JP2006250662A - Navigation system and method of searching guidance route - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system and a method of searching guidance route capable of properly setting the route without getting down to a ramp way vainly, or setting a route without going a long way around the ramp way corresponding to the destination. <P>SOLUTION: Regarding with a connecting relation to a node between an approaching link and leaving link, traffic regulation information is defined. To both the approaching link and leaving link, concerning the connection relation between ramp ways c and a, the traffic regulation information that the travelling is capable but not recommended is defined, thereby not only uniquely weighting the ramp way but also only weighting the route that enters the ramp way from the main line and again returns to the main line, while for the route that enters the other road from the main line via the ramp way, or enters the main line from the other road via the ramp way, the weighting to the link cost does't performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a navigation device and a guidance route search method.

  In general, in-vehicle navigation devices detect the current position of a vehicle using a self-contained navigation sensor, a GPS (Global Positioning System) receiver, or the like, read out map data in the vicinity of the vehicle, and display it on a screen. Then, the vehicle position mark indicating the vehicle position is superimposed and displayed at a predetermined location on the screen, so that it can be seen at a glance where the vehicle is currently traveling.

  Also, most recent navigation devices are equipped with a route guidance function. This route guidance function automatically searches for the route with the lowest cost from the current location to the destination using map data, and uses the searched route as a guidance route to change the color of other roads on the map screen. draw. Further, when the vehicle approaches a guidance intersection on the guidance route within a certain distance, an enlarged view of the intersection is displayed and the intersection is guided to guide the driver to the destination.

  Cost is a value obtained by multiplying a predetermined constant according to the road width, road type, right and left turns, traffic regulations, etc., based on the distance. is there. In the route search process, the link costs on various routes from the current location to the destination are sequentially added, using the points connecting multiple roads such as intersections and branches as nodes and the vectors connecting adjacent nodes as links. The route with the smallest sum is selected.

  Incidentally, the links and nodes at the elevated intersection are set as shown in FIG. In FIG. 7, 101 is a link that represents the main road of the elevated road, 102 and 103 are links that represent a three-dimensional intersection with the main road of the elevated road, and 104 is a ramp road for entering the intersection from the main road of the elevated road. A link 105 represents a ramp road for entering the main line of the elevated road from the intersection. 201 is a node where the main road link 101 of the elevated road intersects with the ramp road link 104 to the intersection, 202 is a node where the intersection road links 102 and 103 and the ramp road links 104 and 105 intersect, and 203 is the main line of the elevated road. The link 101 and the ramp road link 105 from the intersection to the main line intersect.

  The ramp road is usually used when entering the intersection from the main line or entering the main line from the intersection. However, if links and nodes at elevated intersections are set in this way, depending on the road conditions, a route that exits the main road of the elevated road, runs on the ramp road, and returns to the main road of the elevated road is selected as the guide route. Sometimes. For example, when the width of the main line is narrower than the width of the ramp road as shown in FIG. 8 (a), when the distance of the main line is longer than the distance of the ramp road as shown in FIG. 8 (b), Thus, when there is traffic congestion on the main line, a useless route that gets off the main line, runs on the ramp road, and returns to the main line may be selected.

Conventionally, in order to avoid such an inconvenience, a constant coefficient (for example, a weighting factor of 2 to 3 times the normal weight) is given to the ramp road links 104 and 105 when searching for a guidance route, thereby increasing the link cost. Thus, a technique has been proposed in which the ramp road links 104 and 105 are less likely to be selected as a guide route (see, for example, Patent Documents 1 and 2).
JP-A-11-201768 JP 2000-292188 A

  However, as in Patent Documents 1 and 2, even if it is better to pass the ramp road by simply weighting the link costs of the ramp road links 104 and 105 uniquely, it does not pass the ramp road. There was a problem that a detour route might be selected. For example, as shown in FIG. 9, depending on the location of the destination 300, it is originally better to pass the ramp road like an ideal route 301 indicated by a dotted line, but the ramp road passes by the weighting of the link cost. Due to the difficulty, a bypass route 302 as indicated by a solid line may be selected.

  In the techniques described in Patent Documents 1 and 2, when searching for a guide route, as software processing of the guide route search application program, it is determined whether the road is a ramp road or the road type is changed. It is necessary to determine whether or not. Since such determination processing must be performed at the time of route search, there is also a problem that the route search time is increased accordingly.

