JP2019200115A - Navigation device, control method, and program - Google Patents

Abstract

To provide a navigation device, a control method, and a program which can appropriately display the vehicle position.SOLUTION: A navigation device relating to the present invention comprises: a position information acquisition unit 111 for acquiring the vehicle position on the basis of a positioning signal from a satellite; an estimation accuracy determination unit 112 for determining whether or not the accuracy of estimating the vehicle position by the position information acquisition unit 111 is low; a specification unit 115 for specifying, on the basis of the travel route and travel direction of the vehicle in map information, a change position where it is assumed that the estimation accuracy becomes high; and a display control unit 116 for changing the display position of the vehicle in the map information so as to indicate the change position when it is determined that the estimation accuracy is low.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a navigation device, a control method, and a program.

  Patent Document 1 discloses an in-vehicle device that measures the position of the vehicle using GPS navigation and autonomous navigation. This in-vehicle device detects a non-reception section where a GPS signal cannot be received, such as a tunnel. Further, the vehicle-mounted device monitors the capture state of the GPS satellite. During the period when GPS satellites are not captured, the automatic distance is calculated by autonomous navigation, and the position on the screen of the vehicle that has passed the non-receiving section is corrected based on the distance on the map of the non-receiving section. .

JP 2010-175323 A

  In recent years, navigation using portable terminals such as smartphones and tablet PCs has been used. A mobile terminal such as a smartphone or a tablet PC cannot use a vehicle speed pulse (vehicle speed signal) from an automobile. Even in portable navigation devices, vehicle speed pulses may not be available. Furthermore, even if the navigation device is mounted on a vehicle, the vehicle speed pulse may not be acquired in the case of a foreign vehicle or the like.

  A navigation device that cannot use vehicle speed pulses may not be able to properly display its own vehicle position when it cannot receive GPS signals. For example, while traveling in a tunnel or around a high-rise building, the GPS signal cannot be acquired properly, and the vehicle position is displayed with a shift.

  This invention is made | formed in view of such a situation, and provides the navigation apparatus, the display control method, and program which can display the own vehicle position appropriately.

  A navigation device according to the present invention is based on a positioning signal from a satellite, a position information acquisition unit that acquires a vehicle position, and an estimation that determines whether or not the estimation accuracy of the vehicle position in the position information acquisition unit is low When it is determined that the accuracy determination unit, the specifying unit that identifies the change position where the estimation accuracy is assumed to be high, and the estimation accuracy are low, based on the travel path and the traveling direction of the vehicle on the map information And a display control unit that changes the display position of the vehicle on the map information so as to indicate the change position.

  The navigation apparatus control method according to the present invention includes a step of acquiring a vehicle position based on a positioning signal from a satellite, a step of determining whether or not the estimation accuracy of the vehicle position is low, A step of identifying a change position where the estimation accuracy is assumed to be high based on a travel route and a traveling direction of the vehicle, and the vehicle on the map information when it is determined that the estimation accuracy is low. Changing the display position to indicate the change position.

  A program according to the present invention includes a step of acquiring a vehicle position based on a positioning signal from a satellite, a step of determining whether or not the estimation accuracy of the vehicle position is low, A step of identifying a change position where the estimation accuracy is assumed to be high based on a travel path and a traveling direction, and a display position of the vehicle on the map information when the estimation accuracy is determined to be low. And causing the computer to execute a step of changing to indicate the change position.

  According to the present invention, it is possible to provide a navigation device, a display control method, and a program that can appropriately display the vehicle position.

It is a functional block diagram which shows the structure of a navigation apparatus. It is a figure which shows the example which has passed the tunnel. It is a figure for demonstrating the example 1 of a change position. It is a figure for demonstrating the example 2 of a change position. It is a figure for demonstrating the example 3 of a change position. It is a figure for demonstrating the example 4 of a change position.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

  The navigation device according to the present embodiment estimates the position of the host vehicle only from the positioning signal from the satellite. That is, the navigation device according to the present embodiment estimates the vehicle position without using the vehicle speed pulse. The navigation device according to the present embodiment is a navigation device that does not use autonomous navigation.

  The positioning signal is, for example, a GPS signal from a GPS (Global Positioning System) satellite. Of course, a satellite positioning system other than GPS, for example, a quasi-zenith satellite positioning system may be used. In the following description, a navigation device that acquires the vehicle position only by GPS navigation using GPS signals will be described.

