JP2022056921A - Tire condition monitoring system, battery discharge capacity estimation program, and discharge capacity estimation method - Google Patents

Abstract

To provide a tire condition monitoring system, a battery discharge capacity estimation program, and a discharge capacity estimation method capable of more accurately predicting the life of a battery used in a tire condition measurement unit.SOLUTION: This tire condition monitoring system comprises: the step of receiving tire condition data from a tire condition measurement unit (sensor unit SU); the first count step of counting the number of receiving times; the step of receiving the number of operating times of the tire condition measurement unit or data of a cycle number equivalent to standby time together with the tire condition data; the second count step of counting the number of operating times of the tire condition measurement unit or the third count step of counting a cycle number equivalent to the standby time; and the first estimation step of estimating a discharge capacity discharged from the battery for driving the tire condition monitoring system on the basis of the numbers of operating times counted in the first to third steps and a discharge capacity in each operation.SELECTED DRAWING: Figure 3

Description

The present invention relates to a tire condition monitoring system for monitoring the air pressure of a pneumatic tire, a battery discharge capacity estimation program, and a discharge capacity estimation method.

Various technologies related to a tire condition monitoring system (Tire Pressure Monitoring System (TPMS)) for measuring parameters such as air pressure and temperature during vehicle operation have been proposed for a plurality of pneumatic tires mounted on a vehicle. ..

Based on such parameters measured by TPMS, it is possible to detect low tire pressure, air leakage, etc., and notify the driver of the need for maintenance such as tire replacement.

By the way, many sensor units (tire condition measuring units) mounted on tires as a part of a TPMS use a battery (for example, a button battery or the like) provided integrally with the sensor unit itself as a drive power source.

In the sensor unit as described above, the entire device is molded with resin in order to ensure weather resistance and durability, and the structure is such that the battery or the like cannot be replaced. Therefore, it is necessary to predict the life of the battery and perform maintenance such as replacing the sensor unit before the end of the life.

Therefore, a technique for predicting the remaining battery life based on the number of times data is transmitted to the outside of the transmission unit included in the sensor unit has been proposed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-223463

However, since the discharge capacity of the battery varies depending on the manufacturing variation of the battery / substrate, the user of the TPMS, and the usage environment, there is a problem that the battery life cannot be accurately predicted by the conventional technology.

Therefore, the present invention has been made in view of the above problems, and is a tire condition monitoring system capable of more accurately predicting the life of the battery used in the tire condition measuring unit, a battery discharge capacity estimation program, and a battery discharge capacity estimation program. It is an object of the present invention to provide a method for estimating the discharge capacity.

The tire condition monitoring system according to one aspect of the present invention is arranged on the inner surface of a pneumatic tire, and has a tire condition measuring unit that measures tire condition data of the tire, a battery that drives the tire condition measuring unit, and the tire. A tire condition monitoring system including at least a data acquisition unit that acquires the tire condition data from the condition measurement unit, a storage unit that stores the acquired tire condition data, and a discharge capacity estimation unit that estimates the discharge capacity of the battery. The data acquisition unit receives data on the number of operations of the tire condition measurement unit or the number of cycles corresponding to the standby time together with the tire condition data, and the discharge capacity estimation unit receives the tire condition data. The first count step for counting the number of times the tire condition is received is executed, and the second count step for counting the number of operations of the tire condition measuring unit or the third count step for counting the cycle corresponding to the waiting time is executed. The gist is to execute the first estimation step of estimating the discharge capacity discharged by the battery based on the number of operations counted from the first count step to the third count step and the discharge capacity in each operation. ..

As a result, it is possible to accurately calculate the main discharge capacity of the battery that drives the tire condition measuring unit without being affected by the fluctuation of the measurement cycle.

Further, a more accurate discharge capacity can be estimated by considering the discharge capacity and the standby power of the tire condition measuring unit.

