WO2018056115A1 - Tire air pressure monitoring system and monitoring device - Google Patents

Abstract

The present invention provides a tire air pressure monitoring system and monitoring device which monitor the natural depressurization of tire air pressure and provide notification of the appropriate timing for filling the tire in accordance with the natural depressurization. The monitoring device is provided with: a storage unit which associates air pressure information included in a received air pressure signal with date information that indicates the date at which a detection device detected the air pressure, and stores said information; a determination unit which determines whether or not it is a timing at which notification should be provided of air pressure information for each tire; and an output unit which outputs air pressure information for each tire read from the storage unit when it is determined to be the timing at which notification should be provided.

Description

Tire pressure monitoring system and monitoring device

The present invention relates to a tire pressure monitoring system and a monitoring device.
This application claims priority based on Japanese Patent Application No. 2016-185750 filed on September 23, 2016, and incorporates all the description content described in the above Japanese application.

There is a tire pressure monitoring system (TPMS: Tire Pressure Monitoring System) that detects the air pressure of a tire provided in a vehicle and issues a warning to the user when the detected air pressure is abnormal (for example, Patent Document 1). See).

The tire pressure monitoring system includes a detection device provided on each tire and a monitoring device disposed on the vehicle body. The detection device detects the air pressure of the tire and wirelessly transmits an air pressure signal including air pressure information obtained by detection using an RF band (RF: 帯 Radio Frequency) radio wave. The monitoring device receives the air pressure signal transmitted from each detection device, and monitors the air pressure of each tire based on the received air pressure signal. When there is an abnormality in the tire air pressure, the monitoring device displays a warning on the tire air pressure abnormality and issues a warning.

JP 62-125905 A

In the conventional tire pressure monitoring system, a warning can be issued if there is an abnormality in the detected tire pressure, but the natural pressure reduction of the tire pressure is monitored, and an appropriate filling timing is set according to the natural pressure reduction. It has a problem that it cannot be notified.

An object of the present invention is to provide a tire pressure monitoring system and a monitoring device capable of monitoring a natural pressure reduction of a tire pressure and notifying an appropriate filling timing according to the natural pressure reduction.

The tire pressure monitoring system according to this aspect is provided in each of a plurality of tires of a vehicle, and a plurality of detection devices that wirelessly transmit a pneumatic pressure signal including air pressure information obtained by detecting the pressure of the tires, and the detection A tire pressure monitoring system comprising: a monitoring device that receives the air pressure signal transmitted from the device and monitors the air pressure of each tire, wherein the monitoring device detects the air pressure information included in the received air pressure signal; A storage unit that stores data associated with date information indicating the date when the air pressure is detected, a determination unit that determines whether or not to notify the air pressure information of each tire, and a timing that should be notified In this case, an output unit that outputs the air pressure information of each tire read from the storage unit is provided.

The monitoring device according to this aspect is provided in each of a plurality of tires of a vehicle, and the air pressure transmitted from a plurality of detection devices that wirelessly transmit air pressure signals including air pressure information obtained by detecting the air pressure of the tires. A monitoring device that receives the signal and monitors the air pressure of each tire, and stores the air pressure information included in the received air pressure signal in association with date information indicating a date when the detection device detects the air pressure; A determination unit that determines whether or not it is time to notify the pressure information of each tire, and an output unit that outputs the pressure information of each tire read from the storage unit when it is determined that it is time to notify With.

According to the above, it is possible to monitor the natural pressure reduction of the tire pressure and notify an appropriate filling timing according to the natural pressure reduction.

It is a schematic diagram which shows the structural example of the tire pressure monitoring system which concerns on Embodiment 1. FIG. It is a block diagram explaining the internal structure of a monitoring apparatus. It is a conceptual diagram which shows an example of a sensor identifier table. It is a block diagram explaining the internal structure of a detection apparatus. It is a flowchart explaining the procedure of the process which a monitoring apparatus performs when acquiring air pressure information. It is a conceptual diagram which shows an example of an air pressure management table. It is a flowchart explaining the procedure of the process which a monitoring apparatus performs when outputting pneumatic pressure information. It is a schematic diagram which shows the example of alerting | reporting by an alerting | reporting apparatus. 10 is a flowchart illustrating a procedure of processing executed by the monitoring apparatus according to the second embodiment. 14 is a flowchart illustrating a procedure of processing executed by the monitoring apparatus according to the third embodiment.

