Tire information detection device

Abstract

Provided is a tire information detection device that is capable of detecting tire information at appropriate times and locations while increasing the lifespan of a power supply unit by reducing the measurement frequency of a detection unit (sensor) as much as possible. A tire information detection device for detecting tire information including at least one from among tire wear, tire deformation, a road surface condition, a tire ground contact state, the presence or absence of a tire failure, a tire travel history, a tire load state, and the coefficient of friction, the tire information detection device comprising at least one detection unit 11 disposed on the inner surface of the tire, a power supply unit 12 for supplying power to the detection unit 11, a position information detection unit 13 for detecting position information for the tire or a vehicle, an additional information acquisition unit 14 for acquiring additional information associated with the position information, a determination unit 15 for determining whether a current position specified on the basis of the position information is included in a region matching a determination condition extracted from the additional information, and a control unit 16 for controlling measurement by the detection unit 11 on the basis of the determination result of the determination unit 15.

Description

[Technical Field]

[0001] The present invention relates to a tire information detection device, and more specifically to a tire information detection device that is capable of detecting tire information at the appropriate time and place while reducing the measurement frequency of a detection unit (sensor) installed in a tire as much as possible to extend the life of the power supply unit. [Background technology]

[0002] In pneumatic tires, for example, an acceleration sensor is installed inside the tire to measure acceleration, and tire information (the state of wear of the tread portion) is evaluated based on the measured value (see, for example, Patent Document 1). Such sensors generally use a battery as a power source and have a function to transmit measurement data measured by the sensor to an external device. The more measurements and transmissions the sensor performs, the more battery power is consumed, resulting in a problem of shortened battery life. Battery life can be improved by reducing the frequency of sensor measurements to the bare minimum, but in that case, it becomes necessary to equip the sensor with a trigger function to prompt the sensor to perform measurements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-18667 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a tire information detection device that can detect tire information at the appropriate time and place while reducing the measurement frequency of the detection unit (sensor) installed in the tire as much as possible to extend the life of the power supply unit. [Means for solving the problem]

[0005] In order to achieve the above object, the tire information detection device of the present invention detects tire information including at least one of tire wear, tire deformation, road surface condition, tire contact condition, presence or absence of tire failure, tire running history, tire load condition, and friction coefficient, and includes at least one detection unit arranged on the inner surface of the tire, a power supply unit that supplies power to the detection unit, a position information detection unit that detects position information of the tire or vehicle, an additional information acquisition unit that acquires additional information linked to the position information, a determination unit that determines whether a current position specified based on the position information is included in an area that matches a determination condition extracted from the additional information, and a control unit that controls measurement by the detection unit based on the determination result of the determination unit. and an accident risk calculation unit that calculates an index value of the accident risk for each area based on the number of accidents included in the additional information, wherein the determination unit uses the index value of the accident risk for each area as a determination condition, and the control unit controls the measurement by the detection unit based on the index value of the accident risk in the area that includes the current location. It is characterized by the following. Furthermore, a tire information detection device of the present invention detects tire information including at least one of tire wear, tire deformation, road surface condition, tire contact condition, presence or absence of tire failure, tire running history, tire load condition, and friction coefficient, and is equipped with at least one detection unit arranged on the inner surface of the tire, a power supply unit that supplies power to the detection unit, a position information detection unit that detects position information of the tire or the vehicle, an additional information acquisition unit that acquires additional information linked to the position information, a determination unit that determines whether a current position specified based on the position information is included in an area that matches a determination condition extracted from the additional information, and a control unit that controls measurement by the detection unit based on a determination result of the determination unit, and has an image comparison calculation unit that compares a pre-recorded image of the surroundings of the vehicle included in the additional information with an image taken while the vehicle is running to calculate a match rate of the images, and the determination unit uses the match rate of the images as a determination condition, and the control unit controls measurement by the detection unit based on the match rate of the images in the area including the current position. a control unit that controls measurement by the detection unit based on a determination result of the determination unit; and a risk avoidance behavior recording unit that records information about a risk avoidance behavior at the current location identified based on the location information, and a risk index calculation unit that calculates a risk index value for each area based on the information about the risk avoidance behavior. The tire information detection device detects tire information including at least one of tire wear, tire deformation, road surface conditions, tire contact condition, presence or absence of a tire fault, tire running history, tire load condition, and friction coefficient, and is characterized in that the tire information detection device includes at least one detection unit arranged on the inner surface of the tire, a power supply unit that supplies power to the detection unit, a position information detection unit that detects position information of the tire or the vehicle, an additional information acquisition unit that acquires additional information linked to the position information, a determination unit that determines whether a current location identified based on the position information is included in an area that matches a determination condition extracted from the additional information, and a control unit that controls measurement by the detection unit based on a determination result of the determination unit. [Effects of the Invention]

