Travelable distance calculation system and travelable distance calculation method for vehicle

A travelable distance calculation system for a vehicle includes a travel history database that stores first data, which includes an electricity consumption history of a target vehicle, and second data, which includes an electricity consumption history of a plurality of vehicles other than the target vehicle; and an arithmetic unit configured to calculates the travelable distance of the target vehicle using at least one of the first data and the second data. The arithmetic unit is configured to set a usage ratio between the first data and the second data according to an operation of a user of the target vehicle when calculating the travelable distance of the target vehicle.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2016-146656 filed on Jul. 26, 2016 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a system and a method for calculating the travelable distance of a vehicle.

2. Description of Related Art

In the present disclosure, the term “travelable distance” means the distance that a vehicle can travel while the electric power, stored in the electric storage device, or the fuel stored in the fuel tank (liquid fuel such as gasoline, light oil, and bioethanol, or gaseous fuel such as hydrogen) is consumed up to a predetermined amount. The travelable distance includes the maximum distance that a vehicle can travel when the electric power or the fuel is the maximum amount, but is not limited thereto. The travelable distance includes a distance that a vehicle can travel while the electric power or the fuel at an arbitrary point in time is consumed up to the predetermined amount.

When calculating the travelable distance of a certain vehicle, it is conceivable to use the travel history data actually traveled by other vehicles in the past. For example, the charge control system for an electric vehicle disclosed in Japanese Patent Application Publication No. 2013-070515 (JP 2013-070515 A) includes a travel history database. In this travel history database, travel history data including information on the vehicle type for a plurality of electric vehicles, travel routes, and the electric power consumption amounts on the travel routes is accumulated. When the electric vehicle of the user is charged, the travel history database is searched for the scheduled travel route, and the electric power consumption amount consumed when other electric vehicles traveled on the same travel route in the past is acquired. Then, based on the acquired electric power consumption amount, the amount of electric power necessary for traveling on the travel route is charged.

SUMMARY

The importance of accurately calculating the travelable distance of a vehicle is increasing. For a vehicle that does not have a motor and consumes fuel such as gasoline, there is always a demand for accurately knowing the distance travelable without refueling. This demand may be further increased when the technology of autonomous driving, developed in recent years, has become widespread. In addition, when traveling by an electric vehicle, a situation may occur more frequently in which the user must be conscious of whether the travelable distance (so-called EV travel distance) is sufficient for the distance from the present position to a charging facility such as a charging station.

The inventor of the present disclosure has found that, in the method of using the travel history data on a plurality of other vehicles (other vehicles) when calculating the travelable distance of a certain vehicle (target vehicle), there is room for improvement in the calculation accuracy of the travelable distance of the target vehicle from the viewpoint described below. For example, there are users who have different driving tendencies (habits of driving) different from general users. In addition, the driving skills to drive at low fuel consumption cost or low electric power cost vary from user to user. Therefore, if the travel history data of other vehicles is used uniformly, there is a case where the travelable distance of the target vehicle cannot be accurately calculated.

On the other hand, from the viewpoint of reflecting the driving tendency of the user of the target vehicle in the travelable distance of the target vehicle, it is conceivable to use the past travel history data on the target vehicle. However, for a route where the target vehicle has not traveled much in the past, the travel history data on the target vehicle is not sufficiently accumulated, sometimes with a possibility that there is a large variation in the travel history data. Therefore, even if the travel history data on the target vehicle is used, the travelable distance of the target vehicle may not be accurately calculated in some cases.

The present disclosure is a technique capable of improving calculation accuracy of a travelable distance in a travelable distance calculation system for a vehicle.

A travelable distance calculation system for a vehicle according to one aspect of the present disclosure includes a first storage device that stores an energy consumption history that includes one of a fuel consumption history and an electricity consumption history of a target vehicle as first data; a second storage device that stores the energy consumption history of a plurality of vehicles other than the target vehicle as second data; and an arithmetic unit that calculates a travelable distance of the target vehicle by using at least one of the first and second data. The arithmetic unit is configured to set a usage ratio between the first data and the second data according to an operation of a user of the target vehicle when calculating the travelable distance of the target vehicle.

A travelable distance calculation method for a vehicle, the vehicle including an arithmetic unit, according to another aspect of the present disclosure includes calculating, by the arithmetic unit, a travelable distance of a target vehicle using at least one of first data and second data, the first data including an energy consumption history of a target vehicle, the energy consumption history including one of a fuel consumption history and an electricity consumption history, the second data including the energy consumption history of a plurality of vehicles other than the target vehicle. The calculation described above includes setting, by the arithmetic unit, a usage ratio between the first data and the second data according to an operation of a user of the target vehicle when calculating the travelable distance of the target vehicle.

According to the above configuration or method, the usage ratio between the first data and the second data can be set according to the operation of the user of the target vehicle when calculating the travelable distance of the target vehicle. That is, the user himself/herself can determine the weighting of the first and second data that will be reflected on the travelable distance of the target vehicle. For example, when traveling on a route with a large number of past travels, the usage ratio of the first data may be set relatively high to more appropriately reflect the driving tendency of the user. Conversely, when traveling on a route with a small number of past travels, the usage ratio of the first data may be set relatively low and the second data may be mainly used in order to reduce the influence of the variation in the first data.

The user memorizes the past travel history of the routes such as the route on which the user is going to travel from now. Therefore, the user himself/herself can determine the weighting of the first and second data as described above in consideration of the past experience to reflect more appropriate data on the travelable distance of the target vehicle. As a result, the calculation accuracy of the travelable distance of the target vehicle can be improved.

Preferably, the plurality of vehicles may include vehicles of the same type as that of the target vehicle. The arithmetic unit may be configured to set the usage ratio using data on the vehicles of the same type, the date on the vehicle of the same type may be included in the second data.

According to the above configuration, since the energy consumption (travel distance per unit energy amount) history of the plurality of vehicles becomes almost the same as the energy consumption history of the target vehicle and the similarity becomes high, the calculation accuracy of the travelable distance of the target vehicle can be improved.

Preferably, the second storage device may store the second data for each traveling condition of the plurality of vehicles. The travelable distance calculation system may further include a display device configured to display an image that allows the user to select a traveling condition. When the second data is used, the arithmetic unit may be configured to calculate the travelable distance of the target vehicle using second data corresponding to a traveling condition selected by the user.

The traveling condition is, for example, a condition for a traveling period, traveling area, and outside air temperature. According to the above configuration, since the second data corresponding to a traveling condition selected by the user is used, that is, the user can narrow down the second data in consideration of a traveling condition, the calculation accuracy of the travelable distance of the target vehicle can be further improved.

Preferably, the display device may be configured to display at least one of a distribution of the second data corresponding to the traveling condition selected by the user and a distribution of travelable distances of the plurality of vehicles calculated using the second data corresponding to the traveling condition selected by the user.

