittently in the circumferential direction of the central axis AX.

  The colored area 7 is an area for image recognition. An image of the tire 1 is acquired by the camera. The color of the colored area 7 is a color that enables the camera to perform image recognition at a high recognition rate.

  In addition, image recognition is analyzing the structure of the image of the tire 1 acquired with the camera, extracting a feature point, and performing tire 1 recognition. The recognition rate refers to a value indicated by “(total image number−false recognition number) / total image number” when the camera acquires a plurality of images of the tire 1. Image recognition includes processing such as extraction of an image feature and correspondence (pattern matching) between the image feature and the tire 1.

  The reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13 to visible light. The color of the ground color area 13 is black. The color of the colored area 7 is, for example, at least one of yellow, beige, brown, red, green, blue, gray and white. In addition, the reflectance of the surface (colored area 7 or ground color area 13) of the tire 1 here means the reflectance of a color diffusion surface. In the present embodiment, the reflectance is “total light reflectance” measured by the method prescribed in JIS K-7375.

  As shown in JIS Z 8721-1993, when the Munsell brightness is high, the reflectance is high. Therefore, the color of the colored area 7 and the color of the ground color area 13 may be the same, and the lightness (Muncel lightness) may be different. That is, the lightness of the colored area 7 may be adjusted with respect to the lightness of the ground color area 13 so that the reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13.

  Since the reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13 to visible light, the colored area 7 is recognized by the camera with a high recognition rate.

  As shown in FIGS. 3 and 4, in the present embodiment, the first belt region 31 is provided on the surface of the shoulder portion 12.

  The surface of the shoulder portion 12 is an end portion (grounding end portion) 60 of the ground contact region of the tread portion 10 in the Y-axis direction and an end portion 70 of the lug groove 22 disposed outside the ground end portion 60 in the Y-axis direction. And the surface of the tire 1 between. In the following description, a region between the ground end 60 and the end 70 of the surface of the shoulder 12 is appropriately referred to as a shoulder region AR.

  In the present embodiment, the first belt area 31 including the colored area 7 is provided in the shoulder area AR. Colored region 7 is provided intermittently in the circumferential direction in shoulder region AR.

  The ground contact end 60 refers to an edge portion of the tread contact width W. As described above, the tread contact width W is a center axis AX measured when a tire 1 is rimmed on a regular rim and placed on a plane in a normal state filled with a regular internal pressure and a regular load is applied The maximum value of the contact width in the parallel direction.

  The shoulder portions 12 (shoulder regions AR) are disposed on both sides of the center portion 11 in the Y-axis direction. The first belt region 31 may be provided on the shoulder portions 12 on both sides of the center portion 11 or may be provided on any one of the shoulder portions 12.

  FIG. 5 is a developed view in which the tread portion 10 is developed in the circumferential direction. FIG. 5 shows an example in which the colored area 7 (first belt area 31) is provided in one of the two shoulder areas AR.

  In the example shown in FIG. 5, four colored areas 7 are provided intermittently in the circumferential direction. In the circumferential direction, the dimensions La of the plurality of colored areas 7 are equal. A blank area 25 is provided between adjacent colored areas 7. The blank area 25 includes a ground color area 13. A plurality of blank areas 25 are provided intermittently in the circumferential direction. With respect to the circumferential direction, the dimensions Lb of the plurality of blank areas 25 are equal.

  FIG. 6 is a developed view in which the tread portion 10 is developed in the circumferential direction. FIG. 6 shows an example in which the colored area 7 (first belt area 31) is provided in one of the two shoulder areas AR.

  FIG. 6 shows another example of the first belt area 31. In the example shown in FIG. 6, four colored areas 7 are provided intermittently in the circumferential direction. With respect to the circumferential direction, the dimensions La of the plurality of colored regions 7 are different from one another. A blank area 25 is provided between adjacent colored areas 7. With respect to the circumferential direction, the dimensions Lb of the plurality of blank regions 25 are different from one another.

  7 and 8 show another example of the first belt area 31. FIG. In the example shown in FIGS. 7 and 8, the colored area 7 of the first belt area 31 is provided not only at the shoulder portion 12 but also at the center portion 11. The plurality of colored regions 7 are disposed in each of the circumferential direction and the width direction of the tire 1. In the example shown in FIG. 7, the first belt area 31 has two groups 31A in which the position of the colored area 7 in the width direction of the tire 1 gradually changes from one side to the other side in the width direction. In the example shown in FIG. 8, in the first belt area 31, the position of the colored area 7 in the width direction of the tire 1 gradually changes from one side to the other side with the group 31A in which the position gradually changes from one side to the other side. And a group 31B that changes to

  In the present embodiment, the dimension of the colored area 7 of the first belt area 31 is 5 mm or more in the Y-axis direction. The dimension of the colored area 7 of the first belt area 31 may be 7 mm or more in the Y-axis direction.

