This application is based on and claims the benefit of priority of Japanese Patent Applications No. 2005-315747 filed on Oct. 31, 2005, the disclosure of which is incorporated herein by reference.
The present invention generally relates to a navigation system for use in a vehicle.
In recent years, a specific type of navigation system is used to navigate a vehicle that is traveling in a roundabout, or a traffic circle, in addition to providing route navigation toward a predetermined destination of a travel. The vehicle in or around the traffic circle is provided by the navigation system an exiting road from the traffic circle. For example, Japanese patent application No. JP-A-H11-72343 discloses a navigation system that notifies a user of the number of exiting roads from the traffic circle. Also, it is known to the public that a specific type of navigation system notifies the user of a relative angle of a exiting road against an entrance road based on an angle of the entrance road and an angle of the exiting road to and from the traffic circle.
However, the number of the exiting roads of the traffic circle and/or the direction of the exiting road relative to the entrance road do not provide for a driver of the vehicle a clue how far the exiting road really is. That is, the driver is left ill-informed about the remaining time for reaching the exiting road even when he/she is using the navigation system.
In view of the above-described and other problems, the present disclosure provides a navigation system that provides for a driver of the vehicle a concrete idea about how soon the vehicle reaches an exiting road from the traffic circle when the vehicle is traveling in or toward the traffic circle.
In one aspect of the present disclosure, the navigation system for navigating a vehicle toward a destination of a travel based on a detected current position includes an position detector for detecting a current position of the vehicle, and an information provision unit for providing navigation information for a user. The position detector detects a distance between the vehicle and a traffic circle, and, based on the current position of the vehicle detected by the position detector, the information provision unit provides for the user the navigation information that includes a size of the traffic circle when the distance between the vehicle and the traffic circle becomes equal to or smaller than a predetermined value. In this manner, the user, or the driver of the vehicle, can have an idea how big the size of the traffic circle is. In addition, the navigation system provides the navigation information about an exiting road from the traffic circle. In this manner, the user can have an idea how soon the vehicle reaches a proper road that exits from the traffic circle onto a route toward the destination of the travel.
In another aspect of the present disclosure, the navigation system provides for the user the number of the branching roads before the user arrives at the exiting road. The navigation system also provides a circumferential travel distance of the traffic circle, and/or a diameter or the traffic circle for the user. In this manner, the user can have an idea that how soon the vehicle reaches a proper road that exits from the traffic circle onto a route toward the destination of the travel.
In yet another aspect of the present disclosure, the navigation system provides an illustrative graphic that represents the size of the traffic circle on a display unit, and/or provides a guidance voice that notifies the size of the traffic circle. In this manner, the user can have an idea that how soon the vehicle reaches a proper road that exits from the traffic circle onto a route toward the destination of the travel.
In yet another aspect of the present disclosure, the navigation system provides the size of the traffic circle for the user based on map data that includes link data and node data. That is, the navigation system calculates the size of the traffic circle by summing the distance of each link included in the traffic circle. In this manner, the size of the traffic circle can be provided for the user based on a conventional map data. In addition, when the map data includes the size of the traffic circles as additional attributes, the navigation system provides the size of the traffic circle by utilizing the size of the traffic circle included in the map data. In this manner, the calculation operation of the traffic circle size is eliminated.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:
Embodiments of the present disclosure are described with reference to the drawings. The embodiments of the present disclosure are not necessarily limited to the types/forms in the present embodiment, but may take any form of the art or technique that is regarded within the scope of the present disclosure by artisans who have ordinary skills in the art.
The control unit 8 is a well-known type of computer that includes a CPU, a ROM, a RAM, an I/O and a bus line for connecting those components. The ROM stores a program that is executed by the control unit 8. The program controls processes and calculations conducted by the CPU.
The position detector 1 includes a plurality of well-known type sensors such as a geomagnetism sensor 2, a gyroscope 3, a distance sensor 4, and a Global Positioning System (GPS) receiver 5. The geomagnetism sensor 2 is used to detect a magnetic direction of a vehicle, and the gyroscope 3 is used to detect a relative bearing of the vehicle. The distance sensor 4 is used to detect a travel distance of the vehicle, and the GPS receiver 5 receives a radio wave from a GPS satellite for detecting a position of the vehicle. These sensors and/or receivers can compensate respectively different characteristics of inherent errors by interacting complementarily with each other. These sensors and/or receivers may selectively be used based on the accuracy of the output, and a steering rotation sensor, a speed sensor or the like (not shown in the figure) may additionally be utilized for compensation of the accuracy.