  The navigation device and its control method according to the present embodiment can be typically realized by a mobile terminal such as a smartphone or a tablet PC. That is, the mobile terminal in which the navigation application (application program) is installed becomes the navigation device. Alternatively, it may be realized by a portable navigation device. Furthermore, the vehicle-mounted navigation apparatus mounted in the foreign vehicle etc. which cannot use a vehicle speed pulse may be sufficient. That is, the navigation device is used in a state where it is not connected to a CAN (Controller Area Network) or the like.

Embodiment 1 FIG.
FIG. 1 is a functional block diagram showing the configuration of the navigation device 100 according to the present embodiment. The navigation device 100 includes a control unit 110, a GPS device 120, an operation unit 130, a storage unit 140, and a display unit 150.

  The control unit 110 includes a position information acquisition unit 111, an estimation accuracy determination unit 112, an operation reception control unit 113, a map information acquisition unit 114, a specification unit 115, and a display control unit 116. The control unit 110 includes a memory that stores a program and a processor such as a CPU (Central Processing Unit). That is, the processing in each functional block is performed by the processor executing the program.

  The GPS device 120 includes an antenna, a receiving circuit, and the like. The GPS device 120 receives GPS signals from a plurality of artificial satellites. The GPS device 120 performs processing such as amplification, A / D conversion, and demodulation on the GPS signal. The GPS device 120 outputs the processed GPS signal to the position information acquisition unit 111. The position information acquisition unit 111 acquires position information related to the current vehicle position based on the GPS signal.

  The position information of the own vehicle position includes, for example, latitude and longitude. The position information may include altitude. In addition, since the calculation methods, such as latitude and longitude using a GPS signal, are well-known, detailed description is abbreviate | omitted. The GPS device 120 and the position information acquisition unit 111 cooperate to calculate the current position of the vehicle based on the GPS signal. The GPS device 120 repeatedly receives GPS signals. The position information acquisition unit 111 updates the current vehicle position based on the latest GPS signal. That is, the position information acquisition unit 111 estimates the latest vehicle position.

  The estimation accuracy determination unit 112 determines the estimation accuracy of the host vehicle position acquired by the position information acquisition unit 111. That is, the estimation accuracy determination unit 112 determines whether or not the estimation accuracy of the vehicle position acquired by the position information acquisition unit 111 is high. For example, the estimation accuracy determination unit 112 determines the estimation accuracy according to the number of received GPS signals.

  As a specific example, when the GPS device 120 receives GPS signals from four or more GPS satellites, the estimation accuracy determination unit 112 determines that the estimation accuracy is high. When the GPS device 120 receives GPS signals from three or less GPS satellites, the estimation accuracy determination unit 112 determines that the estimation accuracy is low. That is, the position information estimated based on the three GPS signals has low estimation accuracy, and the current position estimated based on the four GPS signals has high estimation accuracy. When the own vehicle passes through a tunnel or a high-rise building group, the GPS device 120 cannot receive a GPS signal properly. Therefore, the estimation accuracy of the own vehicle position is lowered, and the own vehicle position is largely deviated.

  The estimation accuracy determination unit 112 may determine whether or not the estimation accuracy of the vehicle position is high based on the map information acquired by the map information acquisition unit 114. For example, based on the vehicle position and map information, when the vehicle position passes through the tunnel entrance by judging that there is a section that may not be able to properly receive GPS signals such as a tunnel in the traveling direction, It is determined whether or not the estimation accuracy of the vehicle position is high. Moreover, it is good also as acquiring the information which shows that it is the area which cannot receive a GPS signal appropriately with map information.

  The operation unit 130 includes an input device such as an operation panel or a remote controller. The operation unit 130 may be configured with a touch panel integrated with the display unit 150. Alternatively, the operation unit 130 may include a microphone for voice input operation. The operation unit 130 receives a user's navigation operation. For example, the user can input a destination input, a route search start to the destination, a map enlargement / reduction, a map scroll, a display setting change, and the like by operating the operation unit 130. The operation unit 130 outputs an operation signal corresponding to the user operation to the operation reception control unit 113.

  The operation reception control unit 113 causes the navigation device 100 to execute processing according to the operation signal from the operation unit 130. Thereby, the navigation device 100 executes processing such as route search. The operation unit 130 and the operation reception control unit 113 cooperate to perform processing according to a user operation. Thereby, the navigation apparatus 100 performs the process according to user operation.