The present invention has been made to solve such a problem, and a route that does not pass through the ramp road (route that passes through the main line without getting down on the ramp road) or a route that passes through the ramp road is used as the destination. The purpose is to enable appropriate setting.
Another object of the present invention is to enable searching for such an appropriate route in a shorter time.

  In order to solve the above-described problem, according to the present invention, the traffic regulation information defined for the nodes existing in the map data is set according to the inter-link connection relation of a plurality of links connected to one node. It is trying to define. That is, the traffic regulation information is defined according to the connection relationship between the incoming link for one node and the outgoing link from one node. For example, the traffic regulation information that both the entrance link and the exit link are allowed to pass but is not recommended for the link connection relationship of the ramp road.

  In another aspect of the present invention, two links having the same node at both ends with respect to a road in a predetermined section are defined on the map data, and the two links are connected at the node to which the two links are connected. Each traffic regulation for links is defined. For example, a road in a predetermined section is a ramp road to the main line, and traffic restriction information that prohibits passage between two links corresponding to the ramp road is defined, and the node where the ramp road and the main line are connected The traffic restriction information that is impassable for one of the two links is defined.

  According to the present invention configured as described above, the link cost is not weighted uniformly on the ramp road, but the link cost is weighted only on the route that enters the ramp road from the main line and returns to the main road. Become. On the other hand, the link cost is not weighted for a route that passes the ramp road from the main line and enters another road, or a route that passes the ramp road from another road and enters the main line. As a result, it is possible to appropriately set the guide route that passes only the main line without getting down to the ramp road, or the guide path that passes through the ramp road without wastefully detouring toward the main line according to the destination. Become.

  Further, according to the present invention, the link cost may be simply weighted according to the traffic regulation information defined in advance on the map data. In other words, in order to weight the link cost, it is necessary to perform software processing such as determining whether the link of the search branch is a ramp road or determining whether the road type has changed. Absent. Therefore, it is possible to search for an appropriate guide route that passes or does not pass through the ramp road according to the destination in a shorter time.

(First embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a navigation device according to the first embodiment.

  In FIG. 1, reference numeral 1 denotes a map recording medium such as a DVD-ROM, which stores map data necessary for map display, route search, and the like. Here, the DVD-ROM 1 is used as a recording medium for storing the map data, but other recording media such as a CD-ROM and a hard disk may be used. Reference numeral 2 denotes a DVD-ROM control unit which controls reading of data from the DVD-ROM 1.

  The map data stored in the DVD-ROM 1 includes a drawing unit composed of various data necessary for map display and a road unit composed of data necessary for various processes such as map matching and route search. Yes. A road unit corresponds to a road, a lane, or the like that connects information about a node corresponding to a point where a plurality of roads intersect, such as an intersection or a branch, and a node on the road and another adjacent node. Information about the link. That is, the road unit includes a connection node table storing detailed data of all nodes and a link table storing detailed data of links specified by two adjacent nodes.

  The connection node table includes information such as normalized longitude / latitude of nodes, attribute flags, the number of traffic regulations, and traffic regulation records for each existing node. The normalized longitude / latitude indicates a relative position in the longitude direction / latitude direction with respect to the section. The attribute flag includes an intersection node flag indicating whether or not the node is an intersection node. The number of traffic regulations indicates the number of traffic regulations when there is traffic regulation such as right turn prohibition or U-turn prohibition on the link connected to the node. The traffic regulation record indicates the specific contents of the traffic regulation corresponding to the number of traffic regulations described above, if any.

  In the present embodiment, the traffic regulation information stored in the traffic regulation record is defined according to the inter-link connection relationship of a plurality of links connected to one node. Specifically, it is defined according to the connection relationship between the incoming link for one node and the outgoing link from one node. Here, the node defining the traffic regulation information corresponding to the connection relationship between the entry link and the exit link is a node where at least one of the entry link and the exit link is a ramp road. More specifically, it may be only a node to which two or more ramp road links are connected. For nodes to which no ramp road link is connected, traffic restriction information similar to the conventional one, that is, simple traffic restriction information that does not depend on the connection relationship between the entry link and the exit link may be defined.