[0006] The present invention includes at least one detector disposed on the inner surface of the tire, a power supply unit that supplies power to the detector, a location information detector that detects tire or vehicle location information, an additional information acquisition unit that acquires additional information linked to the location information, a determination unit that determines whether the current location determined based on the location information is within an area that matches the determination criteria extracted from the additional information, and a control unit that controls measurement by the detector based on the determination result of the determination unit. Therefore, the tire information detection device is configured to use the tire or vehicle location information and perform measurement when the current location determined based on the location information is within an area that matches the determination criteria extracted from the additional information. In other words, the tire information detection device of the present invention includes a trigger function that triggers measurement by the detector, allowing measurements to be performed at appropriate times and locations rather than constantly, thereby reducing the measurement frequency of the detector as much as possible and reducing power consumption. This allows tire information to be detected at appropriate times and locations while extending the life of the power supply unit.

[0007] In the tire information detection device of the present invention, it is preferable that the determination unit has at least two determination conditions and uses the at least two determination conditions depending on the tire information to be detected, thereby achieving both a long life for the power supply unit and timely and appropriate detection of tire information.

[0008] It is preferable to have an accident risk calculation unit that calculates an index value for the accident risk for each region based on the number of accidents included in the additional information, the determination unit uses the index value for the accident risk for each region as a determination condition, and the control unit controls the measurement by the detection unit based on the index value for the accident risk in the region that the current location is in. This leads to a reduction in the risk of accidents while extending the life of the power supply unit, thereby improving safety.

[0009] It is preferable that the tire information includes tire wear, the determination unit uses information related to tire wear included in the additional information as a determination condition, and the detection unit repeats measurement until the tire rotation count reaches 10 or more rotations. This makes it possible to improve the accuracy of determining the degree of tire wear while extending the life of the power supply unit, particularly when detecting tire wear as tire information.

[0010] It is preferable that the device has a measurement frequency calculation unit that calculates an index value for the measurement frequency of the detection unit based on the environmental information included in the additional information, the determination unit uses the index value of the measurement frequency of the detection unit as a determination condition, and the control unit controls the measurement of the detection unit based on the index value of the measurement frequency of the detection unit in the area that the current location is in. This leads to a longer life for the power supply unit while reducing the risk of accidents, thereby improving safety.

[0011] It is preferable that the system has an image comparison calculation unit that compares pre-recorded images of the vehicle's surroundings included in the additional information with images taken while the vehicle is in motion to calculate a match rate for the images, the determination unit uses the match rate of the images as a condition for determination, and the control unit controls the measurement by the detection unit based on the match rate for the images in the area that includes the current position. This leads to a reduction in the risk of accidents, thereby improving safety.

[0012] It is preferable that the device has a measurement history recording unit that records the measurement history of the detection unit at the current location specified based on the location information, the determination unit uses the presence or absence of the measurement history of the detection unit as a determination condition, and the control unit controls the measurement of the detection unit based on the presence or absence of the measurement history of the detection unit in the area that includes the current location. This leads to a reduction in the risk of accidents occurring, thereby improving safety.

[0013] It is preferable that the device has a danger avoidance behavior recording unit that records information on danger avoidance behavior at a current location specified based on location information, and a danger index calculation unit that calculates a danger index value for each area based on the information on the danger avoidance behavior, wherein the determination unit uses the danger index value for each area as a determination condition, and the control unit controls the measurement by the detection unit based on the danger index value for the area that the current location is in. This leads to a reduction in the risk of accidents occurring, thereby improving safety. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram showing an example of a tire information detection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart showing an example of the procedure of a detection method using a tire information detection device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing a modified example of the procedure of the detection method using the tire information detection device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a meridian cross-sectional view showing a pneumatic tire whose tire information is detected by a tire information detection device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings, in which: Figure 1 shows a tire information detection device according to an embodiment of the present invention;

[0016] When detecting tire information of a tire T (see, for example, Figure 4), the tire information detection device 10 detects the tire information of the tire T while controlling the measurement of the detection unit 11, which will be described later, based on the position information of the tire T or the vehicle on which the tire T is mounted.

[0017] The tire information is a group consisting of tire wear, tire deformation, road surface condition, tire contact condition, tire malfunction, tire running history, tire load condition, and friction coefficient. At least one item can be selected from this group and used as tire information. The tire information is not limited to the above group, and additional information may be added as appropriate.

[0018] 1, the tire information detection device 10 includes at least one detection unit 11 that detects the condition of a tire, a power supply unit 12 that supplies power to the detection unit 11, a location information detection unit 13 that detects location information of the tire or the vehicle, an additional information acquisition unit 14 that acquires additional information linked to the location information, a determination unit 15 that determines whether the current location of the tire or the vehicle is included in an area that meets specific determination conditions, and a control unit 16 that controls measurement by the detection unit 11 based on the determination result of the determination unit 15. Note that the processes performed by the location information detection unit 13, the additional information acquisition unit 14, the determination unit 15, and the control unit 16 may be executed on the vehicle side or on a cloud side that is communicably connected to the vehicle.