Embodiments of the present invention will be listed and described. Moreover, you may combine arbitrarily at least one part of embodiment described below.

A tire pressure monitoring system according to an aspect of the present application is provided in each of a plurality of tires of a vehicle, and a plurality of detection devices that wirelessly transmit a pressure signal including air pressure information obtained by detecting the pressure of the tires; A tire pressure monitoring system comprising: a monitoring device that receives the air pressure signal transmitted from the detection device and monitors the air pressure of each tire, wherein the monitoring device converts the air pressure information included in the received air pressure signal, A storage unit that stores information related to date information indicating a date when the detection device detects the air pressure, a determination unit that determines whether or not it is time to notify the air pressure information of each tire, and a timing that should be notified And an output unit that outputs the air pressure information of each tire read from the storage unit.

In the above aspect, the air pressure of each tire is detected and stored in the storage unit, and the value of the air pressure of each tire is output at the set notification timing. It can be grasped quantitatively.

In the tire pressure monitoring system according to one aspect of the present application, the timing to be notified is a set periodic timing.

In the above aspect, the air pressure of each tire is detected and stored in the storage unit, and the value of the air pressure of each tire is output at a regular timing. Can be grasped.

In the tire pressure monitoring system according to one aspect of the present application, the monitoring device refers to the storage unit, and determines whether or not the amount of decrease in air pressure in a predetermined period is equal to or greater than a threshold value for each tire. When there is a tire for which the amount of decrease in the air pressure is determined to be equal to or greater than the threshold, the determination unit determines that it is time to notify the air pressure information of each tire.

In the above aspect, when the amount of decrease in the air pressure during the predetermined period is equal to or greater than the threshold value, information on the air pressure of each tire is output, so that the occupant can know the presence of a tire having a greater degree of decompression than natural decompression. it can.

In the tire pressure monitoring system according to one aspect of the present application, the monitoring device includes a calculation unit that calculates a time when each tire should be filled with air based on air pressure information stored in the storage unit, and the output unit includes: The information of the time calculated by the calculation unit is output.

In the above aspect, since the time when each tire should be filled with air is calculated and output based on the air pressure information stored in the storage unit, the occupant knows when each tire should be filled with air. can do.

In the tire pressure monitoring system according to one aspect of the present application, the monitoring device is detected by the detection device based on an acquisition unit that acquires temperature information from a measurement sensor that measures a temperature outside the vehicle, and the acquired temperature information. A correction unit that corrects the air pressure value, and when the air pressure information is received from the detection device, the air pressure value included in the air pressure information is corrected by the correction unit and includes the corrected air pressure value. Information is stored in the storage unit.

In the above aspect, since the air pressure value is corrected based on the temperature information, it is possible to notify the occupant of the air pressure of each tire excluding the increase and decrease in pressure due to temperature.

The monitoring device according to an aspect of the present application is provided in each of a plurality of tires of a vehicle, and is transmitted from a plurality of detection devices that wirelessly transmit air pressure signals including air pressure information obtained by detecting air pressure of the tires. A monitoring device that receives the air pressure signal and monitors the air pressure of each tire, and stores air pressure information included in the received air pressure signal in association with date information indicating a date on which the detection device detects the air pressure. Section, a determination section for determining whether or not it is time to notify the pressure information of each tire, and if it is determined that it is time to notify, output the pressure information of each tire read from the storage section And an output unit.

