JP3231508B2 - Route search display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel position display device for displaying the current position of a car or the like together with a map on a display device, and more particularly to a route search display device for searching for a route to a destination and displaying a search route on the display device. About.

[0002]

2. Description of the Related Art FIG. 2 shows an outline of a vehicle-mounted traveling position display device. In FIG. 2, 1 is an orientation sensor,
The direction sensor 1 uses a geomagnetic sensor for detecting the absolute running direction of the vehicle and an optical gyro for detecting the relative running direction of the vehicle. Reference numeral 2 denotes a distance sensor that generates a pulse corresponding to the number of rotations of the wheels, and 3 denotes various sensor signals such as an on / off signal of a brake switch, a parking switch, and the like, and a power supply voltage monitoring signal. Reference numeral 4 denotes a sensor signal processing unit for processing sensor signals such as a direction sensor 1 and a distance sensor 2. Reference numeral 5 denotes a GPS (Global Positioning System) receiver. The GPS receiver 5 receives radio waves transmitted from a plurality of satellites and performs calculations. By doing so, the position (latitude, longitude) of the receiving point can be obtained. Reference numeral 6 denotes a CD-ROM drive. The CD-ROM drive 6 reads map data from a CD-ROM 7 on which map data is recorded. Reference numeral 8 denotes a display / operation unit provided in the vehicle interior. The display / operation unit 8 is provided on a liquid crystal display 8A for displaying a map, a current traveling position, a direction, and the like of the automobile, and is provided on a front surface of the liquid crystal display 8A. The touch panel 8B includes switches for instructing enlargement and reduction of a display map,
A switch for instructing a route search, a switch for selecting a destination from the place names displayed on the liquid crystal display 8A, and the like are provided. Reference numeral 9 denotes an apparatus main body, which is installed in a trunk room or the like.

Next, the configuration of the apparatus main body 9 will be described.
10 is a CPU (Central Processing Unit) for performing various calculations, 11
Is a ROM (Read Only Memory) in which programs for various operations performed by the CPU 9 are stored, 12 is data from the azimuth sensor 1, the distance sensor 2, the GPS receiver 5, the CD-ROM drive 6, etc., and the operation results of the CPU 10, etc. (DRAM), 13 is a backup memory (SRAM) for holding necessary data even when power supply to the apparatus main body 9 is stopped, 14 is characters displayed on the liquid crystal display 8A, A memory (kanji, font ROM) in which patterns such as symbols are stored; 15 an image processor for forming a display image based on map data, current position data of the vehicle, etc .;
Map data, current location data and kanji output from
A memory (VRAM) for storing images to be displayed on the liquid crystal display 8A by synthesizing kanji and fonts such as street names and road names output from the font ROM 14;
This is an RGB conversion circuit for converting the output data of M16 into a color signal, and the color signal is output from the RGB conversion circuit 17 to the liquid crystal display 8A. Reference numeral 18 denotes a communication interface.

FIG. 3 shows a format of data stored in the CD-ROM 7, and reference numeral 20 denotes a disk label,
1 is a drawing parameter, 22 is map management information, and 23 is a map. The map stores background data, character data, road data, and the like.
Data for each unit map divided by longitude is stored. In the figure, a figure describing a wide area roughly and a figure describing a narrow area in detail are set. Each leaf is composed of map display levels A, B and C describing the same area. Map display levels A, B, and C are B,
C is described in more detail than B. Each of the map display levels A, B, and C is composed of map display level management information and a plurality of units. The unit describes a divided area obtained by dividing the area at each map display level into a plurality of areas. Each unit includes a unit header, a character layer, a background layer, a road layer, an option layer, and the like. The text layer contains the place names, road names,
The facility name and the like are recorded, the background layer records data for drawing roads, facilities, and the like, and the road layer stores coordinate points (nodes) describing roads including intersections as shown in FIG. And data related to lines (links), such as node numbers of nodes, latitude and longitude, link numbers of links, link distances, and the like. In FIG.
Circles (○) indicate nodes, and lines between nodes indicate links. A black circle (丸) of the node number: 4 indicates an intersection node. The data recorded in the road layer is not directly involved in the map display, but is used as road network information for map matching. In FIG. 3, reference numeral 24 denotes route search data. The route search data 24 includes search data recorded for each layer from layer 0 for a narrow area to layer n for a wide area. The search data of each layer is composed of node connection data 25, link estimated transit time (link cost) data 26, and route display data 27. The node connection data 25 includes, as shown in FIG.
This is data indicating which node y is connected to, for example, data indicating that node c is connected to nodes a, d, f, and y. The link cost data 26 indicates the link cost of the link between the nodes as shown in FIG. 5, for example, the link cost of the link between the node a and the node c is “5”, and the link cost of the node a The link cost of the link between the node a and the node b is “10”, and the link cost of the link between the node a and the node d is “20”. The link cost is obtained from link cost = link distance / set speed, and the set speed is set according to a road type and a road width as shown in FIG. 6, for example. The route display data 27 records data for displaying the route selected by the route search on the display map.

