JP2011169631A - Computer program and method for processing map data executed by information processing apparatus, and map display device - Google Patents

Abstract

A computer program that can quickly detect the direction in which an information processing apparatus travels and can reduce the influence of external interference of an electronic compass.
A step of detecting a current position of the information processing apparatus 1 at each time at a plurality of different times, a step of storing position data indicating the current position of the information processing apparatus at each detected time, and And calculating the second direction in which the information processing apparatus is proceeding based on the position data being displayed, and displaying the map image based on the map data on the display, reflecting the second direction, and the map image When the step of displaying the current position of the information processing device and the step of determining whether or not a predetermined display switching condition is satisfied are realized, and the determination step determines that the display switching condition is satisfied Switches the map image displayed on the display reflecting the second orientation to a display reflecting the first orientation.
[Selection] Figure 2

Description

  The present invention relates to an information processing apparatus, and more particularly to a computer program, a method, and a map display apparatus for processing map data executed by a versatile portable information processing apparatus.

  Conventionally, as a map display device, for example, a car navigation device, a PND (Personal / Portable Navigation Device), and the like are known.

In dedicated map display devices such as car navigation devices and PNDs, GPS (Global
Not only the position is detected by Positioning System), but also the acceleration by the acceleration sensor, the rotation angle of the vehicle by the gyrocompass, etc. are detected. As a result, the vehicle position is displayed on the map as accurately as possible, such as link matching that matches the current position of the vehicle on the road, and heading-up display that displays the map so that the traveling direction of the vehicle is upward. The direction in which the vehicle travels was quickly reflected on the map.

  On the other hand, in recent years, even general-purpose information processing apparatuses typified by mobile phones, there are models that can realize a computer program for processing map data. These models have a position detection function represented by a GPS function. However, since these information processing apparatuses are not dedicated map display apparatuses as described above, there are many simple information apparatuses that are not equipped with an autonomous sensor such as an acceleration sensor and a gyrocompass. In such a general-purpose information processing apparatus, the direction in which the information processing apparatus travels must also be detected based on the position information. Therefore, in this case, the traveling direction is calculated from a plurality of detected positions and the time at which each position is detected. For this reason, it took a very long time to reflect the correct orientation on the map.

  In order to quickly detect the correct orientation for the above problem, the inventor tried to apply the orientation detected by the electronic compass in the computer program for processing the map data realized by the general-purpose information processing device. Tried. Some general-purpose information processing apparatuses such as cellular phones are already equipped with an electronic compass. For this reason, it is very easy to apply the direction detected by the electronic compass to the map display program. An electronic compass is a device that incorporates a geomagnetic sensor (orientation sensor) using a semiconductor, detects the north-south geomagnetic signal generated by the earth, and calculates the direction (azimuth) of the electronic compass from the geomagnetic signal. It has a function. An electronic compass includes one that detects an azimuth from two axes X and Y and one that detects an azimuth from three axes X, Y, and Z.

  However, the electronic compass is susceptible to external interference and is very unstable. In particular, the accuracy of the direction detected by the electronic compass is very poor near obstacles such as iron bridges and large trucks. Therefore, when the position based on the GPS reception signal and the direction based on the electronic compass are simply used together, every time the information processing device passes by the obstacle, there is a problem that the direction of the map on the display changes drastically. Occurred.

  An object of the present invention is to provide a computer program, a method, and a map display device that can quickly detect the direction in which an information processing device travels and can reduce the influence of external interference of an electronic compass.

  A computer program according to one embodiment of the present invention comprises an electronic compass for detecting a first orientation, a display, and map data storage means for storing map data for displaying a map image on the display. A computer program for processing map data executed by an information processing apparatus, and when executed by the information processing apparatus, detects a current position of the information processing apparatus at each time at a plurality of different times A step of storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit, and based on the position data stored in the position data unit Calculating the second direction in which the information processing apparatus is traveling; and the second direction A display control step of reflecting a second orientation calculated in the calculation step, displaying a map image based on the map data on a display, and displaying a current position of the information processing device on the map image; And a step of determining whether or not the display switching condition is satisfied, and when the determination step determines that the display switching condition is satisfied, the display control step includes the second orientation. The map image reflected on the display is switched to a display reflecting the first orientation.

  In a preferred embodiment, the step of calculating the moving speed of the information processing device is further realized based on the position data stored in the position data storage means, and the display switching condition is the movement of the information processing device. Whether or not the speed is equal to or less than a threshold value, and if the determination step determines that the moving speed is equal to or less than the threshold value, the display control step displays the second orientation on the display. The map image displayed heading up based on the above may be switched to the heading up display based on the first orientation.

  In a preferred embodiment, the display switching condition is whether or not the current position of the information processing apparatus is on an expressway, and the determination step determines that the current position is not on an expressway. In this case, the display control step may switch a map image displayed on the display based on the second direction to a heading-up display based on the first direction.

  In a preferred embodiment, the condition is whether or not the second orientation of the information processing device has changed by a threshold value or more within a predetermined time, and the information processing within the predetermined time is determined by the determination step. When it is determined that the second orientation of the device has changed by a threshold value or more, the display control step displays a map image displayed heading up on the display based on the second orientation, You may switch to the heading-up display based on a 1st direction.

  In a preferred embodiment, a step of searching for a route from a starting point to a destination of the information processing device, a step of extracting a bending point where the route is bent at a predetermined angle or more in the route searched by the route searching step, The display switching condition is whether or not the current position of the moving information processing apparatus is around a bending point, and the determination step determines whether the current position of the information processing apparatus is determined by the extraction step. When it is determined that the area is around the extracted bending point, the display control step displays the map image displayed heading up on the display based on the second direction, with the first direction You may switch to the heading-up display based on.

  A computer program according to another embodiment of the present invention includes an electronic compass for detecting a first orientation, a display, and map data storage means in which map data for displaying a map image on the display is stored. A computer program for processing map data executed by an information processing apparatus, and when executed by the information processing apparatus, detects a current position of the information processing apparatus at each time at a plurality of different times A step of storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit, and based on the position data stored in the position data unit Calculating a second direction in which the information processing apparatus is traveling; and the second direction Reflecting the second orientation calculated in the output step, displaying a map image based on the map data on a display, displaying the current position of the information processing apparatus on the map image, and the position detecting step Predicting the current position of the information processing apparatus based on the position data and the moving speed before the first time when the current position cannot be detected continuously for a predetermined time after the first time. Determining whether the amount of change between the first orientation detected by the electronic compass before the first time and the first orientation detected by the electronic compass after the first time is equal to or less than a predetermined amount; And the determination step detects the first compass detected by the electronic compass before the first time and the electronic compass detected after the first time. When it is determined that the amount of change from one direction is equal to or less than a predetermined amount, the display control step displays the current position of the information processing apparatus predicted by the prediction step on a map image of the display It is characterized by making it.