In the above aspect, the air pressure of each tire is detected and stored in the storage unit, and the value of the air pressure of each tire is notified at the set notification timing. It can be grasped quantitatively.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a configuration example of a tire air pressure monitoring system according to the first embodiment. The tire pressure monitoring system according to the first embodiment includes a monitoring device 1 provided at an appropriate position of a vehicle body, a detection device 2 provided on each of the wheels of a plurality of tires 3 provided on the vehicle C, and a notification device 4. With. In the tire pressure monitoring system of the first embodiment, the monitoring device 1 acquires the air pressure of each tire 3 by performing unidirectional or bidirectional wireless communication with each detection device 2, and the notification device 4 acquires the acquired air pressure. Notification according to is performed.

The monitoring device 1 is connected to a plurality of LF transmission antennas 14a that perform wireless communication with a plurality of detection devices 2 provided in each tire 3. For example, the LF transmission antenna 14a is provided at the front and rear of the vehicle C. The right front and left front tire positions are included in the communication range 1a of the LF transmission antenna 14a provided at the front of the vehicle C, and the right rear and left rear tire positions are LF transmission antennas provided at the rear of the vehicle C. 14a is included in the communication range 1b. The communication range 1a is a range in which the detection device 2 can receive a signal transmitted from the LF transmission antenna 14a at the front of the vehicle. Similarly, the communication range 1b is a range in which the detection device 2 can receive a signal transmitted from the LF transmission antenna 14a at the rear of the vehicle.

The monitoring device 1 transmits a request signal for requesting the air pressure information of the tire 3 to each of the plurality of detection devices 2 by radio waves in the LF band (LF: Low Frequency) from each LF transmitting antenna 14a. The detection device 2 detects the air pressure of the tire 3 in response to the request signal of the monitoring device 1, and sends the air pressure signal including the air pressure information obtained by the detection and its own sensor identifier to the monitoring device 1 by radio waves in the RF band. Send. The monitoring device 1 includes an RF receiving antenna 13a, and receives an air pressure signal transmitted from each detection device 2 by the RF receiving antenna 13a. As will be described later, the monitoring device 1 stores the relationship between each tire position where the tire 3 is provided and the sensor identifier of the detection device 2 provided on the tire 3 at the tire position. The air pressure information of each tire 3 can be determined using the sensor identifier.

Note that the LF band and the RF band are examples of a radio wave band used when performing wireless communication, and are not necessarily limited thereto. The monitoring device 1 is connected to the notification device 4 via a communication line, and the monitoring device 1 transmits the acquired air pressure information to the notification device 4. The notification device 4 receives the air pressure information transmitted from the monitoring device 1 and notifies the air pressure of each tire 3 at a predetermined timing.

In the present embodiment, the monitoring device 1 acquires the air pressure information by transmitting the request signal from the monitoring device 1 and receiving the air pressure signal transmitted from the detection device 2 as the response. The configuration may be such that the monitoring device 1 acquires the air pressure information of each tire by receiving the air pressure signal spontaneously transmitted from the detection device 2 during traveling. In addition, the monitoring device 1 uses a combination of a method for transmitting a request signal from the monitoring device 1 and receiving a pneumatic signal from the detection device 2 and a method for receiving a pneumatic signal spontaneously transmitted from the detection device 2. The structure which acquires the air pressure information of each tire may be sufficient.

FIG. 2 is a block diagram illustrating the internal configuration of the monitoring device 1. The monitoring device 1 includes a control unit 11 that controls the operation of each component of the monitoring device 1. A storage unit 12, an in-vehicle receiving unit 13, an in-vehicle transmitting unit 14, an output unit 15, and an input unit 16 are connected to the control unit 11.

The control unit 11 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface, and the like. The CPU of the control unit 11 is connected to the storage unit 12, the in-vehicle receiving unit 13, the in-vehicle transmitting unit 14, the output unit 15, and the input unit 16 through an input / output interface. The control unit 11 controls the operation of each component by executing a control program stored in the storage unit 12 and executes a tire pressure monitoring process and the like according to the first embodiment. The control unit 11 includes a clock unit that counts the elapsed time from when the measurement start instruction is given to when the measurement end instruction is given, a clock unit that outputs information related to the date and time, and a counting unit that counts the number Etc. may be provided.

