JP2006071539A - Car navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To present a driver with the instruction that it is the road to travel for the first time and the information on the road, in the case where the road after the turning is the road to travel for the first time, at the time when approaching the turning point, in the process for performing the route guidance. <P>SOLUTION: There are provided: an own-vehicle position detection means for detecting the position of the vehicle of one's own; a route search means for searching for the travel route to the destination; a route guidance means for performing the travel guidance according to the searched travel route; and a passed road storage means for storing the road section traveled in the past. When the road section to travel after the turning is the road section not stored in the passed road storage means, the driver is notified of the road section to travel for the first time and the road information on the road section, at the time when approaching the turning point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a car navigation device, and in particular, when performing route guidance according to a searched route, if the road after the change of route is a road that has never passed in the past, that fact and the road about the road The present invention relates to a car navigation device having a function of notifying a driver of information in advance and calling attention.

  The basic functions of the car navigation system are a locator function that detects the current position of the vehicle, displays it on the map and informs the driver, a navigator function that searches the optimum route to the destination, and provides route guidance, VICS (Vehicle Information & It is said that it has a real-time traffic information collection function that receives road traffic information provided by the Communication System) and various service information such as sightseeing spots and restaurants and provides them to the driver.

In the navigator function, the optimum route is searched in response to instructions from the departure point and the destination in advance. While traveling, the searched route is displayed on the map screen together with the target and the vehicle position detected by the locator function is always displayed on the route while being updated. Then, when approaching the turning point on the planned route, the driver is informed in advance of the course direction to be taken.
Instructions for changing the course in advance when approaching the planned turning point are generally displayed on the screen of a mark indicating an intersection or a branch point and a traveling direction arrow, and "After XX meters, it is an intersection. "Turn right." This is done by informing the turning point and the direction of the route by a voice message such as. By following the instructions, the driver can reach the destination through the optimum route without making a mistake on the road.

However, if the road that runs after the turn is the first road that has never passed before, the road situation may not be known. In that case, the driver may feel confused or uneasy about driving.
JP-A-53-38034 JP-A-7-160996

  The present invention has been made from such a background, and the problem is that in the process of navigating the route to the destination by the navigator function, if the road after the turn is the first road to pass, An object of the present invention is to provide a car navigation device having a function of notifying a driver of information on the road and the road.

  The invention according to claim 1 for solving the above-described problem is a vehicle position detection means for detecting the position of the vehicle, a route search means for searching for a travel route to the destination, and a driver according to the searched travel route. A car navigation device having route guidance means for guiding the vehicle, further comprising passing road storage means for storing a road section that has passed in the past, wherein the route guidance means includes a road section that passes after the turn. In the case of a road section that is not stored in the passing road storage means, a car navigation system that notifies the driver that the road section after the turn is the first road section when the turn point is approached. Device.

  According to the car navigation device having such a configuration, that fact is notified in advance before entering a road that has not passed in the past. As a result, the driver can enter with increased attention, and thus safer driving is possible.

  Further, the invention according to claim 2 is the car navigation device according to claim 1, further comprising a road information database for storing road information for each road section, wherein the route guidance means is the road through which the road passes for the first time. When notifying that it is a section, road information about the road section is read from the road information database and notified together.

  According to such a configuration, road information about a road section that passes for the first time is notified in advance. As a result, the driver can perform driving considering the road information from the beginning, and thus safer driving is possible.

  The invention according to claim 3 is the car navigation device according to claim 2, wherein the road information to be notified includes at least one of the number of lanes, the speed limit, and the road type. It is characterized by that.

  The number of lanes, speed limit, road type, and the like for the first road section are information that the driver wants to know most about safe driving. Therefore, if this information is notified in advance, the driver can perform driving in consideration of these points from the beginning, and thus safer driving is possible.

