Navigation Device

Abstract

To provide a navigation device with which it is possible to compare costs of search branches even in the middle of a route search, with toll road charges taken into account.SOLUTION: The navigation device comprises: a destination setting unit 30 for setting a destination; a map data storage device 3 for storing map data that includes a first cost as a passage time regarding each of a plurality of links corresponding to a road; a map buffer 10; and a route search processing unit 22 which, when searching for a travel route to the destination on the basis of the stored map data, adds a second cost corresponding to a use charge of a toll road to the first cost and searches for a travel route, and determines a travel route whose total cost way up to the destination is lowest. When each of a plurality of search branches which are to be compared includes a common toll road differing in entrance, the route search processing unit 22 sets a second cost using a use charge up to an exit that is subsequently reached in this common toll road.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a navigation device that searches for a driving route to a destination. [Background technology]

[0002] Conventionally, there has been known a navigation device that performs a route search to create pairs by exhaustively searching IN-side toll gate nodes and OUT-side toll gate nodes, calculates the toll road tolls for all pairs, calculates the total cost between the departure point and destination when the toll roads of all pairs are used, and identifies the route with the lowest cost from among the calculated costs (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-134191 A Summary of the Invention [Problem to be solved by the invention]

[0004] In general, route searches in navigation devices involve expanding search branches one by one, adopting the route with the lowest cost each time, and ultimately identifying the least-cost route between the departure point and the destination.

[0005] However, tolls for expressways and the like cannot be calculated until the entrance and exit ICs are determined, so when multiple routes with different entrance ICs overlap, the toll from the first entrance IC to the second entrance IC cannot be determined, making it impossible to make a cost comparison that takes the toll into account. Therefore, when there is a first route that goes via an expressway to the second entrance IC, and a second route that goes via a general road to the second entrance IC, the toll for the expressway included in the first route cannot be determined, making it impossible to make a cost comparison that takes this toll into account.

[0006] The present invention was created in light of these circumstances, and its purpose is to provide a navigation device that can compare the costs of search branches, taking into account toll road (expressway) charges, even in the middle of route search. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the navigation device of the present invention comprises a destination setting means for setting a destination, a map data storage means for storing map data including a first cost as a passing time for each of a plurality of links corresponding to roads, and a route search means for, when searching for a driving route to the destination based on the map data stored in the map data storage means, adding a second cost corresponding to a toll for using a toll road to the first cost to search for a driving route and determining a driving route with the lowest total cost to reach the destination, and the route search means repeats a process of selecting a search branch with the lowest cost from a plurality of search branches to be compared in cost until the destination, and when each of the plurality of search branches to be compared includes a common toll road with different entrances, sets the second cost using the toll for a subsequent exit on this common toll road.

[0008] This allows you to set the toll fees for toll roads included in the multiple search branches to be selected and compare the costs of these multiple search branches, making it possible to compare the costs of search branches taking toll road (expressway) fees into account even in the middle of route search.

[0009] In addition, the above-mentioned exits are connected to a common toll road. along the running direction First arriving exit is This makes it easier to identify the sections of toll roads for which toll fees are to be calculated, and reduces the processing burden of route searches.

[0010] It is also desirable that the second cost has a value proportional to the toll, so that the cost according to the toll can be reflected in the route search, making it possible to determine whether it is worth paying the toll to use the toll road.

[0011] It is also preferable that a shortened time corresponding to the above-mentioned usage fee is set, and the route search means selects a search branch including a toll road when the travel time can be shortened by more than the shortened time by selecting this option. Alternatively, it is preferable that an allowable fee that can be paid to shorten a predetermined time is set, and the route search means calculates the shortened time of the travel time by selecting a search branch including a toll road, and selects this option when the usage fee of the toll road is cheaper than the allowable fee corresponding to this shortened time. This makes it possible to search for a route that associates the usage fee with the shortened time.

[0012] It is also desirable that the above-mentioned time saving and allowable charge can be changed by the user, which enables route search that reflects the allowable charge for time saving for each user. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a navigation device according to an embodiment. [Diagram 2] 13 is a flowchart showing an operational procedure for performing a route search. [Diagram 3] This is an explanatory diagram of two search branches that include toll roads with different entrances. [Figure 4] FIG. 13 is a diagram showing a specific example of a cost comparison that reflects highway tolls. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a navigation device according to an embodiment of the present invention will be described with reference to the drawings.