  FIG. 2 is a diagram illustrating an example of traffic regulation information according to the first embodiment defined in accordance with the connection relationship between the entrance link and the exit link. Here, FIG. 2A is a diagram showing the situation of the node N that defines such traffic regulation information and the links a to d connected thereto, and FIG. 2B shows an example of specific traffic regulation information. FIG.

  In FIG. 2 (a), links a and c are ramp road links, and links b and d are cross road links that three-dimensionally intersect the main line running parallel to the ramp road. The node N is a node to which two ramp road links a and c are connected, and is a target node for defining traffic restriction information according to the connection relationship between the entrance link and the exit link. The links x, y, and z are main road links of an elevated road that runs parallel to the ramp road.

  In FIG. 2 (b), when the approach link is the ramp road link c and the exit link is the ramp road link a, that is, with respect to the link connection relationship in which both the entrance link and the exit link are the ramp road, But is not recommended ”. Further, when the approach link is the ramp road link c and the exit link is the intersection road links b and d, or when the entrance link is the intersection road links b and d and the exit link is the ramp road link a, that is, the entrance link. For the link connection relationship in which only one of the exit link and the exit link is a ramp road, the traffic regulation information “permitted” is defined.

  Since the ramp road link c is one-way toward the node N, the traffic regulation information “U-turn prohibited” is defined for the interlink connection relationship of the ramp road link c for both the entrance link and the exit link. Is done. Further, although not shown in FIG. 2B, the traffic regulation information “prohibition of traffic” is defined for all the links whose escape links are ramp road links c. Since the other ramp road link a is one-way in the direction away from the node N, the traffic regulation information of “no traffic” is defined for all the incoming links that become the ramp road link a.

  The link table in the road layer includes information such as link distance, link cost, road attribute flag, road type flag, and the like. The link distance indicates the actual distance of the actual road corresponding to the link. The cost of the link is, for example, the time required for traveling the link is calculated from the road type or the like, and the time required for passing the link is shown in minutes, for example. Moreover, the coefficient which represented the time required for the passage of the link with the relative ratio between each link may be sufficient. The road attribute flag indicates various attributes relating to the link. The road type flag indicates a type indicating whether the actual road corresponding to the link is an expressway or a general road.

  Returning to FIG. 1, reference numeral 3 denotes a position measuring device for measuring the current position of the vehicle, which includes a self-contained navigation sensor, a GPS receiver, a position calculating CPU, and the like. The self-contained navigation sensor includes a vehicle speed sensor (distance sensor) that outputs a single pulse for each predetermined travel distance to detect the travel distance of the vehicle, and an angular velocity sensor such as a vibration gyro that detects the rotation angle (movement direction) of the vehicle. (Relative orientation sensor). The self-contained navigation sensor detects the relative position and direction of the vehicle using these vehicle speed sensor and angular velocity sensor.

  The position calculation CPU calculates the absolute own vehicle position (estimated vehicle position) and vehicle direction based on the relative position and direction data of the own vehicle output from the self-contained navigation sensor. The GPS receiver receives radio waves transmitted from a plurality of GPS satellites by a GPS antenna and performs a three-dimensional positioning process or a two-dimensional positioning process to calculate the absolute position and direction of the vehicle (the vehicle direction is The calculation is based on the current vehicle position and the current vehicle position one sampling time ΔT before).

  A map information memory 4 temporarily stores map data read from the DVD-ROM 1 under the control of the DVD-ROM control unit 2. In other words, the DVD-ROM control unit 2 inputs information on the current vehicle position from the position measuring device 3 and outputs an instruction to read out map data in a predetermined range including the current vehicle position, thereby displaying a map display and a guidance route. The map data necessary for the search is read from the DVD-ROM 1 and stored in the map information memory 4. The map information memory 4 corresponds to the map data storage unit of the present invention.

  Reference numeral 5 denotes an operation unit such as a remote controller. The user sets various information (for example, a route guidance destination and waypoint) for the navigation device, and various operations (for example, menu selection operation, enlargement / reduction). Various controls (buttons, joysticks, etc.) for performing operations, manual map scrolling, numerical input, etc. are provided. Reference numeral 6 denotes a remote control interface which receives an infrared signal corresponding to the operation state from the remote control 5.

