Driving assistance system

Abstract

This provides a driving assistance system that reduces the psychological burden on users regarding charging. [Solution] The system is configured to obtain the remaining energy stored in the onboard battery 8 that supplies power to the vehicle 5's drive source, or the cruising range that can be reached based on the remaining energy, and to select a candidate charging facility from among the charging facilities 10 that can charge the onboard battery 8, obtain the required energy to reach the candidate charging facility, or the cruising distance to the candidate charging facility, and simultaneously display on the display 36 either a combination of the remaining energy and the required energy, or a combination of the cruising range and the cruising distance.

Description

Technical Field

[0001] The present invention relates to a driving support device that supports charging of an in-vehicle battery.

Background Art

[0002] In recent years, in addition to gasoline vehicles driven by an engine as a driving source, there are electric vehicles driven by a motor based on electric power supplied from a battery as a driving source, hybrid vehicles that use both a motor and an engine as a driving source, and the like. As a method for charging the in-vehicle battery provided in such electric vehicles and hybrid vehicles, there are a method of charging with regenerative power of a motor generated during deceleration or during driving on a downhill road while the vehicle is running, a method of charging using a generator driven based on an engine, and in addition, a method of charging at home or at a dedicated charging facility.

[0003] Here, the number of charging facilities is smaller than that of gas stations, and if the timing of charging at a charging facility is misjudged, there is a great risk such as being unable to reach the destination. Therefore, in the above electric vehicle, it is necessary to drive while always paying attention to the current remaining energy amount and the position of the charging facility, and it has a feature of a large psychological burden on the user. Therefore, for example, in Japanese Unexamined Patent Application Publication No. 2022-7768, as a means for reducing such a psychological burden on charging, a technique for displaying, on a map image, a range that can be reached with the current remaining energy amount stored in the in-vehicle battery together with the arrival probability has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology described in Patent Document 1, the displayed map image shows the range that is likely to be reached with the current amount of remaining energy. However, it could not show, for example, when charging should be performed if the user's intended destination was not within reach. Generally, charging efficiency is better when charging is performed near the limit of the range that can be reached with the current amount of remaining energy, but charging facilities are not always available in such locations. Therefore, it was necessary for the user to check where charging facilities were located on the displayed map image and to plan their charging in advance.

[0006] The present invention was made to solve the aforementioned problems of the conventional method, and aims to provide a driving assistance device that allows users to always know how much margin they have to reach the next potential charging facility, even if they have not planned their charging in advance, thereby reducing the psychological burden on users regarding charging. [Means for solving the problem]

[0007] To achieve the above objective, the driving support device according to the present invention includes: current information acquisition means for acquiring the amount of remaining energy stored in an on-board battery that supplies power to the vehicle's drive source, or the cruising range that can be traveled based on the amount of remaining energy; necessary information acquisition means for acquiring the amount of energy required to travel to a candidate charging facility, or the distance traveled to a candidate charging facility, from among charging facilities capable of charging the on-board battery; and information display means for simultaneously displaying on a display device the combination of the remaining energy amount and the required energy amount, or the combination of the cruising range and the distance traveled. Furthermore, "simultaneously" does not necessarily mean that the display starts at the same time; it is sufficient that the display periods overlap. [Effects of the Invention]

[0008] According to the driving support device of the present invention having the above configuration, the combination of the remaining energy amount of the on-board battery and the amount of energy required to travel to a candidate charging facility, or the combination of the remaining driving range and the distance to a candidate charging facility, is displayed on the display device simultaneously. As a result, even if a charging plan is not made in advance, the user can always know how much margin they have to reach the next candidate charging facility, thereby reducing the psychological burden on the user regarding charging. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the driving support system according to this embodiment. [Figure 2] This is a block diagram showing the configuration of the driving support system according to this embodiment. [Figure 3] This is a schematic block diagram showing the control system of the communication terminal according to this embodiment. [Figure 4] This is a flowchart of the information provision processing program according to this embodiment. [Figure 5] This diagram illustrates the candidate areas and the nearest charging facilities. [Figure 6] This diagram shows the driving assistance screen displayed on the LCD display. [Figure 7] This diagram shows the transition of the nearest charging facility as the vehicle travels. [Figure 8] This figure shows the change in the amount of energy required as the nearest charging facility changes. [Modes for carrying out the invention]

[0010] Hereinafter, the driving support device according to the present invention will be described in detail with reference to the drawings, based on one embodiment in which the driving support device is implemented in a communication terminal 1. First, the schematic configuration of the driving support system 2 including the communication terminal 1 according to this embodiment will be described with reference to Figure 1. Figure 1 is a schematic configuration diagram showing the driving support system 2 according to this embodiment.

