JPH09329451A - Route search and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To indicate the optimum route corresponding to the traffic condition to a driver, by searching the optimum route corresponding to the real passing speed on the basis of the result of learning on the route to the input destination, and displaying the same. SOLUTION: The link conversion process by CPU is performed by judging whether a vehicle is matched on a network of a road layer, or not (S1), and determining an average speed for passing the link (S2). Then a link cost of the link during the travelling, is selected from a search data (S3). Then the real link cost is determined by dividing the link distance of the current travelling (S4), by the average speed at the real passing. Further the new link cost is determined by learning the link cost by a calculation formula, the link cost is memorized, and the link cost which has been univocally regulated by the kind of road and the road width, is rewritten, to form the link cost optimum for the real travelling condition (S5) and to search a route. An optimum route can be found by this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling position display device for displaying the current position of a car or the like on a display device together with a map.
In particular, the present invention relates to a route search and display device that searches for a route to a destination and displays the searched route on a display device.

[0002]

2. Description of the Related Art An outline of a conventional vehicle-mounted traveling position display device will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes an azimuth sensor, which uses a geomagnetic sensor for detecting the absolute traveling azimuth of an automobile and an optical gyroscope for detecting the relative traveling azimuth of the automobile. Two
Is a distance sensor that generates a pulse according to the rotation speed of the wheel,
Reference numeral 3 denotes various sensor signals such as an ON / OFF signal of a brake switch and a parking switch, and a power supply voltage monitoring signal. 4 is GPS (Global Position)
ing System) receiver, and it is possible to obtain the position (latitude, longitude) of the receiving point by receiving and calculating radio waves transmitted from a plurality of satellites. 5 is C
It is a D-ROM drive and C that stores map data.
The map data is read from the D-ROM 6. Reference numeral 7 denotes a display / operation unit installed in the passenger compartment, which includes a liquid crystal display 7A for displaying a map and the current traveling position and direction of the automobile, and a touch panel 7B provided on the front surface of the liquid crystal display 7A. Is equipped with a switch for instructing enlargement / reduction of the displayed map, a switch for instructing a route search, a switch for selecting a destination from the place names displayed on the liquid crystal display 7A, and the like. Reference numeral 8 is a main body of the apparatus.

The structure of the apparatus main body 8 will be described.
Is a CPU (central processing unit) that performs various calculations, and 10 is C
RO storing programs for various operations performed by PU9
M (read only memory), 11 is a sensor signal processing unit that processes sensor signals of the azimuth sensor 1, distance sensor 2, etc. 12 is the azimuth sensor 1, distance sensor 2, GPS receiver 4, CD-ROM drive 5, etc. Data and CPU
A memory (DRAM) for storing the operation result in 9 and 13
Is a backup memory (SRA) for holding necessary data even when the power supply to the apparatus main body 8 is stopped.
M), 14 is a memory (kanji, font ROM) in which patterns such as characters and symbols to be displayed on the liquid crystal display 7A are stored, and 15 is for forming a display image based on map data or current position data of the vehicle. The image processor 16 stores map images generated by the image processor 15, current position data and kanji, kanji such as town names and road names output from the font ROM 14, and an image to be displayed on the liquid crystal display 7A by combining fonts. A memory (VRAM) 17 for converting is an RGB conversion circuit for converting the output data of the VRAM 16 into a color signal, and the color signal is output from the RGB conversion circuit 17 to the liquid crystal display 7A. 18 is a communication interface.

FIG. 6 is a diagram showing a format of data stored in the CD-ROM 6. In FIG. 6, 2
0 is a disk label, 21 is a drawing parameter, 22 is map leaf management information, and 23 is a map leaf. This map leaf 23 stores background data, character data, road data, etc., and is a topographic map of Japan. Data is stored for each unit map that is divided by latitude and longitude. In the map leaf, data that roughly describes a wide area to data that describes a narrow area in detail are set.

Each map leaf 23 is composed of map display levels A, B and C which describe the same area. The map display levels A, B and C are described in more detail as B than A and C as B. Each map display level A, B, C is composed of map display level management information and a plurality of units. Each unit describes a divided area obtained by dividing the area of each map display level into a plurality of areas.
It consists of a character layer, a background layer, a road layer, an option layer, and so on. Place names, road names, facility names, etc. displayed on the map are recorded in the character layer, and data for drawing roads, facilities, etc. are recorded in the background layer.
Further, in the road layer, as shown in FIG. 7, data on coordinate points (nodes) and lines (links) that describe roads including intersections, for example, node numbers of nodes, latitude and longitude, link numbers of links, The link distance and the like are stored. In FIG. 7, circles indicate nodes, and lines between the nodes indicate links. The black circle with the node number 4 indicates an intersection node. The data recorded in the road layer is not directly involved in the map display and is used as road network information for map matching.

