Range estimation method

Abstract

To improve cruisable distance accuracy.SOLUTION: A cruising distance estimation method includes: a collection process in which a plurality of learning values corresponding to a plurality of fuel cell vehicles respectively are collected from the plurality of fuel cell vehicles; a generation process in which fuel consumption data, which indicates time change of fuel consumption, is generated on the basis of the plurality of fuel learning values; a calculation process in which when requested from one of the plurality of fuel cell vehicles, a correction value for correcting the latest fuel consumption learning value on the basis of the latest fuel consumption learning value of one fuel cell vehicle and the fuel consumption data; a transmission process in which the calculated correction value is transmitted to one fuel cell vehicle; and a correction process in which one fuel cell vehicle corrects the latest fuel consumption learning value by use of the correction value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the technical field of range estimation methods. [Background technology]

[0002] As a method of this kind, for example, a method has been proposed in which fuel efficiency is learned when a fuel cell vehicle is refueled, and a cruising range is calculated (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-118658 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, fuel efficiency is learned when refueling. If refueling is performed relatively infrequently, there are also relatively few opportunities for learning fuel efficiency, for example, through machine learning. This poses a technical problem in that the accuracy of the cruising range calculated using the learned fuel efficiency decreases.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a cruising range estimation method that can improve the accuracy of the cruising range even when the frequency of refueling is relatively low. [Means for solving the problem]

[0006] A cruising range estimation method according to one aspect of the present invention includes: of the same model Multiple fuel cell vehicles a server device capable of communicating with the plurality of fuel cell vehicles; a collection step of collecting a plurality of fuel efficiency learned values ​​corresponding to the plurality of fuel cell vehicles from the The server device: The plurality of fuels expensea generation step of generating fuel efficiency data indicating a change in fuel efficiency over time based on the learned value; and The server device: a calculation step of calculating a correction value for correcting the latest fuel efficiency learned value based on the latest fuel efficiency learned value of the one fuel cell vehicle and the fuel efficiency data; The server device: The method includes a transmission step of transmitting the calculated correction value to the one fuel cell vehicle, and a correction step in which the one fuel cell vehicle corrects the latest fuel efficiency learning value using the correction value. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a block diagram showing a configuration of a server device according to the embodiment. [Figure 2] FIG. 10 is a diagram showing an example of a change in fuel efficiency over time. [Figure 3] 4 is a flowchart showing a first operation according to the embodiment. [Figure 4] 10 is a flowchart showing a second operation according to the embodiment. [Figure 5] 10 is a flowchart showing a third operation according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the range estimation method will be described with reference to Figs. 1 to 5. A configuration to which the range estimation method is applied will be described with reference to Fig. 1. In Fig. 1, a server device 10 includes a calculation device 11, a storage device 12, and a communication device 13. The calculation device 10 has a collection unit 1111, a generation unit 112, a calculation unit 113, and a transmission unit 114. The collection unit 1111, the generation unit 112, the calculation unit 113, and the transmission unit 114 may be logically configured processing blocks. The collection unit 1111, the generation unit 112, the calculation unit 113, and the transmission unit 114 may be physically realized processing circuits. The server device 10 is configured to be able to communicate with a plurality of fuel cell vehicles V via the communication device 13.

[0009] The fuel cell vehicles V are so-called connected cars. The fuel cell vehicles V are fuel cell vehicles V1, V2, V3, V4, ..., V n Fuel cell vehicles V1, V2, V3, V4, ..., V n are fuel cell vehicles of the same model. The system configured by the server device 10 and the plurality of fuel cell vehicles V may be called a cruising distance estimation system.

[0010] Each of the multiple fuel cell vehicles V calculates a learned value of fuel efficiency of the vehicle based on actual driving results (e.g., actual driving distance, actual fuel consumption). The learned value of fuel efficiency will hereinafter be referred to as the "learned fuel efficiency value" as appropriate. Each of the multiple fuel cell vehicles V calculates a learned fuel efficiency value at a predetermined timing (e.g., when refueling). Each of the multiple fuel cell vehicles V updates its learned fuel efficiency value when a new learned fuel efficiency value is calculated. Each of the multiple fuel cell vehicles V estimates the cruising range (or possible cruising distance) of the vehicle based on the learned fuel efficiency value and the remaining amount of fuel. Various existing methods can be applied to the calculation of the learned fuel efficiency value. Therefore, a detailed description of the calculation method of the learned fuel efficiency value will be omitted.