[0011] As shown in Figure 1, the driving support system 2 according to this embodiment basically comprises an information provision server 4 located in the information provision center 3, a navigation device 6 which is an in-vehicle device mounted in the vehicle 5, and a communication terminal 1 held by the user, who is an occupant of the vehicle 5. Furthermore, the information provision server 4 and the communication terminal 1 are configured to send and receive electronic data to and from each other via a communication network 7. In addition, the navigation device 6 and the communication terminal 1 are configured to send and receive electronic data to and from each other via wireless communication such as Bluetooth® or wired communication by connecting a cable. Examples of communication terminals 1 include mobile phones, smartphones, tablet terminals, personal computers, etc.

[0012] Furthermore, vehicle 5 is a vehicle equipped with at least a motor as a drive source and an on-board battery 8 as a means of supplying power to the motor, and is a vehicle capable of charging the on-board battery 8 at a charging facility. Applicable vehicles include electric vehicles (hereinafter referred to as EVs) that use only a motor as a drive source, and hybrid vehicles that use both a motor and an engine as a drive source, in particular plug-in hybrid vehicles (hereinafter referred to as PHVs).

[0013] Here, the information provision server 4 is a server device that manages the information provided to the communication terminal 1 (i.e., the user who possesses the communication terminal 1). The information provision server 4 stores information about information provision locations throughout the country that are to be provided to the communication terminal 1 in the distribution information DB 9. In this embodiment, at least information about charging facilities 10 capable of charging the vehicle battery 8 is stored in the distribution information DB 9 as an information provision location, but information about information provision locations other than charging facilities 10 (for example, commercial facilities, public facilities, parking lots, etc.) may also be stored in the distribution information DB 9. The information provision server 4 then provides (distributes) the information about information provision locations stored in the DB to the communication terminal 1 via the communication network 7.

[0014] Here, the charging facility 10 is a facility capable of charging the on-board battery 8 of the vehicle 5, and typically includes a parking space for parking the vehicle, and furthermore, charging equipment consisting of an operation panel and cables that connect to the vehicle is installed around the parking space. In addition to dedicated facilities for charging vehicles, the above-mentioned charging facility 10 may also be installed in parts of parking lots of commercial facilities such as shopping malls and service areas, car dealerships, coin-operated parking lots, etc.

[0015] Furthermore, the information provision server 4 is also connected to a charging facility management server that manages charging facilities 10 throughout the country. Through the charging facility management server, it is possible to obtain information about the charging facilities 10, such as the current availability of chargers and other information about the charging facilities 10 (for example, the number of chargers, the maximum output of the chargers, the maximum charging time, available time slots, usage fees, congestion status, compatible vehicle types, etc.).

[0016] Furthermore, the navigation device 6 is mounted in the vehicle 5 and is an in-vehicle device that displays a map of the area around the vehicle's position based on map data held by the navigation device 6 or map data acquired from an external source, displays the vehicle's current position on the map image, and provides navigation guidance along a set route. The navigation device 6 is also connected to the vehicle control ECU and battery level meter mounted in the vehicle 5 via an in-vehicle network such as CAN, and is able to acquire information regarding the on-board battery 8 (for example, the current remaining energy amount, the maximum amount of energy that can be charged per unit time for the on-board battery determined for each vehicle, and the power consumption performance, etc.), and can transmit this information to the communication terminal 1 using wireless communication such as Bluetooth or wired communication by connecting a cable.

[0017] On the one hand, the communication terminal 1 is an information terminal possessed by a user who is a vehicle occupant and equipped with communication functions, navigation functions, etc. For example, it corresponds to a mobile phone, a smartphone, a tablet terminal, a personal computer, etc. In particular, when the communication terminal 1 is a terminal capable of executing applications such as a smartphone etc., an application program is installed as one of the applications to display a map image around the current position and guide information regarding the nearest charging facility while displaying it. Incidentally, the function of guiding these charging facilities may be a part of the navigation function for guiding the movement to the destination, or may be executed by an application program different from the navigation function.

[0018] In addition, the communication network 7 includes a large number of base stations arranged across the country and a communication company that manages and controls each base station, and is configured by connecting the base stations and the communication company to each other by wire (optical fiber, ISDN, etc.) or wirelessly. Here, the base station has a transceiver (transmitter / receiver) and an antenna for communicating with the communication terminal 1. And while the base station performs wireless communication between communication companies, it becomes the end of the communication network 7 and has the role of relaying the communication of the communication terminal 1 within the range (cell) where the radio wave of the base station reaches with the information providing server 4.

[0019] Subsequently, the configuration of the information providing server 4 in the driving support system 2 will be described in more detail using FIG. 2. As shown in FIG. 2, the information providing server 4 includes a server control unit 11, a distribution information DB 9 as information recording means connected to the server control unit 11, a map information DB 14, and a server-side communication device 15.