  A computer program according to still another embodiment of the present invention includes an electronic compass for detecting a first orientation, a display, and map data storage means for storing map data for displaying a map image on the display. A computer program for processing map data executed by an information processing device provided, and when executed by the information processing device, detects a current position of the information processing device at each time at a plurality of different times A step of storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit, a step of performing link matching, and the link matching step A first link that matches the current position at time 1 and the When the matching step is not continuous with the second link that matches the current position at the second time after the first time, the electrons are between the first time and the second time. Determining whether the matching for the second link is correct based on the direction detected by the compass; correcting the result of link matching by the link matching step based on the determination result of the correctness determination step; And displaying a map image based on the map data on a display and displaying a current position of the information processing apparatus on the map image based on the processing results of the link matching step and the link matching correction step. It is characterized by that.

  A map display device according to an embodiment of the present invention includes a display, an electronic compass for detecting a first orientation, means for storing map data for displaying a map image on the display, and a plurality of different times. A position detection means for detecting a current position of the map display device at each time; a storage means for storing position data indicating a current position of the map display device at each time detected by the detection means; Based on the position data stored in the means, the second azimuth calculating means for calculating the second azimuth in which the map display device is traveling, and the second azimuth calculated by the second azimuth calculating means are reflected. Display control for displaying a map image based on the map data on a display and displaying a current position of the map display device on the map image. And a determination unit that determines whether or not a predetermined display switching condition is satisfied, and when the determination unit determines that the display switching condition is satisfied, the display control unit includes: The map image displayed on the display reflecting the second azimuth is switched to a display reflecting the first azimuth.

1 is a conceptual diagram of a map display device in which a computer program according to a preferred embodiment of the present invention is installed. It is a block diagram of the map display apparatus of FIG. It is a figure which shows an example of the data structure in position DB of FIG. It is a figure which shows an example of the data structure in 1st azimuth | direction DB of FIG. It is a flowchart which shows operation | movement of the map display apparatus 1 when the 1st display switching condition is set. It is a flowchart which shows operation | movement of the map display apparatus 1 when a 2nd display switching condition is set. It is a flowchart which shows operation | movement of the map display apparatus 1 when the 3rd display switching condition is set. It is a flowchart which shows operation | movement of the map display apparatus 1 when the 4th display switching condition is set. It is explanatory drawing explaining a position prediction function. It is a flowchart which shows operation | movement of the map display apparatus 1 when the 5th display switching condition is set. It is explanatory drawing explaining a link matching and a link matching correction function. It is a figure which shows an example of the data structure in the matching memory | storage part of FIG. It is a flowchart which shows operation | movement of the map display apparatus 1 when the 6th display switching condition is set.

  Hereinafter, a map display device realized in a mobile phone according to a preferred embodiment of the present invention will be described. The map display device 1 according to the present embodiment is realized by installing a predetermined computer program on a mobile phone. In order to realize the map display device 1, not only a mobile phone but also other versatile information processing devices may be used. In this embodiment, a car navigation program is installed in the mobile phone. However, the installed program may be, for example, a pedestrian navigation program or the like, or may be a program that simply detects the current position and displays it on a map, instead of the navigation program.

  FIG. 1 is a conceptual diagram of a map display device 1 according to the present embodiment. For example, the map display device 1 may include a receiver 6 that receives a GPS signal from the GPS satellite 2. For example, the map display device 1 may be detachably fixed to the vehicle 3 by providing a dedicated folder on the instrument panel of the vehicle 3. Further, for example, the map display device 1 may be held by a user (for example, a passenger in the front passenger seat).

  FIG. 2 is a configuration diagram of the map display device 1.

  The map display device 1 includes a map data processing unit 4, a display 5, a receiver 6, an electronic compass 7, an input unit 8, and a map information database (hereinafter referred to as map information DB) 9. The map data processing unit 4 is realized by executing a predetermined program using a processor and a memory (not shown) of the mobile phone.

  The receiver 6 receives GPS signals from a plurality of GPS satellites 2. The receiver 6 notifies the arithmetic processing unit 11 of the map data processing unit 4 of the received GPS signal.

  The electronic compass 7 detects the direction. For example, in FIG. 1, the electronic compass 7 may detect which direction the upper side of the map display device 1 is facing. Hereinafter, the direction detected by the electronic compass 7 is referred to as a first direction. For example, the electronic compass 7 notifies the determination unit 15 of the map data processing unit 4 described later of the detected first orientation. The electronic compass also stores the detected first orientation together with the detection time in a first orientation database (hereinafter referred to as a first orientation DB) 20 of the map data processing unit 4 described later.

  The display 5 is a well-known display 5 provided in the map display device 1 and includes a form such as a touch panel that can operate an icon or the like on the display 5 with a finger or the like. The display 5 displays a map image, the current position of the map display device 1 and the like by a display control unit 13 described later.

  A destination and a starting point are input to the input unit 8 by the user. The input to the input unit 8 is performed by an operation using a button of the map display device 1 or an operation from the display 5 in a touch panel form. Information input from the input unit 8 is transmitted to the route search unit 16 of the map data processing unit 4 described later.

  The map information DB 9 stores map data for displaying a map image on the display 5. In the map information DB 9, for example, map data acquired through a network may be temporarily stored, or map data of a predetermined area may be always stored, for example, a Japanese road map.

  The map data processing unit 4 includes an acquisition unit 10, an arithmetic processing unit 11, a position database (hereinafter referred to as position DB) 12, a display control unit 13, a condition storage unit 14, and a determination unit 15. The map data processing unit 4 also includes a route search unit 16, an extraction unit 17, a position prediction unit 18, a matching processing unit 19, a first orientation DB 20, a movement angle calculation unit 21, a monitoring unit 22, and a matching storage unit 23. Good. Each component in the map data processing unit 4 will be described below.

  In order to display a map image on the display 5, the acquisition unit 10 acquires map data around the current position from the map information DB 9 and transmits the map data to the display control unit 13. Since the acquisition unit 10 acquires map data around the current position from the map information DB 9, the acquisition unit 10 may acquire position data 32 (see FIG. 3) at the current time 31 from the position DB 12. In this case, for example, the acquisition unit 10 may acquire peripheral map data centered on the current position. In addition, when a map image around the current position is displayed on the display 5, the acquisition unit 10 acquires only the difference between the map data of the displayed image and the surrounding map data centered on the current position. May be.