[0015] Fig. 1 is a diagram showing the configuration of a navigation device according to an embodiment. The navigation device shown in Fig. 1 includes a navigation controller 1, a map data storage device 3, an operation unit 4, a vehicle position detection unit 5, a display unit 6, and an audio unit 7. This navigation device is mounted on a vehicle.

[0016] The navigation controller 1 executes a predetermined operation program using a CPU, ROM, RAM, etc., to realize various functions such as displaying a map image of the area around the vehicle's position, searching for facilities, and searching and guiding routes. The detailed configuration of the navigation controller 1 will be described later.

[0017] The map data storage device 3 is a storage medium that stores map data required for map display, facility search, route search, route guidance, etc., and a device that reads the storage medium. The map data storage device 3 stores map data in units of rectangular sheets that are divided into appropriate sizes by longitude and latitude. The map data for each sheet can be specified and read by specifying the sheet number. The map data storage device 3 is realized by a hard disk device or semiconductor memory, or by a DVD and a device that reads the DVD. The map data storage device 3 may also be replaced with a communication device to obtain required data from an external map distribution server (not shown) or the like.

[0018] The operation unit 4 is for receiving instructions (operations) from the user, and is equipped with various operation buttons and operation knobs. The operation unit 4 also includes a touch panel attached to the screen of the display device 6, and allows the user to give operation instructions by directly pointing at a part of the screen with a finger or the like. The vehicle position detection unit 5 is equipped with, for example, a GPS receiver, a direction sensor, a distance sensor, etc., and detects the vehicle position (longitude, latitude) at a predetermined timing and outputs the detection result.

[0019] The display device 6 is configured, for example, by an LCD (liquid crystal display device), and displays a map image of the vicinity of the vehicle's position, a driving route to the destination, enlarged guide images at branching points, etc., based on a video signal output from the navigation controller 1. The audio unit 7 outputs guidance voices, etc., generated based on an audio signal input from the navigation controller 1, into the vehicle cabin.

[0020] Next, we will explain the detailed configuration of the navigation controller 1. The navigation controller 1 shown in Fig. 1 includes a map buffer 10, a map readout control unit 12, a map drawing unit 14, a vehicle position calculation unit 20, a route search processing unit 22, a search condition setting unit 24, a route guidance processing unit 28, a destination setting unit 30, an input processing unit 50, and a display processing unit 60.

[0021] The map buffer 10 temporarily stores the map data read from the map data storage device 3. The map read control unit 12 outputs a read request for map data of a predetermined range to the map data storage device 3 according to the vehicle position calculated by the vehicle position calculation unit 20 or a position specified by the user operating the operation unit 4. The map drawing unit 14 performs drawing processing required for displaying a map image on the display device 6 based on the map data stored in the map buffer 10, and creates map image drawing data.

[0022] The vehicle position calculation unit 20 calculates the vehicle position based on the detection data output from the vehicle position detection unit 5, and performs a map matching process to correct the vehicle position if the calculated vehicle position is not on a road in the map data.

[0023] The route search processing unit 22 performs route search processing to search for a driving route (guided route) that connects a departure point and a destination in accordance with predetermined search conditions.

[0024] The search condition setting unit 24 sets search conditions for a route search by the route search processing unit 22, and changes them in response to a user's instruction. In this embodiment, various settings and changes are made regarding the usage fees for expressways as toll roads.

[0025] The route guidance processing unit 28 performs route guidance processing to guide the vehicle along the travel route obtained by the route search processing unit 22 by display and audio.

[0026] The destination setting unit 30 sets a destination required for the route search process performed by the route search processing unit 22. For example, a facility extracted by a search performed by a facility search unit (not shown) may be set as the destination, or a point on a map image that is directly specified by the user through the operation unit 4 may be set as the destination.

[0027] The input processing unit 50 outputs commands to each unit within the navigation controller 1 for carrying out operations corresponding to various operational instructions input from the operation unit 4.

