JP2011127459A - Driving assistance system, method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology which performs an appropriate guidance even if a factor that made fuel economy fluctuate is caused by another factor different from the factor. <P>SOLUTION: Traveling data with status values and fuel economy with respect to a plurality of status items regarding traveling of a vehicle correlated with each other are acquired, and the present traveling data and the past traveling data with different fuel economy from the present traveling data, are acquired from among the plurality of traveling data. The plurality of status items with the status values corresponding to the present traveling data fluctuated from the status values corresponding to the past traveling data are specified as factor items. When the factor with the fuel economy corresponding to the present traveling data fluctuated from the fuel economy corresponding to the past traveling data, is guided, the causal relation between the plurality of factor items is presented. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a driving support apparatus, method, and program for providing guidance for improving fuel efficiency.

  As a conventional technique for providing guidance for improving fuel efficiency, a technique has been proposed in which information on the driving operation of the driver and the driving state of the vehicle is collected, and factors that change the fuel efficiency are extracted from the driving operation and the driving state. (See Patent Document 1). In Patent Document 1, the driver improves the driving operation and the driving state corresponding to the factor that has changed the fuel consumption by performing guidance that presents the extracted factor to the driver.

JP 2008-163781 A

In the prior art, there has been a problem that appropriate guidance cannot be provided when a factor causing fluctuation in fuel consumption is caused by another factor different from the factor.
For example, when the sudden accelerator operation performed to recover the vehicle speed decreased due to the sudden brake operation inevitably caused by the interruption of another vehicle is a factor that deteriorated the fuel efficiency, Then, it is suggested that sudden brake operation and accelerator operation are factors that deteriorated fuel consumption. Even when the brake operation or accelerator operation other than when interrupted is appropriate, the driver will be conscious of improving the brake operation and accelerator operation, and there is a problem that the fuel consumption is worsened. It was. Furthermore, if the driver recognizes that sudden braking or accelerator operation is inevitable due to the interruption of another vehicle, the sudden braking operation or accelerator operation simply deteriorated fuel consumption. There was a problem that the driver would feel uncomfortable by presenting it as a factor.
The present invention has been made in view of the above problems, and it is an object of the present invention to provide a technique for providing appropriate guidance even when a factor that fluctuates fuel efficiency is caused by another factor different from the factor. And

  In order to achieve the above object, in the present invention, a plurality of factor items whose situation values fluctuate between past travel data and current travel data are specified. Then, when guiding the factor that the fuel efficiency corresponding to the current travel data fluctuates from the fuel efficiency corresponding to the past travel data, a causal relationship between a plurality of factor items is presented. By presenting the causal relationship, the driver can recognize that the fluctuation of the situation value for a certain factor item is caused depending on the fluctuation of the situation value for another factor item. Therefore, when there is a factor item whose status value fluctuates depending on the fluctuation of the status value of another factor item, it can be prevented that the fuel efficiency is fluctuated only by the fluctuation of the status value of the factor item. As described above, it is possible to provide appropriate guidance even when the factor causing the change in fuel consumption is caused by another factor different from the factor.

  Here, the travel data acquisition means only needs to acquire current and past travel data regarding the travel of the vehicle, and the travel period of the vehicle related to the current and past travel data is not particularly limited. For example, the travel period from the start to the end of travel may be the travel period, the travel period from the start to the end of travel in a certain travel section may be the travel period, or the travel in a certain travel situation is started. It is good also considering a period until it is complete | finished as a driving | running | working period. Furthermore, when there are a plurality of drivers of the vehicle, the traveling for the current and past traveling data may be limited to those performed by the same driver. In addition, certain traveling data may be acquired as past traveling data as it is, or an average of a plurality of traveling data may be acquired as past traveling data.

  The plurality of situation items specified as the factor items by the factor item specifying means may be situation items whose status values have fluctuated at least between past driving data and current driving data. Therefore, all the situation items whose situation values are changing may be specified as factor items, or only a part of the situation items whose situation values are changing may be specified as factor items. For example, only a situation item in which the degree of influence of the fluctuation of the situation value on the fuel efficiency is greater than a predetermined threshold may be specified as the factor item. Furthermore, a situation item in which the influence degree of the fluctuation of the situation value on the fuel consumption is relatively larger than other situation items may be specified as a factor item.

  The guidance means only needs to provide guidance that presents the causal relationship, and these guidance contents may be displayed on the display unit, or voice indicating the guidance may be output from the voice output unit. The causal relationship means a relationship in which one factor item depends on the other factor item when the status values of the pair of factor items fluctuate. Specifically, the mode in which the factor items themselves have a causal relationship, the mode in which the past or current status values for the factor items have a causal relationship, and the changes in the status values for the factor items from the past to the current time And a mode in which there is a causal relationship. In addition, there is a cause-and-effect relationship between the past or current situation value for one factor item itself and the other factor item, and the change from the past to the current situation value for one factor item itself and the other factor item. A mode with a causal relationship and a mode with a causal relationship between a past or current situation value for one factor item and a change of the situation value for the other factor item from the past to the current time can be mentioned. It should be noted that the timing at which the guiding means performs the guidance only needs to be at least after the timing at which the current travel data can be acquired, and can be immediately after the current travel data is acquired, for example, immediately after the engine is stopped. . For example, if the travel period for acquiring the current travel data is from the start to the end of acceleration travel, constant speed travel and deceleration travel, respectively, acceleration travel, constant speed travel and deceleration travel It is also possible to provide guidance every time it ends.

