Tire monitoring device and tire monitoring method

Abstract

To provide a tire monitoring device and a tire monitoring method capable of presenting useful information for making a user recognize a failure in a tire and the periphery of the tire at an early stage.SOLUTION: A tire monitoring device 30 includes an information acquiring unit 35a, a representative-value calculating unit 35c, and a display processing unit 35d. The information acquiring unit 35a acquires measurement data measured by an air pressure sensors 11 provided in the tires 1 mounted in a vehicle. The representative-value calculating unit 35c calculates representative air pressure for each predetermined period based on the measurement date acquired by the information acquiring unit 35a. The display processing unit 35d generates a graph showing a temporal transition of the representative air pressure calculated by the representative-value calculating unit 35c, and displays the graphs on a display device.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tire monitoring device and a tire monitoring method for managing tires mounted on a vehicle. [Background technology]

[0002] Tires mounted on a vehicle are set to an appropriate air pressure, and if the air pressure drops, the tires are filled with air as part of maintenance so that the appropriate air pressure is restored.

[0003] A conventional tire failure prediction system is described in Patent Document 1. This tire failure prediction system determines that there is a possibility of failure in the first tire when the temperature value of a first tire exceeds a predetermined threshold and the difference between the temperature value of the first tire and the temperature value of a second tire exceeds a predetermined first temperature difference threshold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-111126 Summary of the Invention [Problem to be solved by the invention]

[0005] In the tire failure prediction system described in Patent Document 1, when the outside air temperature is low, for example in winter, the possibility of a tire malfunction is determined by correcting the temperature value acquired by the temperature acquisition unit based on the air temperature detected by the air temperature sensor. The inventors have recognized that simply monitoring the tire temperature is insufficient to determine whether a malfunction has occurred in the tire and vehicle components around the tire.

[0006] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a tire monitoring device and a tire monitoring method that can present useful information to enable a user to recognize problems in or around a tire at an early stage. [Means for solving the problem]

[0007] A tire monitoring device according to one embodiment of the present invention comprises an information acquisition unit that acquires measurement data from an air pressure sensor attached to a tire mounted on a vehicle, a representative value calculation unit that calculates a representative air pressure at predetermined intervals based on the measurement data acquired by the information acquisition unit, and a display processing unit that generates a graph showing the time-dependent change in the representative air pressure calculated by the representative value calculation unit and displays it on a display device.

[0008] Another aspect of the present invention is a tire monitoring method, comprising: an information acquiring step of acquiring measurement data from air pressure sensors provided in tires mounted on a vehicle; a representative value calculating step of calculating a representative air pressure for each predetermined period based on the measurement data acquired in the information acquiring step; and a display processing step of generating a graph showing time-varying changes in the representative air pressure calculated in the representative value calculating step and displaying the graph on a display device. [Effects of the Invention]

[0009] According to the present invention, it is possible to present useful information to a user so that the user can recognize problems in or around the tire at an early stage. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing the overall configuration of a tire monitoring system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of the tire monitoring device. [Figure 3] 10 is a flowchart showing a procedure for graph display processing by the tire monitoring device. [Figure 4]1 is a graph showing an example of time-dependent changes in a representative tire air pressure Pr. [Figure 5] 10 is a graph showing another example of the change over time in the representative tire air pressure Pr. [Figure 6] FIG. 10 is a schematic diagram showing an example of displaying graphs of the time course of a representative air pressure Pr and a representative temperature Tr side by side. [Figure 7] FIG. 10 is a block diagram showing the functional configuration of a tire monitoring device according to a second embodiment. [Figure 8] 10 is a graph showing the time course of a representative temperature with the time point at which a malfunction occurred highlighted. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below based on preferred embodiments with reference to Figures 1 to 8. The same or equivalent components and members shown in each drawing are designated by the same reference numerals, and duplicate descriptions will be omitted where appropriate. The dimensions of the members in each drawing are enlarged or reduced as appropriate to facilitate understanding. Some members that are not important for explaining the embodiments will be omitted from the drawings.

[0012] (Embodiment 1) 1 is a schematic diagram showing the overall configuration of a tire monitoring system 100 according to embodiment 1. The tire monitoring system 100 includes a sensor 10, a vehicle measurement device 20, a tire monitoring device 30, and a user terminal device 40. The tire monitoring system 100 acquires and monitors measurement data such as the air pressure and temperature of tires 1 measured by the sensors 10 disposed on multiple tires 1 mounted on a vehicle 7.

