JP7616110B2 - Life Expectancy Calculation Method - Google Patents

Description

The present invention relates to a lifespan calculation method, and more specifically, to a lifespan calculation method for calculating the lifespan of a calculation object of an on-board device on which the calculation object is mounted, the calculation object having a lifespan being calculated.

A method for calculating the predicted lifespan of a belt drive device that drives an endless belt has been proposed as a method for calculating the lifespan of an object to be calculated (see, for example, Patent Document 1). In this method, parameters related to the load applied to the parts during the time required to correct the belt position in the width direction of the endless belt to a set position are used as data, and the lifespan of the belt drive device is calculated based on this data.

JP 2017-167439 A

However, in a lifespan calculation method for calculating the lifespan of a calculation object, when a parameter related to a load is used as data and the lifespan is calculated based on this data, a discrepancy may occur between the calculated lifespan and the actual lifespan. In order to suppress such a discrepancy, a method of calculating the lifespan using multiple data acquired at predetermined time intervals or each time a device equipped with the calculation object moves a predetermined distance can be considered. However, the amount of discrepancy between the calculated lifespan and the actual lifespan varies depending on the number of data pieces. Therefore, it is desirable to calculate the lifespan of a calculation object more appropriately depending on the number of data pieces.

The main purpose of the lifespan calculation method of the present invention is to more accurately calculate the lifespan of the object being calculated based on the number of data items.

The life calculation method of the present invention employs the following measures to achieve the above-mentioned main objective.

The life calculation method of the present invention includes the steps of:
A life calculation method for calculating a life of a calculation object in a mounting device on which a calculation object to be calculated has been mounted, the method comprising the steps of:
a first step of storing, as data, a load-related parameter as a parameter related to a load applied to the calculation object, and a total moving distance or a total usage time of the mounted device from when the use of the mounted device is started until the load-related parameter is acquired, every time the mounted device moves a predetermined distance or every predetermined time;
a second step of, when the number of data items as the total number of the stored data items exceeds a predetermined number, calculating, for each of the plurality of stored data items, an expected total travel distance as an expected value of the total travel distance when an integrated value of the load-related parameter reaches a predetermined threshold value, or an expected total usage time as the total usage time when the integrated value reaches the predetermined threshold value, using the latest data among the plurality of stored data items through the predetermined number of previous data items, and calculating, as the lifespan, a value obtained by subtracting three times the standard deviation of the average value from an average value of the expected total travel distance or the expected total usage time for each of the data items; when the number of data items is equal to or less than the predetermined number, calculating, for each of the plurality of stored data items, the expected total travel distance or the expected total usage time, and calculating, as the lifespan, the average value;
The gist of the project is to provide the following:

In the life calculation method of the present invention, the load-related parameters as parameters related to the load applied to the calculation object and the total travel distance or total usage time of the mounted device from the start of use of the mounted device to the acquisition of the load-related parameters are stored as data every time the mounted device travels a predetermined distance or every predetermined time. When the total number of stored data exceeds a predetermined number, the most recent data to a predetermined number of past data are used to calculate, for each data, the expected total travel distance as the expected value of the total travel distance when the integrated value of the load-related parameters reaches a predetermined threshold, or the expected total usage time as the total usage time when the integrated value reaches a predetermined threshold, and the life is calculated by subtracting three times the standard deviation of the average value from the average value of the expected total travel distance or the expected total usage time for each data. Here, the "predetermined number" is the number at which the distribution of the average value of the expected total travel distance or the expected total usage time for each data significantly deviates from the normal distribution. When the number of data items exceeds a predetermined number and the distribution of the average value of the expected total travel distance or expected total usage time for each data item is close to a normal distribution and it is acceptable to use the standard deviation, the expected total travel distance or expected total usage time for each data item is subtracted from the average value by three times the standard deviation of the average value to calculate the lifespan, thereby allowing the calculated lifespan to have a margin of three times the standard deviation from the average value, and the lifespan of the calculation object to be calculated appropriately. When the number of data items is equal to or less than a predetermined number, the expected total travel distance or expected total usage time is calculated for each data item using all of the multiple data items stored, and the average value is calculated as the lifespan. This makes it possible to prevent the lifespan from being calculated as being too short. As a result, the lifespan of the calculation object can be calculated more appropriately according to the number of data items.