[0011] The usage frequency of each of the multiple fuel cell vehicles V is different. Therefore, the update frequency of the fuel efficiency learning value of each of the multiple fuel cell vehicles V is also different. Here, the fuel efficiency of a fuel cell vehicle is relatively greatly affected by the outside temperature. When the outside temperature is relatively low, more fuel is consumed than when the outside temperature is relatively high due to at least one of control to prevent generated water from freezing and use of heating. Therefore, when the update frequency of the fuel efficiency learning value is relatively low, there is a possibility that the fuel efficiency learning value and the actual fuel efficiency will differ relatively greatly. As a result, there is a possibility that the error between the cruising range estimated based on the fuel efficiency learning value and the actual cruising range will be relatively large.

[0012] The server device 10 calculates a correction value for correcting the learned fuel efficiency value through the operation described below. The collection unit 111 of the server device 10 collects, from the plurality of fuel cell vehicles V, a plurality of learned fuel efficiency values ​​corresponding to the plurality of fuel cell vehicles V, respectively. The collection unit 111 assigns time information (e.g., a timestamp) indicating the date of collection to each of the plurality of learned fuel efficiency values. The collection unit 111 stores the plurality of learned fuel efficiency values ​​in the storage device 12.

[0013] The generation unit 112 extracts learned fuel efficiency values ​​of the same date from among the multiple learned fuel efficiency values ​​stored in the storage device 12. The generation unit 112 calculates the average value of the extracted learned fuel efficiency values. The generation unit 112 associates the calculated average value with the date of the extracted learned fuel efficiency value and stores it in the storage device 12. The average value of the learned fuel efficiency values ​​will hereinafter be referred to as "average learned fuel efficiency" as appropriate. The generation unit 112 generates time series data of the average learned fuel efficiency by repeatedly performing the same process. When the generated time series data is represented in a graph, the change over time in the average learned fuel efficiency appears as shown in Figure 2.

[0014] When one of the multiple fuel cell vehicles V (e.g., fuel cell vehicle V1) estimates its cruising range, the one fuel cell vehicle transmits the date on which its own fuel efficiency learning value was last updated to the server device 10. The calculation unit 113 of the server device 10 identifies the average learned fuel efficiency F1 corresponding to the date (e.g., time t1) transmitted from the one fuel cell vehicle from the time series data (see FIG. 2). The calculation unit 113 identifies the average learned fuel efficiency F2 corresponding to the most recent time (e.g., time t2) in the time series data. The calculation unit 113 calculates a correction value by comparing the average learned fuel efficiency F1 and the average learned fuel efficiency F2. When the average learned fuel efficiency F2 is X% smaller than the average learned fuel efficiency F1, the correction value may be expressed as (1-X / 100).

[0015] The transmitting unit 114 of the server device 10 transmits the correction value to the one fuel cell vehicle via the communication device 13. The one fuel cell vehicle corrects its own learned fuel efficiency value by multiplying the correction value transmitted from the server device 10 by the one fuel cell vehicle's learned fuel efficiency value. The one fuel cell vehicle estimates the cruising range using the corrected learned fuel efficiency value. Examples of cases in which the one fuel cell vehicle estimates the cruising range include when displaying the remaining cruising range on an instrument panel and when a navigation device determines whether or not the destination can be reached.

[0016] The operation of each of the plurality of fuel cell vehicles V and the server device 10 will be further described with reference to the flowcharts of Figures 3 to 5. In Figure 3, when each of the plurality of fuel cell vehicles V updates its learned fuel efficiency value (step S111), it transmits data indicating the learned fuel efficiency value to the server device 10 (step S112). In parallel with the processing of step S112, each of the plurality of fuel cell vehicles V updates a record indicating the date on which the learned fuel efficiency value was updated (step S113). Note that the record indicating the date on which the learned fuel efficiency value was updated may be stored in the memory of each of the plurality of fuel cell vehicles V.