  The status item may be related to the running of the vehicle, and various items can be adopted. For example, the situation item may include an ambient environment situation item whose situation value depends on the surrounding environment of the vehicle, and a driving operation situation item whose situation value depends on the driving operation of the driver. In this case, it is desirable that the guidance means presents a causal relationship between the fluctuation of the situation value for the factor item belonging to the surrounding environment situation item and the fluctuation of the situation value for the factor item belonging to the driving operation situation item. As a result, the driver can recognize the causal relationship between the fluctuation of the status value of the surrounding environment status item and the driving operation status item as the factor item, and the fluctuation of the status value of the driving operation status item is The driver can recognize that it was inevitable depending on the fluctuation of the situation value. Therefore, a driver who recognizes that the driver has tried to improve the situation value of the driving operation condition item that does not need to be improved and deteriorated the fuel consumption, or the situation value of the driving operation condition item inevitably fluctuated. Can be made uncomfortable.

  As a preferable example of the past travel data, travel data having the largest number of situation items whose situation values match the current travel data among the travel data can be cited. By doing in this way, the more situation items with the same situation value, the more the number of candidate factor items whose situation values fluctuated between the past travel data and the current travel data can be narrowed down to a high accuracy. Factors can be specified. In addition, for a predetermined situation item, past traveling data having a situation value that matches each other may be acquired. For example, past traveling data that always matches the road type as the situation item may be acquired. In this case, when the current travel data relates to highway travel, it is desirable to acquire travel data having the largest number of situation items with the same situation value among travel data related to highway travel as past travel data. This is because the fuel consumption characteristics of highway traveling and ordinary road traveling differ greatly, and traveling data related to ordinary road traveling is not suitable as a comparison target for specifying the factor item.

  Further, the stronger the causal relationship of the change in the status value of the factor item, the stronger the degree to which the causal relationship is presented decisively. For example, if the causal relationship of the change in the status value of the factor item is weak, the causal relationship is limited to a level that suggests the causal relationship. As a result, when it cannot be determined that the situation value of one of the factor items having a causal relationship with the fluctuation of the situation value depends on the other situation value, there is a possibility that the fuel efficiency has fluctuated for both factor items. Can be recognized. Note that a strong causal relationship means that there is a high possibility that the status values of other factor items will vary depending on the variation of the status values of a certain factor item.

  Furthermore, the method of performing guidance for improving fuel consumption as in the present invention can also be applied as a program or method. In addition, the above-described device, program, and method may be realized as a single device or may be realized by using components shared with each part of the vehicle, and include various aspects. It is a waste. For example, it is possible to provide a navigation device, a method, and a program that include the above devices. Further, some changes may be made as appropriate, such as a part of software and a part of hardware. Furthermore, the invention is also established as a recording medium for a program for controlling the apparatus. Of course, the software recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future.

It is a block diagram of the navigation apparatus containing a driving assistance device. It is a flowchart which shows a driving assistance content determination process.

Here, embodiments of the present invention will be described in the following order.
(1) Configuration of navigation device:
(2) Driving support processing:
(3) Other embodiments:

(1) Configuration of navigation device:
FIG. 1 is a block diagram showing a configuration of a navigation device 10 including a driving support device according to the present invention. The navigation apparatus 10 includes a control unit 20 including a CPU, a RAM, a ROM, and the like, and a recording medium 30, and the control unit 20 can execute a program stored in the recording medium 30 and the ROM. In the present embodiment, the driving support program 21 can be executed as this program. The driving support program 21 causes the control unit 20 to execute a function for guiding the driver to improve fuel efficiency based on the driving data stored in the recording medium 30.

  The map information 30a is information used for specifying the position of the vehicle and route guidance of the vehicle, and specifies node data indicating the nodes set on the road on which the vehicle travels and the shape of the road between the nodes. Shape interpolation point data, link data indicating connection between nodes, and the like. The node data and the shape interpolation point data include information indicating the altitude of the position on the road corresponding to the node or the shape interpolation point, and the link data indicates whether or not the gradient section has a gradient change. Contains information. The vehicle in this embodiment (the vehicle on which the navigation device 10 is mounted) includes a GPS receiver 41, a vehicle speed sensor 42, a gyro sensor 43, a camera 44, a vehicle situation sensor 45, a driver situation sensor 46, a fuel sensor 47, and a communication unit. 48, an ECU (Electronic Control Unit) 49, and a user I / F unit 50. The functions of the driving support program 21 and various programs are realized by the cooperation of these units and the control unit 20.

  The GPS receiver 41 receives radio waves from GPS satellites and outputs information for calculating the current position of the vehicle via an interface (not shown). The control unit 20 acquires this signal and acquires the current position of the vehicle. The vehicle speed sensor 42 outputs a signal corresponding to the rotational speed of the wheels provided in the vehicle. The control unit 20 acquires this signal via an interface (not shown), and acquires a status value that specifies [speed]. In the following, the name of each status item will be indicated in brackets []. The control unit 20 acquires a status value that identifies [the number of stops] based on the number of times the vehicle speed becomes zero. The control unit 20 acquires a situation value that identifies [acceleration] and [deceleration] of the vehicle based on the differential value of the vehicle speed. [Acceleration] means acceleration in the same direction as the traveling direction acting on the vehicle when the vehicle is accelerating, and [Deceleration] is opposite to the traveling direction acting on the vehicle when the vehicle is decelerating. It means the acceleration of the direction. The gyro sensor 43 outputs a signal corresponding to the angular velocity acting on the vehicle. The control unit 20 acquires this signal via an interface (not shown) and acquires the traveling direction of the vehicle. The vehicle speed sensor 42 and the gyro sensor 43 are used for correcting the current position of the vehicle specified from the output signal of the GPS receiver 41. Further, the current position of the vehicle is appropriately corrected based on the travel locus of the vehicle. The control unit 20 acquires a status value that specifies [gradient], [road type], and [number of traffic lights] for the travel route based on the current position of the vehicle and the map information 30a.

