JP3376748B2 - Route guidance method for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle route guidance method.

[0002]

2. Description of the Related Art In recent years, the technology of a car navigation system (vehicle route guidance system) has advanced, and a display device installed in the driver's seat displays a route map along with a route previously registered from a starting point to a destination and a GPS. Not only is it used to calculate and display the current position of the vehicle, but the shortest route from the current position of the vehicle to the destination is automatically calculated on the road map, and the result is displayed on the road map of the display device. The one with the function of displaying easily has also been put to practical use.

In addition, the traffic information mainly including the traffic congestion information is received and analyzed, and a special display showing the traffic congestion is displayed on the road map of the display device, for example, the target road is displayed with a thick red line. Add red or other colored lines beside the target road,
The shortest time can be given by adding a function such as adding an arrow to inform the occupants, or by receiving and analyzing external traffic information and adding the average hourly speed of the congested road when determining the shortest route to the destination. There is also proposed a device that has a function of automatically calculating and displaying a route that can reach the destination.

[0004]

However, in the conventional route guidance device for a vehicle, when all the congested roads are conspicuously displayed on the road map displayed on the display device based on the received traffic information, Although the passenger actually needs only the road condition on the target local side, there is a problem that it becomes difficult to see because the display condition is mixed with many unnecessary road conditions.

Further, in the method of displaying the shortest time route to the destination in consideration of the traffic information, recalculation is required every time the content of the traffic information changes, and the load on the microcomputer mounted on the device is increased. There is a problem that it is large and it takes time to recalculate. In addition, since one route is determined and displayed on the device side, the occupant can select the route in the middle while empirically knowing how to reach the destination. There was also a problem that was not very helpful when taking the driving method to go.

The present invention has been made in view of the above conventional problems, and presents a plurality of recommended routes that take a relatively short time in consideration of traffic information, and allows an occupant to perform flexible route selection. It is an object of the present invention to provide a vehicle route guidance method capable of performing the following.

[0007]

According to another aspect of the present invention, there is provided a route guidance method for a vehicle, which detects a current position of a vehicle, displays a road map of a region including the current position of the vehicle on a display device, and externally displays the map. Receives and analyzes the traffic information of the roads to identify the congested roads on the road map, and excludes the roads identified as the congested roads from each road from any intersection on the road map to other intersections adjacent to it. Then, on the road map of the display device, each shortest distance route connecting the current position of the vehicle to each road end point on the display screen is calculated, and the calculated shortest distance route is compared with other roads on the road map of the display device. It is displayed in a distinguishable form.

According to a second aspect of the invention, in the vehicle route guiding method according to the first aspect of the invention, a display showing the direction of the destination is added on the road map displayed by the display device.

A vehicle route guidance method according to a third aspect of the present invention is
Detects the current position of the own vehicle, displays a road map of the area including the current position of the own vehicle on the display device, receives external traffic information, from any intersection on the road map to other intersections adjacent to it The time required for each road is calculated, the shortest time route that connects from the current position of the vehicle to each road end point on the display screen is calculated on the road map of the display device, and the calculated shortest time route is set in advance. By comparing with the required time threshold value, only the routes that do not exceed the threshold value are selected and displayed on the road map of the display device in a form in which they can be distinguished from other roads.

A vehicle route guidance method according to a fourth aspect of the present invention is
Detects the current position of the own vehicle, displays a road map of the area including the current position of the own vehicle on the display device, receives external traffic information, from any intersection on the road map to other intersections adjacent to it The time required for each road is calculated, the shortest time route connecting from the current position of the vehicle to each road end point on the display screen is calculated on the road map of the display device, and the predicted average is calculated for each calculated time shortest route. Find the speed, compare it to the preset speed threshold,
Only the route exceeding the threshold value is selected and displayed on the road map of the display device so as to be distinguishable from other roads.