When the user narrows down the second data in consideration of the traveling condition, the second data (or the travelable distance of a plurality of vehicles calculated using the second data) may simply be displayed. On the other hand, according to the above configuration, displaying the distribution of the second data allows the user to confirm the validity of the second data (the number of samples or the variation) and then narrow down the second data. Therefore, more appropriate second data can be reflected on the travelable distance of the target vehicle.

Preferably, when specific data is selected by the user from the at least one of distribution displayed on the display device, the display device may be configured to display a traveling condition of the vehicle corresponding to the specific data.

For example, it is possible that the user selects data with the longest travelable distance (that is, theoretically best data with the most efficient energy consumption) from the distribution displayed on the display device and, then, drives the vehicle so that the travelable distance becomes as close as possible to the travelable distance of the data. In such a case, according to the above configuration, the traveling condition (the accelerator work, the electric power consumption amount of the air conditioner, etc.) of the vehicle (vehicle that has achieved the theoretically best data) corresponding to the specific data is displayed on the display device to enable the user to know, under what traveling condition, the travelable distance was obtained. In addition, the user can know what kind of operation (accelerator work, setting of air conditioner, etc.) is to be performed to achieve the longest travelable distance.

Preferably, the display device may be configured to display the at least one of distributions such that the at least one of distributions when a deviation between an actual energy consumption history of the target vehicle and an energy consumption history calculated according to a setting by the user exceeds a predetermined level is larger than the at least one of distributions when the deviation between an actual energy consumption history of the target vehicle and an energy consumption history calculated according to a setting by the user is less than the predetermined level.

According to the above configuration, the selection range given to the user is expanded, for example, when the user selects an arbitrary portion of the distribution of the second data (or the distribution of the travelable distances) on the display screen and, therefore, the user can easily select the second data that matches user's driving tendency.

Preferably, the travelable distance calculation system for a vehicle further may include a display device configured to display a bar for allowing the user to adjust the usage ratio.

According to the above configuration, the bar is used as a user interface to allow the user to intuitively adjust the usage ratio. The usage ratio can be selected, for example, between the minimum value (for example 0%) and the maximum value (for example 100%).

Preferably, the second storage device may be provided in a data center that is outside the target vehicle and outside the plurality of vehicles. The target vehicle may include the first storage device and sends the first data to the data center. The data center may include a server that sets the usage ratio.

It is also possible to directly send the second data from the plurality of vehicles to the target vehicle not via the data center to allow the target vehicle to store (accumulate) the second data, to calculate the energy consumption, and to calculate the travelable distance. However, in practice, this configuration is not realistic because the amount of communication data in the entire system becomes too large. On the other hand, according to the configuration described above, the first and second data is collected in the data center, and the energy consumption is calculated in the data center. As a result, the amount of communication data in the entire system can be reduced.

Preferably, the target vehicle may be configured to send the first data to the data center periodically or when a predetermined condition is satisfied.

In some cases, because the vehicle travels in places where wireless communication is difficult (such as in a tunnel, etc.), the first data cannot always be sent from the vehicle. According to the above configuration, the first data is sent periodically or when a predetermined condition is satisfied (for example, when the vehicle is charged), meaning that data can be sent more reliably.

According to the present disclosure, the travelable distance calculation system for a vehicle can improve the calculation accuracy of the travelable distance.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will be described in detail below with reference to the drawings. In the drawings, the same reference numeral is attached to the same or corresponding part, and the description thereof will not be repeated.

In the following embodiments, a configuration for calculating the travelable distance of an electric vehicle (EV travel distance) will be described as an example. However, the “target vehicle” and the “plurality of vehicles” according to the present disclosure are not limited to an electric vehicle, but may be a vehicle not equipped with a motor for traveling and an electric storage device (such as a gasoline vehicle or a diesel vehicle), a hybrid vehicle, or a fuel cell vehicle. When the “target vehicle” and the “plurality of vehicles” are electric vehicles, the electricity consumption history is used as the “energy consumption history” according to the present disclosure. On the other hand, when the “target vehicle” and the “plurality of vehicles” are gasoline vehicles or hybrid vehicles, the fuel consumption history is used as the “energy consumption history”.

FIG. 1is a diagram generally showing the overall configuration of a travelable distance calculation system for a vehicle according to a first embodiment. A travelable distance calculation system9includes a vehicle1(target vehicle) of a user (not shown), a plurality of vehicles2(hereinafter also referred to as “other vehicles”) that are not the user's vehicle and are vehicles other than the vehicle1, and a data center3. The vehicle1and the data center3are configured to be able to communicate with each other. The plurality of vehicles2and the data center3are also configured to be able to communicate with each other. Although not shown, the vehicle1and the plurality of vehicles2may also be configured to be able to communicate with each other.

In this embodiment, the vehicle1and each of the plurality of vehicles2are an electric vehicle. Each of the plurality of vehicles2is preferably an electric vehicle having substantially the same electricity consumption (travel distance per unit electric power consumption amount) as the vehicle1, and more preferably, an electric vehicle of the same vehicle type as the vehicle1. An electric vehicle having substantially the same electricity consumption as the vehicle1may be an electric vehicle having the same vehicle weight classification, such as a small car, a middle-sized car, or a large car, or may be an electric vehicle having the same type of vehicle such as a sedan, a station wagon, or a van. Meanwhile, an electric vehicle of the same vehicle type as the vehicle1means an electric vehicle of the same model (vehicle name) in a narrower definition and, more preferably, an electric vehicle of the model and the same year. The data center3collects travel history data (first data) D1, which includes the electricity consumption history during the travel of the vehicle1, and travel history data (second data) D2which includes the electricity consumption history during the travel of the plurality of vehicles2. The data center3calculates the travelable distance of the vehicle1by using at least one of the data D1and D2. This calculation method will be described later in detail.

FIG. 2is a diagram showing the configuration of the vehicle1and the data center3, shown inFIG. 1, in more detail. Although not shown, each of the plurality of vehicles2has basically a configuration common to that of the vehicle1.

The vehicle1includes a navigation system10, an inlet210, a converter220, an electric storage device230, a battery Electronic Control Unit (ECU)240, an air conditioner250, a vehicle ECU260, and a communication module270. The navigation system10, the battery ECU240, the vehicle ECU260, and the communication module270are connected to each other by an in-vehicle Local Area Network (LAN)280.

The inlet210is configured in such a way that the plug (not shown) of the charging cable can be connected from the power supply external to the vehicle1(for example, the system power supply not shown) during the charging of the electric storage device230. The converter220converts the voltage of the electric power, supplied from the power source external to the vehicle1via the inlet210, into the voltage chargeable to the electric storage device230. The electric storage device230is a rechargeable DC power supply. The electric storage device230is configured to include a secondary battery such as a lithium ion battery or a nickel hydrogen battery, or a capacitor such as an electric double layer capacitor (none of which are shown).

