WO2008136566A1

WO2008136566A1 - Apparatus and method for guide crossroad in navigation system

Info

Publication number: WO2008136566A1
Application number: PCT/KR2007/006403
Authority: WO
Inventors: Sang Hun Chang
Original assignee: Thinkware Systems Corporation
Priority date: 2007-05-07
Filing date: 2007-12-10
Publication date: 2008-11-13
Also published as: KR20080098724A; KR100871293B1

Abstract

An intersection guidance apparatus and method of a navigation system is provided. An intersection guidance method of a navigation system, the intersection guidance method comprising: retrieving a route to a destination set by a user and providing guidance about the retrieved route; and providing, when an intersection on the route is sensed, guidance information about the intersection based on a predetermined off-ramp lane with respect to the intersection.

Description

APPARATUS AND METHOD FOR GUIDE CROSSROAD IN NAVIGATION

SYSTEM

Technical Field

The present invention relates to a navigation system, and more particularly to an intersection guidance apparatus and method of a navigation system to provide guidance about an off-ramp in an intersection.

Background Art A navigation system is a system which provides information for driving of a transportation device, such as a vehicle, using an artificial satellite. The navigation system is automatic.

The navigation system receives predetermined data from a Global Positioning System (GPS) satellite above the Earth using a GPS receiver, and calculates its own location based on the received data.

The navigation system may provide a user with information about a current location of a vehicle based on calculated location information, perform routing to calculate a route to a desired destination, and provide guidance about the route.

In a navigation system, when a driver drives according to the route, a predetermined guidance target located ahead, for example, intersection, underground passage, high-level road, on-ramp, off-ramp, and the like, is retrieved. Hereinafter, the guidance target is referred to as 'intersection'. When approaching within a predetermined distance of the retrieved intersection, a driving direction in the intersection is provided through an image or voice. FIG. 1 is a diagram illustrating a road including an intersection. FIG. 2 is a diagram illustrating an equivalent shape of the road of FIG. 1 to describe based on a navigation system.

As illustrated in FIG. 1, the road corresponds to a side having a predetermined width. The intersection includes at least one off-ramp enabling a user to move from a main road to another road. An off-ramp lane which is an area to the off-ramp is previously defined in the intersection.

In a navigation-based system, a line corresponding to a center of road, hereinafter, referred to as 'center line', is extracted and used without using a side having a width. Accordingly, as illustrated in FIG. 2, the road including the intersection of FIG. 1 may be represented as the road center line. In the navigation system, the intersection is represented as a point where a road center line of the main road and a road center line of the off-ramp are crossed, and the point, hereinafter, referred to as 'cross point', is represented as a predetermined coordinate (X, Y).

Referring to FIG. 3, an intersection guidance method of a navigation system in a conventional art is described.

While providing guidance about a route to a destination, a location of an intersection PO is retrieved at regular intervals. The location of the intersection PO is retrieved by determining whether the intersection PO is located a predetermined distance ahead of a current location by referring to map data.

A route to the off-ramp of the intersection is provided using a guidance point previously defined based on the intersection PO. For example, the route to the off- ramp is provided at each guidance point such as 2 km P4, 1 km P3, 500 m P2, and 300 m Pl, cross point PO directly ahead, and the like.

As illustrated, an image or voice to notify about an access to the off-ramp is outputted at each guidance point PO, Pl, P2, P3, and P4 to provide guidance about the route to the intersection. After providing guidance about the access to the off-ramp, a route where the user moves is traced to determine whether the user enters the off-ramp. As a result of the determining, when it is determined that the user has deviated from the route, the route to the destination is retrieved again and provided.

When the user enters the off-ramp within an area A, a disadvantage due to the re-retrieval is not caused. The area A corresponds to an area to the cross point PO from the guidance point P4 where the guidance is started to be provided.

However, whether the user has deviated from the route is determined shortly after passing the cross point PO. Accordingly, when the user tries to enter the off-ramp in an area B after passing the cross point PO, although the area B is included in an area to the off-ramp, it may be recognized that the user has deviated from the route.

Accordingly, a re-retrieval error with respect to the route may be generated.

Currently, roads is extended or newly built due to an increase in cars, and intersections including a plurality of off-ramps increase. Since an intersection guidance method in a conventional art may not provide accurate guidance about an off- ramp, complaints of users increase and safe driving may be prevented.