In FIG. 6, reference numeral 24 is route search data, and search data is 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, assumed link transit time (link cost) data 26, and route display data 27.

As shown in FIG. 8, the node connection data 25 is data indicating which node each of the nodes a to g, x, and y is connected to. For example, for the node c, the nodes a, d, and It is data indicating that it is connected to f and y. Further, as shown in FIG. 8, the link cost data 26 indicates the link cost of the link between the nodes. For example, the link cost of the link between the node a and the node c is “5”, It indicates that the link cost of the link between a and node b is “10”, and the link cost of the link between node a and node d is “20”. The link cost is obtained from link cost = link distance / set speed, and the set speed is set according to the road type and the road width, for example, as shown in FIG. As the route display data 27, data for displaying the route selected by the route search on the display map is recorded.

The operation of the above configuration will be described below. The output of the direction sensor 1 and the output of the distance sensor 2 are sent to the CPU 9 via the sensor signal processing unit 11. The CPU 9 calculates the current position of the vehicle, and obtains the latitude and longitude of the current position. In the CPU 9, G
The current position is corrected based on the data sent from the PS receiver 4 via the communication interface 18. Based on the current position obtained in this way, the map data of the unit corresponding to the current position is stored in the CD-ROM drive 5.
Is read from the CD-ROM 6 by this and this map data is stored in the memory (DRA) via the communication interface 18.
M) 12 is stored.

A part of the map data stored in the DRAM 12 is read by the CPU 9 and the image processor 15
Is converted into image data and written in the image memory 16. The image data stored in the image memory 16 is converted into a color signal by the RGB conversion circuit 17, and the liquid crystal display 7A is displayed.
A map of a predetermined range centering on the current position is displayed. If the map data read from the DRAM 12 includes character codes and symbol codes, the patterns corresponding to these character codes and symbol codes are read from the Kanji and font ROM 14, and the liquid crystal display 7
Characters such as place names and symbols such as schools are displayed in A along with the map. Then, the current position displayed on the liquid crystal display 7A is sequentially changed based on the traveling speed and the traveling azimuth sequentially obtained as the vehicle travels.

Next, the route search operation will be described with reference to FIGS.
This will be described with reference to the flow chart shown in FIG.

As shown in FIG. 12, the destination is set in step S11. The destination can be set by, for example, inputting the address of the destination from the touch panel 7B, designating a point on the map displayed on the liquid crystal display 7A, or the place name displayed on the liquid crystal display 7A. This is done by selecting the desired place name from the index. In step S12, it is determined whether to start the route search. This determination is made based on whether or not the route search switch on the touch panel 7B of the display device 7 has been operated. If it is determined in step S12 that the route search switch has been operated, the process proceeds to step S13, where a route search is performed. This route search is as shown in FIG.
Origin node (current position node) x to destination node y
The link cost of all the routes leading up to is added to select the route with the lowest link cost. In the case of FIG. 8, the link cost of the link x → a → c → d → f → g → y. Since the total (10 + 5 + 5 + 5 + 5 + 5 = 35) is the smallest, the route connecting the links x → a → c → d → f → g → y is selected. The route selected in step S13 of FIG. 12 is displayed in red, for example, on the display map of the display device 7 in step S14.

FIG. 13 shows step S13 of the route search in FIG. 12 in more detail. First, at step S21, a departure node and a destination node closest to the position of the departure point and the destination are selected. In FIG. 8, node x
Indicates that the node is selected as the starting node and the node y is selected as the destination node. Next, in step S22, the route search data including the departure node x is read from the CD-ROM 6, and in step S23, the route search on the departure side is performed. As described above, this route search selects the route with the lowest total link cost. Next, in step S24, as a result of the search in step S23,
It is determined whether or not the target node is connected. The distance from the starting point to the destination is relatively short, and CD-
When the destination node y is included in the data read from the ROM 6, it is determined as YES in step S24, but when the destination is far from the departure place, step S24 is performed.
In No, it is judged No, and the process proceeds to step S25.

In step S25, the route search data including the destination node y is read from the CD-ROM 6, and in step S26 the destination side route is searched. Step S27
Then, it is determined whether or not the route selected by the route search on the destination side in step S26 is connected to the search route on the departure side. If the result of this determination is NO, the search hierarchy is set to 1 in step S28 in FIG.
Rank up. If the read data in steps S22 and S25 is the route search data of layer 0, the rank is increased to layer 1 in step S28.
Next, in step S29, the starting node and the destination node are reset, and the process returns to step S22.