  FIG. 3 is a diagram showing a position data table 30 which is an example of a data structure in the position DB 12. The position data table 30 has, as its data structure, a time 31, latitude data 32 a and longitude data 32 b as position data 32 of the map display device 1 at that time, a moving speed 33 of the map display device 1, and a map display device. One second orientation 34. Details will be described later.

The arithmetic processing unit 11 detects the current position of the map display device 1 at each time at a plurality of different times. For example, the arithmetic processing unit 11 may detect the current position of the map display device 1 from the GPS signal notified from the receiver 6. The current position is, for example, position data 32 including current latitude data 32a and longitude data 32b of the map display device 1 calculated from GPS signals.
The arithmetic processing unit 11 also stores position data 32 indicating the current position of the map display device 1 at each time in the position DB 12. For example, the arithmetic processing unit 11 may store the detected position data 32 in the position DB 12 together with the time 31 when the position data 32 is detected.

  The arithmetic processing unit 11 calculates the moving speed 33 of the map display device 1 based on the position data 32 stored in the position DB 12. The arithmetic processing unit 11 may calculate the moving speed 33 of the map display device 1 with reference to the position DB 12 from the plurality of position data 32 and each detection time 31 of the position data 32. For example, the arithmetic processing unit 11 calculates the moving speed 33 based on the position data 32 and the detection time 31 at a certain time, and one or more position data 32 and the detection time 31 detected before that time. . For example, the arithmetic processing unit 11 stores the calculated moving speed 33 in the position DB 12. In FIG. 3, the arithmetic processing unit 11 includes position data 32 when the detection time 31 is “17:00:00” and position data 32 when the detection time 31 is “17:00:02”. Thus, the moving speed 33 during this period is calculated, and the calculated moving speed 33 “30 km / h” is stored as the moving speed 33 when the time 31 is “17:00:02”.

  The arithmetic processing unit 11 calculates the direction in which the map display device 1 is traveling based on the position data 32 stored in the position DB 12. The arithmetic processing unit 11 may calculate the azimuth of the map display device 1 by referring to the position DB 12 and using the plurality of position data 32 and each detection time 31 of the position data 32. Hereinafter, the direction calculated by the arithmetic processing unit 11 is referred to as a second direction 34. For example, the arithmetic processing unit 11 calculates the second orientation 34 based on the position data 32 at a certain time and the detection time 31 thereof, and the one or more position data 32 and the detection time 31 detected before that time. . The second azimuth 34 may be calculated at 360 degrees in all directions, for example, with north as a reference (0 degree). For example, the arithmetic processing unit 11 stores the calculated second orientation 34 of the map display device 1 in the position DB 12. In FIG. 3, the arithmetic processing unit 11 includes position data 32 when the detection time 31 is “17:00:00” and position data 32 when the detection time 31 is “17:00:02”. The second azimuth 34 is calculated from the second azimuth 34, and the calculated second azimuth “180 °” is stored as the second azimuth 34 when the time 31 is “17:00:02”.

  The first orientation DB 20 stores the first orientation notified from the electronic compass 7 together with the detection time of the first orientation. FIG. 4 is a first orientation table 40 as an example of the data structure of the first orientation DB 20. The first orientation table 40 has, as its data structure, a first orientation 44 detected by the electronic compass 7 and a time 41 when the first orientation is detected. The second azimuth 44 may be calculated at 360 degrees in all directions, for example, with north as a reference (0 degree).

The display control unit 13 causes the display 5 to display a map image based on the map data and reflect the current orientation of the map display device 1 on the map image, reflecting the second orientation calculated by the arithmetic processing unit 11. For example, the display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10. Further, for example, the display control unit 13 acquires the position data 32 at the current time 31 from the position DB 12 and sequentially displays the current position of the map display device 1 on the map image. Thereby, the locus of movement of the map display device 1 may be displayed on the map image. The position data of the current position acquired for the display control unit 13 to display the map image may be the position data at the latest time notified from the arithmetic processing unit 11.
The display control unit 13 also reflects the second orientation 34 calculated by the arithmetic processing unit 11 on the map image. The reflection of the second orientation 34 on the map image is performed by, for example, a heading-up display based on the second orientation 34.

  The display control unit 13 also displays a map image reflected on the display 5 with the second orientation reflected on the display 5 based on the determination result of the determination unit 15 described later, reflecting the first orientation detected by the electronic compass. Switch to. For example, when the determination result that the predetermined switching display condition is satisfied is notified from the determination unit 15, the display control unit 13 acquires the current or latest first direction 44 from the first direction DB 20, The heading up display based on this is switched.

  The condition storage unit 14 stores display switching conditions. The display switching condition is, for example, a condition when the determination unit 15 determines. The display switching condition may be a condition based on a moving speed or a condition based on a change in moving direction. For example, the display switching condition is “whether or not the moving speed is equal to or less than a threshold value”, “whether or not the current position is on a highway”, and “the direction in which the map display device 1 travels within a predetermined time is a threshold value” It may be set such as “whether it has changed or not”, “whether the current position is around the bending point”, or the like. The conditions stored in the condition storage unit 14 may be registered in advance or may be registered every time it is used. Moreover, you may select suitably in the case of use from the registered conditions.

  The determination unit 15 determines whether the display switching condition is satisfied. For example, the determination unit 15 determines whether or not one or more conditions in the condition storage unit 14 are satisfied. At this time, the determination unit 15 may acquire necessary data or the like according to the display switching condition. For example, when determining whether or not the condition “whether or not the moving speed is equal to or less than the threshold” is satisfied, the determining unit 15 refers to the position data table 30 in the position DB 12 and determines the current moving speed. 33 is acquired. Then, the determination unit 15 determines whether or not the current moving speed 33 is equal to or lower than the hourly speed (or minute speed or second speed) set as the threshold value. The determination unit 15 notifies the display control unit 13 of the determination result.

  When the determination unit 15 determines that the display switching condition is satisfied, the display control unit 13 reflects the second orientation 34 calculated by the arithmetic processing unit 11 and is displayed on the display 5. Is switched to a display reflecting the first orientation detected by the electronic compass 7. For example, when the determination unit 15 receives a notification that “the condition is satisfied”, the display control unit 13 sets the map image displayed in the heading-up based on the second direction 34 to the first direction. You may make it switch to the heading-up display based on.

  Next, the operation of the map display device 1 according to this embodiment will be described.

  In the present embodiment, by executing a car navigation program, a map display function for displaying a map around the current position on the display 5, a current position display function for displaying the current position on the map displayed on the display 5, The map display device 1 has main functions such as a link matching function that corrects a deviation of the detected current position, a route search function that searches for a route from the departure point to the destination, and a navigation function that performs navigation along the searched route. Realized. In addition to this, various functions such as a heading-up function, a position prediction function, and a link matching correction function may be realized by the map display device 1 by executing a car navigation program.