[0013] The vehicles 7 are, for example, multiple transport trucks operated and managed by a transport company or the like. The tire monitoring device 30 of the tire monitoring system 100 acquires and monitors measurement data such as air pressure and temperature of multiple tires 1 mounted on each of the multiple vehicles 7. The tire monitoring device 30 may acquire and monitor measurement data such as air pressure and temperature of tires 1 for a single vehicle.

[0014] The tire monitoring device 30 calculates the representative tire pressure and representative tire temperature for each predetermined period for a plurality of tires 1 mounted on a vehicle 7, generates a graph showing the changes over time, and displays it on a display device. The tire monitoring device 30 accepts a user's input specifying the total display period for the graph of the representative tire pressure and representative temperature, and determines the predetermined period according to the total display period. By displaying the graph of the representative tire pressure and representative temperature, the tire monitoring device 30 presents the user with information for early detection of problems in the tires and surrounding areas.

[0015] Furthermore, the tire monitoring device 30 plots on the same graph the time-varying representative air pressure and the time-varying representative temperature for each of the plurality of tires 1 mounted on the vehicle 7. By plotting on the same graph the time-varying representative air pressure and the time-varying representative temperature for each of the plurality of tires 1, the tire monitoring device 30 presents to the user the differences in the changes in the representative air pressure and the representative temperature between the tires in a manner that makes it easy to visually recognize them.

[0016] The tire monitoring device 30 may transmit information on graphs showing the time-dependent changes in the representative air pressure and the representative temperature to the user terminal device 40, and the user terminal device 40 may display these graphs.

[0017] 2 is a block diagram showing the functional configuration of the tire monitoring device 30. The sensor 10 includes an air pressure sensor 11 and a temperature sensor 12 disposed in the tire 1. The air pressure sensor 11 measures the tire air pressure. The temperature sensor 12 measures the tire temperature. The air pressure sensor 11 and the temperature sensor 12 are disposed, for example, in the air valve of the tire 1. The temperature sensor 12 may be disposed directly in the tire 1 to accurately measure the temperature of the tire 1.

[0018] The vehicle measurement device 20 accumulates measurement data of tire pressure and tire temperature measured by the sensors 10 and transmits the data to the tire monitoring device 30 via the communication network 8. The vehicle measurement device 20 transmits the stored measurement data to the tire monitoring device 30, for example, every few minutes to every tens of minutes. The time interval at which the vehicle measurement device 20 transmits the measurement data to the tire monitoring device 30 is not limited to every few minutes to every tens of minutes. The measurement data transmitted from the vehicle measurement device 20 to the tire monitoring device 30 also includes information on the mounting position of each measured tire 1 on the axle arrangement.

[0019] The tire monitoring device 30 includes a communication unit 31, a memory unit 32, a display unit 33, an operation unit 34, and a processing unit 35. Each unit in the tire monitoring device 30 can be realized in hardware terms by an electronic processing circuit or mechanical parts made up of electronic elements such as a computer CPU, and in software terms by a computer program, etc. However, the functional blocks realized by the cooperation of these elements are depicted here. Therefore, it will be understood by those skilled in the art that these functional blocks can be realized in various forms by combining hardware and software.

[0020] The communication unit 31 is connected to the communication network 8 via wireless or wired communication and communicates with the vehicle measurement device 20. The storage unit 32 is a storage device configured, for example, by an SSD (Solid State Drive), a hard disk, a CD-ROM, a DVD, etc. The storage unit 32 stores vehicle management information 32a and sensor measurement data 32b.

[0021] The vehicle management information 32a is information relating to a plurality of vehicles 7 whose operation is managed by, for example, a transportation company, and includes the names of the vehicles 7, identification information of the vehicles 7 assigned to each vehicle, axle arrangement information, etc. The axle arrangement information includes information on the mounting positions of tires on the axle arrangement.

[0022] The sensor measurement data 32b is measurement data of tire pressure and tire temperature acquired from the vehicle measurement device 20 for each vehicle 7 included in the vehicle management information 32a. The sensor measurement data 32b includes information on the date and time when the tire pressure and tire temperature were measured.

[0023] The display unit 33 includes a display device such as a liquid crystal display, and displays a graph generated by a display processing unit 35d (described later) on the display device. The operation unit 34 is an operable input device such as a touch panel, a switch, a keyboard, or a mouse device. By operating the operation unit 34, the user can specify the total display period of the graph to be displayed on the display unit 33.

[0024] The processing unit 35 has an information acquisition unit 35a, a period setting unit 35b, a representative value calculation unit 35c, and a display processing unit 35d. The information acquisition unit 35a acquires the measurement data of the tire pressure and tire temperature transmitted by the vehicle measurement device 20 via the communication unit 31. The measurement data acquired by the information acquisition unit 35a is assumed to be associated with the identification information of the vehicle 7. The information acquisition unit 35a stores the acquired measurement data of the tire pressure and tire temperature in the memory unit 32.