Further, it is possible to estimate the remaining battery level with high accuracy based on the usage status of the tire condition measuring unit.

The battery discharge capacity estimation program according to another aspect of the present invention includes a step of receiving tire condition data from a tire condition measuring unit that detects tire pressure, and a first count that counts the number of times the tire condition data is received. The step, the step of receiving the data of the number of operations of the tire condition measuring unit or the number of cycles corresponding to the standby time together with the tire condition data, and the second count step of counting the number of operations of the tire condition measuring unit or , The tire condition measuring unit is based on the third count step for counting the cycle corresponding to the standby time, the number of operations counted from the first count step to the third count step, and the discharge capacity in each operation. It has a first estimation step of estimating the discharged capacity of the driven battery, and is executed by a computer provided with a tire condition monitoring system using the tire condition measuring unit.

As a result, it is possible to accurately calculate the main discharge capacity of the battery that drives the tire condition measuring unit without being affected by the fluctuation of the measurement cycle.

Further, a more accurate discharge capacity can be estimated by considering the discharge capacity and the standby power of the tire condition measuring unit.

Further, it is possible to estimate the remaining battery level with high accuracy based on the usage status of the tire condition measuring unit.

The method for estimating the discharge capacity of the battery according to another aspect of the present invention is a process of receiving tire condition data from a tire condition measuring unit that detects tire pressure, and a first count for counting the number of times the tire condition data is received. The process, the process of receiving the data of the number of operations of the tire condition measuring unit or the number of cycles corresponding to the standby time together with the tire condition data, and the second counting process of counting the number of operations of the tire condition measuring unit or , The tire condition monitoring system is based on the third count process for counting the cycle corresponding to the standby time, the number of operations counted from the first count process to the third count process, and the discharge capacity in each operation. The gist is to have an estimation process for estimating the discharged capacity of the driven battery.

As a result, it is possible to accurately calculate the main discharge capacity of the battery that drives the tire condition measuring unit without being affected by the fluctuation of the measurement cycle.

Further, a more accurate discharge capacity can be estimated by considering the discharge capacity and the standby power of the tire condition measuring unit.

Further, it is possible to estimate the remaining battery level with high accuracy based on the usage status of the tire condition measuring unit.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a tire condition monitoring system, a battery discharge capacity estimation program, and a discharge capacity estimation method capable of more accurately predicting the life of a battery used in a tire condition measuring unit.

It is a schematic block diagram which shows the schematic structure of the tire condition monitoring system which can execute the discharge capacity estimation process which concerns on Example. It is a functional block diagram which shows the functional structure of the tire condition monitoring system which can execute the discharge capacity estimation process which concerns on Example. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 1) which concerns on 1st Example. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 2) which concerns on 2nd Example. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 3) which concerns on 3rd Example. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 4th) which concerns on 4th Embodiment. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 5) which concerns on 5th Embodiment. It is a graph which shows the relationship between a battery temperature and a voltage. It is a flowchart which shows the processing procedure of the discharge capacity estimation processing (the 6th) which concerns on 6th Embodiment. It is a schematic block diagram which shows the modification of the tire condition monitoring system which can execute the discharge capacity estimation process which concerns on Example.

[About the tire condition monitoring system]
With reference to FIGS. 1 and 2, the tire condition monitoring system S1 capable of executing the discharge capacity estimation process (discharge capacity estimation program) according to the embodiment of the present invention (1st to 6th examples, etc.) explain.

In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the ratio of each dimension is different from the actual one.

Therefore, the specific dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that parts having different dimensional relationships and ratios are included between the drawings.

(Outline configuration of tire condition monitoring system)
The schematic configuration of the tire condition monitoring system S1 will be described with reference to the schematic configuration diagram of FIG.

The tire condition monitoring system S1 is provided on the side of a pneumatic tire (hereinafter, simply referred to as a tire) 10 and is acquired by a sensor unit SU as a tire condition measuring unit for measuring the condition of the tire 10 and a sensor unit SU. It is composed of a processing device (vehicle-mounted device (ECU), etc.) 300 that processes various information.