The battery ECU240monitors the voltage, current, and temperature of the electric storage device230and, at the same time, controls charging and discharging of the electric storage device230. In addition, the battery ECU240calculates the charge state (SOC: State Of Charge) of the electric storage device230based on the monitoring result of the electric storage device230.

The air conditioner250performs air conditioning (heating or cooling) in the passenger compartment of the vehicle1using the electric power supplied from the electric storage device230. The electric power consumption of the air conditioner250is calculated by the vehicle ECU260by monitoring the current, supplied to the air conditioner250, using, a current sensor or the like not shown. The vehicle ECU260controls the air conditioner250and, at the same time, controls the devices (for example, the driving device of the motor not shown) so that the vehicle1is in the desired state.

The vehicle1is configured to be able to carry out data communication with the data center3via the communication module270. The vehicle1sends the identification information including the vehicle type of the vehicle1, travel history data on the vehicle1(data D1), and the SOC of the electric storage device230to the data center3and, at the same time, receives the travelable distance of the vehicle1(details will be described later) from the data center3. The vehicle1can also receive the road traffic information (traffic jam, accident, construction, lane restriction, traffic regulation and other information), as well as the weather information (weather information, temperature etc.), from the data center3via the communication module270.

The navigation system10includes an arithmetic unit100, a map data storage unit110, a Global Positioning System (GPS) receiver120, a traveling state detection unit130, a navigation screen140, a speaker150, and a storage device160.

The map data storage unit110stores, for example, road map data and facility data, such as various shops, associated with the road map data. The GPS receiver120identifies (locates) the current position of the vehicle1based on the radio waves from artificial satellites. The traveling state detection unit130, configured by a gyroscope, a geomagnetic sensor, and the like (none of which are shown), detects the traveling state of the vehicle1.

The navigation screen140, for example, a liquid crystal display with a touch panel, displays various kinds of information and accepts a user's operation. By operating the navigation screen140, the user can set the destination of the vehicle1and select a travel route. The speaker150outputs speech. The navigation screen140corresponds to the “display device” according to the present disclosure. However, the “display device” according to the present disclosure is not limited to the navigation screen140but may be, for example, a head-up display. In addition, a user operation may be accepted by the operation of a mechanical switch provided on a center console, a steering wheel, or the like or by a voice input from the microphone.

The storage device160, for example, a hard disk device, stores travel history data (data D1) actually traveled by the vehicle1in the past. The data D1includes, for example, the information on the travel route of the vehicle1(more specifically, data generated by dividing the travel route into a plurality of sections with intersections or the like as nodes and by defining each portion between each two nodes as a link) and the information on the amount of electric power supplied from the electric storage device230in each link (electricity consumption history). The data D1may include the information indicating the driving state (acceleration/deceleration, braking, etc.) of the vehicle1in each link and the information on the electric power consumption amount of the air conditioner250. The data D1stored in the storage device160is sent to the data center3via the communication module270either periodically or when a predetermined condition is satisfied. Because the vehicle1sometimes travels in places where wireless communication is difficult (for example, in a tunnel), the data D1cannot always be sent from the vehicle1. Sending the data D1either periodically or when predetermined conditions are satisfied (for example, when charging the vehicle1) allows for more reliable transmission.

The arithmetic unit100is configured to include a Central Processing Unit (CPU), a memory (Read Only Memory (ROM) and Random Access Memory (RAM)), and an input/output buffer, though none of which are shown. The arithmetic unit100calculates the current position, traveling direction, and speed of the vehicle1based on the signals from each sensor included in the GPS receiver120and the traveling state detection unit130.

In addition, the arithmetic unit100performs various types of navigation processing of the vehicle1. More specifically, based on the current position of the vehicle1and the road map data from the map data storage unit110, the arithmetic unit100displays the current position of the vehicle1on the navigation screen140with the current position overlaid on the road map around the vehicle1. Furthermore, the arithmetic unit100implements the route guidance function for guiding the vehicle1along the recommended route from the current position of the vehicle1to the destination. That is, the arithmetic unit100receives the recommended route, calculated by the route search processing by the server300(described later) of the data center3, via the communication module270. Then, the arithmetic unit100causes the navigation screen140to display the recommended route and, when the vehicle1reaches a predetermined point, causes the speaker150to output the guidance voice.

The data center3includes a server300, a map database310, a road traffic information acquisition unit320, a weather information acquisition unit330, a travel history database340, and a communication device350.

The map database310stores road map data for the route search processing. The road traffic information acquisition unit320acquires, for example, the latest road traffic information provided from the road traffic information center. The weather information acquisition unit330acquires the latest weather information provided, for example, by the weather bureau. The travel history database340, for example, a hard disk device, stores travel history data (data D1) sent from the vehicle1and travel history data (data D2) sent from the plurality of vehicles2. Since the data D2includes the same type of information as that of the data D1, the detailed description will not be repeated. The communication device350is configured to be able to carry out data communication with the communication module270mounted on the vehicle1. Note that the travel history database340corresponds to both the “first storage device” and the “second storage device” according to the present disclosure.

Like the arithmetic unit100, the server300is configured to include a CPU, a memory, and an input/output buffer (none of which are shown). The server300stores the data D1, received from the vehicle1, in the travel history database340by stratifying the data D1by vehicle type and by traveling condition (described later). Similarly, the server300stores the data D2, received from the plurality of vehicles2, in the travel history database340by stratifying the data D2by vehicle type and by traveling condition. In addition, the server300performs the route search processing based on the information on the current position and the destination of the vehicle1, and sends the obtained recommended route to the vehicle1via the communication device350. Furthermore, as described below, the server300calculates the travelable distance of the vehicle1using the electricity consumption history included in the data D1and D2.

When calculating the travelable distance of the vehicle1, the travel history data (data D2) actually traveled by the other vehicles in the past may be used as disclosed, for example, in Japanese Patent Application Publication No. 2013-070515 (JP 2013-070515 A). However, users have driving tendencies (driving habits) different for each user, and there are users who always try to keep a good electricity consumption while there are users who do not particularly care about the electricity consumption. In addition, the driving skills to drive at low electricity consumption also vary from user to user. For example, when the user of the vehicle1has a driving tendency or skill different from that of a general user (users of other vehicles), the travelable distance of the vehicle1cannot be accurately calculated in some cases if the data D2is uniformly used.

On the other hand, from the viewpoint of reflecting the driving tendency of the user of the vehicle1on the travelable distance of the vehicle1, it is conceivable to use only the data D1. However, for a route having a small number of past travels of the vehicle1, there is a possibility that the data D1is not sufficiently accumulated and the variation in the data D1is large. Therefore, even if the data D1is used, the travelable distance of the vehicle1cannot be accurately calculated in some cases.

Therefore, in this embodiment, a configuration is employed in which the “usage ratio” between the data D1and the data D2can be set (or changed) by a user operation when calculating the travelable distance of the vehicle1. The usage ratio is the ratio between the degree of reflecting the electricity consumption history of the vehicle1and the degree of reflecting the electricity consumption history of other vehicles, in the travelable distance of the vehicle1. Then, the electricity consumption is calculated using the data D1and D2according to the usage ratio that is set by the user and, based on the electricity consumption calculation result, the travelable distance of the vehicle1is calculated.

