Data processing apparatus, data processing method, and program

Abstract

To improve accuracy in measurement of inside-tire temperatures.SOLUTION: A data processing device 20 comprises a control unit. The control unit: acquires inside-tire temperature data indicating inside-tire temperatures measured by sensors 40 each attached to a rim 13 of each wheel 12 of a vehicle 11; acquires outside-air temperature data indicating an outside-air temperature; determines a movement status of the vehicle 11; and corrects values of the inside-tire temperatures indicated by the acquired inside-tire temperature data according to the outside-air temperature indicated by the acquired outside-air temperature data and the determined movement status.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a data processing device, a data processing method, and a program. [Background technology]

[0002] Patent Document 1 discloses a TPMS receiver. "TPMS" is an abbreviation for tire pressure monitoring system. The receiver disclosed in Patent Document 1 intermittently receives an information signal including information on the tire pressure from a sensor unit attached to each tire. The sensor unit detects the tire temperature. The sensor unit transmits the detection result included in an information signal. Based on the tire temperature included in the received information signal, the receiver corrects the tire pressure included in the same signal to a tire pressure that is free of the effects of changes in tire temperature. The receiver determines whether or not a sudden decrease in tire pressure has occurred based on the corrected tire pressure. The receiver issues a warning when it determines that a sudden decrease in tire pressure has occurred. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-218582 A [Patent Document 2] JP 2021-195091 A Summary of the Invention [Problem to be solved by the invention]

[0004] One type of TPMS sensor is a rim-band sensor that is attached to the rim of the wheel. Rim-band sensors dissipate heat through the rim. Therefore, there is a discrepancy between the temperature measured by the TPMS sensor and the actual temperature inside the tire. This discrepancy can be a factor in reducing the accuracy of measuring the tire internal pressure.

[0005] An object of the present disclosure is to improve the accuracy of measuring the temperature inside a tire. [Means for solving the problem]

[0006] Several aspects of the disclosure are set forth below.

[0007] (1) obtaining internal tire temperature data indicative of an internal tire temperature measured by a sensor attached to a wheel rim of the vehicle; Obtaining outside temperature data indicating the outside temperature; Determining a movement status of the vehicle; The value of the tire inside temperature indicated by the acquired tire inside temperature data is corrected according to the outside air temperature indicated by the acquired outside air temperature data and the determined moving situation. A data processing device comprising a control unit. This embodiment can improve the measurement accuracy of the temperature inside the tire.

[0008] (2) The control unit is acquiring location data indicative of a location of the vehicle; The data processing device according to (1), further comprising: determining a speed of the vehicle as the moving status by referring to the position data. This aspect enables correction according to the vehicle speed, thereby further improving the accuracy of measuring the temperature inside the tire.

[0009] (3) A communication unit that communicates with a positioning device that measures the position of the vehicle using a signal received from a satellite, The data processing device according to (2), wherein the control unit acquires the position data from the positioning device via the communication unit. In this manner, the vehicle speed can be accurately determined.

[0010] (4) The data processing device described in (1), wherein the control unit determines whether the vehicle is moving or stopped as the movement status depending on whether the time change in the tire temperature indicated by the tire temperature data is positive or negative. This aspect allows for improved accuracy in measuring the temperature inside the tire without acquiring position data.

[0011] (5) A communication unit that communicates with a server device that provides meteorological information, The control unit is acquiring location data indicative of a location of the vehicle; The data processing device according to any one of (1) to (4), wherein data indicating the outside temperature at a location indicated by the location data is obtained from the server device via the communication unit as the outside temperature data. This aspect enables correction according to the outside air temperature at the vehicle location, thereby further improving the accuracy of measuring the tire internal temperature.

[0012] (6) The communication unit further communicates with a positioning device that measures the position of the vehicle using a signal received from a satellite, The data processing device according to (5), wherein the control unit acquires the position data from the positioning device via the communication unit. According to this aspect, it is possible to accurately identify the vehicle position and then to identify the outside air temperature at the vehicle position.

[0013] (7) A communication unit that communicates with a server device that provides meteorological information, The data processing device according to any one of (1) to (4), wherein the control unit acquires data indicating the outside temperature of a pre-specified country or region from the server device via the communication unit as the outside temperature data. This aspect allows for improved accuracy in measuring the temperature inside the tire without acquiring position data.

[0014] (8) The control unit is determining the material of the rim by referring to relationship data showing the relationship between past internal tire pressure and internal tire temperature; The data processing device according to any one of (1) to (7), further comprising: a parameter for correcting the tire internal temperature data being selected according to the determined material. This embodiment allows for correction according to the rim material, thereby further improving the accuracy of measuring the temperature inside the tire.