  Hereinafter, an embodiment of a car navigation device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a car navigation apparatus according to the present invention. The car navigation device 1 includes a control circuit 2, a GPS receiver 3, a vehicle body direction sensor 4, a vehicle speed sensor 5, a distance sensor 6, an operation switch group 7, a communication device 8, a display device 9, an audio output device 10, a magnetic disk device ( (Hereinafter referred to as HDD) 11.

The control circuit 2 has a function of controlling the overall operation of the car navigation device 1 and is mainly composed of a microcomputer. Inside the CPU 14, a RAM 15, a ROM 16, a bus (not shown) for connecting them, an I / O Interface, power supply, etc. are provided.
The GPS receiver 3 receives signals from a plurality of GPS artificial satellites and transmits them to the control circuit 2. Based on the information, necessary arithmetic processing is performed in the control circuit 2 to calculate the current position of the vehicle. Is done. The vehicle body direction sensor 4 is a sensor configured by a geomagnetic sensor, a vibration gyro, or the like, and detects the direction of the vehicle body. The vehicle speed sensor 5 is for detecting the vehicle speed. For example, the vehicle speed is detected by converting the rotation of the transmission into an electric signal. The distance sensor 6 is a sensor that measures the travel distance, and measures the travel distance by counting the number of rotations of the front wheel, for example.

  The operation switch group 7 is used for inputting commands and data to the control circuit 2 and includes, for example, a touch switch, a remote control switch, a voice input device, and the like formed on a color liquid crystal display. The communication device 8 is for receiving road traffic information from a VICS (Vehicle Information & Communication System), exchanging information by connecting to a mobile phone network or the Internet. The display device 9 is for displaying a road map, a current position of the vehicle, a travel route, road information to be described later, and the like, and is constituted by a color liquid crystal display, for example. The voice output device 10 is used to transmit the output information from the control circuit 2 to the driver instead of the artificial voice, and is also used to transmit road information described later.

  In the HDD 11, a map database indispensable for exhibiting the navigator function and various programs for operating the car navigation device 1 are stored in advance. This program includes a program for executing a general navigator function in addition to a program for exhibiting a function specific to the present invention described later, for example, a function for calculating a current position based on a signal from the GPS receiver 3 A map matching processing function that positions the calculated current position on the map, a route search function that searches for a route from the current position to the destination in response to designation of the destination or waypoint, and a travel route according to the route search result A program for executing a route guidance function for displaying and guiding on a map screen, a function for receiving road traffic information from VICS and notifying the driver, and the like are included.

  In addition to the devices as described above, the car navigation device 1 is equipped with an acceleration sensor for detecting acceleration in the vertical / front / rear / left / right directions of the vehicle, a vehicle body inclination angle sensor for detecting the vehicle body inclination angle, and the like as necessary.

  The car navigation device 1 according to the present invention is a road that passes after the next course change (after the next turn) in the process in which the route guidance means travels and guides the driver to the destination according to the travel route searched by the route search means. If the section is a road section that has not passed in the past, it is characterized in that the fact and the road information about the road section are added to the conventional route guidance information to inform the driver.

  In order for the route guidance means to provide travel guidance including provision of additional information as described above, it is necessary to determine a travel route from the current point to the designated destination as a premise. The travel route is determined by the route search means based on the departure point, waypoint, and destination designated by the driver (user). In addition, when performing actual travel guidance, it is essential to detect the vehicle position. The own vehicle position is detected by the own vehicle position detecting means. The method of route search by the route search means and the method of vehicle position detection by the vehicle position detection means in the present invention are both the same as the method adopted in the conventional car navigation apparatus. First, I will briefly explain them.