FIG. 1 shows a cross-sectional shape of a tire 10 assembled to a rim wheel 90 along the tire width direction.

Further, the tread portion 20 is a portion that comes into contact with the road surface when the tire 10 mounted on a vehicle (not shown) rolls on the road surface. The tread portion 20 is formed with a tread pattern according to the type of vehicle and the required performance.

A sensor unit SU for detecting the temperature information and the internal pressure information of the tire 10 is provided on the inner surface 10a of the tire 10 to which the tire condition monitoring system S1 can be applied.

In the configuration example shown in FIG. 1, the sensor unit SU is provided on the inner surface 10a facing the tread portion 20. More specifically, the sensor unit SU is attached to the surface of an inner liner (not shown) that prevents the leakage of gas such as air filled in the internal space of the pneumatic tire 10 assembled to the rim wheel 90.

The sensor unit SU is not limited to the inner surface 10a facing the tread portion 20, but may be provided on the inner surface of the tire 10 on the sidewall 30 side.

The sensor unit SU is preferably provided on each tire 10 mounted on the vehicle. This is because it is desirable to monitor the leak condition of each tire 10 in order to ensure the safety of the vehicle.

Further, the sensor unit SU does not necessarily have to be attached to the inner surface of the tire 10, and for example, a part or all of the sensor unit SU may be embedded inside the tire 10.

(Functional configuration of tire condition monitoring system)
As shown in the functional block diagram of FIG. 2, the sensor unit SU as a tire condition measuring unit for measuring the condition of the tire 10 detects the internal pressure sensor SN1 for detecting the internal pressure (air pressure) of the tire 10 and the temperature of the tire 10. It includes a temperature sensor SN2 and an acceleration sensor SN3 that detects the acceleration of rotation of the tire 10. It also includes a voltage detection unit 104 that detects the voltage of the battery 150, which will be described later.

Further, the sensor unit SU is composed of a microcomputer or the like, and includes a control unit 101 that controls the operation of the internal pressure sensor SN1, the temperature sensor SN2, the acceleration sensor SN3, the voltage detection unit 104, the transmission unit 103 described later, and the like.

Further, a storage unit 102 including an internal pressure sensor SN1, a temperature sensor SN2, an acceleration sensor SN3, a flash memory for temporarily storing detection data of the voltage detection unit 104, and the like is provided.

Further, a transmission unit 103 for transmitting detection data and the like to the processing device 300 via the wireless line N1 is provided.

Further, a battery 150 composed of a button-type lithium battery or the like that supplies power to each unit such as the control unit 101 is integrally provided.

The entire sensor unit SU is molded with a resin layer 200 such as plastic. As a result, the weather resistance and durability of the sensor unit SU are ensured.

Although not shown, a pressure introduction hole is formed in the resin layer 200 in order to detect the pressure by the internal pressure sensor SN1. Further, the transmission unit 103 may be provided with an RF antenna.

Then, under the control of the control unit 101, the tire state data such as the internal pressure data, the temperature data, and the acceleration data of the tire 10 are acquired by the internal pressure sensor SN1, the temperature sensor SN2, and the acceleration sensor SN3 at a predetermined cycle.

Further, the voltage detection unit 104 acquires data on the voltage of the battery 150 at a predetermined cycle under the control of the control unit 101.

Further, the transmission unit 103 transmits the acquired tire state data and the like to the processing device 300 via the wireless line N1.

On the other hand, the processing device 300 includes a data acquisition unit 301 that acquires tire state data and the like transmitted from the sensor unit SU side.

Further, the storage unit 302 including a flash memory or the like for storing the acquired tire state data, the program data for the discharge capacity estimation process, and the like is provided.