  In the present embodiment, the colored area 7 includes the surface of the paint applied to the base rubber. That is, in the present embodiment, the colored region 7 is provided by applying the paint to the surface of the rubber of the tire 1 which is the base. In the present embodiment, the paint is applied to a region of the surface of the tread rubber 6 corresponding to the shoulder portion 12. Thereby, the colored region 7 is provided in the shoulder portion 12.

  In the present embodiment, a paint having a reflectance to visible light higher than that of rubber (tread rubber 6) is applied. The color or Munsell brightness of the paint is selected such that the reflectance to visible light is higher than that of rubber.

  The paint may be a fluorescent paint. The fluorescent paint refers to a paint using a phosphor as a pigment. The phosphor contained in the fluorescent paint is stimulated by ultraviolet light to emit fluorescence.

  The paint may be a luminous paint. A luminous paint refers to a paint which has a phosphor or phosphor as a main pigment which has the property of receiving electromagnetic waves of a short wavelength shorter than visible light or ultraviolet light and changing its energy into visible light. The luminous paint may be a luminous paint or a luminous paint.

  The paint may also contain a diffusible material. The diffusive material includes metal particles or glass particles.

  The paint may include a retroreflective material. That is, the paint may be a so-called retroreflective paint. The retroreflective material is made of a transparent resin layer including spherical and transparent reflective beads in which a reflective film is formed on part of the surface.

  FIG. 9 is a view showing an example of a vehicle 100 on which the tire 1 having the first belt region 31 is mounted. FIG. 9 is a view of the vehicle 100 as viewed from the rear. As shown in FIG. 9, the vehicle 100 has a vehicle body 14, a tail lamp 18 disposed at a rear portion 14 </ b> R of the vehicle body 14, and the tire 1.

  Vehicle 100 has a plurality of wheels. In the present embodiment, the vehicle 100 is a four-wheeled vehicle having four wheels. Vehicle 100 has a front wheel and a rear wheel. As shown in FIG. 9, the tire 1 is attached to at least the rearmost wheel (rear wheel in this example).

  The tire 1 according to the present embodiment is mounted on a vehicle (own vehicle) 100 preceding a road surface. A vehicle following the vehicle 100 (following vehicle) has a collision avoidance system for avoiding a collision (a rear-end collision) with the host vehicle 100. A camera for acquiring an image of the host vehicle 100 is mounted on the following vehicle. The camera acquires an image of the vehicle 100. The collision avoidance system of the following vehicle estimates the traveling speed of the own vehicle 100 from the image of the own vehicle 100 acquired by the camera.

  In the present embodiment, the first belt region 31 is provided in the tire 1 mounted on the host vehicle 100. The first belt region 31 has a plurality of colored regions 7 provided intermittently in the circumferential direction (rotational direction of the tire 1). The camera of the following vehicle acquires the image of the tire 1 of the host vehicle 100 at a predetermined frame rate (predetermined period). When an image of the running (rolling) tire 1 is acquired by the camera, an image of the first belt area 31 acquired at each frame rate is different. That is, when an image of the running (rolling) tire 1 is acquired by the camera, the position of the colored area 7 of the first belt area 31 in the visual field of the camera acquired at the first frame rate (or Position and area of the colored area occupying the visual field area, and the position (or camera) of the colored area 7 of the first belt area 31 in the visual field area of the camera obtained at the second frame rate next to the first frame rate The position and area of the colored area occupied in the visual field area of

  Therefore, the rotational speed of the tire 1 mounted on the host vehicle 100 is estimated based on the frame rate (period) at which an image is acquired and the image of the first belt area 31 acquired at each frame rate. By estimating the rotational speed of the tire 1, the traveling speed of the host vehicle 100 is estimated. As described above, in the present embodiment, the first belt area 31 of the tire 1 mounted on the vehicle 100 is rotated by the camera (single-eye camera) of the following vehicle 200 and the traveling speed of the vehicle 100. Functions as a belt area for speed measurement (for speed estimation) to be measured (estimated).

