Tire condition management device, program, and tire condition management method

Abstract

To provide a tire condition management device, a program, and a tire condition management method capable of accurately correcting a deviation at the time of detecting a tire internal temperature.SOLUTION: A tire condition management device (10) includes an acquisition unit (131) that acquires a tire internal pressure and a tire internal temperature detected by a detection device mounted on a vehicle, and a calculation unit (132) that specifies a slope in a distribution of the tire internal temperature with respect to the tire internal pressure and corrects the acquired tire internal temperature using a calculation formula for temperature correction based on past data of the tire internal pressure and the tire internal temperature of a normal tire according to the specified slope.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a tire condition management device, a program, and a tire condition management method. [Background technology]

[0002] Conventionally, methods for managing the tire conditions of a vehicle while it is moving have been proposed. It has also been practiced to estimate the vehicle condition (for example, whether it is loaded or not) from the tire condition (for example, tire internal pressure). For example, Patent Document 1 corrects the detected tire internal pressure based on the detected tire temperature (tire internal temperature). This correction makes it possible to calculate the tire internal pressure at a specific temperature, eliminating the influence of temperature rises that occur during driving, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-218582 Summary of the Invention [Problem to be solved by the invention]

[0004] The method of Patent Document 1 uses a calculation formula based on Boyle's law to correct the internal tire pressure. It is known that the detected internal tire temperature can have large errors depending on the measurement position on the tire or the detection method. For example, the internal tire temperature detected by a temperature sensor attached to the rim of a vehicle wheel has large errors due to the influence of heat radiation from the rim. For example, even if the method of Patent Document 1 performs correction based on the internal tire temperature detected by the temperature sensor attached to the rim, accurate internal tire pressure cannot be obtained due to the influence of errors. Therefore, even if the vehicle's load status is estimated from such internal tire pressure, the estimation result will be inaccurate.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a tire condition management device, a program, and a tire condition management method that can accurately correct deviations in the detection of tire internal temperatures. [Means for solving the problem]

[0006] (1) A tire condition management device according to an embodiment of the present disclosure includes: an acquisition unit that acquires the tire internal pressure and tire internal temperature detected by a detection device mounted on the vehicle; and a calculation unit that identifies a gradient in the distribution of the tire internal temperature relative to the tire internal pressure, and corrects the acquired tire internal temperature according to the identified gradient using a temperature correction formula based on past data of the tire internal pressure and the tire internal temperature of a normal tire. This configuration makes it possible to accurately correct deviations in the detection of the tire internal temperature.

[0007] (2) As one embodiment of the present disclosure, in (1), The temperature inside the tire is detected by a detection device having a temperature sensor attached to the rim of the wheel of the vehicle. With this configuration, even if a temperature sensor that detects the temperature inside the tire with a large deviation due to heat radiation is used, it is possible to obtain an estimated temperature that is an actual value.

[0008] (3) As an embodiment of the present disclosure, in (1) or (2), The vehicle is a mining vehicle equipped with OR tires, which can be in a loaded state in which the vehicle is loaded with cargo at a state close to the maximum load capacity, and an empty state in which the vehicle is not loaded with cargo, The calculation unit uses the corrected internal tire temperature to calculate a converted pressure by converting the acquired internal tire pressure to pressure at a specific temperature, and determines the loaded state or the unloaded state of the vehicle based on the converted pressure. This configuration makes it possible to accurately determine whether a mining vehicle equipped with OR tires is loaded or not using the accurately corrected internal tire temperature.

[0009] (4) A program according to an embodiment of the present disclosure includes: Tire condition management device, Obtaining an internal tire pressure and an internal tire temperature detected by a detection device mounted on a vehicle; The method identifies the gradient in the distribution of the tire internal temperature relative to the tire internal pressure, and corrects the acquired tire internal temperature according to the identified gradient using a temperature correction formula based on past data of the tire internal pressure and tire internal temperature of normal tires. This configuration makes it possible to accurately correct deviations in the detection of the tire internal temperature.