  Below, operation | movement of the map display apparatus 1 which concerns on this embodiment is demonstrated for every various function called a heading-up function, a position prediction function, and a link matching correction function.

  First, the map display device 1 having a heading-up function will be described below. In the following description, each operation will be described with reference to the flowcharts of FIGS. 5 to 8 for each display switching condition determined by the determination unit 15.

  In general, it is assumed that the moving speed of the vehicle 3 decreases to a predetermined value or less before changing direction, such as in the vicinity of an intersection. FIG. 5 is a flowchart showing the operation of the map display apparatus 1 when the condition “whether or not the speed of the map display apparatus 1 falls below a threshold value” is set as the display switching condition based on this assumption. is there. In this example, the threshold is 5 km / h, but the threshold may be set in any manner.

  The flowchart of FIG. 5 is performed at a predetermined interval from when the map display device 1 is activated until it is terminated.

  The acquisition unit 10 acquires the surrounding map data of the current position from the map information DB 9 and transmits it to the display control unit 13. The display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10 (step S101).

  The display control unit 13 refers to the position DB 12 and displays the current position on the map image of the display 5 based on the current (latest) position data 32 (step S102).

  The determination unit 15 acquires the current (latest) moving speed 33 from the position DB 12 (step S103).

  The determination unit 15 extracts the switching display condition in the condition storage unit 14. Here, for example, a condition that “the speed is 5 km / h or less” is extracted. Then, the determination unit 15 determines whether or not the current (latest) moving speed 33 acquired from the position DB 12 in step S103 is 5 km / h or less (step S104).

  When the current (latest) moving speed 33 is 5 km / h or less, that is, when the condition is satisfied (step S104: Yes), the determination unit 15 notifies the display control unit 13 of the determination result. .

  Upon receiving the notification, the display control unit 13 acquires the first azimuth 44 at the current (latest) time 41 from the first azimuth DB 20 and performs heading-up based on the first azimuth 44. (Step S105).

  On the other hand, when the current (latest) moving speed 33 is faster than 5 km / h, that is, when the condition is not satisfied (step S104: No), the determination unit 15 notifies the display control unit 13 of the determination result. To do.

Upon receiving the notification, the display control unit 13 acquires the current (latest) second direction 34 in the position DB 12, and performs heading-up based on this (step S106).
By performing the above operation, the map display device 1 is able to increase the heading by applying the first direction 44 detected by the electronic compass 7 only when the moving speed 33 is a predetermined value (5 km / h in this example) or less. Display can be performed. When the moving speed 33 of the map display device 1 is less than or equal to a predetermined value, the map display device 1 is likely to change direction, such as when the vehicle has entered an intersection as described above. For this reason, it is possible to display the heading up by efficiently applying the first direction by the electronic compass having a large amount of external interference.

  Next, the case where the display switching condition “whether the current position of the map display device 1 is not on the expressway” is set for the map display device 1 having the heading-up function will be described. In addition, about the said component, when the function is added, it adds to the following.

  The determination unit 15 acquires map data around the current position from the map information DB 9 and determines whether a road on the map is a highway or a road other than a highway such as a general road based on the acquired map data. Identify. The determination unit 15 determines whether the current position based on the position data 32 is on the highway.

  FIG. 6 is a flowchart showing the operation of the map display device 1 when the condition “whether the current position of the map display device 1 is not on the expressway” is set as the display switching condition.

  The flowchart of FIG. 6 is performed at a predetermined interval from when the map display device 1 is activated until it is terminated.

  The acquisition unit 10 acquires the surrounding map data of the current position from the map information DB 9 and transmits it to the display control unit 13. The display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10 (step S201).

  The display control unit 13 refers to the position DB 12 and displays the current position on the map image of the display 5 based on the current (latest) position data 32 (step S202).

  For example, the determination unit 15 acquires map data around the current position from the map information DB 9 (step S203).

  Further, the determination unit 15 acquires the current (latest) position data 32 from the position DB 12 (step S204).

  Further, the determination unit 15 extracts the switching display condition in the condition storage unit 14. The switching display condition is “whether the current position of the map display device 1 is not on the expressway” as described above. Then, the determination unit 15 compares the map data acquired in step S204 with the current (latest) position data 32 acquired in step S204, and determines whether or not the current position is on the expressway (step). S205).

  When the current position is not on the expressway, that is, when the condition is satisfied (step S205: Yes), the determination unit 15 notifies the display control unit 13 of the determination result.

  Upon receiving the notification, the display control unit 13 acquires the first azimuth 44 at the current (latest) time 41 from the first azimuth DB 20 and performs heading-up based on the first azimuth 44. (Step S206).

  On the other hand, when the current position is on the expressway, that is, when the condition is not satisfied (step S205: No), the determination unit 15 notifies the display control unit 13 of the determination result.

Upon receiving the notification, the display control unit 13 acquires the current second orientation 34 in the position DB 12, and performs heading-up based on this (step S207).
By performing the above operation, the map display device 1 is able to improve the heading by applying the first direction 44 detected by the electronic compass 7 only when the current position is other than the highway (such as on a general road). Display can be performed. The map display device 1 is more likely to change direction when traveling on other general roads than when traveling on an expressway. For this reason, it is possible to display the heading up by efficiently applying the first direction by the electronic compass having a large amount of external interference.

  Next, for the map display device 1 having a heading-up function, a case will be described in which a display switching condition “whether the movement angle of the map display device 1 has changed by a threshold value or more within a predetermined time” is set. In addition, about the above-mentioned component, when the function is added, it adds to the following.

  The movement angle calculation unit 21 refers to the first direction DB 20 and calculates the movement angle of the map display device 1 based on the plurality of first directions 44. For example, the movement angle calculation unit 21 may calculate the difference between the angles of the map display device 1 based on the two most recent first orientations 44 in the first DB 20, or may include a plurality of first orientations retroactive to the nearest. And the plurality of first orientations before that may be compared to detect the movement angle of the map display device 1. For example, the movement angle calculation unit 21 notifies the determination unit 15 of the calculated movement angle of the map display device 1.

  FIG. 7 is an example showing the operation of the map display device 1 when the condition “whether the movement angle of the map display device 1 has changed by a threshold value or more within a predetermined time” is set as the display switching condition. . In this example, the predetermined time is 3 seconds and the threshold is 45 degrees, but the time and threshold may be set in any manner.

  The flowchart in FIG. 7 is performed at predetermined intervals from when the map display device 1 is activated until it is terminated.