  As described above, according to the present embodiment, the tire 1 is provided with the first belt region 31 for speed measurement having the plurality of colored regions 7 provided intermittently. The camera of the following vehicle acquires an image of the tire 1 at a predetermined frame rate. Therefore, based on the frame rate and the image of the first belt area 31 acquired at each frame rate, the rotational speed of the tire 1 mounted on the host vehicle 100 is estimated. By estimating the rotational speed of the tire 1, the traveling speed of the host vehicle 100 is estimated. As a result, the collision of the following vehicle with the host vehicle 100 is suppressed.

  Further, according to the present embodiment, the reflectance of the colored region 7 to visible light is higher than the reflectance of the ground color region 13. Thereby, the colored area 7 is recognized by the camera at a high recognition rate. For example, even at nighttime rainfall, the colored area 7 is recognized by the camera at a high recognition rate.

  Further, according to the present embodiment, the first belt region 31 is provided on the surface of the shoulder portion 12 of the tire 1. As a result, the contact between the colored area 7 of the first belt area 31 and the road surface is suppressed. Therefore, the colored area 7 lasts long. When the tire 1 is mounted on the vehicle 100, not only the camera of the vehicle behind the just behind but also the camera of the vehicle behind the right behind and the vehicle behind the left behind The pneumatic tire of the host vehicle is also recognized at a high recognition rate by the camera of the vehicle.

  Further, as shown in FIG. 6, the dimensions La of the plurality of colored areas 7 may be different in the circumferential direction. By arranging the plurality of colored areas 7 at unequal lengths and unequal intervals, the camera of the following vehicle detects the area of the tire 1 based on the image of the first belt area 31 even if the tire 1 rotates at high speed. The rotational speed can be accurately estimated.

  Further, as shown in FIG. 7 and FIG. 8, the plurality of colored regions 7 are arranged so that the positions of the colored regions 7 are different not only in the circumferential direction but also in the width direction, so that the tire 1 has high speed Even if it rotates, the difference between the image of the first frame rate and the image of the second frame rate is likely to occur. Therefore, even if the tire 1 rotates at a high speed, the camera of the following vehicle can accurately estimate the rotational speed of the tire 1 based on the image of the first belt region 31. In particular, as shown in FIG. 8, when the groups 31A and 31B are provided, the tire 1 can be more responsive to high-speed rotation.

  Further, in the first embodiment of the present invention, the dimension of the colored area of the first belt area may be 5 mm or more in the direction parallel to the central axis.

  Thereby, the pneumatic tire of the host vehicle is recognized by the camera of the following vehicle with a high recognition rate.

  Further, in the present embodiment, the colored area 7 includes the surface of the paint applied to the rubber that is the base of the tire 1. The rubber that is the base of the tire 1 includes one or both of the tread rubber 6 and the sidewall rubber 8. This increases the freedom of material selection. Therefore, for example, it is possible to easily provide a colored area 7 with a desired reflectance, a colored area 7 with a desired color, a colored area 7 with a desired brightness, and a colored area 7 with a desired contrast to the ground color area 13 .

  In the present embodiment, the paint may include a fluorescent paint. Thereby, even at night or at the time of rainfall, the camera 201 of the following vehicle 200 can recognize the tire 1 of the own vehicle 100 at a high recognition rate.

  In the present embodiment, the paint may include a retroreflective material. Thereby, the camera 201 of the following vehicle 200 can recognize the tire 1 of the own vehicle 100 at a high recognition rate.

  In the present embodiment, the colored area 7 of the first belt area 31 is provided in the shoulder portion 12. For example, the colored area 7 of the first belt area 31 may be provided on the inner surface of the main groove 21. Also in this case, the colored area 7 of the first belt area 31 is prevented from contacting the road surface, and the colored area 7 can be made to last longer.

Second Embodiment
The second embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  FIG. 10 is a view showing an example of a tire 1 according to the present embodiment. FIG. 10 shows a developed view of the tread portion 10 of the tire 1. In the present embodiment, the surface of the tire 1 further includes a second belt region 32 for identifying unique information having a plurality of colored regions 7 provided intermittently in the circumferential direction of the central axis AX.

  In the example shown in FIG. 10, the second belt region 32 is provided in the shoulder portion 12 (shoulder region AR). The second belt region 32 may be provided in the center portion 11.