Disclosure of Invention Technical Goals

The present invention provides an intersection guidance apparatus and method for a safer driving in an intersection when providing guidance about a route.

The present invention also provides an intersection guidance apparatus and method of a navigation system which reduces a re-retrieval error when providing guidance about a route to an intersection to accurately enter an off-ramp and for safe driving.

Technical solutions According to an aspect of the present invention, there is provided an intersection guidance method of a navigation system, the intersection guidance method including: retrieving a route to a destination set by a user and providing guidance about the retrieved route; and providing, when an intersection on the route is sensed, guidance information about the intersection based on a predetermined off-ramp lane with respect to the intersection.

According to another aspect of the present invention, there is provided an intersection guidance apparatus of a navigation system, the intersection guidance apparatus including: a map database storing an off-ramp lane for each intersection, the off-ramp lane indicating an area to an off-ramp, and the intersection including at least one off-ramp; and a control unit, when the intersection on a route to a destination set by the user is sensed, providing guidance information about a corresponding intersection based on the off-ramp lane stored in the map database.

Brief Description of Drawings FIG. 1 is a diagram illustrating a road including an intersection;

FIG. 2 is a diagram illustrating an equivalent shape of the road of FIG. 1 to be used in a navigation system; FIG. 3 is a diagram illustrating guidance points to provide guidance about an access to an off-ramp in an intersection to describe an intersection guidance method in a conventional art;

FIG. 4 is a diagram illustrating a configuration of an intersection guidance apparatus of a navigation system according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating an intersection guidance method of a navigation system according to an embodiment of the present invention; and

FIG. 6 is a diagram illustrating guidance points to provide guidance about an access to an off-ramp and an off-ramp lane in an intersection to describe an intersection guidance method according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

Hereinafter, embodiments of the present invention are described in detail by referring to the figures. An intersection guidance apparatus of a navigation system is described first.

FIG. 4 is a diagram illustrating a configuration of an intersection guidance apparatus of a navigation system according to an embodiment of the present invention.

The intersection guidance apparatus according to an embodiment of the present invention is applied to a navigation system including a Global Positioning System (GPS) module 10. The GPS module 10 receives a location signal from at least three GPS satellites and calculates its location.

The navigation system according to an embodiment of the present invention is a user terminal providing guidance about a route to a destination set by a user. Specifically, when approaching an intersection on the route, the navigation system separately provides guidance about an access to the intersection and off-ramp lane.

The intersection guidance apparatus includes a display unit 20, user interface 30, voice output unit 40, map database 50, route calculation unit 60, and control unit 70.

The map database 50 is included in a storage unit, not illustrated in FIG. 4, of the navigation system. The map database 50 includes map data of a national map and route guidance data associated with the map data. The storage unit stores a control program to control an entire operation of the navigation system including a route guidance function and intersection guidance function while providing guidance about the route.

Specifically, intersections included in the national map and an off-ramp lane of each of the intersections are checked. The map database 50 stores location information about the intersections and location information about the off-ramp lane of each of the intersections.

The intersection includes at least one off-ramp to enable the user to move from a main road to another road. An off-ramp lane of a predetermined distance to enable the user to enter the off-ramp from the main road is designated.

A point where the main road and off-ramp are met is referred to as a cross point. Since the off-ramp lane has the predetermined distance, a start point of the off-ramp lane and an end point of the off-ramp lane may exist. The start point is a point where the off-ramp lane starts and the end point is a point where the off-ramp lane ends.

That is, the map database 50 establishes a coordinate value of the cross point and a coordinate value corresponding to the start point and end point of the off-ramp lane with respect to each of the intersections.

The route calculation unit 60 ascertains a current location of the user using a GPS signal received from the GPS module 10, retrieves the route to the destination set by the user from the current location in the map data stored in the map database 50, and generates route information. The control unit 70 provides guidance about the route based on the route information generated in the route calculation unit 60. Also, when approaching the intersection on the route, the control unit 70 sequentially provides guidance about an access to the intersection and off-ramp lane based on the off-ramp lane of intersection stored in the map database 50. Also, the display unit 20 displays map information for the route guidance and a variety of contents according to each system operation. A Liquid Crystal Display (LCD) or Electro Luminescence (EL) may be used as the display unit 20.