[0015] (9) The data processing device according to (8), wherein the control unit uses different parameters when correcting the tire internal temperature data at least when the material is iron and when the material is aluminum. This aspect can further improve the measurement accuracy of the temperature inside the tire when at least the rim is made of iron or aluminum.

[0016] (10) The data processing device according to any one of (1) to (9), wherein the control unit detects a drop in tire internal pressure by using the corrected value of the tire internal temperature. This aspect makes it possible to improve the accuracy of detecting slow leaks.

[0017] (11) a data processing device obtaining in-tire temperature data indicative of an in-tire temperature measured by a sensor mounted on a wheel rim of the vehicle; The data processing device acquires outside air temperature data indicative of an outside air temperature; The data processing device determines a moving status of the vehicle; The data processing device corrects a value of the tire inside temperature indicated by the acquired tire inside temperature data according to an outside air temperature indicated by the acquired outside air temperature data and the determined moving situation. Data processing methods, including: This embodiment can improve the measurement accuracy of the temperature inside the tire.

[0018] (12) The data processing method according to (11), further comprising the data processing device detecting a drop in tire internal pressure using the corrected value of the tire internal temperature. This aspect makes it possible to improve the accuracy of detecting slow leaks.

[0019] (13) obtaining internal tire temperature data indicative of an internal tire temperature measured by a sensor mounted on a wheel rim of the vehicle; obtaining outside temperature data indicative of an outside temperature; Determining a movement status of the vehicle; correcting the value of the tire inside temperature indicated by the acquired tire inside temperature data according to the outside air temperature indicated by the acquired outside air temperature data and the determined moving situation; A program that causes a computer to perform operations including: This embodiment can improve the measurement accuracy of the temperature inside the tire. Effect of the Invention

[0020] According to the present disclosure, it is possible to improve the measurement accuracy of the temperature inside a tire. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a detection system according to an embodiment of the present disclosure. [Diagram 2] 1 is a graph showing an example of a PT distribution of the temperature inside a tire measured by a sensor. [Diagram 3] 4 is a graph showing an example of hysteresis of the temperature inside a tire measured by a sensor. [Figure 4] 11 is a graph showing an example of a correction result obtained by performing hysteresis correction. [Diagram 5] 13 is a graph showing another example of a correction result obtained by performing hysteresis correction. [Figure 6] FIG. 1 is a diagram showing a presumed mechanism. [Figure 7] 1 is a graph showing an example of an improved PT distribution according to an embodiment of the present disclosure. [Figure 8] 1 is a block diagram showing a configuration of a data processing device according to an embodiment of the present disclosure. [Figure 9] 1 is a flowchart illustrating an operation of a data processing device according to an embodiment of the present disclosure. [Figure 10A] 11 is a graph showing an example of speed-dependent time constant variation for application when the vehicle speed can be accurately determined; [Figure 10B] 11 is a graph showing an example of a speed-dependent change in time constant that is applied when the vehicle speed cannot be accurately determined. [Figure 10C] 11 is a graph showing an example of time series changes in outside air temperature applied when the vehicle position can be accurately identified. [Figure 10D] 11 is a graph showing an example of time series changes in outside air temperature applied when the vehicle position cannot be accurately identified. [Figure 11A] 1 is a graph showing an example of the relationship between tire internal pressure and tire internal temperature when a steel wheel is used. [Figure 11B] 1 is a graph showing an example of the relationship between tire internal pressure and tire internal temperature when an aluminum wheel is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0023] In each drawing, the same or corresponding parts are denoted by the same reference numerals. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0024] The configuration of a detection system 10 according to this embodiment will be described with reference to FIG.

[0025] The detection system 10 includes a data processing device 20, at least one on-vehicle device 30, and at least one sensor 40. The data processing device 20 is capable of communicating with the on-vehicle device 30 via a network 50. In the example shown in FIG. 1, one on-vehicle device 30 is mounted on a vehicle 11, and two or more sensors 40 are mounted on rims 13 of corresponding wheels 12 of the vehicle 11. The on-vehicle device 30 is capable of wireless communication with each of the sensors 40.