The storage unit 12 is a nonvolatile memory such as an EEPROM (ElectricallyrErasable Programmable ROM) or a flash memory. The storage unit 12 stores a control program for executing tire pressure monitoring processing and the like by the control unit 11 controlling the operation of each component of the monitoring device 1. The storage unit 12 includes a sensor identifier table and an air pressure management table described later.

FIG. 3 is a conceptual diagram showing an example of a sensor identifier table. The sensor identifier table stores a plurality of tire positions in association with sensor identifiers of the detection device 2 provided on the tire 3 at the tire position. In the example shown in FIG. 3, sensor identifiers A, B, C, and D are associated with front right, right rear, left rear, and left front tire positions, respectively.

The RF receiving antenna 13 a is connected to the in-vehicle receiving unit 13. The in-vehicle receiving unit 13 receives a signal transmitted from the detection device 2 using an RF band radio wave by the RF receiving antenna 13a. The in-vehicle receiving unit 13 is a circuit that demodulates the received signal and outputs the demodulated signal to the control unit 11. An RF band of 300 MHz to 3 GHz is used as a carrier wave, but the carrier wave is not limited to this frequency band.

The in-vehicle transmission unit 14 is a circuit that modulates the signal output from the control unit 11 into an LF band signal and transmits the modulated signal to the plurality of detection devices 2 from the plurality of LF transmission antennas 14a. As a carrier wave, an LF band of 30 kHz to 300 kHz is used, but the carrier wave is not limited to this frequency band.

The output unit 15 includes a communication circuit that performs communication in accordance with a communication protocol such as CAN (Controller Area Network) or LIN (Local Interconnect Network), and is connected to, for example, the notification device 4. The output unit 15 transmits information related to the air pressure of the tire 3 to the notification device 4 under the control of the control unit 11.

The notification device 4 is, for example, a display unit or a display unit provided in an instrument panel instrument, which is provided with a display unit or a speaker that notifies information related to the air pressure of the tire 3 transmitted from the output unit 15 by an image or sound. Etc. The display unit is a liquid crystal display, an organic EL display, an MID (Multi Information Display), or the like.

The input unit 16 is connected with a temperature sensor 5, an ignition switch 6 (IG switch 6), and the like. The temperature sensor 5 is provided at an appropriate position of the vehicle C, measures the temperature outside the vehicle, and outputs the measurement result. A measurement result by the temperature sensor 5 is input to the control unit 11 through the input unit 16. Also, an ignition switch signal (hereinafter referred to as an IG switch signal) corresponding to the operation state of the ignition switch 6 is input to the input unit 16, and the control unit 11 is based on the IG switch signal input from the input unit 16. Thus, the operation state of the ignition switch 6 can be recognized.

FIG. 4 is a block diagram illustrating the internal configuration of the detection apparatus 2. The detection device 2 includes a sensor control unit 21 that controls the operation of each component of the detection device 2. A sensor storage unit 22, a sensor transmission unit 23, a sensor reception unit 24, an air pressure detection unit 25, and a timer unit 26 are connected to the sensor control unit 21.

The sensor control unit 21 is a microcomputer having, for example, one or a plurality of CPUs, a multi-core CPU, a ROM, a RAM, an input / output interface, and the like. The CPU of the sensor control unit 21 is connected to the sensor storage unit 22, the sensor transmission unit 23, the sensor reception unit 24, the air pressure detection unit 25, and the time measurement unit 26 via an input / output interface. The sensor control unit 21 reads a control program stored in the sensor storage unit 22 and controls each unit. The detection device 2 includes a battery (not shown), and is configured to operate with electric power from the battery.

The sensor storage unit 22 is a nonvolatile memory. The sensor storage unit 22 stores a control program for the CPU of the sensor control unit 21 to perform processing related to detection and transmission of the air pressure of the tire 3. Further, a unique sensor identifier for identifying itself and the other detection device 2 is stored.

