Tire air pressure monitoring system, tire air pressure monitoring program, and tire air pressure monitoring method

Abstract

A tire air pressure monitoring system repeatedly acquires an internal pressure value of a pneumatic tire, and starts a timer in a case where the internal pressure value becomes lower than a warning threshold. The tire air pressure monitoring system stops output of warning information corresponding to the warning threshold even if the internal pressure value becomes lower than the warning threshold again until the timer expires. The tire air pressure monitoring system newly starts the timer in a case where the internal pressure value becomes lower than the warning threshold or a danger threshold and then rises to be higher than the warning threshold during a period until the timer expires.

Description

Technical Field

[0001] This disclosure relates to a tire pressure monitoring system, a tire pressure monitoring program, and a tire pressure monitoring method for monitoring the air pressure of tires installed on a vehicle. Background Technology

[0002] Previously, tire pressure monitoring systems were widely used to monitor the air pressure (internal pressure) of pneumatic tires (hereinafter referred to as tires) installed on vehicles.

[0003] The internal pressure value of a pneumatic tire measured by a sensor may vary depending on the temperature of the air chamber inside the pneumatic tire mounted on the rim and the measurement error of the sensor. Therefore, a technique is known to use a counter for the number of measurements to control the timing of the alarm for a drop in internal pressure (Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 7-186643 Summary of the Invention

[0007] However, when the internal pressure value fluctuates around the threshold that serves as the basis for the alarm, the alarms are generated and stopped frequently, placing a significant load on the tire pressure monitoring system and raising concerns that users may find it annoying.

[0008] Therefore, the following disclosure is made in view of the following situation, and its purpose is to provide a tire pressure monitoring system, tire pressure monitoring method and tire pressure monitoring procedure that can prevent the frequent generation and cessation of alarms and can output an alarm for internal pressure drop at the appropriate time.

[0009] One aspect of this disclosure is a tire pressure monitoring system (tire pressure monitoring system 10), comprising: an acquisition unit (tire data acquisition unit 110) that repeatedly acquires the internal pressure value of an inflatable tire (tire 30); a timer control unit (timer control unit 130) that starts a timer when the internal pressure value falls below a warning threshold; and an alarm unit (alarm unit 150) that outputs a warning message until the timer expires when the internal pressure value falls below the warning threshold, and outputs a danger message until the timer expires when the internal pressure value falls below a danger threshold lower than the warning threshold, wherein the timer control unit restarts the timer again when the internal pressure value rises above the warning threshold after falling below the warning threshold or the danger threshold during the period until the timer expires.

[0010] One aspect of this disclosure is a tire pressure monitoring program that causes a computer to perform the following processes: an acquisition process that repeatedly acquires the internal pressure value of an inflated tire; a timer control process that starts a timer when the internal pressure value falls below a warning threshold; and an alarm process that outputs a warning message until the timer expires when the internal pressure value falls below the warning threshold, and outputs a danger message until the timer expires when the internal pressure value falls below a danger threshold lower than the warning threshold, wherein, in the timer control process, during the period until the timer expires, if the internal pressure value rises above the warning threshold after falling below the warning threshold or the danger threshold, the timer is restarted.

[0011] One aspect of this disclosure is a tire pressure monitoring method, comprising the following steps: repeatedly acquiring the internal pressure value of an inflatable tire; starting a timer when the internal pressure value falls below a warning threshold; and outputting a warning message until the timer expires when the internal pressure value falls below the warning threshold, and outputting a danger message until the timer expires when the internal pressure value falls below a danger threshold lower than the warning threshold, wherein, in the step of starting the timer, during the period until the timer expires, if the internal pressure value rises above the warning threshold after falling below the warning threshold or the danger threshold, the timer is restarted. Attached Figure Description

[0012] Figure 1 This is a general structural diagram of the tire pressure monitoring system 10.

[0013] Figure 2 This is a top-view summary of vehicle 20.

[0014] Figure 3 This is a functional block structure diagram of sensor unit 40.

[0015] Figure 4 This is a functional block structure diagram of the tire status monitoring server 100.

[0016] Figure 5 This is a diagram showing the outline of the action flow of the alarm output of the internal pressure value by the tire condition monitoring server 100.

[0017] Figure 6 This is a diagram showing an example of the alarm output action based on previous internal pressure values.