  The acquisition unit 10 acquires the surrounding map data of the current position from the map information DB 9 and transmits it to the display control unit 13. The display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10 (step S301).

  The display control unit 13 refers to the position DB 12 and displays the current position on the map image of the display 5 based on the current (latest) position data 32 (step S302).

  For example, the movement angle calculation unit 21 refers to the first azimuth DB 20 to acquire the first azimuth 44 of the current (latest) time 41 and one or a plurality of times whose difference from the current time 41 is within 3 seconds. The first orientation 44 is acquired. Then, the movement angle calculation unit 21 calculates how much the other first azimuth 44 has changed with the first azimuth 44 at the current time 41 as a reference (step S303). The movement angle calculation unit 21 notifies the determination unit 15 of the calculated movement angle.

  The determination unit 15 extracts the switching display condition in the condition storage unit 14. As described above, the switching display condition is “whether the movement angle of the map display device 1 has changed by 45 degrees or more within 3 seconds”. And the determination part 15 determines whether the angle notified from the movement angle calculation part 21 is 45 degrees or more (step S304).

  When the movement angle changes by 45 degrees or more, that is, when the condition is satisfied (step S304: Yes), the determination unit 15 notifies the display control unit 13 of the determination result.

  Upon receiving the notification, the display control unit 13 acquires the first azimuth 44 at the current (latest) time 41 from the first azimuth DB 20 and performs heading-up based on the first azimuth 44. (Step S305).

  On the other hand, when the movement angle does not change by 45 degrees or more, that is, when the condition is not satisfied (step S304: No), the determination unit 15 notifies the display control unit 13 of the determination result.

Upon receiving the notification, the display control unit 13 acquires the current (latest) second direction 34 in the position DB 12, and performs heading-up based on the second direction 34 (step S306).
By performing the above operation, the map display device 1 can perform a heading-up display by applying the first direction 44 detected by the electronic compass 7 only when the movement angle within a predetermined time changes by a threshold value or more. . When the movement angle of the map display device 1 within a predetermined time changes by more than a threshold, the map display device 1 is highly likely to change direction when entering an intersection. Thereby, it is possible to display the heading-up display by efficiently applying the first direction by the electronic compass with a lot of external interference.

  Next, the case where the display switching condition “whether or not the current position is around the bending point extracted by the extraction unit 17” is set for the map display device 1 having the heading-up function will be described. In addition, about the above-mentioned component, when the function is added, it adds to the following.

  The route search unit 16 searches for a route from the departure point to the destination of the map display device 1. The departure point may be the current position, for example, or may be a start point set by the user, for example. The route search unit 16 notifies the display control unit 13 and the extraction unit 17 of the searched route.

  When the route is notified from the route search unit 16, the display control unit 13 reflects the notified route on the map image on the display 5.

  The extraction unit 17 receives the route notified by the route search unit 16. The extraction unit 17 extracts position data of a bending point where the route is bent by a predetermined angle or more in the received route. For example, when there are bending points in the route from the start point (or current location) searched by the route search unit 16 to the destination, the extraction unit 17 extracts the bending points. The bending point is a point where the route bends at a predetermined angle or more, such as an intersection or a curved road. For example, the bending point may be a node when the angle between the links that continue through the nodes in the map data is greater than or equal to a predetermined angle when straight ahead is 0 degree. The angle of the bending point may be set in advance. The extracted bending point position data is notified to the determination unit 15.

  The determination unit 15 determines whether or not the display switching condition is satisfied. The display switching condition is “whether or not the current position is around the bending point extracted by the extraction unit 17”. When the display switching condition is satisfied, the determination unit 15 notifies the display control unit 13 to that effect. Upon receiving the notification, the display control unit 13 switches the map image displayed on the display 5 to reflect the second traveling direction to a display reflecting the direction detected by the electronic compass.

  FIG. 8 shows an example of the operation of the map display device 1 when the condition “whether the current position is around the bending point extracted by the extraction unit 17” is set as the display switching condition.

  For example, the route search unit 16 searches for a route from the current position to the destination based on the destination input by the user to the input unit and the position data 32 of the current position. The route search unit 16 notifies the display control unit 13 and the extraction unit 17 of the searched route. The display control unit 13 displays the route notified from the route search unit 16 together with the map image (step S401).

  The extraction unit 17 receives a route from the route search unit 16. The extraction unit 17 extracts the position data of the bending point in the received route and notifies the determination unit 15 (step S402).

  The acquisition unit 10 acquires the surrounding map data of the current position from the map information DB 9 and transmits it to the display control unit 13. The display control unit 13 displays a map image around the current position on the display based on the map data received from the acquisition unit 10 (step S403).

  The display control unit 13 acquires the position data 32 of the current position from the position DB 12 and displays it on the map image on the display 5 (step S404).

  The determination unit 15 determines whether or not the current position based on the position data 32 acquired in step S404 is around the bending point based on the position data notified to the determination unit 15 in step S402 (step S405).

  When the current position is around the bending point, that is, when the condition is satisfied (step S405: Yes), the determination unit 15 notifies the display control unit 13 of the determination result.

  Upon receiving the notification, the display control unit 13 acquires the first azimuth 44 at the current (latest) time 41 from the first traveling azimuth DB 20 and performs heading-up based on this. (Step S406).

  On the other hand, when the current position is not around the bending point, that is, when the condition is not satisfied (step S405: No), the determination unit 15 notifies the display control unit 13 of the determination result.

  Upon receiving the notification, the display control unit 13 acquires the current second orientation 34 in the position DB 12, and performs heading-up based on the second orientation 34 (step S407).

After performing heading-up in step S406 or step S407, the determination unit 15 determines whether or not the destination has been reached (step S408). If the destination has been reached (step S408: Yes), the process ends. On the other hand, if the destination has not yet been reached, the process returns to step S403.
By performing the above operation, the map display device 1 displays a heading-up display by applying the first azimuth 44 detected by the electronic compass 7 only when the current position is around the bending point in the route searched in advance. Can be done. At the bending point, the map display device 1 is very likely to change direction. Thereby, it is possible to display the heading-up display by efficiently applying the first direction by the electronic compass with a lot of external interference.

  In the map display device 1 having the heading-up function described above, usually, a predetermined display switching condition is satisfied in the map image displayed on the display 5 by reflecting the second orientation calculated by the arithmetic processing unit 11. The first direction detected by the electronic compass 7 is reflected only when it is performed. Thereby, when a predetermined display switching condition is satisfied, the direction can be reflected quickly, and the influence of external interference of the electronic compass can be reduced.

  Next, the map display device 1 having a position prediction function will be described below.