  The plurality of colored areas 7 of the second belt area 32 form an identification pattern. The second belt region 32 provided in the tire 1 includes the unique information of the tire 1. The second belt area 32 including the plurality of colored areas 7 functions as a barcode.

  The camera of the following vehicle acquires an image of the second belt area 32 and acquires unique information of the tire 1. The camera of the following vehicle acts as a bar code reader.

  The specific information of the tire 1 includes at least one of the outer diameter of the tire 1, the circumferential length of the tire 1, and the type of the tire 1. The types of tire 1 include types of studless tires, all-season tires, winter tires, and summer tires. The second belt region 32 may include unique information of the vehicle 100, such as the entire length and the entire width of the vehicle 100.

  The camera of the following vehicle acquires an image of the first belt area 31 and an image of the second belt area 32. Based on the image of the first belt area 31, the rotational speed of the tire 1 is estimated. By acquiring information on the outer diameter or circumferential length of the tire 1 based on the image of the second belt region 32, the vehicle 100 is obtained based on the rotational speed of the tire 1 and the outer diameter or circumferential length of the tire 1. The traveling speed of can be estimated more accurately.

  As described above, according to the present embodiment, an image of the second belt region 32 functioning as a bar code is acquired by the camera of the following vehicle, whereby the unique information of the tire 1 mounted on the host vehicle 100 is obtained. Recognized by the following vehicle.

Third Embodiment
A third embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  FIG. 11 is a rear view of a vehicle 100 equipped with the tire 1 according to the present embodiment. In the present embodiment, the surface of the tire 1 further includes a third belt region 33 for image recognition having a colored region 7 provided in the circumferential direction of the central axis AX.

  The colored area 7 of the third belt area 33 is an area for image recognition. An image of the tire 1 is acquired by the camera. The color of the colored area 7 is a color that enables the camera to perform image recognition at a high recognition rate.

  In addition, image recognition is analyzing the structure of the image of the tire 1 acquired with the camera, extracting a feature point, and performing tire 1 recognition. The recognition rate refers to a value indicated by “(total image number−false recognition number) / total image number” when the camera acquires a plurality of images of the tire 1. Image recognition includes processing such as extraction of an image feature and correspondence (pattern matching) between the image feature and the tire 1.

  The reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13 to visible light. Since the reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13 to visible light, the colored area 7 is recognized by the camera with a high recognition rate. In the present embodiment, the reflectance is “total light reflectance” measured by the method prescribed in JIS K-7375.

  In the present embodiment, the colored regions 7 are provided in the circumferential direction. The colored area 7 is disposed around the central axis AX. In other words, the colored regions 7 are provided continuously in the circumferential direction without interruption. The colored area 7 may be arranged in part of the periphery of the central axis AX.

  In the present embodiment, the third belt region 33 is provided on the surface of the shoulder portion 12. In the example shown in FIG. 11, at least a part of the first belt region 31 is provided in the center portion 11.

  FIG. 12 is a schematic view showing an example of the relationship between a vehicle (own vehicle) 100 preceding a road surface and a vehicle (following vehicle) 200 following the vehicle 100. As shown in FIG. FIG. 12 is a diagram according to a comparative example. The following vehicle 200 has a collision avoidance system for avoiding a collision (a rear-end collision) with the host vehicle 100. In the following vehicle 200, a camera 201 for acquiring an image of the host vehicle 100 is mounted. The collision avoidance system of the following vehicle 200 extracts the feature points of the own vehicle 100 from the image of the own vehicle 100 acquired by the camera 201, and based on the extracted feature points, the following vehicle 200 and the following vehicle 200 are Estimate the distance.

  FIG. 12 shows an example in which the tail lamp 18 of the host vehicle 100 is extracted as the feature point of the host vehicle 100. With respect to the height direction, the position of the tail lamp 18 is separated from the position of the road surface.

  An actual image (real image) IMa of the tail lamp 18 of the own vehicle 100 is acquired by the camera 201 of the following vehicle 200. Thus, the collision avoidance system of the following vehicle 200 can recognize the own vehicle 100 and estimate the distance between the own vehicle 100 and the following vehicle 200.