The air pressure detection unit 25 includes a diaphragm, for example, and detects the air pressure of the tire 3 based on the deformation amount of the diaphragm that changes depending on the magnitude of the pressure. The air pressure detection unit 25 outputs a signal indicating the detected air pressure of the tire 3 to the sensor control unit 21. In addition, you may provide the temperature detection part (not shown) which detects the temperature of the tire 3 and outputs the signal which shows the detected temperature to the sensor control part 21. FIG.

The sensor transmission unit 23 is connected to an RF transmission antenna 23a. The sensor transmission unit 23 modulates the air pressure signal generated by the sensor control unit 21 into an RF band signal, and transmits the modulated air pressure signal using the RF transmission antenna 23a.

The sensor receiving unit 24 is connected to an LF receiving antenna 24a. The sensor receiving unit 24 receives various signals such as a request signal transmitted from the monitoring device 1 using radio waves in the LF band by the LF receiving antenna 24 a and outputs the received signals to the sensor control unit 21.

FIG. 5 is a flowchart for explaining a procedure of processing executed by the monitoring device 1 when air pressure information is acquired. The monitoring device 1 executes the following processing at an appropriate timing such as the timing when the ignition switch 6 is turned on from the off state. First, the control unit 11 of the monitoring device 1 controls the in-vehicle transmission unit 14 to transmit a request signal for requesting transmission of a pneumatic signal from the LF transmission antenna 14a (step S101). When the detection device 2 receives the request signal transmitted from the LF transmission antenna 14a, the detection device 2 transmits the air pressure signal including the air pressure information of the tire 3 detected by the air pressure detection unit 25 from the RF transmission antenna 23a.

When the control unit 11 receives the air pressure signal transmitted from the detection device 2 (step S102), the control unit 11 collates the identifier included in the air pressure signal with the identifier registered in the sensor identifier table to thereby determine the tire position. Air pressure information is specified (step S103). In the present embodiment, when a request signal is transmitted from the LF transmission antenna 14a provided at the front portion of the vehicle, a pneumatic signal is transmitted from the detection device 2 provided at the right front and left front tire positions, and the monitoring device 1 Two air pressure signals transmitted from the detection device 2 for each tire position are received. Similarly, when a request signal is transmitted from the LF transmitting antenna 14a provided at the rear of the vehicle, a pneumatic signal is transmitted from the detection device 2 provided at the right rear and left rear tire positions, and the monitoring device 1 is connected to each tire. Two air pressure signals transmitted from the position detecting device 2 are received. Since the communication range 1a of the LF transmission antenna 14a provided in the front part of the vehicle includes a plurality of detection devices 2, the control unit 11 of the monitoring device 1 uses the sensor identifier table to Determine the source. Similarly, since the communication range 1b of the LF transmission antenna 14a provided in the rear part of the vehicle includes a plurality of detection devices 2, the control unit 11 of the monitoring device 1 uses the sensor identifier table to determine each air pressure. Determine the source of the signal.

In this embodiment, since a plurality of detection devices 2 in the communication range 1a of each LF transmission antenna 14a are included, the processing for determining the transmission source of each pneumatic signal is executed. In the configuration in which the LF transmission antenna 14a that individually transmits the request signal to the position is provided and the air pressure signal is received for each tire position, the process of step S103 may be omitted.

Next, the control unit 11 stores the air pressure information of each tire 3 in the air pressure management table in the storage unit 12 in association with the reception date of the air pressure signal (step S104). FIG. 6 is a conceptual diagram showing an example of an air pressure management table. In the air pressure management table, the reception date of the air pressure signal, the temperature outside the vehicle obtained from the temperature sensor 5, and the air pressure information obtained from the air pressure signal are stored in association with each tire 3. The example of FIG. 6 shows a state in which the value of the air pressure of the tire 3 at the left front of the vehicle detected in July of a certain year is stored in association with the reception date of the air pressure signal and the temperature outside the vehicle. The air pressure information stored in the air pressure management table may be the air pressure value of the tire 3 detected by the detection device 2 or the air pressure value corrected by the temperature outside the vehicle. When the air pressure value is corrected by the temperature outside the vehicle, the control unit 11 detects using the relationship that the air pressure of the tire 3 increases (decreases) by 10 kPa every time the temperature increases (decreases) by 10 ° C. The value of the air pressure of the tire 3 detected by the device 2 can be converted (corrected) into the value of the air pressure at a reference temperature (for example, 20 ° C.).

