JP2008096209A - Reachable range display device, and reachable range display method and program thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability, high-visibility reachable range display device for superimposedly displaying the range on a map image that can be reached within a prescribed time. <P>SOLUTION: The reachable range display device displays a range that can be reached within a prescribed time from a reference point on a map on a map image. The reachable range display device has a search section, an image generation section, an image processing section, and an image superimposing section. The search section searches for optimum path, from a reference point to a plurality of arbitrary points on an arbitrary map image, to calculate the required time. The image-generating section generates a first image, capable of distinguishing a group of points that can be reached from a group of points that cannot be reached within a prescribed time searched by the search section. The image processing section generates a second image, showing the range that can be reached from the reference point within a prescribed range, from the first image generated by the image generation section. The image-superimposing section superimposes the second image generated by the image processing section on the map image for displaying on a display screen. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reachable range display device, a reachable range display method, and a program therefor, and more specifically, a mobile object arrives on a map image within a predetermined time from a predetermined position (for example, current position). The present invention relates to a reachable range display device that superimposes and displays an image showing a possible range, a reachable range display method, and a program thereof.

  2. Description of the Related Art Conventionally, a technology relating to a reachable range display device that displays a range in which a moving body can reach within a certain time from a reference point (for example, the current position of a vehicle) has been disclosed (for example, see Patent Document 1). This reachable range display device is used in a vehicle allocation / command system in a taxi, a security company, etc., and can display and manage the vehicle appropriately and optimally allocate and command the vehicle.

In addition, according to the navigation device to which the reachable range display device is applied, an intersection that can be reached within a certain time from the current position of the vehicle is searched, and the direction is divided from the current position of the vehicle as a center. For each area, the intersection farthest from the current position of the vehicle is extracted as a display node. Furthermore, it is possible to superimpose and display a line (closed curve) connecting the display nodes extracted for each divided region on the map image.
JP-A-11-16094

  However, in the conventional reachable range display device described in Patent Document 1, before searching for the intersection farthest from the current position of the vehicle, for each area obtained by dividing the direction around the current position of the vehicle, The number of directions the user divides is divided into a plurality of directions around the current position of the vehicle. In this case, there is a problem that it is necessary for the user to set the number of divisions in advance, and it takes time to operate the system.

  Further, when the number of divisions for dividing the azimuth around the current position of the vehicle is a small value (for example, 4 or 8), a closed curve indicating a range that can be reached at high speed is superimposed and displayed on the map image. Can do. In this case, there is a problem that the reliability of the reachable range is lowered. Here, the reduction in reliability means that an out-of-time node (intersection that cannot actually be reached) is included in the reachable range. In other words, when connecting nodes extracted for each division, nodes outside the time (intersections that cannot actually be reached) will be included in the range surrounded by each node, and reachable that is displayed in a superimposed manner The reliability of the range was lowered, which was inconvenient for the user.

  In addition, when the number of divisions is a large value, nodes that can be reached within a predetermined time are extracted. Therefore, the shape indicating the reachable range is not a smooth closed curve but a closed curve and poor visibility. Had the problem.

  Therefore, the present invention provides a reachable range display device and a reachable range display method capable of showing a reachable range with high reliability and visibility without setting how many divisions the user should divide in advance. The purpose is to provide the program.

In order to achieve the above object, the present invention employs the following configuration.
1st invention is the reachable range display apparatus which displays the range which can be reached within the predetermined time from the reference point on a map on a map image. The reachable range display device includes a search unit, an image generation unit, an image processing unit, and an image superimposing unit. A search part searches for the optimal path | route from the reference point to arbitrary several points on arbitrary map images, and calculates required time. An image generation part produces | generates the 1st image which can distinguish the point group which can be reached within the predetermined time searched by the search part, and the point group which cannot be reached. The image processing unit generates a second image indicating a reachable range within a predetermined time from the reference point from the first image generated by the image generation unit. The image superimposing unit superimposes the second image generated by the image processing unit on the map image and displays it on the display screen.

  In a second aspect based on the first aspect, the image generation unit generates a first image in which a point group that can be reached within a predetermined time searched for by the search unit from the reference point is indicated by a predetermined color. The image processing unit generates a second image indicating a reachable range within a predetermined time from the reference point from the first image indicated by the predetermined color.

  In a third aspect based on the second aspect, the image generation unit uses pixels of a predetermined color around each pixel indicating a point group that can be reached within a predetermined time searched by the search unit from the reference point. A fattened first image is generated.

  In a fourth aspect based on the second aspect, the image generation unit searches for a point group that can be reached within a predetermined time from the reference point by the search unit. The pixels at the boundary with the point group that cannot be reached within the predetermined time are fattened with a predetermined color only on the respective reference point side, and pixels other than the boundary are fattened with pixels of the predetermined color around each of the reference points. A first image is generated.

  In a fifth aspect based on the second aspect, the image generation unit is indicated by a predetermined color using a route from the reference point to each of the points that can be reached within a predetermined time searched by the search unit. A first image is generated.

  In a sixth aspect based on the fifth aspect, the image generation unit determines a thickness for filling the route with a predetermined color based on the road type of the route.

  In a seventh aspect based on the first aspect, the image generation unit fills an area on the map including all reachable point groups in the first color with the first color, The image processing apparatus includes a contour extracting unit that generates an image filled with a second color different from the first color and extracts a contour curve that is a boundary between the first color and the second color. The image superimposing unit superimposes the contour curve on the map image and displays it on the display screen.

  In an eighth aspect based on the seventh aspect, the contour extracting section extracts the boundary between the first color and the second color, with the first color being black and the second color being white.

  In a ninth aspect based on the seventh aspect, the contour extracting unit extracts a contour curve using a predetermined dynamic contour model.

  In a tenth aspect based on the ninth aspect, the search unit uses a circular area centered on the reference point and whose radius is a predetermined distance as a search range, and an arbitrary area existing in the search range from the reference point. The optimum time to a plurality of points is searched and the required time is calculated. The contour extraction unit sets the circular region used by the search unit as a curve in an initial state when the dynamic contour model is used.