[0020] The server control unit 11 is a control unit (MCU, MPU, etc.) that controls the entire information providing server 4, and includes an internal storage device such as a CPU 21 as an arithmetic device and a control device, a RAM 22 used as a working memory when the CPU 21 performs various arithmetic processes, a ROM 23 in which control programs etc. are recorded, and a flash memory 24 that stores the program read from the ROM 23.

[0021] Furthermore, as mentioned above, the distribution information DB9 is a storage means that stores various information, particularly regarding charging facilities located throughout the country, as locations that are the target of information provision throughout the country. Here, a "charging facility" is a facility that can charge the on-board battery 8 of a vehicle 5, and it is common for it to have a parking space for parking the vehicle, and for a charger consisting of an operation panel and cables that connect to the vehicle to be installed around the parking space. In addition to facilities dedicated to charging vehicles, the above chargers may also be installed in parts of parking lots of commercial facilities such as shopping malls, car dealerships, coin parking lots, etc.

[0022] Here, information specifically regarding the charging facility is stored, including the facility ID, facility name (or the name of the other facility if it is located within a larger facility), location of the charging facility, number of chargers, maximum charger output, available hours, usage fee, and maximum charging time. This information can be obtained from a management server that manages the charging facility, and real-time congestion status can also be obtained as information about the charging facility. Note that the "maximum charging time" indicates the maximum time that can be charged in a single charge at the charging facility, and even if the onboard battery 8 is not fully charged, charging cannot be continued beyond the maximum time.

[0023] Furthermore, the map information DB14 is a storage means in which map information is stored. Map information consists of various types of information necessary for route searching, route guidance, and map display, including road networks. For example, it consists of link data related to roads (links), node data related to node points, intersection data related to each intersection, location data related to facilities and other points, map display data for displaying maps, search data for searching for routes, and search data for searching for locations.

[0024] Furthermore, when the server control unit 11 receives a route search request from the communication terminal 1, it can also perform a route search from the departure point to the destination using the map information stored in the map information DB 14. Specifically, when a destination is set in the communication terminal 1, the communication terminal 1 sends the information necessary for route search, such as the departure point and destination, to the information provision server 4 along with the route search request. The information provision server 4, upon receiving the route search request, performs a route search using the map information it possesses and identifies a recommended route from the departure point to the destination. It then sends the identified recommended route to the requesting communication terminal 1. The communication terminal 1 then sets the received recommended route as the guidance route and provides travel guidance according to the guidance route. As a result, even if the map information possessed by the communication terminal 1 is an older version, or if the communication terminal 1 does not possess any map information at all, it is possible to set an appropriate guidance route based on the latest version of map information possessed by the information provision server 4. In particular, in this embodiment, it is also possible to search for a recommended route from the vehicle's current location to a candidate charging facility for the next charging.

[0025] However, if the communication terminal 1 has map information, the above route search process can be performed on the communication terminal 1 instead of the information provision server 4. Alternatively, the above route search process may be performed on another server that has map information instead of the information provision server 4. In that case, the map information DB 14 is not necessarily required on the information provision server 4.

[0026] On the other hand, the server-side communication device 15 is a communication device for communicating with the communication terminal 1, which is the target of information transmission and reception, via the communication network 7. In addition to the communication terminal 1, it is also possible to receive traffic information consisting of various types of information such as congestion information, regulation information, and traffic accident information transmitted from the Internet network and traffic information centers, such as VICS (registered trademark: Vehicle Information and Communication System) centers.

[0027] Next, the general configuration of the communication terminal 1 owned by the user will be explained using Figure 3. Figure 3 is a schematic block diagram showing the control system of the communication terminal 1 according to this embodiment. In the following explanation, we will use the case where the communication terminal 1 is a smartphone as an example.

[0028] As shown in Figure 3, the communication terminal 1 is configured by connecting the following to the data bus BUS: a CPU 31, a memory 32 that stores user information (user ID, name, etc.) and application programs related to the user who possesses the communication terminal 1, an input / output unit 35 which is an interface for a microphone 33 and a speaker 34, a display 36 which is made up of a liquid crystal display panel, an input operation unit 37 which is made up of a touch panel and a keyboard, a GPS 38, a transmit / receive circuit unit (RF) 39 which sends and receives signals to and from base stations of the communication network 7, and a BT communication device 40 for Bluetooth communication.