[0019] The tire information detection device 10 may further include a calculation unit 17 that performs various calculation processes and a recording unit 18 that records various data. In addition, the tire information detection device 10 may be appropriately equipped with devices such as an input device, an output device, and a display.

[0020] The detection unit 11 is not particularly limited, but may include, as appropriate, a voltage detection unit (potential sensor) that detects a potential difference in an element that generates a voltage based on deformation of the tread portion during tire rotation, a speed detection unit (speed sensor) that detects the vehicle speed or the tire rotation speed, an air pressure detection unit (pressure sensor) that detects the internal pressure of the tire, and a temperature detection unit (temperature sensor) that detects the internal temperature of the tire. The detection unit 11 also includes a transmitter that transmits data to the outside. The data detected by the detection unit 11 is recorded in the recording unit 18.

[0021] The power supply unit 12 can be, for example, a battery, but is not limited to this, and may be a device that supplies power contactlessly via radio waves or the like, as long as it can supply power to the detection unit 11. The power supply unit 12 can supply power not only to the detection unit 11, but also to the position information detection unit 13, additional information acquisition unit 14, determination unit 15, control unit 16, calculation unit 17, and recording unit 18.

[0022] The position information detection unit 13 continuously detects the position information of the tire or vehicle and can identify the current position of the tire or vehicle based on the position information. This position information includes the latitude, longitude, and altitude of the point where the tire or vehicle is located. If, for example, a small GPS (Global Positioning System) is used as the position information detection unit 13, the position information detection unit 13 can be mounted on the tire information detection device 10. Alternatively, the position information detection unit 13 may acquire position information from a GPS mounted on the vehicle. In this case, the position information detection unit 13 includes means for communicating with the GPS of the vehicle (transmitter and receiver). The GPS detects the position information (latitude, longitude, and altitude) of the tire or vehicle by receiving radio waves from an artificial satellite.

[0023] The additional information acquisition unit 14 acquires additional information linked to the tire or vehicle position information. This additional information may include, as appropriate, information about surrounding buildings, road curvature, road gradient, road signs, intersections, inbound and outbound lanes, medians, accident-prone areas, traffic congestion areas, flooded areas, snow-covered areas, areas prone to leaf accumulation, weather information, sunshine hours, images from a camera or drive recorder mounted on the vehicle, and satellite images of the vehicle's surroundings, corresponding to the tire or vehicle position information. When an internal storage device such as RAM is used as the additional information acquisition unit 14, the additional information acquisition unit 14 can be mounted on the tire information detection device 10. Alternatively, the additional information acquisition unit 14 may utilize information recorded in a navigation system mounted on the vehicle. In this case, the additional information acquisition unit 14 includes a means for communicating with the vehicle's navigation system (transmitter and receiver). In particular, the additional information acquisition unit 14 is preferably configured to be able to communicate with an external database. In this case, the additional information can be updated as needed, allowing the latest additional information to be acquired.

[0024] The additional information acquisition unit 14 also extracts specific information from the additional information linked to the location information according to the tire information of the detection target. This extracted additional information is recorded in the additional information acquisition unit 14 itself and used as a judgment condition for the judgment unit 15. For example, if the detection target is road surface conditions, the additional information appropriately extracts road signs, intersections, accident-prone areas, traffic jam-prone areas, flooded areas, snow-covered areas, areas prone to leaf accumulation, weather information, sunshine hours, images from a camera or drive recorder mounted on the vehicle, and satellite images of the area around the vehicle. If the detection target is tire wear, the additional information appropriately extracts nearby buildings, accident-prone areas, areas where the user is likely to drive at a consistent speed on a specific road, and the like. If the detection target is tire deformation or tire load state, the additional information appropriately extracts nearby buildings, accident-prone areas, and the like.

[0025] The determination unit 15 determines whether the current location specified based on the tire or vehicle position information is included in an area that matches the determination conditions. In doing so, the determination unit 15 makes the determination using the determination conditions extracted by the additional information acquisition unit 14 according to the tire information of the detection target. The determination unit 15 also reads the determination conditions appropriately from the additional information acquisition unit 14 or the recording unit 18 and performs the determination. Note that the "area that matches the determination conditions" refers to an area (range) that includes both the case where the current location is exactly at a point that matches the determination conditions and the case where the current location is close to a point that matches the determination conditions.

[0026] It is preferable that the determination unit 15 has at least two determination conditions and uses the at least two determination conditions depending on the tire information to be detected, because appropriate determination conditions may differ depending on the tire information to be detected.