In the life calculation method of the present invention, the on-board device may be a vehicle, the calculation object may be a lubricating oil that lubricates the engine, and the load-related parameter may be the fuel injection amount in the engine for each temperature range of the lubricating oil. Also, the on-board device may be a vehicle, the calculation object may be an air cleaner of the engine, and the load-related parameter may be an integrated value of the intake air volume of the engine. Furthermore, the on-board device may be a water treatment device that treats water, the calculation object may be a filtration device that filters water, and the load-related parameter may be an integrated value of the water flow rate of the filtration device.

The life calculation system of the present invention comprises:
A lifespan calculation device that calculates a lifespan of a calculation object of a mounted device on which a calculation object to be calculated is mounted, comprising:
a storage processing unit that stores, as data, a load-related parameter as a parameter related to a load applied to the calculation object, and a total moving distance or a total usage time of the mounted device from when the use of the mounted device is started until the load-related parameter is acquired, every time the mounted device moves a predetermined distance or every predetermined time;
a life calculation unit that, when the number of data items as the total number of the data items stored in the storage processing unit exceeds a predetermined number, calculates, for each of the plurality of stored data items, an expected total travel distance as a predicted value of the total travel distance when an integrated value of the load-related parameter reaches a predetermined threshold value or an expected total usage time as the total usage time when the integrated value reaches the predetermined threshold value, using the latest data to the predetermined number of previous data items among the plurality of stored data items, and calculates, as the lifespan, a value obtained by subtracting three times the standard deviation of the average value from an average value of the expected total travel distance or the expected total usage time for each of the data items; and, when the number of data items is equal to or less than the predetermined number, calculates, for each of the plurality of stored data items, the expected total travel distance or the expected total usage time, and calculates, as the lifespan, the average value;
The gist of the invention is to provide the following:

In the life calculation system of the present invention, the load-related parameters as parameters related to the load applied to the calculation object and the total travel distance or total usage time of the mounted device from the start of use of the mounted device to the acquisition of the load-related parameters are stored as data every time the mounted device travels a predetermined distance or every predetermined time. When the total number of stored data exceeds a predetermined number, the system uses the stored data from the most recent data to a predetermined number of past data to calculate, for each data, the expected total travel distance as the expected value of the total travel distance when the integrated value of the load-related parameters reaches a predetermined threshold, or the expected total usage time as the total usage time when the integrated value reaches a predetermined threshold, and calculates the life as the average value of the expected total travel distance or the expected total usage time for each data minus three times the standard deviation of the average value. The "predetermined number" is a number determined in advance as the number of samples at which the distribution of the average value of the expected total travel distance or the expected total usage time for each data significantly deviates from the normal distribution. When the number of data items exceeds a predetermined number and the distribution of the average value of the expected total travel distance or expected total usage time for each data item is close to a normal distribution and it is acceptable to use the standard deviation, the expected total travel distance or expected total usage time for each data item is subtracted from the average value by three times the standard deviation of the average value to calculate the lifespan, thereby allowing the calculated lifespan to have a margin of three times the standard deviation from the average value, and the lifespan of the calculation object to be calculated appropriately. When the number of data items is less than a predetermined number and it is not possible to calculate a standard deviation with the required accuracy, the expected total travel distance or expected total usage time is calculated for each data item using all of the multiple stored data items, and the average value is calculated as the lifespan. Since the lifespan is calculated without using the standard deviation, the lifespan can be calculated more appropriately. As a result, the lifespan of the calculation object can be calculated more appropriately according to the number of data items.

1 is a diagram showing an outline of the configuration of a lifespan calculation system 10 that calculates the lifespan of a part (calculation object) mounted on a vehicle 30 by a lifespan calculation method according to an embodiment of the present invention. 10 is a flowchart showing an example of a lifespan calculation routine executed by the server 20. FIG. 13 is an explanatory diagram showing an example of how an expected total travel distance Dest(n) is set. 11 is an explanatory diagram showing an example of a state in which a life distance DLs is set when the number of data Nd is equal to or smaller than a predetermined number Ndref; FIG. FIG. 13 is an explanatory diagram showing an example of a state in which a life distance DLs is set when the number of data Nd exceeds a predetermined number Ndref. FIG. 11 is an explanatory diagram showing an example of a state in which a lifetime TLs is set when the number of data Nd exceeds a predetermined number Ndref;

Next, we will explain how to implement the present invention using examples.

Figure 1 is a schematic diagram showing the configuration of a lifespan calculation system 10 that calculates the lifespan of a part (calculation object) mounted on a vehicle 30 using a lifespan calculation method according to one embodiment of the present invention. The lifespan calculation system 10 includes a server 20, a vehicle 30, and a dealer PC 50.