[0025] The period setting unit 35b acquires an operation input from the user on the operation unit 34 to specify the total display period Ka when displaying the tire pressure and tire temperature graphs. The horizontal axis of the tire pressure and tire temperature graphs represents time. The total display period Ka of these graphs is, for example, one month, two weeks, one day, etc., and can be changed by the user. If the user does not specify a particular total display period Ka, a default value (for example, one month) is used. The total display period Ka specified by the user and the default value are not limited to these examples.

[0026] The period setting unit 35b sets the predetermined period Kp by dividing the entire display period Ka of the graph into 5 to 40 equal parts. For example, if the entire display period Ka of the graph is one month, the period setting unit 35b sets the predetermined period Kp to one day, and if the entire display period Ka of the graph is one day, the predetermined period Kp to one hour. As will be described later, in order to represent representative values ​​of tire air pressure and tire temperature calculated for each predetermined period Kp on the graph, it is preferable that the entire display period Ka be divided into approximately 5 to 40 equal parts, but this range is not limiting. The period setting unit 35b outputs the entire display period Ka of the graph and the set predetermined period Kp to the representative value calculation unit 35c and the display processing unit 35d.

[0027] The representative value calculation unit 35c reads out past tire pressure and tire temperature measurement data for the entire display period Ka from the current time point from the sensor measurement data 32b in the storage unit 32. The representative value calculation unit 35c calculates representative values ​​for the tire pressure and tire temperature for each predetermined period Kp.

[0028] The representative value calculation unit 35c calculates the minimum tire pressure value for each predetermined period Kp as a representative tire pressure Pr. The representative value calculation unit 35c calculates the maximum tire temperature value for each predetermined period Kp as a representative tire temperature Tr. The representative value calculation unit 35c outputs the representative tire pressure Pr and representative tire temperature Tr calculated for each predetermined period Kp to the display processing unit 35d.

[0029] For example, if the total display period Ka is one month and the predetermined period Kp is one day, the representative value calculation unit 35c calculates the minimum tire pressure for each day as the representative tire pressure Pr and the maximum tire temperature as the representative temperature Tr. The representative value calculation unit 35c may obtain the air pressure of the cooled tire 1 when the vehicle is not running for each predetermined period, for example, the air pressure of the tire 1 immediately after the engine of the vehicle 7 is started, and use this as the representative air pressure Pr. The air pressure of the cooled tire 1 is the air pressure of the tire 1 when the vehicle is stopped. Specific examples of the air pressure of the cooled tire 1 include the air pressure of the tire 1 when the engine is started and before running, and the air pressure of the tire after the vehicle has been stopped for a predetermined time.

[0030] The display processing unit 35d generates a graph based on the total display period Ka and the predetermined period Kp input from the period setting unit 35b, and the representative air pressure Pr and the representative temperature Tr for each predetermined period Kp input from the representative value calculation unit 35c. The display processing unit 35d generates a graph with the horizontal axis representing time corresponding to the total display period Ka and the vertical axis representing the representative air pressure Pr and the representative temperature Tr, respectively. The display processing unit 35d generates a graph showing the changes in the representative air pressure Pr and the representative temperature Tr over time, outputs the graph to the display unit 33, and displays the graphs side by side on the display device.

[0031] The display processing unit 35d arranges graphs showing the time transitions of the representative air pressure Pr and the representative temperature Tr one above the other on the screen of the display device. By displaying the graphs showing the time transitions of the representative air pressure Pr and the representative temperature Tr one above the other on the screen, it becomes easier to compare the transitions of the representative air pressure Pr and the representative temperature Tr of the tire 1.

[0032] The display processing unit 35d may transmit the generated graph to the user terminal device 40 via the communication unit 31, and the graph showing the time changes of the representative air pressure Pr and the representative temperature Tr may be displayed on the user terminal device 40. In this case, the user may specify the total display period Ka through an operation unit (not shown) of the user terminal device 40, and the period setting unit 35b may set the predetermined period Kp based on the information on the total display period Ka transmitted from the user terminal device 40. The user terminal device 40 is an information processing device such as a smartphone or a personal computer.