The user interface 30 is for inputting a user command with respect to a route guidance function, for example, inputting a destination. The user interface 30 may be a touch pad formed integrally with the display unit 20, and provides a user graphic interface unit. Every menu environment associated with the route guidance function of the navigation system may be provided as a graphic screen through the display unit 20. A user command may be inputted by touching a particular location on the graphic screen using a stylus pen, fingers, and the like.

The voice output unit 40 provides voice guidance when providing guidance about the route. When approaching the intersection, the voice output unit 40 may provide voice guidance about the access to the intersection and off-ramp lane.

An intersection guidance method according to an embodiment of the present invention is described in detail with reference to FIG. 5.

FIG. 5 is a flowchart illustrating an intersection guidance method of a navigation system according to an embodiment of the present invention. FIG. 6 is a diagram illustrating guidance points to provide guidance about an access to an off-ramp and off-ramp lane in an intersection to describe an intersection guidance method according to an embodiment of the present invention.

When a user sets a destination with respect to a route guidance function of a navigation system, a current location is measured and a route to the destination is calculated. Map data based on the calculated route is embodied as an image or voice to provide guidance about the route.

As illustrated in FIG. 5, in operation SlO, an intersection located ahead in a driving direction is retrieved. For the intersection retrieval, it is determined whether a coordinate value of the intersection located a predetermined distance ahead from a current location, that is, a cross point PO, exists by referring to location information of the intersection and map data stored in a map database 50.

According to an embodiment of the present invention, as an example, an off- ramp is linked to a main road on the route.

When the cross point PO located the predetermined distance ahead is sensed in operation SlO, in operation S20, location information of the off-ramp lane with respect to the intersection is read, and guidance information notifying an access to the intersection, hereinafter, referred to as 'intersection access guidance', is outputted as an image or voice shortly before reaching the off-ramp lane.

As illustrated in FIG. 6, the location information of the off-ramp lane indicates a coordinate value of a start point and end point of the off-ramp lane based on the cross point PO. The off-ramp lane is linked to the off-ramp.

The intersection access guidance is repeatedly provided at regular intervals in an area ahead of the start point of the off-ramp lane. It is preferable that guidance pints Pl, P2, and P3 for the intersection access guidance may be located ahead of the start point of the off-ramp lane.

When it is assumed that the cross point PO is sensed at the guidance point P3 illustrated in FIG. 6, the intersection access guidance is first provided at the guidance point P3 where the cross point PO is sensed, and then the intersection access guidance is again provided at the guidance points Pl and P2.

The intersection access guidance notifies that the intersection is located ahead and provides guidance about a remaining distance from a current location to the cross point PO, for example, 'Yang-jea is located 2 km ahead'.

Referring again to FIG. 5, in operation S30, it is determined whether the current location approaches the start point of the off-ramp lane.

When the current location approaches the start point of the off-ramp lane as a result of the determining in operation S30, in operation S40, guidance information notifying about an area to the off-ramp lane, hereinafter, off-ramp lane guidance, is outputted as an image or voice from the start point to the end point.

The off-ramp lane guidance provides guidance about the off-ramp. The off- ramp lane guidance is repeatedly provided at regular intervals in the area to the off-ramp lane as illustrated in FIG. 6. Also, it is preferable that guidance points SP, SPl, SP2, and EP providing guidance about the off-ramp lane include at least two points in the area to the off-ramp lane.

When reaching the start point of the off-ramp lane, guidance information notifying about the start point of the off-ramp lane, for example, 'off-ramp lane is 2 km long from here', is outputted. When reaching the end point of the off-ramp lane, guidance information notifying about the end point of the off-ramp lane, for example,

'off-ramp lane ends soon' is outputted.

Also, in the off-ramp lane guidance, a remaining distance from the current location to the end point may be repeatedly provided at every predetermined distance before reaching the end point of the off-ramp lane after passing the start point, for example, '500 m of off-ramp lane is remaining'.

Referring again to FIG. 5, in operation S50, it is determined whether a user has deviated from the route shortly after passing the end point of the off-ramp lane. That is, a route where the user moves is traced after providing guidance about the intersection, and when it is determined that the user has deviated from the route, the route to the destination is re-retrieved and provided.

