JP2009042132A - Apparatus and method for map display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correct a current position according to a user's means of transportation in a system for displaying a current position on a map. <P>SOLUTION: A cellular phone as a map display device determines a user's means of transportation and acquires from a server route data indicating a route to travel. The cellular phone sets a correction region for correcting a current position according to the user's means of transportation. When the cellular phone detects the current position by a GPS receiver, the cellular phone determines whether the current position has been detected in the correction region set according to the user's means of transportation. In the case where the current position has been detected in the correction region, the cellular phone corrects the current position to a position on a recommended route. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for correcting a current position measured by GPS or the like.

  In recent years, map display devices that measure the current position using GPS (Global Positioning System) and display the position on a map have become widespread. In positioning technology using GPS, it is known that an error of several meters to several tens of meters occurs depending on the reception status of radio waves from satellites and the number of captured satellites. Therefore, in the conventional map display device, when there is an error in the current position measured, the current position is forcibly corrected to a position on a nearby road or route (the following patent document). 1).

JP 2003-16699 A

  Conventional map display devices are often designed on the assumption that they are mounted on a vehicle, and the range in which correction is performed is also set in accordance with the movement characteristics of the vehicle. For example, Patent Document 1 describes that if the current position is measured within a range of 200 m to the left or right of the guide route, the current position is corrected on the guide route.

  However, in recent years, GPS receivers are being installed in small devices such as mobile phones and PDAs. Such a small device can be used not only in a vehicle but also for walking or traveling by bicycle. Therefore, it is becoming difficult for the conventional current position correction method to cope with various moving means of the user.

  In consideration of such problems, the problem to be solved by the present invention is to perform correction of the current position in accordance with the moving means of the user in an apparatus that displays the current position on a map.

  Based on the above problems, a map display device according to an aspect of the present invention is configured as follows.

A map display device according to one aspect of the present invention is provided.
A map display device that displays a current position on a map,
A data acquisition unit for acquiring map data including information indicating a route to be traveled;
A moving means discriminating unit for discriminating the type of moving means of the user;
A position detector that sequentially detects the current position;
A correction area setting unit that sets a correction area that is a range for correcting the detected current position to a position on the route according to the type of the determined moving means;
A correction unit that corrects the current position to a position on the path only when the current position is detected within the set correction area;
A display unit that displays the corrected current position on a map image represented by the map data.

  According to the map display device of the above aspect, the range of the correction area for determining whether or not to correct the current position is set according to the type of moving means of the user. Therefore, when a measurement error occurs at the current position, it is possible to perform a preferable correction according to the moving means of the user. Note that the map image displayed on the screen by the display unit may be represented in a raster format or a vector format.

  In the map display device according to the aspect described above, the correction area setting unit sets, as the correction area, an area having a spread by a distance determined according to the type of the moving unit in the left-right direction with the route as a center. be able to. This makes it possible to vary the range of the correction area in the left-right direction centered on the route according to the type of the moving means.

  In the map display device according to the aspect described above, when the moving unit is a vehicle, the correction area setting unit sets, as the correction area, the current position corrected last time as the rear end, and the type of the moving unit from the rear end. It is possible to set a region having a tip in front by a predetermined distance according to.

  When the vehicle is traveling on the route, it is considered that there is almost no back. Therefore, if a correction area with the current position corrected last time as the rear end is set as in this mode, the current position is corrected when the current position is detected behind the current position detected last time. It becomes unnecessary to do. As a result, it is possible to suppress blurring in the displayed map image. Further, according to the above aspect, since the length along the path of the correction area is set according to the moving unit, it is possible to vary the range for correcting the current position according to the speed of the moving unit. Become.

  In the map display device according to the aspect described above, when the moving unit is walking, the correction area setting unit includes, as the correction area, an area that extends forward and backward by a predetermined distance from the current position corrected last time. Can be set.

  When the moving means is walking, the pedestrian may not only move forward on the route but also deviate left and right or move in the opposite direction. Therefore, by providing a correction area behind the current position corrected last time as in this aspect, it is possible to perform correction in consideration of the pedestrian's movement characteristics. It should be noted that the forward distance and the backward distance from the current position corrected last time do not have to be the same.

  In the map display device according to the aspect described above, the tip of the correction area may be formed in a triangular shape having a vertex on the route. By doing so, the range in which the measurement error is allowed can be narrowed as the detected current position moves further forward from the previously corrected current position. As a result, highly accurate correction can be performed.