  Reference numeral 7 denotes a processor (CPU) which controls the entire navigation device. A ROM 8 stores various programs (such as a guidance route search program). Reference numeral 9 denotes a RAM which temporarily stores data obtained during various processes and data obtained as a result of various processes.

  The above-described CPU 7 performs a process of searching for a guide route with the lowest cost connecting the current location to the destination using the map data stored in the map information memory 4 in accordance with the guide route search program stored in the ROM 8. . That is, link costs set on various routes from the current location to the destination are sequentially added, and a route having the smallest link cost is selected as a guide route. Thus, CPU7 comprises the route search means of this invention.

  A guidance route memory 10 stores guidance route data searched by the CPU 7. The guidance route data stores the position of each node and an intersection identification flag indicating whether each node is an intersection, corresponding to each node from the current location to the destination.

  When the CPU 7 searches for a guidance route, an intersection network list of a predetermined range including the current location and the destination is created in advance and stored in a work memory such as the RAM 9. The intersection network list is obtained by extracting intersections from all the nodes included in the road unit and collecting data necessary for route search processing for each intersection. The intersection network list includes information prepared in advance before the route search is executed and information registered when the route search is executed. The latter information includes the sequential number of the previous intersection determined when the search branches are sequentially extended during the route search, and the total cost from the current location to the intersection.

  The specific processing procedure when searching for a guidance route is as follows. First, when a route search destination is set by operating the remote controller 5, the CPU 7 stores the destination data in the guidance route memory 10. When a route search instruction is issued by operating the remote controller 5, the vehicle position at that time is set as departure point data and stored in the guidance route memory 10. Then, a travel route connecting the starting point and the destination stored in the guide route memory 10 is searched under the conditions specified by the user. For example, the guide route that minimizes the cost under any of the conditions such as the shortest time, the shortest distance, and the shortest charge is searched and set.

  When calculating the cost, the CPU 7 weights the link cost of the exit link according to the contents of the traffic regulation information shown in FIG. That is, after the link cost of the target link is multiplied by a constant (a fixed value may be added), a route search is performed using the link cost weighted in this way. Here, an extremely large weight is applied to the exit link in which the traffic regulation information such as “U-turn prohibition” and “traffic prohibition” is defined. No weight is applied to the exit link in which the “traffic permitted” traffic restriction information is defined (the link cost is originally set as it is). In addition, a relatively large weight is applied to the exit link in which the traffic restriction information of “Allowable but not recommended” is defined.

  For example, in the example of FIG. 2, when a route from the ramp road link c to the ramp road link a is used as a search branch, a relatively large weight is applied to the link cost of the ramp road link a serving as an exit link. Accordingly, it is difficult to select a route from the main link x through the ramp road links c and a to the main link z. Instead, the total link cost of the route that passes through the main links x, y, and z as they are becomes smaller, and the main links x, y, and z are selected as part of the guide route.

  On the other hand, when the route from the ramp road link c to the intersection road links b and d is used as a search branch, no weight is applied to the link cost of the ramp road links b and d serving as exit links. It is possible to select a route. That is, depending on the location of the destination, the route from the ramp road link c to the intersection road links b and d is selected as a part of the guide route.

  Reference numeral 11 denotes a display controller that generates map image data necessary for display on the display device 17 based on the map data stored in the map information memory 4. A video RAM 12 temporarily stores image data generated by the display controller 11. That is, the image data generated by the display controller 11 is temporarily stored in the video RAM 12, and image data for one screen is read and output to the image composition unit 16.

  A menu generation unit 13 generates and outputs a menu image necessary when various operations are performed using the remote controller 5. Reference numeral 14 denotes a guidance route generator, which generates guidance route drawing data using the result of route search processing stored in the guidance route memory 10. That is, from the guidance route data stored in the guidance route memory 10, the one included in the map area drawn in the video RAM 12 at that time is selectively read out, and the predetermined color different from other roads is superimposed on the map image Draws the guidance path highlighted in bold.

  A mark generating unit 15 generates and outputs a vehicle position mark displayed at the vehicle position after the map matching process, various landmarks displaying a gas station, a convenience store, and the like. Note that the map matching process includes the map data read into the map information memory 4, the vehicle position and vehicle orientation data measured by the GPS receiver measured by the position measuring device 3, and the estimated vehicle by the autonomous navigation sensor. This refers to processing for correcting the position of the vehicle on the road of the map data using the position and vehicle direction data.