[0018] Figure 7 This is a diagram illustrating an example of the alarm output of the internal pressure value involved in this embodiment. Detailed Implementation

[0019] The embodiments will now be described based on the accompanying drawings. Furthermore, descriptions of identical or similar functions and structures will be omitted where appropriate.

[0020] (1) Overall structure of the tire pressure monitoring system

[0021] Figure 1 This is a schematic diagram of the overall structure of the tire pressure monitoring system 10 according to this embodiment. Figure 1 As shown, the tire pressure monitoring system 10 provides monitoring services for a fleet of multiple vehicles 20, including trucks. The tire pressure monitoring system 10 essentially monitors the status of each vehicle 20 from a fixed location, such as a yard, where the multiple vehicles 20 are parked.

[0022] In this embodiment, the tire pressure monitoring system 10 monitors the state of the vehicle 20, specifically the state of the inflated tires installed on the vehicle 20, which are specifically tires 30 (in...). Figure 1 Not shown in the image, please refer to the diagram. Figure 2 ).

[0023] The tire pressure monitoring system 10 includes a tire condition monitoring server 100, which monitors the condition of multiple tires 30 installed on the vehicle 20 using multiple sensors corresponding to each of the multiple tires 30 in a location far from the vehicle 20, such as the user's site.

[0024] Regarding vehicle 20, in this embodiment, it refers to a vehicle such as a truck used in a business or enterprise. Therefore, vehicle 20 may be, for example, a bus or taxi, in addition to a truck. Multiple vehicles 20 are used by users 80 such as businesses. However, users 80 do not necessarily have to be businesses, but may be groups or individuals that do not aim to make a profit.

[0025] The tire condition monitoring server 100 is connected to the communication network 70. The communication network 70 is a communication network that uses wired or wireless communication methods, and may also include the Internet.

[0026] In addition, the communication network 70 includes a wireless access network known as a so-called Low Power Wide Area Network (LPWA or LPWAN, hereinafter appropriately abbreviated as LPWA).

[0027] LPWA is a wireless access method that provides a coverage range that short-range wireless methods (ranging from tens of meters) such as Bluetooth cannot achieve. Its characteristics include low power consumption, low bit rate, and wide coverage.

[0028] Examples of services that utilize LPWA include Sigfox (registered trademark), LoRa (registered trademark), and Wi-Fi HaLow. In this embodiment, the tire pressure monitoring system 10 is based on the use of a service employing LPWA. However, LPWA can also be referred to by other names, as long as it is a wireless communication method that has a wider coverage range than short-range wireless methods such as Bluetooth (registered trademark) and achieves lower power consumption than mobile communication methods such as 4G / LTE (Long Term Evolution).

[0029] Base station 60 is an LPWA-compliant wireless base station and is a component of the low-power wide area network included in communication network 70. To ensure the range of communication via the low-power wide area network, multiple base stations 60 are geographically distributed.

[0030] (2) Vehicle structure

[0031] Figure 2 This is a top-view schematic view of vehicle 20. As described above, in this embodiment, vehicle 20 is assumed to be a truck.

[0032] like Figure 2 As shown, vehicle 20 has a front axle 21 and a rear axle 22. The front axle 21 is the steering axle and is located at the front of vehicle 20. The rear axle 22 is the drive axle and is located at the rear of vehicle 20, that is, on the loading compartment (loading platform) side. The rear axle 22 is a dual-tire axle, with two tires 30 mounted on each side.

[0033] A total of six tires 30 are installed in a vehicle 20 having this axle structure. A sensor unit 40 is installed for each tire 30. Specifically, the sensor unit 40 is mounted on the inner surface of the rim (not shown) where the tire 30 is mounted. Furthermore, the mounting location of the sensor unit 40 does not necessarily have to be the inner surface of the rim (rim groove portion), but can also be the inner surface of the tire 30, or even the base side of the air valve on the rim.

[0034] The sensor unit 40 senses the state of the tire 30. Specifically, the sensor unit 40 measures the air pressure (internal pressure) and temperature of the tire 30 mounted on the rim. In addition to measuring internal pressure and temperature, the sensor unit 40 can also measure, for example, strain.

[0035] In addition, the sensor unit 40 has wireless communication capabilities, specifically LPWA-compliant wireless communication capabilities, and is able to perform wireless communication with the base station 60.