[0010] (5) A tire condition management method according to an embodiment of the present disclosure includes: A tire condition management method executed by a tire condition management device, Obtaining an internal tire pressure and an internal tire temperature detected by a detection device mounted on a vehicle; Identifying a gradient in the distribution of the tire internal temperature relative to the tire internal pressure, and correcting the acquired tire internal temperature according to the identified gradient using a temperature correction formula based on past data of the tire internal pressure and the tire internal temperature of a normal tire. This configuration makes it possible to accurately correct deviations in the detection of the tire internal temperature. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide a tire condition management device, a program, and a tire condition management method that can accurately correct deviations in the detection of tire internal temperatures. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a tire condition management system including a tire condition management device according to an embodiment of the present disclosure. [Figure 2]FIG. 2 is another diagram showing an example of the configuration of the tire condition management system of FIG. [Figure 3] FIG. 3 is a diagram illustrating the relationship between the actually measured tire pressure and tire temperature. [Figure 4] FIG. 4 is a diagram for explaining the temperature correction in this embodiment. [Figure 5] FIG. 5 is a diagram for explaining the determination of whether a vehicle is loaded or not. [Figure 6] FIG. 6 is an example of a flowchart illustrating the processing of a tire condition management method according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] A tire condition management device 10 (see FIG. 1), a program, and a tire condition management method according to one embodiment of the present disclosure will be described below with reference to the drawings. In each drawing, identical or corresponding parts are designated by the same reference numerals. In the description of this embodiment, the description of identical or corresponding parts will be omitted or simplified as appropriate.

[0014] 1 and 2 are diagrams showing an example of the configuration of a tire condition management system. The tire condition management system includes a tire condition management device 10. Fig. 1 is a block diagram including an example of the internal configuration of the tire condition management device 10 and an example of the configuration of a device mounted on a vehicle 20. Fig. 2 shows the overall configuration of the tire condition management system.

[0015] The tire condition management device 10 manages the condition of a tire 30 mounted on a vehicle 20. The condition of the tire 30 includes at least changes in the internal pressure of the tire 30. The tire condition management device 10 can determine, for example, a puncture or slow leak of the tire 30 based on time-series changes in the internal tire pressure. A known method may be used to determine a puncture or slow leak. A slow leak and a puncture are phenomena in which, for example, damage to the tire 30 causes air to leak out of the tire, resulting in an insufficient air pressure. A puncture is a sudden air leak from the tire 30, resulting in a significant decrease in air pressure over a short period of time (e.g., 10 minutes). A slow leak is a leak from the tire 30 in which air pressure decreases at a rate that exceeds natural decompression, but is not as rapid as a puncture. The tire condition management device 10 may display changes in the internal tire pressure and the results of a puncture or slow leak determination on a display unit (display) so that the manager of the vehicle 20 can determine, for example, whether the tire 30 should be replaced or repaired. Repairing the tire 30 may include retreading, which involves scraping off the surface of the tread rubber of the tire 30 and applying new rubber for reuse.

[0016] In this embodiment, the tire condition management device 10 further determines whether the vehicle 20 is loaded. The determination of whether the vehicle 20 is loaded may be made by determining whether the vehicle 20 is loaded with almost the maximum load or almost zero load (empty).

[0017] Here, the vehicle 20 may be, for example, a passenger car, a truck, a bus, or a construction vehicle, and is not limited to a specific type of moving body. In this embodiment, the vehicle 20 is described as a mining vehicle equipped with OR (Off-the-Road) tires and used to transport minerals. Here, the mining vehicle is a dump truck or the like used in mining work, has a body that is significantly larger than that of a typical truck, and is a vehicle 20 that travels on rough, unpaved roads. Also, although only one vehicle 20 is shown in FIGS. 1 and 2 to avoid redundancy, the tire condition management system may be configured to include multiple vehicles 20.

[0018] Furthermore, when loading cargo (minerals) onto mining vehicles equipped with OR tires, operational efficiency is particularly important, and so the vehicle is often in one of two states: either loaded near its maximum load capacity, or empty. For such vehicles 20, there is a demand for a method for quickly and accurately determining whether the vehicle 20 is loaded or empty based on changes in tire pressure. OR tires have a larger thermal time constant than general truck tires or bus tires, and temperature changes due to loading or unloading of cargo appear slowly. Therefore, it is preferable to be able to determine whether the vehicle is loaded based solely on changes in tire pressure. The tire pressure used to determine whether the vehicle is loaded may be a converted pressure obtained by converting the acquired tire pressure to pressure at a specific temperature.

