JP2010091582A - Navigation system and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system and computer program capable of reducing both the processing load of a CPU and required memory capacity in relation to POI (point of interest) search. <P>SOLUTION: When a map image of the vicinity of the position of one's own vehicle is three-dimensionally displayed on a liquid crystal display 17, all the types of points in areas in the vicinity of the position of the own vehicle are searched to retrieve POI within a first search range within a first search distance from the current position of the own vehicle, and only specific types of points in areas remote from the position of the self vehicle are searched to retrieve POI within a second search range within a second search distance from a second search point. Icon figures indicating the types and positions of points are superimposed and displayed on the map image based on the retrieved POI. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a navigation apparatus and a computer program for searching and guiding information related to points around a reference position.

  2. Description of the Related Art In recent years, a navigation device is often mounted on a vehicle that provides vehicle travel guidance so that a driver can easily arrive at a desired destination. Here, the navigation device detects the current position of the vehicle by a GPS receiver or the like, acquires map data corresponding to the current position through a recording medium such as a DVD-ROM or HDD or a network, and displays it on a liquid crystal monitor. It is a device that can do. Further, in such a navigation device, an icon indicating a point on a map image is used to guide point information (POI: Point of Interest) such as the type and position of a point (facility etc.) around the current position of the vehicle. The drawing is also done.

  For example, in Japanese Patent Application Laid-Open No. 2005-10091 and Japanese Patent Application Laid-Open No. 2007-139931, the position of a point (facility) is displayed on a map image displayed on a display in 2D or 3D in a form corresponding to the positional relationship on the map. A technique for displaying an icon indicating a type is described.

JP 2005-10091 (pages 6 to 8, FIG. 4) JP 2007-139931 A (page 9, page 10, FIG. 7)

  Here, in order to perform POI guidance as in the techniques described in Patent Document 1 and Patent Document 2, the POI stored DB is searched, and only POIs related to points in the vicinity of the host vehicle are searched. Need to be sorted and acquired. Here, conventionally, when searching for POI, a range within a predetermined distance centered on the vehicle position (that is, the inside of a circle centered on the vehicle position and having a radius of a predetermined distance (for example, 500 m)). The search range. The search range needs to be a range including at least a map area to be displayed on the display (hereinafter referred to as a display target area). The display target area is determined based on the current position of the vehicle and the scale of the map image displayed on the display. For example, if the display target area 102 is an area surrounded by a substantially rectangular shape around the vehicle position 101 as shown in FIG. 8, the search range 103 has a size that surrounds at least the display target area 102 with the vehicle position 101 as the center. It needs to be a yen.

  In recent navigation apparatuses, a map image to be displayed on a display is displayed in 3D display as in Patent Document 2 described above. And when performing a map image by 3D display, the display object area used as the display object on a display becomes large compared with the case where it performs by 2D display even if it is the same scale. Here, FIG. 9 is a diagram showing the display target area 112 when 3D display is performed at the same scale and the same vehicle position 101 as in FIG. As shown in FIG. 9, the display target area 112 when performing 3D display is very large compared to the display target area 102 when performing 2D display. In addition, the display target area 112 has a substantially trapezoidal shape because the area farther from the vehicle position 101 needs to have a wider width. Therefore, the search range 113 surrounding the display target area 112 needs to be very large compared to the search range 103 when performing 2D display.

  Further, in recent years, when a map image is displayed by 3D display, it has been proposed that an area farther from the own vehicle position is a display target area in order to bring the map image closer to an actual field of view. Therefore, it has become necessary to further expand the search range for searching for POI. Here, in the process of searching for POI, the processing load on the CPU and the required memory capacity vary greatly depending on the size of the search range. That is, when the search range is widened, the processing load on the CPU increases and the required memory capacity also increases.

  Patent Document 1 describes a technique for reducing the number of POI icons displayed on a display. However, since the POI search is performed within the same search range as before, the processing load on the CPU has not been sufficiently reduced.