According to a fifth aspect of the invention, in the vehicle route guiding method according to the third or fourth aspect of the invention, a display indicating the direction of the destination is added on the road map displayed by the display device.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a system configuration of a vehicle route guiding device that realizes the vehicle route guiding method of the present invention will be described. Figure 1
Indicates a vehicle route guidance device, which is installed near the driver's seat, and an input operation unit 1 including button switches, number keys, cursor keys, etc. for starting and stopping the device and performing various input operations. A display 2 such as a CRT or LCD, a display controller 3 for controlling the display of the display 2, an external storage such as a CD-ROM driving device for driving a CD-ROM in which road map information of various areas is stored. Device 4, GPS 5 for determining the current position of the vehicle,
A gyro 6 for detecting the traveling direction, a vehicle speed sensor 7 for detecting the vehicle speed, which is provided for correcting the current position of the vehicle calculated by the GPS 5, a traffic information receiving device 8 for receiving a broadcast signal of traffic congestion information, Centrally control each device,
CPU 9 for performing arithmetic processing such as map information, traffic information analysis, shortest route calculation, ROM 10 in which programs executed by this CPU 9 and other fixed data are registered, CPU
RA storing variable data used for 9 operations
It is composed of an M11 and a bus 12 connecting between the respective devices.

Various types of traffic information receivers 8 are used according to the type of traffic congestion information provided, and receivers corresponding to FM broadcast waves, optical / radio wave beacons, etc. are used.

Next, a first embodiment of a vehicle route guiding method using such a vehicle route guiding device will be described. By giving a display command from the input operation unit 1,
The CPU 9 gives an instruction to the GPS 5, and causes the GPS 5 to detect a current position of the vehicle by receiving a signal from a space satellite by a conventionally known method. Then, the CPU 9 reads out road map information of an area including the vehicle position from the map information registered in the external storage device 4, and causes the display control unit 3 to display this road map on the display device 2 at a designated scale. To do so. FIG. 2 shows a road map displayed on the display device 2 (in the display example of FIG. 2, for convenience of explanation, one section of the road map is just displayed, which will be described later. Congested roads based on traffic congestion information are shown with arrows).

In the road map shown in FIG. 2, FIG. 3 and FIG.
As shown in, each intersection existing on the map is defined as a node A, B, C, ..., I, and if a road is connected between an arbitrary intersection and an adjacent intersection, the roads are linked. Further, the nodes at both ends of each link and the length of the link (that is, distance data between intersections, which is used as cost data in the Dijkstra method described later) are registered in a data table format. Further, for each road that extends beyond the edge of the display screen of the road map displayed on the display device 2, each endpoint is registered as a leaf node J, K, L, ..., S like an intersection. ing. In FIG. 3, a road having only one-direction arrow indicates a one-way road. In the data table of FIG. 5, for example, D (A, B) indicates the distance data together with the link of the intersection A → B, and D (B, A) indicates the intersection B → A.
The distance data is shown together with the link. And D
If (A, B) exists and D (B, A) does not exist, it is regarded as a one-way road from the intersection A to B.

The CPU 9 also gives an instruction to the traffic information receiving device 8 to receive the traffic congestion information, analyzes the traffic congestion information obtained from the traffic congestion information, and analyzes the traffic congestion information along the roads shown in FIG. As shown in the data table of FIG. 6, B
→ A, I → A, A → I, E → A, R → B, S → H, J →
Roads such as H, H → G, ... Are specified as congested roads whose average traveling speed is a predetermined speed or less (for example, 15 km / h or less). Then, the congested road data is compared with the data tables shown in FIGS. 3 and 5, and the congested roads (links marked with a broken line X in FIG. 5) are deleted from the data table, so that the roads having a relatively smooth flow. Extract only the data table for. FIG. 4 shows a data table after deleting a congested road, for example, nodes A and B.
Regarding the road between them, the road in the direction of B → A is deleted from the data table because it is congested, and only the link in the direction of A → B is left between the nodes A and B. Similarly, as for the road between nodes A and E, the road in the direction of E → A is deleted because it is congested, and only the link in the direction of A → E remains.

The above processing is executed for all the links on the road map displayed on the display device 2, and the result is as shown in FIG. Here, there is no particular limitation on how many km / h or less the average traveling speed is used to determine the traffic jam road, and the operator may set it by the input operation unit 1. You can also set it. Further, since the speed at which traffic congestion is felt differs between the urban area and the suburbs, it is possible to register the traffic congestion speed determination value in the map information in advance.