The server 20 is configured as a well-known computer and includes a CPU, ROM, RAM, flash memory 22, a storage device (e.g., HDD, SSD, etc.), an input/output port, a communication port, etc. The server 20 is capable of communicating with the vehicle 30 and the dealer PC 50, which is a computer of the vehicle dealer, via wired or wireless communication.

The vehicle 30 is equipped with an engine 32 and an electronic control unit (hereinafter referred to as "ECU") 34 that controls the engine 32.

The engine 32 is configured as a multiple cylinder (e.g., 4-cylinder or 6-cylinder) internal combustion engine that uses gasoline or diesel as fuel and outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust. The engine 32 draws air cleaned by the air cleaner 32a into the intake pipe, passes it through a throttle valve, and then draws it into the combustion chamber via the intake valve. In addition, fuel is injected from a fuel injection valve during the intake stroke and compression stroke, and explosive combustion is caused by an electric spark from an ignition plug. The reciprocating motion of the piston, which is pushed down by the energy of the explosive combustion, is converted into the rotational motion of the crankshaft. Exhaust discharged from the combustion chamber into the exhaust pipe via the exhaust valve is discharged into the outside air via a purification device.

The ECU 34 is configured as a well-known microcomputer and includes a CPU, ROM, RAM, flash memory, input/output ports, and communication ports. Signals from various sensors are input to the ECU 34 through the input port. Examples of signals input to the ECU 34 include the intake air amount Qa from the air flow meter 36 attached upstream of the throttle valve of the intake pipe, and the total travel distance Dt from the odometer 38 that detects the total travel distance of the vehicle 30. Various control signals are output from the ECU 34 through the output port. Examples of signals output from the ECU 34 include a control signal to the throttle valve of the engine 32, a control signal to the fuel injection valve, and a control signal to the ignition plug. The ECU 34 inputs the intake air amount Qa detected by the air flow meter 34a at a predetermined time tref1 (for example, several msec), calculates the integrated intake air amount SUMqa by integrating the input intake air amount Qa, and stores it in the flash memory. The ECU 34 also measures the total usage time Tu, which is the total time the vehicle 30 has been used since it was shipped from the factory, and stores this in the flash memory.

The dealer PC 50 is configured as a well-known computer and includes a CPU, ROM, RAM, flash memory, a storage device (e.g., HDD, SSD, etc.), input/output ports, and communication ports. The dealer PC 50 can communicate with the server 20 via wired or wireless communication.

Next, the operation of the life calculation system 10 of the embodiment thus configured, particularly the operation when calculating the life of the air cleaner 32a, will be described. Each time the total travel distance Dt from the odometer 38 reaches a predetermined distance Dtref (e.g., 1500 km, 2000 km, 2500 km, etc.), the ECU 34 of the vehicle 30 transmits to the server 20 via communication the total travel distance (total movement distance) Dt from the odometer 38 and the accumulated intake air volume (load-related parameter) SUMqa, which is the accumulated intake air volume Qa detected by the air flow meter 34a as the load applied to the air cleaner 32a.

When the server 20 receives the total mileage Dt and the cumulative intake air volume SUMqa as data from the vehicle 30, it executes a life calculation routine. Figure 2 is a flowchart showing an example of a life calculation routine executed by the server 20. When this routine is executed, the server 20 first inputs the cumulative intake air volume SUMqa and the total mileage Dt received as data and stores them in the flash memory 22 of the server 20 (step S100).

Then, it is determined whether the total number of data Nd stored in the flash memory 22 exceeds a predetermined number Ndref (step S110). The predetermined number Ndref is the number at which the distribution of the average value Desta calculated from the estimated total travel distance Dest(1) to the estimated total travel distance Dest(Ndref), which will be described later, significantly deviates from the normal distribution, and is set to, for example, 10, 20, 30, etc.