  In the map display device according to the aspect described above, the correction area setting unit may set the correction area according to the determined moving means and the attribute of the route. The attribute of the route refers to a road type such as a general road or a highway. With such an aspect, it becomes possible to set the correction area according to characteristics such as the speed limit of the route as well as the type of moving means.

  In the map display device according to the aspect described above, the moving means determination unit may determine the type of the moving means based on the sequentially detected current position history. In such an aspect, the range of the correction area can be set dynamically, so that the user does not need to change the setting each time the moving means is changed, and convenience is improved. become.

  In the map display device of the above aspect, the correction area setting unit can adjust the correction area according to the determined speed of the moving means. By doing so, it becomes possible to dynamically adjust the correction area according to not only the type of moving means but also its speed.

  The map display device according to the aspect further includes a reroute area that is an area outside the correction area and for determining whether to acquire a route different from the route to be traveled according to the determined moving means. When the reroute area setting unit to be set and the current position are detected within the set reroute area, a new route that is different from the route and starts from the current position is acquired. And a reroute unit that performs the above operation.

  According to such an aspect, when the current position greatly deviates from the current route and is detected in the reroute area, a new route starting from the current position can be acquired. Since the reroute area is also set according to the type of moving means, the convenience for the user can be further enhanced.

  In the map display device according to the aspect described above, the display unit detects the current position when the current position is detected in a dead area outside the correction area and inside the reroute area. The current position may be displayed on the map image as it is.

  In this manner, even if the current position is detected outside the correction area, a new route is not immediately acquired. Therefore, it becomes possible to suppress that the response of a map display falls. Further, in such a mode, when the current position is detected in the insensitive area, it can be suggested to the user that the route is off, so the user waits for acquisition of a new route. It is possible to return to the route smoothly without any problems.

  In the map display device according to the above aspect, the data acquisition unit can acquire the map data from a predetermined server by wireless communication. According to such an aspect, it is not necessary to provide the map display device itself with a storage device for storing the map data, so that the device can be made compact and the manufacturing cost can be reduced. Further, by storing the map data in a predetermined server, the map data can be easily updated.

  In addition to the configuration as the map display device described above, the present invention can also be configured as a map display method or a computer program. Such a computer program may be recorded on a computer-readable recording medium. As the recording medium, for example, various media such as a flexible disk, a CD-ROM, a DVD-ROM, a magneto-optical disk, a memory card, and a hard disk can be used.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Schematic configuration of map display system:
B. Route search process:
C. Map display processing:
D. Variations:

A. Schematic configuration of map display system:
FIG. 1 is an explanatory diagram showing a schematic configuration of a map display system 10 as an embodiment of the present invention. As shown in the figure, the map display system 10 of the present embodiment includes a route search server 100, a map server 150, and a mobile phone 200 as a map display device. The mobile phone 200 according to the present embodiment includes a GPS receiver 201 and has a function of performing route guidance using the GPS receiver 201. The mobile phone 200 functions as a pedestrian navigation device when carried by a person, and functions as a car navigation device when used in a vehicle.

  The mobile phone 200 includes a GPS receiver 201, a display panel 202, an audio output unit 203, a wireless communication circuit 205, a command input unit 206, a main control unit 210, and a call control unit 220.

  The main control unit 210 is a controller for controlling each unit of the mobile phone 200. The main control unit 210 includes a CPU 211, a RAM 212, and a ROM 213. The CPU 211 implements various processes to be described later by loading the control program stored in the ROM 213 into the RAM 212 and executing it. The main control unit 210 corresponds to the “moving means determination unit”, “correction area setting unit”, “correction unit”, and the like of the present application.

  The GPS receiver 201 is a device that receives radio waves transmitted from artificial satellites that constitute a GPS (Global Positioning System / Global Positioning System). The main control unit 210 detects (positions) the current position based on the radio wave received by the GPS receiver 201. If the GPS receiver 201 can receive radio waves from three satellites, the main control unit 210 can detect a two-dimensional current position, and if the GPS receiver 201 can receive radio waves from four satellites, 3 A dimensional current position can be detected. In addition, if radio waves can be received from five or more satellites, the current position can be detected with high accuracy.