Next, the CPU 9 starts from the present position ST of the own vehicle and ends (leaf nodes) J, K, L, ..., On the display screen.
The calculation process of the shortest path to S will be started. The calculation processing of this shortest path is based on, for example, the Dijkstra method shown in the flowchart of FIG. Explaining this Dijkstra method, as an initial setting, all nodes (intersections and road end points) in the data table shown in FIG. 4 except for the links marked with a broken line X in FIG.
The cost of A, B, C, ... Is set to ∞, the end point of the link at the position where the vehicle currently exists, here point E is set as the starting intersection, and the cost is set to 0 The intersection is set (steps 100 and 102).

Next, in the data table obtained in FIG. 4, one of the intersections adjacent to the central intersection E, for example point D, is selected, and the cost of the central intersection E is 0, with the distance between E and D as the cost. And the distance cost between the central intersection and the selected adjacent intersection is added to g (steps 104, 10).
6).

Then, the cost of this adjacent intersection is compared with the above-mentioned g value, and if the g value is smaller, this g value is newly set as the cost of the adjacent intersection D, and the central intersection E is determined. It is the immediately preceding intersection with respect to the adjacent intersection D under consideration. Then, this adjacent intersection is added to the candidate list of one passing intersection for the shortest route (step 10).
8, 110, 112). However, step 106
If the g-value obtained in step (4) is larger than the cost of the adjacent intersection currently being considered, the cost of the adjacent intersection is left unchanged (branching to the N0 side in step 108).

The above steps 104 to 112 are executed for all the adjacent intersections in the data table obtained in FIG. 4 with respect to the current central intersection, here E point (in the present example, the rest are only F points). (Yes) is executed (step 114).

As a result of executing the above processing for each of the D point and the F point adjacent to the point E as the central intersection, the cost of the adjacent intersection is ∞ because both the D point and the F point remain the initial settings. The g value becomes smaller, and both D point and F point are added to the candidate list.

Next, among the intersections added to the candidate list in step 112, the intersection with the minimum cost is extracted as a new central intersection, and the process returns to step 104 and all the new central intersections are extracted. The steps 104 to 114 are repeated for the adjacent intersections (steps 116 to 120). Then, when the processing of steps 104 to 114 is completed for one central intersection, for other adjacent intersections added to the candidate list,
The same process is repeated (YES in step 120).

When the candidate list becomes empty in step 120, for each node (leaf node) at the road end point on the road map display screen of the display device 2, the preceding intersection is sequentially reached from the leaf node to the departure intersection E. In reverse, the distance shortest route is determined for each leaf node (step 122).

The shortest route thus obtained is displayed on the road map of the display device 2 and presented to the occupant as shown in FIG. In the shortest route display example shown in FIG. 7, the route to the leaf nodes M and A is not determined, but this is the step of link selection based on the traffic congestion information described above.
This is because the links of M and the links of B → A and I → A have been deleted, so that there is no route from the starting point E to each of these leaf nodes M and P.

In this way, according to the vehicle route guidance method of the first embodiment, on the road map displayed on the display device 2, the traffic congestion information is taken into consideration and the current position of the vehicle is changed. The shortest route to reach the end point of each road extending outside the display screen can be automatically derived and presented to the occupant, and the occupant can refer to the display to get to the destination on the congested road. By avoiding the above, it is possible to select a desired route from a plurality of routes that take relatively little time, taking into account one's preference and experience, and it is possible to increase the degree of freedom in route selection.

Incidentally, in the above-mentioned first embodiment, FIG.
By inputting the destination data from the input operation unit 1 together with the display of the shortest route shown in FIG.
It is possible to additionally display a part such as an arrow a indicating the direction in which the destination exists on the road map displayed on the. By displaying the destination direction indicating arrow a, Conventionally, the shortest route is, for example, E → F.
-> Only the route of L was displayed, but this E->F->
Along with L route, E → F → G → K, and further E → D → C
Routes such as → H → J are also candidates for selection, avoiding congested roads to reach your destination, and choosing your preferred route from multiple routes that take a relatively short time, taking into account your own preferences and experience. This makes it possible to increase the degree of freedom in route selection.