  The storage unit 140 has a recording medium such as a hard disk or a memory, and stores map information necessary for navigation. Note that when the navigation device 100 is a smartphone or the like, the storage unit 140 may be configured to temporarily store map information received from an external server.

  The map information includes route calculation data, road data, background data, and the like. The route calculation data is data used when searching for a route to the destination. The road data is data representing the shape, type, width, etc. of the road. In the map information, the minimum unit of each road is called a link. That is, in the map information, each road is composed of a plurality of links. Adjacent links are connected via a point called a node, and each node represents an end point of the link. A node corresponds to a branch point such as an intersection.

  The background data is data representing the background of the map. The map background is various components other than roads existing on the map. For example, rivers, railways, green zones, various structures, etc. are represented by background data. The background data includes information on objects existing around each branch point and road. The objects include, for example, buildings such as buildings, and artificial structures such as tunnels, parks, and facilities. Further, the object includes natural objects such as rivers, lakes, forests, and mountains. The object information includes, for example, position coordinates and a three-dimensional shape (size, orientation, appearance, etc.).

  Furthermore, the road data includes information such as a tunnel that makes it difficult to receive GPS signals. For example, the road data includes information such as a tunnel exit position and distance. In addition, when there is a branch in the tunnel, information on the position and direction of the branch point and the distance from the entrance to the branch point is included. In addition, candidates for changing positions are registered in the map information. The change position is, for example, a tunnel exit or a branch point. The change position will be described later.

  The display unit 150 includes a display such as a liquid crystal monitor. The display control unit 116 controls display on the display unit 150. That is, the display control unit 116 generates a display control signal corresponding to the image displayed on the display unit 150. Then, the display unit 150 performs display based on the display control signal from the display control unit 116. The display control unit 116 and the display unit 150 cooperate to display a map or the like necessary for navigation.

  Specifically, the display control unit 116 and the display unit 150 display a map on the display based on the map information stored in the storage unit 140. Further, the display control unit 116 and the display unit 150 superimpose and display an icon indicating the current vehicle position on the map. The display control unit 116 and the display unit 150 scroll the displayed map in accordance with the movement of the vehicle position so that the icon of the vehicle position is always at a predetermined position such as the center of the display screen.

  The identification unit 115 identifies a change position that is assumed to have high estimation accuracy based on the traveling path and traveling direction of the vehicle on the map information. Hereinafter, the details of the change position will be described with reference to FIG. FIG. 2 is a diagram for explaining changes in the vehicle position on the display screen.

  FIG. 2 shows a case where there is a tunnel T in the middle of the traveling path R1. That is, in FIG. 2, the map in case the own vehicle passes the tunnel T is shown typically. In FIG. 2, the own vehicle is moving from the bottom to the top. That is, the lower end of the tunnel T is the entrance T1, and the upper end is the exit T2. The positions of the entrance T1 and the exit T2 of the tunnel T are registered in the map information. The solid line portion of the travel route R1 is a section where the estimation accuracy is high, and the broken line portion is a section where the estimation accuracy is low.

  Since the estimation accuracy is high at the timing when the host vehicle enters the tunnel T, an icon 30 indicating the host vehicle position is displayed at the entrance T1 of the tunnel T. The display position of the icon 30 at the entrance T1 of the tunnel T is defined as a display position P1. When the own vehicle enters the tunnel T, the GPS device 120 cannot receive the GPS signal from the GPS satellite. It is difficult to receive GPS signals between the entrance T1 and the exit T2 of the tunnel T. During the passage of the tunnel T, the estimation accuracy determination unit 112 determines that the estimation accuracy is low. When it is determined that the estimation accuracy is low, the own vehicle position acquired by the position information acquisition unit 111 may be greatly deviated from the inside of the tunnel T like the icon 31 of the own vehicle position.