  The present invention has been made to solve the above-described problems, and even when a POI search is performed for a wide area or a distorted area, the search range can be minimized. An object of the present invention is to provide a navigation device and a computer program capable of reducing the processing load on the CPU and reducing the necessary memory capacity.

  In order to achieve the above object, a navigation device (1) according to claim 1 of the present application includes a reference position acquisition means (13) for acquiring a reference position and a shape around the reference position acquired by the reference position acquisition means. Search range setting means (13) for setting a plurality of different search ranges, point information acquisition means (13) for acquiring information relating to points located within the plurality of search ranges set by the search range setting means, And guide means (13) for guiding information related to the spot acquired by the spot information acquisition means.

  Moreover, the navigation device (1) according to claim 2 is the navigation device according to claim 1, wherein the search range setting means (13) specifies a plurality of search points located around the reference position. A point specifying unit (13) and a distance associating unit (13) for associating different search distances for each of the search points with the plurality of search points specified by the search point specifying unit. And a range within the search distance associated with the search point is set as the search range.

  Further, the navigation device (1) according to claim 3 is the navigation device according to claim 2, wherein the distance associating means (13) is located at a first search point whose distance from the reference position is a first distance. A first search distance is associated with the second search point, and a second search distance shorter than the first search distance is associated with a second search point whose distance from the reference position is a second distance that is longer than the first distance. And

  Further, the navigation device (1) according to claim 4 is the navigation device according to claim 3, wherein the point information acquisition means (13) is within a second search range centered on the second search point. Of the information about the points, only the information about the specific type of points is acquired.

  Further, the navigation device (1) according to claim 5 is the navigation device according to any one of claims 1 to 4, further comprising a traveling direction prediction means (13) for predicting a traveling direction of the host vehicle, The point information acquisition means (13) obtains information preferentially from information regarding a point in the search range located in the traveling direction of the host vehicle predicted by the traveling direction prediction means among the plurality of search ranges. It is characterized by.

  Further, the navigation device (1) according to claim 6 is the navigation device according to any one of claims 1 to 5, wherein the guide means (13) is acquired by the point information acquisition means (13). An icon for specifying the position and type of the image is displayed on the map image.

  Further, the computer program according to claim 7 is installed in a computer, and the vehicle position acquisition function (S1) for acquiring the current position of the vehicle, and the current position of the vehicle acquired by the vehicle position acquisition function. A search range setting function (S1, S2, S4, S5) for setting a plurality of search ranges having different shapes in the surroundings, and information on points located within the plurality of search ranges set by the search range setting function is acquired. A point information acquisition function (S3, S8) and a guidance function (S9) for guiding information related to the point acquired by the point information acquisition function are executed.

  According to the navigation device according to claim 1, having the above-described configuration, even when searching for information regarding a point in a wide area or a distorted area of a shape, the search is performed using a plurality of search ranges having different shapes. By doing so, the search range can be minimized. Therefore, it is possible to reduce the processing load on the CPU and reduce the necessary memory capacity.

  According to the navigation device of claim 2, when the search range is circular, by specifying a plurality of central points, a search range with a new shape combining a plurality of circular search ranges. , You can search for information about points. Therefore, even when searching for information about a point in an area with a distorted shape, the search range can be minimized.

  Further, according to the navigation device of the third aspect, the circular search range for searching an area far from the reference position is made smaller than the search range for searching an area near the reference position. In particular, when searching for a substantially trapezoidal area to be displayed on the display when performing 3D display, the search range can be minimized.

  According to the navigation device of the fourth aspect, when searching for an area far from the reference position, only information related to a specific type of point is searched, so that the search range is wide and the vicinity of the reference position In a distant area where there is less necessity for guiding information related to the point, it is possible to search only a specific point serving as a mark of the traveling direction of the vehicle in advance.

  Further, according to the navigation device of the fifth aspect, based on the predicted traveling direction of the own vehicle, information related to the spot is preferentially searched from an area that is highly necessary to be guided in the future, and the information is guided to the user. It becomes possible. Therefore, even when it is necessary for the CPU search processing for a long time, it is possible to provide appropriate guidance regarding the point.