  Reference numeral 16 denotes an image synthesis unit that synthesizes and outputs various images. That is, the map image data read by the display controller 11 is superimposed on the image data output from each of the menu generation unit 13, the guidance route generation unit 14, and the mark generation unit 15 to perform image synthesis. The processed image data is output to the display device 17. Thereby, the map information around the host vehicle is displayed on the screen of the display device 17 together with the vehicle position mark and various landmarks. If a guidance route is set, the guidance route is displayed on this map.

  Reference numeral 18 denotes a voice generation unit that utters voice for guiding the traveling direction of the host vehicle, voice for various operation guidance, and the like. Reference numeral 19 denotes a speaker, which outputs the sound generated by the sound generator 18 to the outside.

  Next, a guidance route search method performed by the navigation device according to the first embodiment configured as described above will be described. FIG. 3 is a flowchart showing the operation of the guidance route search process according to the first embodiment. In FIG. 3, first, the DCD-ROM control unit 2 reads map data including the vicinity of the current position from the DVD-ROM 1 and stores it in the map information memory 4, and stores an intersection network list of a predetermined range including the current position and the destination in the RAM 9 Created above (step S1).

  Next, the CPU 7 extends the search branch from one node (first node at the current location) to the next one (step S2). Then, with reference to the traffic restriction information as shown in FIG. 2B with the previous search branch existing before the node as the incoming link and the newly extended search branch as the outgoing link, other than “passable” It is determined whether or not there is a restriction (step S3). If there is a restriction other than “permitted”, the link cost of the newly extended search branch is weighted according to the restriction contents (step S4). On the other hand, if there is no restriction other than “passable”, the link cost of the newly extended search branch is not weighted.

  After weighting the link cost as necessary in this way, the link cost of the newly extended search branch is further added to the addition result so far, so that the search branch of the newly extended search branch from the current location is added. The total cost to the previous node is obtained (step S5). Then, the CPU 7 determines whether or not a route with the minimum cost has been found as a result of extending the search branch to the destination (step S6). If the route search to the destination has not been completed, Returning to step S2, the process is repeated. On the other hand, when the route search to the destination is finished, the processing of this flowchart is finished. At that time, the route stored in the guide route memory 21 becomes the guide route.

  As described above in detail, according to the first embodiment, the traffic restriction information defined for the nodes existing in the map data is obtained by entering the entry link for one node and the exit link from one node. It is defined according to the connection relationship, and the traffic restriction information “Although it is possible to pass but is not recommended” is defined for the link connection relationship of the ramp road for both the entrance link and the exit link.

  As a result, the link cost of the ramp road is not uniquely increased as in the prior art, and the link cost is increased and regulated only for the route that enters the ramp road from the main line and returns to the main line again. On the other hand, the link cost is not weighted for a route that passes the ramp road from the main line and enters another road, or a route that passes the ramp road from another road and enters the main line. As a result, it is possible to appropriately set a guide route that passes only the main line without getting down on the ramp road, or a guide path that passes through the ramp road without wastefully detouring toward the main line according to the destination.

  4A to 4C are diagrams illustrating examples of guide routes that can be set in the present embodiment. For example, as shown in FIG. 4A, when the destination 300 is ahead of the intersection, it is possible to set a route from the ramp road to the intersection, as shown in FIG. A long circuit route through the main line will not be set. Of course, when the destination 300 is at the end of the main line as shown in FIG. 4B, a route passing through the main line is set as the guide route. In addition, as shown in FIG. 4C, when the current location 400 of the vehicle is on an intersection, it is possible to set a route that passes the ramp road from the intersection and enters the main line as a guide route.

  Further, according to the present embodiment, the link cost may be simply weighted according to the traffic regulation information defined in advance on the map data. In other words, in order to weight the link cost, software processing for determining whether the link of the search branch is a ramp road or determining whether the road type has changed is performed by the search application. There is no need to do it. Therefore, it is possible to search for an appropriate guide route that passes or does not pass through the ramp road according to the destination in a shorter time.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The configuration of the navigation device according to the second embodiment is the same as that shown in FIG. The second embodiment also has a feature in how to hold the map data, and the content is different from that of the first embodiment. FIG. 5 is a diagram illustrating an example of traffic regulation information according to the second embodiment. Here, FIG. 5A is a diagram showing the status of nodes to be defined for traffic regulation information and the status of links connected to them, and FIG. 5B is a diagram showing an example of specific traffic regulation information.