[0026] The data processing device 20 is a device that corrects data related to the air pressure of the tires 14 of the vehicle 11 received from the in-vehicle device 30 based on data related to the temperature of the tires 14 of the vehicle 11 received from the in-vehicle device 30. In this embodiment, the data processing device 20 is a server computer such as a cloud server, but may be a general-purpose computer such as a PC, a microcomputer mounted on a mobile device such as a smartphone or a tablet, or a dedicated computer. "PC" is an abbreviation for personal computer. The data processing device 20 may be integrated with the in-vehicle device 30, for example, a microcomputer mounted on the in-vehicle device 30. Alternatively, the data processing device 20 may be integrated with the sensor 40, for example, a microcomputer mounted on the sensor 40.

[0027] The in-vehicle device 30 is a device that transmits data related to the air pressure and temperature of the tires 14 of the vehicle 11 received from the sensor 40 to the data processing device 20. The in-vehicle device 30 may be an ECU that is pre-installed in the vehicle 11, or may be an external device that is later installed in the vehicle 11. "ECU" is an abbreviation for electronic control unit. The in-vehicle device 30 may be replaced by a mobile device such as a smartphone or tablet that has the same functions as the in-vehicle device 30 and can be connected to the vehicle 11.

[0028] The sensor 40 is a device that measures the air pressure and temperature of a tire 14 of the vehicle 11. The sensor 40 is a TPMS sensor that can be attached to the rim 13 of the wheel 12 of the vehicle 11, such as a rim band type sensor.

[0029] Network 50 includes the Internet, at least one WAN, at least one MAN, or any combination thereof. "WAN" is an abbreviation for wide area network. "MAN" is an abbreviation for metropolitan area network. Network 50 may include at least one wireless network, at least one optical network, or any combination thereof. The wireless network may be, for example, an ad-hoc network, a cellular network, a wireless LAN, a satellite communication network, or a terrestrial microwave network.

[0030] In this embodiment, the detection system 10 further includes at least one positioning device 60. The data processing device 20 can communicate with the positioning device 60 via a network 50. In the example shown in FIG. 1, one positioning device 60 is mounted on the vehicle 11.

[0031] The positioning device 60 is a device that measures the position of the vehicle 11 using signals received from satellites 80. The positioning device 60 includes at least one GNSS receiver. "GNSS" is an abbreviation for global navigation satellite system. GNSS is, for example, GPS, QZSS, BDS, GLONASS, or Galileo. "GPS" is an abbreviation for Global Positioning System. "QZSS" is an abbreviation for Quasi-Zenith Satellite System. QZSS satellites are called quasi-zenith satellites. "BDS" is an abbreviation for BeiDou Navigation Satellite System. "GLONASS" is an abbreviation for Global Navigation Satellite System.

[0032] In this embodiment, the detection system 10 uses a server device 70. The data processing device 20 is capable of communicating with the server device 70 via a network 50.

[0033] The server device 70 is a device that provides meteorological information. The server device 70 may be a server operated by a public institution such as the Meteorological Agency, or may be a server operated by a private institution such as a weather company.

[0034] The present embodiment will be outlined with reference to FIG. 2 to FIG.

[0035] In the detection system 10, the tire internal pressure and tire internal temperature are measured at regular intervals, such as every few minutes. The measurement results are transmitted by radio waves to the in-vehicle device 30 and further to the data processing device 20 via the network 50.

[0036] The data processing device 20 does not simply detect low pressure, but calculates the time change and issues an alert early when it is determined that the air leak rate is high and that the internal pressure is likely to become low in the future. Therefore, the vehicle 11 can be moved and serviced before the tire internal pressure becomes low, preventing operation stoppage. Air leaks are generally calculated by calculating both pressure and temperature, and converting the pressure into a constant temperature equivalent based on the nature of air that pressure increases as temperature increases, specifically Boyle's law, and then calculating the time change rate, i.e., the speed at which air escapes. However, it is generally known that the temperature is inaccurate in rim-band type TPMS equipment, which is relatively inexpensive, and temperature correction is required.

[0037] In this embodiment, two measures are taken to address the inaccuracy of temperature. One is to take into consideration the time difference between pressure and temperature. Pressure is transmitted immediately, but temperature is transmitted with a delay. Therefore, for example, a similar measure to that disclosed in Patent Document 2 is taken. The other is to take into consideration the transfer of heat to the sensor 40 and the release of heat from the sensor 40. The time history of the temperature inside the tire is estimated from the time history of the sensor temperature so that the temperature inside the tire to be measured is the temperature inside the tire to be measured, not the temperature at the location where the sensor 40 is installed. Specifically, an idea similar to the "observer" in control engineering is applied to the rim band type sensor.