  In an eleventh aspect based on the third aspect, the search unit is based on the number of routes from a reference point existing in a predetermined range centered on the reference point to any plurality of points on any map image. And a road density calculation unit for calculating the road density. The image generation unit, based on the road density calculation result calculated by the road density calculation unit, based on the road density, the number of pixels that thicken pixels indicating a reachable point group with pixels of a predetermined color around each of them. decide.

  In a twelfth aspect based on the eleventh aspect, the road density calculation unit divides a predetermined range centered on the reference point into concentric or mesh-shaped areas, and routes exist for each of the divided areas. Based on the number of roads, the road density is calculated.

  In a thirteenth aspect based on the first aspect, the image generation unit generates an image indicating a reachable point group and an image indicating an unreachable point group, and a predetermined region is defined for an area where the images overlap. It includes a logical operation unit that performs a calculation and generates a first image that can distinguish between a reachable point group and an unreachable point group.

  In a fourteenth aspect based on the thirteenth aspect, the logical operation unit fills a point group that cannot be reached with the first color and sets the point group that can be reached to a second color different from the first color. To generate an image that is filled with the second color, a point group that is unreachable is filled with the second color, and an image that is a reachable point group is filled with the first color, and the logical product of the two images is used, A first image capable of distinguishing between a reachable point group and an unreachable point group is generated.

In order to achieve the above object, the present invention employs the following steps.
A fifteenth aspect of the invention is a reachable range display method for displaying a reachable range on a map image within a predetermined time from a reference point on a map. The reachable range display method includes a search step, an image generation step, an image processing step, and an image superposition step. In the search step, an optimum route from the reference point to any plurality of points on any map image is searched, and the required time is calculated. The image generation step generates a first image that can distinguish between a point group that can be reached and a point group that cannot be reached within a predetermined time searched by the search step. The image processing step generates a second image indicating a reachable range within a predetermined time from the reference point from the first image generated by the image generation step. In the image superimposing step, the second image generated in the image processing step is superimposed on the map image and displayed on the display screen.

In order to achieve the above object, the present invention employs a program that executes the following steps.
A sixteenth aspect of the invention is a reachable range display program executed by a computer of a reachable range display device that displays a reachable range on a map image within a predetermined time from a reference point on a map. The reachable range display program causes a computer to execute a search step, an image generation step, an image processing step, and an image superposition step. In the search step, an optimum route from the reference point to any plurality of points on any map image is searched, and the required time is calculated. The image generation step generates a first image that can distinguish between a point group that can be reached and a point group that cannot be reached within a predetermined time searched by the search step. The image processing step generates a second image indicating a reachable range within a predetermined time from the reference point from the first image generated by the image generation step. In the image superimposing step, the second image generated in the image processing step is superimposed on the map image and displayed on the display screen.

  According to the first aspect of the invention, the nodes indicating all intersections and / or nodes indicating the intersections that can be reached within a predetermined time from the current position of the vehicle without setting the number of divisions by the user in advance. By superimposing and displaying an image showing a link connecting the two on a map image, a reachable range with high reliability and high visibility can be shown. As a result, it is possible for the user to grasp at a glance how far and how long it can be reached.

  According to the second aspect of the present invention, since a group of spots that can be reached within a predetermined time is displayed on the map image in a superimposed manner, the visibility is high and the reachable range can be grasped at a glance. be able to.

  According to the third aspect of the invention, since the pixel indicating the point group that can be reached within the predetermined time is generated with the pixels of the predetermined color around each pixel, the point that can be reached within the predetermined time. A group can be obtained as one region.

  According to the fourth aspect of the invention, among the pixels indicating the point group that can be reached within the predetermined time, the pixels at the boundary with the point group that cannot be reached within the predetermined time are only on the reference point side. Generates an image that is fattened with a predetermined color and pixels other than the border are thickened with pixels of a predetermined color around each of them, so that it can be reached with high reliability without including points that cannot be reached within a predetermined time Range can be obtained.

  According to the fifth aspect of the invention, not only a point group that can be reached within a predetermined time but also a route to each reachable point group is used to generate an image indicated by a predetermined color. An image showing the reachable range can be obtained.

  According to the sixth aspect of the invention, since the thickness for filling the route with a predetermined color is determined based on the road type for each route, for example, the narrow street is displayed as a thicker route so that the route can be reached. It is possible to grasp at a glance.

  According to the seventh aspect, the area on the map including all reachable point groups in the map is filled with the first color, and the unreachable point group is different from the first color. An image filled with two colors is generated, a contour curve serving as a boundary between the first color and the second color is extracted, and the extracted contour curve is superimposed on the map image and displayed on the display screen.

  According to the eighth aspect of the invention, since the first color is black and the second color is white, and the boundary between the first color and the second color is extracted, the data amount is obtained by binarizing the data. Can be reduced.

  According to the ninth aspect, a contour curve can be easily extracted by using a predetermined dynamic contour model.

  According to the tenth aspect, since the circular region used by the search unit is the initial curve when using the active contour model, troublesome operations can be omitted.

  According to the eleventh aspect of the invention, the number of pixels for thickening the pixels indicating the reachable point groups with pixels of a predetermined color around each is determined based on the road density. For example, even when the road density is sparse, A point group that can be reached within a predetermined time in a short processing time can be obtained as one region.

  According to the twelfth aspect of the invention, the road density is calculated based on the number of routes existing for each region divided into concentric circles or meshes. For example, pixels that are thickened even in a region with a small number of routes. Numbers can be filled.

  According to the thirteenth aspect, an image indicating a reachable point group and an image indicating an unreachable point group are generated, a predetermined calculation is performed on a region where the images overlap, and the generated reachable Since an image that can distinguish between a point group that cannot be reached and a point group that cannot be reached is further excluded from the point group that cannot be reached, an image showing a reliable reachable range can be obtained.

  According to the fourteenth aspect, since the theoretical product is used for the predetermined calculation, it is possible to obtain an image showing a reachable range with high reliability in a short processing time.