In other words, in this embodiment, the user of the vehicle1can determine himself/herself how much to reflect the past travel history of the vehicle1when calculating the travelable distance of the vehicle1. Since the user remembers how frequently and how the vehicle traveled in the route, on which the vehicle1is going to travel, in the past, it is possible to appropriately determine the degree to which the data D1should be reflected. For example, for a route with a large number of past travels, the usage ratio of the data D1can be set higher than the usage ratio of the data D2to appropriately reflect the driving tendency of the user. Alternatively, for a route with a small number of past travels, the usage ratio can be set so that the data D2is mainly used.

As described above, the user himself/herself can determine the weighting of the data D1and the data D2by considering past experiences, with the result that more appropriate data (electricity consumption history) is reflected in the travelable distance of the vehicle1. As a result, the calculation accuracy of the travelable distance of the vehicle1can be improved.

The processing for calculating the travelable distance of the vehicle1in the first embodiment (hereinafter also referred to as “travelable distance calculation processing”) will be described below in detail.

FIG. 3is a flowchart showing the travelable distance calculation processing according to the first embodiment. InFIG. 3, the case where the destination of the vehicle1is set by the user will be described.

The processing shown inFIG. 3andFIGS. 5 to 7is called from the main routine (not shown) and executed when predetermined conditions are met (for example, when the user operates the navigation screen140to set a destination). The left side of the figure shows a series of processing executed by the arithmetic unit100of the vehicle1, and the right side of the figure shows a series of processing executed by the server300of the data center3. Each step (hereinafter abbreviated as “S”) included in these flowcharts is basically implemented by the software processing by the arithmetic unit100or the server300, but some or all of the processing may be implemented by the hardware (electric circuit) included in the arithmetic unit100or the server300.

In S110, the arithmetic unit100sends the current position of the vehicle1and the information indicating the destination set by the user, as well as a request to calculate a recommended route of the vehicle1to the destination (recommended route request), to the server300. The server300executes the route search processing, based on the current position of the vehicle1, the destination, and the road traffic information, to calculate a recommended route of the vehicle1and sends the calculated recommended route to the arithmetic unit100(S210). As a result, the travel route of the vehicle1in the current travel (trip) is set. Although not shown, a plurality of recommended routes may be sent from the server300to the arithmetic unit100to allow the user to select one of them. In addition, instead of the server300executing the route searching processing, the arithmetic unit100executes the route searching processing and sends the calculated travel route from the arithmetic unit100to the server300.

In S120, the arithmetic unit100sends to the server300a request to calculate the travelable distance of the vehicle1(travelable distance request) in the travel route that was set in the processing in S110and S210. In S130, the arithmetic unit100acquires the SOC of the electric storage device230from the battery ECU240and sends it to the server300.

In S140, the arithmetic unit100controls the navigation screen140so that the setting operation of the usage ratio by the user is accepted. The usage ratio that is set by user operation is sent to the server300.

FIGS. 4A and 4Bare diagrams showing the setting operation of the usage ratio by the user.FIGS. 4A and 4Bshow an example of an image displayed on the navigation screen140(display with a touch panel). For example, when setting the usage ratio, the message “Please set usage ratio of electricity consumption data between your vehicle and other vehicles”, as well as the operation bar for setting the usage ratio of data D1and data D2, is displayed. By using the operation bar such as the one shown inFIG. 4AandFIG. 4Bas an user interface, the user can intuitively adjust the usage ratio. This usage ratio can be selected, for example, between the minimum value (0%) and the maximum value (100%).

For example, when the vehicle1travels on a route having a large number of travels by the vehicle1(the route with a large number of samples of the data D1) such as a user's commuting route, it is considered that the data D1should be given more importance than the data D2. Therefore, as shown inFIG. 4A, the user sets the usage ratio (R1:R2) between the data D1and the data D2, for example, to 100%:0% (R1:R2=100%:0%). This setting allows the travelable distance of the vehicle1to be calculated using only the data D1that reflects the driving tendency (driving habits) of the user.

On the other hand, when the vehicle1travels on a route having a relatively small number of travels by the vehicle1, the variations in the data D1may be relatively large since the number of samples of the data D1is small. Therefore, it is considered preferable to place importance on the data D2rather than the data D1. Therefore, as shown inFIG. 4B, the user sets the usage ratio to, for example, 10%:90% (R1:R2=10%:90%). This setting allows the travelable distance of the vehicle1to be calculated by mainly using the data D2(that is, using the electricity consumption data on average travel), which is based on the past travel history of many other users, while reducing the influence of the variation with respect to the data D1which is based on the user's own past travel history.

Note that the operation bars shown inFIGS. 4A and 4Bare merely examples of the image for the operation to set the usage ratio and that the operation method is not limited thereto. For example, a numeric value input screen may be displayed on the navigation screen140to allow the user to input a numerical value indicating the usage ratio. Alternatively, the usage ratio may be accepted by voice input.

Returning toFIG. 3, regarding the travel route of the vehicle1(the recommended route calculated in S210), the server300reads the past data D1and D2from the travel history database340in S220.

In S230, the server300calculates the electricity consumption required in traveling on the travel route of the vehicle1during the current run based on the usage ratio that was set in S140. More specifically, as shown in the following expression (1), the server300divides the travel route of the vehicle1into a plurality of links Li (i is a natural number). Then, for each link Li, the server300calculates the sum of the result, obtained by multiplying the electricity consumption E1of the vehicle1in the link Li by the usage ratio R1of the data D1, and the result, obtained by multiplying the electricity consumption E2of the other vehicles in the link Li by the usage ratio R2of the data D2, as the electricity consumption Qifor that link.
Qi=E1×R1+E2×R2  (1)

For example, when the usage ratio is set to R1:R2=10%:90% as shown inFIG. 4B, assume that the electricity consumption E1of the vehicle1and the electricity consumption E2of the other vehicles for the kth link Lk(k is a natural number) are 6.0 (km/kWh) and 8.0 (km/kWh) respectively. Then, the electricity consumption Qkfor that link Lkis calculated as Qk=6.0×0.10+8.0×0.90=7.8 (km/kWh). In this manner, the electricity consumption Qiof all the links Liincluded in the travel route of the vehicle1, is calculated.

As the electricity consumption E2of the other vehicles, the median value, the average value, or the mode of the data of the plurality of vehicles2, included in the data D2, may be used. The same is true for the electricity consumption E1of the vehicle1.

