JP2007040761A - Navigation system, terminal, and map display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the visualization of map display including a present position when an error in matching processing for correcting a positioning error for the present position exceeds tolerance during operations in a three-dimensional display mode. <P>SOLUTION: The navigation system 10 displays a map, guide routes, and the present position positioned by a positioning means on a display means 221 and comprises a matching processing means 214 which has a first display mode for providing display by two-dimensional image display and a second display mode for providing display by three-dimensional image display and performs matching on a road or a guide route when the positioning error for the present position positioned by positioning means 212, 213 is within predetermined tolerance and an error detection means 220 for deciding whether the positioning error is within the predetermined tolerance or not. When the error detection means 220 detects that the positioning error is not within the predetermined tolerance in the second display mode, the display is altered to the first display mode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a navigation system, a terminal device, and a map display method for searching and guiding an optimum route from a departure place to a destination for pedestrians and automobile drivers. The present invention particularly relates to a three-dimensional display in a navigation system, a route search server, a terminal device, and a map display method having a display mode for two-dimensionally displaying a route, a map, and a building, and a display mode for displaying three-dimensionally. The present invention relates to a navigation system, a terminal device, and a map display method that are switched to a two-dimensional display mode when an error in a matching process for correcting a positioning error of a current position during operation in a mode exceeds an allowable range.

  Conventionally, when visiting a destination place on an unknown land, the user arrives while checking the transportation, road, landmark and address drawn on the map by using a map book or the like. In a car equipped with a car navigation system (hereinafter simply referred to as a car navigation system), a guidance displayed on a monitor screen or a voice output guidance (navigation) by starting the car navigation system and inputting a destination. Information) was reached.

  The car navigation system uses a GPS (Global Positioning System), receives GPS signals transmitted from a plurality of GPS satellites orbiting the earth with a GPS antenna, and transmits the GPS signals to the GPS signals. The position is specified by analyzing the satellite position and clock information included. At least four GPS satellites are required. The single positioning accuracy of GPS is generally over 10 m, but it is improved to 5 m or less by adopting DGPS (Differential GPS). In particular, positioning units that are currently installed only on some mobile phones, such as GPS receivers that receive and measure signals from GPS (Global Positioning System) satellites, are called the third generation. Mobile phones tend to be installed in all models.

  Various technologies have been proposed for using mobile terminals having such a positioning function. For example, a navigation device (car navigation) for automobiles has been developed, and map / route information is obtained using a mobile phone as a terminal. A communication navigation system for pedestrians distributed from an information distribution server (route search server) has been proposed.

  In recent years, the performance of mobile communication terminal devices such as mobile phones and PHS has been dramatically improved, and multi-functionalization has been progressing. In particular, the data communication function is strengthened in addition to the call function, and various data communication services are provided to the user via the Internet. A navigation service is one of them, and a communication navigation system that provides route guidance from a current position to a destination for not only a driver of a car but also a mobile phone user has been put into practical use.

  A general navigation device, a route search device and a route search method used in a communication navigation system are disclosed in, for example, the following Patent Document 1 (Japanese Patent Laid-Open No. 2001-165681). This navigation system is configured to send information on a departure point and a destination from a portable navigation terminal to an information distribution server, and the information distribution server searches and guides a route that matches a search condition from road network and traffic network data. Has been. As the search condition, there are means for moving from the departure place to the destination, for example, walking, automobile, combined use of railroad and walking, and the route is searched as one of the search conditions.

  The information distribution server has roads (routes) of map data as nodes and nodes as the positions of inflection points, links connecting the nodes as links, and cost information (distance and required time) of all links as a database. ing. Then, the information distribution server sequentially searches for a link from the departure node to the destination node with reference to the database, and traces the node and link with the smallest cost information of the link as a guide route. The shortest route can be guided to the portable navigation terminal. As such a route search method, a method called label determination method or Dijkstra method is used. Patent Document 1 also discloses a route search method using this Dijkstra method.

  By the way, a terminal device that has received a guidance route from an information distribution server such as a route search server is provided with a display means such as a liquid crystal display device, and displays a map and a guidance route on the display means as well as the current state of pedestrians and cars. The position (current position of the terminal device) is displayed on the guidance route to guide pedestrians and cars to the destination. Generally, the map displayed on the display means is a plan view, that is, a display of a two-dimensional figure. However, in order to make it easy to see the state of the plane bird's-eye view, landmarks, and buildings with a perspective on the display image, the building 3 A method of displaying a bird's eye view expressed in a three-dimensional manner, that is, a three-dimensional figure, has also been proposed.

  For example, the following Patent Document 2 (Japanese Patent Laid-Open No. 2001-27534) discloses a map display device that draws a state of a building wall and displays it three-dimensionally. The map display device disclosed in Patent Document 2 is intended to facilitate identification of a building and easy correspondence with an actual landscape in a map display device used in a vehicle navigation device. A building that is displayed three-dimensionally is drawn by setting a window frame shape and wall color according to the type of building. At that time, the number of steps of the window frame is the same as the number of floors of the actual building, and the destination building is colored dark red on the roof. That is, this map display device is a map display device that three-dimensionally displays roads, buildings, etc. on the display means based on the map data stored in the map data storage means, wherein the building is displayed on the display means, It is displayed with a modification according to the characteristics of the building.

In order to perform the display as described above, in the map display device disclosed in Patent Document 2, the map data storage device includes a large-capacity storage medium such as a DVD-ROM, a hard disk, and a CD-ROM as a storage medium, and this storage. And a reproducing apparatus for reproducing data stored in the medium. The storage medium includes 3D digital data including road map data and 3D data such as various buildings (government offices, banks, schools, station buildings, airports, hotels, buildings, various facilities, etc.). (Road) Map database is recorded.

  In addition, text information for displaying names of intersections, cities, villages, towns, etc. is recorded on the recording medium. Data for three-dimensionally displaying a building in the road map data includes position data, polygon data describing the planar shape and height (floor) data of the building, and the like. The recording medium also stores type data representing the type of building and text information for displaying the name of the building in characters.

  If a building is displayed three-dimensionally as well as a map and a route, the road and route are hidden by the figure of the building. For this reason, intersections that should turn left and right are behind the building, making it difficult to see. In order to eliminate such inconvenience, for example, the following Patent Document 3 (Japanese Patent Laid-Open No. 2000-112343) has a technique of “stereoscopic display method for navigation” that makes a three-dimensional display of a building in front of an intersection transparent. It is disclosed.