  The position prediction function is a function realized when the current position of the map display device 1 cannot be detected for a certain period of time. For example, as shown in FIG. 9, this function is realized when the map display device 1 is moving and passing through the tunnel and cannot receive a GPS signal from the GPS satellite 2 through the tunnel. In the illustrated example, the position data p1 indicated by the solid line is detected, but the position data p2 indicated by the broken line in the tunnel is not detected. In such a case, if the traveling direction is constant as in the illustrated example, the map display device 1 should follow a trajectory as indicated by the position data p2. Therefore, when the current position is not detected for a certain period of time, predicted position data predicted from the position data 32 and the moving speed 33 at the time of detection is calculated, and the moving angle based on the first azimuth 44 is within a predetermined value. For example, the predicted position data is displayed on the map image.

  For the map display device 1 having a position display function, “when the current position cannot be detected continuously after the first time, the first direction detected by the electronic compass before the first time, and the first A case will be described in which the display switching condition “whether the amount of change from the first orientation detected by the electronic compass after the time is equal to or less than a predetermined amount” is set. In addition, about the above-mentioned component, when the function is added, it adds to the following.

  The monitoring unit 22 monitors the position data table 30 in the position DB 12. When the position data table 30 is not updated for a predetermined time, the monitoring unit 22 notifies the determination unit 15 together with the updated last time 31.

  The determination unit 15 extracts the switching display condition in the condition storage unit 14. Here, “when the current position cannot be detected continuously after the first time, the first direction detected by the electronic compass before the first time and the first direction detected by the electronic compass after the first time” The switching display condition “whether or not the amount of change from one direction is a predetermined amount or less” is extracted.

  Upon receiving a notification from the monitoring unit 22 that the position data table 30 is not updated for a predetermined time and the last updated time 31 from the monitoring unit 22, the determination unit 15 acquires necessary data and performs the above determination. For example, after receiving the notification from the monitoring unit 22, the determination unit 15 refers to the first azimuth DB 20 and the current (latest) first azimuth and the time 31 when the position data table 30 was last updated. A first azimuth (hereinafter referred to as final time first azimuth) at a time that is before and closest to the time 31 is acquired, and a change amount of the first azimuth between the two points is calculated. Note that the amount of change need not be calculated from the two points of the current first direction and the first time of the final time, but may be calculated from the first direction between a plurality of points between them.

  The determination unit 15 determines whether or not the calculated change amount is equal to or less than a predetermined amount.

  When the arithmetic processing unit 11 cannot continuously detect the current position after the first time, the position predicting unit 18 uses the map display device 1 based on the position data 32 and the moving speed 33 before the first time. Predict the current position of. The position prediction unit 18 receives the notification from the determination unit 15. The position prediction unit 18 that has received the notification from the monitoring unit 22 calculates a predicted position predicted as the current position based on each data in the position data table 30 in the position DB 12. For example, the position prediction unit 18 predicts the map display device 1 from one or a plurality of position data 32 and the movement speed 33 of the latest time 31 (the last update time and the time near it) in the position data table 30. Calculate the position. The position prediction unit 18 notifies the acquired prediction position to the acquisition unit 10 and the display control unit 13.

  FIG. 10 shows that “when the current position cannot be detected continuously after the first time, the first direction detected by the electronic compass before the first time and the electronic compass detected after the first time. It is an example which shows operation | movement of the map display apparatus 1 when the display switching condition "whether the variation | change_quantity with a 1st azimuth is below a predetermined amount" is set. In this example, the time when the current position cannot be detected continuously is described as 5 seconds and the amount of change is 30 degrees. However, these values may be set in any manner.

  The monitoring unit 22 monitors the position DB 12 and, when the position data table 30 has not been updated for 5 seconds or more, notifies the determination unit 15 together with the last update time 31 of the position data table 30. The determination unit 15 receives a notification from the monitoring unit 22 (step S121).

  The determination unit 15 that has received the notification from the monitoring unit 22 acquires the current (latest) first azimuth 44 and the last time first azimuth 44 with reference to, for example, the first azimuth DB 20. At this time, the determination unit 15 may acquire a part or all of the first azimuth 44 at the time between these two points along with the first azimuth 44. Then, the determination unit 15 transmits the first orientation 44 to the movement angle calculation unit 21.

  The movement angle calculation unit 21 calculates the movement angle of the map display device 1 from the plurality of received first orientations 44 and returns it to the determination unit 15 (step S122).

  The determination unit 15 determines whether or not the movement angle notified from the movement angle calculation unit 21 is 30 degrees or more (step S123).

  If the movement angle is greater than 30 degrees (step S123: No), the process is terminated. On the other hand, when the movement angle is 30 degrees or less (step S123: Yes), the determination unit 15 notifies the position prediction unit 18 of the determination result.

  Receiving the notification, the position prediction unit 18 refers to the position DB 12, and calculates predicted position data predicted as the current position based on the data 31, 32, and 33 of the position data table 30 (step S124). The position prediction unit 18 notifies the acquired prediction position data to the acquisition unit 10 and the display control unit 13.

  The acquisition unit 10 acquires map data around the predicted position based on the received predicted position data from the map information DB 9 and transmits the map data to the display control unit 13. The display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10 (step S125).

  The display control unit 13 displays the predicted position based on the predicted position data on the map image (step S126).

  In the map display device 1 having the position prediction function, for example, even when the GPS signal cannot be received and the current position cannot be detected continuously, the electronic compass is detected together with the already detected position data and the moving speed. The current position can be predicted and displayed by using the direction detected by.

  Next, the map display device 1 having a link matching correction function will be described below. FIG. 11 is an explanatory diagram for explaining the link matching and link matching correction functions.

  First, link matching will be described. Link matching is a function of correcting an error when the current position based on the position data 32 deviates from the road in map data representing a road by a node and a link connected via the node. In the illustrated example, links A1, A2 and C1 are connected to the node n1 through this. Further, links C1, B1, and B2 are connected to the node n2 through this. A point “◯” is an actual measurement position detected by the arithmetic processing unit 11 described above. This is corrected to the optimum point on the road in consideration of the direction of travel. The corrected position after correction is indicated by “●” in FIG. The detected actual positions a and b are corrected on the closest link A2.

  Next, the link matching correction function will be described. The link matching correction function is a function for determining whether or not the correction position subjected to the link matching is correct, and correcting if the correction position is not correct. In the illustrated example, the measured position c detected by the arithmetic processing unit 11 is closest to the link B1. For this reason, the actual measurement position c should be link-matched with the link B1. However, there are two nodes n1 and n2 between the link A2 and the link B1, and the links A2 and B1 are not continuous. Therefore, the map display apparatus 1 may not have moved from the link A2 to the link B1 via the node n1, the link C1, and the node n2, but may have moved the link A1 only through the node n1. In such a case, for the detected position c, before displaying the correction position on the link B1, it is determined whether or not the correction position is correct based on the first direction detected by the electronic compass. Estimate the correction position.