  The display panel 202 includes a liquid crystal display and a drive circuit that drives the liquid crystal display. The liquid crystal display has a resolution of, for example, 480 pixels × 640 pixels (VGA). The main control unit 210 controls the display panel 202 to display a map image, a recommended route, a current position, and the like. The display panel 202 is not limited to a liquid crystal display, and various display devices such as an organic EL display can be employed.

  The voice output unit 203 includes a speaker for outputting voice during route guidance, a circuit for driving the speaker, and the like.

  The wireless communication circuit 205 is a circuit for performing data communication or voice communication with the base station BS. A route search server 100 and a map server 150 are connected to the base station BS via the Internet INT. The wireless communication circuit 205 can access the route search server 100 and the map server 150 via the base station BS.

  The call control unit 220 is a circuit that performs incoming calls and calls for voice calls, conversion of voice signals and electrical signals, and the like.

  The command input unit 206 includes a group of buttons such as a numeric keypad 206a and a cursor key 206b. By using these buttons, the user can input the starting point and destination used for route search.

  The map server 150 includes a communication unit 152, a control unit 154, and a storage device 155. The storage device 155 stores a map database 156. The communication unit 152 can communicate with the mobile phone 200 via the Internet INT. In the map database 156, map data supplied to the mobile phone 200 is recorded in a vector format. This map data includes data representing the shape of topography, buildings, roads, and the like. When there is a map data acquisition request from the mobile phone 200, the control unit 154 searches the map database 156 for map data in the specified range, and transmits the map data to the mobile phone 200 via the communication unit 152.

  The route search server 100 includes a communication unit 102, a control unit 104, and a storage device 105. The communication unit 102 can communicate with the mobile phone 200 via the Internet INT. The storage device 105 stores a route database 106 in which road connection states and road attributes are recorded. The state of road connection is represented by node data composed of latitude and longitude such as intersections and branch points, and link data representing roads by line segments connecting the node data. When there is a route search request from the mobile phone 200, the route search server 100 uses the route database 106 to search for a recommended route connecting the designated departure place and destination. Then, the recommended route data obtained as a result of the search is transmitted to the mobile phone 200 via the communication unit 102.

  In the present embodiment, the control unit 104 of the route search server 100 performs route search using the route database 106 stored in its own storage device 105. However, when the route database 106 is stored in the map server 150, the route database 106 may be read and used via the Internet INT. Note that the route search server 100 and the map server 150 can be configured as an integrated server. The map data transmitted from the map server 150 to the mobile phone 200 and the recommended route data transmitted from the route search server to the mobile phone 200 can be taken together as “map data” in a broad sense.

B. Route search process:
FIG. 2 is a flowchart of route search processing executed by the main control unit 210 of the mobile phone 200. This process is a process executed when the user calls the route guidance function of the mobile phone 200 using the command input unit 206.

  When the route search process is started, first, the main control unit 210 receives a command from the user via the command input unit 206 as necessary, such as a departure point, a destination, a waypoint, a search condition, and a moving means to be used. An input such as a type is accepted (step S10). The departure point can be the current position detected by the GPS receiver 201. The search conditions are conditions such as necessity of using VICS (Vehicle Information and Communication System) information, designation of departure time and arrival time, whether to use a sidewalk with stairs or a roof. The moving means to be used is selectively input from a choice of “walking”, “bicycle”, “car”, “train”, etc. displayed on the display panel 202 by a predetermined GUI (graphical user interface). can do. Upon receiving these inputs, the main control unit 210 transmits a route search request signal to the route search server 100 using the wireless communication circuit 205 (step S20). This request signal includes the information input in step S10.

  When the route search server 100 receives the route search request signal from the mobile phone 200, the route search server 100 refers to the route database 106 stored in the storage unit 105 and connects the departure point and the destination included in the request signal (route point). If the route is set, a recommended route that satisfies the set search condition is calculated. The recommended route can be calculated using, for example, a well-known Dijkstra method. When the route search server 100 calculates the recommended route, it returns data representing the shape of the route to the mobile phone 200 in the form of a vector as recommended route data. In the recommended route data, information indicating the type of the road is recorded as attribute information for each road constituting the route. The types of roads include types such as general roads and highways. When the route database 106 is prepared for each moving means, the route search server 100 obtains a recommended route using the route database corresponding to the moving means input by the user. In this way, a route suitable for the user's moving means can be guided. Further, when the type of moving means is not input from the user, a recommended route suitable for a default moving means (for example, a vehicle) may be obtained. Alternatively, a moving unit may be automatically selected according to the distance between the departure point and the destination, and a recommended route suitable for the moving unit may be obtained. For example, if the distance between the departure point and the destination is within 500 m, walk, if it is 500 m to 2 km, walk and vehicle, if it is more than 500 km, if it is 500 km or more, use vehicles, trains, aircraft The path to be included can be searched. Of course, the user can arbitrarily select the moving means by himself.