  In the three-dimensional display method for navigation disclosed in Patent Document 3, when a building is displayed in three dimensions, it is determined whether or not there is an intersection scheduled to turn left or right on the map on the screen. It is determined whether or not there is a three-dimensionally displayed building in front of the intersection on the side to bend. In some cases, the building is stereoscopically displayed in a frame, and the inside of the building is transparently colored such as transparent red, and the other buildings are distinguished by performing normal stereoscopic display or simple wire frame display. This avoids the inconvenience that roads and routes are hidden by the figure of the building.

  Further, a map display device that has a two-dimensional display mode and a three-dimensional display mode and is configured so that a user can select one of the display modes or automatically switch according to a predetermined condition is also disclosed in, for example, the following patents: It is disclosed in Document 4 (Japanese Patent Application Laid-Open No. 2004-151752) and Patent Document 5 (Japanese Patent Application Laid-Open No. 11-24556).

  The electronic map display device disclosed in Patent Document 4 includes a map information storage unit that stores map information in a plurality of display formats, a display unit, and a display screen of the display unit or an inclination angle of the electronic map display device. And a control unit configured to read out and display map information of a corresponding display format from the map information storage unit based on the detected tilt angle.

  In addition, the map display device disclosed in Patent Document 5 takes into account the height of a plurality of points in the plane map, the bird's-eye view map obtained by converting the plane map into a display format based on the bird's-eye view, and the ground surface of the bird's-eye view map. In a map display device that selectively displays a three-dimensional bird's-eye view map and a house map, (a) when a planar map is displayed, the display is switched to either the bird's-eye view map or the house map, (B) When the bird's-eye view map is displayed, the display is switched to either the stereoscopic bird's-eye view map or the planar map. (C) When the stereoscopic bird's-eye view map is displayed, either the bird's-eye view map or the planar map is displayed. The display is switched, and (d) when the house map is displayed, the display is switched to the plane map.

  On the other hand, in a navigation system, the current position is measured by positioning means such as a GPS receiver, and a current position mark indicating the current position and a direction mark indicating the traveling direction are superimposed when displaying a map or a guide route. Display and inform the user of the current position and direction of travel. In addition, guidance points such as intersections are set in the guide route data, and voice guidance data (for example, a voice message such as “This is a 300m intersection, please turn left”) is added as guidance at the guidance points. In this case, a voice message is reproduced and output through a speaker to guide the user.

  In general, in a navigation system as described above, a navigation terminal device is equipped with a GPS receiver as positioning means. This positioning means receives and processes GPS satellite signals transmitted by a plurality of GPS satellite signals, and measures the current position (latitude / longitude). This method is called satellite navigation. GPS satellite signals cannot be received in tunnels or underground, and GPS signals are reflected in places where buildings are densely packed, resulting in poor positioning accuracy.

  For this reason, in-vehicle navigation devices and the like are provided with positioning means for positioning the current position by providing an acceleration sensor, a steering angle sensor, a gyroscope, a vehicle speed sensor, and the like. This positioning method is called each autonomous navigation. Recently, there have also appeared devices for a pedestrian navigation terminal device using a mobile phone as a navigation terminal device, which are equipped with an attitude detection sensor and a gyro and combined with a positioning function based on autonomous navigation.

  It is well known that the current position by the positioning means using the GPS receiver includes a calculation error in the processing of the GPS satellite signal. In general, the single positioning accuracy of GPS is generally over 10 m, and the position (latitude / longitude) measured by the GPS positioning means may deviate from the road. The matching process is a process for correcting a deviation from the road due to this error. Normally, it is a process that extracts the road closest to the current position (positioned latitude / longitude), and draws a perpendicular to the road from the current position, and corrects the intersection with the road as the current position (corrected latitude / longitude). . Such a processing method is called a projection method. A method of performing the above processing using road data on a map is called map matching, and a method of performing the above processing using route data searched by the route search server is called route matching.

  In addition, the position information measured by the autonomous navigation means measures the current position by accumulating the movement distance and direction change measured by various sensors from the own vehicle position measured last time, and the positioning error is accumulated. go. In this case, matching processing is also required. In general, positioning by satellite navigation using GPS can determine the absolute position of the vehicle, so positioning results by satellite navigation are used in places where the sky is open and GPS satellite signals are well received.

  By performing the matching process and correcting the positioning error of the vehicle position, when displaying the vehicle position on the map, it can be displayed correctly on the road that is the guide route, and the user can Driving can be continued while confirming that the vehicle is traveling on a road that is a guide route.

JP 2001-165681 A (FIGS. 1 and 2) JP-A-2001-27534 (FIGS. 1 and 6, paragraphs [0015] and [0037] to [0045]) JP 2000-112343 A (FIGS. 14 and 15) Japanese Patent Laying-Open No. 2004-151752 (FIG. 4) Japanese Patent Laid-Open No. 11-24556 (FIG. 23)

  When the map display is two-dimensionally displayed on the screen, as shown in FIG. 8, the map, road, and building near the current position are displayed as a plane, and the terminal device that has been positioned using the searched guide route R, GPS, or the like is used. The screen configuration is such that the current position is superimposed and displayed as the current position mark P. FIG. 8 shows an example in which the portable terminal in the pedestrian navigation system is a terminal device, and the current position mark R is indicated by a doll mark. In FIG. 8, a, b, and c are buttons for linking to a menu screen or the like.

  On the other hand, when the map display at the position corresponding to the position of FIG. 8 is displayed on a three-dimensional screen, the map near the current position and the road are three-dimensionally displayed as a bird's eye view or a three-dimensional polygon figure, and the building is three-dimensional in the height direction. It is displayed in 3D with an image that can be seen. The screen configuration is such that the current position of the terminal device is superimposed and displayed as a current position mark P using GPS or the like.

  As described above, the positioning position by GPS has an error of about 10 m. By correcting the current position measured by the matching process on the road or the guide route, the current position is displayed so as to move on the road or the guide route. It is generally well known that this error becomes even larger due to the effects of multipath in places where high buildings are densely packed, such as in front of the station and downtown. For this reason, a certain allowable error range is defined in the above-described matching process, and an error exceeding the allowable range may occur.