[0019] Here, the relationship PV=nRT (Boyle's law) holds for the tire 30. P is the internal tire pressure. V is the volume of the tire 30. n is the number of moles of gas inside the tire. R is the gas constant. T is the temperature inside the tire 30 (internal tire temperature). For a normal tire 30 without a puncture or slow leak, V and n do not change and can be treated as constants, so the relationship P∝T (P is proportional to T) holds. It is known that the detected internal tire temperature can have large errors depending on the measurement position or detection method on the tire 30. For example, the internal tire temperature detected by a temperature sensor attached to the wheel rim of the vehicle 20 has large errors due to the influence of heat radiation from the rim. Figure 3 is a diagram illustrating the relationship between the actually measured internal tire pressure and internal tire temperature. The internal tire temperature in Figure 3 is detected by a detection device 70 having a temperature sensor attached to the wheel rim of the vehicle 20. It can be seen that the distribution of the actual measured values ​​deviates from the straight line that represents the calculated value (theoretical value) when assuming P ∝ T due to errors. Therefore, even if the actual measured internal tire temperature is directly substituted into the relational equation PV = nRT, an accurate internal tire pressure cannot be obtained due to the influence of errors. Furthermore, even if, for example, the presence or absence of a load on the vehicle 20 is estimated from such internal tire pressure, the estimation result will be inaccurate. Here, distribution refers to a set of plots (point cloud) that represent a set of data on internal tire pressure and internal tire temperature detected simultaneously.

[0020] The tire condition management device 10 according to this embodiment can accurately correct deviations in the detection of tire internal temperatures by executing the processes of the tire condition management method described below. The tire condition management device 10 can obtain an estimated temperature as an actual value even in a configuration that uses a temperature sensor that has a large deviation in the detection of tire internal temperatures due to heat radiation.

[0021] Referring again to FIGS. 1 and 2, the tire condition management device 10 includes a communication unit 11, a memory unit 12, and a control unit 13. The control unit 13 includes an acquisition unit 131, a calculation unit 132, and an output unit 133. The tire condition management device 10 may be, for example, a computer in its hardware configuration. The computer may be a server computer or a portable computer such as a laptop or tablet. Details of the components of the tire condition management device 10 will be described later. In this embodiment, the tire condition management device 10 is a computer located away from the work site of the mining vehicle. Here, the tire condition management device 10 may not be a single device, but may be composed of multiple devices located in multiple locations and capable of transmitting and receiving data to and from each other via a network 40. In other words, multiple devices connected via a network 40 may function as a whole as the tire condition management device 10 shown in FIG. 1. Therefore, for example, the tire condition management device 10 may be, for example, composed of a single computer in its hardware configuration, or may be composed of multiple computers connected via a network 40. When the system is configured with multiple computers, the storage unit 12 may be a shared memory that can be accessed by each computer.

[0022] The tire condition management device 10 may constitute a tire condition management system together with devices (a detection device 70 and an on-board communication device 80) mounted on the vehicle 20 and connected via a network 40. The network 40 may be, for example, the Internet. The network 40 may also include, for example, a local area network (LAN). The tire condition management system may further include a terminal device 50 used by an administrator who manages the vehicle 20. The terminal device 50 may be, for example, a general-purpose mobile terminal such as a smartphone or a tablet terminal, but is not limited to these. The terminal device 50 may function as a display unit that displays the determination results output from the tire condition management device 10. The tire condition management system may also include a storage device 90 (a cloud-based storage device 90) on the network 40 as viewed from the tire condition management device 10 and the devices mounted on the vehicle 20. In this embodiment, the storage device 90 includes a database that stores information about the condition of the tire 30 detected by the detection device 70 mounted on the vehicle 20 as time-series data, linking the information to the vehicle 20 being detected. In this embodiment, the tire condition management device 10 acquires necessary information from the database via the network 40.

[0023] In this embodiment, the vehicle 20 includes a detection device 70 and an on-board communication device 80. The detection device 70 is a device or on-board system equipped with sensors that generates information about the condition of the tires 30. In this embodiment, the detection device 70 includes a tire pressure monitoring system (TPMS).