In FIG. 2, the output of the direction sensor 1 and the output of the distance sensor 2 are transmitted to the CPU 10
Sent to The CPU 10 calculates the current position of the vehicle, and obtains the latitude and longitude of the current position. Also GPS
The current position is corrected based on the data from the receiver 5. The map data of the unit corresponding to the current position is read from the CD-ROM 7 by the CD-ROM drive 6 based on the current position obtained in this manner, and the map data is stored in the memory (DRAM) 12 via the communication interface 18. Is stored. A part of the map data stored in the DRAM 12 is read by the CPU 10,
The image data is converted into image data by the image processor 15 and written into the image memory 16. The image data stored in the image memory 16 is converted into color signals by the RGB conversion circuit 17 and sent to the liquid crystal display 8A, where a map of a predetermined range centering on the current position is displayed. If the map data read from the DRAM 12 contains character codes and symbol codes, patterns corresponding to these character codes and symbol codes are read from the kanji and the font ROM 14, and characters such as place names are displayed on the liquid crystal display 8A together with the map. , School, etc. are displayed. Further, the current position displayed on the liquid crystal display 8A is sequentially changed based on the traveling speed and traveling azimuth sequentially obtained as the vehicle travels.

FIG. 1 shows a conventional route search operation.
This will be described with reference to FIG. As shown in FIG. 11, a destination is set in step A. The setting of this destination can be done by inputting the address of the destination, for example.
Alternatively, it is performed by designating a point on the map displayed on the display device 8. In step B, it is determined whether to start a route search. This determination is made based on whether or not the route search switch on the touch panel 8B of the display device 8 has been operated. If it is determined in step B that the route search switch has been operated, the process proceeds to step C, where a route search is performed. In this route search, as shown in FIG. 5, the link costs of all routes from the departure point (current position node) X to the destination node Y are added, and the route with the lowest link cost is selected. In the case of 5, link X → a → c → d
→ f → g → y total link cost (10 + 5 + 5 + 5 +
5 + 5 = 35) is the smallest, so the link X → a →
A route connecting c → d → f → g → y is selected. The route selected in step C of FIG. 11 is displayed in red on the display map of the display device 8 in step D, for example. FIG. 12 shows step C of the route search in FIG. 11 in further detail.
First, in step a, the departure node and the destination node closest to the departure and destination positions are selected. FIG. 5 shows that the node X is selected as the departure node and the node Y is selected as the destination node. Next, in step b, the route search data including the departure node X is stored in the CD-RO
After reading from M7, a route search on the departure point side is performed in step c. As described above, this route search selects the route with the lowest total link cost. Next, in step d, as a result of the search in step c, it is determined whether or not connection has been made to the target node. The distance from the departure point to the destination is relatively short.
If the destination node Y is included in the data read from the destination, the determination is yes in step d. However, if the destination is far from the departure point, the determination is no in step d and the determination is no in step e. move on. At step e, route search data including the destination node Y is read from the CD-ROM 7, and at step f, a route search on the destination side is performed. In step g, it is determined whether or not the route selected by the route search on the destination side in step f is connected to the search route on the departure side. If the result of this determination is no, FIG.
In step h in, the search hierarchy is raised by one rank. If the read data in step b and step e is the route search data of layer 0, the rank is raised to layer 1 in step h. Next, in step i, the starting node and the destination node are reset, and the process returns to step b.

FIG. 7 shows that the distance between the departure point and the destination is long,
FIG. 13 is a diagram for easily understanding the operation in the case where it is determined to be No in step d and step g in FIG. 12, wherein the route selected in the route search on the departure side is not connected to the destination node, and the route on the destination side is If the route selected in the search is not connected to the route searched in the departure route search, the route search data 28 of the hierarchy 1 is read and the departure node 2
9. The destination node 30 is set. When the route indicated by the solid line is searched by the route search in the hierarchy 1, the determination is yes in step d of FIG. 12, and the process proceeds to step j. In step j, the route from the departure point to the destination is formed. The display data of the selected route is created, and the route search ends.

FIG. 13 shows a display example on a display device. In FIG. 13, reference numeral 31 denotes a departure place (current position);
Indicates a destination, and a broken line indicates a route selected by the route search.