Further, in the above-mentioned first embodiment, the display example in which one section is one screen of the road map has been described, but the display of the road map by the display device 2 is a continuous scroll system and is shown in FIG. A plurality of partitions 16a, 16b, 16c, 16 in which the display area 15 of the display device 2 is adjacent
In the case of spanning d, the CPU 9 calculates the leaf nodes to be calculated up to, for example, FIG.
The outermost intersections A1 to A7 within the range included in the display area 15 are set as leaf nodes as shown in 0, or the outer edges adjacent to the outermost intersections included in the display area 15 as shown in FIG. It is possible to adopt a method in which each of the intersections B1 to B10 is used as a leaf node to calculate the shortest route and only the display area 15 is displayed. Further, as shown in FIG. 12, the shortest route is calculated by using each of the outer boundary points C1 to C7 of the plurality of sections 16a, 16b, 16c, 16d related to the display area 15 as a leaf node, and only the inside of the display area 15 is calculated. It can be displayed.

Next, a vehicle route guiding method according to a second embodiment of the present invention will be described. The vehicle route guiding method of the second embodiment is also executed by using the vehicle route guiding apparatus shown in FIG. 1, but the program executed by the CPU 9 is changed.

First, by giving a display command from the input operation unit 1, the CPU 9 gives an instruction to the GPS 5 and GP.
In S5, a signal is received from the space satellite by a conventionally known method to detect the current position of the vehicle. Then, the CPU 9 reads out road map information of an area including the vehicle position from the map information registered in the external storage device 4, and causes the display control unit 3 to display this road map on the display device 2 at a designated scale. To do so. FIG. 13 shows a road map displayed on the display device 2.

Next, the CPU 9 creates a required time data table for each road as shown in FIG. 14 from the wide area traffic information received by the traffic information receiving device 8 and stores it in the RAM 11. In this required time data table, for example, T
Even if (A, B) exists, if T (B, A) is not registered, it is determined that the road between A and B is a one-way road of A → B (see FIG. 3).

When the CPU 9 creates the required time data table between the intersections as shown in FIG.
Next, based on the flowchart of FIG. 8, from the starting point E to the end point (leaf node) of the display screen by the Dijkstra method.
The shortest time route to each of J, K, L, ..., S is determined. In this process, in the flowchart of FIG. 8, the distance data shown in FIG. 5 is used as the cost in the first embodiment, but the required time data shown in FIG. 14 is used as the cost in the second embodiment. The only difference is that the other processing is the same as in the first embodiment.

The shortest path from the starting point E thus obtained to each leaf node is as shown in FIG. 15 (a). In the second embodiment, the following selection is further executed. . That is, a selection is made to exclude a leaf node that requires a preset threshold time (from the starting point to a certain leaf node) that takes more than a preset threshold value (it depends on the map scale, for example, 1 hour), or the index is calculated. (B) the average speed (= total travel distance / estimated total required time) of the shortest time route for each leaf node is excluded from a certain threshold value (for example, 20 km / h). As shown in (), a relatively thin road is displayed on the road map of the display device 2 and presented to the occupant.

Thus, according to the vehicle route guiding method of the second embodiment, the traffic map information is added to the current position of the vehicle on the road map displayed on the display device 2. The shortest time to reach the end point of each road extending outside the display screen can be automatically derived and presented to the occupant, and the occupant can refer to the display and be congested to reach the destination. By avoiding the road, it becomes possible to select a desired route from a plurality of routes that take a relatively short time, taking into account one's preference and experience, and the degree of freedom in route selection can be increased.

In the second embodiment as well, the CPU 9 displays on the display device 2 by inputting the destination data from the input operation unit 1 together with the display of the shortest route shown in FIG. 15 (b). It is possible to additionally display a part such as an arrow a indicating the direction in which the destination exists on the road map being displayed, and by displaying the destination direction indicating arrow a, conventionally, As the shortest route, for example, only the route of E → F → L was displayed, but along with this route of E → F → L, the route of E → D → C → H → J is also a selection candidate, and it is necessary to go to the destination. By avoiding the congested road, it is possible to select a desired route from a plurality of routes that take relatively little time, taking into account one's own preference and experience, and the degree of freedom in route selection can be increased.