[0029] Here, the CPU 31 built into the communication terminal 1 is a control means for the communication terminal 1 that performs various operations according to the operation program stored in the memory 32, and together with the memory 32, constitutes the communication terminal control unit 41. Furthermore, the various processing contents of the communication terminal control unit 41 are displayed on the display 36 as needed. The communication terminal control unit 41 also constitutes various means as processing algorithms. For example, the current information acquisition means acquires the amount of remaining energy stored in the on-board battery 8 that supplies power to the vehicle's drive source, or the cruising range that can be driven based on the amount of remaining energy. The necessary information acquisition means targets candidate charging facilities among the charging facilities that can charge the on-board battery 8, and acquires the amount of energy required to drive to the candidate charging facility, or the driving distance to the candidate charging facility. The information display means simultaneously displays on the display 36 either the combination of the remaining energy amount and the required energy amount, or the combination of the cruising range and the driving distance. The guidance means, when the charging facility candidate switches to a new charging facility due to a change in the vehicle's current position or direction of travel, and the remaining energy is insufficient to cover the required energy to travel to the new charging facility candidate, will guide the vehicle to continue charging at the previous charging facility candidate. In other words, the communication terminal control unit 41 is an example of a current information acquisition means, a necessary information acquisition means, an information display means, and a guidance means.

[0030] Furthermore, the communication terminal 1 can communicate via the transmitting and receiving circuit unit 39, enabling it to perform not only voice calls but also internet communication, receive information about charging facilities from the information provision server 4, and receive traffic information consisting of various types of information such as congestion information, regulation information, and traffic accident information transmitted from traffic information centers, such as VICS (registered trademark) centers and probe centers.

[0031] Furthermore, memory 32 is a storage medium that stores user information (user ID, name, etc.) and map information related to the user who possesses the communication terminal 1, as well as the user's web browsing history, the user's movement history which is a history of location information detected based on GPS 38 and other sensors, and schedule information. Various application programs, including the information provision processing program (Figure 4) described later, are also stored. Memory 32 may also be configured as a hard disk, memory card, etc.

[0032] Furthermore, memory 32 also stores identification information necessary for communication via Bluetooth (such as the BT address).

[0033] In addition to outputting voice for phone calls, the speaker 34 also outputs voice guidance that directs the user along a designated route (the user's planned travel route) based on instructions from the communication terminal control unit 41 when the navigation function is running.

[0034] Furthermore, the display 36 is a type of display device, mounted on one side of the housing, and may be a liquid crystal display or an organic EL display. It displays the top screen for executing various applications installed on the communication terminal 1, screens related to the executed application (internet screen, email screen, navigation screen, etc.), and various information such as images and videos. In particular, in this embodiment, in addition to a map image of the user's current location, information about potential charging facilities is also displayed.

[0035] Furthermore, the input operation unit 37 is composed of a touch panel located on the front of the display 36 and hard buttons located on the casing. The communication terminal control unit 41 controls the system to perform various operations based on electrical signals output by pressing the touch panel or hard buttons. The input operation unit 37 can also be composed of various keys such as number / character input keys, cursor keys to move the cursor for selecting displayed content, and a confirmation key to confirm the selection.

[0036] Furthermore, the GPS38 can detect the current location and time of the communication terminal 1 (i.e., the user) by receiving radio waves generated by artificial satellites. In addition to the GPS38, the system may also be configured to include other devices (such as a gyro sensor) for detecting the current location and orientation of the communication terminal 1.

[0037] Furthermore, the transmitting / receiving circuit section 39 is a circuit section for transmitting and receiving signals to and from base stations of the communication network 7 using communication standards such as 3G, 4G, and LTE.

[0038] Furthermore, the BT communication device 40 is a module for performing wireless communication via Bluetooth. The communication terminal 1 communicates with the navigation device 6 and other devices within the communication range via Bluetooth wireless communication through the BT communication device 40.

[0039] Next, the information provision processing program executed in the communication terminal 1 having the above configuration will be described with reference to Figure 4. Figure 4 is a flowchart of the information provision processing program according to this embodiment. Here, the information provision processing program is executed in the communication terminal 1 after a predetermined application program is started, and is a program that guides the user to information about candidate charging facilities for charging the vehicle they are riding in. The program shown in the flowchart in Figure 4 below is stored in the memory 32 of the communication terminal 1 and executed by the CPU 31.

[0040] Furthermore, in the following explanation, it is assumed that the user possessing the communication terminal 1 is riding in a vehicle 5 equipped with an on-board battery 8 as a means of supplying power to the motor, which is the drive source. In other words, the current location of the communication terminal 1 corresponds to the current location of the user and the vehicle 5. It is also assumed that the communication terminal 1 has established communication with the navigation device 6 installed in the vehicle 5, and is in a state where it can obtain information about the vehicle 5 in which the user is riding.