[0033] Next, the operation of the tire monitoring system 100 will be described. Fig. 3 is a flowchart showing the procedure for graph display processing by the tire monitoring device 30. An example of displaying a graph corresponding to a vehicle pre-selected by the user will be described below. The information acquisition unit 35a of the tire monitoring device 30 acquires measurement data of tire pressure and tire temperature from the vehicle measurement device 20 (S1). The information acquisition unit 35a outputs the acquired measurement data of tire pressure and tire temperature to the storage unit 32 and stores it as sensor measurement data 32b.

[0034] The period setting unit 35b acquires the total display period Ka of the graph specified by the user through an operation input (S2). If the user does not specify the total display period Ka of the graph in step S2, the period setting unit 35b may set the total display period to a default value. The period setting unit 35b sets a predetermined period Kp according to the total display period Ka (S3). As described above, the period setting unit 35b may set the predetermined period Kp by dividing the total display period Ka by, for example, 5 to 40.

[0035] The representative value calculation unit 35c reads past tire pressure and tire temperature measurement data for the entire display period Ka from the current time point from the sensor measurement data 32b in the storage unit 32, and calculates a representative tire pressure Pr and a representative temperature Tr for each predetermined period Kp (S4). The representative value calculation unit 35c calculates the minimum tire pressure as the representative tire pressure Pr and the maximum tire temperature as the representative temperature Tr for each predetermined period Kp.

[0036] The display processing unit 35d generates graphs showing the time transition of the representative air pressure Pr and the representative temperature Tr, outputs the graphs to the display unit 33, and displays the graphs side by side on the display device (S5), and the process ends.

[0037] Fig. 4 is a graph showing an example of time-dependent changes in the representative air pressure Pr of tire 1. In Fig. 4, the horizontal axis represents time and the vertical axis represents the representative air pressure Pr. In Fig. 4, the total display period Ka of the graph is nine days from September 22 to September 30, and the predetermined period Kp is one day.

[0038] The example shown in Figure 4 is for a truck vehicle with one axle at the front and one at the rear of the vehicle, with two tires A11 and A12 on the front axle and four tires A21, A22, A23, and A24 on the rear axle. For simplicity, Figure 4 shows the graphs of the representative air pressures Pr for tires A11, A21, and A24. The graphs of the representative air pressures Pr for the other tires A12, A22, and A23 largely overlap the graph for tires A11 and A21.

[0039] In Figure 4, the representative air pressure Pr of tire A24 shows a tendency to decrease more than the other tires after September 24, making it easy to recognize that some kind of problem is occurring with the tire. In the example shown in Figure 4, the lower limit Ps of the tire air pressure setting range is 500 kPa, and on September 29, the representative air pressure Pr of tire A24 fell below the lower limit Ps.

[0040] In the example shown in FIG. 4, tire pressure was increased for all tires, including tire A24, during maintenance performed on September 30. The graph shows a gradual decrease in tire pressure for tire A24, suggesting the possibility of a slow leak. A slow leak in tire 1 occurs when air leaks more rapidly than normal natural pressure reduction, and can be caused by misalignment between the tire and wheel during assembly, as well as deterioration or installation problems with the rubber gasket or valve seal. By displaying a graph showing the time evolution of the representative air pressure Pr of tire 1 mounted on vehicle 7, tire monitoring device 30 can present useful information to the user to quickly recognize the occurrence of a slow leak in the tire.

[0041] Fig. 5 is a graph showing another example of the change over time in the representative air pressure Pr of the tire 1. In Fig. 5, the horizontal axis represents time and the vertical axis represents the representative air pressure Pr. In Fig. 5, the total display period Ka of the graph is one day, the predetermined period Kp is one hour, and the change over time in the representative air pressure Pr from 7:00 to 5:00 the next day is shown.

[0042] The example shown in Figure 5 relates to a truck vehicle with one axle at the front of the vehicle and two axles at the rear. Four tires B11, B12, B21, and B22 are arranged on the front axle. Four tires B31, B32, B33, and B34 are arranged on one rear axle, and four tires B41, B42, B43, and B44 are arranged on the other rear axle. For simplicity of the graph, Figure 5 shows graphs of representative air pressures Pr for tires B11, B31, and B41. The graphs of representative air pressures Pr for the other tires generally overlap the graphs for tires B11 and B31.

[0043] In Figure 5, the representative air pressure Pr of tire B41 tends to decrease more than the other tires after 9:00, making it easy to recognize that some kind of tire malfunction is occurring. In the example shown in Figure 5, the lower limit of the tire air pressure setting range is 800 kPa, and at 18:00, the representative air pressure Pr of tire B41 falls below the lower limit (= 800 kPa).

[0044] 5, the graph shows a tendency for the representative air pressure Pr of tire B41 to drop sharply, which suggests the possibility of a tire puncture. By displaying a graph showing the time evolution of the representative air pressure Pr of tire 1 mounted on vehicle 7, tire monitoring device 30 can present useful information to the user to quickly recognize that a tire puncture has occurred.

