JPH01277714A - Navigation apparatus for vehicle - Google Patents

Abstract

PURPOSE:To eliminate that the position of one's own car on a map becomes wholly obscure, by appropriately changing over the first and second map matching means for matching the present position of one's own car on the basis of both of an approximate map and a detailed map. CONSTITUTION:In usual, the present position of one's own car is matched on the basis of a detailed map by the second map matching means 6 and the result thereof is displayed on a display means 7. When the present position of one's own car becomes obscure by the second map matching means 6, the display by a display means 7 is changed over to the first map matching means 5, which performs the matching of the present position of one's own car on the basis of an approximate map, by a control means 8 and, when the present position of one's own car is specified by the first map matching means 5, the position of one's own car is reset to the detailed map at the specified position and the matching result by the second map matching means is again displayed on the display means 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is a vehicle navigation device, in particular, a method for storing in advance the current position of the own vehicle estimated by the own vehicle position estimating means using a direction detecting means and a distance detecting means. The present invention relates to a vehicle navigation device that guides the driving of a vehicle by matching roads on a map.

(Prior art) In recent years, the current position of the own vehicle relative to a reference position is estimated using a direction sensor and distance sensor that utilize geomagnetism, and the estimated current position of the own vehicle and a map of the surrounding area are displayed on a display. A vehicle navigation system has been developed that uses so-called dead reckoning navigation, which displays information on the screen to guide the travel of the own vehicle. By the way, in the dead reckoning navigation described above, the current position of the own vehicle relative to the reference position is estimated based on the direction obtained by the azimuth sensor and the travel distance obtained by the distance sensor. As the vehicle moves away from the vehicle's location, measurement errors in distance and direction accumulate, resulting in a decline in the accuracy of recognition of the vehicle's current location. As a means to deal with such a situation, for example, Japanese Patent Application Laid-Open No. 61-20931
As described in Publication No. 6, Map Matching corrects the current position of the vehicle estimated by dead reckoning navigation to the above position when the vehicle passes a position with a characteristic road shape, such as an intersection. A technique called .

(Problem to be Solved by the Invention) By the way, when map matching is performed when the vehicle passes an intersection or a corner as in the above-mentioned prior art, for example, if the vehicle is driving in a city area with many intersections or corners, , there are many intersections and corners around the current position of the vehicle estimated by dead reckoning, so when matching the current position of the vehicle, the intersections and corners that the vehicle actually passed through must be There is a possibility that a situation may occur in which it becomes extremely difficult to identify the location of the vehicle, making map matching impossible, or the current location of the vehicle becomes completely unknown.

Accordingly, the present invention provides a vehicle navigation device that guides the travel of the vehicle by matching the vehicle's current position estimated by vehicle position estimating means to roads on a pre-stored map, in which major roads are represented. By performing map matching using a combination of a schematic map and a detailed map showing major roads and other roads, when it becomes difficult to identify the current position of your vehicle on the detailed map,
A vehicle that performs map matching based on a schematic map to efficiently specify the current position of its own vehicle, and displays this identified vehicle position on a detailed map so that map matching can be performed again based on the detailed map. The purpose is to provide a navigation device for

(Means for Solving the Problems) In order to solve the above problems, a vehicle navigation device according to the present invention is characterized in that it is configured as follows.

That is, as shown in FIG. 1, vehicle position estimating means 3 estimates the current position of the vehicle relative to the reference position based on the direction data obtained by the direction detecting means 1 and the distance data obtained by the distance detecting means 2. and a map information storage means 4 in which map information is stored in advance, and compares the current position of the vehicle estimated by the vehicle position estimation means 3 with the map information stored in the map information storage means 4. This is a vehicle navigation device that guides the driving of the vehicle by matching the current location of the vehicle to roads on a map, and the map information includes a schematic map showing major roads, major roads and other roads. a first map matching means 5 for matching the current position of the own vehicle based on the detailed map; and a second map matching means 5 for matching the current position of the own vehicle based on the detailed map. A map matching means 6, a display means 7 which normally displays the matching result by the second map matching means 6, and a display means 7 which displays the matching result by the first map matching means 5 when the own vehicle position is unknown by the second map matching means 6. and control means 8 for resetting the own vehicle position on the detailed map at that position and displaying the matching result by the second map matching means 6 when the own vehicle position is specified by the first map matching means 5. It is characterized by having the following.

(Function) According to the above configuration, normally, the second map matching means 6 matches the current 7° right position of the own vehicle based on the detailed map, and the result is displayed on each display means. Then, when the second map matching means 6 determines that the current position of the own vehicle is unknown and is 8 degrees, the control means causes the display means (7) to display the current position of the own vehicle based on the road map. When the current position of the own vehicle is specified by the first map matching means 5 which matches the current position, the own car position is displayed on the detailed map at the specified position. After resetting, the second map matching is performed again, and the matching result by the 7° means is displayed on the display means.

(Example) Examples of the present invention will be described below.

FIG. 2 is a control system diagram of the vehicle navigation device according to the present embodiment. A distance sensor 12 as a distance detecting means that outputs a pulse signal every time the vehicle travels to detect the distance traveled by the vehicle, and map information such as a map showing information necessary for travel guidance of the vehicle such as roads and buildings. A map information storage device 13 in which map information is stored, a road 1 as map information stored in the map information storage device 13, and a display device 14 composed of a CRT or the like to display the map on a display screen.
and a control circuit 15.

The control circuit 15 includes an arithmetic circuit 16, a memory circuit 17 connected thereto, and an input/output interface 1.
8, and the geomagnetic sensor 11, distance sensor 12, map information storage device 13, and display 14 are connected to the arithmetic circuit 16 via the input/output interface 18.