[0038] FIG. 2 shows a theoretical line 91 and an actual PT distribution 92, with the vertical axis representing the temperature inside the tire and the horizontal axis representing the tire internal pressure. According to Boyle's law, PV=nRT, and since n, R, and V are constant if there is no leakage, P and T are proportional in an ideal rim-band type sensor. In other words, it can be assumed that PV=nRT is almost true on the theoretical line 91. That is, T can be estimated from P. In contrast, in the actual PT distribution 92, the temperature measured by the rim-band type sensor is inaccurate. It can be assumed that the sensor 40 is cooled by the outside air via the rim 13. In other words, it can be assumed that the measured value of the internal pressure is accurate given the rim-band type structure, but the measured value of the temperature contains an error.

[0039] Figure 3 shows the time change of the rim band type sensor. When viewed over time, there is no delay in the internal pressure, so it is strongly suspected that the temperature is transmitted with a delay. In other words, hysteresis 93 is visible, and a delay in the transmission of temperature is suspected. For example, the temperature time series data is delayed by 5 minutes from the pressure time series data. Therefore, as the first countermeasure, a correction such as that disclosed in Patent Document 2 is performed.

[0040] FIG. 4 shows the correction result 94. After the hysteresis 93 correction is performed, the next thing seen is heat dissipation through the rim 13 corresponding to the temperature difference with the outside air temperature, that is, the phenomenon of a drop in the measured temperature. The temperature measured by the rim band type sensor tends to differ more from the theoretical value as it deviates from the outside air temperature. Therefore, it can be assumed that heat is dissipated through the rim 13 in response to the difference in the outside air temperature. The effect of heat dissipation differs depending on the wind hitting the rim 13. The correction result 94 shown in FIG. 4 is for a case in which the vehicle 11 starts moving after the temperature inside the tire has cooled down to almost the same as the outside air temperature, and moves for a certain amount of time.

[0041] FIG. 5 shows another correction result 94A. This correction result 94A is for a case where the vehicle 11 is repeatedly moving and stopping intermittently. If the moving speed of the vehicle 11 decreases, the wind does not reach the rim 13, the heat dissipation capacity decreases, and the deviation becomes smaller. However, even if the vehicle 11 stops, heat is still dissipated, so the deviation does not become zero. In fact, when the data of the rim band type sensor was analyzed before and after it was stopped, it was observed that the temperature returns to a line different from the heating during movement when the vehicle 11 stops. In other words, it was found that the wind does not reach the rim 13, it becomes difficult to dissipate heat, and the sensor temperature approaches the temperature inside the tire.

[0042] An approximation based on the theory of heat dissipation can be considered. From the theory of heat dissipation, it is known that not only temperature difference but also air volume affects thermal conductivity. Therefore, it is considered that the amount of heat dissipation is proportional to the difference between the temperature inside the tire and the outside air temperature, and also to the sum of the moving speed and the offset. The proportionality coefficient and offset value can be determined by fitting from actual data.

[0043] It is possible to model the temperature of the sensor 40. It is possible to use two types of variables, the temperature inside the tire and the measured temperature, and perform correction by finding the temperature inside the tire from the measured temperature.

[0044] FIG. 6 shows the assumed mechanism. The rubber 15 such as the tread is the heat generating part. As a heating element, the temperature of the air 16 inside the tire to be measured is gradually transmitted to the sensor element through the case of the sensor 40. The amount of heat is proportional to the difference between the temperature of the air 16 inside the tire and the temperature of the sensor 40. The rim 13 mediates the heat dissipation. Cooling is performed by the outside air 17 according to the wind speed and the temperature difference. That is, as a heat dissipation element that becomes measurement noise, the temperature of the sensor 40 is dissipated so that it approaches the temperature of the outside air 17 through the rim 13, which has good thermal conductivity. The amount of heat dissipation can be considered as the product of the thermal conductivity and the temperature difference. The thermal conductivity depends on the strength of the wind hitting the rim 13. For example, the thermal conductivity is low when stopped and high when moving at high speed. The temperature difference corresponds to the difference between the temperature of the sensor 40 and the temperature of the outside air 17.

[0045] Since this mechanism can be expressed by a differential equation, it is possible to perform an approximate calculation by calculating the differential equation or, for convenience, a discrete recurrence formula for computer processing. The data other than TPMS used in this mechanism include speed data obtained using GNSS data and outside temperature data extracted from weather information for the area identified using GNSS data. Both data are used as options to improve accuracy. In other words, approximate calculation is possible even if neither data is available.