  When receiving the recommended route data from the route search server 100 (step S30), the main control unit 210 of the mobile phone 200 stores the recommended route data in the RAM 212 (step S40). The recommended route data stored in the RAM 212 is displayed on the display panel 202 in a map display process described later.

C. Map display processing:
FIG. 3 is a flowchart of the map display process executed subsequent to the route search process shown in FIG. In the present embodiment, it is assumed that the main control unit 210 of the mobile phone 200 executes this process once per second. The execution timing may be changed according to the moving means and moving speed of the user. For example, if the moving means is a vehicle, it can be executed several times per second, and if it is walking, it can be executed about once every few seconds.

  When the map display process is executed, first, the main control unit 210 sets the range of the correction area DA according to the user's moving means and the attribute of the currently passing road (step S100). The correction area DA is an area for determining whether or not to correct the current position detected in step S110 described later to a position on the recommended route. The attribute of the road currently being traveled can be recognized by referring to the recommended route data stored in the RAM 212.

  FIG. 4 is an explanatory diagram illustrating the correction area DA corresponding to the moving means. FIG. 4 shows a correction area DA when the moving means is traveling on a general road by car, a correction area DA when the moving means is traveling by car on the highway, and a case where the moving means is walking. The correction area DA is shown. As shown in the drawing, the correction area DA is set to have a larger area as the moving means has a higher speed.

  For example, when the moving means is traveling on a general road by car, the correction area DA is moved in the horizontal direction across the recommended route RT from the corrected current position PP as a result of the previous execution of the map display process. Each of the regions has a range of 50 m and a length of 150 m forward along the recommended route RT, and the tip portion is set to a region formed in a triangular shape having an angle of 80 °. The apex of the tip is located on the recommended route RT.

  When the moving means is traveling on a highway by car, the correction area DA is an area of 100 m in the left-right direction across the recommended route RT from the previous current position PP, and 250 m ahead along the recommended route RT. And the tip portion is set in a region formed in a triangular shape having an angle of 120 °. The reason why the correction area DA is longer in the forward direction than when traveling on a general road is that the highway travels faster than the general road, and the expanse in the left-right direction is larger. In this case, it is difficult to move off the path, and thus it is possible to allow a large measurement error.

  When the moving means is walking, the correction area DA has areas of 30 m in the left-right direction across the recommended route RT from the previous current position PP, 90 m forward and 10 m rearward along the route, and the tip portion is The region is set to a triangular shape having an angle of 90 °. Also, the rear area is set to an arc-shaped area unlike the case where the moving means is a car. This is because the pedestrian does not always move forward and corrects the current position even when moving backward.

  When the correction area DA is set, the main control unit 210 detects the current position using the GPS receiver 201 (step S110). Then, it is determined whether or not the detected current position is within the correction area DA set in step S100 (step S120).

  If the detected current position is within the correction area DA (step S120: Yes), the main control unit 210 corrects the current position to the closest position on the recommended route (step S130). Specifically, the main control unit 210 draws a perpendicular line with respect to the recommended route RT from the detected current position, and corrects the current position at a position where the perpendicular line and the recommended route intersect. Note that if the detected current position is a position on the recommended route RT, the processing in step S130 may be skipped.

  FIG. 5 is an explanatory diagram showing a state where the current position detected in the correction area DA is corrected. FIG. 5 shows an example in which the current position NP is detected near the tip of the correction area DA. In step S130, the current position NP is moved in the direction indicated by the arrow in the drawing, and is corrected to a position on the recommended route RT.

  When the current position is corrected, the main control unit 210 acquires map data in a predetermined range (for example, 500 m square) including the corrected current position from the map server (step S140). When map data around the current position is buffered in the RAM 212, the main control unit 210 acquires map data corresponding to the current position from the buffered data. The range of the map data to be acquired can be adjusted according to the map display scale set by the user.