  Further, according to the navigation device of the sixth aspect, since the information about the point is guided by displaying the icon on the map image, the user can easily grasp the information about the point at a glance. .

  Further, according to the computer program of the seventh aspect, even when a search for information on a point is performed for a wide area or a distorted area of the shape, the search is performed by a plurality of search ranges having different shapes. Thus, the search range can be minimized. Therefore, it is possible to reduce the processing load on the CPU and reduce the necessary memory capacity.

It is the block diagram which showed the navigation apparatus which concerns on this embodiment. It is the figure which showed an example of the point memorize | stored as POI. It is the figure which showed an example of the icon figure memorize | stored as POI and a search condition. It is a flowchart of the point information guidance processing program which concerns on this embodiment. It is the figure which showed an example of the search method of POI. It is the figure which showed an example of the setting method of the search order of a 2nd search range. It is the figure which showed the driving guidance screen displayed on a liquid crystal display in the navigation apparatus which concerns on this embodiment. It is the figure which showed the display object area in the case of displaying a map image by 2D display. It is the figure which showed the display object area in the case of displaying a map image by 3D display.

  DETAILED DESCRIPTION Hereinafter, a navigation device according to the present invention will be described in detail with reference to the drawings based on a specific embodiment. First, a schematic configuration of the navigation device 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a navigation device 1 according to this embodiment.

  As shown in FIG. 1, the navigation apparatus 1 according to the present embodiment is based on a current position detection unit 11 that detects the current position of the vehicle, a data recording unit 12 that records various data, and input information. The navigation ECU (reference position acquisition means, search range setting means, point information acquisition means, guidance means, search point identification means, distance association means, travel direction prediction means) 13 that performs various arithmetic processes, and from the operator From an operation unit 14 that receives an operation, an information output unit 15 that outputs various information related to map information, guidance routes, POI guidance, and the like, and a communication module 16 that communicates with an information center such as a traffic information center It is configured. The POI refers to digital content data linked with location information such as facility information and spot information.

Below, each component which comprises the navigation apparatus 1 is demonstrated in order.
The current position detection unit 11 includes a GPS 31, a geomagnetic sensor 32, a vehicle speed sensor 33, a steering sensor 34, a gyro sensor 35, an altimeter (not shown), and the like. Can be detected. Here, in particular, the vehicle speed sensor 33 is a sensor for detecting a moving distance and a vehicle speed of the vehicle, generates a pulse according to the rotation of the wheel of the vehicle, and outputs a pulse signal to the navigation ECU 13. And navigation ECU13 calculates the rotational speed and moving distance of a wheel by counting the pulse which generate | occur | produces. Note that the navigation device 1 does not have to include all of the above five types of sensors, and the navigation device 1 may include only one or more of these types of sensors.

  The data recording unit 12 is a driver for reading out an external storage device and a hard disk (not shown) as a recording medium, a map information DB 22 recorded on the hard disk, a predetermined program, etc. and writing predetermined data on the hard disk. And a recording head (not shown).

  Here, the map information DB 22 stores various map data necessary for route guidance, traffic information guidance, and map display. Specifically, link data 24 relating to a road (link) shape, node data 25 relating to node points, POI data 26 which is information relating to points such as facilities, search data for searching for a route, intersection data relating to each intersection, points Search data for searching for images, maps, roads, image information such as traffic information, etc. are drawn on the liquid crystal display 17.

  Here, as the link data 24, for each link constituting the road, the link length, the width of the road to which the link belongs, the gradient, the cant, the bank, the road surface state, the number of road lanes, and the number of lanes decrease. The data representing the location, the width-decreasing location, the level crossing, etc., for the corner, the data representing the radius of curvature, the intersection, the T-junction, the entrance and the exit of the corner, etc. Regarding the road type, in addition to general roads such as national roads, prefectural roads and narrow streets, data representing toll roads such as national highways, urban highways, general toll roads, and toll bridges are recorded. Furthermore, regarding toll roads, data relating to entrance roads (rampways), toll gates (interchanges) and the like of toll roads are recorded.

