JPH09325038A - Method and apparatus for searching for route in car navigation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reach a destination quickly by reducing the number of times of right turns as much as possible. SOLUTION: A route-searching device 10 searches for routes from a start (start point) S to a destination (end point) E based on a map data M, the start S and destination E, and selects an optimum one. The route-searching device 10 is composed of a route-searching part 11 and a right turn.left turn-judging part 12. The route-searching part 11 searches for a plurality of reputes of a short distance from the start S to the destination E among many routes from the start S to the destination E. The right turn.left turn judging part 12 judges right turns and left turns of the plurality of routes searched by the route- searching part 11, and selects one route of a minimum count of right turns among the searched plurality of routes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a car navigation system, and more particularly to a route search method for the car navigation system.

[0002]

2. Description of the Related Art As is well known, a car navigation system is a positioning system mounted on a vehicle, and when a driver (user) or the like inputs a departure place and a destination from an input device, the car navigation system starts from the departure place. The route to the destination is searched, the searched route is displayed on the map displayed on the display screen of the display device, and the GPS (global positioning system) is displayed.
) A positioning system that displays the current vehicle position based on the radio waves received from satellites. Therefore, the car navigation system is roughly composed of a route search unit and a current position calculation unit. The route search unit searches for a plurality of routes having a short distance from the starting point to the destination from among a large number of routes from the starting point to the destination. The user
One route which seems to be appropriate is selected from the plurality of routes searched.

[0003]

As described above, the route searching section only searches for a plurality of routes from the starting point to the destination, and the user is considered to be preferable from among these routes. You have selected two routes. However, the route selected by the user is not always the optimal route. The reason will be described below.

Generally, when a vehicle makes a right turn or a left turn by interrupting an oncoming traffic, a straight ahead vehicle of the oncoming traffic must be prioritized. Especially in Japan, when trying to make a right turn, priority is given to a straight-ahead vehicle and a left-turn vehicle of the traffic facing each other. As a result, it takes longer to make a right turn than to make a left turn. However, conventionally, the time difference generated when making a right turn or a left turn is not considered.

Therefore, in view of the above-mentioned conventional problems, an object of the present invention is to search for a route of a car navigation system that enables a destination to be reached earlier by reducing the number of right turns as much as possible. A method and a route search device are provided.

[0006]

According to the present invention, a route search method for a car navigation system for searching a route from a starting point to a destination is selected from a large number of routes from the starting point to the destination. , The step of searching for multiple routes with a short distance from the starting point to the destination, and determining the right turn and right turn of these searched routes, and the route with the smallest number of right turns among the searched routes And a step of selecting a route search method for a car navigation system.

Further, according to the present invention, in a route search device for a car navigation system that searches for a route from a starting point to a destination, the route from the starting point to the destination is selected from a number of routes from the starting point to the destination. A route search unit that searches for multiple routes with a short distance to the ground and a right turn and a right turn of the searched multiple routes are selected, and the route with the smallest number of right turns is selected from the searched multiple routes. A route search device for a car navigation system having a right turn / left turn determination unit is obtained.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 2, it is a block diagram showing a hardware configuration of a car navigation system for realizing a route search method according to an embodiment of the present invention. The illustrated car navigation system includes a CD-ROM 21, an input device 22, a display device 23, and a read-only memory (RO).
M) 24 and a central processing unit (CPU) 25, which are connected to each other via a communication bus 26.

The CD-ROM 21 stores map data. The input device 22 is a departure point (start point) and a destination point (end point).
Is for entering. The display device 23 displays the map data stored in the CD-ROM 21 on the display screen,
The starting point and the destination, which are input from the input device 22, the selected route described later, and the current position of the vehicle are displayed.
The ROM 24 stores a route search program and a current position calculation program. CPU25 is ROM24
A route search as will be described later is performed according to the route search program stored in, and the current position of the vehicle is calculated according to the current position calculation program. That is, CPU 25 and R
The combination with the OM 24 works as a route search device and a current position calculation device described later.