  The camera 44 is attached to the vehicle so that the road ahead of the vehicle is included in the field of view, and outputs image data indicating the captured image. The control unit 20 obtains this image data via an interface (not shown) and performs image processing on the image data, whereby [number of interruptions of other vehicles], [road surface unevenness], and [road surface dryness]. ] Or [Status] that specifies [Vehicle distance]. The vehicle situation sensor 45 outputs signals corresponding to various situations of the vehicle. For convenience of illustration, the vehicle situation sensor 45 is shown by a single element, but the vehicle situation sensor 45 includes an oil sensor that generates a signal corresponding to a situation value that specifies [degradation level of engine oil], and [tires]. An air pressure sensor that generates a signal corresponding to a situation value that specifies [air pressure of the brake], a brake pad sensor that generates a signal corresponding to a situation value that specifies [the degree of wear of the brake pad], It includes a weight sensor that generates a signal corresponding to a situation value that specifies [carrying weight] such as an occupant, and a seating sensor that generates a signal that corresponds to a situation value that specifies [number of passengers]. The control unit 20 acquires each signal from the vehicle state sensor 45 via an interface (not shown).

  The driver situation sensor 46 outputs a signal corresponding to the situation of the driver. For convenience of illustration, the driver situation sensor 46 is shown as a single element. However, the driver situation sensor 46 includes a thermometer that generates a signal corresponding to a situation value that identifies the driver's [body temperature], and the driver. A pulse sensor that generates a signal corresponding to a situation value that specifies the [pulse rate] of the driver, and a sleepiness sensor that generates a signal corresponding to a situation value that specifies the driver's [sleepiness level]. A thermometer and a pulse sensor are, for example, contact sensors provided on a handle operated by a driver. The sleepiness sensor determines the sleepiness level based on, for example, the opening degree of the driver's eyes taken by the camera.

  The fuel sensor 47 detects the remaining amount of fuel in the fuel tank and generates a signal corresponding to the remaining amount. The travel distance can be obtained, for example, by integrating the speed of the vehicle. The communication unit 48 acquires a signal corresponding to a situation value that specifies [congestion distance], [traffic regulation], [weather], and [following wind amount] from the outside by wireless communication. An ECU (Electronic Control Unit) 49 executes control processing for various operations of the vehicle. The control unit 20 accesses the ECU 49 via an interface (not shown), and sets [electricity consumption], [accelerator opening], [brake operation], [handle operation], [shift operation], and [engine speed]. A signal corresponding to each specified situation value is acquired. For convenience of illustration, the ECU 49 is shown by a single element. However, a plurality of ECUs that share control processes for various operations may be provided, or a single ECU may perform control processes for various operations in an integrated manner. May be.

  The user I / F unit 50 is an interface unit for inputting a driver's instruction and providing the driver with various types of information including fuel efficiency guidance, and includes a touch panel display, a switch, a speaker, and the like (not shown). Yes. The control unit 20 outputs various guides by outputting a control signal to the user I / F unit 50.

  The control unit 20 provides guidance for improving fuel efficiency by executing the driving support program 21. For this purpose, the driving support program 21 includes a travel data creation unit 21a, a travel data acquisition unit 21b, a factor item specification unit 21c, and a guide unit 21d. Further, map information 30a and travel data 30b are recorded on the recording medium 30.

  The travel data creation unit 21a is a module that causes the control unit 20 to execute a process of creating travel data 30b in which the fuel economy and the situation value for each situation item are associated with each other. The control unit 20 uses the processing of the travel data creation unit 21a as a travel period from the time when the engine is ignited to the time when the engine is stopped, and acquires the status value for each status item in the travel period. And if an engine is stopped, the control part 20 will statistic each situation value of a situation item by the process of the driving | running | working data preparation part 21a. Here, a statistical method according to the nature of each status item is used.

For example, a value obtained by quantizing a travel distance ratio, which is a ratio of a distance between a general road and an expressway in a travel route traveled by the vehicle during the travel period, is set as a situation value for [road type]. In the present embodiment, the travel distance ratio between the general road and the highway is quantized into 10% intervals (100% / 0%, 90% / 10%, 80% / 20%...) Based on the map information 30a. . In addition, for vehicle [speed], [acceleration], etc., statistics of situation values specifying the vehicle speed and acceleration / deceleration at each moment are used, and the situation values are converted into average vehicle speed and acceleration / deceleration during the driving period. Convert to a status value indicating degrees. A value obtained by accumulating the number of traffic lights present on the travel route on which the vehicle has traveled during the travel period based on the map information 30a is converted into a status value for [number of traffic lights]. Further, a value obtained by accumulating the timing at which the vehicle speed has changed from a value other than 0 to 0 during the traveling period is set as a status value for [number of stops]. [Engine oil deterioration], [Tire air pressure], and [Brake pad wear] do not vary greatly during the running period. What is necessary is just to use the value as a status value as it is. The above statistics may be sequentially performed during the traveling period, or may be collectively performed when the engine is stopped.