  When the tail lamp 18 of the vehicle 100 is extracted as a feature point, for example, when it is raining, the recognition rate of the vehicle 100 by the camera 201 may be reduced. As shown in FIG. 12, the tail lamp 18 is separated from the road surface in the height direction. In the case where the tail lamp 18 of the vehicle 100 is extracted as a feature point, if the road surface is wet due to rain, the camera 201 is more likely to acquire the image IMb of the tail lamp 18 projected on the road surface. If the distance between the subject vehicle 100 and the following vehicle 200 is estimated based on the image IMb of the tail lamp 18 projected on the road surface instead of the actual image IMa of the tail lamp 18, the reliability of the estimation result may be reduced. is there. In particular, at nighttime rainfall, the recognition rate of the vehicle 100 by the camera 201 may be significantly reduced.

  That is, when a portion having a large distance to the road surface in the height direction is extracted as a feature point, the optical path length of the image IMa from the characteristic point (tail lamp 18 in this example) to the camera 201 The difference between As a result, the reliability of the estimation result of the distance between the own vehicle 100 and the following vehicle 200 may be reduced.

  FIG. 13 is a schematic view showing an example of the relationship between the vehicle 100 equipped with the tire 1 according to the present embodiment and the following vehicle 200 equipped with the camera 201. FIG. 13 shows an example in which the tire 1 of the host vehicle 100 is extracted as a feature point of the host vehicle 100. The tire 1 contacts the road surface. In the height direction, the distance between the position of the tire 1 and the position of the road surface is short.

  The actual image IMa of the tire 1 of the host vehicle 100 is acquired by the camera 201 of the following vehicle 200. Thus, the collision avoidance system of the following vehicle 200 can recognize the own vehicle 100 and estimate the distance between the own vehicle 100 and the following vehicle 200.

  As shown in FIG. 13, the tire 1 contacts the road surface in the height direction. When the tire 1 of the host vehicle 100 is extracted as a feature point, for example, even if the image IMb of the tire 1 projected onto the road surface wetted by rain is acquired by the camera 201, the image IMb of the tire 1 projected onto the road surface The error of the estimation result of the distance between the own vehicle 100 and the following vehicle 200 based on the above is suppressed.

  That is, when a portion having a large distance to the road surface in the height direction is extracted as a feature point, the optical path length of the image IMa from the characteristic point (the tail lamp 18 in this example) to the camera 201 and the optical path length of the image IMb Because the difference between the two points increases and the depression angle from the camera 201 changes, the position of the feature point in the entire image changes. As a result, the reliability of the estimation result of the distance between the own vehicle 100 and the following vehicle 200 may decrease regardless of the image recognition method.

  Furthermore, in the present embodiment, the tire 1 has a colored area 7 for image recognition. The colored area 7 is colored in a color that can perform image recognition at a high recognition rate, and is provided continuously in the circumferential direction. Therefore, even when the host vehicle 100 on which the tire 1 is mounted travels, the colored area 7 of the rotating tire 1 is recognized by the camera 201 of the following vehicle 200 at a high recognition rate.

  As described above, according to the present embodiment, since the third belt region 33 for image recognition is provided in the tire 1, the recognition rate of the tire 1 mounted on the own vehicle 100 by the camera 201 of the following vehicle 200 The decrease in As a result, the distance between the host vehicle 100 and the following vehicle 200 can be accurately estimated. Therefore, the collision of the following vehicle 200 with the host vehicle 100 is suppressed.

  Further, in the present embodiment, the colored area 7 of the third belt area 33 is provided in the circumferential direction. Therefore, even if the tire 1 mounted on the host vehicle 100 travels (rolls), the camera 201 of the following vehicle 200 can recognize the colored area 7 at a high recognition rate.

  In addition, the tire 1 contacts the road surface. In other words, the distance between the road surface and the tire 1 is short. Since the tire 1 is disposed at a position close to the road surface, for example, even if the image IMb of the tire 1 projected on the road surface wetted by rain is acquired by the camera 201, the self is based on the image of the tire 1 projected on the road surface. The error in the estimation result of the distance between the vehicle 100 and the following vehicle 200 is suppressed. Thereby, the decrease in the recognition rate of the tire 1 mounted on the host vehicle 100 is suppressed, and the collision of the following vehicle 200 with the host vehicle 100 is suppressed.

  Further, in the present embodiment, the reflectance of the colored area 7 to visible light is higher than the reflectance of the ground color area 13 to visible light. Thereby, the camera 201 can recognize the colored area 7 at a high recognition rate. For example, even during rainfall at night, the camera 201 can recognize the colored area 7 at a high recognition rate.