[0041] First, in step 1 (hereinafter abbreviated as S), the CPU 31 starts a predetermined application program (hereinafter referred to as the charging app) for providing information about charging facilities. The charging app may be started automatically not only when the user performs a predetermined operation on the communication terminal 1, but also when the vehicle starts moving or when it connects to the navigation device 6. Furthermore, if providing information about charging facilities is a function of the navigation app, the startup of the navigation app is considered the startup of the charging app. The charging app can be started before the user begins moving towards their destination, or after they have started moving towards their destination. It is assumed that the charging app has been downloaded from a web server or the like and installed on the communication terminal 1 in advance.

[0042] Next, in S2, the CPU 31 obtains the current SOC value (remaining energy of the onboard battery 8) for the vehicle 5 in which the user is riding. The SOC value is obtained from the navigation device 6 via wireless communication such as Bluetooth. Meanwhile, the navigation device 6 can obtain this information from the vehicle control ECU and battery level meter installed in the vehicle 5 via an onboard network such as CAN.

[0043] Next, in S3, the CPU 31 searches for charging facilities around the vehicle's current location (which is also the current location of the user and communication terminal 1). For example, it searches for charging facilities within a 10km radius centered on the vehicle's current location. Map information and location information of charging facilities necessary for searching for charging facilities can be obtained from the information provision server 4. Alternatively, the search for candidate charging facilities in S3 may be performed by the information provision server 4 instead of the communication terminal 1, and the communication terminal 1 may obtain the search results from the information provision server 4. Furthermore, if a guidance route to the destination is set in the navigation device 6 or communication terminal 1, the search may be limited to charging facilities along the guidance route or within a predetermined distance (e.g., 300m) from the guidance route. Charging facilities that are closed or have no available charge may also be excluded from the search. The operating hours and congestion status of charging facilities can be obtained from the information provision server 4.

[0044] Subsequently, in S4, the CPU 31 selects a candidate charging facility from among the charging facilities around the vehicle's current location, as searched in S3, which is a candidate charging facility where the vehicle will next charge its onboard battery 8. In this embodiment, the candidate charging facility is the charging facility closest to the vehicle (hereinafter referred to as the nearest charging facility 46) that is located within an area (hereinafter referred to as the candidate area 45) set based on the vehicle's current location and direction of travel.

[0045] To explain candidate area 45 in more detail, as shown in Figure 5, candidate area 45 is a sector-shaped area within a predetermined distance (e.g., 10 km) from the current position of vehicle 5, with a central angle θ set toward the direction of travel of vehicle 5. The value of the central angle θ can be set as appropriate, but for example, it is set to 90 degrees. The value of the central angle θ may also be changed depending on the current SOC value. For example, if the SOC value is high, it can be set to be narrower, and if the SOC value is low, it can be set to be wider in order to increase the number of charging facility candidates.

[0046] For example, in the example shown in Figure 5, there are four charging facilities 10 labeled 'A' to 'D' around the current location of vehicle 5, and of these, charging facilities 'A' and 'B' are located in the candidate area 45. When comparing charging facility 'A' 10 and charging facility 'B' 10, charging facility 'B' 10, which is the closest to vehicle 5, becomes the nearest charging facility 46. The nearest charging facility 46 can be determined by comparing the straight-line distance from the vehicle's current location to each charging facility 10, or by comparing the distance along the road (link). The nearest charging facility 46 is not fixed; if the vehicle travels and its current location and direction of travel change, the nearest charging facility 46 will also change accordingly (S9, S10). Information identifying the currently selected nearest charging facility 46 is stored in memory 32, etc.

[0047] Next, in S5, the CPU 31 calculates the amount of energy (hereinafter referred to as the required energy) to travel to the nearest charging station 46 that is currently selected. In calculating the required energy, the CPU first searches for a recommended route from the vehicle's current location to the nearest charging station 46. The recommended route search may be performed by the communication terminal 1 or by an external server such as the information provision server 4. For example, if the search is performed by the information provision server 4, the communication terminal 1 sends the information provision server 4 with the route search request along with the vehicle's current location and the information necessary for the route search, such as the nearest charging station 46. The information provision server 4, upon receiving the route search request, uses its map information to perform a route search and identifies a recommended route from the vehicle's current location to the nearest charging station 46. After that, it sends the identified recommended route to the requesting communication terminal 1. Next, the CPU 31 calculates the amount of energy (kWh) that would be consumed if the vehicle were to travel to the nearest charging station 46 following the searched recommended route, and this is the required energy. Furthermore, when calculating the required energy amount, it is desirable to consider not only the route length of the recommended route from the vehicle's current location to the nearest charging facility 46, but also the route gradient, traffic information, and the vehicle's driving history. In addition, the CPU 31 may obtain the vehicle's energy consumption (the distance that can be traveled per unit amount of energy estimated from past driving history) from the navigation device 6 and use that energy consumption for the calculation.