  The control unit 20 acquires a signal corresponding to the remaining amount of fuel in the fuel tank from the fuel sensor 47 through an interface (not shown) by the processing of the traveling data creation unit 21a, and the traveling distance and the decrease amount of the remaining amount in the traveling period. The fuel consumption is calculated based on And the control part 20 matches driving | running | working data by associating the fuel consumption in a driving | running | working period, the status value of each situation item which performed the statistics about a driving | running | working period, and the identification value which identifies a driving | running | working period by the process of the driving | running | working data preparation part 21a. 30 b is created, and the travel data 30 b is recorded on the recording medium 30. In the present embodiment, the identification value specifies the time when the engine is ignited, that is, the start time of the travel period. The processing of the control unit 20 by the travel data creation unit 21a is executed every time the travel period ends, and travel data 30b having a different travel period is recorded on the recording medium 30.

  The travel data acquisition unit 21b controls the process of acquiring the current travel data 30b and the past travel data 30b having different fuel consumption from the current travel data 30b from among the plurality of travel data 30b recorded in the recording medium 30. This module is executed by the unit 20. The control unit 20 acquires, as the current travel data 30b, the travel data 30b with the newest start time of the travel period from the travel data 30b recorded on the recording medium 30 by the processing of the travel data acquisition unit 21b. The control unit 20 determines whether or not the fuel consumption corresponding to the current travel data 30b deviates from the fuel efficiency reference value by a threshold value or more by the processing of the travel data acquisition unit 21b. Unless the fuel efficiency corresponding to the current travel data 30b deviates from the fuel efficiency reference value by a threshold value or more, guidance regarding the fuel efficiency for the current travel data 30b is not performed. On the other hand, if the fuel consumption corresponding to the current travel data 30b deviates from the fuel efficiency reference value by a threshold value or more, guidance regarding the fuel efficiency for the current travel data 30b is performed.

  When it is assumed that guidance regarding fuel efficiency is performed for the current travel data 30b, the control unit 20 matches the current travel data 30b and the status value (travel distance ratio) of [road type] by the processing of the travel data acquisition unit 21b. And the driving | running | working data 30b with the most similar situation value about another situation item is acquired as past driving | running | working data 30b. The most similar traveling data 30b means the traveling data 30b having the smallest number of situation items having different situation values from the current traveling data 30b. The smaller the number of status items with different status values, the higher the similarity. Here, if the fuel consumption corresponding to the current travel data 30b is better than the threshold value from the fuel efficiency reference value, the travel data 30b having a fuel efficiency worse than that of the current travel data 30b is extracted from the travel data 30b, and the past travel is determined from that. Data 30b is acquired. On the other hand, if the fuel consumption corresponding to the current travel data 30b is worse than the threshold value from the fuel efficiency reference value, the travel data 30b having better fuel efficiency than the current travel data 30b is extracted from the travel data 30b, and the past travel is determined from that. Data 30b is acquired. Note that travel data 30b having the same fuel consumption as the current travel data 30b is not acquired as past travel data 30b.

  The factor item specifying unit 21c uses a plurality of situation items whose situation values fluctuate between the past travel data 30b and the current travel data 30b, and the fuel consumption corresponding to the current travel data 30b corresponds to the past travel data 30b. This is a module that causes the control unit 20 to execute processing that is specified as a factor item corresponding to a factor that fluctuates from the fuel consumption. The control unit 20 extracts a situation item whose situation value fluctuates between the past traveling data 30b and the current traveling data 30b by the process of the factor item specifying unit 21c. The control unit 20 subtracts the status value associated with the past travel data 30b from the status value associated with the current travel data 30b for each status item whose status value indicates the quantity by the processing of the factor item specifying unit 21c. Thus, the fluctuation amount of the situation value is calculated for each situation item whose situation value has fluctuated. For each status item whose status value indicates a concept rather than a quantity, the concept indicated by the status value associated with the current travel data 30b and the variation pattern of the concept indicated by the status value associated with the past travel data 30b are specified. . For example, for [weather], a fluctuation pattern such as “from sunny to rain” or “from sunny to cloudy” is specified.

  The control part 20 acquires the fuel consumption influence degree based on the fluctuation | variation of a situation value for every situation item whose situation value fluctuated by the process of the factor item specific | specification part 21c. The status value of each status item is different in the target and unit indicated by the value itself, but by converting the amount of fluctuation of the status value into a common fuel consumption impact level, the impact level of the situation value variation has on the fuel efficiency You can compare items. The control unit 20 specifies, as a factor item, a situation item that causes a change in a situation value at which the fuel efficiency influence level is equal to or greater than a predetermined threshold by the processing of the factor item identification unit 21c. In other words, a situation item that strongly influences the fuel consumption more than a certain amount due to the fluctuation of the situation value from the past travel data 30b is specified as a factor item. For the fluctuation amount of the situation value, the fuel consumption influence degree is calculated by multiplying the fluctuation amount by the weight. The situation value fluctuation pattern is converted into a fuel consumption influence degree corresponding to the fluctuation pattern by referring to the map.

  The guide unit 21d is a module that causes the control unit 20 to execute a process of causing the user I / F unit 50 to output a fuel efficiency guide corresponding to the current travel data 30b. First, the control unit 20 determines whether or not a causal relationship exists between a plurality of factor items by the process of the travel data acquisition unit 21b. That is, it is determined whether or not there is a causal relationship between a change in status value for a certain factor item and a change in status value for another factor item. The control unit 20 performs guidance that presents the causal relationship existing between the plurality of factor items by the processing of the travel data acquisition unit 21b. Here, a message is generated, and the user I / F unit 50 is instructed to display or output the message.

(1-2) Driving support processing:
Next, the driving support processing by the driving support program 21 will be described according to an embodiment. FIG. 2 is a flowchart showing a driving support process executed by the driving support program 21. The driving support process by the driving support program 21 is executed when new driving data 30b is recorded on the recording medium 30, that is, when the driving period is ended by stopping the engine. The control unit 20 acquires the newly recorded travel data 30b as the current travel data 30b from the travel data 30b recorded on the recording medium 30 by the processing of the travel data acquisition unit 21b (step S105).