[0045] The information acquisition unit 35a of the tire monitoring device 30 acquires measurement data from the air pressure sensor 11 provided on the tire 1 mounted on the vehicle 7. The representative value calculation unit 35c calculates a representative air pressure Pr for each predetermined period Kp based on the measurement data acquired by the information acquisition unit 35a. The display processing unit 35d generates a graph showing the time evolution of the representative air pressure Pr calculated by the representative value calculation unit 35c and displays it on the display device. This allows the tire monitoring device 30 to present useful information to the user to quickly recognize any problems with the tire 1.

[0046] The representative value calculation unit 35c calculates the minimum tire pressure value during the predetermined period Kp as the representative tire pressure Pr. This allows the tire monitoring device 30 to unify the minimum tire pressure value during the predetermined period Kp as the representative tire pressure Pr, and to present conditions such as slow leaks and punctures to the user in an easily understandable manner.

[0047] The representative value calculation unit 35c may set the tire pressure during cooling as the representative tire pressure Pr. In this way, when the predetermined period Kp is set to one day, for example, the tire monitoring device 30 can present useful information to the user to promptly recognize a problem using the tire pressure during cooling, such as immediately after starting the engine of the vehicle 7, as a reference.

[0048] Based on a user's operation input specifying the total display period Ka of the graph, the period setting unit 35b sets the predetermined period Kp according to the total display period Ka. This allows the tire monitoring device 30 to calculate the representative air pressure Pr for the predetermined period Kp according to the length of the total display period Ka using the representative value calculation unit 35c.

[0049] The display processing unit 35d displays the plurality of tires 1 mounted on the vehicle 7 on the same graph. This allows the tire monitoring device 30 to present a graph that makes it easy to compare the representative air pressures Pr of the plurality of tires 1 mounted on the vehicle 7.

[0050] FIG. 6 is a schematic diagram showing an example of displaying graphs of the time evolution of the representative air pressure Pr and the representative temperature Tr side by side. In FIG. 6, the horizontal axis represents time, and the vertical axis represents the representative air pressure Pr and the representative temperature Tr. In FIG. 6, the total display period Ka of the graph is 11 days from July 22 to August 1, and the predetermined period Kp is set to 1 day. FIG. 6 shows the display images on the display devices of the tire monitoring device 30 and the user terminal device 40. If the horizontal axis is set to the horizontal direction and the vertical axis is set to the up-down direction, FIG. 6 shows an example of displaying graphs of the time evolution of the representative air pressure Pr and the representative temperature Tr side by side.

[0051] The example shown in Figure 6 is for a truck vehicle with one axle at the front and two axles at the rear. Four tires C11, C12, C21, and C22 are arranged on the front axle. Four tires C31, C32, C33, and C34 are arranged on one rear axle, and four tires C41, C42, C43, and C44 are arranged on the other rear axle.

[0052] For the sake of simplicity, the graph of representative air pressure Pr shown in the upper part of Figure 6 shows the graphs of representative air pressure Pr for tires C11, C12, and C21. The graphs of representative air pressure Pr for the other tires generally follow the same trends as the graphs for tires C11 and C12. For the sake of simplicity, the graph of representative temperature Tr shown in the lower part of Figure 6 shows the graphs of representative temperature Tr for tires C11, C12, C21, and C31. The graphs of representative temperature Tr for the other tires generally follow the same trends as the graphs for tires C12 and C31.

[0053] The representative temperature Tr of tire C11 exceeded the high temperature usage limit value Ts (=90°C) on July 30. The representative temperature Tr of tire C21 also exceeded the usage limit value Ts on July 30 and July 31. From the graph showing the change in representative temperature Tr over time, it is possible that some kind of problem has occurred in the tires or around the tires, as the representative temperatures Tr of tires C11 and C21 exceeded the usage limit value Ts.

[0054] The representative air pressure Pr of tire C11 did not show any significant change from July 22 to August 1. The representative air pressure Pr of tire C21 rose slightly on July 29, not indicating a drop in air pressure. Generally, when tire air pressure drops significantly, the tire's rigidity decreases, increasing mechanical vibrations inside the tire while the vehicle is in motion, which is thought to cause the tire temperature to rise. Because no significant drop in the representative air pressure Pr of tires C11 and C21 was observed, it can be concluded that the situation in which the representative temperature Tr of tires C11 and C21 exceeded the service limit value Ts was likely due to influences from the surrounding area of ​​the tire, rather than being caused by the tire itself.