[0036] (3) Functional block structure of sensor unit and tire pressure monitoring system

[0037] Next, the functional block structure of the sensor unit 40 and the tire condition monitoring server 100 described above will be explained.

[0038] (3.1) Sensor Unit 40

[0039] Figure 3 This is a functional block structure diagram of sensor unit 40. (Example) Figure 3 As shown, the sensor unit 40 includes a temperature sensor 41, a pressure sensor 43, a sensor ID setting unit 45, a wireless communication unit 47, and a battery 49.

[0040] Temperature sensor 41 measures the temperature inside the air chamber of tire 30, which is mounted on the rim.

[0041] As a temperature sensor 41, a semiconductor type can be used, for example.

[0042] Pressure sensor 43 measures the pressure (internal pressure) inside the air chamber of tire 30. As pressure sensor 43, for example, an electrostatic capacitive type can be used.

[0043] Accelerometer 44 detects the acceleration of tire 30 in a specified direction. In this embodiment, accelerometer 44 can detect the acceleration of tire 30 in the radial direction, specifically centrifugal acceleration (or centrifugal force). Furthermore, in addition to the radial direction, accelerometer 44 can also detect acceleration in the tire width direction, etc. As accelerometer 44, a general-purpose accelerometer such as a triaxial accelerometer can be used.

[0044] The sensor ID setting unit 45 sets the sensor ID (sensor identification information) used to identify the sensor unit 40. Specifically, the sensor ID setting unit 45 stores the identification information of the sensor unit 40 and provides the stored identification information to the wireless communication unit 47. Additionally, it may include more information (such as tire type). The sensor identification information is multiplexed in the wireless signal transmitted from the wireless communication unit 47.

[0045] The wireless communication unit 47 has a wireless communication function that complies with LPWA. Specifically, the wireless communication unit 47 transmits a wireless signal (radio wave) to the base station 60 by multiplexing the data representing the measured temperature output from the temperature sensor 41 and the data representing the measured pressure (internal pressure) output from the pressure sensor 43.

[0046] Alternatively, it can be configured that during the period when the sensor unit 40 detects acceleration, that is, during the period when the tire 30 rotates, the temperature sensor 41 and the pressure sensor 43 do not measure temperature and internal pressure.

[0047] The battery 49 supplies the power required by the various functional blocks constituting the sensor unit 40. Specifically, the type of battery 49 is not particularly limited, but it is preferable to be a primary battery or the like that can continuously drive the sensor unit 40 for a long time (e.g., more than a year).

[0048] (3.2) Tire status monitoring server 100

[0049] Figure 4 This is a functional block structure diagram of the tire condition monitoring server 100. (Example) Figure 4 As shown, the tire status monitoring server 100 includes a tire data acquisition unit 110, a timer control unit 130, and an alarm unit 150.

[0050] These functional blocks are implemented by executing computer programs (software) on hardware such as server computers.

[0051] Specifically, the tire condition monitoring server 100 includes a processor, memory, input devices, a display, and external interfaces as hardware components. Furthermore, the computer program (software) can be provided via the communication network 70 or recorded on computer-readable recording media such as optical discs, hard disk drives, or flash memory.

[0052] Tire data acquisition unit 110 receives data from sensor unit 40 (reference) Figure 2 , Figure 3 The tire data acquisition unit 110 acquires tire data representing the state of the tire 30. Specifically, the tire data acquisition unit 110 directly acquires tire data from multiple sensors, such as temperature sensor 41 and pressure sensor 43, which are configured to correspond to multiple tires 30 and are installed on the tire 30 (specifically the rim, the same below), via wireless communication.

[0053] The tire data includes at least the internal pressure data measured by the pressure sensor 43. The internal pressure data only needs to be data that can determine the internal pressure value of the tire 30. It can be either a direct display of the internal pressure value or an index with fewer bits compared to a direct display.

[0054] Additionally, the tire data may also include temperature data measured by temperature sensor 41. Furthermore, if sensor unit 40 is equipped with other sensors (such as an acceleration sensor), the data measured by those sensors may also be included in the tire data.