It also includes a discharge capacity estimation unit 303 composed of a microcomputer or the like that estimates the discharge capacity of the battery 150 discharged based on the detection data of the voltage detection unit 104 or the like.

Further, the communication unit 304 is provided to transmit tire state data, data related to the discharge capacity estimated by the discharge capacity estimation unit 303, and the like to an external device 500 such as a management server via the wireless line N2.

[Discharge capacity estimation process]
The discharge capacity estimation process (No. 1 to No. 6) according to the first to sixth embodiments that can be executed by the processing device 300 of the tire condition monitoring system S1 described above will be described with reference to the flowcharts of FIGS. 3 to 8. ..

(First Example)
The processing procedure of the discharge capacity estimation processing (No. 1) according to the first embodiment will be described with reference to the flowchart of FIG.

This discharge capacity estimation process (No. 1) estimates the discharge capacity (battery consumption) of the battery 150 based on the number of first to third counts described later, and corresponds to a so-called feed-forward method process. ..

When this process is started, first, in step S10, the tire state data transmitted from the sensor unit SU side is acquired by the data acquisition unit 301, and the process proceeds to step S11.

In step S11, the first count step of counting the number of times the tire condition data is received is executed.

The non-volatile memory in the CPU of the control unit 101 included in the sensor unit SU counts up the number of transmissions from the sensor unit SU side, adds the count number to the communication packet, and receives the tire state data based on the information. You can count the number of times you have done it.

Next, in step S12, data on the number of operations of the sensor unit SU as the tire condition measuring unit for measuring the condition of the tire 10 or the number of cycles corresponding to the standby time of the sensor unit SU is received together with the tire condition data.

The non-volatile memory in the CPU of the control unit 101 included in the sensor unit SU counts up the number of waits, adds the count to the communication packet, and based on the information, a cycle corresponding to the wait time of the sensor unit SU. You can get a number of data.

Next, in step S13, a second count step for counting the number of operations of the sensor unit SU or a third count step for counting the cycle corresponding to the standby time is executed, and the process proceeds to step S14.

In the third count step, the count number of the timer of the CPU (arithmetic unit) included in the transmission unit 103 of the sensor unit SU can be counted as the number of cycles corresponding to the standby time. This allows the wait time to be accurately counted without additional equipment.

In step S14, the discharge capacity discharged by the battery 150 driving the sensor unit SU of the tire condition monitoring system S1 is calculated based on the number of operations counted in the first count step to the third count step and the discharge capacity in each operation. The first guessing step of guessing is executed to end the process.

In the above-mentioned processing, the area corresponding to the current × time is measured at the time of designing or manufacturing the sensor unit SU with the area corresponding to the current × time as the value in one cycle unit both in the standby state and the operating time of the sensor unit SU, and the operation of the sensor unit SU is performed. It is a process of counting the number of times and the number of times of waiting, respectively, and estimating the battery 150 consumption (for example, in mAh units) based on the integrated value with the unit discharge capacity of one cycle.

According to this process, the main discharge capacity of the battery 150 that drives the tire condition monitoring system S1 can be accurately calculated without being affected by the fluctuation of the measurement cycle.

Further, a more accurate discharge capacity can be estimated by considering the discharge capacity of the sensor unit SU and the standby power.

Further, it is possible to estimate the remaining battery level with high accuracy based on the usage status of the sensor unit SU.

When the acceleration of the tire 10 detected by the acceleration sensor SN3 of the sensor unit SU is equal to or less than a predetermined value, the operation of each part of the sensor unit SU can be stopped in order to save power.

(Second Example)
The processing procedure of the discharge capacity estimation processing (No. 2) according to the second embodiment will be described with reference to the flowchart of FIG.

In this discharge capacity estimation process (No. 2), the estimation results of the first estimation step and the second estimation step, which will be described later, are compared, and the larger value is used as the estimation value.