  In this case, the specifying unit 115 specifies the exit T2 of the tunnel T as the change position P2 based on the travel route R1 and the traveling direction on the map information. That is, the specifying unit 115 specifies the next change position candidate on the travel route R1 as the change position P2. The display control unit 116 displays an icon 32 indicating the current vehicle position at the change position P2. That is, the display control unit 116 performs display control so as to change the vehicle position from the display position P1 to the change position P2. The display control unit 116 changes the display position of the own vehicle so as to indicate the change position P2. Therefore, the icon is changed from the display position P1 to the change position P2 on the display screen. Until the estimation accuracy by the estimation accuracy determination unit 112 becomes high, the display control unit 116 displays the icon 32 indicating the vehicle position at the change position P2. At this time, a message such as “passing tunnel” or “waiting for GPS signal reception” may be displayed on the display screen.

  By doing in this way, the position shift of an icon can be made small in the timing which the own vehicle passed the tunnel T. In other words, if the position of the vehicle acquired in a state where the estimation accuracy is low is indicated by the icon 31, the display position of the icon 32 changes greatly at the timing when the estimation accuracy is increased. That is, the icon 31 is instantaneously switched to the icon 32 on the display screen. Therefore, it becomes difficult for a user (for example, a driver) to grasp the vehicle position.

  Thus, as in the present embodiment, when the estimation accuracy is low, the icon 32 is displayed at the change position where the estimation accuracy of the vehicle position is assumed to be high. By doing so, it is possible to prevent a sudden change in the icon display position at the timing when the estimation accuracy increases. Therefore, the vehicle position can be appropriately displayed on the map, and the user can easily grasp the vehicle position. In particular, there may be elements that require attention such as a branch point, an intersection, or a sharp curve in the vicinity of the exit T2 of the tunnel T, specifically immediately after exiting the exit T2 of the tunnel T. While traveling through the tunnel T, if the vehicle T is not in the position where the exit T2 of the tunnel T is normally displayed in the display range of the display screen, or if the vehicle position is shifted like the vehicle position icon 31, the display screen Even when the exit T2 of the tunnel T is not displayed in the display range, the display range of the display screen is displayed so that the change position P2 is a predetermined position such as the center of the display screen. For this reason, the user can grasp in advance the elements that need attention in the vicinity of the exit T2 of the tunnel T, and can prevent the dredging.

  Thus, the change position P2 is set as a temporary current position. That is, while the estimation accuracy is low, an icon indicating the vehicle position is displayed at the change position P2. For example, the map information includes the positions of the entrance T1 and the exit T2 of the tunnel T. In the map information, the entrance T1 and the exit T2 are registered as candidates for change positions. The entrance T1 and the exit T2 are switched according to the traveling direction of the vehicle.

  The specifying unit 115 specifies the change position from the change position candidates according to the own vehicle position acquired in a state where the estimation accuracy is high and the traveling direction. For example, before the estimation accuracy is lowered, the specifying unit 115 specifies the change position in advance based on the traveling path R1 of the host vehicle and the traveling direction. Thereby, the specifying unit 115 can set an appropriate change position. When the estimation accuracy becomes low, the specifying unit 115 displays an icon at the change position specified by the specifying unit 115. When entering the tunnel T, the estimation accuracy becomes low, so the identifying unit 115 displays an icon with the tunnel exit T2 as the change position P2. After exiting the tunnel T and the estimation accuracy is increased, an icon is displayed at the vehicle position acquired by the position information acquisition unit 111.

  Further, the changed position may be updated while the vehicle position is moving with high estimation accuracy. When the tunnel continues, every time the own vehicle position passes through the tunnel, the specifying unit 115 updates the exit of the next tunnel as the changed position. Thereby, even if it is a case where it passes through the tunnel which cannot receive a GPS signal continuously, a self-vehicle position can be displayed appropriately.

  Further, the change position P2 may not completely coincide with the exit T2 of the tunnel T. That is, the display position of the icon 32 indicating the current position of the host vehicle may be around the exit T2. For example, the icon 32 may be displayed immediately before the exit T2 of the tunnel T.

Embodiment 2. FIG.
In the second embodiment, the condition of the change position specified by the specifying unit 115 is different from that in the first embodiment. Since the processing other than the specifying unit 115 is the same as that of the first embodiment, the description thereof is omitted.

  In the present embodiment, the specifying unit 115 specifies a change position where the user can determine the vehicle position on the map. The change position is a position at which the user can confirm the own vehicle position visually. For example, while traveling in a tunnel, it is difficult for the user to determine which position in the tunnel. When passing through the tunnel, when the own vehicle approaches the tunnel exit or passes through the tunnel exit, it can be visually confirmed that the user is immediately before the tunnel exit or the tunnel exit. Therefore, the tunnel exit or the tunnel exit is registered as a candidate for the change position. The identifying unit 115 identifies the position immediately before the tunnel exit or the tunnel exit as the change position based on the traveling path R1 and the traveling direction.