[0027] The control unit 16 controls the measurement of the detection unit 11 based on the determination result of the determination unit 15. Specifically, if the current position of the tire or vehicle is included in an area that meets the determination conditions, the control unit 16 controls the detection unit 11 to start measurement, or to continue measurement if measurement is already in progress. On the other hand, if the current position of the tire or vehicle is not included in an area that meets the determination conditions, the control unit 16 controls the detection unit 11 not to start measurement, or to end measurement if measurement is already in progress.

[0028] The calculation unit 17 can be configured with, for example, a memory or a CPU. The calculation unit 17 stores the calculated index value in the recording unit 18 and can also read out the stored index value to perform calculations. The calculation unit 17 can also correct the judgment conditions extracted from additional information linked to the position information. For example, if the detection target is tire deformation or tire load state, the calculation unit 17 makes corrections based on road gradient and vehicle information (information such as axle load, number of occupants, brake pressure, steering angle, etc.). The calculation unit 17 can also include an accident occurrence risk calculation unit 17a, a measurement frequency calculation unit 17b, an image comparison calculation unit 17c, and a danger index calculation unit 17d.

[0029] The accident risk calculation unit 17a calculates an index value of the accident risk for each region based on information on accident-prone regions (e.g., information on the number of accidents in each region) included in the additional information acquired by the additional information acquisition unit 14. Specifically, it calculates the ratio of the number of accidents in a specific region to the total number of accidents in an arbitrary range (e.g., a city, a prefecture, etc.), and quantifies the accident risk for each region in stages. In this case, the accident risk for each region is preferably rated on a 5-stage scale, more preferably on a 10-stage scale, with a higher index value indicating a higher accident risk.

[0030] When the tire information detection device 10 includes the accident risk calculation unit 17a, the determination unit 15 uses the accident risk index value for each region calculated by the accident risk calculation unit 17a as a determination condition, and the control unit 16 controls the measurement by the detection unit 11 based on the accident risk index value for the region including the current location. Specifically, the control unit 16 controls the detection unit 11 to measure more frequently in regions with a higher accident risk index value. For example, the detection unit 11 may perform measurement once a week in regions with a level 1 accident risk and perform measurement every time the vehicle passes through a region with a level 10 accident risk. However, to prevent the life of the power supply unit 12 from being shortened, it is preferable to set an upper limit on the number of measurements (maximum of three times per day). Furthermore, even when passing through a region that is not a high-accident region, it is preferable to control the detection unit 11 to perform measurement if similarities with other high-accident regions are recognized. In this case, for example, four items, visibility from the height and arrangement of surrounding buildings, presence or absence of traffic lights, presence or absence of road signs, and traffic volume, are normalized, and the total value of each item is calculated with 25 points for each item, and if the similarity with other accident-prone areas is 65 points or more, measurement is performed by the detection unit 11. Note that when evaluating the similarity with other accident-prone areas, items other than the above four exemplified items may be added as appropriate.

[0031] The measurement frequency calculation unit 17b calculates an index value for the measurement frequency of the detection unit 11 based on the environmental information included in the additional information acquired by the additional information acquisition unit 14. Examples of this environmental information include weather information (e.g., rainfall information and snow accumulation information), areas where fallen leaves tend to accumulate, and sunshine hours. The measurement frequency calculation unit 17b calculates the measurement frequency of the detection unit 11 based on this environmental information and gradually quantifies it. For example, the measurement frequency is increased when it rains or snows based on the rainfall information or snow accumulation information, and the measurement frequency is increased in autumn in areas where fallen leaves tend to accumulate. Note that the larger the index value for the measurement frequency of the detection unit 11, the more frequently the detection unit 11 measures.

[0032] If the tire information detection device 10 includes a measurement frequency calculation unit 17b, the determination unit 15 uses the index value of the measurement frequency of the detection unit 11 calculated by the measurement frequency calculation unit 17b as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the index value of the measurement frequency of the detection unit 11 in the area including the current location. Specifically, the control unit 16 controls the detection unit 11 so that the measurement frequency increases in areas with a larger index value of the measurement frequency of the detection unit 11. For example, if the index value of the measurement frequency of the detection unit 11 is set to three levels, the detection unit 11 will perform measurement once a week in areas with a measurement frequency index value of level 1 and will perform measurement every time the detection unit 11 passes through an area with a measurement frequency index value of level 3. In addition, taking into account the season and the hours of sunlight, the control can be performed so that the detection unit 11 performs measurement in the morning and evening but not during the day.

[0033] The image comparison calculation unit 17c compares a pre-recorded image of the vehicle's surroundings included in the additional information with an image taken while the vehicle is traveling to calculate a match rate of the images. Specifically, the image comparison calculation unit 17c calculates, through image processing, a match rate between a pre-recorded image of the vehicle's surroundings (e.g., an image of the vehicle's surroundings taken by a satellite photograph) and an image taken while the vehicle is traveling (e.g., an image taken by a camera or a drive recorder mounted on the vehicle).