[0055] The tire data acquisition unit 110 repeatedly acquires tire data from the sensor unit 40 via the base station 60 and the communication network 70. In this embodiment, the tire data acquisition unit 110 is configured to repeatedly acquire the internal pressure value of an inflated tire.

[0056] In this embodiment, the tire data acquisition unit 110 acquires tire data via low-power wide-area network (LPWA) based wireless communication. That is, instead of acquiring tire data from the sensor unit 40 via the vehicle 20 using short-range wireless communication, the tire data acquisition unit 110 directly acquires tire data from the sensor unit 40 via wireless communication using LPWA.

[0057] The timing (repetition period) for acquiring tire data is not specifically limited, but it is generally set to a interval of 1 to 10 minutes. Furthermore, considering the characteristics of LPWA (Laptop-Based Vehicle Analysis), the acquisition timing (repetition period) can be even longer.

[0058] The timer control unit 130 controls a timer for determining the timing of outputting information indicating abnormal tire data. Specifically, the timer control unit 130 can control a timer for determining the timing of outputting warning and hazard information.

[0059] Warning messages can also be referred to as alerts. A warning can be interpreted as a notification to user 80 (and / or the driver of vehicle 20, hereinafter the same) to notice a drop in internal pressure. Warnings are used to alert user 80 to a drop in internal pressure and can also be positioned as alarms that do not require immediate action.

[0060] Dangerous information can also be referred to as "Critical". Danger can be interpreted as a request for the user to take emergency measures, such as stopping the vehicle and checking the condition of the tires.

[0061] Alternatively, warning messages can be mapped to a threshold value of internal pressure (called the warning threshold), and danger messages can be mapped to a threshold value of internal pressure that is lower than the warning threshold (called the danger threshold).

[0062] For example, a warning threshold can be set at a 5% to 10% drop in recommended tire pressure, and a danger threshold at approximately a 20% drop in recommended tire pressure. Recommended tire pressure can be either the pressure specified by the vehicle manufacturer or the pressure corresponding to maximum load capacity (also known as normal tire pressure) in the JATMA (Japan Automobile Tire Association) Yearbook. Furthermore, ETRTO is used in Europe, TRA in the United States, and tire standards from other countries are also supported.

[0063] The timer control unit 130 starts the timer when the internal pressure value falls below a warning threshold. Specifically, the timer control unit 130 can start the timer when the internal pressure value of the tire data acquired by the tire data acquisition unit 110 falls below a warning threshold.

[0064] On the other hand, the timer control unit 130 can restart the timer if the internal pressure value acquired by the tire data acquisition unit 110 rises above the warning threshold after it has fallen below the warning threshold or danger threshold. Alternatively, the timer control unit 130 may not restart the timer even if the internal pressure value falls below the warning threshold or danger threshold until the newly started timer expires.

[0065] Furthermore, if the internal pressure value falls below the danger threshold and then rises to a value higher than the danger threshold but lower than the warning threshold, the timer control unit 130 can continue the timer without restarting it. In other words, if the internal pressure value, which has decreased to below the danger threshold, rises to a value higher than the danger threshold but lower than the warning threshold, the timer control unit 130 can continue the timer without stopping or restarting (resetting) it.

[0066] The alarm unit 150 performs processing related to alarms based on internal pressure values ​​that are based on warning thresholds or danger thresholds. Specifically, the alarm unit 150 can output warning information (warning) corresponding to a warning threshold or danger information (danger) corresponding to a danger threshold.

[0067] The alarm unit 150 can send warning or danger messages to a designated destination that has a corresponding relationship with the user 80. The designated destination can be the email address of the user 80 or the driver of the vehicle 20, or the ECU (Electronic Control Unit) installed in the vehicle 20.

[0068] The alarm unit 150 outputs a warning message when the internal pressure value obtained by the tire data acquisition unit 110 is below a warning threshold. Additionally, the alarm unit 150 outputs a danger message when the internal pressure value is below a danger threshold.

[0069] Specifically, the alarm unit 150 can output a warning message until the timer started by the timer control unit 130 expires when the internal pressure value is below the warning threshold. Additionally, the alarm unit 150 can output a danger message until the timer expires when the internal pressure value is below the danger threshold. In other words, the alarm unit 150 can continue outputting warning or danger messages until the timer expires.