Further, the discharge capacity estimation process (No. 2) is a process belonging to the so-called feedback method of estimating the consumption of the battery 150 based on the voltage data and the temperature data of the battery 150.

When this process is started, first, in the subroutine SB1, the processes of steps S10 to S4 in the flowchart of FIG. 3 described above are executed, and the process proceeds to step S15.

In step S15, the voltage data and temperature data of the battery 150 are received together with the tire state data, and the process proceeds to step S16.

In step S16, a second estimation step of estimating the discharge capacity discharged by the battery 150 is executed based on the voltage data and the temperature data, and the process proceeds to step S17.

In step S17, the estimation results of the first estimation step and the second estimation step are compared, and the process ends with the larger value as the estimated value of the discharge capacity.

As a result, the remaining battery level of the battery 150 can be estimated with high accuracy, particularly at the end of use.

(Third Example)
The processing procedure of the discharge capacity estimation processing (No. 3) according to the third embodiment will be described with reference to the flowchart of FIG.

This discharge capacity estimation process (No. 3) predicts the future consumption of the battery 150 based on the number ratio of the first count step to the third count step.

When this process is started, first, in the subroutine SB1, the processes of steps S10 to S4 in the flowchart of FIG. 3 described above are executed, and the process proceeds to step S18.

In step S18, the ratio of the number of operations of the sensor unit SU counted in the first count step to the third count step is calculated, and the process proceeds to step S19.

In step S19, a prediction step for predicting a change in the discharge capacity of the battery 150 to be discharged in the future is executed based on the ratio and the discharge capacity of each operation of the sensor unit SU to end the process.

As a result, future changes in the remaining amount of the battery 150 can be predicted with high accuracy based on the usage status of the sensor unit SU.

(Fourth Example)
The processing procedure of the discharge capacity estimation processing (No. 4) according to the fourth embodiment will be described with reference to the flowchart of FIG.

In this discharge capacity estimation process (No. 4), the time when the life of the battery 150 expires is determined based on the predicted value and the operating limit voltage of the transmission unit.

When this process is started, first, in the subroutine SB2, the above-mentioned subroutine SB1 and steps S18 and S19 in the flowchart of FIG. 5 are executed to move to step S20.

In step S20, a determination step for determining when the life of the battery 150 expires is executed based on the operating limit voltage of the transmission unit 103 driven by the battery 150 and the prediction result of the prediction step, and the process ends.

This makes it possible to accurately predict the replacement time of the sensor unit SU.

(Fifth Example)
The processing procedure of the discharge capacity estimation process (No. 5) according to the fifth embodiment will be described with reference to the flowchart of FIG. 7 and the graph of FIG.

When this process is started, in step S121, the voltage data and temperature data of the battery 150 are received together with the tire state data, and the process proceeds to step S122.

In step S122, in the second estimation step, a plurality of correspondence tables and graphs relating to the discharged discharge time for the voltage data for each of a plurality of temperatures are calculated in advance, and the process proceeds to step S123.

Here, FIG. 8 shows an example of a graph created for the battery 150 based on the calculation result in step S122, with the voltage on the vertical axis and the discharge time on the horizontal axis to show the relationship between the battery temperature and the voltage. ..

In FIG. 8, the discharge characteristics of the battery 150 at temperatures t1 to t4 are plotted.

It is generally known that the battery is activated when the temperature rises.

Then, in step S123, the correspondence table or graph corresponding to the received temperature data is selected, and the process proceeds to step S124.

In step S124, the received voltage data is compared with the voltage data of the selected correspondence table or graph data, the discharge capacity discharged by the battery 150 is estimated, and the process is terminated.

As a result, the remaining battery level of the battery 150 can be estimated with high accuracy, particularly at the end of use.

(6th Example)
The processing procedure of the discharge capacity estimation processing (No. 6) according to the sixth embodiment will be described with reference to the flowchart of FIG.