[0046] Therefore, as a second measure, a correction calculation is performed to estimate the temperature inside the tire from the measured temperature using a discretized and simplified calculation method similar to an observer in control engineering. Specifically, the temperature inside the tire is calculated using the following algorithm.

[0047] When the time series of the temperature inside the tire is Ti(t) and the unit of t is minutes, Ti(t+1)=Ti(t)+Ti_diff(t) is calculated. Instead of integrating the temperature inside the tire, it is calculated and discretized in one-minute units for convenience. When the measured temperature is Ts(t) and the outside air temperature is To(t), the initial value Ti(0)=To(0) or Ts(0). When the vehicle 11 has been stopped for a sufficiently long time, the outside air temperature, the measured temperature, and the temperature inside the tire become equal. When the heating time constant is α, the difference Ti_diff(t)=α(Ti_guess(t)-Ti(t)). For example, α is 0.25 / min. If the change in the measured temperature over time is Ts_diff(t)=Ts(t)-Ts(t-1), the difference between the measured temperature and the outside air temperature is Ts2o(t)=Ts(t)-To(t), the time constant of the transfer from the air in the tire 16 to the sensor 40 is β, the speed of the vehicle 11 is v(t), and the time constant of the transfer from the sensor 40 to the outside air 17 is γ(v(t)), then Ti_guess(t)=Ts(t)+(Ts_diff(t)+Ts2o·γ(v(t))) / β. For example, β is 1 / 3.75 minutes. For example, γ(v(t)) depends on the speed, and is 1 / 30 minutes when Ts_diff is decreasing while the vehicle 11 is stopped, and is 1 / 15 minutes when Ts_diff is increasing while the vehicle 11 is moving.

[0048] In this embodiment, since GNSS data is available from the positioning device 60, the speed data is acquired using the GNSS data. That is, v(t) is obtained from the GNSS data. Then, γ(v(t)) is calculated from the relational equation between speed and heat dissipation, which is a linear function with an intercept. When GNSS data is not available from the positioning device 60 or the positioning device 60 is not available, whether the vehicle 11 is moving or stopped is determined based on the change in the measured temperature over time, i.e., whether the differential value is positive or negative, and the speed of the vehicle 11 when moving is regarded as a constant speed, and the two values ​​of heat dissipation when moving and heat dissipation when stopped are selectively used as γ(v(t)).

[0049] In this embodiment, since GNSS data is available from the positioning device 60, outside temperature data is extracted from weather information for the area identified using the GNSS data. That is, the location is identified in time series from the GNSS data, and To(t) is obtained from the weather information for the location at each time. If GNSS data is not available from the positioning device 60 or the positioning device 60 cannot be used, data such as the average monthly temperature for the country or region where the vehicle 11 usually travels, such as Japan or prefectures, is used as To(t).

[0050] According to the method for correcting the measured temperature of the rim band type sensor of this embodiment, it is expected that the above-mentioned two measures will achieve a temperature accuracy close to that of the patch type. As the first measure, a correction is made to remove the influence of the temperature transmission delay. As the second measure, a correction is made to remove the influence of the heat radiation according to the outside air temperature and the moving speed. Then, a slow leak judgment is made at an internal pressure equivalent to the standard temperature using the temperature value after the influence has been removed. In order to verify the effect of such a correction logic, in addition to removing the transmission delay, the heat radiation due to the outside air temperature and the moving speed was corrected using past actual TPMS data in which slow leaks have not occurred for a long time, and the improvement status was confirmed on the PT graph. As shown in FIG. 7, an improvement effect was obtained in which the PT distribution 92A approached the theoretical line 91.

[0051] The configuration of a data processing device 20 according to this embodiment will be described with reference to FIG.

[0052] The data processing device 20 includes a control unit 21, a storage unit 22, and a communication unit .

[0053] The control unit 21 includes at least one processor, at least one programmable circuit, at least one dedicated circuit, or any combination thereof. The processor is a general-purpose processor such as a CPU or GPU, or a dedicated processor specialized for a specific process. "CPU" is an abbreviation for central processing unit. "GPU" is an abbreviation for graphics processing unit. The programmable circuit is, for example, an FPGA. "FPGA" is an abbreviation for field-programmable gate array. The dedicated circuit is, for example, an ASIC. "ASIC" is an abbreviation for application specific integrated circuit. The control unit 21 executes processes related to the operation of the data processing device 20 while controlling each part of the data processing device 20.