The map data input unit 6 is used to input digital map data such as road data, background drawing data, text data, facility data and the like. These data are provided by a memory medium such as a DVD-ROM, a CD-ROM (not shown in the figure). The map data input unit 6 retrieves these data from the DVD-ROM drive, the CD-ROM drive or the like connected thereto, and inputs them to the control unit 8. The map data in the memory medium includes links and nodes as road network data.
The operation switches 7 in
The remote controller 17 has a plurality of switches (not shown in the figure) for inputting the same kind of instructions as the instructions from the operation switches 7. The remote controller 17 outputs control signals of instructions, and the control signals are provided for the control unit 8 through the remote sensor 16.
The external memory 9 is a memory medium, e.g., a memory card, a hard disk or the like, with read/write capability for storing data and/or information such as text data, image data, sound data as well as user information, e.g., a location of user's home and the like.
The display unit 10 is, for example, a liquid crystal display, an organic EL display or the like. The display unit 10 displays a position mark 20 (refer to the illustration in
The transceiver 11 is a communication device for providing communication with external information sources for the control unit 8. For example, traffic information, weather information, date information, facility information and advertisement information are received from external information resources by using the transceiver 11. The information may be outputted from the transceiver 11 after processing in the control unit 8.
The speaker 13 is used to output a predetermined sequence of sound such as navigation guidance voice, screen operation guidance voice, voice recognition result or the like based on a sound output signal from the voice controller 12.
The microphone 15 converts user's voice to an electric signal that is inputted to the voice recognizer 14. The voice recognizer 14 recognizes the inputted user's voice for pattern comparison with vocabulary data in an internal recognition dictionary (not shown in the figure), and outputs most resembling vocabulary data to the user's voice as a recognition result to the voice controller 12.
The voice controller 12 controls the voice recognizer 14, and gives response to the user by providing talk back voice from the speaker 13. The voice controller 12 also controls the input of the recognition result of the voice recognizer 14 to the control unit 8.
The control unit 8 executes a predetermined process in response to the user's voice based on the recognition result of the voice recognizer 14, or in response to the user input from the operation switches 7 or from the remote controller 17. The predetermine process includes, for example, a map data storage process for storing the map data in the external memory 9, a map scale change process, a menu selection process, a destination setting process, a route search execution process, a route navigation start process, a current position correction process, a display screen change process, a volume control process and the like. Further, route navigation guidance information or the like processed in the control unit 8 is provided for the user from the speaker 13 in a suitable manner under control of the voice controller 12.
The process starts with step S10. In step S10, the process determines a current vehicle position based on a signal from the position detector 1.
In step S20, the process determines whether the vehicle is approaching to the traffic circle. That is, the process determines whether the current vehicle position is within a predetermined distance from the traffic circle. The predetermined distance may be a few dozens of meters or the like. The process examines the proximity to the traffic circle by referring to the traffic circle information of the link data that belongs to the link in a predetermined distance ahead of the vehicle. The process concludes itself when the vehicle is not approaching to the traffic circle (step S20:NO). The process proceeds to step S30 when the vehicle is approaching to the traffic circle (step S20:YES).
In step S30, the process calculates a diameter of the traffic circle by using the link data.
A total circumferential distance Ci of the traffic circle in
R=Ci/π [Equation 1]
Now, in step S40, the process draws an traffic circle illustration 24 having an entering route and an exiting route based on a navigation route and the map data.
In step S50, as shown in
In step S60, the process provides a guidance voice for the user from the speaker 13. The guidance voice for notifying the user of a size of the traffic circle and a direction of the exit relative to the entrance may sound “The vehicle is approaching to a traffic circle. Exit from the traffic circle having a diameter of 50 meters.”
The navigation system of the present disclosure provides a size of the traffic circle and an exiting direction from the traffic circle relative to an entering direction of the traffic circle, thereby enabling the user to easily recognizing how far and/or how soon the vehicle reaches an exit point. Further, the size of the traffic circle provides for the user an idea that how the user may maneuver the vehicle in the traffic circle.
Although the present disclosure has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.
For example, the size of the traffic circle may be provided as a circumferential distance of the traffic circle instead of the diameter of the traffic circle, or may be provided as a radius of the traffic circle.
Further, the diameter of the traffic circle may be stored and retrieved as diameter information from a memory in the map data input unit 6 instead of calculating it by summing the link length in the links in the traffic circle when the vehicle approaches the traffic circle.
Furthermore, the number of exit points or exit routes between the entering point and the exit point in the traffic circle may be notified to the user in addition to, or instead of, the exit direction relative to the entering direction. That is, as shown in
Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.
Number | Date | Country | Kind |
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2005-315747 | Oct 2005 | JP | national |