  By doing in this way, the shift | offset | difference of the display position in the timing which the own vehicle passed the tunnel can be made small. In other words, if an icon is displayed at the vehicle position acquired in a state where the estimation accuracy is low, the display position of the icon changes greatly at the timing when the estimation accuracy becomes high. When the estimation accuracy becomes low, it is possible to prevent an abrupt change in the display position of the icon by displaying the icon at a change position where the user can specify the vehicle position on the map. Therefore, the own vehicle position can be appropriately displayed on the map, and the user can easily grasp the own vehicle position.

  In this way, the exit T2 of the tunnel T where the user can visually confirm the vehicle position is set as the temporary current position (see FIG. 2). For example, the map information includes position information of the entrance T1 and the exit T2 of the tunnel T. The entrance T1 and the exit T2 are registered in the map information as change position candidates. The entrance T1 and the exit T2 are switched according to the traveling direction of the vehicle. The identifying unit 115 identifies the change position according to the current position acquired in a state where the estimation accuracy is high and the traveling direction thereof.

  The specifying unit 115 specifies the changed position according to the own vehicle position acquired in a state where the estimation accuracy is high and the traveling direction. That is, the specifying unit 115 specifies the change position in advance based on the vehicle position and the traveling direction before the estimation accuracy becomes low. Thereby, the specifying unit 115 can set an appropriate change position. When the estimation accuracy becomes low, an icon is displayed at the change position specified by the specifying unit 115.

  The specifying unit 115 specifies a change position where the user can determine the vehicle position on the map. Further, when the vehicle position moves in a state where the estimation accuracy is high, the changed position may be updated. For example, when tunnels continue, every time the vehicle position passes through the tunnel, the specifying unit 115 updates the exit of the next tunnel as the change position. Thereby, even if it is a case where it passes through the tunnel which cannot receive a GPS signal, the own vehicle position can be displayed appropriately.

  Further, when there is a branch point in the tunnel, the specifying unit 115 may specify the branch point in the tunnel as the change position. That is, when there is a branch point in the tunnel, it can be recognized that the user passes through the branch point. The identifying unit 115 identifies the branch point at which the user can visually determine the vehicle position as the change position. The display control unit 116 changes the display position of the own vehicle so as to indicate the change position.

  Note that Embodiment 1 and Embodiment 2 can be used in appropriate combination. That is, both the position where the estimation accuracy is assumed to be high and the position where the user can determine the vehicle position on the map can be set as the change positions.

(Example of change position 1)
In the first and second embodiments, the exit of the tunnel is the change position, but the change position is not limited to the tunnel exit. The example of the change position in Embodiment 1, 2 is demonstrated. FIG. 3 is a diagram schematically illustrating an example of traveling in an urban area where a high-rise building group is present. In Example 1, the example which goes straight on the road between the buildings 41-43 which are high-rise buildings is shown. Further, there are intersections C1 to C4 between the high-rise buildings, and the vehicle passes through the intersection C1, the intersection C2, the intersection C3, and the intersection C4 in this order.

  When a GPS signal cannot be properly received between the two buildings 41, the estimation accuracy is low in the section between the intersection C1 and the intersection C2. On the other hand, at the intersection C1 and the intersection C2, the GPS device 120 can appropriately receive the GPS signal, and the estimation accuracy becomes high. The state where the GPS signal cannot be properly received is, for example, the case where the GPS device 120 receives GPS signals from three or less GPS satellites, and the state where the GPS signal is properly received is, for example, This is a case where the GPS device 120 receives GPS signals from four or more GPS satellites. For example, when the estimation accuracy becomes low due to the vehicle passing through the display position P11, the specifying unit 115 specifies the position of the intersection C2 as the change position P12. Therefore, the icon 30 indicating the vehicle position is switched from the display position P11 to the change position P12.