[0028] The display processing unit 60 receives map image drawing data created by the map drawing unit 14, and displays a map image of a predetermined range on the screen of the display device 6 based on this drawing data. When drawing data showing a guide image created by the route guidance processing unit 28 is received, the display processing unit 60 displays this image on the screen of the display device 6 by superimposing it on the map image.

[0029] The above-mentioned destination setting unit 30 corresponds to a destination setting means, the map data storage device 3 and the map buffer 10 correspond to a map data storage means, and the route search processing unit 22 corresponds to a route search means.

[0030] The navigation device of this embodiment has the above-mentioned configuration, and its operation will now be described.

[0031] 2 is a flow chart showing the operation procedure for performing a route search. After the navigation device is started and starts displaying a map image of the surroundings of the vehicle position, the route search processing unit 22 judges whether or not a destination has been set by the destination setting unit 30 (step 100). If a destination has not been set, a negative judgment is made, and this judgment is repeated. Also, if a destination has been set, a positive judgment is made in the judgment of step 100.

[0032] Next, the route search processing unit 22 judges whether or not a route search instruction has been given (step 102). If no instruction has been given, a negative judgment is made, and this judgment is repeated. If an instruction has been given, a positive judgment is made in the judgment of step 102.

[0033] Next, the route search processing unit 22 displays selectable search conditions (step 104). For example, when a route search is instructed using the touch panel of the operation unit 4, each search condition such as "time priority," "general road priority," "toll road priority," and "road toll reflection" are displayed in the form of a pull-down menu. Among these, "road toll reflection" is a search condition that reflects a cost proportional to the toll of a toll road in the route search, and the method of this reflection will be described later.

[0034] Next, the route search processing unit 22 judges whether or not the search condition "reflecting road tolls" has been selected (step 106). For example, if the user operates the touch panel of the operation unit 4 to select "reflecting road tolls" from the pull-down menu, a positive judgment is made in this judgment.

[0035] Next, the route search processing unit 22 performs a route search under the search condition "reflecting road tolls" and calculates a driving route to the destination (step 108).

[0036] Under the search condition of "road toll reflected", when searching for a driving route to a destination, a second cost corresponding to the toll road usage fee is added to a first cost as the passing time corresponding to each link, and the driving route with the lowest total cost to reach the destination is determined. For example, a value proportional to the usage fee (for example, a usage fee of 100 yen corresponds to a passing time of 1 minute) is used as the second cost. Note that the relationship between this second cost and the usage fee may be changed according to a user's instruction.

[0037] Incidentally, when comparing the costs of two search branches, there are cases where these two search branches include a common toll road with different entrances.

[0038] Figure 3 is an explanatory diagram of two search branches that include toll roads with different entrances. In the example shown in Figure 3, a search branch that enters the expressway from entrance A and a search branch that enters the expressway from entrance B overlap at link L1. In each search branch up to link L1, the exit of the expressway has not been determined, and therefore the toll fee for the expressway has not been determined either.

[0039] Therefore, in this embodiment, when two search branches to be compared in cost include a common expressway (toll road) with different entrances, a subsequent exit (most preferably the nearest exit) on this common expressway is identified, and the toll to this exit is calculated. In the example shown in Fig. 3, the toll from entrance A to exit C is calculated corresponding to one search branch, and the toll from entrance B to exit C is calculated corresponding to the other search branch, and a second cost proportional to these tolls is determined.

[0040] FIG. 4 is a diagram showing a specific example of cost comparison that reflects the toll fee. In this example, a usage fee of 100 yen is associated with a passing time of 1 minute. As shown in FIG. 4, if the search cost (corresponding to the first cost as the passing time) of the search branch from entrance A to exit C is 10 (minutes), the toll fee is 600 yen, and the toll cost (second cost) corresponding to the toll fee is 6 (minutes), the total cost is 16 (minutes). Also, if the search cost (first cost) of the search branch from entrance B to exit C is 12 (minutes), the toll fee is 300 yen, and the toll cost (second cost) corresponding to the toll fee is 3 (minutes), the total cost is 15 (minutes).

[0041] When the fee cost is not taken into consideration (conventional method), the cost (search cost) of these two search branches is less for the search branch via entrance A, so this search branch is selected. However, when the fee cost is taken into consideration, the cost (total cost) of these two search branches is less for the search branch via entrance B, so this search branch is selected.