In addition, the reasons for the current position deviating from the route are, for example, (1) When the user makes a mistake and deviates from the route. (2) A user intentionally leaves the route and stops at a store or the like. Etc. If the user makes a mistake in the way as in (1) and deviates from the route, the user actually deviates from the route (guide route). It is necessary to switch to the current location display.

  Further, when the user intentionally leaves the route and stops at a store or the like as in (2), particularly in a place where there are many buildings, the positioning position by GPS is affected by multipath, and the positioning accuracy is lowered. At this time, if the positioning error exceeds the allowable error range of matching, the current position is displayed at an incorrect position.

  The three-dimensional display is easy to understand when the scenery that is actually seen matches the display of the device, but if the display is suddenly switched to a different place, it is confusing to understand the position. You may not know your current location at all. The reason is that, in the three-dimensional display, a route or road is hidden in a three-dimensional structure such as a building, so that the two-dimensional positional relationship cannot be instantaneously read like a map (plan view) in the two-dimensional display. It is.

  For this reason, in either case (1) or (2) above, when operating in the display mode for displaying the map display three-dimensionally, the current position measurement is performed from the state where the matching process is performed. When the error exceeds the allowable error range of matching and the current location is displayed, the map display as shown in FIG. 9 is changed to the map display as shown in FIG. 10 and the user is confused. 9 and 10 are map display screens displayed when a mobile phone is used as a terminal device. (When the mobile phone is a terminal device, the moving direction of the mobile phone is detected by the built-in electronic compass)

  FIG. 9 is a screen configuration diagram showing an example of a map display screen that is operating in a three-dimensional display mode and in which matching processing is being performed. FIG. 10 is a diagram showing an error due to current position positioning exceeding the allowable error range of matching, It is a screen block diagram which shows the example of the map display screen of the state displayed. As shown in FIG. 9, while the matching process is being performed, the current position moves on the road or the guide route R as indicated by the bold line (solid line) in the figure, so the user can determine the relationship between the current position and the road. It can be easily visually recognized.

  If the error due to the current position positioning exceeds the allowable error range of matching and the current position is displayed, as shown in FIG. 10, the current position is out of the road and the guide route and is hidden in the three-dimensionally displayed building. As a result, the user cannot visually recognize the relationship between the displayed road and the current location, which causes confusion and confusion to the user.

  When the three-dimensional display displayed as shown in FIGS. 9 and 10 is displayed in the two-dimensional display mode, the display is displayed as shown in FIGS. As shown in FIG. 11, while the matching process is being performed, the current position moves on the road indicated by the thick line (solid line) or the guide route R as indicated by the current position mark P in the figure. The relationship between the road and the road can be easily recognized.

  When the error due to the current position positioning exceeds the allowable error range of matching and the current position is displayed, the current position mark P is located off the guide route R as shown in FIG. FIG. 10 shows a case where the current position is displayed three-dimensionally, and the current position mark is hidden behind the building in front of the road. That is, during operation in the three-dimensional display mode, the error due to the current position positioning exceeds the allowable error range of matching as described above, and when the current position display is displayed, the display suddenly changes from FIG. 9 to FIG. The problem is that the person cannot visually recognize the relationship between the displayed road and the current location, causing confusion and confusion.

  However, the electronic map display device disclosed in Patent Document 4 detects the tilt angle of the electronic map display device, and reads map information of a corresponding display format from the map information storage unit based on the detected tilt angle. This is a display and does not correspond to the case where the matching error exceeds the allowable range, and the above-mentioned problems cannot be solved.

  Further, the map display device disclosed in Patent Document 5 (a) when a plane map is displayed, switches the display to either a bird's-eye view map or a house map, and (b) a bird's-eye view map is displayed. If the three-dimensional bird's-eye view map is displayed, the display is switched to either the three-dimensional bird's-eye view map or the plane map. ) When a house map is displayed, the display is switched to a flat map, and as described in the electronic map display device of Patent Document 4, it does not correspond to the case where the matching error exceeds the allowable range, but is described above. The problem cannot be solved.

  The inventor of the present application has conducted various studies to solve the above problems, and as a result, in a navigation system having a display mode for displaying a route, a map, and a building in two dimensions, and a display mode for displaying in three dimensions. It is conceived that the above problem can be solved by switching to the 2D display mode when the error in matching that corrects the positioning error of the current position during operation in the 3D display mode exceeds the allowable range. The present invention has been completed.

  That is, the present invention aims to solve the above-described problems, and includes a navigation system, a terminal device, and a map having a display mode for displaying a route, a map, and a building in a two-dimensional manner, and a display mode for displaying in a three-dimensional manner. In the display method, when the error in the matching process for correcting the positioning error at the current position during operation in the three-dimensional display mode exceeds an allowable range, the map display including the current position can be easily displayed. An object of the present invention is to provide a terminal device and a map display method.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is
The route search means searches for the guide route from the departure point to the destination with reference to the search network data based on the route search conditions including the departure point and the destination, and the map, the guide route, and the positioning means have determined the current position. In a navigation system for displaying a current position mark indicating a position on a display means,
A first display mode in which the display is performed by a two-dimensional image display and a second display mode in which the display is performed by a three-dimensional image display;
Matching processing means for matching on a road or a guide route when a positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
When the display is in the second display mode, display control is performed to change the display to the first display mode when the error detection means detects that the positioning error is not within a predetermined allowable range. Features.

The invention according to claim 2 of the present application is the navigation system according to claim 1,
The matching processing means performs map matching processing for matching the current position measured by the positioning means on the road.

The invention according to claim 3 of the present application is the navigation system according to claim 1,
The matching processing means performs route matching processing for matching the current position measured by the positioning means on the guide route.

The invention according to claim 4 of the present application is the navigation system according to claim 1,
The error detecting means determines whether or not a distance between a matching road or guide route and a perpendicular to the current position measured by the positioning means is within a predetermined allowable range.

The invention according to claim 5 of the present application is the navigation system according to claim 1,
The error detecting means determines whether or not a distance between a current position previously determined by the positioning means and a current position determined this time is within a predetermined allowable range.

The invention according to claim 6 of the present application is the navigation system according to claim 1,
The display control is control for temporarily changing from the second display mode to the first display mode.

The invention according to claim 7 of the present application is the navigation system according to claim 1,
The display control is control for repeatedly changing the second display mode and the first display mode alternately at a predetermined interval.