  Further, as the node data 25, actual road branch points (including intersections, T-junctions, etc.), node point coordinates (positions) set for each road according to a curvature radius, etc. Node attribute indicating whether a node is a node corresponding to an intersection, etc., a connection link number list that is a list of link numbers of links connected to the node, and an adjacency that is a list of node numbers of nodes adjacent to the node via the link Data relating to the node number list, the height (altitude) of each node point, and the like are recorded.

Further, as the POI data 26, information relating to a point that becomes a departure point, a destination, a passing point, etc. in the navigation processing of the navigation device 1 is stored. For example, accommodation facilities such as hotels and inns, refueling facilities such as gas stations, commercial facilities such as shopping malls, supermarkets, shopping centers, entertainment facilities such as theme parks and game centers, eating and drinking facilities such as restaurants, bars and taverns, and public facilities Parking facilities such as parking lots, transportation facilities, religious facilities such as temples and churches, public facilities such as museums and museums, historic sites, tourist spots, viewpoints (scenic spots), plazas, intersections, public buildings Information on points such as monuments.
Further, the POI data 26 indicates a type such as a POI number that is an identifier of the point, a POI name indicating the name of the point, and a type of the point (“parking lot”, “post office”, “restaurant”, etc.). The POI type, the POI coordinates indicating the coordinates of the point, and the like are stored. Here, FIG. 2 is a diagram showing an example of information regarding points stored as the POI data 26.
For example, the example of the POI data 26 shown in FIG. 2 indicates that a station XX corresponding to the POI number “10001” is installed at a point of coordinates (x1, y1). Further, it is shown that a parking lot corresponding to POI number “10002” is installed at the point of coordinates (x2, y2). Similarly, information on other points is also stored.

  In addition, as the POI data 26, icon figures displayed on the liquid crystal display 17 for specifying the type and position of the POI and data related to the search conditions are also stored. For example, in FIG. 3, as the types of points, icon figures corresponding to “airport”, “station”, “shopping center”, “hospital”, “gas station”, “convenience store” and search conditions corresponding to each type are shown. FIG. The search condition for searching for POI is “neighbor search condition” used when searching for an area near the current position of the own vehicle and “searching for an area far from the current position of the own vehicle”. There are two types of “distant search conditions”, and only POIs of a type corresponding to the conditions are searched as described later. Each search condition will be described in detail later.

  And the navigation apparatus 1 which concerns on this embodiment searches the point located in the periphery of the present position of the own vehicle using the said POI data 26, and acquires the information regarding a corresponding point from map information DB22. Then, by displaying an icon figure at the corresponding position of the map image displayed on the liquid crystal display 17, the type and position of the spot are guided to the user.

  Further, the navigation ECU (Electronic Control Unit) 13 searches for points around the vehicle position, guidance route setting processing for setting a guide route from the current position to the destination when the destination is selected. It is an electronic control unit that performs overall control of the navigation device 1 such as POI guidance processing that guides points based on search results. The CPU 41 as the arithmetic device and the control device, the RAM 41 that is used as a working memory when the CPU 41 performs various arithmetic processes, and stores the route data when the route is searched, and the navigation device 1 are provided. In addition to a ROM 43 that records programs for controlling various devices, a program read from the ROM 43, an internal storage device such as a flash memory 44 that records a POI guidance processing program (see FIG. 4) and the like is provided.

  The operation unit 14 is operated, for example, when inputting a destination as a guidance end point, and includes a plurality of operation switches (not shown) such as various keys and buttons. Then, the navigation ECU 13 performs control to execute various corresponding operations based on switch signals output by pressing the switches. In addition, it can also be comprised with the touchscreen provided in the front surface of the liquid crystal display 17. FIG. The operation unit 14 may also be used for inputting a departure place as a guidance start point.

  The information output unit 15 includes a liquid crystal display 17, a speaker 18, and the like, and outputs various information related to a map, guidance route, and POI around the vehicle to the user.