When this process is started, in the flowchart SB2, the above-mentioned subroutine SB1 and steps S18 and 19 of the flowchart of FIG. 5 are executed to move to step S23.

In step S23, the predicted minimum temperature data is acquired from a predetermined meteorological data providing site or the like, and the process proceeds to step S24.

In step S24, the operation output voltage of the transmission unit 103 at the predicted minimum temperature at the time of the predicted discharge capacity change is predicted, and the process proceeds to step S25.

In step S25, it is determined whether or not the predicted transmission unit operation output voltage is lower than the transmission unit operation limit voltage. If "No", the process ends, and if "Yes", the process proceeds to step S26. ..

In step S26, it is determined that the life of the battery 150 has expired, and the process is terminated.

As a result, it is possible to estimate the discharge capacity according to the season accompanied by the temperature change, and it is possible to avoid the situation where the sensor unit SU is not operated due to the insufficient remaining amount of the battery 150.

(Other examples)
The voltage data of the battery 150 received by the processing device 300 can be measured at the timing of transmitting the data from the transmission unit 103.

This makes it possible to easily calculate the output voltage at the time of determination even when the output voltage differs depending on the operation of the transmission unit 103.

Further, the above-mentioned predicted minimum temperature may be predicted from statistical data of temperature change. This makes it possible to estimate the discharge capacity based on highly accurate minimum temperature data.

Further, the predicted minimum temperature may be predicted from the statistical data in the corresponding area acquired from the current area of the vehicle based on the GPS data. This makes it possible to estimate the discharge capacity based on more accurate minimum temperature data.

Further, the relational expression regarding the discharge time for the voltage for each temperature in the second estimation step is set by acquiring in advance the one measured by the resistance value corresponding to the current at the time of voltage measurement of the transmission unit 103. May be good.

(Modification example)
The tire condition monitoring system S1a according to the modified example will be described with reference to FIG. 10.

FIG. 10 is a schematic configuration diagram of the tire condition monitoring system S1a according to the modified example.

As shown in FIG. 10, in the tire condition monitoring system S1a, the processing device 300 (ECU or the like) mounted on each vehicle communicates wirelessly with the sensor unit SU mounted on the pneumatic tire 10 via the wireless line N1. At the same time, it is configured to communicate with an external wireless base station 400 via the wireless line N2.

Further, the wireless base station 400 is connected to the management server 500 provided on the cloud system.

Then, the processing device 300 of each vehicle transmits the temperature data acquired from the sensor unit SU, the internal pressure data, and the data of the estimation result of the discharge capacity of the battery 150 to the radio base station 400.

As a result, the management server 500 can grasp the state of the tire 10 of each vehicle and the consumption status of the battery 150 of each sensor unit SU, and take measures such as notifying the driver of each vehicle at an appropriate timing. be able to.

It should be noted that a part or all of the above-mentioned discharge capacity estimation process executed by the processing device 300 may be performed by the cloud system or the management server 500.

Although the battery discharge capacity estimation program and the discharge capacity estimation method according to the present invention have been described above based on the illustrated embodiment, the present invention is not limited to this, and the configurations of the respective parts have the same functions. It can be replaced with any configuration that has.

S1, S1a Tire condition monitoring system SU sensor unit (tire condition measurement unit)
SN1 Internal pressure sensor SN2 Temperature sensor SN3 Acceleration sensor 10 Pneumatic tire 101 Control unit 102 Storage unit 103 Transmission unit 104 Voltage detection unit 150 Battery 200 Resin layer 300 Processing device 301 Data acquisition unit 302 Storage unit 303 Discharge capacity estimation unit 304 Communication unit 500 External device (management server, etc.)