  In the present embodiment, the vehicle position detection means includes a GPS receiver 3, a control circuit 2, a map database, and a program executed on the control circuit 2 to calculate the vehicle position. The GPS receiver 3 receives radio waves emitted in synchronization with an accurate clock from an artificial satellite arranged for GPS, and measures the propagation time taken for the emitted radio waves to reach the GPS receiver 3 To do. When the propagation time is known, the distance to the satellite that emitted the radio wave is obtained. The position of the satellite can be calculated based on the orbit data sent simultaneously. If the distances to a plurality of satellites are measured at the same time, the position of the GPS receiver 3, that is, the vehicle position can be calculated from the obtained distance. In principle, the vehicle position can be calculated by simultaneously measuring the distance to three satellites. However, since it is difficult to accurately set the GPS receiver 3 clock for propagation time measurement to the satellite clock, the GPS receiver 3 clock error is also unknown and the radio waves from the four satellites are received. Each distance is measured. The calculation is performed in the GPS receiver 3 or the control circuit 2.

  The vehicle position detected in this way includes an error. Accordingly, the control circuit 2 performs map matching processing for correcting the vehicle position on the premise that the vehicle is traveling on the road and positioning the vehicle on the road of the map read from the map database. This process positions the vehicle on the nearest road on the map. Thus, the position (coordinates) of the own vehicle is determined. When the position of the host vehicle is determined, the measured values of the vehicle body direction sensor 4, the vehicle speed sensor 5, and the distance sensor 6 are used for position correction.

  In this embodiment, the route search means is configured by the control circuit 2, the map database, the operation switch group 7, the display device 9, and a program executed on the control circuit 2 for route search. The waypoint and destination are input using the operation switch group 7. The current position is obtained by the vehicle position detection means described above. The control circuit 2 searches for the optimum route to the destination using the Dijkstra method or a search method according to the information and the road data in the map database.

  Road data used for route search is defined by defining intersections, turning points, dead ends, etc. of each road as nodes and roads between the nodes as links (corresponding to road sections) and connecting the links. It is a map. In each link, attributes such as connection information with previous and subsequent links and road information of each link are stored as link information. In the Dijkstra method, a route cost is calculated using link information and connection information, and a route to a destination is set by connecting links that minimize the calculated route cost.

  The route to the destination is usually searched for several types under different conditions, and the result is displayed on the display device 9. The driving route to the destination is determined by the driver selecting the desired route. The determined travel route is represented as a sequence of link numbers and node numbers of roads that pass from the current location to the destination.

  Next, an embodiment of the characteristic function of the car navigation device 1 according to the present invention will be described. In the car navigation device 1 of the present invention, when the link (road section) after the next course change is the first passing link that has not passed in the past, the driver is notified before entering the link. To do.

  For this purpose, it is necessary to store in the database the links that have been passed in the past. The storage is performed by the passing road storage means. When traveling by the travel guidance by the route guidance means, the route guidance means grasps the link on which the host vehicle is currently traveling. Accordingly, the passing road storage means obtains an ID (index) for specifying the traveling link from the route guidance means and registers it in the database. In that case, only an unregistered link ID is additionally registered without re-registering an already registered ID. By doing so, a database is created that stores the IDs of links that have passed in the past.

Next, on the premise that such a database has been created, it is checked whether or not the link after the change of course is the first link to pass, and if it is the first link, that fact and the link A control flow for providing road information will be described with reference to the flowchart of FIG. FIG. 2 is a flow performed by the route guidance means.
In the first step S1, travel route information to the destination is acquired. This is information on the travel route searched by the route search means described above and selected by the driver. The travel route information is a table in which a link ID scheduled to pass and a node ID are connected.

  In the subsequent step S2, the vehicle position information detected by the vehicle position detection means described above is acquired. If the vehicle position is known, the running link is determined, and the next course change point (turning point) is read in light of the travel route information to the destination (step S3). If the course change point is found, in the subsequent step S4, it is checked whether or not the point where the driver is informed of the course change guidance for the course change point has been reached. The route change guidance is given when a certain distance is reached before the route change point. The coordinates of the node corresponding to the route change point are stored as road data in the map database as node information. The coordinates of the vehicle are known by the vehicle position detection means. Therefore, it can be determined whether or not the vehicle has reached the point where the route change guidance is provided from the coordinates of both.