  For the map display device 1 having the link matching correction function, “the first link in which the matching processing unit 19 matched the current position at the first time and the matching processing unit 19 after the first time The case where the display switching condition “whether or not the second link that matches the current position at time 2” is not continuous will be described below. In addition, about the above-mentioned component, when the function is added, it adds to the following.

  The matching processing unit 19 performs link matching. For example, the matching processing unit 19 refers to the position DB 12 and corrects the position data 32 of the current position on the nearest link. The matching processing unit 19 also corrects the position data 32 of the current position (hereinafter referred to as an actual measurement position) acquired from the position DB 12 and the time 31 when the position data 32 of the actual position is detected (hereinafter referred to as correction). (Corresponding to the position) and the link where the correction position exists are stored in the matching storage unit 23.

  FIG. 12 is a diagram illustrating a matching data table 50 that is an example of a structure in the matching storage unit 23. The matching data table 50 includes, as its data structure, time 51, latitude data 52a and longitude data 52b which are position data 52 of the current position, latitude data 53a and longitude data 53b which are position data 53 of the correction position, and correction. And a link 54 where the position exists.

  The determination unit 15 extracts the switching display condition in the condition storage unit 14. Here, for example, “the first link in which the matching processing unit 19 matched the current position at the first time and the current position at the second time after the first time are matched. The switching display condition “whether or not the second link is not continuous” is extracted. In other words, the switching display condition is “the first link where the correction position at the first time exists and the second link where the correction position at the second time after the first time exists”. Whether it is not continuous. " The determination unit 15 refers to the matching storage unit 23, and the second link 54 in which the position data 53 of the correction position at the current (latest) time 51 that is the second time exists and the current ( It is determined whether or not the first link 54 in which the position data 53 of the correction position at the time 51 immediately before the latest time exists continues.

  Further, the determination unit 15 is based on the direction detected by the electronic compass 7 between the first time 51 and the second time 51 when the first link 54 and the second link 54 are not continuous. Thus, it is determined whether the matching with respect to the second link 54 is correct (that is, whether the correction position is correct). For example, when the determination unit 15 determines that the first link 54 and the second link 54 are not continuous, the determination unit 15 refers to the first azimuth DB 20 and refers to the current (latest) time 31 and the previous one. The change of the first azimuth 44 during the time 31 is calculated, and it is determined whether or not the current position exists in the second link 54. This is determined, for example, based on whether or not the change in the first azimuth 44 between the current (latest) time 31 calculated by the determination unit 15 and the previous time 31 is greater than or equal to a predetermined angle. The determination unit 15 refers to the position DB 20 and determines whether or not the change in the first orientation 44 during this time is equal to or greater than a predetermined angle. When the determination unit 15 determines that the change in the first azimuth 44 is equal to or greater than the predetermined angle, the determination unit 15 determines that the current position is on the second link 54 and the change in the first azimuth 44 is greater than the predetermined angle. If it is smaller, it is determined that the current position does not exist on the second link. The determination unit 15 notifies the display control unit 13 of a determination result as to whether or not the current position exists on the second link 54.

  The display control unit 13 receives a notification of the determination result from the determination unit 15. When the determination result is “the current position exists in the second link 54”, the display control unit 13 refers to the matching storage unit 23 and extracts the position data 53 of the correction position. The display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10, acquires the position data 53 of the correction position from the matching storage unit 23, and displays it on the map image. .

  If the determination result is “the current position does not exist on the second link 54”, the display control unit 13 notifies the matching processing unit 19 of the result and requests another link matching. Then, the display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10, and acquires the position data 53 of the corrected position corrected again from the matching storage unit 23. , Display on the map image.

  The matching processing unit 19 that has received the determination result that “the current position does not exist on the second link 54” from the display control unit 13 performs link matching of the actually measured position again. Link matching in this case is also performed with reference to the first direction 44 of the first direction DB 20. The matching processing unit 19 stores the position data 53 of the correction position and the link 54 by the link matching again in the matching storage unit 23.

  FIG. 13 shows that the display switching condition is that “the first link where the correction position at the first time exists and the second link where the correction position at the second time after the first time exists are continuous. It is a flowchart showing operation | movement of the map display apparatus 1 when the condition of "whether it is not" is set.

  The matching processing unit 19 performs link matching of the measured position at the current time 51 (step S131). Then, the position data 53 and the link 54 of the correction position as a result are stored in the matching storage unit 23.

  The determination unit 15 refers to the matching storage unit 23, and determines whether or not the link 54 at the current time 51 and the link 54 at the time 51 immediately before the current time are continuous (step S132).

  When it is determined that the link 54 at the current time 51 and the link 54 at the time 51 immediately before the current time are continuous (step S132: Yes), the determination unit 15 displays the determination result as the display control unit 13. Notify

  Receiving the notification from the determination unit 15, the display control unit 13 refers to the matching storage unit 23 and extracts the position data 53 of the correction position at the current time 51 (step S134). Then, the display control unit 13 displays a map image on the display 5 based on the map data received from the acquisition unit 10 (step S135), acquires the position data 53 of the correction position from the matching storage unit 23, and displays the map. The image is displayed on the image (step S136).

  When it is determined that the link 54 at the current time 51 and the link 54 at the time 51 immediately prior to the current time are not continuous (step S132: No), the determination unit 15 subsequently determines that “the current position is It is determined whether or not it exists on the link 54 at the current time 51 (step S133). As described above, in the determination, the first azimuth 44 has changed by a predetermined angle or more between the current time 51 determined that the determination unit 15 is not continuous in step S132 and the time 51 immediately before the current time. This is done based on whether or not. If it is determined that the change in the first azimuth 44 is greater than or equal to a predetermined angle, it is determined that the current position is on the second link 54, and if the change in the first azimuth 44 is smaller than the predetermined angle, It is determined that the current position does not exist on the second link.

  If the determination result in step S133 is “the current position exists on the link 54 at the current time 51” (step S133: Yes), the process proceeds to step S134.

  When the determination result in step S133 is “the current position does not exist on the link 54 at the current time 51” (step S133: No), the display control unit 13 notifies the matching processing unit 19 of the result. Then, another link matching is requested (step S137).

  Upon receiving the request in step S137, the matching processing unit 19 returns to step S131, and again performs link matching for the measured position at the current time 51 (step S131). The matching processing unit 19 stores the result of link matching again in the matching storage unit 23.