The invention according to claim 8 of the present application is the navigation system according to claim 1,
The display control is characterized in that when the display is changed to the first display mode, the viewpoint position in the three-dimensional image display is set high and a two-dimensional image is approximately displayed.

The invention according to claim 9 of the present application is
A network is connected to a route search server in which a route search means searches for a guide route from the departure point to the destination by referring to the search network data based on a route search condition including the departure point and the destination and distributes it to the terminal device. A terminal device that is connected via a map and displays a current position mark indicating a current position measured by the guide route and the positioning means on the display means,
The terminal device has a first display mode in which the display is performed by two-dimensional image display and a second display mode in which the display is performed by three-dimensional image display,
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
When the display is in the second display mode, display control is performed to change the display to the first display mode when the error detection means detects that the positioning error is not within a predetermined allowable range. Features.

The invention according to claim 10 of the present application is the terminal device according to claim 9,
The matching processing means performs map matching processing for matching the current position measured by the positioning means on the road.

The invention according to claim 11 of the present application is the terminal device according to claim 9,
The matching processing means performs route matching processing for matching the current position measured by the positioning means on the guide route.

The invention according to claim 12 of the present application is the terminal device according to claim 9,
The error detecting means determines whether or not a distance between a matching road or guide route and a perpendicular to the current position measured by the positioning means is within a predetermined allowable range.

The invention according to claim 13 of the present application is the terminal device according to claim 9,
The error detecting means determines whether or not a distance between a current position previously determined by the positioning means and a current position determined this time is within a predetermined allowable range.

The invention according to claim 14 of the present application is the terminal device according to claim 9,
The display control is control for temporarily changing from the second display mode to the first display mode.

The invention according to claim 15 of the present application is the terminal device according to claim 9,
The display control is control for repeatedly changing the second display mode and the first display mode alternately at a predetermined interval.

The invention according to claim 16 of the present application is the terminal device according to claim 9,
The display control is characterized in that when the display is changed to the first display mode, the viewpoint position in the three-dimensional image display is set high and a two-dimensional image is approximately displayed.

The invention according to claim 17 of the present application is
The route search means searches for a guide route from the departure place to the destination by referring to the search network data based on the route search conditions including the departure point and the destination, and the map, the guide route, and the positioning means determine the current position. A map display method in a navigation system for displaying a current position mark indicating a position on a display means,
A first display mode in which the display is performed by two-dimensional image display and a second display mode in which the display is performed by three-dimensional image display;
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
A first step of determining whether or not a positioning error is within a predetermined allowable range in the error detection means when the display is in a second display mode;
And a second step of changing the display to the first display mode when it is determined in the first step that the positioning error is not within a predetermined allowable range.

The invention according to claim 18 of the present application is the map display method according to claim 17,
The matching processing means further includes a step of performing map matching processing for matching the current position measured by the positioning means on the road.

The invention according to claim 19 of the present application is the map display method according to claim 17,
The matching processing means further includes a step of performing route matching processing for matching the current position measured by the positioning means on the guide route.

The invention according to claim 20 of the present application is the map display method according to claim 17,
The first step is a process for determining whether or not a distance between a road to be matched or a guide route and a perpendicular to the current position measured by the positioning means is within a predetermined allowable range.

The invention according to claim 21 of the present application is the map display method according to claim 17,
The first step is a process for determining whether or not a distance between a current position previously determined by the positioning unit and a current position determined this time is within a predetermined allowable range.

The invention according to claim 22 of the present application is the map display method according to claim 17,
The second step is control for temporarily changing from the second display mode to the first display mode.

The invention according to claim 23 of the present application is the map display method according to claim 17,
The second step is control in which the second display mode and the first display mode are alternately and repeatedly changed at a predetermined interval.

The invention according to claim 24 of the present application is the map display method according to claim 17,
The second step is a control for displaying a two-dimensional image approximately by taking a high viewpoint position in the three-dimensional image display when changing to the first display mode for display. .

In the invention according to claim 1, the navigation system has a first display mode in which display is performed by two-dimensional image display and a second display mode in which display is performed by three-dimensional image display,
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
When the display is in the second display mode, when the error detecting means detects that the positioning error is not within a predetermined allowable range, the display is changed to the first display mode.
Therefore, if the positioning error exceeds the allowable range, the screen where the current position matched is displayed is not changed suddenly to the screen where the current position mark is displayed at the current location, and the screen is changed to a two-dimensional display screen. Therefore, the current position mark is not hidden behind the three-dimensionally displayed building, and the user is not confused. That is, the current position mark is displayed on the map displayed on the plane or the current location on the guide route, and the user can easily visually recognize the positional relationship between the map and the current location.

In the invention according to claim 2, in the navigation system according to claim 1, the matching processing means performs map matching processing for matching the current position measured by the positioning means on the road. In the invention according to claim 3, in the navigation system according to claim 1, the matching processing means performs route matching processing for matching the current position measured by the positioning means on the guide route.
Therefore, regardless of whether the matching process is map matching or route matching, if the positioning error exceeds the allowable range, the current position mark is displayed at the current location from the screen on which the matched current position is displayed. Since the screen is not suddenly changed to a two-dimensional display screen, the current position mark is not hidden behind the three-dimensionally displayed building, and the user is not confused.

According to a fourth aspect of the present invention, in the navigation system according to the first aspect, the error detection means includes a matching road or guide route and a perpendicular distance to the current position measured by the positioning means within a predetermined allowable range. It is determined whether or not there is. In the invention according to claim 5, in the navigation system according to claim 1, the error detection means is configured such that the distance between the current position previously measured by the positioning means and the current position determined this time is a predetermined allowable range. It is determined whether or not it is inside.
Therefore, even if the positioning means is either GPS positioning means or autonomous navigation means, if the positioning error exceeds the allowable range, the current position mark is displayed at the current location from the screen on which the matched current position is displayed. Since the screen is not suddenly changed to a two-dimensional display screen, the current position mark is not hidden behind the three-dimensionally displayed building, and the user is not confused.

  In the invention according to claim 6, in the navigation system according to claim 1, the display control is control for temporarily changing from the second display mode to the first display mode. Therefore, when the positioning error returns within the allowable range, the display mode can be returned to the three-dimensional display mode and the display mode desired by the user can be continued.