FIG. 7 is a flowchart for explaining a procedure of processing executed by the monitoring apparatus 1 when outputting air pressure information. For example, the monitoring device 1 periodically executes the following processing after the ignition switch 6 is turned on. First, the control unit 11 of the monitoring device 1 determines whether or not the current time is the timing for notifying the air pressure information (step S111). The control unit 11 refers to the built-in clock unit and determines whether or not the current timing is the notification timing by determining whether or not the set timing (for example, once a month) has been reached. Good. Note that the notification timing may be an arbitrary timing set by a passenger, or may be a timing set in advance at the time of manufacturing or selling. In addition, the control unit 11 compares the latest air pressure value stored in the air pressure management table with the threshold value set for the air pressure, and determines that it is a notification timing when the latest air pressure value is equal to or less than the threshold value. Also good. When it is determined that it is not the notification timing (S111: NO), the control unit 11 ends the process according to this flowchart.

When it is determined that it is the notification timing (S111: YES), the control unit 11 outputs information related to the air pressure value read from the air pressure management table of the storage unit 12 to the notification device 4 (step S112). The controller 11 may be configured to read out only the latest value stored in the air pressure management table, or may be configured to read out the latest value and a value before a predetermined period (for example, one month before). Good. Moreover, the structure which reads the value of the air pressure of the arbitrary days designated by crew members, such as a driver | operator, may be sufficient as the control part 11. FIG.

When the information related to the value of the air pressure is input from the control unit 11, the notification device 4 notifies the value related to the air pressure in a predetermined notification mode. FIG. 8 is a schematic diagram showing an example of notification by the notification device 4. The example shown in FIG. 8 shows a state in which the value of the air pressure of each tire 3 is displayed in units of kilopascals (kPa) together with the icons of the vehicle C and each tire 3. For example, FIG. 8A shows an example of displaying the air pressure value of each tire 3 on June 30 of a certain year, and FIG. 8B shows an example of displaying the air pressure value of each tire 3 on July 31 of the same year. Is shown. Since the notification device 4 displays the value of the air pressure input from the control unit 11, it may be configured to display only the latest value (for example, the value shown in FIG. 8B). A configuration in which values (for example, values shown in FIGS. 8B and 8A) are alternately displayed may be employed. Moreover, the structure which displays the value of the air pressure of the arbitrary days designated by the passenger | crew may be sufficient as the alerting | reporting apparatus 4.

As described above, in the first embodiment, the air pressure of each tire 3 is periodically detected and stored in the air pressure management table, and the value of the air pressure of each tire is notified at an appropriate timing. As a result, the amount of natural pressure reduction can be quantitatively grasped, and the timing at which each tire should be filled with air can be predicted.

(Embodiment 2)
In the second embodiment, a configuration will be described in which the amount of decrease in air pressure (reduced pressure value) of each tire during a predetermined period is calculated, and when the calculated amount of decrease is greater than or equal to a threshold value, the value of the air pressure of each tire is notified.

FIG. 9 is a flowchart showing a procedure of processing executed by the monitoring apparatus 1 according to the second embodiment. The monitoring device 1 executes the following processing at an appropriate timing such as the timing when the ignition switch 6 is turned on from the off state. The control unit 11 of the monitoring device 1 reads the latest air pressure value of each tire 3 stored in the air pressure management table and the air pressure value before a predetermined period (for example, one month before), and within the predetermined period The amount of decrease in the air pressure of each tire is calculated (step S201).

Next, the control unit 11 determines whether or not the calculated amount of decrease is equal to or greater than a threshold value (step S202). The threshold value is stored in the storage unit 12 and may be a preset value or a value set by an occupant or the like. In addition, since general natural decompression is 10 to 20 kPa per month, the threshold can be set to 20 kPa, for example.