[0034] When the tire information detection device 10 has the image comparison calculation unit 17c, the determination unit 15 uses the image matching rate as a determination condition, and the control unit 16 controls the measurement by the detection unit 11 based on the image matching rate in the area including the current location. Specifically, the control unit 16 controls the detection unit 11 to perform measurement when the image matching rate is low (for example, when the matching rate is 65% or less).

[0035] Various measurement values ​​measured by the detection unit 11 are recorded in the recording unit 18. Here, the recording unit 18 can be configured as an external recording device such as a hard disk, an internal recording device such as a RAM, or a combination of these. The recording unit 18 can also include a measurement history recording unit 18a and a danger avoidance behavior recording unit 18b.

[0036] The measurement history recording unit 18a records the measurement history of the detection unit 11 at the current position identified based on the position information. That is, the measurement history recording unit 18a associates the position information with the measurement history of the detection unit 11 and records them integrally.

[0037] When the tire information detection device 10 has the measurement history recording unit 18a, the determination unit 15 uses the presence or absence of the measurement history of the detection unit 11 as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the presence or absence of the measurement history of the detection unit 11 in the area including the current location. Specifically, when the measurement history of the detection unit 11 is not recorded in the measurement history recording unit 18a, the control unit 16 controls the detection unit 11 to start measurement.

[0038] The danger avoidance behavior recording unit 18b records information about danger avoidance behavior at the current location identified based on the location information. That is, the danger avoidance behavior recording unit 18b links the location information and the danger avoidance behavior and records them together. Examples of this danger avoidance behavior include abrupt braking, abrupt steering, and abrupt changes in vehicle speed. The risk index calculation unit 17d also calculates a risk index value for each region based on the information about the danger avoidance behavior recorded in the danger avoidance behavior recording unit 18b. Specifically, the risk index calculation unit 17d calculates the ratio of the number of danger avoidance behaviors in a specific region to the total number of danger avoidance behaviors in an arbitrary range (e.g., a city, a prefecture, etc.) and quantifies the risk for each region in stages. In this case, the risk for each region is preferably rated on a 5-point scale, more preferably on a 10-point scale, with a higher index value indicating a higher number of danger avoidance behaviors and a higher risk of an accident occurring.

[0039] When the tire information detection device 10 includes the danger avoidance behavior recording unit 18b and the danger index calculation unit 17d, the determination unit 15 uses the danger index value for each region as a determination condition, and the control unit 16 controls the detection unit 11 to measure based on the danger index value for the region including the current location. Specifically, the control unit 16 controls the detection unit 11 to measure more frequently in regions with higher danger index values. For example, the detection unit 11 may perform measurements once a week in regions with a danger index value of level 1 and perform measurements every time the vehicle passes through a region with a risk index value of level 10. However, to prevent the life of the power supply unit 12 from being shortened, it is preferable to set an upper limit on the number of measurements (maximum of three times per day). In this way, the control unit 16 controls the detection unit 11 to start measurement when information on danger avoidance behavior is recorded in the danger avoidance behavior recording unit 18b.

[0040] Fig. 2 shows the procedure of a detection method using a tire information detection device according to an embodiment of the present invention. In Fig. 2, the detection unit 11 mounted on the tire information detection device 10 starts from a state in which it is not performing measurements.

[0041] In detecting the tire information of the tire T, in step S1, the position information detection unit 13 of the tire information detection device 10 detects the position information (latitude, longitude, altitude) of the tire or the vehicle. Then, the position information detection unit 13 identifies the current position of the tire or the vehicle based on the detected position information.

[0042] Next, the process proceeds to step S2, where the additional information acquisition unit 14 of the tire information detection device 10 acquires additional information linked to the tire or vehicle position information. Then, the additional information acquisition unit 14 extracts specific information from the additional information linked to the position information according to the tire information to be detected. This extracted additional information is used as a judgment condition for the judgment unit 15.

[0043] Next, the process proceeds to step S3, where the determination unit 15 of the tire information detection device 10 determines whether the current location of the tire or vehicle is included in an area that matches the determination conditions extracted from the additional information. For example, if the detection target is road surface conditions, the determination unit 15 determines whether the current location is included in a specific area (such as an accident-prone area, a flooded area, or an area prone to leaf accumulation). If the detection target is tire wear, the determination unit 15 determines whether the current location is included in an area where a pre-recorded user is likely to drive on a fixed route. If the detection target is tire deformation or tire load condition, the determination unit 15 determines whether the current location is included in an area that matches the determination conditions corrected based on road gradient and vehicle information. If the current location is included in an area that matches the determination conditions, the process proceeds to step S4. If the current location is not included in an area that matches the determination conditions, the process returns to step S1.