Accordingly, the intersection guidance method of the navigation system provides guidance about the access to the intersection before the off-ramp lane of the intersection, and guidance about the off-ramp lane in the area to the off-ramp lane.

Also, it is checked whether the user has deviated from the route shortly after passing the off-ramp lane, and thus the route may be re-retrieved quickly.

The above-described embodiment of the present invention may be recorded in computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The media and program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVD; magneto-optical media such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments of the present invention. According to an embodiment of the present invention, an intersection guidance apparatus and method of a navigation system separately provides guidance about an access to an intersection and area to an off-ramp based on an off-ramp lane of the intersection when providing guidance about the intersection, and thereby may provide guidance about the intersection more accurately. Also, according to an embodiment of the present invention, an intersection guidance apparatus and method of a navigation system retrieves a route again at a point where an off-ramp lane ends when a user has deviated from the route, and thereby may overcome a route re-retrieval error and provide guidance about more accurate route to the driving user.

Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An intersection guidance method of a navigation system, the intersection guidance method comprising: retrieving a route to a destination set by a user and providing guidance about the retrieved route; and providing, when an intersection on the route is sensed, guidance information about the intersection based on a predetermined off-ramp lane with respect to the intersection.

2. The intersection guidance method of claim 1, wherein the off-ramp lane is defined as a coordinate value of a start point and end point of an area to an off-ramp included in the intersection.

3. The intersection guidance method of claim 2, wherein the providing guidance about the intersection comprises: outputting guidance information at predetermined intervals before entering the off-ramp lane of the intersection, the guidance information notifying about an access to the intersection; and outputting, when entering the off-ramp lane, guidance information at predetermined intervals from a start point to an end point of the off-ramp lane, the guidance information notifying about the off-ramp lane.

4. The intersection guidance method of claim 3, wherein the outputting of the guidance information notifying about the access to the intersection comprises: sensing the intersection located a predetermined distance ahead from a current location; and outputting the guidance information notifying about the access to the intersection shortly before reaching the start point of the off-ramp lane from a point where the intersection is sensed.

5. The intersection guidance method of claim 4, wherein the outputting of the guidance information notifying about the access to the intersection comprises outputting guidance information at least once, the guidance information notifying about the sensing of the intersection and a remaining distance to the intersection.

6. The intersection guidance method of claim 3, wherein the outputting of the guidance information notifying about the off-ramp lane comprises: determining whether a current location is approaching the start point of the off- ramp lane; and outputting the guidance information notifying about the off-ramp lane from the start point to the end point of the off-ramp lane when the user reaches the start point of the off-ramp lane.

7. The intersection guidance method of claim 6, wherein the outputting of the guidance information notifying about the off-ramp lane comprises: outputting guidance information notifying the current location is the start point of the off-ramp lane; and outputting guidance information notifying the current location is the end point of the off-ramp lane.

8. The intersection guidance method of claim 7, wherein the outputting of the guidance information notifying about the off-ramp lane further comprises outputting guidance information notifying about a remaining distance to the end point of the off- ramp lane at least once, before outputting the guidance information notifying about the end point of the off-ramp lane.

9. The intersection guidance method of claim 3, wherein the providing of the guidance information about the intersection further comprises determining whether the user has deviated from the route shortly after passing the end point of the off-ramp lane.

10. A computer-readable recording medium storing a program for implementing the method according to any one of claims 1 through 9.

11. An intersection guidance apparatus of a navigation system, the intersection guidance apparatus comprising: a map database storing an off-ramp lane for each intersection, the off-ramp lane indicating an area to an off-ramp, and the intersection including at least one off-ramp; and a control unit, when the intersection on a route to a destination set by the user is sensed, providing guidance information about a corresponding intersection based on the off-ramp lane stored in the map database.

12. The intersection guidance apparatus of claim 11, wherein the map database establishes and stores a coordinate value corresponding to a start point and end point of the off-ramp lane for each intersection.

13. The intersection guidance apparatus of claim 11 , wherein, when the intersection is sensed, the control unit controls guidance information notifying about an access to the intersection to be outputted before the off-ramp lane, and controls guidance information notifying about the off-ramp lane to be outputted within the off-ramp lane.

14. The intersection guidance apparatus of claim 11, further comprising: a route calculation unit re-searching the route to the destination shortly after passing the off-ramp lane of the intersection under a control of the control unit.