  Here, the liquid crystal display 17 constituting the information output unit 15 is provided on the center console or the panel surface of the vehicle interior, and includes a map image including a road, traffic information, operation guidance, operation menu, key guidance, and current position. The guide route to the destination, guide information along the guide route, news, weather forecast, time, mail, TV program, etc. are displayed. When displaying a map image, an icon graphic indicating the type and position of the POI in the display target area of the map is superimposed on the map image based on the POI data 26 and displayed.

  In addition, the speaker 18 constituting the information output unit 15 outputs voice guidance for guiding traveling along the guidance route and traffic information guidance based on an instruction from the navigation ECU 13.

  In addition, the communication module 16 includes information such as traffic jam information, regulation information, parking lot information, and traffic accident information transmitted from a traffic information center such as a VICS (registered trademark: Vehicle Information and Communication System) center or a probe center. For example, a mobile phone or a DCM is applicable.

  Further, the navigation device 1 may be provided with a DVD drive. A DVD drive is a drive that can read data recorded on a recording medium such as a DVD or a CD. The map information DB 22 is updated based on the read data.

  Next, a POI guidance processing program executed by the CPU 41 in the navigation device 1 having the above configuration will be described with reference to FIG. FIG. 4 is a flowchart of the POI guidance processing program according to this embodiment. Here, the POI guidance processing program is executed at predetermined intervals (for example, every 200 ms) after the ACC of the vehicle is turned on, and searches for points (facility etc.) around the own vehicle position and relates to the points based on the search results. It is a program that guides information. Note that the program shown in the flowchart of FIG. 4 below is stored in the RAM 42 or ROM 43 provided in the navigation apparatus 1 and is executed by the CPU 41.

  First, in step (hereinafter abbreviated as S) 1 in the POI guidance processing program, the CPU 41 acquires the current position of the vehicle as a reference position for guiding surrounding map information. Specifically, first, the current position of the own vehicle is detected by the GPS 31, and the map matching process for specifying the current position of the own vehicle on the map from the map information stored in the map information DB 22 is performed. As will be described later, the current position of the host vehicle is the center of the POI search range (first search range) in the display target area, particularly in the area near the current position of the host vehicle (area 54 shown in FIG. 5). It becomes a point (first search point). In S1, the current position of the host vehicle is acquired as the reference position. However, any point on the map other than the current position of the host vehicle may be used as the reference position. For example, when the user performs a map scrolling operation or the like on the map screen, an arbitrary point based on the user's operation is acquired as the reference position. Further, S1 corresponds to the processing of the reference position acquisition unit.

  Next, in S2, the CPU 41 associates the first search distance with the current position (first search point) of the host vehicle. Here, the first search distance is one of the parameters for setting a first search range for searching for a POI in an area near the own vehicle position with the current position of the own vehicle as the center. Specifically, a range within a first search distance from the first search point, that is, a range inside a circle centered on the first search point and having a radius as the first search distance is the first search range. In the present embodiment, the first search distance is, for example, 2/3 of the total length L (see FIG. 5) along the traveling direction of the host vehicle in the display target area.

  Then, by performing the process of S2, a first search range that is a range in which POI is searched in the area near the vehicle position (area 54 shown in FIG. 5) is set. For example, if a substantially trapezoidal area around the current position 51 of the host vehicle is a display target area 52 to be displayed on the liquid crystal display 17 as shown in FIG. 5, the first search range 53 is the current position of the host vehicle. This is the inner range of a circle having a radius (2/3) L with 51 as the center. By setting the first search range 53, it is possible to search for POIs located in the display target area 52, particularly in the area 54 near the vehicle position.