[0044] Next, the process proceeds to step S4, where the control unit 16 of the tire information detection device 10 controls the detection unit 11 to start measurement. The detection unit 11 starts measurement in this way, and steps S1 to S3 are repeated while the vehicle is traveling. If the current position is no longer included in an area that matches the determination condition in step S3, the control unit 16 controls the detection unit 11 to end measurement. The current position changes from moment to moment as the vehicle travels, and the determination condition extracted from the additional information linked to the position information also changes accordingly, so the detection unit 11 also starts and ends measurement repeatedly as appropriate while the vehicle is traveling.

[0045] In addition, when the detection target is tire wear, the measurement frequency of the detection unit 11 becomes relatively low, when the detection target is the road surface condition, the measurement frequency of the detection unit 11 becomes relatively high, and when the detection target is tire deformation, ground contact condition or load condition, the measurement frequency of the detection unit 11 is changed appropriately according to the request.

[0046] The tire information detection device described above includes at least one detector 11 disposed on the inner surface of the tire, a power supply 12 that supplies power to the detector 11, a location information detector 13 that detects tire or vehicle location information, an additional information acquisition unit 14 that acquires additional information linked to the location information, a determination unit 15 that determines whether the current location determined based on the location information is within an area that matches the determination criteria extracted from the additional information, and a control unit 16 that controls measurement by the detector 11 based on the determination result of the determination unit 15. Therefore, the tire information detection device is configured to use tire or vehicle location information, and to perform measurement when the current location determined based on the location information is within an area that matches the determination criteria extracted from the additional information. That is, the tire information detection device of the present invention includes a trigger function that triggers measurement by the detector 11. This allows measurement to be performed at appropriate times and locations rather than constantly, thereby reducing the measurement frequency of the detector 11 as much as possible and reducing power consumption. This allows tire information to be detected at appropriate times and locations while extending the life of the power supply 12.

[0047] The tire information detection device preferably has an accident risk calculation unit 17a that calculates an index value for the accident risk based on the number of accidents for each region included in the additional information, the determination unit 15 uses the index value for the accident risk for each region as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the index value for the accident risk in the region that includes the current location. By using the index value calculated by the accident risk calculation unit 17a as a determination condition in this way, the risk of accidents can be reduced while the life of the power supply unit 12 is extended, thereby improving safety.

[0048] It is preferable to have a measurement frequency calculation unit 17b that calculates an index value for the measurement frequency of detection unit 11 based on the environmental information included in the additional information, the determination unit 15 using the index value for the measurement frequency of detection unit 11 as a determination condition, and the control unit 16 controlling the measurement of detection unit 11 based on the index value for the measurement frequency of detection unit 11 in the area that includes the current location. By using the index value for the measurement frequency of detection unit 11 calculated by measurement frequency calculation unit 17b as a determination condition in this way, the life of power supply unit 12 can be extended while reducing the risk of accidents, thereby improving safety.

[0049] Furthermore, it is preferable that the tire information detection device has an image comparison calculation unit 17c that compares pre-recorded images of the vehicle's surroundings included in the additional information with images taken while the vehicle is traveling to calculate a match rate of the images, the determination unit 15 uses the image match rate as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the image match rate in the area including the current location.Even if the current location is not included in an accident-prone area, if the image match rate does not satisfy a predetermined value, the detection unit 11 is controlled to perform measurement, which leads to a reduction in the risk of accidents occurring and therefore improves safety.

[0050] It is preferable that the vehicle has a measurement history recording unit 18a that records the measurement history of the detection unit 11 at the current position specified based on the position information, the determination unit 15 uses the presence or absence of the measurement history of the detection unit 11 as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the presence or absence of the measurement history of the detection unit 11 in the area including the current position. For example, when a vehicle is traveling through an intersection that it is entering for the first time, even if the intersection is not in an accident-prone area, controlling the detection unit 11 to perform measurements can reduce the risk of accidents, thereby improving safety.

[0051] It is preferable that the system has a danger avoidance behavior recording unit 18b that records information about danger avoidance behavior at the current location specified based on the location information, and a danger index calculation unit 17d that calculates a danger index value for each area based on the information about the danger avoidance behavior, the determination unit 15 uses the danger index value for each area as a determination condition, and the control unit 16 controls the measurement of the detection unit 11 based on the danger index value for the area that includes the current location. Even if the current location is not included in an accident-prone area, if information about danger avoidance behavior is recorded in the danger avoidance behavior recording unit 18b, controlling the detection unit 11 to perform measurement will lead to a reduction in the risk of accidents, thereby improving safety.