  When the map data is acquired, the main control unit 210 inputs recommended route data from the RAM 212 (step S150). This recommended route data is data received from the route search server 100 in the route search process shown in FIG.

  Subsequently, the main control unit 210 draws the map data in the vector format acquired in step S140 and the recommended route data in the vector format input in step S150 on the display panel 202 in a superimposed manner. Further, a mark indicating the corrected current position is superimposed thereon. Through the above processing, the corrected current position can be displayed on the map image.

  If it is determined in step S120 that the detected current position is outside the correction area DA (step S120: No), the main control unit 210 determines whether the detected current position is in the reroute area RA. (Step S170). The reroute area RA is an area outside the circumference located outside the correction area DA, as shown in FIG. Similarly to the correction area DA, the range of the reroute area RA is set in accordance with the user's moving means (and the attribute of the road being traveled).

  FIG. 4 shows an example of the reroute area RA corresponding to the moving means. As shown in FIG. 4, in this embodiment, for vehicles traveling on a general road, an area outside the circumference having a radius of 170 m from the previous current position PP corresponds to a vehicle traveling on a highway. In the case where the area outside the circumference with a radius of 300 m from the previous current position PP is walking, the area outside the circumference with a radius of 100 m from the previous current position PP is set as the reroute area RA. .

  When the current position NP is detected in the reroute area RA (step S170: Yes), the main control unit 210 further determines whether the current position NP has been detected in the reroute area RA ten times continuously (step S170). S180). This number of times may be varied according to the moving means of the user. When the current position NP is detected in the reroute area RA ten times in succession (step S180: Yes), the main control unit 210 performs a reroute process (step S190). The reroute process is a process for obtaining a recommended route again. The processing content of the reroute process is almost the same as the route search process shown in FIG. 2 except that the departure point is the current position NP detected in the reroute area RA.

  The starting point in the reroute process may be the last detected current position NP or the average position of the current positions detected ten times. Moreover, it is good also as a present position detected with the highest precision among ten times. The superiority or inferiority of accuracy can be determined, for example, according to the number of satellites captured when the current position is measured. In this case, it can be said that the greater the number of acquired satellites, the higher the accuracy. In addition, for example, by acquiring a parameter representing the level of accuracy from the GPS receiver 201, it is possible to determine whether the accuracy is superior or inferior.

  If the current position NP is not detected in the reroute area RA in step S170, or if it is not detected in the reroute area RA ten times continuously in step S180, the main control unit 210 performs the process. The process proceeds to step S140. That is, the correction of the current position NP in step S130 is skipped, and the detected current position is displayed on the map image as it is (steps S140 to S160). By doing so, the current position NP that has not been corrected is displayed on the display panel 202.

  If “No” is determined in step S170 or step S180, the current position NP is detected in an area that is neither the correction area DA nor the reroute area RA. Such an area is referred to as a dead area NA in this embodiment (see FIG. 5). That is, in the present embodiment, when the current position NP is detected in the insensitive area NA, the detected current position NP is displayed on the screen as it is without performing correction of the current position NP and rerouting processing. is there. In this way, when the current position is detected outside the correction area DA, it is possible to prevent the reroute process that requires communication with the route search server from being performed uniformly. As a result, it can suppress that the display response of a map image falls. In addition, when the current position NP is detected in the insensitive area NA, if the detected current position NP is displayed on the screen as it is, it can be suggested to the user that the route is off. Therefore, the user can smoothly return to the recommended route without waiting for the result of the reroute process. Since the user may intentionally pass a survey road that exists beside the recommended route, or may pass a shortcut or exit route in the vicinity of the recommended route, if the insensitive area NA is provided, the user frequently performs in such a situation. It is possible to suppress rerouting.

  According to the map display system of the present embodiment described above, the range of the correction area DA can be changed according to the user's moving means and the attribute of the road that is being passed. Therefore, it becomes possible to correct the current position according to the movement characteristics (average speed, rotatable radius, etc.) of the moving means.

  In the present embodiment, as shown in FIG. 4, the tip of the correction area DA is triangular. Therefore, the range in which the measurement error is allowed can be narrowed as the current position NP detected using the GPS receiver 201 moves further forward from the previous current position PP. This makes it possible to perform highly accurate correction.