Subsequently, in S3, the CPU 41 searches for a POI located within the first search range set in S2, and acquires information regarding the point from the map information DB 22. Specifically, based on the POI data 26 (see FIG. 2) stored in the map information DB 22, a point located within the first search range is specified, and information regarding the specified point is acquired from the map information DB 22. .
Further, the POI to be searched at that time differs depending on the “point type” and the “scale of the map displayed on the liquid crystal display 17”. For example, as shown in FIG. 3, the POI of “airport” is a search target only when the scale is 10 m to 10 km. Further, the POI of “station” is a search target only when the scale is 10 m to 5 km. In addition, POIs of “shopping center” and “hospital” are subject to search only when the scale is 10 m to 2 km. Further, POIs of “gas station” and “convenience store” are searched only when the scale is 10 m to 400 m. As a result, POIs of a type having a large number of installations and having too many corresponding points in a large scale map can be excluded from the search target in advance.

  Thereafter, in S4, the CPU 41 specifies the second search point. As will be described later, the second search point is a central point of a range (second search range) in which the POI is searched in an area far from the own vehicle position (area 55 shown in FIG. 5). Become. Note that the position of the specified second search point varies depending on the shape of the display target area, and includes an area far from the own vehicle position (area 55 shown in FIG. 5) by the second search range set in S5 described later. One or more are identified at possible positions. In the example illustrated in FIG. 5, the second search points are specified as five points A to E.

  Next, in S5, the CPU 41 associates the second search distance with the second search point specified in S4. Here, the second search distance is a parameter for setting a second search range for searching for a POI in an area far from the vehicle position centering on the second search point. Specifically, a range within the second search distance from the second search point, that is, a range inside a circle centered on the second search point and having a radius as the second search distance is the second search range. In the present embodiment, the second search distance is, for example, ¼ of the total length L (see FIG. 5) along the traveling direction of the host vehicle in the display target area.

  Then, by performing the process of S5, a second search range that is a range for searching for POI in an area far from the vehicle position (area 55 shown in FIG. 5) is set. For example, as shown in FIG. 5, if a substantially trapezoidal area around the current position 51 of the host vehicle is set as a display target area 52 to be displayed on the liquid crystal display 17, the second search ranges 56 to 60 are each second search ranges 56 to 60. It is a range inside each circle of radius (1/4) L centering on the search points A to E. Then, by setting the second search ranges 56 to 60, it is possible to search for the POI located in the display target area 52, particularly in the area 55 far from the vehicle position. Note that S1, S2, S4, and S5 correspond to the processing of the search range setting means, S1 and S4 correspond to the processing of the search point specifying means, and S2 and S5 correspond to the processing of the distance association means.

  Thereafter, in S6, the CPU 41 predicts a future traveling direction of the vehicle. The traveling direction of the host vehicle is predicted according to the guidance route when a guidance route is set in the navigation device 1. Further, when the guide route is not set, the prediction is made on the assumption that the vehicle travels along the road on which the vehicle is currently traveling. Note that S6 corresponds to the process of the traveling direction predicting means.

  Next, in S7, the CPU 41 sets the search order of the second search range set in S5 based on the prediction result of the traveling direction of the host vehicle in S6. Specifically, it is set so that the POI search is performed preferentially from the second search range located in the predicted traveling direction of the vehicle.

Here, a specific example of setting the search order in S7 will be described below with reference to FIG. FIG. 6 shows an example in which it is predicted that the host vehicle will travel along the route 61 thereafter.
In the example shown in FIG. 6, the own vehicle travels along the route 61 and is expected to turn in the right direction in the future. Accordingly, among the second search ranges 56 to 60, the second search ranges 59 and 60 positioned in the right direction with respect to the current traveling direction of the host vehicle have priority over the second search ranges 56 and 57 positioned in the left direction. And set the search order to search. Specifically, first, the second search range 58 positioned in the current traveling direction of the host vehicle is searched first, then the second search range 59 positioned in the right direction is searched second, and the right direction is the same. The second search range 60 located at is searched third, then the second search range 57 located in the left direction is searched fourth, and the second search range 56 also located in the left direction is searched fifth. Set the search order to As a result, it is possible to search for POIs in order from areas that are likely to be displayed on the liquid crystal display 17 in the future.