Also, in the second embodiment described above, the display example in which one section is one screen of the road map has been described, but the display of the road map by the display device 2 is a continuous scroll system, and is shown in FIG. A plurality of partitions 16a, 16b, 16c, 16 in which the display area 15 of the display device 2 is adjacent
In the case of straddling d, as in the variation of the first embodiment, as to how far the CPU 9 calculates the leaf node to be calculated, for example, within the range included in the display area 15 as shown in FIG. Outermost intersection A1
Each of A7 is set as a leaf node, or as shown in FIG. 11, the outermost intersections B1 to B10 adjacent to the outermost intersection included in the display area 15 are set as leaf nodes to calculate the shortest route, and the display area 15 is displayed. You can take the method of displaying only. In addition, as shown in FIG. 12, a plurality of partitions 16a, 16 related to the display area 15 are provided.
It is also possible to calculate the shortest route using all the outer boundary points C1 to C7 of b, 16c, and 16d as leaf nodes and display only the display area 15.

[0037]

As described above, according to the invention of claim 1,
Detects the current position of the own vehicle, displays a road map of the area including the current position of the own vehicle on the display device, receives external traffic information and analyzes it to determine the congested road on the road map, and displays it on the road map. Among the roads from any intersection to other intersections adjacent to it, exclude the roads that have been identified as congested roads, and display the current position of the vehicle on the road map of the display device from each road end point on the display screen. The shortest distance route that connects to each is calculated, and the calculated shortest distance route is displayed on the road map of the display device in a form that can be distinguished from other roads, so it can be changed even if the route to the destination is changed on the way. It is possible to reduce the frequency of recalculating the shortest route corresponding to the position of the own vehicle as much as possible, reduce the chance of waiting for a long time for recalculation, and from the multiple routes displayed on the display device. Crew experience Taking into account the preferences able to travel by selecting an optimal route, the degree of freedom in routing increases.

According to the invention of claim 2, since the display showing the direction of the destination is added to the road map displayed by the display device together with the plurality of routes determined by the invention of claim 1, You can easily recognize the relationship between the direction of the destination and the route outside the screen, and you can select one route from the multiple routes leading to the destination, and you can freely select the route to the destination. You can increase the degree.

According to the third aspect of the present invention, the current position of the own vehicle is detected, a road map of the area including the current position of the own vehicle is displayed on the display device, external traffic information is received, and the road map is displayed. Calculate the required time for each road from any given intersection to other intersections adjacent to it, and calculate each shortest time route that connects the current position of the vehicle to each road end point on the display screen on the road map of the display device. , Comparing each of the calculated shortest time routes with the preset required time threshold, and selecting only the routes that do not exceed the threshold,
Since it is displayed on the road map of the display device in a form that can be distinguished from other roads, even if the route to the destination is changed on the way, the frequency of recalculating the shortest route corresponding to the changed vehicle position as much as possible You can reduce the number of times, you can reduce the opportunity to wait for a long time for recalculation, and select the most suitable route from the multiple routes displayed on the display device taking into account the experience and tastes of the occupant. It is possible to increase the freedom of route selection.

According to the invention of claim 4, the current position of the own vehicle is detected, the road map of the area including the current position of the own vehicle is displayed on the display device, and external traffic information is received to display on the road map. Calculate the required time for each road from any given intersection to other intersections adjacent to it, and calculate each shortest time route that connects the current position of the vehicle to each road end point on the display screen on the road map of the display device. , Calculate the predicted average speed for each of the calculated shortest time routes, compare it with a preset speed threshold, select only the routes that exceed the threshold, and select other roads on the road map of the display device. Since it is displayed in a form that can be identified as, even if the route to the destination is changed on the way, it is possible to minimize the frequency of recalculating the shortest route corresponding to the changed vehicle position,
It is possible to reduce the opportunity to wait for a long time for recalculation, and it is possible to select the optimal route from the multiple routes displayed on the display device taking into account the experience and tastes of the occupants and drive. More freedom of choice.