[0048] Subsequently, in S6, the CPU 31 simultaneously displays the current SOC value obtained in S2 and the required energy amount calculated in S5 on the display 36. Figure 6 shows the driving guidance screen displayed on the display 36 of the communication terminal 1 after the charging application is launched in S1. The driving guidance screen will continue to be displayed until the charging application is closed or the vehicle finishes driving.

[0049] As shown in Figure 6, the driving guidance screen displays a map image 51 of the area around the vehicle's current location and a vehicle position marker 52 indicating the vehicle's current location. If a destination is set, the guidance route to the destination is also displayed as needed. The driving guidance screen also displays a battery level meter 53 and a required energy meter 54. The battery level meter 53 is a bar graph meter that shows the current remaining energy amount (SOC value) relative to the maximum charge amount of the onboard battery 8. The user can understand the current SOC value by looking at the battery level meter 53. The required energy meter 54 is also a bar graph meter that shows the required energy amount calculated in S5, and is displayed on the same scale as the battery level meter 53. In other words, the driving guidance screen displays a battery level meter 53 (first line segment) whose length changes according to the amount of remaining energy, and a required energy meter 54 (second line segment) whose length changes according to the amount of energy needed. By comparing the length of the battery level meter 53 and the required energy meter 54, the user can compare the current SOC value with the amount of energy needed to reach the nearest charging facility 46. Specifically, if the length of the battery level meter 53 is longer than the length of the required energy meter 54, the user can understand that they can travel to the nearest charging facility 46 with the current SOC value. Furthermore, the difference in meter lengths also allows the user to understand how much margin of safety they have to travel to the nearest charging facility 46 with the current SOC value. It is desirable that the battery level meter 53 and the required energy meter 54 be displayed adjacent to each other with their axis origins aligned to facilitate comparison.

[0050] As a result, by visualizing the battery level meter 53 and the required power meter 54 displayed on the display 36, users can always know how much margin they have before reaching a potential charging facility, even if they haven't planned their charging in advance. This reduces the psychological burden on users regarding charging.

[0051] Next, in S7, the CPU 31 compares the current SOC value obtained in S2 with the required energy amount calculated in S5, and determines whether the difference between the current SOC value and the required energy amount is below a threshold. The threshold is, for example, 5% or 10% of the maximum capacity of the vehicle battery 8.

[0052] Then, if it is determined that the difference between the current SOC value and the required energy amount is below the threshold (S7:YES), the system proceeds to S8. On the other hand, if it is determined that the difference between the current SOC value and the required energy amount is greater than the threshold (S7:NO), the system proceeds to S9. Furthermore, if it is determined that the required energy amount is greater than the current SOC value, the system will inform the user that it will be difficult to reach the nearest charging facility 46.

[0053] In S8, the CPU 31 advises the user to charge at the nearest charging station 46 because the SOC value does not have sufficient margin for the required energy. For example, it may display a message such as "Please charge your battery at ○○ (name of the nearest charging station 46)" on the display 36, or output an audio guidance from the speaker 34. Furthermore, it is also possible to display information about the nearest charging station 46 on the display 36, or to provide driving guidance with the nearest charging station 46 set as the destination. The process then proceeds to S14.

[0054] Meanwhile, in S9, the CPU 31 determines whether the currently selected nearest charging station 46 is located outside the candidate area 45. As mentioned above, the range of the candidate area 45 is determined by the current position and direction of travel of the vehicle 5 (Figure 5). Therefore, as shown in Figure 7, if the current position and direction of travel of the vehicle 5 change as the vehicle 5 moves, the range included in the candidate area 45 also changes, and a charging station 10 that was located inside the candidate area 45 may move outside the candidate area 45, or conversely, a charging station 10 that was located outside the candidate area 45 may move inside the candidate area 45. For example, the example shown in Figure 7 shows an instance where the charging station 10 labeled 'B', which was the nearest charging station 46, moved outside the candidate area 45 as the vehicle moved.

[0055] If it is determined that the currently selected nearest charging station 46 is located outside the candidate area 45 (S9:YES), the process proceeds to S10. On the other hand, if it is determined that the currently selected nearest charging station 46 remains within the candidate area 45 (S9:NO), the process proceeds to S14.

[0056] In S10, the CPU 31 selects a new nearest charging station 46 because the currently selected nearest charging station 46 is located outside the candidate area 45. Further details are the same as in S4, so the explanation is omitted.

[0057] Subsequently, in S11, the CPU 31 calculates the amount of energy required to travel to the nearest charging facility 46, which was newly selected in S10. The details are the same as in S5, so the explanation is omitted.