Subsequently, in S8, the CPU 41 searches for the POI located in the second search range set in 5 according to the search order set in S7, and acquires information on the corresponding POI from the map information DB 22. Specifically, based on the POI data 26 (see FIG. 2) stored in the map information DB 22, a point located within the second search range is specified, and information on the specified point (type of point and position coordinates) Etc.) from the map information DB 22.
Further, the POI to be searched at that time differs depending on the “point type” and the “scale of the map displayed on the liquid crystal display 17”. Furthermore, the POI search by the second search range is targeted only for a specific type of POI (in this embodiment, “airport” and “station”).
For example, as shown in FIG. 3, the POI of “airport” is a search target only when the scale is 10 m to 6 km. The POI of “station” is a search target only when the scale is 10 m to 3 km. The other types of POIs are not searched. As a result, in a distant area where the search range is wide and there is less need for guidance regarding information about the location than in the vicinity of the host vehicle position, only a specific POI that serves as a mark of the traveling direction of the host vehicle is searched in advance. It becomes possible. In addition, said S3, S8 is corresponded to the process of a point information acquisition means.

  Thereafter, in S9, the CPU 41 displays the searched POI on the liquid crystal display 17 based on the search results of S3 and S8. Specifically, an icon graphic (FIG. 3) corresponding to the searched POI type is displayed at a position corresponding to the POI position coordinates. Further, the size of the icon graphic to be displayed differs depending on the distance from the current position of the own vehicle to the POI, and the point located farther is set to a smaller size.

Here, FIG. 7 is a diagram showing a travel guidance screen 71 displayed on the liquid crystal display 17 in the navigation device 1 according to the present embodiment.
As shown in FIG. 7, the travel guidance screen 71 includes a vehicle position mark 72 indicating the current position of the vehicle, a map image 73 displayed in 3D, and icon graphics 74 to 85 drawn on the map image 73. Consists of

  In addition, the sizes of the icon figures 74 to 85 change depending on the line (the squares counted from the front) including the POI position coordinates. Specifically, the POI icon figures 74 to 76 located in the first to third lines are displayed in the largest size, and the POI icon figures 77 to 82 located in the fourth to seventh lines are second. The POI icon figure 83 positioned in the 8th to 10th lines is displayed in the third largest size, and the feature icon figures 84 and 85 located in the 11th to 12th lines. Is displayed in the smallest size. The areas in the first to seventh lines shown in FIG. 7 correspond to the area in the vicinity of the own vehicle position (area 54 shown in FIG. 5) for all types of POI, and the areas in the eighth to twelfth lines are specified. This corresponds to an area far from the own vehicle position (area 55 shown in FIG. 5) where only the type of POI is searched.

  Therefore, the user can grasp the type of POI (convenience store, gas station, etc.) and position around his / her vehicle by referring to the travel guidance screen 71 displayed on the liquid crystal display 17. Further, the approximate distance to the POI can be grasped based on the size of the icon graphic. Furthermore, since only the icon graphic of a specific POI (airport or station) is displayed in an area far from the vehicle position, there is less possibility of the icon graphic overlapping with each other in the remote area. Furthermore, it is possible to confirm the direction of the host vehicle based on the displayed specific POI icon graphic. Note that S9 corresponds to the processing of the guide means.

  Next, in S10, the CPU 41 determines whether or not there is a second search range in which POI is not searched. As a result, when it is determined that there is an unsearched second search range (S10: YES), the process returns to S8, the remaining second search range is searched according to the search order, and information regarding the location is obtained from the map information DB 22. get. Similarly, the retrieved POI is displayed on the liquid crystal display 17.

  On the other hand, when it is determined that there is no second search range in which POI has not been searched (S10: NO), the POI guidance processing program is terminated.