  In the present embodiment, when the moving means is a car, the correction area DA is set only in the forward direction from the previous current position PP as shown in FIG. This is because, as long as the car is moving along the recommended route RT, basically, the car can be considered not to back. As described above, if the correction area DA is set only in the forward direction from the previous current position PP, the current position NP is detected on the map image when the current position NP is detected behind the previous current position PP due to a measurement error. It is possible to suppress the current position from moving backward on the recommended route RT. As a result, it is possible to suppress blurring in the displayed map image.

  On the other hand, when the moving means is walking, the pedestrian may move in the reverse direction or move left and right. Therefore, in this embodiment, as shown in FIG. 3, when the moving means is walking, the correction area DA is also present in the backward direction from the previous current position PP. Therefore, even when the pedestrian moves on the recommended route RT in the reverse direction, the current position can be correctly displayed.

  In this embodiment, when the current position is detected in the correction area DA, the current position is corrected on the recommended route, and when the current position is detected in the insensitive area NA, the detected current position is displayed as it is. To do. Further, when it is detected in the reroute area RA, a reroute process is performed. Therefore, a preferable map display can be performed according to the positional relationship between the detected current position and the recommended route RT.

D. Variations:
As mentioned above, although the Example of this invention was described, it cannot be overemphasized that this invention is not limited to such an Example, and can take a various structure in the range which does not deviate from the meaning. For example, the numerical values and shapes defining the correction area and the reroute range shown in FIG. 4 are examples, and other numerical values and shapes can be set as appropriate. In the above-described embodiment, the map data and the recommended route data are vector format data, but may be raster format data. In addition, the following modifications are possible.

(D1) Modification 1:
In the above embodiment, the main control unit 210 determines the user's moving means in response to an input from the user (see step S10 in FIG. 2). On the other hand, for example, the main control unit 210 may obtain an average speed from the sequentially detected current position history and the time interval of positioning, and may estimate the moving means of the user according to the average speed. For example, if the average speed is 20 km / h or more, it can be estimated as “car” if it is less than 10 km / h, “walk” if it is less than 10 km / h, and “bicycle” if it is 10-20 km / h.

(D2) Modification 2:
In the above embodiment, the range of the correction area DA is set according to the moving means of the user. In addition to this, the correction area DA may be adjusted according to the speed of the moving means. For example, the main control unit 210 obtains an average speed from the history of the current position sequentially detected and the time interval of positioning, and the length of the correction area DA in the front-rear direction can be increased as the average speed increases. In this way, for example, even if the moving means are the same “car”, different correction areas DA can be applied depending on the type of vehicle such as a light car or a sports car.

(D3) Modification 3:
FIG. 4 shows the correction area DA when the moving means is a car and a walk. However, besides these, for example, a correction area DA when the moving means is a bicycle or a train may be defined. Further, according to the example of FIG. 4, even when the moving means is on foot, the correction area DA having substantially the same shape as that of the car is set. However, in the case of walking, the correction area DA may be set to a circular or elliptical area. This is because a person does not necessarily move forward along the recommended route, and may detour in the left-right direction or may turn backward and move in the opposite direction to the recommended route.

(D4) Modification 4:
In the above embodiment, the range of the correction area DA is set according to the moving means. On the other hand, the range of the correction area DA may be varied according to the map display mode, for example. As the map display mode, there are a “route guidance mode” for guiding a route as in the above-described embodiment, and a “current position display mode” for displaying only the current position without guiding the route. For example, in the “route guidance mode”, a polygonal correction area DA can be set as shown in FIG. 4, and in the “current position display mode”, a circular correction area DA can be set. In the “current position display mode”, since there is no recommended route, it is unclear which direction the moving means travels. If there is no recommended route, a correction area DA along the route as shown in FIG. This is because it cannot be specified. As described above, if the correction area DA is made variable according to the map display mode, the convenience for the user can be further improved.

(D5) Modification 5:
In the above-described embodiment, the example in which the mobile phone 200 is applied as the map display device has been described. However, the map display device is not limited to the mobile phone 200, and a well-known car navigation system, PDA, personal computer, or the like can be applied.

(D6) Modification 6:
In the embodiment described above, the route search server 100 performs the route search. On the other hand, a storage device such as a flash memory in which a route database is recorded may be mounted on the mobile phone 200, and the mobile phone 200 itself may perform a route search by using the route database in the storage device. . Further, if map data is also included in the storage device, the map may be drawn using the map data.