In S240, the server300calculates the travelable distance of the vehicle1using the SOC of the electric storage device230, acquired from the vehicle1in S130, and the electricity consumption calculation result calculated in S230. More specifically, for each link Liincluded in the travel route of the vehicle1, the arithmetic unit100calculates the electric power consumption amount [unit: kWh] in the link Libased on the length [unit: km] of the link Liand the electricity consumption Qi[unit: km/kWh] in the link Li. Then, the arithmetic unit100converts the SOC of the electric storage device230into the remaining electric power amount. After that, as the travelable distance of the vehicle1, the arithmetic unit100calculates the integrated value of the lengths of the link Lialong the travel route, from the current position of the vehicle1to the point where the remaining electric power amount of the electric storage device230reaches the predetermined value (lower limit value). The server300sends the calculated travelable distance to the arithmetic unit100.

In S150, the arithmetic unit100displays the travelable distance, received from the server300, on the navigation screen140. After that, the processing returns to the main routine. The travelable distance of the vehicle1can be serially updated to the latest value by repeatedly executing a series of processing by the steps inFIG. 3except S110, S210, and S140. This update processing is not explicitly shown in the figure.

The order in which the information and requests are sent from the arithmetic unit100to the server300in S110to S140is not fixed, but the order may be changed as necessary. Alternatively, these pieces of information and requests may be sent at a time.

In the first embodiment, when calculating the travelable distance of the vehicle1, the user can perform an operation on the navigation screen140, as described above, to set the weighting between the data D1, which includes the electricity consumption history of the vehicle1, and the data D2, which includes the electricity consumption history of the plurality of vehicles2(other vehicles).

The user memorizes the past travel history of the route on which to travel. For example, the user memorizes the past traveling frequency of the travel route. In addition, the user memorizes what were the conditions during past traveling, such as the occurrence of congestion due to an accident during the traveling of the vehicle1or an exceptional weather condition such as heavy rain or snow fall. In addition, the user also knows a plan (hope) as to what the user wants to do this time, for example, whether the user wants to travel with priority on the electricity consumption or whether the user wants to reach the destination in a short time without paying much attention to the electricity consumption. Therefore, based on the memory of the user himself/herself, the user can determine whether the past travel history of the user is similar to the present travel schedule and, according to the determination result, put a weight on the electricity consumption.

When the current travel schedule is similar to the travel history of the past, the user can set the usage ratio R1(in other words, the weight) of the data D1relatively higher; on the other hand, when the current travel schedule is not similar much to the past travel history, the user can set the usage ratio R1of the data D1relatively lower (that is, the usage ratio R2of the data D2relatively higher). In this way, the user can set the usage ratio between the data D1and D2by himself/herself to allow the weighting of the electricity consumption history, which is determined based on the user's past travel history and the current travel schedule, to be appropriately determined based on the user's experience. As a result, the calculation accuracy of the travelable distance of the vehicle1can be improved.

The processing method in which the data D2is sent from the plurality of vehicles2, not via the data center3, but directly to the vehicle1to allow the vehicle1to accumulate the data D2, to calculate the electricity consumption, and to calculate the travelable distance is not realistic, because the amount of communication data in the whole travelable distance calculation system9becomes too large. On the other hand, according to the first embodiment, the data D1and D2are collected and accumulated in the data center3, the electricity consumption and the travelable distance are calculated in the data center3, and the calculation result is sent from the data center3to the vehicle1. This processing method makes it possible to reduce the amount of communication data in the whole travelable distance calculation system9.

In the first embodiment, the configuration, in which the server300of the data center3calculates the travelable distance, has been described. However, the travelable distance may be calculated also by the arithmetic unit100of the vehicle1.

FIG. 5is a flowchart showing the travelable distance calculation processing according to a first modification of the first embodiment. The processing in S310and S410is equivalent to the processing in S110and S210(seeFIG. 3) in the first embodiment.

In S320, the arithmetic unit100sends to the server300a request to calculate the electricity consumption data (electricity consumption data request) in the travel route of the vehicle1. In S330, the arithmetic unit100controls the navigation screen140so that a user operation for setting the usage ratio may be accepted.

In S420, the server300reads the past data D1and D2for the travel route of the vehicle1from the travel history database340. In S430, the server300calculates the electricity consumption data on the travel route of the vehicle1based on the usage ratio that was set in S330. The processing described above is equivalent to the processing in S220and S230in the first embodiment. The server300sends the calculated electricity consumption data (electricity consumption calculation result) to the arithmetic unit100.

In S340, the arithmetic unit100acquires the SOC of the electric storage device230from the battery ECU240. In S350, the arithmetic unit100calculates the travelable distance of the vehicle1based on the SOC of the electric storage device230and the electricity consumption calculation result sent from the server300in S430. This process is equivalent to the process of S240in the first embodiment. In addition, the arithmetic unit100displays the calculated travelable distance on the navigation screen140(S360).

According to the first modification of the first embodiment, the user performs an operation on the navigation screen140as described above to set the usage ratio between the data D1and the data D2as in the first embodiment. This allows the calculation accuracy of the travelable distance of the vehicle1to be improved also in a configuration in which the travelable distance is calculated by the arithmetic unit100.

[Second modification of first embodiment] In the first embodiment (and first modification thereof), the processing has been described in which the travelable distance of the vehicle1is calculated after setting the travel route of the vehicle1. However, the setting of the travel route is not indispensable and, as described below, the calculation accuracy of the travelable distance can be improved even when the travel route is not set.

FIG. 6is a flowchart showing the travelable distance calculation processing according to a second modification of the first embodiment. This flowchart is different from the flowchart (seeFIG. 3) in the first embodiment in that the processing of S110and S210is not included and that the processing of S510is included instead of the processing of S120and S220.

In S510, the arithmetic unit100sends to the server300the information indicating the current position of the vehicle1, as well as a request to calculate the travelable distance that the vehicle1will be able to travel in the area near the current position of the vehicle1(more specifically, the area in a predetermined range (for example, 50 km range) centered on the current position of the vehicle1). This is because there are areas with many slopes or areas where traffic congestion tends to occur and therefore the data D2, which includes the electricity consumption history of other vehicles, can differ from area to area. The predetermined range described above may be a predetermined fixed value or a variable value that can be changed by a user's operation.

The subsequent processing of S520and S530is equivalent to the processing in S130and S140respectively in the first embodiment. That is, the arithmetic unit100sends the information, which indicates the SOC of the electric storage device230and the usage ratio of the travel history data, to the server300.

In S610, the server300reads data D1and D2about the area near the current position of the vehicle1from the travel history database340. The subsequent processing in S620, S630, and S540is equivalent to the processing in S230, S240, and S150in the first embodiment, respectively, and detailed description thereof will not be repeated.

According to the second modification of the first embodiment, even when the travel route of the vehicle1is not set, the calculation accuracy of the travelable distance of the vehicle1can be improved by extracting the data D2on the area, for example, within a predetermined range centered on the current position of the vehicle1as described above.