[0058] Furthermore, if the nearest charging station 46 changes to another charging station, the required energy meter 54 displayed on the display 36 is switched to display for the new nearest charging station 46. In other words, when the nearest charging station 46 changes to another charging station, the CPU 31 displays the amount of energy required to travel to the newly selected nearest charging station 46 as the required energy meter 54. This makes it possible to update the display content of the display 36 in accordance with the change in the nearest charging station 46.

[0059] Next, in S12, the CPU 31 compares the current SOC value with the required energy amount newly calculated in S11 and determines whether the required energy amount is greater than the current SOC value. Here, as shown in Figure 8, if the nearest charging facility 46 changes to another charging facility, depending on the location of the new nearest charging facility 46, it is possible that the required energy amount was less than the current SOC value at the nearest charging facility 46 before the change, but may be greater at the nearest charging facility 46 after the change.

[0060] If it is determined that the required energy amount is greater than the current SOC value (S12: YES), the process proceeds to S13. On the other hand, if it is determined that the required energy amount is less than the current SOC value (S12: NO), the process proceeds to S14.

[0061] In S13, the CPU 31 informs the user that it will be difficult to reach the newly selected nearest charging station 46 with the current SOC value, and encourages the user to charge at the previous nearest charging station 46. For example, it may display a message such as "Please charge your battery at ○○ (name of the previous nearest charging station 46)" on the display 36, or output an audio guidance from the speaker 34. Furthermore, it is also possible to display information about the previous nearest charging station 46 on the display 36, or to provide driving guidance with the previous nearest charging station 46 as the destination. The process then proceeds to S14.

[0062] In S14, the CPU 31 determines whether vehicle 5 has finished driving. It may also determine whether to terminate the charging application.

[0063] Then, if it is determined that vehicle 5 has finished its journey (S14: YES), the information provision processing program is terminated. On the other hand, if it is determined that vehicle 5 has not finished its journey (S14: NO), the program returns to S6 and continues to provide information about charging facilities.

[0064] Furthermore, in the above-mentioned information provision processing program (Figure 4), in S6, the combination of the remaining energy amount (SOC value) of the onboard battery 8 and the amount of energy required to travel to the nearest charging facility 46 is simultaneously displayed on the display 36. However, instead, the combination of the "possible driving range" based on the remaining energy amount of the onboard battery 8 and the "driving distance" to the nearest charging facility 46 may be simultaneously displayed on the display 36. In that case, in S2, the CPU 31 calculates the possible driving range from the current SOC value, and in S5, it obtains the driving distance from the vehicle's current position to the nearest charging facility 46. The possible driving range is calculated using, for example, the vehicle's energy consumption (distance that can be traveled per unit amount of energy estimated from past driving history) obtained from the navigation device 6. On the other hand, the driving distance may be the distance along the road (link), or the distance along the recommended route from the vehicle's current position to the charging facility 46.

[0065] Furthermore, it is desirable to display the remaining range and driving distance as bar graphs on a meter, as shown in Figure 6, and to display them on the same scale. It is also desirable to align the origin of the axes and display them adjacent to each other. Since a meter whose length changes according to the length of the remaining range (third line segment) and a meter whose length changes according to the length of the driving distance (fourth line segment) are displayed, the user can compare the length of each meter to compare the remaining range that can be driven at the current SOC value with the driving distance to the nearest charging facility 46.

[0066] Furthermore, even when the combination of remaining range and driving distance is displayed on the display 36 as described above, the user can always be aware of how much margin they have before reaching the next potential charging station, thereby reducing the user's psychological burden regarding charging.

[0067] As described in detail above, the communication terminal 1 and the computer program executed on the communication terminal 1 according to this embodiment acquire the amount of remaining energy stored in the on-board battery 8 that supplies power to the drive source of the vehicle 5, or the cruising range that can be traveled based on the amount of remaining energy (S2), and acquire the amount of energy required to travel to a candidate charging facility, or the driving distance to a candidate charging facility, from among the charging facilities 10 that can charge the on-board battery 8 (S5), and simultaneously display on the display 36 either the combination of the remaining energy amount and the required energy amount, or the combination of the cruising range and the driving distance (S6). As a result, even if a charging plan is not made in advance, the user can always know how much margin is left before reaching the next candidate charging facility, and the psychological burden on the user regarding charging can be reduced. Furthermore, when displaying the combination of remaining energy and required energy, a first line segment whose length changes according to the amount of remaining energy and a second line segment whose length changes according to the amount of required energy are displayed simultaneously. When displaying the combination of remaining range and driving distance, a third line segment whose length changes according to the length of the remaining range and a fourth line segment whose length changes according to the length of the driving distance are displayed simultaneously (S6). Therefore, by looking at the difference in the lengths of the line segments, it is easy to understand how much margin is available to reach a potential charging facility based on the current SOC value. Furthermore, the candidate charging facilities are the nearest charging facilities 46 located within the candidate area 45 set based on the current position and direction of travel of the vehicle 5, and are the closest charging facilities to the vehicle 5. When the nearest charging facility 46 changes to a new charging facility due to a change in the current position or direction of travel of the vehicle 5, the display switches to show the new nearest charging facility 46 (S6). This makes it possible to update the display content to reflect the change in charging facilities even if the charging facility to be charged next changes due to a change in the vehicle's current position or direction of travel. Furthermore, if the charging facility candidate switches to a new charging facility due to a change in the vehicle's current position or direction of travel, and the remaining energy is insufficient to cover the distance to the new charging facility candidate (S12: YES), the vehicle will be instructed to charge at the previous charging facility candidate (S13), thereby preventing the vehicle from being unable to reach a charging facility.