[0024] The tire pressure monitoring system monitors the internal pressure (internal tire pressure) of a tire 30 attached to a vehicle 20. The tire pressure monitoring system also monitors the temperature inside the tire 30 (internal tire temperature). The tire pressure monitoring system may be configured, for example, to include a sensor installed inside the tire 30, a processor that calculates and outputs the pressure of the tire 30 (internal tire pressure) based on the detected value of the sensor, and a memory that stores the detected value of the sensor. The sensor includes a pressure sensor and a temperature sensor. In this embodiment, the temperature sensor is attached to the rim of a wheel of the vehicle 20.

[0025] The on-vehicle communication device 80 is a device that outputs information about the state of the tire 30 detected by the detection device 70 so that the information is stored in a database. In this embodiment, the on-vehicle communication device 80 is realized by the communication function of a digital tachograph, but is not limited to this and may be, for example, a device dedicated to communication. In this embodiment, the on-vehicle communication device 80 outputs information including the internal tire pressure and internal tire temperature detected by the detection device 70, and this information is stored in a database in the storage device 90 on the cloud.

[0026] Here, when the tire condition management system is configured without the storage device 90, the storage unit 12 of the tire condition management device 10 may have a database.

[0027] The components of the tire condition management device 10 will be described in detail below. The communication unit 11 is configured to include one or more communication modules connected to the network 40. The communication unit 11 may include a communication module compatible with mobile communication standards such as 4G (4th Generation) and 5G (5th Generation). The communication unit 11 may include a communication module compatible with a wired or wireless LAN standard, for example.

[0028] The storage unit 12 is one or more memories. The memory may be, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like, but is not limited to these, and may be any memory. The storage unit 12 is, for example, built into the tire condition management device 10, but may also be configured to be accessed from outside by the tire condition management device 10 via any interface.

[0029] The storage unit 12 stores various data used in various calculations performed by the control unit 13. The storage unit 12 may also store results and intermediate data of various calculations performed by the control unit 13.

[0030] In this embodiment, the storage unit 12 may temporarily store various information obtained from the database of the storage device 90 on the cloud via the communication unit 11.

[0031] The control unit 13 is one or more processors. The processor may be, for example, a general-purpose processor or a dedicated processor specialized for a specific process, but is not limited to these and may be any processor. The control unit 13 controls the overall operation of the tire condition management device 10.

[0032] Here, the tire condition management device 10 may have the following software configuration: One or more programs used to control the operation of the tire condition management device 10 are stored in the memory unit 12. When the program stored in the memory unit 12 is read by the processor of the control unit 13, it causes the control unit 13 to function as an acquisition unit 131, a calculation unit 132, and an output unit 133.

[0033] The acquisition unit 131 acquires input data including the internal tire pressure and internal tire temperature of the tire 30 detected by the detection device 70 mounted on the vehicle 20. In this embodiment, the internal tire pressure and internal tire temperature are acquired as time-series data.

[0034] The calculation unit 132 identifies the gradient in the distribution of the internal tire temperature relative to the internal tire pressure. Then, the calculation unit 132 corrects the acquired internal tire temperature according to the identified gradient using a temperature correction formula based on past data of the internal tire pressure and internal tire temperature of a normal tire 30. A normal tire 30 is a tire 30 that is not punctured or has a slow leak and for which the relationship P∝T holds. A temperature correction formula (correction formula) can be obtained based on past data (actual data) of the internal tire pressure and internal tire temperature of a normal tire 30 stored in a database. That is, the value T obtained by inputting the internal tire pressure (actual measurement) in the actual data into the relationship PV=nRT is the "actual value and estimated temperature." Then, by correlating the internal tire temperature (actual measurement) with the calculated "actual value and estimated temperature," a correction formula for correcting the internal tire temperature (actual measurement) to the actual value and estimated temperature can be obtained.

[0035] FIG. 4 is a diagram for explaining temperature correction in this embodiment. The left diagram of FIG. 4 is similar to FIG. 3 and shows the distribution of actual measurement values. The center diagram of FIG. 4 is a diagram showing the above correction formula. When the internal tire temperature (actual measurement) is corrected to a "temperature estimated as an actual value" using the correction formula, a distribution like the one shown in the right diagram of FIG. 4 is obtained. In other words, the relationship between the corrected internal tire temperature and the internal tire pressure (actual measurement) is P∝T.