Claims (10)

A tire condition measuring unit located on the inner surface of a pneumatic tire and measuring tire condition data of the tire, and a tire condition measuring unit.
The battery that drives the tire condition measuring unit and
A data acquisition unit that acquires the tire condition data from the tire condition measurement unit,
A storage unit that stores the acquired tire condition data, and
A discharge capacity estimation unit that estimates the discharge capacity of the battery, and a discharge capacity estimation unit.
It is a tire condition monitoring system that has at least
The data acquisition unit
Data of the number of operations of the tire condition measuring unit or the number of cycles corresponding to the standby time is received together with the tire condition data.
The discharge capacity estimation unit is
The first count step of counting the number of times the tire condition data is received is executed, and the tire condition data is counted.
A second count step for counting the number of operations of the tire condition measuring unit or a third count step for counting the cycle corresponding to the waiting time is executed.
A tire condition monitoring system that executes a first estimation step of estimating the discharge capacity discharged by the battery based on the number of operations counted from the first count step to the third count step and the discharge capacity in each operation. The step of receiving tire condition data from the tire condition measuring unit that measures the tire condition, and
The first count step for counting the number of times the tire condition data is received, and
A step of receiving data on the number of operations of the tire condition measuring unit or the number of cycles corresponding to the standby time together with the tire condition data, and
A second count step for counting the number of operations of the tire condition measuring unit, or a third count step for counting the cycle corresponding to the waiting time.
Based on the number of operations counted from the first count step to the third count step and the discharge capacity in each operation, the first estimation step of estimating the discharge capacity discharged by the battery driving the tire condition measuring unit. ,
Have,
A battery discharge capacity estimation program executed by a computer provided in a tire condition monitoring system using the tire condition measuring unit. A step of receiving the voltage data and temperature data of the battery together with the tire condition data,
A second estimation step for estimating the discharge capacity of the discharged battery based on the voltage data and the temperature data, and
The battery discharge capacity estimation program according to claim 2, further comprising a step of comparing the estimation results of the first estimation step and the second estimation step and using the larger value as the estimated value of the discharge capacity. The discharge capacity that the battery will discharge in the future based on the ratio of the number of operations of the tire condition measuring unit counted from the first count step to the third count step and the discharge capacity of each operation of the tire condition measuring unit. The battery discharge capacity estimation program according to claim 2 or 3, further comprising a prediction step for predicting a change in. 4. The tire condition measuring unit further includes a determination step for determining when the battery life is exhausted based on the operating limit voltage of the battery-driven transmission unit and the prediction result of the prediction step. Battery discharge capacity estimation program described in. In the second estimation step, the calculated data of the discharged discharge time with respect to the received voltage data for each temperature is compared with the received voltage data, and the discharge capacity discharged by the battery is estimated. The battery discharge capacity estimation program described in. With additional steps to get predicted minimum temperature data,
The determination step is
Predict the operating output voltage of the transmitter at the predicted minimum temperature at the time of the predicted discharge capacity change,
Compare the predicted transmitter operating output voltage with the transmitter operating limit voltage,
The battery discharge capacity estimation program according to claim 5, wherein when the predicted transmitter operating output voltage is lower than the transmitter operating limit voltage, it is determined that the life of the battery has expired. The third count step is
The battery discharge capacity estimation program according to claim 5, wherein the count number of the timer of the arithmetic unit included in the transmitter is counted as the number of cycles corresponding to the standby time. The battery discharge capacity estimation program according to claim 5, wherein the voltage data of the battery to be received is measured at the timing of transmitting the data from the transmission unit. The process of receiving tire condition data from the tire condition measuring unit that detects the tire pressure, and
The first counting process for counting the number of times the tire condition data is received and
The process of receiving the data of the number of operations of the tire condition measuring unit or the number of cycles corresponding to the standby time together with the tire condition data, and
A second counting process for counting the number of operations of the tire condition measuring unit, or a third counting process for counting the cycle corresponding to the waiting time.
A guessing process of estimating the discharged capacity of the battery driving the tire condition measuring unit based on the number of operations counted in the first count process to the third count process and the discharge capacity in each operation.
How to estimate the discharge capacity of a battery with.

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