[0009]

However, in the route search in the above-mentioned conventional example, since the route is selected according to a predetermined ring cost for each node, the vehicle travels along the selected route. There is a problem in that even if the user encounters a traffic jam on the way, only the route selected by the route search is displayed.

A first object of the present invention is to automatically search a route again and select a detour with no traffic congestion when a traffic congestion or the like is encountered while traveling along the searched route. a <br/> to provide a route search display device capable of displaying.

A second object of the present invention is to easily find a corrected link cost by multiplying a link cost determined in advance by a link distance and a set speed for each link by a correction coefficient to the set speed. it is to provide a route search display device capable.

Further, a third object of the present invention is to obtain a modified link cost according to a distance to a destination, so that a search route tends to change as the position is closer to the current position in a next route search. a <br/> to provide a route search display accurate route guidance is possible in accordance with the road situation.

A fourth object of the present invention is to provide a route search display device capable of automatically correcting a link cost and re-searching a route when the average speed of the vehicle drops below a predetermined value. That is.

[0014]

Means for Solving the Problems A first invention of the present invention is:
In order to achieve the above object, a storage means in which road data is recorded as a set of links connecting a node to a road network, and each of the links is used by using the road data recorded in the storage means. A route search means for searching for a route from the departure point to the destination with reference to the assumed link passage time preset in advance, and the route search means
Display means for displaying the shortest time route together with the map; speed measuring means for measuring the average speed of the own vehicle traveling on the shortest time route searched by the route searching means; and the speed of the own vehicle measured by the speed measuring means. link assumed transit time correction means average speed to modify the link assumed transit time of the searched shortest time route by the route searching means when it is small site-size constant than the predetermined value, the said link assumed transit time correction means The search is performed again by the route search means using the corrected estimated link passage time and the estimated link passage time of another link.

According to a second aspect of the present invention, when the determination means determines that the average speed of the vehicle is smaller than a predetermined value,
The modified link cost is obtained by multiplying the set speed by a correction coefficient.

A third invention of the present invention is characterized in that the correction coefficient is larger for a link closer to the destination.

According to a fourth aspect of the present invention, when the determination means determines that the average speed of the vehicle is smaller than a predetermined value,
It is characterized in that the assumed link time is automatically corrected by the assumed link time correction means and the re-search is performed by the route search means.

[0018]

According to the first aspect of the present invention, if the average speed falls below a certain value due to traffic congestion or the like while the vehicle is traveling along the search route, the link cost is corrected. The route search is performed again, and a route that can avoid the influence of traffic congestion or the like is automatically searched and displayed.

According to the second aspect of the present invention, the corrected link cost can be easily obtained only by multiplying the set speed set for the link of the search route by the correction coefficient.

According to the third aspect of the present invention, since the correction coefficient differs depending on the distance to the destination, a route that reaches the destination in the shortest time while avoiding the influence of traffic congestion is searched and displayed. You can do it.

According to the fourth aspect of the present invention, when the average speed becomes equal to or less than the predetermined value, the link estimated passage time is automatically corrected without manual operation, and the corrected link passing time is corrected. The route search is automatically performed again using the assumed link passage time and the assumed link passage times of other links.

[0022]

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, as shown in FIG. 8, a destination is set in step a, it is determined whether or not to perform a route search in step b. If it is determined that a route search is to be performed, a route is determined in step c. Perform a search. The result of this route search is the same as that of the conventional example, and the route searched in the next step d is displayed on the display device 8 (this route display is the same as the conventional example shown in FIG. 13). Next, the process proceeds to step e. Step e is a step of calculating the average speed of the own vehicle after traveling on the search route for a predetermined time, and the average speed measured in step e is constant at step f (for example, 20K / h).
m) is determined. If the determination is no in step f, the process returns to step d. On the other hand, if the determination is yes in step f, the link cost of each link of the previously searched route is corrected in step g.

FIG. 9 shows a link cost correction coefficient, which differs according to the distance to the destination.
The corrected link cost using this correction coefficient is calculated by the following formula: corrected link cost = (link distance) / (set speed × correction coefficient). If the average speed obtained after traveling on the route selected in the previous route search for a predetermined time is smaller than a predetermined value, the link cost of each link of the route selected in the previous route search is corrected. The coefficient is set as shown in FIG. 9 according to the distance to the destination. That is, since the correction coefficient of the link near the current position is small, the corrected link cost of the link near the current position has a large value,
On the other hand, the correction coefficient of the link distant from the current position becomes a value close to 1, and the corrected link cost calculated by the above equation decreases. As described above, the link cost of each link of the route selected in the previous route search is corrected in step g, and the second route search is performed in step h. As described above, among the links of the previous search route, the correction that the correction link cost increases as the link is closer to the current position is performed. Therefore, in the second route search, among the links selected in the previous route search, , The link closer to the current position is less likely to be selected. In step i, it is determined whether or not the destination has been reached. If the determination is no, the process returns to step d,
The route selected in the second route search is displayed on the display device 8. FIG. 10 shows a display screen displaying the route searched in the second route search.