As described in detail above, in the navigation device 1 according to the present embodiment, the point information guidance method by the navigation device 1 and the computer program executed by the navigation device 1, a map image around the vehicle position is displayed on the liquid crystal display, particularly by 3D display. 17, for areas near the own vehicle position, all types of POIs are searched, and POIs in the first search range within the first search distance from the current position of the own vehicle are searched (S1 to S3). ) In the area far from the vehicle position, a POI in the second search range within the second search distance from the second search point is searched for only a specific type of point as a search target (S4 to S8), and the searched POI The icon figure indicating the type and position of the point is displayed superimposed on the map image based on the map (S9). Even when searching the POI rear as the target, it is possible to minimize the search range. Therefore, it is possible to reduce the processing load on the CPU in the POI search and to reduce the necessary memory capacity.
In addition, when the search range is circular, by specifying a plurality of central points, it is possible to search for information about the points by using a new shape search range that combines a plurality of circular search ranges. Therefore, even when a POI search is performed for an area with a distorted shape, the search range can be minimized.
In addition, the circular search range for searching an area far from the current position of the host vehicle is made smaller than the search range for searching an area near the current position of the host vehicle. In addition, when searching for a substantially trapezoidal area to be displayed on the display, the search range can be minimized.
In addition, when searching for an area far from the current position of the vehicle, only information about a specific type of point is searched, so the information about the point is wider than the vicinity of the vehicle position and the search range is wide. In a distant area where there is little need for the vehicle, only a specific POI that serves as a mark in the traveling direction of the host vehicle can be searched in advance.
Based on the predicted traveling direction of the own vehicle, it is possible to search for information about a point with priority from an area that needs to be guided in the future, and to guide the user. Therefore, even when it is necessary for the CPU search processing for a long time, it is possible to provide appropriate guidance regarding the point.
Furthermore, since the information regarding the point is guided by displaying the icon graphic on the map image, the user can easily grasp the information regarding the point at a glance.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the first search distance and the second search distance that define the POI search range are set based on the total length L (see FIG. 5) of the display target area, but may be fixed values.

  In the present embodiment, the area far from the vehicle position (area 55 shown in FIG. 5) is configured to search only for a specific type of POI (airport or station). You may comprise so that a user can select the kind of POI made into object. Also, an area near the vehicle position (area 54 shown in FIG. 5) may be searched for only a specific type of POI.

1 Navigation device 13 Navigation ECU
15 Liquid crystal display 16 Speaker 22 Map information DB
26 POI data 41 CPU
42 RAM
43 ROM
53 First search range 56-60 Second search range

Claims (7)

A reference position acquisition means for acquiring a reference position;
Search range setting means for setting a plurality of search ranges having different shapes around the reference position acquired by the reference position acquisition means;
Point information acquisition means for acquiring information on points located within a plurality of search ranges set by the search range setting means;
A navigation device comprising guidance means for guiding information related to the spot acquired by the spot information acquisition means. The search range setting means includes
Search point specifying means for specifying a plurality of search points located around the reference position;
Distance associating means for associating different search distances for each search point with the plurality of search points specified by the search point specifying unit;
With
The navigation device according to claim 1, wherein a range within the search distance associated with the search point is set as the search range with the search point as a center. The distance association means includes
Associating a first search distance with a first search point whose distance from the reference position is the first distance;
3. The navigation according to claim 2, wherein a second search distance shorter than the first search distance is associated with a second search point having a second distance far from the first distance from the reference position. apparatus.   The said point information acquisition means acquires only the information regarding the specific classification point among the information regarding the said point within the 2nd search range centering on the said 2nd search point. Navigation device. It has a traveling direction prediction means for predicting the traveling direction of the own vehicle,
The point information acquisition means preferentially acquires information on a point in a search range located in the traveling direction of the host vehicle predicted by the traveling direction prediction unit among the plurality of search ranges. The navigation device according to any one of claims 1 to 4.   The navigation apparatus according to claim 1, wherein the guide unit displays an icon for specifying the position and type of the spot acquired by the spot information acquisition unit on a map image. On the computer,
A reference position acquisition function for acquiring a reference position;
A search range setting function for setting a plurality of search ranges having different shapes around the reference position acquired by the reference position acquisition function;
A point information acquisition function for acquiring information related to points located within a plurality of search ranges set by the search range setting function;
A guidance function for guiding information about the spot acquired by the spot information acquisition function;
A computer program for executing

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