  According to the fifteenth aspect, nodes indicating all intersections and / or nodes indicating intersections that can be reached within a predetermined time from the current position of the vehicle without setting the number of divisions by the user in advance. By superimposing and displaying an image showing a link connecting the two on a map image, a reachable range with high reliability and high visibility can be shown.

  According to the sixteenth aspect of the present invention, nodes indicating all intersections and / or nodes indicating intersections that can be reached within a predetermined time from the current position of the vehicle without setting the number of divisions by the user in advance. By superimposing and displaying an image showing a link connecting the two on a map image, a program showing a reachable range with high reliability and visibility can be provided.

(First embodiment)
With reference to FIGS. 1-18, the reachable range display apparatus which concerns on 1st Embodiment in this invention is demonstrated. In the first embodiment and the second embodiment to be described later, an example in which the reachable range display device of the present invention is applied to a navigation device mounted on a vehicle will be described. In each drawing, components not related to the present invention are omitted.

  First, a schematic configuration of the reachable range display device will be described. In FIG. 1, the navigation device 1 includes a control unit 11, a map information storage unit 12, a positioning unit 13, an input unit 14, an output unit 15, a traffic information receiving unit 16, and a working area unit 17. These units are connected by an internal bus.

  The controller 11 includes, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Moreover, the control part 11 controls operation | movement etc. of the navigation apparatus 1 whole to which the reachable range display apparatus is applied. The control unit 11 includes a search unit 111, an image generation unit 112, an image processing unit 113, and an image superimposing unit 114. Details of each unit included in the control unit 11 will be described later.

  The working area unit 17 is composed of, for example, a RAM, and the control unit 11 reads and writes data.

  The map information storage unit 12 is configured by, for example, an HDD (Hard Disc Drive) or a DVD (Digital Versatile Disc). The map information storage unit 12 stores map information such as road (link) shape data and intersection (node) position data in advance. However, the present invention is not limited to this, and the map information is appropriately downloaded from a center facility (not shown) through a communication means (not shown) (for example, a mobile phone or a PHS (Personal Handyphone System)) and stored in the map information storage unit 12. It may be a configuration.

  Here, with reference to FIG. 2A-FIG. 2C, the map information stored in the map information storage part 12 is demonstrated. The map information storage unit 12 stores, for example, node data, link data, road type data, and the like. 2A to 2C are diagrams illustrating an example of map information extracted from a part of the map information related to the present embodiment, among the map information stored in the map information storage unit 12.

  FIG. 2A is node data regarding a point (node) where a road branches in a plurality of directions such as an intersection or a junction. The node data includes position information such as latitude and longitude, the number of links connected to the node, and the link ID for each node. FIG. 2B is link data indicating a road connecting nodes. For each link, the link data indicates the start and end nodes, which are the end points of the link, the length of the link (for example, meters or kilometers), the width of the link (for example, meters, etc.), and represents the road width. ), Road types indicating general roads and highways. The link data may include information on the number of lanes or traffic restrictions. FIG. 2C is obtained by numerically adding a road type that is one of the attributes of link data. That is, each value is set for each road type such as an expressway or a general road.

  The map information storage unit 12 stores not only the above-described map information but also information such as background data indicating the ocean (hereinafter referred to as a water system) and background data indicating the land (hereinafter referred to as a land system). You may do it. Furthermore, information such as facility information that is information for managing the location of a family restaurant or a gas station may be stored.

  The positioning unit 13 detects the current position, speed, and direction of the vehicle. For example, the positioning unit 13 is a positioning sensor such as a GNSS (Global Navigation Satellite System) receiver, a vehicle speed sensor, a gyro (angular velocity) sensor, and an acceleration sensor. The GNSS receiver is, for example, a GPS (Global Positioning System) receiver that receives radio waves from a plurality of satellites and demodulates them to detect the absolute position (current position) of the receiver. Note that the positioning of the current position, speed, and direction is measured by using a GNSS receiver and various sensors alone or in combination.

  The input unit 14 includes, for example, a predetermined number of push-type switches, a remote controller, a touch panel, a voice input microphone, a voice recognition engine, and the like, and receives user instructions. The instruction input by the user includes, for example, setting of a destination, selection of a searched route, start of route guidance, switching of screen display, and the like.

  The output unit 15 includes a display device 151 that includes, for example, a liquid crystal display, a plasma display, an organic EL display, and the like, and displays information to the user. Specifically, a map image showing guidance to the destination is displayed. In addition, the output unit 15 displays an image including a closed curve indicating the reachable range extracted by the image processing unit 113 described later on the map image.

  The traffic information receiving unit 16 receives the provided traffic jam information. The traffic information receiving unit 16 is a receiving device according to the type of traffic jam information to be provided (for example, VICS information, probe information, etc.), and includes FM broadcast waves, optical / radio wave beacons, DSRC (Dedicated Short Range Communication); Band wireless communication) receivers, mobile phones and the like. For example, when the traffic information receiving unit 16 is a mobile phone, the traffic information receiving unit 16 processes highly accurate traffic jam information (for example, the position and time collected from other vehicles) after being processed. Probe information) can be received. However, the present invention is not limited to this, and the traffic jam information is a map of a predicted traffic jam database storing past traffic statistics data (for example, data representing road congestion according to past time zones, days of the week, dates, etc.). Stored in the information storage unit 12, the traffic information reception unit 16 may receive traffic jam information from the map information storage unit 12. Here, the traffic information is information indicating how much time it can pass through the section of the link length in the above-described link data, and is calculated using average speed data in the section of the link length. By using this traffic information, it is possible to determine a required time with high accuracy in consideration of the degree of congestion. In the present embodiment and the second embodiment described later, the map information storage unit 12 stores a predicted traffic jam database in advance.

  The search unit 111 determines a search condition such as a range for searching for a point (intersection) for calculating a required time and a road type of a route from a reference point to a point for calculating a required time. Based on the determined search range, road type, and the like, the search unit 111 uses a search start reference point (hereinafter, in the present embodiment and the second embodiment, the current position of the vehicle is the reference point), Calculate the required time to all points (intersections) that may travel.