[0054] The storage unit 22 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or any combination thereof. The semiconductor memory is, for example, a RAM, a ROM, or a flash memory. "RAM" is an abbreviation for random access memory. "ROM" is an abbreviation for read only memory. The RAM is, for example, an SRAM or a DRAM. "SRAM" is an abbreviation for static random access memory. "DRAM" is an abbreviation for dynamic random access memory. The ROM is, for example, an EEPROM. "EEPROM" is an abbreviation for electrically erasable programmable read only memory. The flash memory is, for example, an SSD. "SSD" is an abbreviation for solid-state drive. The magnetic memory is, for example, an HDD. "HDD" is an abbreviation for hard disk drive. The storage unit 22 functions, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 22 stores data used in the operation of the data processing device 20 and data obtained by the operation of the data processing device 20.

[0055] The communication unit 23 includes at least one communication module. The communication module is, for example, a module compatible with a wired LAN communication standard such as Ethernet (registered trademark), a wireless LAN communication standard such as IEEE802.11, or a mobile communication standard such as LTE, 4G standard, or 5G standard. "IEEE" is an abbreviation for Institute of Electrical and Electronics Engineers. "LTE" is an abbreviation for Long Term Evolution. "4G" is an abbreviation for 4th generation. "5G" is an abbreviation for 5th generation. The communication unit 23 communicates with the in-vehicle device 30, the positioning device 60, and the server device 70 via the network 50. The communication unit 23 receives data used in the operation of the data processing device 20 and transmits data obtained by the operation of the data processing device 20.

[0056] The functions of the data processing device 20 are realized by executing a program according to this embodiment on a processor serving as the control unit 21. That is, the functions of the data processing device 20 are realized by software. The program causes a computer to execute the operations of the data processing device 20, thereby causing the computer to function as the data processing device 20. That is, the computer functions as the data processing device 20 by executing the operations of the data processing device 20 in accordance with the program.

[0057] The program may be stored in a non-transitory computer-readable medium. Examples of the non-transitory computer-readable medium include a flash memory, a magnetic recording device, an optical disk, a magneto-optical recording medium, or a ROM. The program may be distributed, for example, by selling, transferring, or lending a portable medium such as an SD card, DVD, or CD-ROM on which the program is stored. "SD" is an abbreviation for Secure Digital. "DVD" is an abbreviation for digital versatile disc. "CD-ROM" is an abbreviation for compact disc read only memory. The program may be distributed by storing the program in the storage of a server and transferring the program from the server to another computer. The program may be provided as a program product.

[0058] A computer temporarily stores a program stored in a portable medium or transferred from a server in a main storage device. Then, the computer reads the program stored in the main storage device with a processor and executes processing according to the read program with the processor. The computer may read the program directly from a portable medium and execute processing according to the program. The computer may execute processing according to the received program each time a program is transferred from the server to the computer. Processing may be executed by a so-called ASP-type service that realizes functions only by execution instructions and result acquisition without transferring a program from the server to the computer. "ASP" is an abbreviation for application service provider. Programs include information used for processing by a computer and equivalent to a program. For example, data that is not a direct command to a computer but has the property of defining computer processing falls under " equivalent to a program.

[0059] A part or all of the functions of the data processing device 20 may be realized by a programmable circuit or a dedicated circuit as the control unit 21. In other words, a part or all of the functions of the data processing device 20 may be realized by hardware.

[0060] The operation of the data processing device 20 according to the present embodiment will be described with reference to Fig. 9. The operation described below corresponds to the data processing method according to the present embodiment. That is, the data processing method according to the present embodiment includes steps S1 to S6 shown in Fig. 9.

[0061] In S1, the control unit 21 acquires in-tire temperature data. The in-tire temperature data is data indicating the in-tire temperature Ts(t) measured by a sensor 40 attached to the rim 13 of the wheel 12 of the vehicle 11. Specifically, the control unit 21 acquires the in-tire temperature data from the sensor 40 via the communication unit 23 and the in-vehicle device 30.

[0062] In S2, the control unit 21 acquires outside air temperature data. The outside air temperature data is data indicating the outside air temperature To(t). Specifically, the control unit 21 acquires position data. The position data is data indicating the position of the vehicle 11. For example, the control unit 21 acquires the position data from the positioning device 60 via the communication unit 23. The position data corresponds to GNSS data. The control unit 21 acquires data indicating the outside air temperature at the position indicated by the acquired position data from the server device 70 via the communication unit 23 as the outside air temperature data. For example, if data on air temperature in one-hour units is acquired as the outside air temperature data, the time series change of the outside air temperature indicated by such data will be as shown in FIG. 10C. If the control unit 21 cannot acquire position data, it may acquire data indicating the outside air temperature of a pre-specified country or region from the server device 70 via the communication unit 23 as the outside air temperature data. For example, if data on the average monthly temperature in Japan or prefecture units is acquired as the outside air temperature data, the time series change of the outside air temperature indicated by such data will be as shown in FIG. 10D.