[0055] Around the tire are mechanical parts on the vehicle, such as bearings and brake parts located in the hub. When friction increases in the mechanical parts on the vehicle around the tire, heat generated can be transferred to the tire, causing the tire to become hot. In the example shown in Figure 6, it was found that the heat generated in the brake parts near tires C11 and C21 actually caused the tire temperature to rise.

[0056] The information acquisition unit 35a of the tire monitoring device 30 acquires measurement data from air pressure sensors and temperature sensors provided on the tires 1 mounted on the vehicle 7. The representative value calculation unit 35c calculates a representative air pressure Pr and a representative temperature Tr for each predetermined period Kp based on the measurement data acquired by the information acquisition unit 35a. The display processing unit 35d generates a graph showing the time evolution of the representative air pressure Pr calculated by the representative value calculation unit 35c and a graph showing the time evolution of the representative temperature Tr, and displays them side by side on the display device. This allows the tire monitoring device 30 to present useful information to the user to quickly recognize any problems in the tires 1 or around the tires.

[0057] The representative value calculation unit 35c calculates the minimum tire pressure value within the predetermined period Kp as the representative tire pressure Pr. As a result, the tire monitoring device 30 unifies the minimum tire pressure value within the predetermined period Kp as the representative tire pressure Pr, and can present useful information to the user to promptly recognize problems in the tire 1 or its surroundings in relation to the tire temperature, in addition to problems such as slow leaks and punctures.

[0058] The representative value calculation unit 35c calculates the maximum tire temperature within the predetermined period Kp as the representative temperature Tr. This allows the tire monitoring device 30 to standardize the maximum tire temperature within the predetermined period Kp as the representative temperature Tr, and to present useful information to the user to quickly recognize any problems in or around the tire 1.

[0059] The period setting unit 35b sets the predetermined period Kp according to the total display period Ka based on a user's operation input specifying the total display period Ka of the graph. This allows the tire monitoring device 30 to calculate the representative air pressure Pr and the representative temperature Tr for the predetermined period Kp according to the length of the total display period Ka using the representative value calculation unit 35c.

[0060] The display processing unit 35d displays the plurality of tires 1 mounted on the vehicle 7 on the same graph. This allows the tire monitoring device 30 to present a graph that makes it easy to compare the representative air pressures Pr and representative temperatures Tr of the plurality of tires 1 mounted on the vehicle 7.

[0061] (Embodiment 2) 7 is a block diagram showing the functional configuration of a tire monitoring device 30 according to embodiment 2. The tire monitoring device 30 according to embodiment 2 includes a defect determination unit 35e and a notification processing unit 35f in addition to the components of the tire monitoring device 30 according to embodiment 1. The tire monitoring device 30 according to embodiment 2 also stores determination result information 32c in the storage unit 32.

[0062] The malfunction determination unit 35e determines whether or not there is a possibility of a malfunction occurring in the tire or the vicinity of the tire. The malfunction determination may include, for example, the following four types of malfunction: First, the malfunction determination unit 35e determines whether or not the representative temperature Tr of the tire 1 exceeds the service limit value Ts.

[0063] If the representative temperature Tr exceeds the service limit value Ts, the malfunction determination unit 35e stores information on the determination result that the malfunction is a high temperature abnormality as determination result information 32c in the storage unit 32, and outputs the determination result information to the notification processing unit 35f. The determination result information includes the date and time when the high temperature abnormality occurred, identification information for the vehicle 7, and information on the tire mounting position on the axle arrangement, and this also applies to determinations other than a high temperature abnormality. Note that the determination result information 32c can be used after the malfunction has occurred to reconfirm and tally the status of the malfunction, perform another notification process, and so on.

[0064] Second, the malfunction determination unit 35e determines whether the representative air pressure Pr of the tire 1 is smaller than the lower limit value Ps of the setting range of the tire air pressure. The malfunction determination unit 35e may set a threshold value Pss that is smaller than the lower limit value Ps of the setting range of the tire air pressure, and determine whether the representative air pressure Pr of the tire 1 is smaller than the threshold value Pss.

[0065] If the representative air pressure Pr is smaller than the lower limit value Ps or the threshold value Pss, the malfunction judgment unit 35e stores the judgment result information that there is an air pressure drop abnormality in the memory unit 32 as judgment result information 32c, and outputs the judgment result information to the notification processing unit 35f.