When the number of data Nd is equal to or less than the predetermined number Ndref in step S110, it is determined that the distribution of the average value Desta is significantly different from the normal distribution and the standard deviation σ cannot be used appropriately, and the predicted total mileage Dest(1) to Dest(Nd) is set for each data item as a predicted value of the total mileage Dt when the integrated intake air amount SUMqa reaches the predetermined threshold value SUMref, using all of the data items stored in the flash memory 22 (step S120). Figure 3 is an explanatory diagram showing an example of how the predicted total mileage Dest(n) is set. In the figure, the white circles indicate each data item. As shown in the figure, the expected total mileage Dest(1) is set as the total mileage Dt at the intersection (black square S1 in the figure) of a straight line L1(1) connecting the origin (where the total mileage Dt is 0 and the accumulated intake air volume SUMqa is 0) and one of the data, and a straight line L2 where the accumulated intake air volume SUMqa is the predetermined threshold value SUMref. As with the expected total mileage Dest(1), the expected total mileage Dest(2) to Dest(Nd) are set as the total mileage Dt at the intersection of the straight line L2 and the straight lines L1(2) to L1(Nd) connecting the origin and each data.

Once the estimated total mileage Dest(1) to Dest(Nd) is set in this manner, the life distance DLs is calculated as the total mileage until the air cleaner 32a reaches the end of its life (step S130), and this routine ends. The life distance DLs is calculated as the average value Desta (=ΣDest(n)/Nd, where "n" is a natural number from 1 to Nd) obtained by dividing the sum of the estimated total mileage Dest(1) to Dest(Nd) set in step S120 by the number of data Nd. Figure 4 is an explanatory diagram showing an example of how the life distance DLs is set when the number of data Nd is equal to or less than a predetermined number Ndref. In the figure, white circles indicate each data, black squares indicate the intersections of lines L1(1)-L1(Nd) and line L2, and white squares indicate points where the total travel distance Dt is the average value Desta (life distance DLs) and the integrated intake air amount SUMqa is the predetermined threshold value SUMref. In this way, when the number of data Nd is small, the life distance DLs can be calculated more appropriately by calculating the average value Desta of the expected total travel distance Dest(1)-Dest(Nd) set in step S120 as the life distance DLs without using the standard deviation σ described below.

When the number of data Nd exceeds the predetermined number Ndref in step S110, the oldest data (the oldest accumulated intake air volume SUMqa and total travel distance Dt) is deleted from the multiple data stored in the flash memory 22 (step S140). By deleting the oldest data from the multiple data stored in the flash memory 22 in this manner, the flash memory 22 stores data from the latest data (the most recent accumulated intake air volume SUMqa and total travel distance Dt) to the predetermined number Ndref of data.

Then, in the same manner as in step 120, the expected total mileage Dest(1) to Dest(Ndref) is set for each of the predetermined number Ndref data stored in the flash memory 22 (step S150), the life distance DLs of the air cleaner 32a is calculated (step S160), and this routine is terminated. In step S160, the life distance DLs is calculated as the average value Desta (=ΣDest(n)/Ndref, where "n" is a natural number from 1 to Ndref) obtained by dividing the sum of the expected total mileage Dest(1) to Dest(Ndref) set in step S150 by the predetermined number Ndref, minus three times the standard deviation σ of the average value Desta (=Dest-3σ). Figure 5 is an explanatory diagram showing an example of how the life distance DLs is set when the number of data Nd exceeds the predetermined number Ndref. In the figure, white circles indicate each data, black squares indicate the intersections of the straight lines L1(1)-L2(Ndref) and L2, black squares indicate the points where the total travel distance Dt is the average value Desta and the cumulative intake air amount SUMqa is the predetermined threshold value SUMref, and white squares indicate the points where the total travel distance Dt is the average value Desta minus three times the standard deviation σ of the average value Desta (life distance DLs) and the cumulative intake air amount SUMqa is the predetermined threshold value SUMref. If the use of the air cleaner 32a exceeds its life, a malfunction may occur in the air cleaner 32a. Since it is not desirable for the air cleaner 32a to malfunction while the vehicle 30 is in use, it is desirable to calculate the life on the stricter (shorter) side. On the other hand, if the estimation is too short, the air cleaner 32a will be replaced or otherwise maintained early even though it has not yet reached the end of its life, and the efficiency of use of the air cleaner 32a will decrease. In the embodiment, when the number of data Nd exceeds the predetermined number Ndref, the distribution of the average value Desta is close to a normal distribution, so that the calculated life distance DLs can be calculated by subtracting three times the standard deviation σ from the average value Desta, thereby making the calculated life distance DLs more appropriate. In addition, since the life distance DLs is calculated using data from the latest data (the most recent integrated intake air volume SUMqa and the total travel distance Dt) to data up to the predetermined number Ndref of the past, the latest deterioration state of the air cleaner 32a and the latest driving manner of the vehicle 30 can be reflected in the calculated life distance DLs. In this way, the life distance DLs is calculated in different ways depending on whether the number of data Nd exceeds the predetermined number Ndref, so that the life distance DLs can be calculated appropriately according to the number of data Nd.