[0036] As shown in the left diagram of FIG. 4 , the distribution of actual measurement values ​​has a slope that does not satisfy the P∝T relationship (a slope that is not 1.0). Here, the slope indicates the tendency of the correspondence between internal tire temperature and internal tire pressure in the actual measurement values ​​(detected values). The slope varies depending on the combination of the temperature sensor type and the temperature sensor installation method. The temperature sensor installation method also includes differences in installation position. Different combinations of the temperature sensor type and the temperature sensor installation method result in different effects on the tire internal temperature due to heat radiation, resulting in different correction formulas. The calculation unit 132 calculates a correction formula for each slope based on the performance data and stores the formula in, for example, the memory unit 12. In the example of FIG. 4 , only the correction formula for the slope of 1.2 is shown, but correction formulas for other slopes, such as a slope of 1.5, are also calculated. The calculation unit 132 then identifies the slope in the distribution of actual measurement values ​​for the tire 30 being managed and performs temperature correction using the correction formula for the same slope. For example, when the calculation unit 132 determines that the slope is 1.5, it reads out the correction formula for the slope of 1.5 stored in the storage unit 12 and corrects the acquired tire internal temperature.

[0037] In this embodiment, the calculation unit 132 calculates a converted pressure (described later) from the tire internal pressure (actual measurement), assumes multiple slopes for the distribution using the converted pressure (a point cloud of tire internal temperature (actual measurement) and converted pressure), and calculates the difference (variance) from a line having each slope. The multiple slopes may be, for example, slopes that differ in increments of 0.1 from 1.1 to 1.5. The calculation unit 132 may then identify the slope by selecting the slope with the smallest variance. However, the method for identifying the slope is not limited. As another example, the calculation unit 132 may use the slope of a line obtained by the least squares method for the distribution of actual measurement values ​​(or the distribution using the converted pressure).

[0038] Furthermore, the calculation unit 132 may use the corrected internal tire temperature to calculate a converted pressure by converting the acquired internal tire pressure to pressure at a specific temperature (for example, 25°C), and may determine the loaded or unloaded state of the vehicle 20 based on the converted pressure. The calculation of the converted pressure may use the relational expression PV=nRT. Here, the vehicle 20 is a mining vehicle equipped with OR tires. As described above, the loading state of a mining vehicle can often be either a loaded state in which it is loaded with cargo close to its maximum load capacity, or an unloaded state in which it is not loaded with cargo.

[0039] FIG. 5 is a diagram for explaining the determination of whether the vehicle 20 is loaded. The left diagram in FIG. 5 shows the time change of the converted pressure in the conventional technology (i.e., technology that does not correct the tire internal temperature). In the conventional technology, errors in detecting the tire internal temperature are not corrected, so the converted pressure fluctuates widely due to the influence of the errors (it fluctuates within a range from P1 to P3). The right diagram in FIG. 5 shows the time change of the converted pressure in this embodiment. In this embodiment, errors in detecting the tire internal temperature are corrected, so the converted pressure does not fluctuate widely (it is within a range from P1 to P2). The calculation unit 132 may then use a threshold value, for example, a value between P1 and P2, to determine that the vehicle 20 is loaded if the converted pressure is equal to or greater than the threshold value, and determine that the vehicle 20 is unloaded if the converted pressure is less than the threshold value. The calculation unit 132 can accurately determine whether a mining vehicle equipped with OR tires is loaded using the accurately corrected tire internal temperature.

[0040] For example, another conventional technique is known that calculates the load by focusing on the difference between the measured internal pressure and a predetermined reference pressure. However, this conventional method is significantly affected by internal pressure adjustments performed during tire maintenance, making it difficult to accurately determine whether the vehicle is loaded. In contrast, this embodiment calculates the fluctuation range of the converted pressure (the range from P1 to P2) and sets the threshold value to a value between P1 and P2, thereby enabling accurate determination of whether the vehicle is loaded regardless of internal pressure adjustments (changes in the internal pressure level).

[0041] The output unit 133 may output the determination result of the calculation unit 132 (for example, whether the vehicle 20 is loaded or not) to a terminal device 50 or the like used by an administrator who manages the vehicle 20. The output unit 133 may process the determination result of the calculation unit 132 into, for example, a cumulative loading time or an operating rate so that it is easy for the viewer to understand, and output the processed data to the terminal device 50 or the like. Furthermore, when the calculation unit 132 determines a puncture or a slow leak, the output unit 133 may output a warning that there is a puncture or a slow leak to the terminal device 50 or the like. The administrator may plan or carry out repairs, etc., for the tire 30 that is the subject of the determination based on the displayed determination result.