[0070] Furthermore, the alarm unit 150 may not output a warning message if the internal pressure value acquired by the tire data acquisition unit 110 falls below the danger threshold but then becomes higher than the danger threshold but lower than the warning threshold. In this case, as described above, the timer that was started (restarted) due to the pressure dropping below the danger threshold may continue without being reset.

[0071] (4) Operation of the tire pressure monitoring system

[0072] Next, the operation of the tire pressure monitoring system 10 will be explained. Specifically, the operation related to the output of warning information (warning) and danger information (danger) of the internal pressure value by the tire condition monitoring server 100 will be explained.

[0073] (4.1) Summary of Action Flow

[0074] Figure 5 This shows a summary of the action flow for the alarm output of the internal pressure value by the tire condition monitoring server 100. (Example:) Figure 5 As shown, the tire condition monitoring server 100 obtains the internal pressure value of the tire 30 (S10).

[0075] Specifically, the tire condition monitoring server 100 obtains the internal pressure value based on tire data sent from the sensor unit 40.

[0076] The tire condition monitoring server 100 performs a warning / hazard determination (S20) based on the acquired tire pressure value. Specifically, the tire condition monitoring server 100 determines whether the acquired tire pressure value is lower than a warning threshold or a hazard threshold. As described above, the warning threshold can be set to a value that represents a 5% to 10% decrease in the recommended tire pressure value, and the hazard threshold can be set to a value that represents approximately a 20% decrease in the recommended tire pressure value. Below, examples are shown where the warning threshold is a 10% decrease in the recommended tire pressure value and the hazard threshold is a 20% decrease in the recommended tire pressure value.

[0077] The tire condition monitoring server 100 starts or restarts a timer based on the warning / danger determination result of the internal pressure value (S30). For example, the tire condition monitoring server 100 starts the timer when the internal pressure value falls below the warning threshold. Alternatively, the tire condition monitoring server 100 can restart the timer if the internal pressure value falls below a danger threshold that is lower than the warning threshold during the period until the started timer expires.

[0078] Furthermore, the tire condition monitoring server 100 can restart the timer when the internal pressure value rises above the warning threshold after falling below the warning threshold or danger threshold, that is, when the internal pressure value returns to normal.

[0079] Furthermore, restarting a timer can mean restarting a timer that was started due to the internal pressure value dropping below the warning threshold, if the internal pressure value further drops below the danger threshold. More broadly, it means restarting a timer when the internal pressure value is lower than the warning threshold, and the severity changes—specifically, from below the warning threshold to below the danger threshold, or from below the danger threshold to above the danger threshold but below the warning threshold.

[0080] On the other hand, starting a new timer means starting the timer when the internal pressure value, which was once below the warning or danger threshold, rises above the warning threshold.

[0081] The tire condition monitoring server 100 outputs an alarm based on the internal pressure value (S40). Specifically, the tire condition monitoring server 100 outputs warning or danger information based on the internal pressure value.

[0082] In addition, the time from the start of the timer to its expiration can be appropriately set according to the type of vehicle 20 and / or tires 30, the usage environment, etc.

[0083] (4.2) Action Examples

[0084] The following describes a specific example of the alarm output of the internal pressure value by the tire condition monitoring server 100.

[0085] Figure 6 This example demonstrates an alarm output for a previous internal pressure value. In this example, the recommended internal pressure (specified internal pressure) is 120 psi (pounds per square inch). Additionally, in this example, the warning threshold (warning) is set at a 10% decrease in the recommended internal pressure (108 psi), and the danger threshold (danger) is set at a 20% decrease in the recommended internal pressure (96 psi). Furthermore, the internal pressure value can be repeatedly acquired, for example, at 5-minute intervals.

[0086] Alternatively, bar or kPa can be used instead of psi. Additionally, a catastrophic threshold can be established corresponding to internal pressure values ​​lower than the danger threshold. Values ​​related to these internal pressure values ​​can be appropriately set by the user.

[0087] like Figure 6 As shown, when the timer is not used to determine whether the acquired internal pressure value is below the warning threshold or danger threshold and to output warning or danger information, the generation and cessation of warning or danger information are sometimes repeated frequently.

[0088] This phenomenon is mainly caused by at least one of the following factors: the accuracy (measurement error) of the sensor unit 40 (pressure sensor 43) and the temperature variation of the air chamber inside the tire 30, which causes the internal pressure value to fluctuate around the threshold.