  As shown in FIG. 5A, in the second embodiment, two links having the same node at both ends are defined for the ramp road. That is, in FIG. 5A, links a and c are normal ramp road links, and links a ′ and c ′ are dummy links having the same nodes at both ends as the ramp road links a and c (dummy links are also included). It is a kind of ramp road link, but this name is used to distinguish it from a normal ramp road link). That is, for the ramp road link c having the nodes N1 and N2 at both ends, a dummy link c ′ having the same nodes N1 and N2 at both ends is defined, and the nodes N1 and N3 are at both ends. For the ramp road link a, a dummy link a ′ having the same nodes N1 and N3 at both ends is defined.

  The links b and d are cross road links that are three-dimensionally intersected with the main line running parallel to the ramp road. The nodes N1 to N3 are nodes to which at least one ramp road links a and c are connected, and are nodes for defining traffic restriction information according to the connection relationship between the entrance link and the exit link. The links x, y, and z are main links of the elevated road running parallel to the ramp road.

  As shown in FIG. 5 (b), with respect to the node N1 to which the two ramp road links a and c are connected, there is a mutual connection between the ramp road links a and c and the dummy links a ′ and c ′. Define traffic restriction information of “no traffic” to prevent traffic. That is, for the link connection relationship in which the entry link is the ramp road link c and the exit link is the dummy link a ′, and the link connection relationship in which the entry link is the dummy link c ′ and the exit link is the ramp road link a, ”Is defined.

  On the other hand, for the link connection relationship in which the entry link is the ramp road link c and the exit link is the ramp road link a, and the link connection relationship in which the entry link is the dummy link c ′ and the exit link is the dummy link a ′, ”Is defined.

  Although not shown in FIG. 5 (b), the ingress link is the ramp road link c and the exit link is the cross road link b, d, and the ingress link is exited at the cross road links b, d. For the link connection relation that the link is the ramp road link a or the dummy link a ′, the traffic regulation information “permitted” is defined. Further, the ramp road link c and the dummy link c ′ are one-way traffic from the node N2 toward the node N1. Therefore, the traffic of “no traffic” is used for all the exit links that are the ramp road link c and the dummy link c ′. Regulatory information is defined. Further, the ramp road link a and the dummy link a ′ are one-way traffic from the node N1 toward the node N3. Regulatory information is defined.

  In addition, for the node N2 to which the ramp road link c used when getting off the ramp from the main line is connected, the traffic restriction information of “No traffic” is set so that the main link x cannot enter the dummy link c ′. Define. That is, the traffic regulation information “no traffic” is defined for the inter-link connection relationship where the incoming link is the main link x and the outgoing link is the dummy link c ′. On the other hand, for the link connection relationship in which the entry link is the main link x and the exit link is the ramp road link c, and the link connection relationship in which the entry link is the main link x and the exit link is the main link y, the passage is “permitted” Defines regulatory information.

  Further, regarding the node N3 to which the ramp road link a used for getting on the main road from the ramp road is connected, the traffic restriction of “no traffic” is set so that the ramp road link a cannot enter the main road links y and z. Define information. That is, for the link connection relationship in which the entry link is the ramp road link a and the exit link is the main line link y, and the link connection relationship in which the entry link is the ramp road link a and the exit link is the main line link z, the “traffic prohibited” ”Is defined. On the other hand, for the interlink connection relationship in which the entrance link is the dummy link a ′ and the exit link is the main link z, and the interlink connection relationship in which the entrance link is the main link y and the exit link is the main link z, “passable” is permitted. Defines regulatory information.

  When calculating the cost, the CPU 7 weights the link cost of the exit link according to the contents of the traffic regulation information shown in FIG. That is, after the link cost of the target link is multiplied by a constant (a fixed value may be added), a route search is performed using the link cost weighted in this way. Here, an extremely large weight is applied to the escape link in which the traffic restriction information of “no traffic” is defined. No weight is applied to the exit link in which the “traffic permitted” traffic restriction information is defined (the link cost is originally set as it is).