  Further, in the present embodiment, the colored region 7 of the third belt region 33 is provided on the surface of the shoulder portion 12. As a result, the contact between the colored area 7 of the third belt area 33 and the road surface is suppressed, and the colored area 7 can be made to last longer. Further, when the tire 1 is mounted on the vehicle 100, not only the camera 201 of the following vehicle 200 immediately behind (just behind), but also the camera 201 of the following vehicle 200 behind right and right (left) (left) The camera 201 of the following vehicle 200 of “behind” can also recognize the tire 1 of the own vehicle 100 at a high recognition rate.

  In each of the above-described embodiments, the colored region 7 is formed by applying the paint to the rubber that is the base. A part of the rubber may be colored. That is, the colored region 7 may be formed by the colored rubber layer. The colored rubber layer contains a coloring rubber containing a coloring agent. The tire 1 includes a colored rubber containing a colorant, and the colored region 7 includes the surface of the colored rubber, whereby the tire 1 having the colored region 7 can be easily manufactured.

Fourth Embodiment
A fourth embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  Drawing 14 is a figure showing an example of tire 1 concerning this embodiment. FIG. 14 shows a developed view of the tread portion 10 of the tire 1. As shown in FIG. 14, in the present embodiment, the surface of the tire 1 has a first belt region 31 for velocity measurement having a plurality of colored regions 7 intermittently provided in the circumferential direction of the central axis AX, and a center For image recognition having a second belt region 32 for identifying unique information having a plurality of colored regions 7 intermittently provided in the circumferential direction of the axis AX, and a colored region 7 provided in the circumferential direction of the central axis AX And a third belt region 33.

  In the example shown in FIG. 14, the first belt region 31 is disposed inside the vehicle in a state where the tire 1 is mounted on the vehicle. The third belt region 33 is disposed outside the vehicle. The second belt area 32 is disposed between the first belt area 31 and the third belt area 33 in the width direction.

  The first belt region 31 is provided on one shoulder portion 12 (shoulder region AR). The second belt region 32 is provided at the center portion 11. The third belt region 33 is provided on the other shoulder portion 12 (shoulder region AR).

  In the present embodiment, the surface of the tire 1 in which the first belt region 31 is disposed in the shoulder portion 12 is a flat surface. The groove 20 (lag groove 22) is not provided on the surface of the tire 1 on which the first belt region 31 is disposed.

  In the present embodiment, the surface of the tire 1 in which the third belt region 33 is disposed in the shoulder portion 12 is a flat surface. Grooves 20 (lag grooves 22) are not provided on the surface of the tire 1 on which the third belt region 33 is disposed.

  In the present embodiment, in the center portion 11, the surface of the tire 1 on which the second belt region 32 is disposed is a flat surface. Grooves 20 (lag grooves 22) are not provided on the surface of the tire 1 on which the second belt region 32 is disposed.

  Since the surface of the tire 1 on which the colored area 7 is provided is a flat surface, the colored area 7 is formed smoothly.

  The unique information of the tire 1 held by the second belt region 32 may include circumferential length data of the tire 1. The succeeding vehicle acquires circumferential length data of the tire 1 from the second belt area 32 and acquires rotational speed data of the tire 1 from the first belt area 31, based on the circumferential length data and the rotational speed data. The traveling speed of the leading own vehicle can be calculated more accurately.

  The unique information of the tire 1 held by the second belt region 32 may include width data indicating the width dimension of the tire 1. The succeeding vehicle acquires the width data of the tire 1 from the second belt area 32 and, based on the width data, calibrates the size of the tire 1 acquired from the image to obtain the dimensions of the correct tire 1 from the image data. Data can be obtained.

  The unique information of the tire 1 held by the second belt region 32 may include full width data indicating the dimension of the full width of the vehicle (self-vehicle) on which the tire 1 is mounted. The succeeding vehicle acquires the full width data of the vehicle from the second belt area 32, and corrects the size of the vehicle and the size of the tire 1 acquired from the image based on the full width data to correct the image data from the image data The dimensional data of the vehicle and the dimensional data of the correct tire 1 can be acquired.

Fifth Embodiment
A fifth embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  FIG. 15 is a view schematically showing an example of the second belt region 32 according to the present embodiment. As shown in FIG. 15, the second belt region 32 includes a first second belt region 32A for identifying unique information having a plurality of colored regions 7 provided intermittently in the circumferential direction of the central axis AX, and a center A second belt area for identifying the second unique information having a plurality of colored areas 7 provided on the inner side of the second belt area 32A in the radial direction with respect to the axis AX and intermittently provided in the circumferential direction of the central axis AX. And 32B. The second belt region 32A is disposed outside the second belt region 32B in the radial direction. The second belt region 32 </ b> B is embedded in the tread rubber 6. The second belt area 32A includes the first unique information. The second belt area 32B includes second unique information different from the first unique information.