According to the life calculation method of the embodiment described above, the cumulative intake air volume SUMqa and the total mileage Dt are input and stored as data in the flash memory 22 of the server 20 each time the total mileage Dt from the odometer 38 of the vehicle 30 reaches a predetermined distance Dtref, and when the number of pieces of data Nd stored in the flash memory 22 exceeds the predetermined number Ndref, the predicted total mileage Dest(1) to Dest(Ndref) is set (calculated) for each piece of data using the most recent data up to the predetermined number Ndref of data among the multiple pieces of data stored, The life distance DLs is calculated by subtracting three times the standard deviation σ of the average value Desta from the average value Desta of the estimated total travel distance Dest(1) to Dest(Ndref), and when the number of data Nd is equal to or less than the predetermined number Ndref, the estimated total travel distance Dest(1) to Dest(Nd) is set (calculated) for each data using all of the stored data, and the average value Desta of the calculated estimated total travel distance Dest(1) to Dest(Nd) is calculated as the life distance DLs, so that the life distance DLs can be calculated appropriately according to the number of data Nd.

In the life calculation method of the embodiment, the life distance DLs of the air cleaner 32a is calculated. However, the calculation of the life distance is not limited to the air cleaner 32a, and other parts constituting the engine 32 or the lubricating oil lubricating the engine 32 may be the calculation of the life distance. When calculating the life distance DLs of the lubricating oil, in step S100, instead of the cumulative intake air volume SUMqa and the total mileage Dt, the deterioration degree Doil of the lubricating oil and the total mileage Dt are input as data, and in steps S120 and S150, the predicted total mileage Dest(1) to Dest(n) (where "n" is the value Nd in step S120 and the value Ndref in step S150) is set as the predicted value of the total mileage Dt when the deterioration degree Doil reaches the predetermined threshold Doilref from the multiple data stored in the flash memory 22. The degree of deterioration Doil is a load-related parameter related to the load applied to the lubricating oil, and is higher when the temperature of the lubricating oil is low compared to when the temperature of the lubricating oil is high, and is higher when there is a lot of mixed fuel such as gasoline or diesel compared to when there is little mixed fuel. Therefore, the degree of deterioration Doil is calculated by the ECU 34 of the vehicle 30 by multiplying the temperature range of the lubricating oil and the average fuel injection amount in each temperature range by a coefficient (when the temperature of the lubricating oil is low, it is higher than when the temperature of the lubricating oil is high, and when there is a lot of mixed fuel such as gasoline or diesel compared to when there is little mixed fuel). This makes it possible to calculate the life distance DLs of the lubricating oil.

In the life calculation method of the embodiment, in steps S130 and S160, a life distance DLs is calculated as the total driving distance until the air cleaner 32a reaches the end of its life. However, instead of the life distance DLs, a life TLs may be calculated as the time required for the air cleaner 32a to reach the end of its life from when the vehicle 30 is shipped from the factory. In this case, the ECU 34 of the vehicle 30 calculates the accumulated intake air volume SUMqa and the total usage time Tu (total usage time of the air cleaner 32a) as the accumulated value of the time the vehicle 30 has been used for each predetermined time or distance. In the server 20, in step S100 of the life calculation routine illustrated in FIG. 2, instead of the accumulated intake air volume SUMqa and the total travel distance Dt, the accumulated intake air volume SUMqa and the total usage time Tu are input as data from the vehicle 30, and in steps S120 and S150, using a plurality of data stored in the flash memory 22, the predicted total usage times Tust(1) to Tust(n) (where "n" is the value Nd in step S120 and the value Ndref in step S150) are set as predicted values of the total usage time Tu when the accumulated intake air volume SUMqa reaches the predetermined threshold value SUMref for each data, and in steps S130 and S160, the predicted total usage times Tust(1) to Tust(n) are used to calculate the life TLs instead of the predicted total travel distance Dest(1) to Dest(n).