In the invention according to claim 7, in the navigation system according to claim 1, the display control is a control in which the second display mode and the first display mode are alternately and repeatedly changed at a predetermined interval.
Therefore, if the positioning error exceeds the allowable range, the screen where the current position matched is displayed is not changed suddenly to the screen where the current position mark is displayed at the current location, and the screen is changed to a two-dimensional display screen. Since the current position mark is not hidden behind the three-dimensionally displayed building, the user can alternate between the two-dimensional display and the three-dimensional display. It can be seen and no confusion will occur.

In the invention according to claim 8, in the navigation system according to claim 1, when the display control is changed to the first display mode and displayed, the viewpoint position in the three-dimensional image display is set high and approximated. This is control for displaying a two-dimensional image.
Therefore, when the positioning error exceeds the allowable range, an approximate two-dimensional display is not performed without suddenly changing from the screen on which the matched current position is displayed to the screen on which the current position mark is displayed at the current location. Since the screen is changed, the current position mark is not hidden behind the three-dimensionally displayed building, and the user is not confused. That is, the current position mark is displayed on the map displayed on the plane or the current location on the guide route, and the user can easily visually recognize the positional relationship between the map and the current location.

  In the invention according to claims 9 to 16, a terminal device constituting the navigation system according to claims 1 to 8, respectively, can be provided, and in the invention according to claims 17 to 24, The navigation system according to claims 1 to 8 and the map display method in the terminal device according to claims 9 to 16 can be provided.

  Hereinafter, specific examples of the present invention will be described in detail with reference to examples and drawings. In the following embodiments, a mobile phone is used as a terminal device, and includes a first display mode for two-dimensional display of a map and the like, and a second display mode for three-dimensional display, and performs route search and route guidance. Although the navigation system will be described as a specific example, the present invention is not limited to such an embodiment, and the terminal device may be a mobile terminal such as an in-vehicle terminal device. In this specification, a mobile terminal including a mobile terminal is generically named.

  FIG. 1 is a block diagram illustrating a configuration of the navigation system according to the first embodiment of the present invention. As shown in FIG. 1, the navigation system 10 includes a terminal device 20 and a route search server 30 connected via a network 12 such as the Internet. The route search server 30 includes route search means 316, search network data 317, map data (DB) 315, and building image data (DB) 318.

  If there is a route search request from the terminal device 20 including a route search condition such as the current position, destination, moving means (automobile, walking, transportation or combined use of walking and transportation), the search network data 317 is referred to. A plurality of guide routes are searched in order of the shortest guide route or route length that matches the route search condition. The guide route data obtained as a result of the search includes a plurality of unit map data (map data divided into areas of a predetermined size by latitude and longitude) and building image data 318 including the current position selected from the map data 315. Are distributed to the terminal device 20 together with the data of the building image on the unit map data selected from the above.

  The route search server 30 also includes a control unit 311, a communication unit 312, a distribution data editing unit 313, and a guide route data creating unit 314. Although not shown, the control unit 311 is a microprocessor having a RAM, a ROM, and a processor, and controls the operation of each unit by a control program stored in the ROM. The communication unit 312 is an interface for communicating with the terminal device 20 via the network 12. The guide route data creation means 314 creates guide route data, map data, guidance points, guidance data at guidance points, and the like searched as described above, and the distribution data editing means 313 stores the data such as the guide routes. Edit the data to be distributed to the device 20.

  On the other hand, the terminal device 20 is a mobile phone equipped with GPS positioning means 212 such as a GPS receiver, for example, and includes control means 211, GPS positioning means 212, autonomous navigation means 213, matching processing means 214, two-dimensional display control means. 215, three-dimensional display control means 216, communication means 217, distribution request editing means 218, distribution data storage means 219, error detection means 220, display means 221, operation / input means 222, and the like.

  Although not shown, the control unit 211 includes a microprocessor (CPU) having a RAM and a ROM, and controls the operation of each unit by a control program stored in the ROM. The operation / input means 222 is for operation / input means consisting of numeric keys, alphabet keys, other function keys, selection keys, scroll keys, and the like. From the menu screen displayed on the display means 221 as output means Various input operations are performed by selecting a desired menu or operating keys. Accordingly, the display unit 221 also functions as a part of the operation / input unit 222. The communication unit 217 is an interface for communicating with the route search server 30 via the network 12.

  When a user wants to request a route search from the route search server 30, the user operates the operation / input unit 222 on the terminal device 20, selects a route search from the service menu displayed on the display unit 221, Enter route search conditions such as location, means of transportation (automobile, walking, transportation, combined use of walking and transportation, etc.). The route search condition is edited into a distribution request to the route search server 30 by the distribution request editing unit 218 and transmitted to the route search server 30 via the communication unit 217.

Distribution data from the route search server 30 is temporarily stored in the distribution data storage unit 219, read out from the distribution data storage unit 219 as necessary, and displayed on the display unit 221. The terminal device 20 has a first display mode (hereinafter referred to as a two-dimensional display mode) for two-dimensionally displaying a map, a guide route, a building image, and the like included in the distribution data, and a second three-dimensionally displayed for three-dimensional display. It has a display mode (hereinafter referred to as a three-dimensional display mode), and the user can select any display mode to operate the terminal device.
The two-dimensional display control unit 215 performs control to display a map, a guidance route, a building image, and the like as a two-dimensional image (planar image), and the three-dimensional display control unit 215 displays the map, the guidance route, the building image, etc. Control to display as an image (for example, a bird's eye view) is performed.

  The GPS positioning means 212 periodically measures the current position of the terminal device 20 and acquires the current position (latitude / longitude). A current position mark indicating the current position measured by the GPS positioning means 212 is displayed superimposed on an image such as a map or a guide route displayed on the display means 221.

  The current position measured by the GPS positioning means includes an error of about 10 m, and the positioning error becomes even larger in a place where the influence of multipath is strong. Therefore, the matching processing unit 214 performs processing for correcting the current position measured by the GPS positioning unit 212 to the nearest road or guide route on the map. As described above, the error may exceed a predetermined range (allowable range). In this case, if the matching process is performed, the current position mark is displayed on a road or the like different from the guide route, which causes confusion to the user. Therefore, when the error exceeds the allowable range, the current position mark is displayed at the current position measured without matching processing (this is referred to as the current location in order to distinguish it from the current position subjected to matching processing).