[0068] It should be noted that the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention. For example, in this embodiment, the driving guidance screen in Figure 6 displays the current SOC value and the amount of energy required to reach the nearest charging station 46. However, if there are other potential charging stations besides the nearest one 46, the required energy amounts for multiple charging stations may be displayed. For example, the required energy amounts for up to three charging stations, ordered by proximity to the vehicle's current location, may be displayed. The same applies if the driving distance to the candidate charging stations is displayed instead of the required energy amount.

[0069] Furthermore, in this embodiment, the current SOC value and the amount of energy required to reach the nearest charging facility 46 are displayed as a bar graph meter on the driving guidance screen in Figure 6. However, if the user can understand the current SOC value and the amount of energy required, they may be displayed in a different format. For example, they may be displayed as a pie chart or as specific numerical values. The same applies when displaying the remaining driving range and the distance traveled.

[0070] Furthermore, although this embodiment describes an example where the communication terminal 1 is applied to a smartphone, it can also be applied to other types of communication terminals as long as they have communication functions with the vehicle and the information provision server 4. For example, it can be applied to mobile phones, tablet terminals, personal computers, etc. Also, the in-vehicle navigation device 6 may also function as the communication terminal 1, or other in-vehicle devices or vehicle control ECUs may perform processing in place of the communication terminal 1.

[0071] Furthermore, in this embodiment, in the information provision processing program shown in Figure 7, the communication terminal 1 was the main entity executing the processes related to searching for the nearest charging facility 46 and comparing and determining the amount of energy (S3-S5, S7, S9, S10-S12). However, the information provision server 4 may also perform some or all of these processes. In other words, it is also possible to apply the present invention to a system including the communication terminal 1 and the information provision server 4. [Explanation of Symbols]

[0072] 1...Communication terminal (driving support device), 2...Information provision system, 4...Information provision server, 5...Vehicle, 6...Navigation device, 8...Onboard battery, 9...Distribution information DB, 10...Charging facility, 31...CPU, 32...Memory, 36...Display (display device), 41...Communication terminal control unit (example of current information acquisition means, necessary information acquisition means, information display means, guidance means), 45...Candidate area, 46...Nearest charging facility (charging facility candidate), 53...Battery level meter (first line segment, third line segment), 54...Required power meter (second line segment, fourth line segment)

Claims

1. A current information acquisition means that acquires the amount of remaining energy stored in the on-board battery that supplies power to the vehicle's drive source, or the driving range that can be achieved based on the amount of remaining energy, A means for acquiring necessary information, which targets a candidate charging facility among the charging facilities capable of charging the vehicle battery, and acquires the amount of energy required to travel to the candidate charging facility, or the distance traveled to the candidate charging facility. A driving support device having information display means that simultaneously displays on a display device the target of either the combination of the remaining energy amount and the required energy amount, or the combination of the cruising range and the driving distance.

2. The aforementioned information display means is When displaying the combination of the remaining energy and the required energy, a first line segment whose length changes according to the magnitude of the remaining energy and a second line segment whose length changes according to the magnitude of the required energy are displayed simultaneously. The driving support device according to claim 1, which, when displaying the combination of the cruising range and the driving distance, simultaneously displays a third line segment whose length changes according to the length of the cruising range and a fourth line segment whose length changes according to the length of the driving distance.

3. The candidate charging facility is located within an area defined based on the vehicle's current position and direction of travel, and is the charging facility closest to the vehicle. The driving support device according to claim 1, wherein the information display means switches to a display targeting the new charging facility candidate when the charging facility candidate switches to a new charging facility due to a change in the vehicle's current position or direction of travel.

4. The driving support device according to claim 3, which has a guidance means for guiding the vehicle to continue charging at the charging facility candidate before the switch if the candidate charging facility switches to a new charging facility due to a change in the vehicle's current position or direction of travel, and the remaining energy amount is insufficient to meet the energy requirements for traveling to the new candidate charging facility.

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