In the life calculation method of the embodiment, the life distance DLs is calculated as the life of the air cleaner 32a mounted on the vehicle 30. However, the parts for which the life is calculated are not limited to those mounted on the vehicle 30, and various parts and oils mounted on ships, trains, and industrial machines may also be used for calculating the life. For example, when calculating the life TLs of a filtration device that is mounted on a water treatment device for treating water and filters water, the water treatment device transmits, as data to the server 20 at predetermined intervals, the integrated flow rate SUMf as the integrated value of the flow rate of the inflowing water and the total operating time To as the integrated value of the operating time since the water treatment device first started operating. In the server 20, in step S100 of the life calculation routine illustrated in FIG. 2, instead of the accumulated intake air volume SUMqa and the total mileage Dt, the accumulated flow rate SUMf and the total operating time To are input as data from the water treatment device, and in steps S120 and S150, using multiple data stored in the flash memory 22, predicted total operating times Toest(1) to Toest(n) (where "n" is the value Nd in step S120 and the value Ndref in step S150) are set as predicted values of the total operating time To when the accumulated flow rate SUMf reaches a predetermined threshold value SUMfref for each data, and in steps S130 and S160, the predicted total operating times Toest(1) to Toest(n) may be used to calculate the life TLs instead of the predicted total mileage Dest(1) to Dest(n). 6 is an explanatory diagram showing an example of a state in which the lifetime TLs is set when the number of data Nd exceeds a predetermined number Ndref. It is an explanatory diagram showing an example of a relationship between each data stored in the flash memory 22 and the lifetime TLs when the number of data Nd exceeds the predetermined number Ndref. In the figure, white circles indicate each piece of data, black squares indicate the intersection of line L1(1)-L1(Ndref) with line L2, and white squares indicate the point where the total operating time To is the average value Toesta (=ΣToest(n)/Ndref, where "n" is a natural number between 1 and Ndref) of the predicted total operating times Toest(1)-Toest(Ndref) minus three times the standard deviation σ of the average value Toesta (=Toesta-3σ, lifespan TLs) and the integrated intake air volume SUMfqa is the specified threshold value SUMfref.

In the embodiment, the server 20 executes the life calculation routine. However, instead of the server 20, a cloud system configured using a cloud service provided by a cloud vendor may execute the life calculation routine. The vehicle 30 may also execute the life calculation routine. Furthermore, multiple computers (e.g., the ECU 34 of the vehicle 30 and the server 20) may share and execute each process of the life calculation routine.

In the embodiment, the present invention is described as a lifespan calculation method, but the present invention may also be in the form of a lifespan calculation system.

The following describes the relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem. In the embodiment, the process of transmitting the total travel distance Dt from the odometer 38 and the integrated intake air amount SUMqa, which is the integrated intake air amount Qa detected by the air flow meter 34a, to the server 20 via communication each time the total travel distance Dt from the odometer 38 reaches a predetermined distance Dtref, executed by the ECU 34 of the vehicle 30, and the process of step S100 of the life calculation routine illustrated in FIG. 2 correspond to the "first step", and the process of steps S110 to S160 of the life calculation routine illustrated in FIG. 2 correspond to the "second step".

The correspondence between the main elements of the Examples and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the Examples are examples for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be based on the description in that column, and the Examples are merely a specific example of the invention described in the Means for Solving the Problem column.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms without departing from the scope of the invention.

The present invention can be used in industries such as manufacturing of life calculation systems that execute life calculation methods.

20 server, 22 flash memory, 30 vehicle, 32 engine, 32a air cleaner, 34 electronic control unit (ECU), 36 air flow meter, 38 odometer, 50 dealer PC.

Claims (1)

A life calculation method for calculating a life of a calculation object in a mounting device on which a calculation object to be calculated has been mounted, the method comprising the steps of:
a first step of storing, as data, a load-related parameter as a parameter related to a load applied to the calculation object, and a total moving distance or a total usage time of the mounted device from when the use of the mounted device is started until the load-related parameter is acquired, every time the mounted device moves a predetermined distance or every predetermined time;
a second step of calculating, when the total number of the stored data pieces exceeds a predetermined number, an expected total travel distance as an expected value of the total travel distance when an integrated value of the load-related parameter reaches a predetermined threshold value or an expected total usage time as the total usage time when the integrated value reaches the predetermined threshold value, for each of the stored data pieces using the latest data through the predetermined number of previous data pieces, and calculating, as the lifespan, a value obtained by subtracting three times the standard deviation of the average value from an average value of the expected total travel distance or the expected total usage time for each of the data pieces; and, when the number of the data pieces is equal to or less than the predetermined number, calculating, for each of the stored data pieces, the expected total travel distance or the expected total usage time, and calculating, as the lifespan, the average value;
A life calculation method comprising:

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