  Here, the search conditions determined by the search unit 111 will be described. In a normal navigation device, the time required to reach the destination specified by the user may be calculated, and the search range is between the search start position and end position (destination). On the other hand, in the present embodiment and the second embodiment, the search unit 111 determines an appropriate search range in order to display a reachable range even when the destination is not specified by the user. . The search range is a range including at least the map area displayed on the display device 151. In the present embodiment and the second embodiment, the search range is a circle whose center is the departure point and whose radius is a fixed distance from the departure point. For example, the radius of the circle may be a value obtained by multiplying the average vehicle speed of the vehicle by the time for obtaining the reachable range. In this case, if the average vehicle speed is 500 m / min and the time for obtaining the reachable range is 10 minutes, the radius of the circle in the search range is 5000 m. Further, all nodes included in this circle are set as search targets. In a normal navigation device, a route search is performed based on the road type designated by the user. Specifically, the user performs input for designating general road priority or highway priority. On the other hand, in the present embodiment and the second embodiment, the search unit 111 determines the road type in order to display the reachable range even when the destination is not specified by the user. For example, the currently selected road type can be set as a road type to be searched. In addition, a conventional method as disclosed in Japanese Patent Application No. 2006-113168 may be used.

  In addition, the search unit 111 calculates the required time at each point by expanding the road network composed of the above-described nodes and links radially from the reference point for starting the search. At this time, when the search range is expanded radially, the search range is gradually expanded by sequentially tracing links connected to nodes to be searched (hereinafter referred to as parent nodes). Further, as a search method, a route search method represented by a known Dijkstra method can be used, but an improvement is required to increase time accuracy with respect to a link cost addition process described later. Also, the search is not stopped even if the total link cost (cumulative time) exceeds a certain time.

  The image generation unit 112 generates an image (corresponding to the first image of the present invention) that displays a position corresponding to a node and / or a link that can be reached within a certain time based on the search result by the search unit 111. Specifically, the image generation unit 112 displays a predetermined size in a first color, and a position indicating a node and / or a link that can be reached within a predetermined time on the image displayed in the first color. Is generated in the second color. The generated image is stored in the working area unit 17. In each figure used to explain the present embodiment and the second embodiment, the first color is displayed in black, and the second color is displayed in white. In the present embodiment and the second embodiment, the first color is assumed to be black and the second color is assumed to be white. Note that the first and second colors may be any color and may be a translucent color or translucent.

  The image processing unit 113 generates an image (corresponding to the second image of the present invention) indicating a range that can be reached within a predetermined time from the reference point from the first image generated by the image generation unit 112. In addition, the image processing unit 113 obtains a contour curve that serves as a boundary between the first color and the second color in the image generated by the image generation unit 112. In addition, the contour curve indicating the reachable range thus obtained is extracted in the image processing coordinate system in a direction in which the contour curve makes one round clockwise from an arbitrary position as a starting point. Here, the image processing coordinate system is a coordinate system in which the upper left corner is the origin, the right direction is the X axis, and the lower direction is the Y axis. The extracted coordinate sequence data of the contour curve (closed curve) indicating the reachable range is stored in the working area unit 17.

  The image superimposing unit 114 is an image (corresponding to the second image of the present invention) indicating a range that can be reached within a predetermined time from the reference point from the first image generated by the image generating unit 112, for example, the image processing unit 113. The contour curve (closed curve) indicating the reachable range extracted by is superimposed on the map image.

  The search unit 111, the image generation unit 112, and the image processing unit 113 may be arranged in a center facility (not shown). In this case, the navigation device 1 appropriately downloads the contour data of the reachable range from the center facility through a communication means (for example, a mobile phone) (not shown) and displays it on the display device 151.

  Next, the operation in the navigation device 1 configured as described above will be described. FIG. 3 is a flowchart showing a processing flow of the entire control unit 11.

  First, in FIG. 3, the search unit 111 determines search conditions (step S1). Subsequently, the search unit 111 performs route search processing (step S2). Subsequently, the image generation unit 112 performs image generation processing for generating an image indicating a reachable range (step S3). Subsequently, the image processing unit 113 processes the image generated by the image generation unit 112 and performs image extraction processing for extracting the outline of the reachable range (step S4). Furthermore, the image superimposing unit 114 superimposes the reachable range on the map image (step S5).

  Next, the operation of the route search process in step S2 will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the route search process.

  First, in FIG. 4, the search unit 111 determines whether all nodes that satisfy the search condition have been searched (step S <b> 21). As a result of the determination, if search unit 111 has not searched for all nodes (No in step S21), the process proceeds to step S22. On the other hand, when the search unit 111 has searched all the nodes (Yes in step S21), the route search process is terminated.

  Next, in step S22, the search unit 111 acquires a total time cost value (T1) until the parent node is reached. Subsequently, the search unit 111 acquires the link cost (cumulative time) to reach the connection destination node connected to the parent node (step S23). In subsequent step S24, the search unit 111 acquires the current time. The current time may be acquired from a GPS receiver of the positioning unit 13, for example. Subsequently, the search unit 111 adds the total time cost value (T1) until the above-mentioned acquired parent node is reached at the current time to obtain time T2 (step S25). In the following step 26, the predicted traffic jam information of the link from the parent node to the connection destination node at time T2 is requested. Subsequently, the search unit 111 acquires predicted traffic jam information from the predicted traffic jam database stored in advance in the map information storage unit 12 (step S27). Further, the search unit 111 calculates a link passage time (T3) in which the predicted congestion information acquired in step S27 is added to the link cost obtained in step S23 (step S28). Subsequently, the total time cost value (T4) until the value obtained by adding T3 to T1 is reached in the working area unit 17 (step S29). Note that, among a plurality of routes reaching a certain node, the route having the minimum total time cost value (T4) is adopted.

  In the route search process described above, the search unit 111 performs a route search in consideration of traffic jam information in a time zone in which the vehicle will pass a link from the parent node to the connection destination node. Can be explored. Even if the time for obtaining the reachable range becomes longer, the accuracy of the calculated time can be suppressed to an error within a certain range.

  Next, the operation of the image generation process in step S3 will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the image generation process.