[0052] Furthermore, in the tire information detection device, the tire information preferably includes tire wear, and the determination unit 15 preferably uses information related to tire wear included in the additional information as a determination condition, and the detection unit 11 preferably repeats measurement until the tire rotation count reaches 10 or more rotations. While it is possible to determine the degree of tire wear even with a single tire rotation measurement, to improve the determination accuracy, the tire rotation count is preferably 30 or more rotations, more preferably 50 or more rotations, and most preferably 100 or more rotations. In this case, the detection unit 11 may perform measurement continuously or intermittently over multiple days. Furthermore, when the determination unit 15 makes a determination based on the determination condition, a machine learning model may be used, which also improves the determination accuracy. Examples of machine learning models that can be used include decision trees, random forests, logistic regression, support vector machines (SVMs), naive Bayes classifiers, k-nearest neighbors, Adaboost, and neural networks. In this way, by performing measurements using the detection unit 11 until a predetermined number of tire rotations is reached, when detecting tire wear, the accuracy of determining the degree of tire wear can be improved while extending the life of the power supply unit 12.

[0053] It is desirable that the above measurement by the detection unit 11 be performed under the same road surface conditions and speed conditions until the predetermined number of tire rotations is reached. However, if the predetermined number of tire rotations is not reached even after one month has passed since the initial measurement, the measurement result at that time is treated as a provisional measurement result. Furthermore, if the predetermined number of tire rotations is not reached, a more suitable area may be reset based on road surface conditions and speed conditions similar to those of the previous measurement and the current driving history.

[0054] Fig. 3 shows a modified example of the procedure of the detection method using the tire information detection device according to the embodiment of the present invention. While Fig. 2 shows an example in which a single determination condition is used by the determination unit 15, Fig. 3 shows an example in which multiple determination conditions are used. In Fig. 3, the procedure from step S1 to step S2 is the same as in Fig. 2. Note that Fig. 3 starts from a state in which the detection unit 11 mounted on the tire information detection device 10 is not performing any measurements.

[0055] Following step S2, in steps S31 to S33, the determination unit 15 performs determinations A to C, respectively. The determination unit 15 has a plurality of determination conditions A to C. For example, if the determination condition A is set to an index value of the accident risk for each region, the determination condition B is set to an index value of the measurement frequency of the detection unit 11, and the determination condition C is set to the presence or absence of a measurement history by the detection unit 11, the determination unit 15 determines whether the current location is included in a region that matches each of the determination conditions A to C. If the current location is included in a region that matches any of the determination conditions A to C, the process proceeds to step S4. If the current location is not included in a region that matches any of the determination conditions, the process returns to step S1. In step S4, the control unit 16 of the tire information detection device 10 controls the detection unit 11 to start measurement. Note that while the current location is included in a region that matches any of the determination conditions A to C, the detection unit 11 continues to measure. However, if the current location is no longer included in a region that matches any of the determination conditions A to C, the detection unit 11 ends its measurement.

[0056] In this way, the judgment unit 15 has at least two judgment conditions, and by using at least two judgment conditions depending on the tire information to be detected, it is possible to achieve both a long lifespan for the power supply unit 12 and the detection of tire information at the appropriate time and place.

[0057] FIG. 4 shows a pneumatic tire (tire T) whose tire information is detected by the tire information detection device 10 according to the embodiment of the present invention.

[0058] As shown in FIG. 4, the tire T includes a tread portion 1 extending in the tire circumferential direction and forming an annular shape, a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3, 3 arranged radially inward of the sidewall portions 2.

[0059] A carcass layer 4 is mounted between the pair of bead portions 3, 3. This carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the inside to the outside of the tire around a bead core 5 arranged in each bead portion 3. A bead filler 6 made of a rubber composition and having a triangular cross section is arranged on the outer periphery of the bead core 5. An inner liner layer 9 is arranged in the region between the pair of bead portions 3, 3 on the tire inner surface Ts. This inner liner layer 9 forms the tire inner surface Ts.

[0060] On the other hand, multiple belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include multiple reinforcing cords that are inclined with respect to the tire circumferential direction, and are arranged so that the reinforcing cords cross each other between the layers. In the belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set to a range of 10° to 40°, for example. Steel cords are preferably used as the reinforcing cords of the belt layers 7. At least one belt cover layer 8 is arranged on the outer peripheral side of the belt layer 7, with the aim of improving high-speed durability, and the reinforcing cords are arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction. As the reinforcing cords of the belt cover layer 8, organic fiber cords such as nylon and aramid are preferably used.

[0061] The above-described tire internal structure is a typical example of a pneumatic tire, but is not limited to this.