Table 1 shows travel data 30b recorded on the recording medium 30 in the present embodiment.

  Table 1 shows some status items and their status values. In the traveling data 30b, the situation value means a unit quantity or concept according to the property of each situation item. Also, when the situation value indicates a concept such as “normal” or “low” instead of the quantity, a numerical value associated with these concepts is stored in the travel data 30b as the situation value. As shown in Table 1, a plurality of travel data 30b having different travel periods are recorded on the recording medium 30. In the present embodiment, the travel data 30b in the rightmost column in Table 1 is acquired as the current travel data 30b. For simplification of the table, only the month and day of the start time of the travel period are shown. In addition, each status item includes a driving operation status item whose status value depends on the driving operation while driving, a vehicle status item whose status value depends on the state of the vehicle other than the driving operation, and a status value which is the driver's status. It is classified into a dependent driver situation item and an ambient environment situation item whose situation value depends on the surrounding environment. In general, driving operation status items, vehicle status items, and driver status items are status items whose status values vary depending on the driver, and surrounding environment status items are status items whose status values do not depend on the driver. It can be said.

  When the current travel data 30b can be acquired, the control unit 20 determines whether or not the fuel consumption corresponding to the current travel data 30b is more than the threshold value by the processing of the travel data acquisition unit 21b (S110). . That is, it is determined whether or not the fuel consumption corresponding to the current travel data 30b is standard. If the fuel consumption corresponding to the current travel data 30b deviates from the predetermined fuel efficiency reference value by a threshold or more, the fuel consumption corresponding to the current travel data 30b is not within the standard range and corresponds to the current travel data 30b. When the fuel consumption does not deviate from the predetermined fuel consumption reference value by a threshold value or more, the fuel consumption corresponding to the current travel data 30b is standard. The fuel efficiency reference value may be a value indicating a standard fuel efficiency. For example, the fuel efficiency reference value may be an ideal fuel efficiency, may be a fuel efficiency specified by a vehicle manufacturer or the like, or may be an average fuel efficiency. May be. In the present embodiment, the average value of the fuel consumption in which the current travel data 30b and the current road data 30b in the travel data 30b recorded in the recording medium 30 are associated with the travel data 30b having the same status value (travel distance ratio). Is the fuel efficiency standard value. By determining the fuel efficiency reference value based on the travel data 30b recorded on the recording medium 30, it is determined whether or not the fuel efficiency corresponding to the current travel data 30b has changed significantly compared to the driver's own past driving history. can do.

If it is determined in step S110 that the status value corresponding to the current travel data 30b has not deviated from the fuel efficiency reference value by a threshold value or more, the control unit 20 ends the driving support process. That is, when the fuel consumption corresponding to the current travel data 30b is standard, the driving support process is terminated because it is not necessary to perform guidance described later. This is because when the fuel efficiency corresponding to the current travel data 30b is not significantly improved or deteriorated relative to the fuel efficiency reference value, there is no need to provide guidance on the fuel efficiency corresponding to the current travel data 30b. In addition, if the difference between the fuel efficiency corresponding to the current travel data 30b with respect to the fuel efficiency standard value is small, it is difficult to specify the factor item with high accuracy and appropriate guidance may not be performed. Because there is.

  When it is determined in step S110 that the situation value corresponding to the current travel data 30b is more than the threshold value from the fuel efficiency reference value, the control unit 20 is recorded on the recording medium 30 by the process of the travel data acquisition unit 21b. From the travel data 30b, the situation value of [road type] is the same as the situation value corresponding to the current travel data 30b (S115). In the example of Table 1, traveling data 30b for traveling on November 2, November 6, and November 8 is not extracted. When the status value (travel distance ratio) of [road type] is different, the fuel consumption characteristics are clearly different. Therefore, by performing extraction based on the coincidence of the situation values of [road type], it is possible to prevent the current driving data 30b from changing the fuel efficiency based on the driving data 30b having clearly different fuel efficiency characteristics. it can.

  Next, the control unit 20 determines whether or not the fuel efficiency corresponding to the current travel data 30b has improved from the fuel efficiency indicated by the fuel efficiency reference value by the processing of the travel data acquisition unit 21b (S120). When the fuel efficiency corresponding to the current travel data 30b is improved from the fuel efficiency indicated by the fuel efficiency reference value, the control unit 20 performs the current process from the travel data 30b extracted in step S115 by the process of the travel data acquisition unit 21b. The travel data 30b associated with the fuel efficiency worse than that corresponding to the travel data 30b is extracted (S125). By doing in this way, it is possible to identify a factor that improves the fuel efficiency of the current travel data 30b with reference to the travel data 30b associated with a fuel efficiency worse than that of the current travel data 30b.

  When the fuel consumption corresponding to the current travel data 30b is worse than the fuel efficiency reference value, the control unit 20 performs the current travel data from the travel data 30b extracted in step S115 by the processing of the travel data acquisition unit 21b. The travel data 30b associated with a fuel efficiency better than that corresponding to 30b is extracted (S130). In the example of Table 1, when it is assumed that the fuel consumption corresponding to the current travel data 30b is worse than the fuel efficiency reference value, the travel for travel on November 3, November 5, November 7, and November 12 Data 30b is extracted. By doing in this way, it is possible to specify a factor that the fuel efficiency of the current travel data 30b is deteriorated with reference to the travel data 30b associated with better fuel efficiency than the current travel data 30b.