When it is determined that the calculated decrease amount is less than the threshold (S202: NO), the control unit 11 ends the process according to this flowchart. On the other hand, when it is determined that the calculated decrease amount is equal to or greater than the threshold (S202: YES), the control unit 11 outputs information related to the value of the air pressure read from the air pressure management table to the notification device 4 (step S203). At this time, the control unit 11 may be configured to output only information related to the latest air pressure value, or may be configured to output both the latest air pressure value and the air pressure value before a predetermined period. Good.

When the information related to the value of the air pressure is input from the control unit 11, the notification device 4 notifies the value related to the air pressure in a predetermined notification mode. For example, as shown in FIG. 8, the notification device 4 can display the value of the air pressure of each tire 3 in units of kilopascals (kPa) together with the icons of the vehicle C and each tire 3. In addition, in order to explicitly display the tire 3 whose amount of decrease is equal to or greater than the threshold, the icon and the air pressure value corresponding to the tire 3 are displayed in different colors or blinked. Also good.

As described above, in the second embodiment, when the amount of decrease in air pressure per predetermined period (for example, one month) is equal to or greater than the threshold value, the passenger can be notified of this, so that the passenger can reduce the pressure more than the natural pressure reduction. It is possible to grasp the presence of a tire having a large degree of.

(Embodiment 3)
In the third embodiment, a configuration for notifying the time when the air pressure should be filled based on the value of the air pressure of each tire stored in the air pressure management table will be described.

FIG. 10 is a flowchart showing a procedure of processing executed by the monitoring apparatus 1 according to the third embodiment. The monitoring device 1 executes the following processing at an appropriate timing such as the timing when the ignition switch 6 is turned on from the off state. The control unit 11 of the monitoring device 1 reads the latest air pressure value of each tire 3 stored in the air pressure management table and the air pressure value before a predetermined period (for example, one month before), and within the predetermined period The amount of decrease in air pressure of each tire 3 is calculated (step S301).

Next, the control unit 11 calculates the time when each tire 3 should be filled with air based on the calculated amount of decrease in the air pressure of each tire 3 (step S302). When the initial value of air pressure (value before a predetermined period) is P0, the amount of decrease per month is ΔP, and the air pressure of the tire 3 indicating the filling time is P1, the time to be filled is, for example, (P0−P1) / It can be calculated by ΔP. In the present embodiment, the air pressure of each tire 3 is detected over time, and the value of the detected air pressure is stored in the air pressure management table. Therefore, the change in the air pressure of each tire 3 can be represented by a straight line or an arbitrary curve. It is good also as a structure which calculates the time which should be filled based on the approximated straight line or curve obtained.

The control unit 11 outputs information on the calculated filling timing to the notification device 4 (step S303), and causes the notification device 4 to notify the filling timing of air into each tire 3.

As described above, according to the third embodiment, the air filling time for each tire 3 is calculated and notified based on the air pressure management table that stores the air pressure value of each tire 3 over time. Can grasp the filling time of air into each tire 3.

In the first to third embodiments, the first embodiment related mainly to the tire pressure monitoring system has been described. However, the hardware related to the wireless communication of the tire pressure monitoring system may also be used as another communication system. For example, the vehicle communication system of TPMS and passive entry system may be configured by sharing hardware related to wireless communication.

The passive entry system includes the monitoring device 1 and a portable device related to the passive entry system. The monitoring device 1 performs wireless communication with a portable device possessed by the user, authenticates the portable device, and detects the position of the portable device. A touch sensor (not shown) is provided on the door handle of the vehicle C. When the touch sensor detects that the user's hand has touched the door handle, or when the door switch is pressed, a regular portable device is provided. Is located outside the vehicle, the monitoring device 1 executes processing such as locking and unlocking the door of the vehicle C. In the first to third embodiments, the LF transmission antennas 14a and 14a are provided at the front and rear portions of the vehicle C. However, one LF transmission antenna 14a is provided near the doorknob of the vehicle door provided on the right side of the vehicle C. The communication range of the LF transmission antenna 14a includes the right front and right rear tire positions, and the other LF transmission antenna 14a is provided near the door knob of the vehicle door provided on the left side of the vehicle C. The communication range 14a may include the front left and rear left tire positions. The monitoring device 1 sets the transmission intensity of the signal transmitted from the LF transmission antenna 14a high when performing wireless communication with the portable device, and transmits the request signal to the detection device 2 when transmitting the request signal to the detection device 2. The transmission intensity of the signal transmitted from may be set low.