The data D2, read from the travel history database340when calculating the travelable distance of the vehicle1, includes data under various traveling conditions or traveling environments. Depending on what kind of data is to be extracted from such various types of data D2, the calculation result of the travelable distance of the vehicle1may be different. Therefore, in order to further improve the calculation accuracy of the travelable distance, it is considered preferable to narrow down the data D2and use more appropriate data for calculating the travelable distance. To meet such a need, a configuration will be described in the second embodiment that allows the user to perform an operation for narrowing down the data D2and, at the same time, gives the user a motivation to perform such a user operation.

FIG. 7is a flowchart showing the travelable distance calculation processing in the second embodiment. This flowchart is different from the flowchart in the first embodiment (seeFIG. 3) in that the processing in S740, S820, S830, S750, and S760(indicated by the broken line) is added for narrowing down the data D2according to the traveling conditions. The processing in S710, S810, S720, and S730is equivalent to the processing in S110, S210, S120, and S130in the first embodiment.

In S740, the arithmetic unit100accepts an operation performed by the user to set traveling conditions. This control is implemented by the arithmetic unit100that displays a predetermined setting screen, such as the one shown below, on the navigation screen140.

FIG. 8is a diagram showing an example of the traveling condition setting screen. For example, as the traveling conditions, the traveling period, the outside air temperature, the accelerator work, the usage amount of the air conditioner250, and the number of occupants of the vehicle1may be set. The traveling period and the outside air temperature of the vehicle1will be described later with reference toFIGS. 9 to 11.

The accelerator work is one indicator indicating the driving tendency of the user. For example, the user can set the indicator, which indicates the accelerator work, to one of the following two extraction modes: in one mode, the data D2on the other vehicles similar to the data D1of the vehicle1is selectively extracted and, in the other mode, the data D2is extracted irrespective of the similarity/dissimilarity between the data D2and the data D1. The similarity/dissimilarity of the accelerator work can be determined, for example, by the frequency (the number of times per unit time) at which a specific traveling pattern that the user's driving tendency is likely to occur appears. For example, the vehicle of a user who prefers to overtake other vehicles often shows a traveling pattern in which the vehicle once accelerates from approximately 40 km/h to approximately 60 km/h and, then, travels again at approximately 40 km/h. Therefore, by classifying the driving tendency of the users according to the frequency at which such a traveling pattern appears, the similarity/dissimilarity between the driving tendency of one user and the driving tendency of another user can be determined.

In addition, since the electric power consumption by the air conditioner250can have a large influence on the travelable distance of the vehicle1, it is desirable to take into consideration the degree of the use of the air conditioner250. Therefore, the user can select between cooling and heating and, at the same time, set the strength of the air volume, for example, in five stages.

Furthermore, the weight of the vehicle1can also have an influence on the travelable distance of the vehicle1. When the vehicle1and the vehicle2are the same type of vehicle, the user may select, for example, the number of occupants since the weights of the vehicles are considered to be about the same. The number of occupants may be detected by a load sensor provided on the seat, or may be detected by the tire air pressure sensor (none shown). It is also possible to estimate the number of occupants by the number of times the door (not shown) is opened and closed.

One or more of the traveling conditions described above are selected by a user operation and then sent to the server300. It is preferable that the initial values of the traveling conditions be displayed on the navigation screen140by the arithmetic unit100according to the detection results of the various sensors (that is, the recommended values are suggested from the arithmetic unit100to the user) and that those values be changeable by the user.

Returning toFIG. 7the server300reads the data D2from the travel history database340in S820. This data D2is related to the travel route, which was set in S710and S810, and that has been narrowed down according to the user-specified traveling conditions. Furthermore, in S830, the server300uses the SOC of the electric storage device230, sent from the arithmetic unit100in S730, and the data D2, read in S820, to calculate the travelable distance distribution of the other vehicles concerning the travel route described above (the distribution will be described later with reference toFIGS. 9 to 11). The travelable distance distribution of the other vehicles is calculated on the assumption that the SOC (electric power amount) of the electric storage device mounted in the other vehicles is equal to the SOC of the electric storage device230mounted in the vehicle1. The calculated travelable distance distribution of the other vehicles is sent to the arithmetic unit100. The arithmetic unit100displays the travelable distance distribution of the other vehicles on the navigation screen140(S750).

FIG. 9is a diagram conceptually showing the narrowing down of the data D2by the traveling period.FIG. 10is a diagram conceptually showing the narrowing down of the data D2by the outside air temperature. InFIGS. 9 and 10and inFIGS. 11 and 12that will be described later, the horizontal axis represents the travelable distance of the other vehicles calculated from the data D2. The vertical axis represents the number of samples (number of data pieces) of the data D2. It should be noted that the numeric values shown in these figures are only illustrative for easy understanding.

First, referring toFIG. 9, the weather conditions and road traffic conditions will be different if the traveling period is different and, therefore, there is a high possibility that the travelable distances of the vehicle will be different. The traveling period may be a season (for example, winter), a month (for example, January), or a period designated by a specific date (for example, January 1st to January 7th). In addition, when setting the traveling period using a season, it is necessary to predefine the period corresponding to each season (for example, winter is defined as a period from December 1st to February 28th).

When the traveling period of the vehicle1is not set, all data D2about the travel route of the vehicle1is used as shown in the top ofFIG. 9. Since the data D2in this case includes data, for example, under various weather conditions or road traffic conditions, the variation in the travelable distances of other vehicles also increases. In the example shown in the top ofFIG. 9, the standard deviation σ is 25 km. The median value (or the average value or the mode value) of the travelable distance is, for example, 200 km.

As shown in the middle ofFIG. 9, the number of samples of the data D2is smaller when winter is set as the traveling period than when the traveling period is not set. In addition, the travelable distance distribution of other vehicles can also change. The middle ofFIG. 9indicates that the median value of the travelable distance is shifted from 200 km to 180 km. Furthermore, the figure indicates that the variation in the travelable distance is reduced and the standard deviation σ is 10 km.

For example, as shown in the bottom ofFIG. 9, the number of samples of the data D2when the period from January 1st to January 7th is set as the traveling period becomes even smaller than when winter is set. When the traveling period is too short as in this way, the number of samples is sometimes insufficient with the result that the dispersion of the travelable distance distribution of other vehicles becomes large. Therefore, when narrowing down the data D2, it is preferable to display the travelable distance distribution of other vehicles, as shown in the middle ofFIG. 9and in the bottom ofFIG. 9, on the navigation screen140to allow the user to confirm whether the traveling period the user set is appropriate.

Referring toFIG. 10, the outside air temperature is a temperature range (for example, 0° C. to 5° C.) of the outside air of the vehicle1. Because the discharge efficiency of the electric storage device230differs according to the outside air temperature, the outside air temperature has an influence on the travelable distance. As in the description ofFIG. 9, the travelable distance distribution of other vehicles can also be changed by setting outside air temperature.

FIG. 11is a diagram conceptually showing the narrowing down of the data D2by a plurality of traveling conditions. The user can set the traveling condition using a combination of any two or more of the traveling period, outside air temperature, accelerator work, usage amount of the air conditioner250, and number of occupants to narrow down the data D2(in the example shown in the bottom ofFIG. 11, a combination of the traveling period (winter) and the outside air temperature (0° C. to 5° C.) is set).