  In the present embodiment, when the result of link matching is greatly deviated, link matching is performed again with reference to the direction detected by the electronic compass. This improves the accuracy of link matching.

  The above-described embodiments of the present invention are examples for explaining the present invention, and are not intended to limit the scope of the present invention only to those embodiments. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Map display apparatus 2 GPS satellite 3 Vehicle 4 Map data processing part 5 Display 6 Receiver 7 Electronic compass 8 Input part 9 Map database 10 Acquisition part 11 Arithmetic processing part 12 Position database 13 Display control part 14 Electronic compass 15 Determination part 16 Route Search unit 17 Extraction unit 18 Position prediction unit 19 Matching processing unit

Claims (9)

Processes map data executed by an information processing apparatus comprising an electronic compass for detecting a first orientation, a display, and map data storage means for storing map data for displaying a map image on the display A computer program for
When executed on the information processing apparatus,
Detecting a current position of the information processing apparatus at each time at a plurality of different times; and
Storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit;
Calculating a second orientation in which the information processing apparatus is proceeding based on position data stored in the position data means;
A display control step of reflecting a second orientation calculated in the second orientation calculation step to display a map image based on the map data on a display and to display a current position of the information processing apparatus on the map image. When,
Determining whether or not a predetermined display switching condition is satisfied, and
When it is determined in the determination step that the display switching condition is satisfied, the display control step displays the map image displayed on the display reflecting the second orientation as the first display. A computer program characterized by switching to a display reflecting the direction. The step of calculating the moving speed of the information processing device based on the position data stored in the position data storage means is further realized,
The display switching condition is whether or not the moving speed of the information processing apparatus is a threshold value or less,
When it is determined by the determination step that the moving speed is equal to or less than a threshold value, the display control step displays a map image displayed heading up on the display based on the second orientation, The computer program according to claim 1, wherein the computer program switches to a heading-up display based on the first orientation. The display switching condition is whether or not the current position of the information processing apparatus is on an expressway,
When it is determined by the determination step that the current position is not on the highway, the display control step displays a map image displayed heading up on the display based on the second direction. The computer program according to claim 1, wherein the computer program switches to a heading-up display based on the first orientation. The condition is whether or not the second orientation of the information processing apparatus has changed more than a threshold value within a predetermined time,
When it is determined by the determination step that the second orientation of the information processing apparatus has changed by a threshold value or more within a predetermined time, the display control step is performed on the display in the second orientation. The computer program according to claim 1, wherein a map image displayed based on heading-up is switched to heading-up display based on the first orientation. Searching for a route from the departure point to the destination of the information processing device;
A step of extracting a bending point where the route bends by a predetermined angle or more in the route searched by the route searching step is further realized;
The display switching condition is whether or not the current position of the moving information processing apparatus is around the bending point,
When the determination step determines that the current position of the information processing apparatus is around the bending point extracted by the extraction step, the display control step is performed on the display in the second orientation. The computer program according to claim 1, wherein a map image displayed based on heading-up is switched to heading-up display based on the first orientation. Processes map data executed by an information processing apparatus comprising an electronic compass for detecting a first orientation, a display, and map data storage means storing map data for displaying a map image on the display A computer program for
When executed on the information processing apparatus,
Detecting a current position of the information processing apparatus at each time at a plurality of different times; and
Storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit;
Calculating a second orientation in which the information processing apparatus is proceeding based on position data stored in the position data means;
Reflecting the second azimuth calculated in the second azimuth calculating step, displaying a map image based on the map data on a display, and displaying a current position of the information processing apparatus on the map image;
When the position detection step cannot detect the current position continuously for a predetermined time after the first time, the current position of the information processing apparatus is determined based on the position data and the moving speed before the first time. Predicting steps,
Determining whether the amount of change between the first orientation detected by the electronic compass before the first time and the first orientation detected by the electronic compass after the first time is equal to or less than a predetermined amount; Is realized,
The amount of change between the first azimuth detected by the electronic compass before the first time and the first azimuth detected by the electronic compass after the first time by the determination step is equal to or less than a predetermined amount. When it is determined that the computer program, the display control step displays the current position of the information processing apparatus predicted by the prediction step on a map image of the display Processes map data executed by an information processing apparatus including an electronic compass for detecting a first orientation, a display, and map data storage means for storing map data for displaying a map image on the display A computer program for
When executed on the information processing apparatus,
Detecting a current position of the information processing apparatus at each time at a plurality of different times; and
Storing position data indicating a current position of the information processing apparatus at each time detected by the position detection step in a position data storage unit;
Performing link matching;
The first link in which the link matching step matches the current position at the first time, and the second link in which the link matching step matches the current position at the second time after the first time. Determining whether the matching for the second link is correct or not based on the orientation detected by the electronic compass between the first time and the second time.
Correcting the result of link matching by the link matching step based on the determination result of the correctness determination step;
The step of displaying a map image based on the map data on a display and displaying the current position of the information processing device on the map image based on the processing results of the link matching step and the link matching correction step is realized. The computer program characterized by being made. A method for displaying a map on an information processing apparatus comprising an electronic compass for detecting a first orientation, a display, and map data storage means for storing map data for displaying a map image on the display. And
Detecting a position of the map display device at each time at a plurality of different times; and
Storing position data indicating the current position of the map display device at each time detected by the position detection step in a position data storage means;
Calculating a second direction in which the map display device is traveling based on the position data stored in the position data means;
Reflecting the second azimuth calculated in the second azimuth calculating step, displaying a map image based on the map data on a display, and displaying the current position of the map display device on the map image;
And a step of determining whether or not a predetermined display switching condition is satisfied,
When it is determined in the determination step that the display switching condition is satisfied, the display control step displays the map image displayed on the display reflecting the second orientation as the first display. A method characterized by switching to a display reflecting the direction. A map display device,
Display,
An electronic compass for detecting the first orientation;
Means for storing map data for displaying a map image on the display;
Position detection means for detecting a current position of the map display device at each time at a plurality of different times;
Storage means for storing position data indicating the current position of the map display device at each time detected by the detection means;
Second azimuth calculating means for calculating a second azimuth in which the map display device is traveling based on position data stored in the storage means;
Display control means for reflecting the second azimuth calculated by the second azimuth calculating means and displaying a map image based on the map data on the display and displaying the current position of the map display device on the map image; ,
Determination means for determining whether or not a predetermined display switching condition is satisfied,
When it is determined by the determination means that the display switching condition is satisfied, the display control means displays the map image displayed on the display reflecting the second orientation as the first display. A map display device characterized by switching to a display reflecting the direction.

Images