  Next, the control unit 20 performs the processing of the travel data acquisition unit 21b, and from the travel data 30b extracted in steps S115 to S130, the travel data 30b has the least number of situation items different from the current travel data 30b. The travel data 30b having the largest number of status items with the same status value is acquired as past travel data 30b (S135). In other words, the travel data 30b that is most similar to the current travel data 30b and the situation values of the respective situation items is acquired as past travel data 30b. In the example of Table 1, travel data 30b for the travel on November 3 is extracted.

  When the current travel data 30b and the past travel data 30b can be acquired by the above processing, the control unit 20 performs processing between the current travel data 30b and the past travel data 30b by the processing of the factor item specifying unit 21c. The status item whose value has fluctuated is extracted (S140). In the example of Table 1, the situation items having different situation values between the past travel data 30b and the current travel data 30b relating to the travel on November 3 are [accelerator opening], [engine speed], [acceleration ], [Number of stops], and [Congestion distance] are extracted. In step S135, the current travel data 30b and the current travel data 30b whose situation values are most similar overall are acquired as past travel data 30b, so that the current travel data 30b is obtained from the past travel data 30b. It is possible to narrow down the number of situation items that cause the fuel consumption to fluctuate between 30b. In addition, since the current travel data 30b and the past travel data 30b relate to similar travel, the factor items can be identified with high accuracy by comparing the two.

  Next, the control unit 20 performs the processing of the factor item specifying unit 21c, and the situation item extracted in step S140 is associated with the current running data 30b from the situation value associated with the past running data 30b. By subtracting the value, the fluctuation amount of the situation value is calculated. Here, the fluctuation amount can be calculated by simply subtracting a status value indicating a specific quantity such as [engine speed]. On the other hand, a fluctuation pattern is specified for a situation item indicating a concept such as “normal”, “low”, and “high” instead of a specific quantity, such as [tire pressure]. For example, the variation pattern for [tire pressure] is specified as “from normal to low”.

  As described above, when the fluctuation amount and the fluctuation pattern are obtained for each situation item whose situation value has fluctuated, the control unit 20 performs processing of the factor item specifying unit 21c based on the fuel consumption influence degree due to the fluctuation of the situation value. A factor item is specified (S145). First, the control unit 20 converts the fluctuation amount or fluctuation pattern of the situation value into the fuel consumption influence degree. In the present embodiment, the fluctuation amount of the situation value is converted into the fuel consumption influence degree by multiplying the weight set for each situation item by the fluctuation amount. The weight is a value corresponding to the fluctuation amount of the fuel consumption that fluctuates when the situation value of each situation item changes by a unit amount. For example, since the acceleration fluctuation has a greater influence on the fuel consumption than the deceleration fluctuation, the acceleration weight is set larger than the deceleration weight. By multiplying the fluctuation amount by the weight, the fuel consumption influence degree corresponding to the fluctuation amount can be obtained. On the other hand, with respect to the fluctuation pattern, the fluctuation pattern is converted into the fuel consumption influence degree by referring to a map that defines the fuel consumption influence degree for each fluctuation pattern. The weight and the map may be prepared in advance based on the result of a fuel consumption test in which the vehicle is driven by changing the situation value of each situation item, and may be incorporated in the factor item specifying unit 21c.

  When the fuel consumption influence degree can be acquired for each of the situation items whose situation values fluctuate, the control unit 20 specifies, as a factor item, a situation item whose fuel consumption influence degree is greater than a predetermined threshold by the process of the factor item specifying unit 21c. As a result, only the situation items that have a large influence on the fuel efficiency due to the fluctuation of the situation value can be used as the factor items. In the example of Table 1, it is assumed that [accelerator opening], [number of stops], [congestion distance], and [acceleration] are specified as factor items.

As described above, when the factor item can be specified, the control unit 20 instructs the user I / F unit 50 to output the guidance on the fuel consumption corresponding to the current travel data 30b by the processing of the guide unit 21d ( S150). First, when a plurality of factor items are specified, the control unit 20 determines whether or not a causal relationship exists between the plurality of factor items by the processing of the guide unit 21d. Here, the map which prescribes | regulates the strength of the causal relationship between each status item is referred. This map is prepared in advance based on experience and experiment, and is incorporated in the factor item specifying unit 21c.

In the map of Table 2, the fluctuations in the situation values of the driving operation items arranged in the vertical direction, the vehicle situation items, and the driver situation items depend on the fluctuations in the situation values of the surrounding environmental situation items arranged in the horizontal direction. Is defined for each situation value. That is, a causal relationship is defined between the fluctuation of the situation value that varies depending on the driver and the fluctuation of the situation value that does not depend on the driver. The causal relationship of the fluctuation of the situation value of each situation item may differ depending on the specific fluctuation pattern of the situation value. For example, when the situation value indicates a concept such as [weather], the influence on the vehicle greatly varies depending on the fluctuation pattern of the situation value. Therefore, in the present embodiment, the current travel data 30b defines different causal relationships for [weather] depending on the variation pattern of the situation value. The fluctuation pattern means a combination (for example, “from sunny to rain”) of the situation value for the past travel data 30b and the situation value for the current travel data 30b. In the present embodiment, the status value variation pattern is unquestioned for status items whose status values indicate quantities. That is, for factor items that have fluctuations in status values that indicate quantities, whether or not the factor items themselves have a causal relationship with other factor items, regardless of the specific status value or the fluctuation pattern of the status values. Judgment. Of course, for status items whose status values indicate quantities, a causal relationship may be defined for each status value variation pattern (such as the range of status value values before and after the variation).