  When the traffic regulation information is defined as shown in FIG. 5B, for example, a route that enters the ramp road link c from the main line link x and exits to the ramp road link a is set as a search branch (from the ramp road link c to the dummy link a ′ In this case, only the main links y and z are the only search branches ahead, but traffic to the main links y and z is prohibited. As a result, a large weight is applied to the link costs of the main links y and z that are exit links of the ramp road link a. Therefore, it is difficult to select a route that enters the ramp road from the main line and returns to the main line again. Instead, the total link cost of the route that passes through the main links x, y, and z as they are becomes smaller, and the main links x, y, and z are selected as part of the guide route.

  On the other hand, when a route that enters the ramp road link c from the main line link x and exits the intersection road links b and d is used as a search branch, the passage from the ramp road link c to the intersection road links b and d is not prohibited. As a result, no weight is applied to the link costs of the ramp road links b and d, which are exit links of the ramp road link c, and it is possible to select such a route. That is, depending on the location of the destination, the route from the ramp road link c to the intersection road links b and d is selected as a part of the guide route.

  Further, when a route that passes through the dummy link a ′ from the intersection road links b and d and enters the main link z is a search branch (passage from the ramp road link a to the main link z is prohibited, the dummy link a 'Is selected as a search branch), the passage from the intersection links b and d to the dummy link a' and the passage from the dummy link a 'to the main link z are not prohibited. As a result, no weight is applied to the link cost of the dummy link a ′ serving as the exit link of the intersection road links b and d and the main link z serving as the exit link of the dummy link a ′. It is possible to do. That is, depending on the location of the destination, a route that passes through the dummy link a 'from the intersection links b and d and enters the main link z is selected as a part of the guide route.

  From the above, also in the second embodiment, similarly to the first embodiment, various routes as shown in FIGS. 4A to 4C are appropriately set according to the destination. Can do. In the second embodiment, a route as shown in FIGS. 6A to 6C can also be set as a guide route.

  That is, in the second embodiment, the passage itself from the ramp road link c to the ramp road link a is not prohibited, but the passage from the ramp road link a beyond the main road links y and z is prohibited. ing. That is, traffic is prohibited only for a series of paths “main line → ramp road → main line”. Therefore, even when the destination 300 is on the ramp road link a as shown in FIG. 6 (a), the shortest route from the main link x to the ramp road link c to the destination 300 through the ramp road link a. The route can be set appropriately.

  Further, since traffic is prohibited only for a series of paths “main line → ramp road → main line”, even when there are a plurality of intersections on the ramp road as shown in FIG. It is possible to appropriately set the shortest route that passes through to the destination 300. In addition, as shown in FIG. 6C, even when the vehicle deviates from the main line and enters the ramp road, the dummy link c ′, By using the path a ′, the shortest route from the ramp road to the main line and reaching the destination 300 can be appropriately set.

  Also in the second embodiment, similarly to the first embodiment, the link cost may be simply weighted according to the traffic regulation information defined in advance on the map data. In other words, in order to weight the link cost, software processing for determining whether the link of the search branch is a ramp road or determining whether the road type has changed is performed by the search application. There is no need to do it. Therefore, it is possible to search for an appropriate guide route that passes or does not pass through the ramp road according to the destination in a shorter time.

  In the first and second embodiments, the example in which the traffic restriction information related to the ramp road is defined and the guidance route is searched has been described. However, the road on which the traffic restriction information is set is not limited to the ramp road. . For example, when there is a circumstance that traffic is not recommended because a right turn is very crowded at an intersection, road conditions can be controlled by restricting traffic in relation to the entrance link and exit link connected to the node at the intersection. It is also possible to search for a guidance route reflecting the above.

  In addition, a dummy link is set for the route that enters the toll road from the entrance node of one interchange and returns to the ordinary road from the exit node of the next interchange, and for the path “general road → one section of toll road → general road” You may make it regulate traffic. In this way, it is possible to prevent an unrealistic route from being searched for as a guidance route that gets off using only one section of the toll road.

  Further, in the first and second embodiments, the traffic regulation information as shown in FIG. 2B or FIG. 5B is stored on the map data, and the link cost is calculated based on the traffic regulation information. Although weighting is performed, the present invention is not limited to this. For example, information defining the link cost itself in relation to the entry link and the exit link for one node may be stored in the map data, and the defined link cost may be used as it is.