The user confirms the travelable distance distribution of other vehicles, such as those shown inFIGS. 9 to 11, on the navigation screen140to determine whether the data D2, narrowed down by the traveling condition that is set by the user, is to be used for calculating the travelable distance of the vehicle1. The user can determine whether to use the traveling condition, which has been set, from the viewpoint of whether the number of samples of the data D2is sufficient, whether the variation is sufficiently small, or whether the travelable distance of other vehicles seems reasonable in light of the user's past experience.

Furthermore, the user may perform an operation on the navigation screen140to select an arbitrary part of the travelable distance distribution of other vehicles (touch on the navigation screen140). By doing so, only the specific data, corresponding to the selected part, may be extracted. For example, the user may select data, corresponding to the median of the travelable distance distributions of other vehicles, in a pinpoint manner.

Alternatively, the user can select data corresponding to the longest travelable distance (that is, the theoretically best data corresponding to the most effective electricity consumption) and drive the vehicle1so that the traveling distance is as close as possible to the travelable distance corresponding to the data. When specific data is selected in this manner, the traveling conditions (accelerator work, electric power consumption amount of the air conditioner, etc.) of the vehicle corresponding to the selected data may be displayed on the navigation screen140. This display allows the user to know under what traveling conditions the travelable distance was obtained. Furthermore, this display allows the user to know what kind of operation (more specifically, the setting of accelerator work and air conditioner) is to be performed in order to achieve the longest travelable distance.

For ease of understanding, the examples are described inFIGS. 9 to 11in which the travelable distance distribution of other vehicles is displayed on the navigation screen140with the travelable distance of other vehicles on the horizontal axis. Instead, when the electricity consumption data is received from the server300as in the first modification of the first embodiment (seeFIG. 5), the electricity consumption data distribution may be displayed with the electricity consumption on the horizontal axis.

Returning toFIG. 7, the arithmetic unit100determines in S760whether the user has completed the setting of traveling conditions (narrowing down of data D2). More specifically, if the user, who has confirmed the travelable distance distribution of the other vehicles displayed on the navigation screen140, determines that the traveling condition, which was set in S740, is not appropriate and if the user has performed an operation on the navigation screen140to indicate that the traveling condition is not appropriate (for example, the operation to press the “reset” button on the touch panel), the arithmetic unit100determines that setting of the traveling condition has not yet been completed (NO in S760) and the processing returns to S740. As a result, the processing of S740, S820, S830, S750, and S760is repeated until the traveling condition that is determined by the user to be appropriate is set.

On the other hand, if the user has performed an operation to indicate that the traveling condition is determined to be appropriate (for example, the operation to press the “OK” button on the touch panel), the arithmetic unit100determines that setting of the traveling condition is completed (YES in S760) and the processing proceeds to S770. In S770, the arithmetic unit100operates the navigation screen140so that the a user's operation to set the usage ratio is accepted. The usage ratio that is set is sent to the server300.

In S840, the server300reads the past data D1, regarding the travel route (recommended route) calculated in S810, from the travel history database340. The subsequent processing of S850, S860, and S780is equivalent to the processing of S230, S240, and S150in the first embodiment, respectively, and detailed description thereof will not be repeated. When the user performs the setting processing of the traveling condition repeatedly, the data D1, which was read in S840, and the latest data D2, which was last read in S820, are used for calculating the electricity consumption in S850.

When a travel route is not set as in the second modification of the first embodiment, the traveling condition can be narrowed down by the traveling area. If the traveling area differs, the travelable distance may also differ depending not only on the weather conditions but also on the terrain conditions such as whether the area is a steep sloping area (many sloping roads) or a flat area.

FIG. 12is a diagram conceptually showing the narrowing down of the data D2by the traveling area. When the data D2concerning an area within a predetermined range (for example, a range of 50 km), centered on the current position of the vehicle1, is used for calculating the travelable distance, the weather condition or the terrain condition may vary from location to location within the predetermined range. Therefore, the data D2may be narrowed down, for example, by an area narrower than the predetermined range (prefecture, state, or city, etc.) or the data D2may be narrowed down by a still narrower area (town or village). As shown in the bottom ofFIG. 12, the travelable distance distribution of the other vehicle can be shifted, and its shape can be changed, when the area X is set as the traveling area as compared to when the traveling area is not set (see the top ofFIG. 12).

As described above, according to the second embodiment, the data D2to be used for calculating the travelable distance of the vehicle1is narrowed down according to the traveling condition that is set by the user. This makes it possible to calculate the electricity consumption using only the data D2concerning a traveling condition similar to the traveling condition of the vehicle1, further improving the calculation accuracy of the travelable distance of the vehicle1as compared to the first embodiment.

Because the driving tendency differs from user to user, there may be users for whom the server300often calculates the travelable distance that is shorter, or conversely longer, than the actual travel distance (actual value) of the vehicle1. Therefore, in the first modification of the second embodiment, the processing will be described in which the server300carries out various adjustments according to the driving tendency of the user (the vehicle1).

FIG. 13is a flowchart showing the adjustment according to the driving tendency of the user. The processing shown in this flowchart is executed when a predetermined condition is satisfied, for example, after the vehicle1has reached the destination or when the electric storage device230of the vehicle1is being charged from a power supply (not shown) outside the vehicle1.

In step S910, the server300receives the travel history data on the vehicle1(data indicating the past result of the electricity consumption in all the links of the travel route in which the vehicle1actually traveled) via the communication device350. This data may be sent and received at once when the above-mentioned predetermined condition is satisfied or may be sent and received serially during the traveling of the vehicle1.

In step S920, the server300stores the current travel history data on the vehicle1, received in step S910, in the travel history database340. The server300collects and accumulates the travel history data on the vehicle1in this way every time the vehicle1travels so that the collected data is reflected on the next and subsequent data D1. The server300may use all of the collected data, or may use only a predetermined number of pieces of data, for example, based on the moving average.

In S930, for each link of the travel route of the vehicle1, the server300calculates the error (electricity consumption deviation rate) ΔE between the actual electricity consumption EACTof the vehicle1and the electricity consumption ECALcalculated in S850according to the user setting (seeFIG. 7). Furthermore, based on the electricity consumption deviation rate ΔE, the server300determines whether a deviation between the electricity consumption EACTand the electricity consumption ECALoccurs (S940).

FIG. 14is a diagram showing a method of determining the presence or absence of a deviation in the electricity consumption. InFIG. 14, the horizontal axis represents the travel route (a plurality of links) of the vehicle1. The vertical axis represents the electricity consumption deviation rate ΔE in each link.