In FIG. 10, the distance between the departure place and the destination is long, and steps S24 and S27 in FIG.
It is a diagram that clearly shows the operation when it is determined to be no, and the route selected in the route search on the departure side is not connected to the destination node, and the route selected in the route search on the destination side is If the route searched in the departure route search is not connected, the route search data 28 of the layer 1 is read,
The departure node 29 and the destination node 30 are set. Tier 1
When the route indicated by the solid line is searched for by the route search in step S24, YES is determined in step S24 in FIG. 13, the process proceeds to step S30, the route from the departure point to the destination is configured in step S30, and the route is searched in step S31. The display data of the route is created and the route search is completed.

FIG. 14 shows a display example on the liquid crystal display 7A. In FIG. 14, reference numeral 31 indicates the own vehicle mark, and this own vehicle mark 31 indicates the current position and the traveling direction of the own vehicle. Reference numeral 32 indicates the route searched by the route search, 33 indicates the direction of the destination at the current position, and 34 indicates the distance from the current position of the own vehicle to the destination. Reference numeral 35 is a touch switch for displaying or erasing the distance to the destination on the liquid crystal display 7A.

[0017]

However, in the above conventional example, the calculated route is uniquely set with the link cost according to the road type and the road width. Therefore,
Since the link cost does not take into account the actual speed of passage, roads that are constantly congested or roads with high road ranks may be selected as routes that are difficult to pass, and the optimal route to the destination that suits the actual situation It can not be said.

The present invention solves the above-mentioned conventional problems, and it is possible to display a route in which the actual traffic condition is taken into consideration in the route search result on the display device. It is an object of the present invention to provide a route search display device capable of presenting an optimal route that matches.

[0019]

In order to achieve the above-mentioned object, the present invention provides an optimum route matching means for an actual passage speed based on a learning result of a route to a destination input by the destination inputting means. The route is searched and displayed on the display means.

As a result, it is possible to obtain the route search display device capable of presenting the optimum route suitable for the actual road condition to the driver.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a current position calculating means for obtaining the current position of the vehicle based on the traveling distance and the traveling direction of the vehicle, and a storage means for storing map data. Display means for displaying the map read from the storage means together with the current position of the vehicle corresponding to the current position obtained by the current position calculation means, destination input means for inputting a destination, and actual passage A means for learning the link cost based on the speed, a means for reflecting the learning result in the link cost of the route search, and a route from the current position of the vehicle to the destination based on the result, and the searched route Is provided on the display means, and by reflecting the actual traveling state in the link cost, it is possible to obtain a more suitable route search result. Having an iodine.

According to a second aspect of the present invention, in the above-described first aspect of the invention, the learning result of the link cost is limited to the highway and stored.

According to a third aspect of the present invention, in the above-mentioned first aspect of the invention, the learning result of the link cost is divided into time zones or days of the week and stored.

According to a fourth aspect of the invention, in the invention of the first aspect, the learning result of the link cost is divided into seasons and stored.

[0025] A fifth aspect of the present invention is the invention according to the first aspect, further comprising means for collecting the learned link costs as a database.

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) The basic configuration of the route search display device in this embodiment is the same as that of the conventional example as shown in the block diagram of FIG. 1, but in this embodiment, the current position is In addition to the calculation function, the function of learning the link cost based on the speed actually passed, the function of reflecting the learning result in the link cost of the route search, and the route from the current position of the vehicle to the destination based on the result However, the present invention is characterized in that it has a route search function for displaying the searched route on the liquid crystal display 7A which is a display means, and stores the link cost learning result in the DRAM 12.

With the above configuration, the link conversion processing operation by the CPU 9 will be described below with reference to the flowchart shown in FIG.

First, it is judged whether or not the own vehicle is matched with the road layer network (step S).
1). If NO, this process ends. In the case of YES, the average speed of passing the currently running link is obtained (step S2). Next, the link cost of the currently running link is selected from the search data (step S3). Next, the actual link cost is obtained from the average passing speed (step S4). This actual link cost is (Equation 1)
As is clear from the calculation formula, the actual link cost can be obtained by dividing the currently running link distance (link length) by the average speed when actually passing.

[0029]

[Equation 1]

Next, a new link cost is calculated by the formula shown in (Equation 2).

[0031]

[Equation 2]

The new link cost is set so as to change very slowly by the constants K and n. In particular, the relevant link costs should be temporarily independent of the state of transit at that time. In this way, a new link cost is obtained by learning the link cost, and this link cost is memorized. By rewriting the link cost that was uniquely defined by the road type and the road width, A link cost suitable for the running state can be generated (step S5). Therefore, if the route search shown in FIG. 12 is performed based on this result, a more optimal route can be displayed.

A concrete route search result will be described by comparing the conventional example shown in FIGS. 8 and 3 with the embodiment of the present invention.