  In addition, each of the above-described embodiments is merely an example of the embodiment for carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

  INDUSTRIAL APPLICABILITY The present invention is useful for a navigation apparatus having a guidance route search function that automatically searches for the route with the lowest cost from the current location to the destination using map data and guides the vehicle to the destination according to the searched guidance route. It is.

It is a block diagram which shows the structural example of the navigation apparatus by 1st and 2nd embodiment. It is a figure which shows the example of the traffic control information which concerns on 1st Embodiment defined according to the connection relation of the approach link and the exit link. It is a flowchart which shows the operation | movement of the guidance route search process by 1st and 2nd embodiment. It is a figure which shows the example of the guidance path | route which can be set in 1st and 2nd embodiment. It is a figure which shows the example of the traffic regulation information which concerns on 2nd Embodiment defined according to the connection relation of the approach link and the exit link. It is a figure which shows the example of the guidance path | route which can be set in 2nd Embodiment. It is a figure which shows the example of a general setting of the link and node in an elevated intersection. It is a figure which shows the example of a setting of the route which passes a ramp way wastefully. It is a figure which shows the example of a useless route setting which goes around without going through a ramp road.

Explanation of symbols

4 Map information memory 7 CPU
10 Guide route memory 14 Guide route generator

Claims (7)

A map data storage unit for storing map data including traffic restriction information for each of the existing nodes, with a node at a point where a plurality of roads intersect, and a road part connecting adjacent nodes as a link;
A route search means for sequentially adding link costs set on various routes from the current location to the destination, and selecting a route having the smallest link cost as a guide route;
The traffic regulation information is defined according to the inter-link connection relation of a plurality of links connected to one node,
The navigation device, wherein the route search means searches for the guidance route using the link cost weighted according to the content of the traffic regulation information. The traffic restriction information according to the link connection relation is defined according to a connection relation between an incoming link to the one node and an outgoing link from the one node. Navigation device. Passage that at least one of the entrance link and the exit link is a ramp road link to the main line, and both the entrance link and the exit link are passable but not recommended for the interlink connection relationship of the ramp road. The navigation apparatus according to claim 2, wherein restriction information is defined. A map data storage unit for storing map data including traffic restriction information for each of the existing nodes, with a node at a point where a plurality of roads intersect, and a road part connecting adjacent nodes as a link;
A route search means for sequentially adding link costs set on various routes from the current location to the destination, and selecting a route having the smallest link cost as a guide route;
On the map data, two links having the same node at both ends are defined for a road of a predetermined section, and the traffic regulation information is the two links at the node to which the two links are connected. Each has its own traffic regulations.
The navigation device, wherein the route search means searches for the guidance route using the link cost weighted according to the content of the traffic regulation information. The road in the predetermined section is a ramp road to the main line, and traffic restriction information that prohibits passage between the two links corresponding to the ramp road is defined, and the ramp road and the main line are connected. 5. The navigation device according to claim 4, wherein, for a node that is present, traffic restriction information that prohibits passage of one of the two links is defined. Map data that includes traffic regulation information for each existing node, with a point where a plurality of roads intersect as a node and a road portion connecting adjacent nodes as a link. A first step of reading out map data in which the traffic restriction information is defined according to the link-to-link connection relationship of
A second step of weighting the link cost as necessary based on the content of the traffic regulation information in the process of extending the search branch link from the current location to the destination;
A third step of sequentially adding the link costs for which the weighting is performed as necessary, and selecting a route having the smallest link cost as a guide route from various routes from the current location to the destination. And a method for searching for a guidance route. Map data that includes traffic regulation information for each existing node, with the point at which multiple roads intersect as a node and the road portion connecting adjacent nodes as a link, and the same node for a given section of road A first step of reading out map data in which two links having both ends are defined, and in the node to which the two links are connected, the traffic restriction information for the two links is defined,
A second step of weighting the link cost as necessary based on the content of the traffic regulation information in the process of extending the search branch link from the current location to the destination;
A third step of sequentially adding the link costs for which the weighting is performed as necessary, and selecting a route having the smallest link cost as a guide route from various routes from the current location to the destination. And a method for searching for a guidance route.

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