  When the vehicle further goes straight and passes through the intersection C2, it enters between the buildings 42. Similarly, when GPS signals cannot be properly received between the buildings 42, the estimation accuracy is lowered in the section between the intersection C2 and the intersection C3. On the other hand, at the intersection C3, since the GPS device 120 can receive GPS signals, the estimation accuracy is increased. When the estimation accuracy becomes low due to the host vehicle passing through the display position P13, the specifying unit 115 specifies the position of the intersection C3 as the change position P14. Therefore, the icon 30 indicating the vehicle position is switched from the display position P13 to the change position P14. When the vehicle goes straight ahead and passes through the intersection C3, it enters between the buildings 44. Similarly, when the GPS signal cannot be received between the buildings 43, the icon 30 indicating the own vehicle position is switched from the change position P15 to the change position P16.

  When the own vehicle passes the intersections C1 to C4, the specifying unit 115 specifies the change position P12, the change position P14, and the change position P16 in order. When the icon 30 indicating the vehicle position is displayed at the changed position with a low estimation accuracy, the display form may be changed from the icon 30 with a high estimation accuracy.

  In Example 1, intersections C1 to C4 are registered as candidates for change positions. In the first embodiment, the intersections C2 to C4 are changed positions that are assumed to increase the estimation accuracy of the vehicle position. In the second embodiment, the intersections C2 to C4 are changed positions where the user can determine the vehicle position on the map. And after passing the intersection C1, when a GPS signal cannot be received and estimation accuracy falls, the own vehicle position is displayed on a change position. Thereby, the own vehicle position can be appropriately displayed, and the user can easily grasp the own vehicle position.

  Thus, in the examples of the first and second embodiments, not only the exit of the tunnel but also the intersection can be set as a candidate for the change position. Of course, not only an intersection but a branch point can be a candidate for a change position. That is, a branch point such as a cross, a T-shape, or a Y-shape can be set as a candidate for the change position.

(Example 2 of change position)
The change position according to Example 2 will be described with reference to FIG. FIG. 4 also shows an example of going straight on the road between the buildings 41 to 43 as in the first example. In FIG. 4, it is assumed that the GPS device 120 cannot properly receive GPS signals in the entire section from the intersection C1 to the intersection C4. In other words, in addition to the section in which the estimation accuracy is low in Example 1, it is assumed that the estimation accuracy is low at the intersection C2 and the intersection C3.

  When the own vehicle passes through the intersections C1 to C4, when the estimation accuracy becomes low due to the own vehicle passing through the display position P21, the specifying unit 115 specifies the change position P22. Therefore, the icons 30 are displayed in the order from the display position P21 to the change position P22. The icon 30 indicating the own vehicle position is switched from the display position P21 to the change position P22.

  In Example 2, the intersection C1 and the intersection C4 are registered as change position candidates. In the first embodiment, the intersection C4 is a changed position where the estimation accuracy of the vehicle position is assumed to be high. When the GPS signal cannot be received after passing through the intersection C1 and the estimation accuracy is lowered, the vehicle position icon 30 is displayed at the change position P22. Thereby, the own vehicle position can be appropriately displayed, and the user can easily grasp the own vehicle position.

  In Example 2, it is registered in the traffic history that GPS signals could not be received at the intersection C2 and the intersection C3 during past traffic. That is, the intersection C2 and the intersection C3 whose estimation accuracy is low are excluded from the candidates for change positions. When the vehicle passes through the intersection C1, the identifying unit 115 refers to the past traffic history and identifies the intersection C4 as the change position P22. As described above, by excluding the intersection C2 and the intersection C3, which have low estimation accuracy, from the candidate for the change position, the vehicle position can be appropriately displayed on the map.

  In addition, you may make it accumulate | store the traffic history which was not able to receive a GPS signal when vehicles other than the own vehicle passed. That is, a section where it is difficult to receive a GPS signal may be excluded from candidates for change positions with reference to the traffic history of other vehicles. Usually, locations where GPS signals from GPS satellites cannot be received are determined by the topography and the height of the building. Therefore, when the GPS devices of other navigation devices cannot receive GPS signals at the intersections C2 and C3, the intersections C2 and C3 are registered as places where the estimation accuracy is lowered. That is, the intersections C2 and C3 are excluded from the candidates for change positions.

  Thus, the traffic history which shows whether the several navigation apparatus was able to receive the GPS signal is accumulate | stored in a server. Then, candidates for change positions may be excluded using the travel histories of a plurality of navigation devices. That is, an intersection or the like that is assumed to have a low estimation accuracy is excluded from the change position candidates. Further, the control unit 110 may learn a candidate for a change position from map information, a traffic history, and the like by a learning function.