  If it is determined in step S4 that the route change guidance point has been reached, the process proceeds to step S5 to notify the driver of the conventional route change guide. This conventional guidance is displayed on the display device 9 with a mark indicating an intersection or a branching point and a traveling direction arrow, and voice output such as “It is an intersection at XX meters. Turn right at the intersection.” This is performed by voice message from the device 10. The contents of the conventional route change guidance are generally only a route change point (turning point) and a route direction.

  The following steps S6 to S8 are features of the car navigation device 1 of the present invention. In step S6, it is checked whether or not the link that passes after the next course change is a link that has passed in the past. As described above, the link ID of a link that has been passed in the past is stored in the database by the passing road storage means. Therefore, by checking whether or not the link ID after the course change is stored in the database, it can be determined whether or not the link after the course change is the first link.

  If the link has passed in the past, the process proceeds to step S9. If the link passes for the first time, the process proceeds to step S7. Then, the driver is alerted by displaying on the display device 9 that the road after the change of course is the first road to be passed and a voice message from the voice output device 10.

  In the subsequent step S8, road information about the first road is read and notified to the driver. The road information for each link is stored in the map database as a part of the link information in association with the link ID (corresponding to the road information database). The road information includes link length, link direction (road direction), road type, road width, number of lanes, presence / absence of sidewalk, toll, weight limit / vehicle width limit / vehicle length limit / vehicle height limit / vehicle speed limit. Various traffic regulation information such as (restricted speed) / restricted vehicle type / one-way traffic / prohibited entry / restricted traffic time zone are recorded. As the road information, traffic regulation information, the number of lanes, the road type, etc. that are considered important for safe driving are picked up and notified to the driver. The notification is performed by display on the display device 9 and a voice message by the voice output device 10.

  In step S9, it is checked whether or not the guided route change has been completed. Whether or not the course has been changed can be determined by determining a running link based on the vehicle position detected by the vehicle position detection means. If the course change is completed, the process returns to step S3 to move to the next course change guide.

  As described above, in the car navigation device 1 of the present invention, the links that have been passed are stored as a database, and whether or not the road after the next route change is the first passage during the travel guidance is stored in the database. Refer to and judge. If the road passes for the first time, the driver is notified of that fact and road information about the road. Therefore, since the driver can drive while paying attention to the information that is notified in advance, there is an effect that safer driving is possible than when the information is not notified in advance.

  The route guidance means described in the claims comprises the control circuit 2, the display device 9, the audio output device 10, the map database, the vehicle position detection means, and the route guidance program. The passing road storage means includes a control circuit 2, HDD 11, a map database, the vehicle position detection means, and a program for storing the passing link in the database.

1 is a block diagram showing an overall configuration of a car navigation device according to the present invention. It is a processing flow of route guidance performed by route guidance means.

Explanation of symbols

  In the drawings, 1 is a car navigation device, 2 is a control circuit, 3 is a GPS receiver, 7 is an operation switch group, 8 is a communication device, 9 is a display device, 10 is an audio output device, and 22 is an HDD.

Claims (3)

A car navigation device comprising own vehicle position detecting means for detecting the own vehicle position, route searching means for searching for a travel route to a destination, and route guidance means for guiding a driver according to the searched travel route,
Passage road storage means for storing road sections that have passed in the past is further provided, and the route guidance means is configured such that the road section that passes after the turn is a road section that is not stored in the passage road storage means. A car navigation device characterized in that, when approaching the turning point, the driver is notified that the road section after the turn is the first road section to pass.   The car navigation device according to claim 1, further comprising a road information database that stores road information about each road section, wherein the route guidance means informs that the road section passes for the first time, A car navigation device characterized in that road information about a road section is read from the road information database and notified at the same time. 3. The car navigation device according to claim 2, wherein the road information to be notified includes any one or more of a number of lanes, a speed limit, and a road type.

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