  First, in FIG. 5, the image generation unit 112 generates an image of a predetermined size made of black (corresponding to the first color of the present invention) (step S31). Here, the predetermined size is a screen size of the display device 151 or a size slightly larger than that. In the subsequent step 32, the image generation unit 112 displays a position indicating a node and / or a link that can be reached within a predetermined time searched by the search unit 111 for the image of the predetermined size made of black as described above. (Corresponding to the second color of the present invention) (see FIG. 6 or FIG. 7). FIG. 6 is a diagram illustrating a state in which a predetermined size is painted in black and a position indicating a node that can be reached within a predetermined time is painted in white. FIG. 7 is a diagram illustrating a state in which a predetermined size is painted in black, and positions indicating nodes and links that can be reached within a predetermined time are painted in white. In addition, it is the information of the link to which the difference from FIG. 6 to FIG. 7 was added.

  Here, the filling of positions indicating nodes and / or links that can be reached within a predetermined time is performed by converting the coordinates (latitude and longitude) of the nodes into the above-described image processing coordinate system. If the converted image processing coordinates are (X, Y), the vicinity thereof (for example, the vicinity of 8 and the vicinity of 24) may be painted in white. Note that a square, a circle, an ellipse, a semicircle, or the like can be used as the shape of the vicinity. Furthermore, the number of nodes and / or links that can be reached within a predetermined time searched by the search unit 111 may be increased in white as the distance from the departure point increases. Further, the number of neighboring pixels to be painted in white may be varied according to the screen size (resolution) of the display device 151. In this case, the larger the screen size (resolution), the larger the number of neighboring pixels.

  Also, as in the example of FIG. 8, the position indicating the node that can be reached within a predetermined time is filled (pixels in the shaded area in FIG. 8), and further, all the neighborhoods thereof (for example, the neighborhood of 8 and 24) are filled. Instead, it may be painted only on the departure point side (in the direction of the dotted line arrow in FIG. 8) (pixels in the gray portion in FIG. 8; corresponding to the first color of the present invention). For example, when a node that can be reached within a predetermined time as in the example of FIG. 8 is the farthest point, the opposite side from the departure point is not included with respect to the point (the hatched pixel in FIG. 8). (Pixels in the white part of FIG. 8; corresponding to the second color of the present invention) Therefore, it is possible to obtain a region showing a reachable range with higher reliability.

  Next, with reference to FIG. 9 and FIG. 10, the operation of another image generation process for generating an image indicating a range that the image generation unit 112 can reach within a predetermined time will be described.

  First, in step S41 of FIG. 9, the image generation unit 112 generates an image of a predetermined size made of black, as in step S31 described above. Subsequently, as in the example shown in FIG. 10, the search unit 111 divides the map image concentrically around the departure point, and calculates the road density within the search range (step S42). FIG. 10 is a schematic diagram illustrating an example of a method of dividing a map image concentrically. Here, the road density is the number of nodes and / or links in one region divided concentrically. That is, when the number of nodes and / or links is less than a predetermined threshold, the road density is “sparse”, and when the number of nodes and / or links is equal to or greater than the predetermined threshold, the road density is It becomes “dense”. Note that the threshold value may be increased or decreased as the concentric circles increase. Further, the number of neighboring pixels to be painted in white may be varied based on the road type in FIG. 2C described above. For example, as the road type changes from a narrow street to a highway, the road density becomes sparse. In this case, as the road type value decreases, the number of neighboring pixels is increased.

  Subsequently, in step S43, based on the density of the road density calculated by the search unit 111, a position indicating a node and / or a link that can be reached within a predetermined time is painted in white. Here, when the road density is sparse, many neighborhoods of positions indicating nodes and / or links that can be reached within a predetermined time are painted in white. Although the map is divided concentrically around the starting point, the map is not limited to this and may be divided into a mesh shape (small rectangle). In addition, when the map image is divided into meshes, the calculated road density threshold value may be a constant value. When the map image is not divided into concentric circles or meshes, the road density may be determined from the distance between adjacent nodes. In this case, the sparser is determined as the distance between adjacent nodes is longer than a predetermined threshold.

  Next, the operation of the image extraction process in step S4 of FIG. 3 will be described with reference to FIG. FIG. 11 is a flowchart showing the operation of the image extraction process.

  First, in FIG. 11, in the image generated by the image generation processing in step S <b> 3 in FIG. 3, the black color inside the portion where the position indicating the node and / or link that can be reached within a predetermined time is displayed in white. A process of filling a gap which is a portion displayed by (Step S51) is performed. However, a node and / or link that cannot be reached within a predetermined time, that is, an area displayed in black is not a gap. Here, the process of filling the gap is a position indicating a node and / or link that can be reached within a predetermined time in white, and black between adjacent nodes and / or links displayed in white. This is a process for displaying the gap, which is the portion displayed by, in white. In addition, this process is performed by repeatedly expanding or contracting the area at the position displayed in white. Specifically, as in the example of FIG. 12, processing for filling a gap from the image as in the example of FIG. 6 is performed. The process for filling the gap may be performed using a known method.

  Here, when the distance between adjacent nodes and / or links shown in white is narrow as in the example of FIG. 6, the generated image can be reached within a predetermined time as in the example of FIG. 12. Range is extracted as one region. On the other hand, when the interval between adjacent nodes and / or links shown in white is wide, the generated image does not look like the example of FIG. 12, for example, there are two or more reachable ranges within a predetermined time. It is extracted as a region. In this case, based on the road density described above, a process of changing the size (thickness) of filling in white the positions indicating nodes and / or links that can be reached within a predetermined time may be used. Further, the expansion or contraction of the area displayed in white may be repeated depending on the road density. For example, when the road density is sparse, the distance between adjacent white pixels is increased. Thereby, a reachable range within a predetermined time is extracted as one region. Further, based on the distance from the departure point to a node and / or link that can be reached within a predetermined time, the region at the position displayed in white may be repeatedly expanded or contracted. Further, based on the screen size (resolution), the region at the position displayed in white may be repeatedly expanded or contracted. Further, in consideration of the water system and the land system of the map image, the expansion or contraction of the area displayed in white may be repeated. For example, it cannot be expanded in the direction of the water system, and can be expanded in the direction of the land system. Thereby, a reachable range within a predetermined time is extracted as one region.