[0017] The collection unit 111 of the server device 10 receives data indicating the learned fuel efficiency value from each of the multiple fuel cell vehicles V (step S121). The collection unit 111 assigns time information indicating the date of reception to the received learned fuel efficiency value (step S122), and stores the data in the storage device 12 (step S123). Note that the delay in communication between each of the multiple fuel cell vehicles V and the server device 10 is sufficiently small. Therefore, the date on which the learned fuel efficiency value of each of the multiple fuel cell vehicles V was updated is the same as the date indicated by the time information assigned to the learned fuel efficiency value by the server device 10.

[0018] 4, the generation unit 112 of the server device 10 retrieves from the storage device 12 a plurality of learned fuel efficiency values ​​to which time information indicating the date of the previous day has been added (step S201). The generation unit 112 calculates the average value (i.e., the average learned fuel efficiency) of the plurality of learned fuel efficiency values ​​retrieved in the processing of step S201 (step S202). The generation unit 112 adds and stores the calculated average learned fuel efficiency to the end of the time-series data of the average learned fuel efficiency (step S203). At this time, the average learned fuel efficiency calculated in the processing of step S202 is associated with the date of the previous day. The generation unit 112 performs the operation shown in the flowchart of FIG. 4 every day. Note that the server device 10 may delete from the storage device 12 a plurality of learned fuel efficiency values ​​used to calculate the average learned fuel efficiency. This configuration can save the storage capacity of the storage device 12.

[0019] When each of the multiple fuel cell vehicles V estimates its cruising range, each of the multiple fuel cell vehicles V retrieves a record indicating the date on which the fuel efficiency learning value was last updated (step S311). Each of the multiple fuel cell vehicles V transmits data indicating the retrieved date to the server device 10 (step S312). The calculation unit 113 of the server device 10 receives data indicating the date from each of the multiple fuel cell vehicles V (step S321). The calculation unit 113 extracts, from the time-series data of the average learned fuel efficiency, the average learned fuel efficiency corresponding to the date indicated by the data received in the processing of step S321 and the average learned fuel efficiency of the previous day (in other words, the most recent time) (step S322). The calculation unit 113 calculates a correction value based on the average learned fuel efficiency retrieved in the processing of step S322 (step S323).

[0020] The transmitting unit 114 of the server device 10 transmits data indicating the correction value calculated in the processing of step S323 to one of the plurality of fuel cell vehicles V via the communication device 13 (step S324). The one fuel cell vehicle corrects the fuel efficiency learned value based on the received correction value (step S313). Thereafter, the one fuel cell vehicle estimates the cruising range using the corrected fuel efficiency learned value (step S314).

[0021] Each of the multiple fuel cell vehicles V does not have to perform the operation shown in the flowchart of Fig. 5 every time it estimates the cruising distance. In this case, each of the multiple fuel cell vehicles V may store in memory the correction value transmitted from the server device 10. Each of the multiple fuel cell vehicles V may estimate the cruising distance by correcting the fuel efficiency learned value using the correction value stored in memory as long as the date does not change. Each of the multiple fuel cell vehicles V does not have to perform the operation shown in the flowchart of Fig. 5 if the elapsed time since the last update of the fuel efficiency learned value is less than a predetermined time (for example, 14 days).

[0022] (Technical Effects) The fuel efficiency learning value of each of the multiple fuel cell vehicles V is calculated based on the actual driving results. The actual amount of fuel consumed is affected by at least one of the following factors: the driver's personality, the condition of the roads frequently traveled, and the performance of the fuel cell. For this reason, it can be said that the fuel efficiency learning value of each of the multiple fuel cell vehicles V is a value that reflects the driver's personality, etc.

[0023] In contrast, the time-series data of the average learned fuel efficiency generated by the generation unit 112 of the server device 10 is composed of the average value of multiple learned fuel efficiency values. For this reason, it can be said that the average learned fuel efficiency does not reflect the individual characteristics of the driver. However, since the average learned fuel efficiency is calculated for each day, it can be said that the average learned fuel efficiency reflects the influence of factors that change from day to day. Of the factors that change from day to day, the factor that has the greatest influence on fuel efficiency is outside air temperature. Therefore, it can be said that the time-series data of the average learned fuel efficiency shown in FIG. 2 reflects fluctuations in outside air temperature. For this reason, it can be said that the correction value calculated based on the time-series data of the average learned fuel efficiency is a value for correcting the influence of outside air temperature on fuel efficiency.