[0066] Third, the malfunction determination unit 35e calculates the rate of change Pc of the representative air pressure Pr of the tire 1 over time and compares it with a predetermined first threshold value ΔP1 and a predetermined second threshold value ΔP2. The malfunction determination unit 35e calculates the representative air pressure Pr for each day, for example, and calculates the difference between the value for each day and the value for the previous day to determine the rate of change Pc. The malfunction determination unit 35e also calculates the representative air pressure Pr for each hour, for example, and calculates the difference between the value for each hour and the value for the previous hour to determine the rate of change Pc.

[0067] Considering that tire defects may occur when tire air pressure decreases, the change rate Pc is calculated as an absolute value when tire air pressure changes to the negative side. The defect determination unit 35e sets the second threshold value ΔP2 to a value greater than the first threshold value ΔP1, and determines that a slow leak defect may have occurred if the change rate Pc of the representative air pressure Pr is greater than the first threshold value ΔP1 and less than the second threshold value ΔP2. The defect determination unit 35e determines that a puncture defect may have occurred if the change rate Pc of the representative air pressure Pr is greater than the second threshold value ΔP2.

[0068] The malfunction determination unit 35e sets the first threshold value ΔP1 and the second threshold value ΔP2 based on the cases related to slow leaks and punctures described above with reference to Figures 4 and 5, and on detailed design analysis of the tire. The malfunction determination unit 35e stores information on the determination result that there is a slow leak or a puncture as determination result information 32c in the storage unit 32, and outputs the information on the determination result to the notification processing unit 35f.

[0069] Fourth, the malfunction determination unit 35e determines whether a decrease in the representative air pressure Pr has occurred when the representative temperature Tr of the tire 1 exceeds the service limit value Ts (=90°C). It determines whether the decrease in the representative air pressure Pr is greater than a predetermined threshold. This is to determine whether the cause of the high temperature abnormality in the tire, as explained above with reference to FIG. 6, is the tire itself or the vehicle side around the tire.

[0070] The malfunction determination unit 35e determines that there is a possibility that a malfunction has occurred on the vehicle side around the tire when the representative temperature Tr of the tire 1 exceeds the service limit value Ts and the amount of decrease in the representative air pressure Pr is smaller than a predetermined threshold. The malfunction determination unit 35e determines that there is a possibility that a malfunction has occurred in the tire itself when the representative temperature Tr of the tire 1 exceeds the service limit value Ts and the amount of decrease in the representative air pressure Pr is larger than a predetermined threshold. The malfunction determination unit 35e stores information on the determination result that there is a slow leak or a puncture as determination result information 32c in the memory unit 32, and outputs the information on the determination result to the notification processing unit 35f.

[0071] Furthermore, even when the outside air temperature is low, such as in winter in Japan, and the tires do not become abnormally high in temperature, the malfunction determination unit 35e may determine that the tire temperature has risen to a high temperature and that there is a possibility that a malfunction has occurred in the tire itself or in the vehicle. For this malfunction determination, for example, the method disclosed in Japanese Patent Application No. 2024-061938 may be used.

[0072] The notification processing unit 35f displays information about the determination result by the defect determination unit 35e on the display unit 33 and notifies the user. The notification processing unit 35f may also generate an email including the information about the determination result and send it to an email address owned by the user. The user can receive the email sent by the notification processing unit 35f using an email sending / receiving application or the like in the tire monitoring device 30 and the user terminal device 40, and can learn the information about the determination result by the defect determination unit 35e.

[0073] The tire monitoring device 30 determines whether or not there is a possibility of a malfunction by the malfunction determination unit 35e, and if it determines that there is a possibility of a malfunction, notifies the determination result to the outside by the notification processing unit 35f. In this way, the tire monitoring device 30 can make the user or the like aware of the determination result regarding the occurrence of a malfunction in the tire 1 mounted on the vehicle 7.

[0074] When generating a graph showing the time evolution of the representative air pressure Pr and the representative temperature Tr, the display processing unit 35d may refer to the judgment result information 32c and highlight the time point at which a malfunction occurred on the graph. FIG. 8 is a graph showing the time evolution of the representative temperature with the time point at which a malfunction occurred highlighted. In FIG. 8, the time point at which a high temperature abnormality occurred in the tire 1 is highlighted with a star-shaped symbol, and a graphic indicating an alarm such as an "!" symbol and a note indicating that an alert is being issued are placed near the star-shaped symbol in the display image.

[0075] When the defect determination unit 35e determines that a defect may have occurred, the tire monitoring device 30 causes the display processing unit 35d to highlight the time point at which the defect occurred on the graph. This allows the tire monitoring device 30 to clearly present the state in which the defect has occurred, and prevents the user from overlooking a defect in or around the tire.