  Next, in step S52, a process of smoothing the white and black boundary lines in the image generated in step S51 is performed. Specifically, as in the example of FIG. 13, processing for smoothing the white and black boundary lines from the image as in the example of FIG. 12 is performed. Thereby, as in the example of FIG. 13, the visibility of an image obtained by superimposing a finally reachable range on the map image can be improved by smoothly processing the white and black boundary lines. The smoothing process may be performed using a known method.

  In subsequent step S53, a contour curve that is a boundary between white and black is extracted from the image generated in step S52. Specifically, as in the example of FIG. 14, processing is performed to extract a contour curve 302 that is a boundary between white and black from the image as in the example of FIG. 13. The process for extracting the contour curve may be performed using a known method. FIG. 15 is a display example of a contour curve indicating the reachable range. In addition, a contour curve coordinate sequence is extracted in a direction that goes around clockwise around an arbitrary point as a starting point. Further, the extracted contour curve coordinate sequence is stored from “start X coordinate, start Y coordinate” to “end X coordinate, end Y coordinate” as in the example of FIG. Note that the extracted contour curve coordinate sequence is stored in the working area unit 17.

  Next, in step 5 of FIG. 3, the image superimposing unit 114 superimposes the contour curve 302 obtained in step S <b> 53 on the map image 300. FIG. 16 is a display example displayed on the display device 151 by superimposing a contour curve indicating a reachable range on the map image.

  Next, referring to FIG. 17 and FIG. 18, the image processing unit 113 uses the dynamic contour model to perform another image generation processing operation for obtaining a contour curve indicating a reachable range within a predetermined time. explain. FIG. 17 is a flowchart showing the operation of another image extraction process.

  First, in FIG. 17, steps S61 and S62 process images in the same manner as steps S51 and S52 of FIG.

  In the subsequent step S63, the image processing unit 113 uses a dynamic contour model (M. Kass: “Snakes: Active Control Models”, Informational Journal of Computer vision, 1, 4, pp. 321-331 (1988)). The contour curve indicating the reachable range within a predetermined time is extracted. Here, in the active contour model, first, a curve in an initial state is set, and the curve is sequentially deformed so as to minimize energy. Thereby, the curve in the final state is extracted as an outline indicating the reachable range. The energy can be defined as a function for smoothly drawing to the edge. Further, as the sequential correction method, for example, a variational method, a Greedy Algorithm, or a dynamic programming method may be used.

  Next, with reference to FIG. 18, the sequential deformation of a curve when extracting a contour when using the active contour model in step 63 will be described. FIG. 18 is a schematic diagram illustrating an example of a state in which the curve when the active contour model is applied in step 63 in FIG. 17 is sequentially deformed from the initial state to the final state.

  In FIG. 18, a curve 400 indicates an initial state, a curve 401 indicates an intermediate state, and a curve 402 indicates a final state. The curve 400 in the initial state may have any shape as long as it is a closed curve larger than the region indicated in white where the position indicating the node and / or the link that can be reached within a predetermined time is shown. For example, in the case of automatic setting, a circular shape set as a search range by the search unit 111 may be a curve in an initial state. Specifically, if the search range is a circle with a radius of 5000 m centering on the starting point, the circular shape is converted into an image processing coordinate system and arranged. As for the curve 402 in the final state, a contour curve coordinate sequence is extracted and stored in the working area unit 17 as in the example of FIG. As a result, the image superimposing unit 114 superimposes the contour curve obtained using the active contour model on the map image and displays the contour curve on the display device 151.

  As described above, according to the reachable range display device according to the present embodiment, all intersections that can be reached within a predetermined time from the current position of the vehicle without setting the number of divisions in advance by the user. By displaying the image indicating the link connecting the node indicating the node and / or the node indicating the intersection on the map image, it is possible to indicate a reachable range with high reliability and visibility. As a result, it is possible for the user to grasp at a glance how far and how long it can be reached.

(Second Embodiment)
Next, the reachable range display device according to the second embodiment will be described. In the second embodiment as well, as in the first embodiment, an example in which the present invention is applied to a navigation device that guides a vehicle to a destination will be described as an example of a reachable range display device. Moreover, since the structure of the reachable range display apparatus in 2nd Embodiment is the same structure as the navigation apparatus 1 in 1st Embodiment, detailed description is abbreviate | omitted. In the second embodiment, a search method and a display screen when performing a search process of a reachable range within a predetermined time in the reachable range display device will be mainly described.

  First, when a node and / or a link that can be reached within a predetermined time is searched by the search unit 111, the same processing as in the first embodiment, that is, steps S51 and S52 of FIGS. 5 and 11 are executed. The As a result, an image (hereinafter referred to as an in-time image) as in the example of FIG. 13 is generated.

  On the other hand, when the search unit 111 searches for a node and / or a link that can be reached over a predetermined time, the processes of steps S31 and S32 in FIG. 19 are executed. Thereby, an image like the example of FIG. 20 is produced | generated. FIG. 20 is a display example of an image in which a predetermined size is filled with black, and a position indicating a reachable node in the search range is filled with white over a predetermined time. Here, since the search unit 111 sets a search range condition in advance for a search for reachable nodes in the search range over a predetermined time, as shown in the example of FIG. The search is limited in all directions.

  Next, the operation of the image extraction process in FIG. 20 will be described with reference to FIG. FIG. 21 is a flowchart showing the operation of the image extraction process.

  First, in FIG. 21, in the image generated as in the example of FIG. 20, the position indicating the node and / or the link that can be reached over a predetermined time is displayed in black inside the portion displayed in white. The process which fills the clearance gap which is a part to be performed is performed (step S81). However, in FIG. 20, nodes and / or links that can be reached within a predetermined time, that is, regions displayed in black are not gaps. Specifically, as in the example of FIG. 22, processing for filling a gap from the image as in the example of FIG. Note that the process of filling the gap is the same as the method described above.