[0089] In actions like this, where warning or danger information (alarms) is directly output based on the obtained internal pressure value, a high frequency of the generation and cessation of warning or danger information can easily become a problem.

[0090] Specifically, the frequent generation and cessation of alarms places a significant load on the tire condition monitoring server 100. Furthermore, the frequent generation and cessation of alarms can be frustrating for the user 80. Moreover, it can be argued that even the use of a counter, as disclosed in Non-Patent Document 1, is insufficient to resolve the aforementioned problems in the case of frequent alarm generation and cessation.

[0091] Figure 7 This embodiment demonstrates an example of the alarm output for the internal pressure value. To more reliably address the aforementioned problems, a time limit is applied to the output of warning and danger information (alarms) related to the internal pressure value.

[0092] Specifically, even if a phenomenon becomes equivalent to a warning or danger message, that is, the internal pressure value falls below the warning threshold or the danger threshold, the phenomenon can be ignored for a specified period of time, that is, until the set time of the timer has elapsed.

[0093] As mentioned above, the timer can be started (or restarted) whenever a phenomenon equivalent to a warning or danger message (also known as an open issue) occurs. The timer can be restarted when the phenomenon changes from a warning to a danger, that is, when the severity of the phenomenon increases.

[0094] In addition, an issue can refer to an event (internal processing identifier) ​​that is related to an adverse phenomenon mentioned above, from its occurrence to its resolution.

[0095] The timer that is restarted may also be set at a different time than the timer that was started when the threshold for warning was below (e.g., for a short period of time). Additionally, the timer that was started when the threshold for danger was below may also be set at a different time than the timer that was started when the threshold for warning was below.

[0096] On the other hand, when the internal pressure value changes from a danger level to a warning level, that is, when the internal pressure value drops below the danger threshold and rises above the danger threshold but below the warning threshold, the tire condition monitoring server 100 can ignore such a change and allow the timer to continue without stopping or restarting (resetting) it.

[0097] Additionally, if the internal pressure value rises above the warning threshold after falling below it (i.e., after the internal pressure drop issue has been resolved), a new timer can be started. In this case, the timer's set time can be the same as the timer started when it previously fell below the warning threshold, but it can also be changed.

[0098] Therefore, phenomena that are equivalent to warning or danger messages (including those that change from warning to danger) that occur from the time the internal pressure drop problem is resolved until the timer expires can be ignored.

[0099] In this way, the tire condition monitoring server 100 can start a timer (also known as the first timer) when a phenomenon equivalent to a warning message or danger message occurs, and start other timers (also known as the second timer) when the phenomenon equivalent to the warning message disappears.

[0100] Furthermore, the timer's set time can be dynamically changed based on the number of times the phenomenon stops (the number of repetitions). For example, if the number of repetitions exceeds a predetermined number (the first predetermined number), the timer's set time can be extended. Conversely, if the number of repetitions is less than a predetermined number (the second predetermined number), the timer's set time can be shortened.

[0101] Furthermore, if a danger message is output during the output of a warning message, the warning message can be stopped. Also, if an internal pressure value equivalent to a warning or danger message is obtained a specified number of times consecutively, an alarm corresponding to the warning or danger message can be output regardless of whether the timer has expired. On the other hand, if a normal internal pressure value exceeding the warning threshold is obtained a specified number of times consecutively, the alarm corresponding to the warning or danger message can be stopped regardless of whether the timer has expired.

[0102] (5) Effects

[0103] According to the above-described implementation, the following effects can be achieved. Specifically, the tire pressure monitoring system 10 can restart the timer if, during the period until the timer expires, the internal pressure value rises above the warning threshold after falling below or exceeding the warning threshold.

[0104] Therefore, when the internal pressure value of tire 30 is determined to return to normal, the output of warning or danger information can be controlled based on the new timer setting time, and warning or danger information can be reported at the appropriate time and period.

[0105] In particular, even when the internal pressure value fluctuates around the threshold that serves as the alarm reference, the frequency of alarm (warning or danger information) generation and cessation can be reduced, i.e., the risk of so-called "false positive" alarms. This reduces the load on the tire pressure monitoring system 10 and also avoids user annoyance. That is, the tire pressure monitoring system 10 can prevent the frequent generation and cessation of alarms and output an alarm for decreased internal pressure at the appropriate time.