[0062] In the pneumatic tire, a tire information detection device 10 is attached to the tire inner surface Ts. This tire information detection device 10 constitutes a single sensor module. The tire information detection device 10 is mounted inside a hollow housing and includes components such as a detection unit 11, a power supply unit 12, a position information detection unit 13, an additional information acquisition unit 14, a determination unit 15, and a control unit 16, and is fixed to the tire inner surface Ts via the housing. [Explanation of symbols]

[0063] 1 Tread section 2 Sidewall 3 Bead section 10 Tire information detection device 11 Detection unit 12 Power supply section 13 Location information detection unit 14 Additional information acquisition unit 15 Judgment section 16 Control Unit

Claims

1. A tire information detection device detects tire information including at least one of tire wear, tire deformation, road surface condition, tire contact condition, tire failure, tire running history, tire load condition, and friction coefficient, a power supply unit that supplies power to the detection unit; a position information detection unit that detects position information of the tire or the vehicle; an additional information acquisition unit that acquires additional information linked to the position information; a determination unit that determines whether a current position specified based on the position information is included in an area that matches a determination condition extracted from the additional information; and a control unit that controls measurement by the detection unit based on a determination result by the determination unit, a calculation unit for calculating an index value of the risk of accidents occurring for each region based on the number of accidents included in the additional information, wherein the determination unit uses the index value of the risk of accidents occurring for each region as a determination condition, and the control unit controls the measurement by the detection unit based on the index value of the risk of accidents occurring in the region that includes the current location.

2. 2. The tire information detection device according to claim 1, wherein the determination unit has at least two determination conditions, and uses the at least two determination conditions depending on the tire information to be detected.

3. 3. The tire information detection device according to claim 1, wherein the tire information includes tire wear, the determination unit uses information related to tire wear included in the additional information as a determination condition, and measurement by the detection unit is repeated until the number of tire rotations reaches 10 or more rotations.

4. 4. The tire information detection device according to claim 1, further comprising a measurement frequency calculation unit that calculates an index value of the measurement frequency of the detection unit based on environmental information included in the additional information, wherein the determination unit uses the index value of the measurement frequency of the detection unit as a determination condition, and the control unit controls the measurement of the detection unit based on the index value of the measurement frequency of the detection unit in an area that includes the current location.

5. The tire information detection device according to any one of claims 1 to 4, further comprising an image comparison calculation unit that compares a pre-recorded image of the vehicle's surroundings included in the additional information with an image taken while the vehicle is in motion to calculate a match rate of the images, wherein the determination unit uses the match rate of the images as a determination condition, and the control unit controls the measurement of the detection unit based on the match rate of the images in an area that includes the current location.

6. The tire information detection device according to any one of claims 1 to 5, further comprising a measurement history recording unit that records the measurement history of the detection unit at the current position identified based on the position information, wherein the determination unit uses the presence or absence of the measurement history of the detection unit as a determination condition, and the control unit controls the measurement of the detection unit based on the presence or absence of the measurement history of the detection unit in an area that includes the current position.

7. 7. The tire information detection device according to claim 1, further comprising: a danger avoidance behavior recording unit that records information about danger avoidance behavior at a current location identified based on the position information; and a danger index calculation unit that calculates a danger index value for each area based on the information about the danger avoidance behavior, wherein the determination unit uses the danger index value for each area as a determination condition, and the control unit controls measurement by the detection unit based on the danger index value for the area that includes the current location.

8. A tire information detection device that detects tire information including at least one of tire wear, tire deformation, road surface condition, tire contact condition, tire failure, tire running history, tire load condition, and friction coefficient, a power supply unit that supplies power to the detection unit; a position information detection unit that detects position information of the tire or the vehicle; an additional information acquisition unit that acquires additional information linked to the position information; a determination unit that determines whether a current position specified based on the position information is included in an area that matches a determination condition extracted from the additional information; and a control unit that controls measurement by the detection unit based on a determination result by the determination unit, a comparison calculation unit that compares a pre-recorded image of the vehicle's surroundings included in the additional information with an image taken while the vehicle is in motion to calculate a match rate of the images, the determination unit using the match rate of the images as a condition for determination, and the control unit controlling the measurement of the detection unit based on the match rate of the images in an area that includes the current location.

9. A tire information detection device that detects tire information including at least one of tire wear, tire deformation, road surface condition, tire contact condition, tire failure, tire running history, tire load condition, and friction coefficient, a power supply unit that supplies power to the detection unit; a position information detection unit that detects position information of the tire or the vehicle; an additional information acquisition unit that acquires additional information linked to the position information; a determination unit that determines whether a current position specified based on the position information is included in an area that matches a determination condition extracted from the additional information; and a control unit that controls measurement by the detection unit based on a determination result by the determination unit, a risk avoidance behavior recording unit that records information about risk avoidance behavior at a current location identified based on the position information; and a risk index calculation unit that calculates a risk index value for each area based on the information about the risk avoidance behavior, wherein the determination unit uses the risk index value for each area as a determination condition, and the control unit controls measurements by the detection unit based on the risk index value for the area that includes the current location.

Images