[0024] As described above, the learned fuel economy value of each of the multiple fuel cell vehicles V is a value that reflects the individual characteristics of the driver, etc. In the present embodiment, the learned fuel economy value that reflects the individual characteristics of the driver, etc. is corrected by a correction value that corrects the effect of outside air temperature on fuel economy. Therefore, the corrected learned fuel economy value is a value that appropriately reflects the individual characteristics of the driver, etc. and the effect of outside air temperature on fuel economy. The accuracy of the cruising range estimated using the corrected learned fuel economy value is higher than when the learned fuel economy value before correction is used. Therefore, according to the present embodiment, even if the update frequency of the learned fuel economy value is relatively low, the accuracy of the estimated cruising range can be improved. In other words, according to the present embodiment, in a mode in which the learned fuel economy value is updated when fuel is replenished, the accuracy of the cruising range can be improved even if refueling is relatively infrequent.

[0025] (Variation) In the above-described embodiment, each of the plurality of fuel cell vehicles V stores the learned fuel efficiency value and the date on which the learned fuel efficiency value was updated. The learned fuel efficiency value of each of the plurality of fuel cell vehicles V and the date on which the learned fuel efficiency value was updated may be stored by the server device 10. Note that in the above-described embodiment, the date on which the learned fuel efficiency value was updated is stored. In addition to the date on which the learned fuel efficiency value was updated, the time or time zone on which the learned fuel efficiency value was updated may also be stored.

[0026] In the above-described embodiment, it is assumed that the multiple fuel cell vehicles V are all of the same model. However, in reality, there are various models of fuel cell vehicles. Therefore, a correspondence table between vehicle IDs and models may be generated or updated when a fuel cell vehicle is manufactured or modified. The correspondence table may be stored in the server device 10. When the server device 10 receives a learned fuel efficiency value from each of the multiple fuel cell vehicles V, it may assign information indicating the model to the received learned fuel efficiency value based on the vehicle ID and the correspondence table. The server device 10 may generate time-series data of average learned fuel efficiency for each model indicated by the information assigned to the learned fuel efficiency value.

[0027] For example, when a fuel cell vehicle is manufactured or repaired, a correspondence table between vehicle IDs and shipping regions or usage regions may be generated or updated. The correspondence table may be stored in the server device 10. When the server device 10 receives a learned fuel efficiency value from each of the multiple fuel cell vehicles V, it may assign information indicating the shipping region or usage region to the received learned fuel efficiency value based on the vehicle ID and the correspondence table. The server device 10 may generate time-series data of average learned fuel efficiency for each shipping region or usage region indicated by the information assigned to the learned fuel efficiency value. Note that, instead of the correspondence table, location information (e.g., GPS (Global Positioning System) information) indicating the location of each of the multiple fuel cell vehicles V may be assigned to the learned fuel efficiency value. In this case, the server device 10 may generate time-series data of average learned fuel efficiency for each region based on the location information assigned to the learned fuel efficiency value.

[0028] In the above-described embodiment, the average learned fuel efficiency is calculated taking into consideration the most recent update date (year, month, and day) of the learned fuel efficiency value. The average learned fuel efficiency may be calculated taking into consideration not only the most recent update date of the learned fuel efficiency value but also the update date immediately preceding the most recent update date. In this case, the server device 10 may classify the multiple learned fuel efficiency values ​​based on the period between the most recent update date and the update date immediately preceding the most recent update date (for example, classification into within one week, within one month, within three months, etc.). The server device 10 may generate time-series data of the average learned fuel efficiency for each period based on the classified learned fuel efficiency values. When the server device 10 calculates the correction value, the server device 10 may calculate the correction value based on time-series data of the average learned fuel efficiency corresponding to the period between the most recent update date of the learned fuel efficiency value of a fuel cell vehicle and the update date immediately preceding the most recent update date.

[0029] The server device 10 may have a predictor constructed by machine learning instead of the collection unit 111, the generation unit 112, and the calculation unit 113. The predictor may be a learning model that outputs a "rate of change in the learned fuel efficiency value" when the "date on which the learned fuel efficiency value was updated" and the "number of days elapsed from the date on which the learned fuel efficiency value was updated to the present" are input.

