JPH0758199B2 - In-vehicle navigator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle-mounted navigator that corrects a detection error of a self-contained navigation sensor based on map data.

2. Description of the Related Art Conventionally, this type of vehicle-mounted navigator searches a plurality of candidate routes in which the vehicle may currently travel from a wide range of map data stored in advance on a tape or a disk, and searches for these candidate routes. The actual traveling route is determined by comparing the current positions.

However, in the above-mentioned conventional vehicle-mounted navigator, when many roads are densely present in the map data, many candidate routes must be searched, and therefore the vehicle is actually located. There is a problem that the route to be taken cannot be determined at high speed, the correction section becomes long, and the accuracy of the current position of the vehicle deteriorates.

In view of the above problems, it is an object of the present invention to provide a vehicle-mounted navigator that can determine a route where a vehicle is actually located at high speed and can improve the accuracy of the current position of the vehicle.

Means for Solving the Problems In order to achieve the above object, the present invention provides a table in which road data passing through the area is stored for each area into which the map data is divided in detail, and the traveling direction information of the vehicle is stored. An area in which the vehicle exists is estimated from the travel distance information, a plurality of candidate roads in which the vehicle may travel in the estimated area are searched from the table, and the vehicle travels from the searched candidate roads. The most probable road is determined, and the current position of the vehicle is determined based on the determined road, the traveling direction information of the vehicle, and the traveling distance information.

With the above-described configuration, the present invention corrects the current position of the vehicle by dividing the map data in detail, so the correction frequency increases,
Therefore, the route on which the vehicle is actually located can be determined at high speed, and the accuracy of the current position of the vehicle can be improved.

EXAMPLES Examples of the present invention will be described below with reference to the drawings. First
FIG. 1 is a functional block diagram showing an embodiment of a vehicle-mounted navigator according to the present invention, FIG. 2 (a) is a diagram for explaining the concept of meshes on a map, and FIG. 2 (b) is a wide area mesh. 2 is an explanatory diagram of road network data, FIG. 2 (c) is an explanatory diagram of a detailed mesh road pointer table, and FIG.
3 is a flowchart for explaining the operation of the vehicle-mounted navigator of FIG. 1.

In FIG. 1, 1 is a direction sensor for detecting the traveling direction of the vehicle, 2 is a distance sensor for detecting the traveling distance of the vehicle,
An area 3 is used to calculate the traveling direction and the current position of the vehicle based on the traveling direction and the traveling distance respectively detected by the direction sensor 1 and the distance sensor 2, and the area where the vehicle is estimated to exist based on the error estimation values of the sensors 1 and 2. It is an estimated direction / existing area calculation means for calculating

Reference numeral 4 is an estimated area overlapping mesh calculation means for calculating one to a maximum of four detailed mesh numbers in which this estimated area overlaps with the mesh on the map of FIG. 2 (a), and 5 is shown in FIG. 2 (b). 2 (c) is a detailed mesh road pointer table showing the storage start position of the road data of each detailed mesh, which is stored in the wide area mesh road network data of FIG.

Reference numeral 7 denotes a wide area mesh road network data storage unit which stores road data as shown in FIG. 2 (b).

Reference numeral 6 is a candidate road for extracting road data included in the detailed mesh from the detailed mesh road pointer table 5 and reading data of a candidate road passing through the estimated area from the wide area mesh road network data storage unit 7 based on this road data. It is a search means.

The reference numeral 8 indicates the route that has traveled so far from the estimated position and direction of the vehicle from the estimated direction / existing area calculation means 3, and the vehicle is most likely to travel from the candidate road read by the candidate road search means 6. The coincidence determination means 9 which selects by weighting high roads is a display control means which reads map data from the auxiliary storage means 12 according to the input information from the operation unit 13 and displays it on the display unit 11.

Reference numeral 10 determines the vehicle position from the estimated direction / presence area calculation means 3 and the road selected by the coincidence determination means 8 to determine the vehicle position to the position closest to the estimated position on the road. It is a current position fixing means for correcting the current position and the direction based on the position, the estimated position and the direction of the road to determine the fixed position information.

Reference numeral 12 is an auxiliary storage means such as a tape or disk in which a wide range of map data is stored as shown in FIG.
It is an operation unit for a vehicle to input a position and the like.

Next, the operation of the above embodiment will be described with reference to FIG.