  Here, when the mobile terminal 20 is operating in the three-dimensional display mode, if the positioning error exceeds the allowable range, the current position mark P is displayed at the current location as described with reference to FIGS. If the current position mark P is hidden behind a three-dimensional building because it suddenly changes to the screen, the user loses sight of the current position and the positional relationship between the map and the road, causing confusion. End up. Therefore, in this embodiment, the error detection unit 220 determines whether or not the positioning error of the current position measured by the GPS positioning unit 212 exceeds the allowable range. Is switched from the 3D display mode to the 2D display mode.

  As a result, the display image displayed on the display means 221 is two-dimensionally displayed as shown in FIG. 12, that is, the current position mark P is displayed at the current location on the map or guide route R displayed on the plane, and the user can The positional relationship between the map and the current location can be easily visually recognized. Whether or not the positioning error exceeds the allowable range is determined by determining the distance to the road or route that is closest to the current position of the positioning (the shortest length when the perpendicular is dropped from the current position) (the length of the perpendicular). Can be discriminated based on whether or not it exceeds a predetermined length.

  Note that the autonomous navigation means 213 is used to calculate the current position and traveling direction of the terminal device 20 in places where GPS satellite signals cannot be received, such as in tunnels and underground malls, and includes an acceleration sensor, a geomagnetic sensor, and the like. The current position and the traveling direction are calculated by dead reckoning navigation. In-vehicle terminal devices may further include a vehicle speed center and a steering angle sensor.

  In the route search server 30, the search network data 317 includes road network data 317A for searching a route by foot or a car, and traffic network data 317B for searching a route using a transportation facility. This makes it possible to search for walking, a route by car, and a route using both walking and transportation. These network data are structured as follows.

  For example, when the road is composed of roads A, B, and C as shown in FIG. 2, the end points, intersections, and inflection points of the roads A, B, and C are used as nodes, and the roads connecting the nodes are directed links. From the link cost data with the node data (node latitude / longitude), link data (link number) and link cost of each link (link distance or time required to travel the link) as data Composed.

  That is, in FIG. 2, ◯ and ◎ indicate nodes, and ◎ indicates a road intersection. Directional links connecting the nodes are indicated by arrow lines (solid line, dotted line, two-dot chain line). As for the links, there are links facing in the upward and downward directions of the road, but in FIG. 2, only the links in the direction of the arrows are shown for the sake of simplicity.

  When route search is performed using such road network data as a route search database, links linked from the starting node to the destination node are traced to accumulate the link cost, thereby minimizing the accumulated link cost. Search and guide the route. That is, in FIG. 2, when a route search is performed with the departure point as the node AX and the destination as the node CY, the road travels from the node AX to the road A, turns right at the second intersection, enters the road C, and reaches the node CY. The link cost is accumulated sequentially, and a route that minimizes the accumulated link cost is searched for and guided.

  Although other routes from the node AX to the node CY are not shown in FIG. 2, in reality there are other such routes, so a possible route from the node AX to the node CY is similarly searched. Of these routes, the route with the lowest link cost is determined as the optimum route. This method is performed by, for example, a known method called the Dijkstra method.

  On the other hand, the traffic network data for route search of the transportation system is configured as follows. For example, as shown in FIG. 3, in the case of traffic routes A, B, and C, each station (each airport on an aircraft route) provided on each traffic route A, B, and C is a node, and the nodes are connected. A section is represented by a directional link, and node data (latitude / longitude) and link data (link number) are network data. In FIG. 3, ○ and ◎ indicate nodes, ◎ indicates a transit point (such as a transfer station) on a traffic route, and a directional link connecting each node is indicated by an arrow line (solid line, dotted line, two points). This is indicated by a chain line). As for the links, there are links facing in the upward and downward directions of the traffic route, but in FIG. 3, only the links in the direction of the arrows are shown for the sake of simplicity.

  However, the traffic network basically has a different link cost compared to the road network. In other words, in the road network, the link cost is fixed and static, but in the traffic network, as shown in FIG. 3, trains and airplanes (hereinafter referred to as individual trains and airplanes) that operate the traffic route. A plurality of means of transportation). The time of departure from one node and the time of arrival at the next node are determined for each means of transportation (specified by timetable data and operation data), and individual routes do not necessarily link to adjacent nodes. There is a case. This is the case, for example, with express trains and trains that stop at each station. In such a case, a plurality of different links exist on the same traffic route, and the required time between nodes may differ depending on the transportation means.

  In the transportation network illustrated in FIG. 3, a plurality of transportation means (routes) Aa to Ac... Exist on the same link of the transportation route A, and a plurality of transportation means (routes) Ca to Cc. Will do. Therefore, unlike a simple road network, the transportation network of a transportation facility has a data amount proportional to the total number of transportation means (routes such as individual airplanes and trains). For this reason, the data of the traffic network becomes a huge amount of data compared to the data amount of the road network. Accordingly, much time is required for route search accordingly.

In order to search for a route from a certain departure point to a certain destination using such traffic network data, all the means of transportation that can be used (ride) when arriving from the departure point to the destination are searched. It is necessary to specify the means of transportation that matches the search conditions.
For example, in FIG. 3, when performing a route search with the departure point as the node AX of the traffic route A and specifying a certain departure time and the destination of the node CY of the traffic route C, the route operates on the traffic route A. Of the transportation means Aa to Ac..., All transportation means after the departure time are sequentially selected as the departure route. And, based on the arrival time at the transit node on the transit route C, among all the transit means Ca-Cc... The total time required for each route, the number of transfers, and the like are guided.

  Next, the operation procedure of the navigation system 10 will be described with reference to the flowchart of FIG. The GPS positioning means 212 periodically receives GPS satellite signals in the process of step S10, and calculates (acquires) the current position (latitude / longitude of the location where the terminal device is located) in the process of step S11.

  In the process of step S12, the matching processing unit 214 performs a process of drawing a perpendicular line to the road or route near the current position, and correcting the current position to the road or route having the shortest perpendicular line. At this time, in the process of step S13, it is determined in the error detection means 220 whether the current position field positioning error exceeds a predetermined allowable range, that is, whether the length of the perpendicular exceeds a predetermined length.