[0106] In this embodiment, the tire pressure monitoring system 10 does not restart the timer until the timer that was newly started when the tire pressure rises above the warning threshold expires, even if the internal pressure value falls below the warning threshold or danger threshold. Therefore, warning or danger information can be reported at a more appropriate time and period.

[0107] In this embodiment, if the tire pressure monitoring system 10 changes from an internal pressure value below a danger threshold to a value above a danger threshold but below a warning threshold, it can continue to use the timer without outputting a warning message. Therefore, it avoids outputting alarms with low necessity, further reduces the load on the tire pressure monitoring system 10, and more reliably prevents user frustration.

[0108] (6) Other implementation methods

[0109] The above describes the implementation method, but it is not limited to the description of this implementation method. Of course, those skilled in the art can make various modifications and improvements.

[0110] For example, in the above embodiment, the tire condition monitoring server 100 is described as being implemented by connecting to the communication network 70 and executing computer programs (software) on hardware such as a server computer. However, some or all of the functions of the tire condition monitoring server 100 may also be provided virtually by a combination of services provided on a network cloud (not shown).

[0111] In addition, in the above embodiment, the sensor unit 40 has the function of performing wireless communication with the base station 60 in accordance with LPWA, but it may also have the function of performing wireless communication with the vehicle 20 using short-range wireless method as in the past.

[0112] Embodiments of the present invention have been described above; however, the discussions and drawings that form part of this disclosure should not be construed as limiting the invention. Various alternative embodiments, examples, and techniques will become apparent to those skilled in the art based on this disclosure.

[0113] Explanation of reference numerals in the attached figures

[0114] 10: Tire pressure monitoring system; 20: Vehicle; 21: Front axle; 22: Rear axle; 30: Tire; 40: Sensor unit; 41: Temperature sensor; 43: Pressure sensor; 44: Acceleration sensor; 45: Sensor ID setting unit; 47: Wireless communication unit; 49: Battery; 60: Base station; 70: Communication network; 80: User; 100: Tire status monitoring server; 110: Tire data acquisition unit; 130: Timer control unit; 150: Alarm unit.

Claims

1. A tire pressure monitoring system, comprising: The acquisition unit repeatedly acquires the internal pressure value of the inflated tire; The timer control unit starts the timer when the internal pressure value falls below a warning threshold; and The alarm unit outputs a warning message until the timer expires when the internal pressure value is below the warning threshold but above a danger threshold lower than the warning threshold; and outputs a danger message until the timer expires when the internal pressure value is below the danger threshold. in, The timer control unit restarts the timer if, during the period until the timer expires, the internal pressure value rises above the warning threshold after falling below it.

2. The tire pressure monitoring system according to claim 1, wherein, The timer control unit will not restart the timer until the newly started timer expires, even if the internal pressure value falls below the warning threshold.

3. The tire pressure monitoring system according to claim 1 or 2, wherein, If the internal pressure value falls below the danger threshold and then becomes higher than the danger threshold but lower than the warning threshold, the alarm unit will not output the warning message. The timer control unit causes the timer to continue.

4. A computer program product comprising a tire pressure monitoring program, the tire pressure monitoring program causing a computer to perform the following processes: The process involves repeatedly acquiring the internal pressure value of the inflated tire. Timer control processing, starting the timer when the internal pressure value falls below a warning threshold; and Alarm processing: If the internal pressure value is below the warning threshold but above a danger threshold lower than the warning threshold, a warning message will be output until the timer expires; if the internal pressure value is below the danger threshold, a danger message will be output until the timer expires. in, In the timer control process, if the internal pressure value rises above the warning threshold after falling below it during the period until the timer expires, the timer is restarted.

5. A tire pressure monitoring method, comprising the following steps: Repeat the steps of obtaining the internal pressure value of the inflated tire; A timer is started if the internal pressure value falls below the warning threshold. as well as If the internal pressure value is below the warning threshold but above a danger threshold lower than the warning threshold, a warning message will be output until the timer expires. If the internal pressure value is below the danger threshold, a danger message will be output until the timer expires. Specifically, in the step of starting the timer, if the internal pressure value rises above the warning threshold after falling below it during the period until the timer expires, the timer is restarted.

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