In FIG. 8, if the starting point is x and the destination is y,
When the route from x to y is obtained, the optimum route is x → a → c
The total link cost of → d → f → g → y is 35 (10+
5 + 5 + 5 + 5 + 5 = 35).

When this is calculated based on the learned new link cost, the total link cost of the routes x → a → c → d → f → g → y calculated by the new link cost is 48 (8 + 12 + 5 + 5 + 13 + 5) as shown in FIG. = 48), which is not the optimum route. Therefore, the actual optimum route is 45 (8 + 1), which is the total link cost of x → a → c → y.
2 + 25 = 45).

Further, in rewriting the link cost, the conventional configuration has a list of link costs corresponding to the link numbers for each layer as shown in FIG. It can be configured. For example, link numbers 1 and 2 of layer 0 are link numbers 1 of layer 1
The link cost is the sum of the link numbers 1 and 2 of the layer 0. Since the associations are made in this way, as shown in FIG. 4, the learning result can be written as it is in layer 0, and even in layer 1 or above, it can be rewritten based on the result, and the route search ends in layer 0. It is possible to perform a route search suitable for the actual situation even when the level is raised to 1 or higher.

When rewriting the link cost, since the link cost varies depending on the time zone, the day of the week, and the season actually passed, the link cost table of FIG. 4 is divided into the time zone, the day of the week, and the season and stored. By doing so, a more appropriate route can be displayed. Further, the learning result of the link cost can be stored only in the expressway. FIG. 5 shows a diagram displaying a route calculated based on the learned link cost.

Moreover, since the range in which one driver actually acts is limited, the range in which data can be collected is also limited. Therefore, if the plurality of route search / display devices have a means for storing the learned data, it is possible to collect the link cost data more suitable for the actual condition in a wider range.

If an initial link cost is created based on the collected data, it is possible to provide a route search display device for performing a more optimal route search without learning the link cost.

As described above, according to the above embodiment, the result searched by the route search is not uniquely calculated based on the road rank and the road width, but the actual traveling state is reflected in the link cost. By doing so, it is possible to obtain a route search result that better matches the actual situation.

[0041]

As described above, according to the present invention, it is possible to provide the driver with the optimum route from the current position of the vehicle to the destination, which is more suitable for the road traffic condition.

[Brief description of drawings]

FIG. 1 is a block diagram showing a traveling position display device including a route search display device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a link cost conversion processing operation in the same route search display device.

FIG. 3 is an explanatory diagram showing that a search is performed based on a result of learning a link cost in the same route search display device.

FIG. 4 is an explanatory diagram showing a link cost table in the route search display device.

FIG. 5 is an explanatory view showing a route search result calculated by the route search display device.

FIG. 6 is an explanatory diagram showing a format of a CD-ROM in a route search and display device according to a conventional example and the present embodiment.

FIG. 7 is an explanatory diagram showing road data recorded in a CD-ROM in the route search display device.

FIG. 8 is an explanatory diagram of a route search method in the route search display device.

FIG. 9 is an explanatory diagram showing set speeds for link cost calculation in the same route search display device.

FIG. 10 is an explanatory diagram of a hierarchical structure for route search in the route search display device.

FIG. 11 is a diagram showing a link cost table in a conventional route search display device.

FIG. 12 is a flowchart for explaining a route setting operation in the route search display device.

FIG. 13 is a flowchart for explaining a route search operation in the route search display device.

FIG. 14 is an explanatory view showing a route search result in the route search display device.

[Explanation of symbols]

 1 Direction Sensor 2 Distance Sensor 4 GPS Receiver 5 CD-ROM Drive 6 CD-ROM 7 Display / Operation Unit 7A Liquid Crystal Display 7B Touch Panel 8 Device Main Body 9 CPU 10 Program ROM 11 Sensor Signal Processor 12 DRAM 13 SRAM 14 Kanji / Font ROM 15 image processor 16 VRAM

Claims (5)

[Claims] 1. Corresponding to a present position calculating means for obtaining a present position of the vehicle based on a traveling distance and a traveling direction of the vehicle, a storing means for storing map data, and a present position obtained by the present position calculating means. Display means for displaying the map read from the storage means together with the current position of the vehicle, destination input means for inputting the destination, means for learning the link cost based on the speed actually passed, and learning A means for reflecting the result in the link cost of the route search and a route search means for searching the route from the current position of the vehicle to the destination based on the result and displaying the searched route on the display means are provided. Route search display device. 2. The route search display device according to claim 1, wherein the learning result of the link cost is stored only in the expressway. 3. The route search display device according to claim 1, wherein the learning result of the link cost is divided and stored in a time zone or a day of the week. 4. The route search display device according to claim 1, wherein the link cost learning result is divided into seasons and stored. 5. The route search display device according to claim 1, further comprising means for collecting learned link costs as a database.