(D7) Modification 7:
In the embodiment described above, the current position is determined by the GPS receiver 201 alone. However, the positioning of the current position may be performed using, for example, the GPS receiver 201 together with a vehicle speed sensor or an acceleration sensor.

1 is an explanatory diagram showing a schematic configuration of a map display system 10. FIG. It is a flowchart of a route search process. It is a flowchart of a map display process. It is explanatory drawing which illustrates correction area | region DA according to a moving means. It is explanatory drawing which shows a mode that the present position was correct | amended.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Map display system 100 ... Route search server 102 ... Communication part 104 ... Control part 105 ... Memory | storage device 106 ... Path | route database 150 ... Map server 152 ... Communication part 154 ... Control part 155 ... Memory | storage device 156 ... Map database 200 ... Mobile phone 201 ... GPS receiver 202 ... display panel 203 ... voice output unit 205 ... wireless communication circuit 206 ... command input unit 210 ... main control unit 211 ... CPU
212 ... RAM
213 ... ROM
220 ... Call control unit NA ... Dead zone DA ... Correction zone RA ... Reroute zone BS ... Base station RT ... Recommended route

Claims (14)

A map display device that displays a current position on a map,
A data acquisition unit for acquiring map data including information indicating a route to be traveled;
A moving means discriminating unit for discriminating the type of moving means of the user;
A position detector that sequentially detects the current position;
A correction area setting unit that sets a correction area that is a range for correcting the detected current position to a position on the route according to the type of the determined moving means;
A correction unit that corrects the current position to a position on the path only when the current position is detected within the set correction area;
A map display device comprising: a display unit that displays the corrected current position on a map image represented by the map data. The map display device according to claim 1,
The map display device, wherein the correction area setting unit sets, as the correction area, an area having a spread by a distance determined according to a type of the moving means in the left-right direction with the route as a center. The map display device according to claim 2,
When the moving means is a vehicle, the correction area setting unit uses the current position corrected last time as the rear end as the correction area, and a predetermined distance corresponding to the type of the moving means from the rear end. A map display device that sets an area with a tip in front. The map display device according to claim 2,
The correction area setting unit is a map display device that sets, as the correction area, an area that expands forward and backward by a predetermined distance from the current position corrected last time when the moving unit is walking. A map display device according to any one of claims 2 to 4,
The map display device, wherein the tip of the correction area is formed in a triangular shape having a vertex on the path. A map display device according to any one of claims 1 to 5,
The map display device, wherein the correction area setting unit sets the correction area according to the determined type of moving means and the attribute of the route. The map display device according to any one of claims 1 to 6,
The map display device, wherein the moving means determination unit determines a type of the moving means based on the sequentially detected current position history. A map display device according to any one of claims 1 to 7,
The map display device, wherein the correction area setting unit adjusts the correction area according to the determined speed of the moving means. The map display device according to any one of claims 1 to 8, further comprising:
A reroute area setting unit for setting a reroute area for determining whether to acquire a path different from the path to be traveled, which is an area outside the correction area, according to the determined moving means;
A map display device comprising: a reroute unit that acquires a new route that is different from the route and starts from the current position when the current position is detected in the set reroute region. . The map display device according to claim 9,
When the current position is detected in a dead area outside the correction area and inside the reroute area, the display unit directly detects the detected current position on the map image. Display on the map display device. The map display device according to any one of claims 1 to 10,
The data acquisition unit is a map display device that acquires the map data from a predetermined server by wireless communication. A map display method in which a computer displays a current position on a map,
Get map data that includes information that shows the route you should take,
Determine the type of user transportation,
Detect current position sequentially,
A correction area that is a range for correcting the detected current position to a position on the path is set according to the type of the determined moving means,
Only when the current position is detected within the set correction area, the current position is corrected to a position on the route,
A map display method for displaying the corrected current position on a map image represented by the map data. A computer program for displaying a current position on a map by a computer,
A data acquisition function for acquiring map data including information indicating a route to be traveled;
A moving means discriminating function for discriminating the moving means of the user;
A position detection function that sequentially detects the current position;
A correction area setting function for setting a correction area which is a range for correcting the detected current position to a position on the route according to the type of the determined moving means;
A correction function for correcting the current position to a position on the route only when the current position is detected within the set correction area;
A computer program that causes a computer to realize a display function of displaying the corrected current position on a map image represented by the map data.   A computer-readable recording medium on which the computer program according to claim 13 is recorded.

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