  At the initial stage of wear of the tread rubber 6, the colored area 7 of the second belt area 32A is disposed on the surface of the tire 1. An image of the second belt area 32A is acquired by the camera of the following vehicle. The camera of the following vehicle acquires an image of the second belt area 32A, and acquires the first unique information of the tire 1. At the initial stage of wear of the tread rubber 6, the second belt region 32 </ b> B is embedded in the tread rubber 6. Therefore, at the initial stage of wear of the tread rubber 6, the camera of the following vehicle acquires an image of the second belt region 32A and does not acquire an image of the second belt region 32B. At the initial stage of wear of the tread rubber 6, the camera of the following vehicle acquires the first unique information of the tire 1 and does not acquire the second unique information of the tire 1.

  The running of the tire 1 causes the tread rubber 6 to wear. At the middle stage of wear or at the end of wear of the tread rubber 6, the second belt area 32A disappears, and the colored area 7 of the second belt area 32B is disposed on the surface of the tire 1. An image of the second belt area 32B is acquired by the camera of the following vehicle. The camera of the following vehicle acquires an image of the second belt region 32B, and acquires second unique information of the tire 1. The second belt region 32A disappears at the middle stage of wear or at the end of wear of the tread rubber 6. Therefore, in the middle stage or the last stage of wear of the tread rubber 6, the camera of the following vehicle acquires an image of the second belt area 32B and does not acquire an image of the second belt area 32A. In the middle stage or the last stage of wear of the tread rubber 6, the camera of the following vehicle acquires the second unique information of the tire 1 and does not acquire the first unique information of the tire 1.

  The unique information of the tire 1 held by the second belt region 32B may include wear data indicating the amount of wear of the tread rubber 6.

  As described above, according to the present embodiment, it is possible to change the unique information of the tire 1 acquired by the camera of the following vehicle based on the wear amount of the tread rubber 6. As a result, the following vehicle 200 can grasp the worn state of the tread portion 10 of the tire 1.

Sixth Embodiment
A sixth embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  FIG. 16 is a view showing an example of the first belt area 31 according to the present embodiment. In the present embodiment, the dimension La of the colored region 7 of the first belt region 31 in the circumferential direction and the dimension Lb of the blank region 25 in the circumferential direction will be described. As described above, the blank area 25 includes the ground color area 13 between the adjacent colored areas 7.

  The dimension La of the colored area 7 and the dimension Lb of the blank area 25 are preferably 5 [°] or more and 22.5 [°] or less in terms of the angle α in the circumferential direction of the tire 1. The dimension La and the dimension Lb can be obtained based on the outer diameter OD of the tire 1 (the distance between the central axis AX and the surface of the tread portion 10) and the angle α. For example, the dimension La or the dimension Lb can be determined by performing an operation of π × OD × (α / 360).

  22.5 [°] corresponds to one division length when one circumferential length (circumferential) of the tire 1 is divided into eight. The dimension of the tire 1 with respect to the circumferential direction, which can be seen from the following vehicle at one time, is approximately 45 degrees in terms of the angle α in the circumferential direction of the tire 1. That is, the circumferential dimension of the tire 1 seen at one time from the following vehicle is π × OD × (45/360). Therefore, if the dimension La and the dimension Lb are larger than the dimension (π × OD × (22.5 / 360)) corresponding to 22.5 °, the cameras of the following vehicles are intermittently provided There is a possibility that the colored area 7 (or the blank area 25) of the white background can not be distinguished. When the dimension La and the dimension Lb are smaller than the dimension (π × OD × (5/360)) corresponding to 5 °, in the image acquired by the camera of the following vehicle, the colored region 7 and the blank region 25 are The area is too small, and the pattern formed by the colored area 7 and the blank area 25 may not be recognizable.

  When the dimension La of the colored area 7 and the dimension Lb of the blank area 25 are 5 [°] or more and 22.5 [°] or less in terms of the angle α in the circumferential direction of the tire 1, the camera of the following vehicle The pattern formed by the colored area 7 and the blank area 25 can be well recognized.