  In the example of Table 1, the factor item corresponding to the surrounding environment status items arranged in the horizontal direction is [congested distance]. Therefore, referring to Table 2, the situation values for [Congestion distance] fluctuate, and the situation values of [Accelerator opening], [Number of stops], and [Acceleration], which are other factor items, fluctuate. It is determined how strongly the is dependent. In this example, the situation value of the [accelerator opening] of the factor item fluctuates depending on the fact that the situation value of the [congestion distance] as the factor item fluctuates, and the situation of the [congestion distance] of the factor item It is determined that the “number of times to stop” of the factor item has changed strongly depending on the change of the value. On the other hand, it is determined that the situation value of the acceleration item “acceleration” has independently changed without depending on the situation value of the “congestion distance” of the factor item having changed.

As described above, when the causal relationship between the fluctuations in the situation value for the factor item can be determined, the control unit 20 performs guidance of the fuel consumption corresponding to the current travel data 30b by the processing of the factor item specifying unit 21c. Generate a message. The following is an example of a factor item for which it is determined that the change in the situation value has no causal relationship with the change in the situation value of the other factor items. That is, when the fuel efficiency corresponding to the current travel data 30b is improved from the fuel efficiency (fuel efficiency reference value) of the past travel data 30b, and the status value for a certain factor item [A] becomes the value (a),
"[A] became (a), so fuel efficiency improved."
Message is generated. In addition, when the factor items determined to have no causal relationship of fluctuation of the situation value are the driving operation situation item, the vehicle situation item, and the driver situation item whose situation values depend on the driver, the factor item Add a message to the effect that the status value should be improved. Conversely, when the fuel consumption corresponding to the current travel data 30b is improved from the fuel consumption of the past travel data 30b, a message indicating that the status value of the factor item should be maintained may be added.

On the other hand, a factor item that is determined to have a causal relationship in the fluctuation of the situation value is as in the following example. That is, for example, the fuel efficiency corresponding to the current travel data 30b has improved from the fuel efficiency (fuel efficiency reference value) of the past travel data 30b, and the situation value for a certain factor item [A] has changed to the value (a). Depending on the cause-and-effect relationship that the status value for the other factor item [B] has changed to the value (b),
"[A] became (a), and [B] became (b), which improved fuel efficiency."
Message is generated. Furthermore, if it is determined that the causal relationship is weak,
"[A] becomes (a), and [B] becomes (b), which is considered to have improved fuel efficiency."
In this way, a message is generated in which the predicate indicating the conclusion is changed to a weaker one. Thereby, the assertion degree of the causal relationship indicated by “by” in the message can be weakened. By weakening the causal relationship determination level, the driver can recognize that the factor item [B] may also correspond to a factor of improved fuel consumption.

In the example of Table 1, it is determined that there is no causal relationship in the fluctuation of the situation value (factor item) [acceleration]
"The fuel consumption has deteriorated due to the acceleration becoming 0.3G."
Is generated. In addition, regarding the [accelerator opening], [number of stops], and [congestion distance] that are determined to have a causal relationship to the fluctuation of the situation value,
"Since the jam distance was 2km, the number of stops was 8 and the fuel consumption deteriorated."
"It is thought that the fuel consumption deteriorated because the accelerator opening was 30% due to the congestion distance of 2 km."
When the message can be generated as described above, the control unit 20 causes the user I / F unit 50 to output the message as a fuel consumption guide corresponding to the current travel data 30b by the processing of the factor item specifying unit 21c. Instruct. Thereby, a message is output from the touch panel display or the speaker. By the way, when only one factor item is specified, a message indicating that the fuel consumption has fluctuated due to the status value of the factor item may be generated without performing the above-described causal relationship determination.

  As described above, in the present embodiment, when there is a causal relationship between the factors in which the fuel consumption varies between the current travel data 30b and the past travel data 30b, the causal relationship is presented to the driver. Therefore, appropriate guidance can be performed. In other words, if a factor that inevitably deteriorates fuel efficiency due to surrounding environmental factors that do not depend on the driver is inevitable, only the factor that directly deteriorated fuel efficiency is not presented. It can prevent making it uncomfortable. In addition, although the factor is generated depending on the surrounding environment factors that do not depend on the driver, it is possible to prevent the driver from deteriorating fuel consumption by trying to eliminate the factor. By accumulating a large number of travel data 30b in the recording medium 30, the similarity between the current travel data 30b and the past travel data 30b increases, and the identification accuracy of the factor items can be improved.

(3) Other embodiments:
In the first embodiment, the assertion level of the predicate indicating the conclusion of the message is changed according to the strength of the causal relationship. However, the higher the similarity between the current travel data 30b and the past travel data 30b, the more the message. You may make it strengthen the definite degree of the last word of.
In the first embodiment, both the factor item and its status value are presented in the presentation of the causal relationship. However, only the factor item may be presented in the presentation of the causal relationship, or only the status value in the presentation of the causal relationship. May be presented. As an example of the former, "Fuel efficiency has improved due to a decrease in the accelerator opening due to the gradient". "Fuel consumption has deteriorated due to an increase in electricity usage due to the" gradient "and" weather " “For the weather”. Examples of the latter include “for rain” because “fuel consumption has deteriorated due to increased electricity usage due to rain”. The mode of presenting the situation value is not limited to presenting the situation value itself, and the situation value is presented by the general tendency of the situation value “increased”, “decreased”, etc. as in the above example. May be. For example, “because the weather has deteriorated, the fuel consumption has deteriorated due to an increase in the amount of electricity used,” and “because the weather has deteriorated”.