As described above, according to the above-described embodiment, when the average speed is reduced due to traffic conditions such as traffic congestion on the route searched by the route search, the link cost is automatically corrected. Then, the route search is performed again using the corrected link cost, so that a detour at a location close to the current position where traffic congestion or the like has occurred can be displayed as a re-search route.

[0025]

According to the first aspect of the present invention, an optimum route search can be performed according to road conditions such as traffic congestion. Further, according to the second aspect, the corrected link cost can be easily calculated by multiplying the set speed for obtaining the link cost of each link by the correction coefficient. Further, according to the third invention of the present invention, there is an advantage that a route that can reach the destination in the shortest time can be sequentially searched and displayed while avoiding a current traffic jam or the like. According to the fourth aspect of the present invention, when the average speed falls below a predetermined value, the route is automatically searched again without any manual operation, and the route is displayed on the display device. You can do it.

[Brief description of the drawings]

FIG. 1 is a block diagram of a route search and display device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a traveling position display device according to the embodiment;

FIG. 3 is a view showing a format of a CD-ROM of the embodiment.

FIG. 4 is a view showing road data recorded on a CD-ROM of the embodiment.

FIG. 5 is an exemplary view for explaining a route search method according to the embodiment;

FIG. 6 is a diagram showing a set speed for calculating a link cost in the embodiment.

FIG. 7 is a view for explaining a hierarchical structure for a route search in the embodiment.

FIG. 8 is a flowchart of a route search in the embodiment.

FIG. 9 is a view showing a link cost correction coefficient of the embodiment.

FIG. 10 is a diagram showing a route selected by the re-search according to the embodiment.

FIG. 11 is a flowchart of a route search performed by a conventional route search display device.

FIG. 12 is a flowchart of a route search performed by a conventional route search display device.

FIG. 13 is a diagram showing a route selected by a conventional route search.

[Explanation of symbols]

 Reference Signs List 1 direction sensor 2 distance sensor 5 GPS receiver 6 CD-ROM drive 7 CD-ROM 8 display / operation unit 8A liquid crystal display 8B touch panel 9 device body 10 CPU 15 image processor 24 route search data 25 node connection data 26 link cost data 27 route Display data

Claims (5)

(57) [Claims] 1. A route from a departure point to a destination is searched for by referring to a link assumed transit time set in advance for each of the above-mentioned links, using road data that is a set of links connecting the road network to the nodes. Route searching means, guiding means for guiding the route, and speed measuring means for measuring the average speed of the self traveling on the route, when it is determined that the average speed of the self is less than a predetermined value The link assumed transit time of the link on the route is corrected so that the link near the destination has a smaller rate of increase in the link assumed transit time than the link that is farther, and the corrected link assumed transit time of the link on the route is corrected. by referring to the time, route searching device characterized by performing the search on SL route search unit again. 2. A route from a departure point to a destination is searched by using road data, which is a set of links connecting nodes between nodes in a road network, with reference to an assumed link time set for each of the links. Route searching means, guiding means for guiding the route, and speed measuring means for measuring the average speed of the self traveling on the route, when it is determined that the average speed of the self is less than a predetermined value The link estimated transit time of the link on the route is corrected so that the link near the current location has a larger increase rate of the estimated link transit time than the link farther from the link. by reference, the route searching apparatus and performs search on SL route search unit again. 3. An estimated link passage time based on a link speed and a set speed preset according to a road type and a road width, and if the average speed of the vehicle is smaller than a predetermined value. when it is judged, according to claim 1, characterized in that to fix the links assumed transit time of the link on the route based on link distance / (set speed × correction coefficient)
Or the route search device according to claim 2. 4. By determining the correction coefficient according to the distance from the current position to the link, the route search device 請 Motomeko 3 wherein you characterized by modifying the link assumed transit time. 5. A road network is a set of links connecting nodes, and a route from a departure point to a destination is searched for with reference to an assumed link passage time set in advance for each link, and the above route is traveled. When the average speed of the link is determined to be smaller than the predetermined value, the link near the current location is corrected to have a larger rate of increase in the estimated link transit time than the link that is farther, and the link of the link on the corrected route is corrected. by referring to the envisaged passage time, the route search method characterized by performing again the search.