[0030] In the above-described embodiment, the average learned fuel efficiency is calculated based on the date on which the learned fuel efficiency value was updated, time-series data is generated, and a correction value is calculated. The outside air temperature may be used instead of the update date. That is, the learned fuel efficiency value may be associated with the average outside air temperature. The outside air temperature may be measured by a temperature sensor provided in each of the multiple fuel cell vehicles V. The server device 10 may calculate the average learned fuel efficiency for each average outside air temperature. When the server device 10 calculates the correction value, the server device 10 may calculate the correction value based on the average learned fuel efficiency corresponding to the average outside air temperature associated with the learned fuel efficiency value of one fuel cell vehicle and the average learned fuel efficiency corresponding to the current outside air temperature.

[0031] Aspects of the invention derived from the above-described embodiment and modifications will be described below.

[0032] A cruising range estimation method according to one aspect of the invention includes the steps of: collecting, from a plurality of fuel cell vehicles, a plurality of learned fuel efficiency values ​​corresponding to the plurality of fuel cell vehicles; generating fuel efficiency data indicating a change in fuel efficiency over time based on the plurality of learned fuel efficiency values; calculating, upon a request from one of the plurality of fuel cell vehicles, a correction value for correcting the latest learned fuel efficiency value based on the latest learned fuel efficiency value of the one fuel cell vehicle and the fuel efficiency data; transmitting the calculated correction value to the one fuel cell vehicle; and correcting, by the one fuel cell vehicle, the latest learned fuel efficiency value using the correction value. In the above-described embodiment, "time-series data of average learned fuel efficiency" corresponds to an example of "fuel efficiency data."

[0033] The method may include an estimation step in which the one fuel cell vehicle estimates a cruising range using the corrected latest fuel efficiency learned value.

[0034] In the calculation step, the correction value may be calculated based on a first fuel efficiency, which is a fuel efficiency corresponding to a date associated with the latest learned fuel efficiency value in the fuel efficiency data, and a second fuel efficiency, which is a current fuel efficiency in the fuel efficiency data. In the above-described embodiment, "average learned fuel efficiency F1" corresponds to an example of "first fuel efficiency," and "average learned fuel efficiency F2" corresponds to an example of "second fuel efficiency."

[0035] The correction value may be expressed as a ratio of the second fuel efficiency to the first fuel efficiency.

[0036] The present invention is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the claims and the gist or concept of the invention as can be read from the entire specification, and range estimation methods involving such modifications are also included in the technical scope of the present invention. [Explanation of symbols]

[0037] 10...server device, 11...arithmetic device, 12...storage device, 13...communication device, 111...collection unit, 112...generation unit, 113...calculation unit, 114...transmission unit

Claims

1. A method for collecting fuel efficiency learned values ​​from a plurality of fuel cell vehicles of the same model by a server device capable of communicating with the plurality of fuel cell vehicles; a generating step in which the server device generates fuel efficiency data indicating a change in fuel efficiency over time based on the plurality of fuel efficiency learned values; a calculation step in which, when a request is received from one of the plurality of fuel cell vehicles, the server device calculates a correction value for correcting the latest fuel efficiency learned value based on the latest fuel efficiency learned value of the one fuel cell vehicle and the fuel efficiency data; a transmission step in which the server device transmits the calculated correction value to the one fuel cell vehicle; a correction step in which the first fuel cell vehicle corrects the latest fuel economy learned value using the correction value; A cruising range estimation method comprising:

2. 2. The method for estimating a cruising distance according to claim 1, further comprising an estimation step in which the one fuel cell vehicle estimates a cruising distance using the corrected latest fuel efficiency learned value.

3. In the calculation step, the correction value is calculated based on a first fuel efficiency, which is a fuel efficiency corresponding to a date associated with the latest fuel efficiency learned value in the fuel efficiency data, and a second fuel efficiency, which is a current fuel efficiency in the fuel efficiency data. The method for estimating a cruising distance according to claim 1 .

4. The method for estimating a cruising distance according to claim 3 , wherein the correction value is expressed as a ratio of the second fuel efficiency to the first fuel efficiency.

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