  Further, as in the second embodiment, when the position where the user can determine the own vehicle position on the map is the change position, the specifying unit 115 changes the change position P12 and the change position P14 as in FIG. To identify. That is, even if the estimation accuracy is low between the intersection C1 and the intersection C4, if it is an intersection, the user can visually recognize that the vehicle is at the intersection. Therefore, the identifying unit 115 may set the intersections C2 and C3 where the estimation accuracy is assumed to be low as the change position P12 and the change position P14.

(Example 3)
In Example 3, the specifying unit 115 specifies the change position according to the route search result. FIG. 5 shows an example 3 in which the vehicle travels straight from the intersection C1 to the intersection C3 and turns right at the intersection C3. That is, as a result of the route search, routes that pass through the intersection C1, the intersection C2, the intersection C3, and the intersection C5 in this order are registered.

  As in Example 1, when the estimation accuracy is high at the intersection C2 and the intersection C3, the specifying unit 115 specifies the intersection C2, the intersection C3, and the intersection C5 as the change position P32, the change position P33, and the change position P34.

  Alternatively, as in Example 2, when the estimation accuracy is low at the intersection C2 and the intersection C3, the specifying unit 115 specifies the intersection C5 as the change position P34.

  As described above, the specifying unit 115 specifies the change position according to the result of the route search. Thereby, the own vehicle position can be appropriately displayed, and the user can easily grasp the own vehicle position.

(Example 4)
FIG. 6 shows a case where the branch point C22 is in the middle of the tunnel T. In the following description, the entrance of the tunnel T is referred to as an entrance T21, one exit is referred to as an exit T22, and the other exit is referred to as an exit T23. The exit T22 is an exit when the vehicle travels straight through the branch point C22, and the exit T23 is an exit when the vehicle travels left at the branch point C22. Since the GPS signal cannot be received in the tunnel T as described in the first embodiment, the current position estimation accuracy is lowered.

  In Example 4, since the branch point C22 as a position where the user can determine the vehicle position exists inside the tunnel where the estimation accuracy is low, the specifying unit 115 specifies the change position P42 as the change position. For example, when passing through the entrance T21 of the tunnel T, the estimation accuracy decreases. In this case, the branch point C22 is specified as the change position P42. That is, the icon 30 displayed at the display position P41 is displayed at the change position P42.

  If it is assumed that the specifying unit 115 has traveled to the branch point C22 after specifying the change position P42 and displaying the icon 30 at the change position P42, the specifying unit 115 determines which of the change position P43 and the change position P44. Or, it is necessary to specify a change position in the direction in which the vehicle travels. For example, when a route search is performed in advance and a route is set, the change position is specified based on the set route. For example, when a route straight from the branch point C22 and exit from the exit T22 is set, the icons 30 are displayed in the order of the change position P44 after the change position P42.

  After the icon 30 is displayed at the change position P42 in the tunnel T, the timing at which the icon 30 is displayed at the change position P44 is when the vehicle position is assumed to be near the branch point C22. The vicinity here is a case where the vehicle position is assumed to be immediately before the branch point C22 or a case where the vehicle position is assumed to have passed the branch point C22.

  The assumption that the vehicle position is in the vicinity of the branch point C22 is, for example, the transition of the position information for each unit time immediately before the specifying unit 115 passes through the entrance T21 acquired by the position information acquiring unit 111, and the map information It is assumed that the calculation is based on the distance information between the entrance T21 and the branch point C22 acquired from the acquisition unit 114.

  Further, when the icon 30 is displayed at the branch point C22, the display unit 150 may display a button, an icon, or the like that determines the traveling direction. Then, the user may input the traveling direction at the branch point C22 by performing an operation input on the operation unit 130 such as a touch panel. When the user inputs that the vehicle goes straight, the display unit 150 switches the display of the icon 30 from the change position P42 to the change position P44. When the user inputs a left turn, the display unit 150 switches the display of the icon 30 from the change position P42 to the change position P43. Of course, the traveling direction may be input by voice input. The specifying unit 115 may specify the change position based on an operation input by the user.

  Furthermore, when the navigation apparatus 100 is equipped with an acceleration sensor, the specifying unit 115 may specify the change position according to the acceleration. For example, when the navigation device 100 is a smartphone equipped with an acceleration sensor, the acceleration sensor detects acceleration. And the specific | specification part 115 determines whether it went straight on the branch point C22 in the tunnel T according to the acceleration, or it turned left. The identification unit 115 identifies the change position according to the advanced direction.