A route search device 10 according to an embodiment of the present invention will be described with reference to FIG. The illustrated route search device 10 is based on the map data M stored in the CD-R0M 21 (FIG. 2) and the starting point (start point) S and the destination (end point) E input from the input device 22 (FIG. 2). , A device that searches for a route from a starting point S to a destination E and selects an optimum route.

The route search device 10 comprises a route search unit 11 and a right / left turn determination unit 12. Route search unit 11
Searches for a plurality of routes having a short distance from the starting point S to the destination E from among many routes from the starting point (start point) S to the destination (end point) E.

The operation of the route search section 11 will be described in detail with reference to FIG.

The route search unit 11 inputs a starting point (departure point) S (step S1), and subsequently inputs an ending point (destination) E (step S2). The route search unit 11 selects a point on the link (start point on the link) S _l closest to the start point S (step S3), and then selects a point on the link (end point on the link) E _l closest to the end point S. (Step S4).
Here, the intersection represented by the map data is called a node.
Next, the route search unit 11 selects a node (start point node) that is the closest to the on-link end point E _l and is the closest to the on-link start point S _l as the latest node (step S5). The route search unit 11 determines whether or not the on-link end point E _l exists on the link connecting to the latest node (step S).
6). Here, if it exists (Yes in step S6),
The route search process ends. If it does not exist (step S
No of 6), the route search unit 11 determines whether or not there is an adjacent node that has not been selected (step S7). If there is no adjacent node that has not been selected (step S
No. 7), the route search unit 11 determines whether the latest node is the start node (step S8). If the latest node is the start node (Yes in step S8), the road is not connected (step S9), and the user is notified to that effect. The latest node is not the start node (step S
No of 8), the route search unit 11 returns to the previous node (step S10) and returns to step S7. If there is an adjacent node that has not been selected (Yes in step S7)
s), the route search unit 11 selects the closest node as the next latest node (step S11), and returns to step S6.

Returning to FIG. 1, the right / left turn judging section 12
In this way, the right and left turns of the plurality of routes searched by the route search unit 11 are determined, and the route with the smallest number of right turns is selected from the plurality of routes searched. The selected optimum route is displayed on the map on the display screen of the display device 23.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes and modifications can be made without departing from the spirit of the present invention.

[0017]

As is apparent from the above description, according to the present invention, the route with the smallest number of right turns is selected as the optimal route from the plurality of routes searched by the route search unit. , It will be possible to reach the destination sooner. For example, in the case of a TA-Q-BIN car, the departure point and the arrival point that is the final destination are the same. By mounting the route search device according to the present invention on such a vehicle, the number of right turns can be reduced, and more efficient delivery becomes possible. In addition, if the route search device according to the present invention is installed in a vehicle that uses the same course many times a day, such as a delivery vehicle that travels through a chain of convenience stores, more efficient delivery is possible. Becomes

[Brief description of drawings]

FIG. 1 is a block diagram showing a route search device for a car navigation system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a hardware configuration of a car navigation system that realizes a route search method according to an embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of a route search unit used in the route search device for the car navigation system shown in FIG.

[Explanation of symbols]

 10 route search device 11 route search unit 12 right / left turn determination unit

Claims (2)

[Claims] 1. A route search method for a car navigation system, which searches for a route from a starting point to a destination, wherein a route from the starting point to the destination is selected from a number of routes from the starting point to the destination. Determining a right turn and a right turn of the searched plurality of routes,
Selecting a route having the smallest number of right turns among the searched routes, the route searching method for a car navigation system. 2. A route search device for a car navigation system that searches for a route from a starting point to a destination, from a plurality of routes from the starting point to the destination, from the starting point to the destination. A route search unit that searches for a plurality of routes with a short distance, and a right turn and a right turn of the searched plurality of routes,
A route search device for a car navigation system, comprising: a right turn / left turn determination unit that selects a route with the smallest number of right turns among the searched routes.