Seventh Embodiment
A seventh embodiment will be described. In the following description, the same code | symbol is attached | subjected to a component the same as that of the above-mentioned embodiment, or equivalent, and the description is simplified or abbreviate | omitted.

  FIG. 17 is a view showing an example of a vehicle 100 according to the present embodiment. As shown in FIG. 17, in the present embodiment, the vehicle 100 includes an illumination device 300 that illuminates the tire 1 mounted on the rearmost wheel. For example, at night, the tire 1 is illuminated by the illumination device 300.

  The lighting device 300 is supported by the vehicle body 14. The lighting device 300 is disposed rearward of the tire 1 mounted on the rearmost wheel. The lighting device 300 is supported by the vehicle body 14 of the own vehicle 100 between the tire 1 of the own vehicle 100 and the camera 201 of the following vehicle 200. The lighting device 300 illuminates the tire 1 from the rear of the tire 1.

  As described above, by lighting the tire 1 by the lighting device 300, the camera 201 of the following vehicle 200 can recognize the tire 1 of the own vehicle 100 at a high recognition rate even at night, for example.

  In each of the above-described embodiments, the tire 1 is mounted on the host vehicle 100, and the following vehicle 200 following the host vehicle 100 includes the collision avoidance system including the camera 201. Thereby, the own vehicle 100 can be suppressed from being hit by the following vehicle 200. As shown in FIG. 18, the tire 1 may be mounted on a preceding vehicle 100F preceding the own vehicle 100, and the following vehicle 100F may have a collision avoidance system including the camera 101. As a result, the host vehicle 100 can recognize the leading vehicle 100F at a high recognition rate, and can suppress a rear collision on the leading vehicle 100F.

1 Tire (Pneumatic tire)
2 carcass portion 3 belt layer 3A first belt ply 3B second belt ply 4 belt cover 5 bead portion 6 tread rubber 7 colored area 8 side wall rubber 9 side wall portion 10 tread portion 11 center portion 12 shoulder portion 13 ground color region 14 Body 18 Tail lamp 20 Groove 21 Main groove 22 Lug groove 25 Blank area 31 1st belt area 32 2nd belt area 32A 2nd belt area 32B 2nd belt area 33 3rd belt area 60 Grounding end 70 End part 100 Vehicle vehicle)
100F vehicle (preceding vehicle)
101 Camera 200 Vehicle (following vehicle)
201 Camera 300 Lighting device La Dimension Lb Dimension OD Tire outer diameter RD Tire rim diameter SW Tire total width W Tread contact width TDW Tread development width

Claims (12)

A pneumatic tire having a surface and rotatable about a central axis,
The surface is
Ground color area including the surface of rubber,
See containing and a first belt region for speed measurement having a plurality of colored regions provided intermittently in the circumferential direction of said central axis,
The vehicle is mounted on at least the rearmost one of the plurality of wheels of the vehicle and is illuminated by a lighting device provided in the vehicle.
Pneumatic tire.   The pneumatic tire according to claim 1, wherein the reflectance of the colored area to visible light is higher than the reflectance of the ground color area. Equipped with a shoulder
The pneumatic tire according to claim 1, wherein the first belt region is provided on a surface of the shoulder portion.   The pneumatic tire according to any one of claims 1 to 3, wherein the dimensions of the plurality of colored regions are different with respect to the circumferential direction.   The surface according to any one of claims 1 to 4, further comprising a second belt region for identifying unique information having a plurality of colored regions intermittently provided in a circumferential direction of the central axis. Pneumatic tire.   The pneumatic tire according to any one of claims 1 to 5, wherein the surface further includes a third belt region for image recognition having a colored region provided in a circumferential direction of the central axis.   The pneumatic tire according to any one of claims 1 to 6, wherein the dimension of the colored area of the first belt area with respect to the direction parallel to the central axis is 5 mm or more.   The pneumatic tire according to any one of claims 1 to 7, wherein the colored area includes a surface of a paint applied to the rubber.   The pneumatic tire according to claim 8, wherein the paint contains a fluorescent paint.   The pneumatic tire according to claim 8, wherein the paint contains a retroreflective material. Contains colored rubber containing colorants,
The pneumatic tire according to any one of claims 1 to 7, wherein the colored area includes a surface of the colored rubber. With multiple wheels,
The pneumatic tire according to any one of claims 1 to 11, mounted on at least the rearmost wheel among the plurality of wheels.
A lighting device for lighting the pneumatic tire mounted on the last wheel;
Vehicles equipped with

Images