  In the first embodiment, the time from the time when the engine is ignited to the time when the engine is stopped is defined as the travel period corresponding to the travel data 30b, but the travel period may be from the start to the end of travel. The travel period may be from the start to the end of travel in a certain travel section. By setting the traveling period to a short period, it is possible to provide guidance on short-term fuel consumption. For example, the travel data 30b having the travel period only during acceleration may be used to guide only the fuel consumption during acceleration. In this case, since the current travel data 30b can be acquired at the stage where the acceleration is finished, guidance can be provided every time the acceleration is finished.

  If the travel data 30b is created for each short travel period, the travel data 30b for a long travel period can be obtained by averaging the plurality of travel data 30b in the step S105. Furthermore, if the travel data 30b is created for each short travel period, the time at which the status value of each status item has changed can be specified, and therefore the simultaneity should be taken into account when determining the causal relationship of the status value variation. Can do. In addition, the traveling data 30b may be acquired from the outside of the vehicle (another vehicle of the same vehicle type or a similar vehicle type) via a communication unit such as the communication unit 48 or a portable storage medium such as a flash memory. In this case, traveling data 30b relating to traveling of another exemplary driver may be acquired. Conversely, when a plurality of drivers drive the same vehicle, travel data 30b is created in association with the driver, and only the travel data 30b that matches the driver is acquired as past travel data 30b. It may be.

  In the first embodiment, in the step S115, the past travel data 30b is acquired from the travel data 30b having the same [road type] status value. However, the travel data having the same status value of other status items is obtained. You may make it acquire the past driving | running | working data 30b from 30b. For example, the travel data 30b may be created for each travel section, and the past travel data 30b may be acquired from the travel data 30b with the same travel section. Thereby, for example, it is possible to provide guidance with high accuracy for traveling on a commuting route or the like.

  In the first embodiment, the situation items specified as the factor items are narrowed down based on the magnitude of the fuel consumption influence degree, but this process (part of S145) is not essential. That is, all the situation items whose situation values have changed may be specified as factor items. For example, when there are only a few situation items specified as factor items from the beginning, narrowing down based on the fuel consumption influence degree may be omitted. Thereby, processing can be made efficient. Further, in step S145, the fuel consumption influence degree corresponding to the fluctuation pattern of the situation value and the fluctuation amount of the situation value between the past running data 30b and the current running data 30b is relatively larger than the other situation items. A situation item may be specified as a factor item. For example, you may specify only the situation item in which a fuel consumption influence degree is less than the highest rank as a factor item.

DESCRIPTION OF SYMBOLS 10 ... Navigation apparatus, 20 ... Control part, 21 ... Driving support program, 21a ... Travel data creation part, 21b ... Travel data acquisition part, 21c ... Factor item specific | specification part, 21d ... Guide part, 30 ... Recording medium, 30a ... Map Information, 30b ... Travel data, 41 ... GPS receiver, 42 ... Vehicle speed sensor, 43 ... Gyro sensor, 44 ... Camera, 45 ... Vehicle status sensor, 46 ... Driver status sensor, 47 ... Fuel sensor, 48 ... Communication unit, 49 ... ECU, 50 ... User I / F part.

Claims (6)

Travel data in which the fuel consumption of the vehicle and the situation values for each of the plurality of situation items relating to the travel are associated with each other is acquired, and the current travel data, the current travel data, and the fuel consumption are obtained from the plurality of travel data. Traveling data acquisition means for acquiring past traveling data with different
Factor item specifying means for specifying, as factor items, a plurality of the situation items in which the situation value corresponding to the current driving data fluctuates from the situation value corresponding to the past driving data;
A driving means comprising a guide means for presenting a causal relationship between a plurality of the factor items when the fuel efficiency corresponding to the current travel data is guided from the fuel efficiency corresponding to the past travel data. Support device. The situation item includes an ambient environment situation item in which the situation value depends on the surrounding environment of the vehicle, and a driving operation situation item in which the situation value depends on a driving operation of the driver,
The guide means presents the causal relationship in which a change in the situation value for the factor item belonging to the driving operation situation item depends on a change in the situation value for the factor item belonging to the ambient environment situation item. The driving support device according to claim 1.   The travel data acquisition means acquires, as the past travel data, the travel data having the largest number of the situation items whose situation values match the current travel data among the travel data. The driving assistance device according to claim 1.   The driving support device according to any one of claims 1 to 3, wherein the guidance means increases the degree of presenting the causal relationship decisively as the causal relationship is stronger. Travel data in which a situation value and fuel consumption for each of a plurality of situation items related to vehicle travel are associated with each other is acquired, and the current travel data, the current travel data, and the fuel efficiency are obtained from the plurality of travel data. A driving data acquisition step of acquiring past driving data with different
The situation value corresponding to the current travel data is changed from the situation value corresponding to the past travel data, and the fuel efficiency of the current travel data is the fuel efficiency of the past travel data. A factor item identification process that identifies the factor item corresponding to the factor that fluctuated from
A guidance step of presenting a causal relationship between a plurality of the factor items when the fuel efficiency corresponding to the current travel data is guided from the fuel efficiency corresponding to the past travel data. Support method. Travel data in which a situation value and fuel consumption for each of a plurality of situation items related to vehicle travel are associated with each other is acquired, and the current travel data, the current travel data, and the fuel efficiency are obtained from the plurality of travel data. A travel data acquisition function for acquiring past travel data with different
The situation value corresponding to the current travel data is changed from the situation value corresponding to the past travel data, and the fuel efficiency of the current travel data is the fuel efficiency of the past travel data. A factor item identification function that identifies a factor item corresponding to a factor that has fluctuated since
A guidance function for presenting a causal relationship between a plurality of the factor items when the fuel efficiency corresponding to the current travel data is guided from the fuel efficiency corresponding to the past travel data. Driving assistance program to be realized.

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