  For example, if the acceleration in the left direction is greater than or equal to a threshold value in a predetermined period before and after the vehicle position is assumed to be in the vicinity of the branch point C22, the specifying unit 115 proceeds to the left at the branch point C22. Determine and specify the change position P43. On the other hand, while no acceleration equal to or greater than the threshold value in the left direction is detected, the specifying unit 115 determines that the vehicle has traveled straight through the branch point C22 and specifies the change position P44. As described above, the specifying unit 115 may specify the change position based on the acceleration.

  As shown in the above embodiment, all or part of the branch points and tunnel exits are registered in the map information as candidates for change positions. Then, the specifying unit 115 specifies the change position from the change position candidates according to the travel path based on the host vehicle position in the state where the estimation accuracy is high and the traveling direction. When the estimation accuracy becomes low, the display control unit 116 displays an icon indicating the vehicle position at the change position.

  Immediately after the estimation accuracy becomes low, the display control unit 116 may display the icon at the change position. Alternatively, the display control unit 116 may display the icon at the change position with a certain delay time. That is, the display control unit 116 may display the icon at the change position when the estimation accuracy is low for a certain time or longer. When the estimation accuracy is increased, an icon is displayed at the vehicle position acquired by the position information acquisition unit 111.

  By doing in this way, when the estimation accuracy becomes high, a sudden change in the icon position can be suppressed. Thereby, the own vehicle position can be appropriately displayed, and the user can quickly grasp the own vehicle position. For example, even if there is a branch point immediately after the exit of the tunnel, the user can drive without confusion. Moreover, the change position should just be the vicinity of a tunnel exit and a branch point, and does not need to correspond completely with a tunnel exit and a branch point. In addition, the navigation device is not limited to that used for automobiles, and may be used for bicycles, motorcycles, etc.

  In addition, the plurality of examples described above can be implemented in combination as appropriate. For example, the change position may be changed according to the time when the estimation accuracy is low while passing through a high-rise building group.

  In the above embodiment, each element described in the drawings as a functional block for performing various processes can be configured by a CPU, a memory, and other circuits in terms of hardware, and in terms of software, This is realized by a program loaded in the memory. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof, and is not limited to any one.

  Further, the above program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Compact Disc-Read Only Memory), CDs. -R (CD-Recordable), CD-R / W (CD-ReWritable), semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)) Including. Further, the program may be supplied to the computer by various types of temporary computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

DESCRIPTION OF SYMBOLS 100 Navigation apparatus 110 Control part 111 Position information acquisition part 112 Estimate precision determination part 113 Operation reception control part 114 Map information acquisition part 115 Identification part 116 Display control part 120 GPS apparatus 130 Operation part 140 Storage part 150 Display part

Claims (5)

Based on the positioning signal from the satellite, a position information acquisition unit that acquires the vehicle position;
An estimation accuracy determination unit that determines whether or not the estimation accuracy of the vehicle position in the position information acquisition unit is low;
Based on the traveling path and traveling direction of the vehicle on the map information, a specifying unit that specifies a change position where the estimation accuracy is assumed to be high,
And a display control unit configured to change a display position of the vehicle on the map information so as to indicate the change position when it is determined that the estimation accuracy is low.   The navigation device according to claim 1, wherein the change position is specified as a tunnel exit when the host vehicle is traveling in a tunnel.   The navigation device according to claim 1, wherein the change position is specified as a next branch point on the travel path. Acquiring a vehicle position based on a positioning signal from a satellite;
Determining whether the estimation accuracy of the vehicle position is low;
Identifying a change position where the estimation accuracy is assumed to be high based on the traveling path and traveling direction of the vehicle on map information;
And changing the display position of the vehicle on the map information to indicate the changed position when it is determined that the estimation accuracy is low. Acquiring a vehicle position based on a positioning signal from a satellite;
Determining whether the estimation accuracy of the vehicle position is low;
Identifying a change position where the estimation accuracy is assumed to be high based on the traveling path and traveling direction of the vehicle on map information;
When it is determined that the estimation accuracy is low, the display position of the vehicle on the map information is changed to indicate the change position;
A program that causes a computer to execute.

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