[0042] 6 is an example of a flowchart showing the processing of a tire condition management method executed by the tire condition management device 10 according to this embodiment. By executing the processing of FIG. 6, the tire condition management device 10 can accurately correct deviations in the detection of tire internal temperatures. Furthermore, using the accurately corrected tire internal temperatures, it becomes possible to accurately determine whether a mining vehicle equipped with OR tires is loaded.

[0043] The acquisition unit 131 acquires the tire internal pressure and tire internal temperature of the tire 30 (step S1).

[0044] The calculation unit 132 identifies the gradient of the distribution of the internal tire temperature with respect to the internal tire pressure using the above method (step S2).

[0045] The calculation unit 132 corrects the acquired internal tire temperature according to the identified gradient using a correction formula based on the actual data of the internal tire pressure and internal tire temperature of normal tires 30 (step S3).

[0046] The calculation unit 132 uses the corrected internal tire temperature to calculate a converted pressure by converting the acquired internal tire pressure into a pressure at a specific temperature (step S4).

[0047] The calculation unit 132 determines whether the vehicle 20 is loaded (whether it is loaded or unloaded) using, for example, the threshold value (step S5).

[0048] Furthermore, the determination result of the calculation unit 132 may be output by the output unit 133 to a terminal device 50 used by an administrator who manages the vehicle 20, or the like.

[0049] As described above, the tire condition management device 10, program, and tire condition management method according to the present embodiment can accurately correct deviations in the detection of tire internal temperatures using the above-described configuration. Using the accurately corrected tire internal temperatures, it becomes possible to accurately determine whether a vehicle is loaded (loaded or unloaded), particularly for mining vehicles equipped with OR tires.

[0050] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that a person skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined into one or divided. The embodiments of the present disclosure can also be realized as a storage medium on which a program executed by a processor provided in an apparatus is recorded. It should be understood that these are also included in the scope of the present disclosure. Contribution to the Sustainable Development Goals (SDGs) led by the United Nations

[0051] The SDGs have been proposed to realize a sustainable society. One embodiment of the present disclosure is believed to be a technology that can contribute to "No. 9 Build resilient infrastructure for industry, innovation and other areas." [Explanation of symbols]

[0052] 10 Tire condition management device 11 Communications Department 12 Storage section 13 Control Unit 20 vehicles 30 tires 40 Network 50 Terminal Equipment 70 Detection Device 80 In-vehicle communication device 90 Storage device 131 Acquisition Department 132 Arithmetic section 133 Output section

Claims

1. an acquisition unit that acquires the tire internal pressure and tire internal temperature detected by a detection device mounted on the vehicle; a calculation unit that identifies a gradient in the distribution of the tire internal temperature relative to the tire internal pressure, and corrects the acquired tire internal temperature according to the identified gradient using a temperature correction formula based on past data of the tire internal pressure and the tire internal temperature of normal tires.

2. 2. The tire condition management device according to claim 1, wherein the tire internal temperature is detected by a detection device having a temperature sensor attached to a wheel rim of the vehicle.

3. The vehicle is a mining vehicle equipped with OR tires, which can be in a loaded state in which it is loaded with cargo at a state close to a maximum load capacity, and an empty state in which it is not loaded with cargo, 3. The tire condition management device according to claim 1, wherein the calculation unit calculates a converted pressure by converting the acquired tire internal pressure to a pressure at a specific temperature using the corrected tire internal temperature, and determines the loaded state or the unloaded state of the vehicle based on the converted pressure.

4. Tire condition management device, Obtaining an internal tire pressure and an internal tire temperature detected by a detection device mounted on a vehicle; and identifying a gradient in the distribution of the tire internal temperature relative to the tire internal pressure, and correcting the acquired tire internal temperature according to the identified gradient using a temperature correction formula based on past data of the tire internal pressure and the tire internal temperature of a normal tire.

5. A tire condition management method executed by a tire condition management device, Obtaining an internal tire pressure and an internal tire temperature detected by a detection device mounted on a vehicle; and correcting the acquired internal tire temperature in accordance with the identified gradient using a temperature correction formula based on past data of the internal tire pressure and the internal tire temperature of a normal tire.

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