  If the positioning error is within the allowable range, the process of the matching processing unit 214 is confirmed, and it is determined in the process of step S14 whether the terminal device 20 is operating in the two-dimensional display mode or the three-dimensional display mode. If operating in the two-dimensional display mode, the two-dimensional display control means 215 displays the map, route, and current position mark on the display means 221 in a two-dimensional manner in the process of step S15. If operating in the three-dimensional display mode, the three-dimensional display control means 216 displays the map, route, and current position mark two-dimensionally on the display means 221 in the process of step S16.

  On the other hand, if it is determined in the determination process of step S13 that the positioning error exceeds the allowable range, the processing result of the matching processing means 214 is canceled, the current position determined as the current position is determined, and the process proceeds to step S15. The display mode of the terminal device 20 is forcibly changed to the two-dimensional display mode, and the two-dimensional display control unit 215 displays the map, the route, and the current position mark on the display unit 221 in two dimensions.

  By controlling in this way, the display image displayed on the display means 221 is displayed two-dimensionally as shown in FIG. 12, that is, the current position mark is displayed on the planar display map or the current location on the guide route, The user can easily visually recognize the positional relationship between the map and the current location.

  Note that when the terminal device 20 is positioning the current position by the autonomous navigation means 213, the positioning error in the discrimination processing in step S13 is a distance between the current position measured last time and the current position measured this time is predetermined. Judgment is made based on whether it is within the allowable range.

  In the first embodiment, when the positioning error in the GPS positioning unit 212 exceeds the allowable range, the terminal device 20 is forcibly changed to the 2D display mode even if the terminal device 20 is operating in the 3D display mode. However, as shown in the second embodiment, the display in the two-dimensional display mode and the display in the three-dimensional display mode can be alternately and repeatedly changed at a constant cycle. According to this configuration, when the matching process is not valid (positioning error exceeds the allowable range), the guidance can be changed to the two-dimensional display, and the user is clearly informed that the state has been reached. Can do.

  FIG. 5 is a block diagram illustrating a configuration of the navigation system 10 according to the second embodiment of the present invention. The navigation system 10 is basically the same as the configuration shown in FIG. 1 except that the terminal device 20 is further provided with a timer means 223 as shown in FIG. In FIG. 5, the other elements are the same as those in the first embodiment shown in FIG. 1, and the same parts as those in FIG.

  The timer means 223 repeatedly measures the time T when the positioning error in the GPS positioning means 212 exceeds an allowable range, and the terminal device is set to the three-dimensional display mode during the measurement time 0 to T / 2. The terminal device 20 is switched to the two-dimensional display mode between T / 2 and T / 2.

  FIG. 6 is a flowchart showing a processing procedure of the navigation system 10 in the second embodiment. In the process of step S20, the GPS positioning means 212 periodically receives GPS satellite signals, and in the process of step S21, calculates (acquires) the current position (latitude / longitude of the location where the terminal device is located).

  In the process of step S22, the matching processing means 214 performs a process of correcting the current position on the road or route with the shortest perpendicular line by dropping a perpendicular to the road or route near the current position. In the process of step S23, it is determined whether the terminal device 20 is operating in the two-dimensional display mode or the three-dimensional display mode. If operating in the two-dimensional display mode, the process proceeds to step S26, and if operating in the three-dimensional display mode, the process proceeds to step S24. When the terminal device 20 is operating in the two-dimensional display mode, the two-dimensional display control unit 215 displays the map, the route, and the current position mark on the display unit 221 in a two-dimensional manner in the process of step S26.

  When the terminal device 20 is operating in the three-dimensional display mode, whether the positioning error of the current position exceeds the predetermined allowable range in the error detection unit 220 in the process of step S24, that is, the length of the perpendicular is a predetermined value. It is determined whether the length is exceeded. If the positioning error is within the allowable range, the processing of the matching processing unit 214 is confirmed, and the three-dimensional display control unit 216 displays the map, the route, and the current position mark on the display unit 221 in a three-dimensional manner in the process of step S27.

  On the other hand, if it is determined that the positioning error exceeds the allowable range in the determination process in step S24, the processing result of the matching processing unit 214 is canceled, the current position determined as the current position is determined, and the process proceeds to step S25. The timer means 223 is activated. When the measurement time of the timer means 223 is 0 to T / 2, the process proceeds to step S27, the terminal device 20 is set to the three-dimensional display mode, and the three-dimensional display control means 216 displays a map, a route, and a current position mark on the display means 221. 3D display. When the measurement time is between T / 2 and T, the process proceeds to step S26, the terminal device 20 is set to the two-dimensional display mode, and the two-dimensional display control unit 215 displays the map, route, and current position mark on the display unit 221 in two dimensions. To do.

  When the terminal device 20 is positioning the current position by the autonomous navigation means 213, the positioning error in the discrimination processing in step S24 is the same as the first embodiment between the current position measured last time and the current position measured this time. Is determined based on whether or not the distance is within a predetermined allowable range.

  As described above in detail, when the terminal device 20 is operating in the three-dimensional display mode, even if the current position positioning error in the GPS positioning unit 212 exceeds the allowable range of the matching process and the current position is displayed, 2 By changing to the three-dimensional display, the current position mark is not hidden behind the building, and the user is not confused with the current position and the surrounding map.

  In the first and second embodiments, the example in which the display mode of the terminal device is controlled to the two-dimensional display mode when it is determined that the positioning error exceeds the allowable range is shown. However, the two-dimensional display is not necessarily performed. Since the current position mark in the current position display does not have to be hidden in the three-dimensional displayed building image, the viewpoint position is set high as shown in the bird's-eye view shown in FIG. The same effect can be obtained by displaying the height low and displaying the current position mark so as not to be hidden behind the building in front, so that the display is close to a two-dimensional (planar) display. Therefore, the two-dimensional display in the present invention includes a display approximated to the two-dimensional display by such a bird's eye view with a high viewpoint position.

  The present invention can be implemented by an in-vehicle navigation system and a pedestrian navigation system using a mobile phone. In particular, the present invention is effective when applied to a navigation system that uses a mobile phone as a terminal device, which is not capable of autonomous navigation using vehicle speed pulses or the like but mainly uses satellite navigation that relies on GPS.