  Next, in step S82, a process for smoothing the white and black boundary lines in the image generated in step S81 is performed. Specifically, as in the example of FIG. 23, processing for smoothing the white and black boundary lines from the image as in the example of FIG. 22 is performed. The smoothing process is the same as that described above.

  Next, in step S83, the image generation unit 112 generates an image obtained by reversing black and white (hereinafter referred to as an overtime image) among the images generated in step S82. Specifically, as in the example of FIG. 24, white and black are reversed from the image as in the example of FIG.

  Subsequently, the logical product of the two images obtained by executing the processes of FIG. 11 and FIG. 21 is taken, and an overlapping region of the white region of the in-time image and the white region of the non-time image is extracted. Specifically, a region where the region shown in white in FIG. 13 and the region shown in white in FIG. 24 overlap is extracted. As a result, the image generation unit 112 generates an image like the example of FIG.

  Next, a logical product of the overlap area of the white area of the in-time image and the white area of the out-of-time image is obtained, and the contour curve that becomes the boundary between white and black in the generated image as in the example of FIG. To extract. Specifically, as in the example of FIG. 26, processing is performed to extract a contour curve 502 that is a boundary between white and black from the image as in the example of FIG. The process for extracting the contour curve is the same as that described above. In addition, the coordinate sequence of the contour curve 502 is extracted in a direction that goes around clockwise around an arbitrary location as a starting point. Further, the extracted contour curve coordinate sequence is stored in the working area unit 17.

  Next, the image superimposing unit 114 superimposes the contour curve 502 obtained above on the map image 500. FIG. 27 is a display example in which a contour curve 502 indicating a reachable range is displayed on the display device 151 while being superimposed on the map image 500. Further, when the contour curve 302 showing the reachable range shown in FIG. 16 and the contour curve 502 showing the reachable range shown in FIG. 27 are contrasted, the contour curve 502 is slightly narrower than the contour curve 302. In other words, in the contour curve 502 indicating the reachable range, nodes that can be reached beyond the predetermined time existing inside the contour curve 302 indicating the reachable range are excluded. As a result, a more reliable reachable range display can be performed.

  As described above, according to the reachable range display device according to the present embodiment, all intersections that can be reached within a predetermined time from the current position of the vehicle without setting the number of divisions in advance by the user. By displaying the image indicating the link connecting the node indicating the node and / or the node indicating the intersection on the map image, it is possible to indicate a reachable range with high reliability and visibility. As a result, it is possible for the user to grasp at a glance how far and how long it can be reached.

  In the first embodiment and the second embodiment, the contour curve indicating the range that can be reached within a predetermined time is superimposed on the map image. However, the present invention is not limited to this, and FIG. Alternatively, an area in which positions indicating nodes and / or links reachable within a predetermined time in FIG. 7 are displayed in white may be superimposed on the map image. Moreover, you may use arbitrary colors for the color of the area | region or part displayed in white. Further, a transmission process may be performed.

  In the first embodiment and the second embodiment, the image generation unit 112 divides the map image into a land system and a water system, generates an image in which the land system is white and the water system is black. The contour curve indicating the reachable range may be obtained by calculating a logical product from the images of FIGS. FIG. 28A is the same as the image shown in FIG. 13 or FIG. 27 in the first embodiment and the second embodiment. FIG. 28B is a diagram showing a state where the land system is white and the water system is black. For example, the logical product is obtained from FIG. 28A and FIG. 28B in the same manner as in the first and second embodiments. As a result, the image generation unit 112 generates an image like the example of FIG. 28C. Further, a contour curve is obtained from the image of FIG. 28C in the same manner as in the first embodiment and the second embodiment. As a result, the contour curve indicating the reachable range is always drawn in the land system range, and the reachable range display with high reliability can be performed.

  As mentioned above, although this invention was demonstrated in detail, the said description is an illustration in all the meanings, and is not restrictive. Of course, many other modifications and variations are possible without departing from the scope of the invention.

  A reachable range display device, a reachable range display method, and a program thereof according to the present invention include a map display application that operates on a navigation device or a personal computer, a mobile phone, a taxi, a vehicle allocation / command system in a security company, etc. Can be applied to any device or system capable of displaying

Function showing the configuration of the navigation device according to the first embodiment The figure which shows an example of node data among the map information stored in the map information storage part 12 which concerns on 1st Embodiment. The figure which shows an example of link data among the map information stored in the map information storage part 12 which concerns on 1st Embodiment. The figure which shows an example of a road classification among the map information stored in the map information storage part 12 which concerns on 1st Embodiment. The flowchart which shows the flow of a process of the control part 11 whole. Flow chart showing operation of route search processing The flowchart showing the operation | movement of the image generation process in the 1st Embodiment of this invention. The figure which shows the state which filled the position which shows the node which can be reached within the predetermined time with the black with the predetermined size filled with the white The figure which shows the state which filled the position which shows the node and the link which can be reached within the predetermined time with the black and the predetermined size is filled with the white A diagram for explaining the position to fill in the vicinity of a node that can be reached within a predetermined time Flow chart showing operation of other image generation processing Schematic diagram showing an example of a method of dividing a map image concentrically. The flowchart showing the operation | movement of the image extraction process in the 1st Embodiment of this invention. The figure which shows a mode that FIG. 6 was processed to fill the gap The figure which shows a mode that the process which smoothes the boundary of white and black of FIG. The figure which shows a mode that the outline curve used as the boundary of white and black of FIG. 13 was extracted Schematic diagram showing an example of the storage format of the contour curve coordinate sequence Display example in which a contour curve indicating a reachable range in the first embodiment of the present invention is superimposed on a map image and displayed on the display device 151 Flow chart showing operation of other image extraction processing Schematic diagram showing an example of how the curve is sequentially deformed from the initial state to the final state when the active contour model is applied The flowchart showing the operation | movement of the image generation process in the 2nd Embodiment of this invention. The figure which shows the state which filled the position which shows the node which can be reached over a predetermined time by filling a predetermined size in black and white The flowchart showing the operation | movement of the image extraction process in the 2nd Embodiment of this invention. The figure which shows a mode that FIG. 21 was processed to fill the gap. The figure which shows a mode that the process which smoothes the boundary of white and black of FIG. The figure which shows a mode that the process which reversed white and black of FIG. 22 was performed The figure which shows a mode that carried out the theoretical product from the image of FIG. 13 and FIG. The figure which shows a mode that the outline curve used as the boundary of white and black of FIG. 25 was extracted Display example in which a contour curve indicating a reachable range in the second embodiment of the present invention is superimposed on a map image and displayed on the display device 151 The figure which shows a mode that the process which smoothes the boundary of white and black of FIG. A diagram showing the land system white and the water system black The figure which shows a mode that carried out the theoretical product from the image of FIG. 28A and FIG. 28B