[0076] (Variation) In each of the above-described embodiments, the transportation company is not limited to a company that operates and manages transportation trucks, but also includes, for example, a taxi company, etc. Furthermore, the vehicle 7 is not limited to a truck vehicle or a taxi vehicle, but also includes a rental vehicle from a rental company, a shared vehicle provided by a vehicle sharing company, a private car purchased by an ordinary household, etc.

[0077] The present invention has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications and changes are possible within the scope of the claims of the present invention, and that such modifications and changes also fall within the scope of the claims of the present invention. Therefore, the descriptions and drawings in this specification should be treated as illustrative rather than restrictive.

[0078] When the technical ideas embodied in the above-described embodiments and modified examples are generalized, it can be said that the technical ideas described in the following items are included.

[0079] The first item is a tire monitoring device that includes an information acquisition unit that acquires measurement data from an air pressure sensor installed in a tire mounted on a vehicle, a representative value calculation unit that calculates a representative air pressure at predetermined intervals based on the measurement data acquired by the information acquisition unit, and a display processing unit that generates a graph showing the time-varying change in the representative air pressure calculated by the representative value calculation unit and displays it on a display device.

[0080] A second item is the tire monitoring device according to the first item, wherein the representative value calculation unit calculates a minimum tire pressure value in the predetermined period as the representative tire pressure.

[0081] A third item is the tire monitoring device according to the first item, wherein the representative value calculation unit sets the tire pressure during cooling as the representative pressure.

[0082] A fourth item is a tire monitoring device described in any one of the first to third items, further comprising a period setting unit that sets the specified period according to the total display period based on a user's operational input that specifies the total display period of the graph.

[0083] A fifth item is the tire monitoring device according to any one of the first to fourth items, wherein the display processing unit displays a plurality of tires mounted on a vehicle on the same graph.

[0084] A sixth item is a tire monitoring device according to any one of the first to fifth items, wherein the information acquisition unit acquires measurement data from a temperature sensor provided in the tire, the representative value calculation unit calculates a representative temperature for each predetermined period based on the measurement data acquired by the information acquisition unit, and the display processing unit displays a graph showing the time-dependent change in the representative temperature calculated by the representative value calculation unit alongside a graph showing the time-dependent change in the representative air pressure.

[0085] The seventh item is a tire monitoring method including an information acquisition step of acquiring measurement data from an air pressure sensor provided on a tire mounted on a vehicle, a representative value calculation step of calculating a representative air pressure at predetermined intervals based on the measurement data acquired by the information acquisition step, and a display processing step of generating a graph showing the time-varying change in the representative air pressure calculated by the representative value calculation step and displaying the graph on a display device. [Explanation of symbols]

[0086] 1 tire, 7 vehicle, 11 air pressure sensor, 12 temperature sensor, 30 tire monitoring device, 35a information acquisition unit, 35b period setting unit, 35c Representative value calculation unit, 35d Display processing unit.

Claims

1. an information acquisition unit that acquires measurement data from air pressure sensors provided in tires mounted on a vehicle; a representative value calculation unit that calculates a representative air pressure for each predetermined period based on the measurement data acquired by the information acquisition unit; a display processing unit that generates a graph showing the time course of the representative air pressure calculated by the representative value calculation unit and displays the graph on a display device; A tire monitoring device comprising:

2. The tire monitoring device according to claim 1 , wherein the representative value calculation unit calculates the minimum tire pressure value in the predetermined period as the representative tire pressure.

3. The tire monitoring device according to claim 1 , wherein the representative value calculation unit sets the tire pressure during cooling as the representative pressure.

4. a period setting unit that sets the predetermined period in accordance with a total display period of the graph based on a user's operation input that specifies the total display period of the graph; The tire monitoring device of claim 1 further comprising:

5. The tire monitoring device according to claim 1 , wherein the display processing unit displays a plurality of tires mounted on a vehicle on the same graph.

6. the information acquisition unit acquires measurement data from a temperature sensor provided in a tire, the representative value calculation unit calculates a representative temperature for each predetermined period based on the measurement data acquired by the information acquisition unit; The tire monitoring device according to claim 1 , wherein the display processing unit displays a graph showing the time course of the representative temperature calculated by the representative value calculation unit alongside a graph showing the time course of the representative air pressure.

7. an information acquisition step of acquiring measurement data from an air pressure sensor provided in a tire mounted on the vehicle; a representative value calculation step of calculating a representative air pressure for each predetermined period based on the measurement data acquired in the information acquisition step; a display processing step of generating a graph showing the time course of the representative air pressure calculated in the representative value calculation step and displaying the graph on a display device; A tire monitoring method comprising:

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