It is a block diagram which shows the structure of the navigation system concerning Example 1 of this invention. It is a schematic diagram for demonstrating the structure of road network data. It is a schematic diagram for demonstrating the structure of traffic network data. It is a flowchart which shows the operation | movement procedure of the navigation system concerning Example 1 of this invention. It is a block diagram which shows the structure of the navigation system concerning Example 2 of this invention. It is a flowchart which shows the operation | movement procedure of the navigation system concerning Example 2 of this invention. It is a display screen block diagram by the bird's-eye view which made the position of the viewpoint high and was brought close to the two-dimensional map display. It is a screen block diagram which shows the example of a two-dimensional map display screen. It is a screen block diagram which shows the example of the map display screen of the state which operate | moves in a three-dimensional display mode and the matching process is performed. It is a screen block diagram which shows the example of the map display screen of the state by which the error by current position positioning exceeded the error tolerance | permissible_range of matching, and became the present location display. It is a screen block diagram which shows the two-dimensional map display screen in the position corresponded to the position of FIG. It is a screen block diagram which shows the two-dimensional map display screen in the position corresponded to the position of FIG.

Explanation of symbols

10. Navigation system 12 ... Network 20 ... Terminal device 211 ... Control means 212 ... GPS positioning means 213 ... Autonomous navigation means 214 ... Matching processing means 215 ... 2D display control means 216 3D display control means 217 Communication means 218 Delivery request editing means 219 Delivery data storage means 220 Error detection means 221 Display means 222 ... operation / input means 223 ... timer means 30 ... route search server 311 ... control means 312 ... communication means 313 ... distribution data editing means 314 ... guide route data creation Means 315 Map data (DB)
316 ... Route search means 317 ... Search network data 317A ... Road network data 317B ... Traffic network data 318 ... Building image data (DB)

Claims (24)

The route search means searches for a guide route from the departure place to the destination by referring to the search network data based on the route search conditions including the departure point and the destination, and the map, the guide route, and the positioning means determine the current position. In a navigation system for displaying a current position mark indicating a position on a display means,
A first display mode in which the display is performed by two-dimensional image display and a second display mode in which the display is performed by three-dimensional image display;
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
When the display is in the second display mode, display control is performed to change the display to the first display mode when the error detection means detects that the positioning error is not within a predetermined allowable range. A featured navigation system.   The navigation system according to claim 1, wherein the matching processing unit performs a map matching process for matching a current position measured by the positioning unit on a road.   The navigation system according to claim 1, wherein the matching processing unit performs route matching processing for matching a current position measured by the positioning unit on a guide route.   The said error detection means discriminate | determines whether the distance of the perpendicular to the road or guide route to match and the current position measured by the positioning means is in a predetermined tolerance range. Navigation system.   2. The error detection unit determines whether or not a distance between a current position previously determined by the positioning unit and a current position measured this time is within a predetermined allowable range. Navigation system.   The navigation system according to claim 1, wherein the display control is control for temporarily changing from the second display mode to the first display mode.   The navigation system according to claim 1, wherein the display control is control for alternately and repeatedly changing the second display mode and the first display mode at a predetermined interval.   The display control is control for displaying a two-dimensional image approximately by taking a high viewpoint position in a three-dimensional image display when changing to the first display mode. The navigation system according to 1. A network is connected to a route search server in which a route search means searches for a guide route from the departure point to the destination by referring to the search network data based on a route search condition including the departure point and the destination and distributes it to the terminal device. A terminal device that is connected via a map and displays a current position mark indicating a current position measured by the guide route and the positioning means on the display means,
The terminal device has a first display mode in which the display is performed by two-dimensional image display and a second display mode in which the display is performed by three-dimensional image display,
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
When the display is in the second display mode, display control is performed to change the display to the first display mode when the error detection means detects that the positioning error is not within a predetermined allowable range. Characteristic terminal device.   The terminal device according to claim 9, wherein the matching processing unit performs map matching processing for matching a current position measured by the positioning unit on a road.   The terminal device according to claim 9, wherein the matching processing unit performs route matching processing for matching the current position measured by the positioning unit on the guide route.   The said error detection means determines whether the distance of the perpendicular to the road or guide route to be matched and the current position measured by the positioning means is within a predetermined allowable range. Terminal equipment.   The error detection means determines whether or not a distance between a current position measured by the positioning means last time and a current position measured this time is within a predetermined allowable range. Terminal equipment.   The terminal device according to claim 9, wherein the display control is control for temporarily changing from the second display mode to the first display mode.   The terminal device according to claim 9, wherein the display control is control for alternately and repeatedly changing the second display mode and the first display mode at a predetermined interval.   The display control is control for displaying a two-dimensional image approximately by taking a high viewpoint position in a three-dimensional image display when changing to the first display mode. 9. The terminal device according to 9. The route search means searches for a guide route from the departure place to the destination by referring to the search network data based on the route search conditions including the departure point and the destination, and the map, the guide route, and the positioning means determine the current position. A map display method in a navigation system for displaying a current position mark indicating a position on a display means,
A first display mode in which the display is performed by two-dimensional image display and a second display mode in which the display is performed by three-dimensional image display;
Matching processing means for matching on a road or a guide route when the positioning error of the current position measured by the positioning means is within a predetermined allowable range;
Error detection means for determining whether or not the positioning error is within a predetermined allowable range,
A first step of determining whether or not a positioning error is within a predetermined allowable range in the error detection means when the display is in a second display mode;
A map display method comprising: a second step of changing the display to the first display mode when it is determined in the first step that the positioning error is not within a predetermined allowable range.   The map display method according to claim 17, wherein the matching processing unit further includes a step of performing a map matching process for matching a current position measured by the positioning unit on a road.   The map display method according to claim 17, wherein the matching processing unit further includes a step of performing a route matching process for matching a current position measured by the positioning unit on a guide route.   The first step is a process for determining whether or not a distance between a road to be matched or a guide route and a perpendicular to a current position measured by the positioning means is within a predetermined allowable range. Item 18. The map display method according to Item 17.   The first step is a process of determining whether or not a distance between a current position previously determined by the positioning means and a current position determined this time is within a predetermined allowable range. Item 18. The map display method according to Item 17.   The map display method according to claim 17, wherein the second step is control for temporarily changing from the second display mode to the first display mode.   The map display method according to claim 17, wherein the second step is a control for alternately and repeatedly changing the second display mode and the first display mode at a predetermined interval.   The second step is a control for displaying a two-dimensional image approximately by taking a high viewpoint position in the three-dimensional image display when changing to the first display mode for display. The map display method according to claim 17.

Images