According to the invention of claim 5, a display showing the direction of the destination is added to the road map displayed by the display device together with the plurality of routes determined in the invention of claim 3 or 4. , It is possible to make the occupant easily recognize the relationship between the destination direction and the route outside the screen, and select one route from the multiple routes that lead to the destination, and select the route to the destination. The degree of freedom of can be increased.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a vehicle route guidance device used in a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a road map read from an external storage device and displayed on a display device in the first embodiment.

FIG. 3 is an explanatory diagram showing a link relationship between intersections.

FIG. 4 is an explanatory diagram showing a link relationship excluding traffic congestion links among the link relationships between intersections.

FIG. 5 is an explanatory diagram showing an example of a distance data table between intersections.

FIG. 6 is an explanatory diagram showing an example of a data table of a road in which traffic congestion occurs.

FIG. 7 is an explanatory diagram showing a state in which the shortest distance route obtained by the method of the first embodiment is displayed on the display device.

FIG. 8 is a flowchart showing the Dijkstra method used in the above embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a display area extending over a plurality of unit sections of a road map and each unit section.

FIG. 10 is an explanatory diagram showing an example of the shortest route calculation when the display area extends over a plurality of unit partitions.

FIG. 11 is an explanatory diagram showing another example of the shortest route calculation when the display area extends over a plurality of unit partitions.

FIG. 12 is an explanatory diagram showing still another example of the shortest route calculation when the display area extends over a plurality of unit partitions.

FIG. 13 is an explanatory diagram showing an example of a road map read from an external storage device and displayed on a display device according to the second embodiment of the present invention.

FIG. 14 is an explanatory diagram showing an example of a required time data table created based on traffic congestion information received by the traffic information receiving device in the second embodiment.

FIG. 15 is an explanatory diagram showing a method of excluding a route having a slow average speed in the second embodiment.

[Explanation of symbols]

1 Input operation section 2 display 3 Display control unit 4 External storage device 5 GPS 6 gyro 7 vehicle speed sensor 8 Traffic information receiver 9 CPU 10 ROM 11 RAM 12 buses

Claims (5)

(57) [Claims] 1. A congestion road on the road map, which detects the current position of the own vehicle, displays a road map of the area including the current position of the own vehicle on a display device, receives and analyzes external traffic information. Of the roads from any intersection on the road map to other intersections adjacent to it, excludes the roads indexed as the congested roads, and displays the current vehicle on the road map of the display device. A vehicle characterized in that each shortest distance route connecting the position to each road end point on the display screen is calculated, and the calculated shortest distance route is displayed on the road map of the display device so as to be distinguishable from other roads. Route guidance method. 2. The route guiding method for a vehicle according to claim 1, wherein a display indicating the direction of the destination is performed on the road map displayed by the display device. 3. A current position of the own vehicle is detected, a road map of an area including the current position of the own vehicle is displayed on the display device, external traffic information is received, and an arbitrary intersection is displayed on the road map. The required time for each road to another adjacent intersection is calculated, and the shortest time route that connects the current position of the vehicle to each road end point on the display screen is calculated on the road map of the display device, and the time is calculated. Comparing each of the shortest time routes with a preset required time threshold, selecting only routes that do not exceed the threshold, and displaying them on the road map of the display device in a form that can be distinguished from other roads. A route guidance method for a vehicle. 4. A current position of the own vehicle is detected, a road map of an area including the current position of the own vehicle is displayed on a display device, external traffic information is received, and an arbitrary intersection is displayed on the road map. The required time for each road to another adjacent intersection is calculated, and the shortest time route that connects the current position of the vehicle to each road end point on the display screen is calculated on the road map of the display device, and the time is calculated. A mode in which a predicted average speed is obtained for each of the shortest time routes, the speed is compared with a preset speed threshold value, and only the route exceeding the threshold value is selected so that other roads can be identified on the road map of the display device. A route guidance method for vehicles, characterized by being displayed. 5. The vehicle route guidance method according to claim 3, wherein a display indicating the direction of the destination is performed on the road map displayed by the display device.