[0042] If the user selects a search condition other than "road toll reflected", a negative determination is made in the judgment of step 106. Next, the route search processing unit 22 performs a route search using the selected search condition (step 110).

[0043] In this way, the navigation device of this embodiment can calculate the tolls of the multiple search branches to be selected by identifying the next exit of a common expressway with different entrances, and can compare the costs of these multiple search branches, making it possible to compare the costs of search branches taking the tolls into account even during route search. In particular, by identifying the first exit to be reached on a common expressway, it becomes easy to identify the section of the expressway for which the toll is to be calculated, and the processing load of the route search can be reduced. In addition, by setting the second cost corresponding to the toll to a value proportional to the toll, the cost according to the toll can be reflected in the route search, making it possible to determine whether it is worth using the expressway even if it means paying the toll.

[0044] The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the present invention. For example, in the above embodiment, a second cost having a value proportional to the toll (expressway toll) for the toll road is set, and the second cost is added to the first cost corresponding to the time to pass the road as the search branch to calculate the total cost, and the total costs are compared to select the search branch with the smallest cost. However, in addition to simply comparing the magnitude of the total costs, the following (1) or (2) may be added.

[0045] (1) A shortened time corresponding to the usage fee may be set (for example, a user may set on a setting screen how many minutes they would like to shorten the travel time for 100 yen within a specified range), and the route search processing unit 22 may select a search branch that includes a toll road, thereby selecting this option if the travel time can be shortened by more than the shortened time corresponding to the usage fee.

[0046] (2) An acceptable fee that can be paid to shorten a specified time may be set (for example, a user may set an acceptable amount to shorten the travel time by one minute on a settings screen), and the route search processing unit 22 may calculate the amount of time that can be saved by selecting a search branch that includes a toll road, and select this option if the toll for the toll road is cheaper than the acceptable fee corresponding to the shortened time.

[0047] These search methods enable route searches that associate the usage fee with the time saved. In addition, if the user sets the time saved, route searches can be performed that reflect the usage fee that each user is willing to accept for the time saved. [Industrial Applicability]

[0048] As described above, according to the present invention, it is possible to set the tolls for toll roads included in multiple search branches to be selected and compare the costs of these multiple search branches, making it possible to compare the costs of search branches taking into account toll road (expressway) tolls even in the middle of route search. [Explanation of symbols]

[0049] 1. Navigation Controller 3 Map data storage device 4 Control section 5. Vehicle position detection unit 6 Display device 7 Audio section 10 Map Buffer 12 Map reading control section 14 Map Drawing Section 20 Vehicle position calculation unit 22 Route search processing unit 24 Search condition setting section 28 Route guidance processing unit 30 Destination setting section 50 Input processing section 60 Display processing unit

Claims

1. A destination setting means for setting a destination; a map data storage means for storing map data including a first cost as a passing time for each of a plurality of links corresponding to a road; a route search means for searching for a driving route to the destination based on the map data stored in the map data storage means, by adding a second cost corresponding to a toll road fee to the first cost, and determining a driving route having the smallest total cost to reach the destination; the route search means repeats a process of selecting a search branch with the smallest cost from among a plurality of search branches to be compared in cost to the destination, and when a common toll road with different entrances is included in each of the plurality of search branches to be compared, sets the second cost using a toll to a subsequent exit on the common toll road; A navigation device, wherein the exit is a first arriving exit along a driving direction on the common toll road.

2. 2. The navigation device according to claim 1, wherein the second cost has a value proportional to a usage fee.

3. 3. The navigation device according to claim 1, wherein a shortened time corresponding to the toll fee is set, and the route search means selects a search branch including the toll road when the travel time can be shortened by more than the shortened time by selecting this option.

4. 4. The navigation device according to claim 3, wherein the shortened time period can be changed by a user.

5. 3. The navigation device according to claim 1, wherein an allowable fee that can be paid to shorten a predetermined time is set, and the route search means calculates the amount of travel time that can be shortened by selecting a search branch that includes a toll road, and selects this option if the toll for the toll road is cheaper than the allowable fee corresponding to the shortened time.

6. 6. The navigation device according to claim 5, wherein the allowable charge can be changed by a user.

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