[0063] In S3, the control unit 21 determines the movement status of the vehicle 11. Specifically, the control unit 21 acquires position data. For example, the control unit 21 acquires the position data from the positioning device 60 via the communication unit 23. The control unit 21 determines the speed v(t) of the vehicle 11 as the movement status by referring to the acquired position data. When the control unit 21 acquires the position data in S2, the control unit 21 may use the position data acquired in S2. For example, if the speed v(t) is obtained from the GNSS data, the change in the speed-dependent time constant γ(v(t)) is as shown in FIG. 10A. When the control unit 21 cannot acquire the position data, the control unit 21 may determine whether the vehicle 11 is moving or stopped as the movement status depending on whether the time change of the tire inside temperature Ts(t) indicated by the tire inside temperature data acquired in S1 is positive or negative. For example, if the speed v(t) is considered to be a constant speed when the time change of the tire internal temperature Ts(t) is positive, and the speed v(t) is considered to be 0 when the time change of the tire internal temperature Ts(t) is negative, the speed-dependent time constant γ(v(t)) changes as shown in Fig. 10B. The control unit 21 may be notified of the speed v(t) from the vehicle 11.

[0064] In S4, the control unit 21 corrects the value of the tire inside temperature Ts(t) indicated by the tire inside temperature data acquired in S1, according to the outside air temperature To(t) indicated by the outside air temperature data acquired in S2 and the travel situation determined in S3. Specifically, the control unit 21 calculates Ti(0)=To(0) or Ts(0) when t=0, and calculates Ti(t+1)=Ti(t)+Ti_diff(t) when t>0.

[0065] In S5, the control unit 21 uses the value of the tire internal temperature Ti(t+1) corrected in S4 to determine whether a drop in tire internal pressure, a so-called slow leak, has occurred. If it is determined that a slow leak has occurred, that is, if a slow leak has been detected, step S6 is executed. On the other hand, if it is determined that a slow leak has not occurred, that is, if a slow leak has not been detected, step S1 is executed again.

[0066] In S6, the control unit 21 outputs an alert. For example, the control unit 21 transmits a notification that a slow leak has occurred as an alert to the in-vehicle device 30 via the communication unit 23. Upon receiving the alert, the in-vehicle device 30 displays the received alert on a display or outputs it as audio from a speaker. The display is, for example, an LCD or an organic EL display. "LCD" is an abbreviation for liquid crystal display. "EL" is an abbreviation for electro luminescent. After step S6, step S1 may be executed again.

[0067] According to this embodiment, the accuracy of the temperature measurement by the sensor 40 can be improved.

[0068] As a modified example of this embodiment, in S4, the control unit 21 may refer to the relational data to determine the material of the rim 13. The relational data is data showing the relationship between the past tire internal pressure and the tire internal temperature. For example, the relational data is stored in the storage unit 22 and is read out by the control unit 21. In this modified example, the control unit 21 uses different parameters for correcting the tire internal temperature data according to the determined material. For example, when correcting the tire internal temperature data, the control unit 21 uses different parameters at least when the material is iron and when the material is aluminum. When the wheel 12 is made of iron and aluminum, the aluminum wheel has a higher thermal conductivity, so the influence of heat dissipation has a stronger influence on the measured temperature. Specifically, when the wheel 12 is made of aluminum, the influence of heat dissipation is small when the temperature is decreasing, but the effect of heat dissipation is significant when the temperature is increasing, so it is desirable to implement a correction logic that takes such characteristics into account.

[0069] FIG. 11A shows a theoretical line 95A and an actual PT distribution 96A when the wheel 12 is made of steel, with the vertical axis representing the temperature inside the tire and the horizontal axis representing the internal tire pressure. The ratio of the slope to the theoretical line 95A corresponds to the heat dissipation rate. FIG. 11B shows a theoretical line 95B and an actual PT distribution 96B when the wheel 12 is made of aluminum, with the vertical axis representing the temperature inside the tire and the horizontal axis representing the internal tire pressure. The ratio of the slope to the theoretical line 95B corresponds to the heat dissipation rate. Comparing FIG. 11A and FIG. 11B, the heat dissipation rate is higher when the wheel 12 is made of aluminum than when it is made of steel. Therefore, the control unit 21 can determine the material of the rim 13 based on the difference in the heat dissipation rate.