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 11 Control part 12 Map information storage part 13 Positioning part 14 Input part 15 Output part 16 Traffic information receiving part 17 Working area part 111 Search part 112 Image generation part 113 Image processing part 114 Image superimposition part 151 Display apparatus 300,500 Map image 302, 502 Contour curve 400 Curve indicating initial state 401 Curve indicating intermediate state 402 Curve indicating final state

Claims (16)

A reachable range display device that displays a reachable range within a predetermined time from a reference point on a map on a map image,
A search unit that searches for an optimum route from the reference point to any of a plurality of points on any of the map images and calculates a required time;
An image generation unit that generates a first image that can be distinguished from a point group that can be reached within a predetermined time searched by the search unit;
An image processing unit that generates a second image indicating a reachable range from the reference point within a predetermined time from the first image generated by the image generation unit;
An reachable range display device comprising: an image superimposing unit that superimposes the second image generated by the image processing unit on the map image and displays the image on a display screen. The image generation unit generates a first image in which a point group reachable within a predetermined time searched by the search unit from the reference point is indicated by a predetermined color,
The reachable range display according to claim 1, wherein the image processing unit generates a second image indicating a reachable range from the reference point within a predetermined time from the first image indicated by the predetermined color. apparatus.   The image generation unit generates a first image in which pixels indicating points that are reachable within a predetermined time searched for by the search unit from the reference point are fattened around the respective pixels with the predetermined color. The reachable range display device according to claim 2.   The image generation unit reaches from the reference point within a predetermined time searched by the search unit from the reference point among pixels indicating the point group that can be reached within the predetermined time searched by the search unit from the reference point A first image in which pixels at a boundary with an impossible point group are thickened with the predetermined color only on the reference point side, and pixels other than the boundary are thickened with pixels of the predetermined color around each of the pixels. The reachable range display device according to claim 2, which is generated.   The said image generation part produces | generates the 1st image shown by a predetermined color using the path | route from the said reference point to each of the point group which can be reached within the predetermined time searched by the said search part. The reachable range display device described in 1.   The reachable range display device according to claim 5, wherein the image generation unit determines a thickness for filling the route with a predetermined color based on a road type of the route. The image generation unit fills an area on the map including all the reachable point groups in the first color with the first color, and sets the unreachable point groups different from the first color. An outline extraction unit that generates an image filled with two colors and extracts an outline curve that is a boundary between the first color and the second color;
The reachable range display device according to claim 1, wherein the image superimposing unit superimposes the contour curve on the map image and displays the contour curve on a display screen.   The reachable range display device according to claim 7, wherein the contour extraction unit extracts a boundary between the first color and the second color by setting the first color to black and the second color to white. .   The reachable range display device according to claim 7, wherein the contour extraction unit extracts the contour curve using a predetermined dynamic contour model. The search unit searches for an optimum route from the reference point to any of a plurality of points existing in the search range, using a circular area centered on the reference point and having a radius of a predetermined distance as a search range. To calculate the required time
The reachable range display device according to claim 9, wherein the contour extraction unit uses the circular region used by the search unit as a curve in an initial state when the dynamic contour model is used. The search unit calculates a road density based on the number of routes from the reference point existing in a predetermined range centered on the reference point to any of a plurality of points on any of the map images. Further comprising
The image generation unit, based on the road density calculation result calculated by the road density calculation unit, the number of pixels to fatten the pixels indicating the reachable point group around each of the pixels of the predetermined color The reachable range display device according to claim 3, wherein the reachable range display device is determined based on a road density.   The road density calculation unit divides a predetermined range centered on the reference point into concentric or mesh regions, and calculates the road density based on the number of the routes existing in each of the divided regions. The reachable range display device according to claim 11, wherein the reachable range display device calculates.   The image generation unit generates an image indicating the reachable point group and an image indicating the unreachable point group, performs a predetermined calculation on a region where the image overlaps, The reachable range display device according to claim 1, further comprising a logical operation unit that generates a first image that can be distinguished from an unreachable point group.   The logical operation unit generates an image in which the unreachable point group is filled with a first color and the reachable point group is filled with a second color different from the first color, and the reachable An unreachable point group is filled with the second color to generate an image in which the reachable point group is filled with the first color, and the reachable point group is obtained using a logical product of the two images. The reachable range display device according to claim 13, wherein a first image that can be distinguished from the unreachable point group is generated. A reachable range display method for displaying a reachable range on a map image within a predetermined time from a reference point on a map,
A search step of searching for an optimal route from the reference point to any of a plurality of points on any of the map images and calculating a required time;
An image generation step of generating a first image capable of distinguishing between a point group reachable within a predetermined time searched by the search step and a point group unreachable;
An image processing step of generating a second image indicating a range reachable within a predetermined time from the reference point from the first image generated by the image generation step;
A reachable range display method comprising: an image superimposing step of superimposing the second image generated in the image processing step on the map image and displaying the second image on a display screen. A reachable range display program executed by a computer of a reachable range display device that displays a reachable range on a map image within a predetermined time from a reference point on a map,
In the computer,
A search step of searching for an optimal route from the reference point to any of a plurality of points on any of the map images and calculating a required time;
An image generation step of generating a first image capable of distinguishing between a point group reachable within a predetermined time searched by the search step and a point group unreachable;
An image processing step of generating a second image indicating a range reachable within a predetermined time from the reference point from the first image generated by the image generation step;
An reachable range display program for executing an image superimposing step of superimposing the second image generated in the image processing step on the map image and displaying the second image on a display screen.

Images