In addition, the passive entry system which comprises the communication system for vehicles is an example, and can apply this invention to the system which performs wireless communication between a portable machine and the monitoring apparatus 1, and performs various vehicle control. For example, the vehicle communication system may be configured with a TPMS, a keyless entry system, a smart start (registered trademark) system that can start a prime mover mounted on the vehicle C without using a mechanical key, and the like.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Monitoring apparatus 1a, 1b Communication range 2 Detection apparatus 3 Tire 4 Notification apparatus 5 Temperature sensor 6 Ignition switch 11 Control part 12 Memory | storage part 13 In-vehicle receiving part 13a RF receiving antenna 14 In-vehicle transmitting part 14a LF transmitting antenna 15 Output part 16 Input part DESCRIPTION OF SYMBOLS 21 Sensor control part 22 Sensor memory | storage part 23 Sensor transmission part 23a RF transmission antenna 24 Sensor reception part 24a LF reception antenna 25 Air pressure detection part 26 Timing part C Vehicle

Claims (6)

1. A plurality of detection devices that are respectively provided on a plurality of tires of a vehicle and wirelessly transmit air pressure signals including air pressure information obtained by detecting the air pressure of the tires, and receive the air pressure signals transmitted from the detection devices And a tire pressure monitoring system comprising a monitoring device for monitoring the pressure of each tire,
   The monitoring device
   A storage unit for storing air pressure information included in the received air pressure signal in association with date information indicating a date on which the detection device detects air pressure;
   A determination unit that determines whether or not it is time to notify the air pressure information of each tire;
   A tire pressure monitoring system, comprising: an output unit that outputs the pneumatic pressure information of each tire read from the storage unit when it is determined that the timing is to be notified.
2. The tire pressure monitoring system according to claim 1, wherein the timing to be notified is a set regular timing.
3. The monitoring device
   With reference to the storage unit, an air pressure determination unit that determines for each tire whether the amount of decrease in air pressure in a predetermined period is equal to or greater than a threshold value,
   3. The tire according to claim 1, wherein when there is a tire for which the amount of decrease in the air pressure is determined to be equal to or greater than the threshold, the determination unit determines that it is time to notify the air pressure information of each tire. Air pressure monitoring system.
4. The monitoring device
   Based on the air pressure information stored in the storage unit, a calculation unit that calculates the time when each tire should be filled with air,
   The tire pressure monitoring system according to any one of claims 1 to 3, wherein the output unit outputs information on a time calculated by the calculation unit.
5. The monitoring device
   An acquisition unit that acquires temperature information from a measurement sensor that measures the temperature outside the vehicle;
   A correction unit that corrects the value of the air pressure detected by the detection device based on the acquired temperature information,
   When the air pressure information is received from the detection device, the air pressure value included in the air pressure information is corrected by the correction unit, and the air pressure information including the corrected air pressure value is stored in the storage unit. Item 5. The tire pressure monitoring system according to any one of Items 4 to 5.
6. Each of the tires of the vehicle is provided with each of the tires, and receives the air pressure signals transmitted from the plurality of detection devices that wirelessly transmit air pressure signals including air pressure information obtained by detecting the air pressure of the tires. A monitoring device for monitoring air pressure,
   A storage unit for storing air pressure information included in the received air pressure signal in association with date information indicating a date on which the detection device detects air pressure;
   A determination unit that determines whether or not it is time to notify the air pressure information of each tire;
   A monitoring device comprising: an output unit that outputs air pressure information of each tire read from the storage unit when it is determined that the timing is to be notified.

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