First, in FIG. 1, when the current vehicle position is input from the operation unit 13, a map search mode selection command is input to the display control means 9 and the place name list is displayed on the display unit 11. When one of the place names is selected via the operation unit 13 in this state, the display control means 9 reads the map data of the place name from the auxiliary storage means 12 into the wide area mesh road network data storage unit 7 and decodes it. Display on the display unit 11.

Then, when a more accurate current position of the vehicle is input from the operation unit 13 in this display state, this position is displayed on the display unit 11 so as to be superimposed on the map (display control means 9).

In this display state, when the traveling direction and the traveling distance are respectively input from the direction sensor 1 and the distance sensor 2, the traveling direction and the current position of the vehicle are calculated and the error of the sensors 1 and 2 is calculated in step 31 shown in FIG. By the estimated value,
An area where the vehicle is estimated to exist is calculated (estimated direction / existing area calculation means 3).

Next, in step 32, the detailed mesh number on which the estimated area overlaps the detailed mesh on the map is calculated to be one to a maximum of four (estimated area overlapping mesh calculating means 4), and the currently displayed map is calculated. The map data in the vicinity of is read from the auxiliary storage means 12 and stored in the detailed mesh road pointer table 5 and the wide area mesh road network data storage unit 7 (display control means 9).

When the detailed mesh number is calculated, in the following step 33,
The storage position of the road data included in the detailed mesh is fetched from the detailed mesh road pointer table 5, and as a result, the wide area mesh road network data storage unit 7 is obtained.
The data of the candidate road that passes through the estimated area is read from (candidate road search means 6).

In step 34, the estimated path and direction of the vehicle from which the road has traveled so far are grasped, and by weighting this candidate road, the road with the highest possibility of traveling is selected. If it is possible to return and select, the process proceeds to step 35 (coincidence determination means 8).

In step 35, the vehicle position is determined to be the closest position on the road from the estimated position based on the estimated position and direction of the vehicle and the selected road, and the current position and direction are determined based on the determined position, the estimated position, and the direction of the road. The corrected position information is corrected and the fixed position information is determined (current position determining means 10).

Next, in step 36, the display unit 11 superimposes the current position and direction of the vehicle on the map based on the determined position information.
, And returns to step 31.

After this correction, the previous fixed position information is held and displayed on the display unit 11 until the next correction is completed.

Therefore, according to the above-described embodiment, when the area where the vehicle exists is estimated, the number of the detailed mesh including the area is calculated, and the road data passing through the detailed mesh can be extracted at high speed, so that the correction is performed frequently. Therefore, the accuracy of the current position of the vehicle can be improved.

Effect of the Invention As described above, the present invention provides, for each area obtained by dividing map data in detail, a table in which road data passing through the area is stored, and by the traveling direction information and traveling distance information of the vehicle, The area in which the vehicle exists is estimated, a plurality of candidate roads in which the vehicle may travel in the estimated area are searched from the table, and the vehicle is most likely to travel from the searched candidate roads. The road is determined, and the current position of the vehicle is determined based on the determined road, the traveling direction information of the vehicle, and the traveling distance information.The vehicle route can be determined at high speed, and the correction frequency is high. Therefore, the accuracy of the current position of the vehicle can be improved.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a vehicle-mounted navigator according to the present invention, FIG. 2 (a) is a diagram for explaining the concept of a mesh on a map, and FIG. 2 (b) is FIG. 2 (c) is an explanatory view of a detailed mesh road pointer table, and FIG. 3 is a flowchart for explaining the operation of the vehicle-mounted navigator of FIG. 1 ... Direction sensor, 2 ... Distance sensor, 3 ... Estimated direction existence area calculation means, 4 ... Estimated area overlapping mesh calculation means, 5 ... Detailed mesh road pointer table, 6 ...
Candidate road search means, 7 ... Wide area mesh road network data storage section, 8 ... Match determination means, 9 ... Display control means, 10 ... Current position determination means, 11 ... Display unit, 12 ... Auxiliary storage means , 13 …… Operation unit.

Claims (1)

[Claims] 1. A road network data storage unit for storing road data of a wide area, and a pointer for storing, for each area obtained by dividing the wide area into a plurality of areas, position information storing road data passing through the area. A table, a means for estimating an area in which the vehicle exists based on the traveling direction information and traveling distance information of the vehicle, and a pointer table for a plurality of candidate roads in which the vehicle may travel in the area estimated by the estimating means. And means for searching from road network data, means for determining the most likely road on which the vehicle will travel from the plurality of searched candidate roads, traveling direction information and travel distance information for the determined road and vehicle A vehicle-mounted navigator having means for determining the current position of the vehicle.