For example, the electricity consumption deviation rate ΔE can be calculated for each link, as shown by expression (2) given below, by dividing the difference (EACT−ECAL) between the actual electricity consumption EACTof the vehicle1and the electricity consumption ECAL, calculated according to the user's operation, by the electricity consumption EACT.
ΔE=(EACT−ECAL)/EACT(2)

For the electricity consumption deviation rate ΔE, the target range (for example, the range between the target value±3%) is predetermined by experiment or simulation. For a link where the electricity consumption deviation rate ΔE is outside the target range (see the hatched portion), the server300increments the count value that indicates that a deviation between electricity consumption EACTand electricity consumption ECALhas occurred. When the count value (the number of links where a deviation in the electricity consumption has occurred) exceeds a predetermined number, or when the ratio of the count value to the total number of links exceeds a predetermined rate (“predetermined level”), it is determined that a deviation has occurred.

Returning toFIG. 13, if it is determined that a deviation between the electricity consumption EACTand the electricity consumption ECALhas not occurred (NO in S940), the server300sets the flag F1. The flag F1, if set, causes the range Z1of the median value±σ (σ is a standard deviation) of the travelable distance distribution to be displayed as shown in the top ofFIG. 9at the time the travelable distance distribution of other vehicles is displayed on the navigation screen140in S750(seeFIG. 7) when calculating the next travelable distance of the vehicle1(S960). As a result, when the vehicle1travels next time, the travelable distance distribution of other vehicles in the range corresponding to this flag F1is displayed on the navigation screen140.

On the other hand, if it is determined that a deviation between the electricity consumption EACTand the electricity consumption ECALhas occurred (YES in S940), the server300sets the flag F2for widening the range of the travelable distance distribution of other vehicles displayed on the navigation screen140(S950). For example, the range of the travelable distance distribution displayed on the navigation screen140is expanded from Z1to Z2. The range Z2is, for example, a range of the median value±2σ. This completes the series of processing.

As described above, according to the first modification of the second embodiment, the travel history data (data D1) on the vehicle1is collected and accumulated each time the vehicle1travels. Thus, the calculation accuracy of the travelable distance of the vehicle1can be further improved according to the driving tendency of the user.

In addition, when having the user narrow down the data D2, the range of the travelable distance distribution of other vehicles displayed on the navigation screen140is adjusted depending on whether the user has a driving tendency that a deviation of the electricity consumption tends to occur. For a user for whom a deviation of the electricity consumption easily occurs, a wider range of travelable distance distribution is displayed than for a user for whom a deviation of the electricity consumption does not easily occur (that is, the display range of the travelable distance distribution displayed on the navigation screen140is widened). This gives the user a wider selection range, for example, when the user selects an arbitrary portion of the travelable distance distribution of other vehicles on the navigation screen140, thus allowing the user to easily select the data D2that matches the user's driving tendency.

It is sometimes conceivable that, as the target value (target travelable distance), the user considers the travelable distance of the vehicle1calculated using the data D2narrowed down according to the traveling condition that has been set by the user himself/herself and that the user drives the vehicle1as if the driving was a game in order to achieve the target value. For example, it is conceivable that the user selects data with the longest possible traveling distance (theoretically best data corresponding to the most effective electricity consumption) as described above and that the user drives the vehicle1so that the travelable distance becomes as close as possible to the travelable distance of the selected data. In such a case, excessive air conditioning by the air conditioner250may result in a failure to achieve the target travelable distance. Therefore, in the second modification of the second embodiment, the control will be described for increasing the travelable distance of the vehicle1by reducing the electric power consumption amount of the air conditioner250. Note that this control may be executed only when the user performs a specific operation.

FIG. 15is a timing diagram showing the control for reducing the electric power consumption amount of the air conditioner250. InFIG. 15, the horizontal axis represents the elapsed time with the calculated time of the travelable distance of the vehicle1as the initial time (t0). The vertical axis represents the integrated value (electric power consumption amount) obtained by sequentially integrating the electric power consumption of the air conditioner250from the initial time.

The broken line C1indicates the integrated value of the actual electric power consumption of the air conditioner250in the current travel of the vehicle1(hereinafter also referred to as “actual electric power consumption amount”). On the other hand, the broken line C2indicates the integrated value of the electric power consumption of the air conditioner250included in the data D2narrowed down by a user operation (hereinafter also referred to as “allowable electric power consumption amount”).

When the user wants to achieve the target travelable distance, it is desirable to display a graph, such as the one shown inFIG. 15, on the navigation screen140in real time in order to make the user conscious of the electric power consumption by the air conditioner250. The integrated value of the electric power consumption by the air conditioner250may be displayed more simply, for example, by using a bar graph.

In the period to time t1, the actual electric power consumption amount is less than the allowable electric power consumption amount. When the actual electric power consumption amount reaches the allowable electric power consumption at time t1, the arithmetic unit100notifies the user that there is a possibility that the target travelable distance may not be achieved if the operation of the air conditioner250is continued at this pace. This notification may be output by displaying a message on the navigation screen140or by outputting voices from the speaker150. Upon receiving the notification, the user saves the air consumption of the air conditioner250, for example, by reducing the air volume of the air conditioner250(including by stopping the air conditioner250) at time t2. Alternatively, the air volume of the air conditioner250may be automatically reduced (or may be automatically stopped) without requiring a user operation. As a result, the actual electric power consumption amount falls below the allowable electric power consumption again (see time t3).

In the second modification of the second embodiment, visualization of the electric power consumption amount of the air conditioner250makes it possible to support a user's challenge to achieve the target travelable distance, as described above. From another point of view, even if the initial target travelable distance cannot be achieved and the error between the target travelable distance and the actual travel distance is relatively large, this visualization informs the user that the error has been caused due to a large power consumption amount of the air conditioner250. This information reduces user dissatisfaction that the calculation accuracy of the travelable distance is low.

If the user is unlikely to achieve the target travelable distance, a suggestion of accelerator work for improving the electricity consumption (message display on the navigation screen140or voice guidance) may also be provided to the user in addition to controlling the air conditioner250. Also, if the SOC of the electric storage device230is likely to be exhausted before the vehicle1reaches the destination, a notification may be provided to the user to charge the electric storage device23earlier.

In addition, if the user cannot achieve the target travelable distance, the data D1and the data D2, used by the user as the target, may be compared to analyze the cause and, then, the analysis result (for example, excessive air conditioning by the air conditioner250, too frequent overtaking, etc.) may be fed back to the user.

The first embodiment and the second embodiment, including modifications thereof, may be combined as necessary to the extent that technical inconsistency does not occur. For example, there is no technical inconsistency in adding the narrowing down of the data D2, described in the second embodiment, to the first embodiment. In addition, there is no technical inconsistency in adding the control for extending the travelable distance, described in the second modification of the second embodiment, to the first modification of the first embodiment.

It should be noted that the embodiments disclosed above are exemplary and not restrictive in all respects. The scope of the present disclosure is indicated, not by the description of the embodiments described above, but by claims, and it is intended that the meanings equivalent to, and all changes within the scope of, claims be included.