[0070] The present disclosure is not limited to the above-mentioned embodiment. For example, two or more blocks shown in the block diagram may be integrated, or one block may be divided. Instead of executing two or more steps shown in the flowchart in chronological order as described, they may be executed in parallel or in a different order depending on the processing capacity of the device executing each step, or as necessary. Other modifications are possible without departing from the spirit of the present disclosure.

[0071] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] The SDGs have been proposed to realize a sustainable society. It is believed that an embodiment of the present disclosure can contribute to "No. 9 - Build a foundation for industry and technological innovation." [Explanation of symbols]

[0072] 10. Detection System 11 Vehicles 12 Wheels 13 Rims 14 Tires 15 Rubber 16 Air in tires 17 Outside Air 20 Data Processing Device 21 Control section 22 Memory section 23 Communications Department 30 Onboard equipment 40 Sensors 50 Network 60 Positioning Device 70 Server equipment 80 satellites 91,95A,95B theoretical line 92,92A,96A,96B PT distribution 93 Hysteresis 94,94A Correction result

Claims

1. obtaining internal tire temperature data indicative of an internal tire temperature measured by a sensor attached to a wheel rim of the vehicle; Obtaining outside temperature data indicating the outside temperature; Determining a movement status of the vehicle; The value of the tire inside temperature indicated by the acquired tire inside temperature data is corrected according to the outside air temperature indicated by the acquired outside air temperature data and the determined moving situation. A data processing device comprising a control unit.

2. The control unit is acquiring location data indicative of a location of the vehicle; The data processing device according to claim 1 , further comprising: a speed of the vehicle being determined as the moving condition by referring to the position data.

3. A communication unit that communicates with a positioning device that measures the position of the vehicle using a signal received from a satellite, The data processing device according to claim 2 , wherein the control unit acquires the position data from the positioning device via the communication unit.

4. 2 . The data processing device according to claim 1 , wherein the control unit determines whether the vehicle is moving or stopped as the moving state depending on whether a time change in the tire temperature indicated by the tire temperature data is positive or negative.

5. A communication unit that communicates with a server device that provides meteorological information, The control unit is acquiring location data indicative of a location of the vehicle; The data processing device according to claim 1 , wherein the outside air temperature data is data indicating the outside air temperature at the location indicated by the location data, and the data is obtained from the server device via the communication unit.

6. The communication unit further communicates with a positioning device that measures the position of the vehicle using a signal received from a satellite, The data processing device according to claim 5 , wherein the control unit acquires the position data from the positioning device via the communication unit.

7. A communication unit that communicates with a server device that provides meteorological information, The data processing device according to claim 1 , wherein the control unit acquires, as the outside air temperature data, data indicating the outside air temperature in a pre-specified country or region from the server device via the communication unit.

8. The control unit is determining the material of the rim by referring to relationship data showing the relationship between past internal tire pressure and internal tire temperature; The data processing device according to claim 1 , further comprising: a parameter for correcting the tire internal temperature data being selected according to the determined material.

9. 9. The data processing device according to claim 8, wherein the control unit uses different parameters when the material is iron and when the material is aluminum when correcting the tire internal temperature data.

10. The data processing device according to claim 1 , wherein the control unit detects a decrease in tire internal pressure by using the corrected value of the tire internal temperature.

11. a data processing device obtaining in-tire temperature data indicative of an in-tire temperature measured by a sensor mounted on a rim of a wheel of the vehicle; The data processing device acquires outside air temperature data indicative of an outside air temperature; The data processing device determines a moving status of the vehicle; The data processing device corrects a value of the tire inside temperature indicated by the acquired tire inside temperature data according to an outside air temperature indicated by the acquired outside air temperature data and the determined moving situation. Data processing methods, including:

12. The data processing method according to claim 11, further comprising the data processing device detecting a loss of internal tire pressure using the corrected value of internal tire temperature.

13. obtaining internal tire temperature data indicative of an internal tire temperature measured by a sensor mounted on a wheel rim of the vehicle; obtaining outside temperature data indicative of an outside temperature; Determining a movement status of the vehicle; correcting the value of the tire inside temperature indicated by the acquired tire inside temperature data according to the outside air temperature indicated by the acquired outside air temperature data and the determined moving situation; A program that causes a computer to perform operations including:

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