Therefore, a signal indicating the traveling direction of the own vehicle from the geomagnetic sensor 11 and a signal indicating the traveling distance of the own vehicle from the distance sensor 12 are input to the arithmetic circuit 16 via the input/output interface 18. Accordingly, the arithmetic circuit 1
In step 6, the estimated position of the own vehicle is calculated, and the calculation result is temporarily stored in the storage circuit 17. Also,
The control circuit 16 extracts a map around the estimated position of the own vehicle detected as described above from the map information storage device 13, matches the estimated position of the own vehicle on the map, and displays it on the display. It is configured to be displayed on 14 screens. Note that the map information storage device 13 includes, for example, a CD-ROM and a CD-ROM for reproducing the CD-ROM.
It consists of a D drive (player).

Furthermore, in this embodiment, the map information storage means 13
For example, as shown in FIG. 3 (I), the map information stored in the map A is a road map A in which only major roads such as National Route A and expressway exits (indicated by thick solid lines in the figure) are shown; Similarly, as shown in Figure 3 (II), although it shows the same area as the road map A, it covers not only major roads such as national highway A and expressway exits, but also prefectural road C (indicated by the thin solid line in the figure). A detailed map B showing detailed roads is provided. Also,
A large number of nodes N. The information is entered in advance.

Therefore, in this embodiment, the control circuit 15 executes the matching control operation using the condylar road map A and the matching control operation using the detailed map B simultaneously and in parallel. , the matching results based on the detailed map B are displayed as images on the display 14.

Next, the specific operation of this embodiment will be explained according to the flowchart of FIG.

First, in step S, detailed map B (Fig. 3 (
The matching process is executed based on the reference position on the detailed map B (see the latest The current position of the vehicle relative to the matching position (matching position), ie, the estimated position PO, is calculated. Note that when performing matching based on this detailed map B, since the road density is high, it is necessary to perform matching processing closely in order to frequently search for intersections and corners. Therefore, as a matching parameter suitable for this matching, for example, the sampling time interval for sampling the pulse signal from the distance sensor 12 is set short to perform close matching. Then, in step S2, the transport route map A (third
Matching processing is executed based on the following (see figure (I)),
An estimated position P of the own vehicle on the schematic map A is calculated.

Note that when matching is performed based on this transport path map A, the road density is relatively low, so in order to perform matching suitable for this, the sampling time for sampling the pulse signal from the distance sensor 12, for example, is set relatively long. do.

Then, in step S3, the likelihood of the estimated position Po of the own vehicle on the detailed map B is evaluated, and then in step S4, it is determined whether or not the estimated position Po is likely, and if YES, step S, Estimated position P. on detailed map B and display this on display 1.
4 (see FIG. 3 (II)), and in step S6, the estimated position P1 of the own vehicle on the schematic map A estimated in step S2 is reset to Po. If the determination is NO in step S4, the estimated position P1 of the own vehicle on the schematic map A estimated in step S2 is displayed on the display 14 in step S7 (see FIG. 3 (I)). . Then, in step S8, by matching based on the route map A, the rough map A
It is determined whether the own vehicle has arrived at a predetermined node N provided above. When the determination is YES, the estimated position P of the own vehicle on the detailed map B is determined. is reset to the position of the node N on the schematic map A.

If the determination is No, matching based on the route map A is executed again in step 9.

As described above, in this embodiment, if it becomes difficult to specify the current position of the own vehicle during matching based on the detailed map B, matching based on the transport path map A can efficiently identify the current position of the own vehicle. It becomes possible to specify the current position of the vehicle and perform matching again based on the detailed map B using the specified vehicle position as a reference.

(Effects of the Invention) As described above, according to the vehicle navigation device according to the present invention, the second map matching means normally performs matching based on the detailed map, and the result is displayed on the display means. Therefore, when the current position of the own vehicle becomes unknown by the second map matching means, the first map matching means performs matching based on the route map, and the first map matching means determines the current position of the own vehicle. is specified, the own vehicle position on the detailed map is reset at the specified position and the matching result by the second map matching means is displayed on the display means again. When performing matching based on a detailed map when driving in a high city area, it is possible to avoid a situation where the position of the own vehicle becomes completely unknown.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall configuration of a vehicle navigation device according to the present invention, Figs. 2 to 4 show embodiments of the present invention, and Fig. 2 is a control system diagram of the navigation device according to the present embodiment. , FIG. 3 is a schematic diagram showing a transport path map and a detailed map, and FIG. 4 is a flowchart showing the control operation of map matching by the control circuit. 11... Orientation detection means (geomagnetic sensor), 12...
distance detection means (distance sensor), 13... map information storage means (map information storage bag), 15... first and second map matching means, display means, control means (control circuit).

Claims (1)

[Claims] (1) Vehicle position estimation means for estimating the current position of the vehicle relative to a reference position based on the direction data obtained by the direction detection means and the distance data obtained by the distance detection means, and a map in which map information is stored in advance. information storage means, and compares the current position of the own vehicle estimated by the above-mentioned own vehicle position estimation means with the map information stored in the above-mentioned map information storage means, and maps the current position of the own vehicle onto the road on the map. A vehicle navigation device that guides the driving of a vehicle by matching, and is provided with a schematic map showing major roads and a detailed map showing main roads and other roads as the map information. , a first map matching means for matching the current position of the own vehicle based on the above-mentioned general map, a second map matching means for matching the current position of the own vehicle based on the above detailed map, and usually a second map matching means. a display means for displaying the matching result by the second map matching means, and when the vehicle position is unknown by the second map matching means, the display is switched to the display by the first map matching means, and the first map matching means displays the vehicle position. a control means for resetting the own vehicle position on the detailed map at that position and displaying the matching result by the second map matching means when the vehicle position is specified. .