JP4501717B2 - Navigation device and program - Google Patents

Description

  The present invention relates to a navigation device and a program for calculating a route with a low total cost as a guide route among routes to a destination and performing route guidance for the calculated guide route.

  Conventionally, various navigation devices for calculating a route with a low total cost as a guide route among routes to a destination and performing route guidance for the calculated guide route have been proposed. Such a navigation apparatus calculates the total cost of a certain route as the sum of the cost of each link in the route. The cost of a link is determined by factors such as the length and width of the link, the road type, and whether or not the link is a link immediately after a right or left turn in the route. For example, the cost of a certain route is higher when there is congestion than when the links in the route are not congested.

  However, the conventional navigation apparatus as described above has the following problems. FIG. 1 shows a schematic view of a road structure including the main highway 41 and the like as viewed from above. This road structure is composed of a highway main line 41 with two lanes on one side, a merge ramp 42 that merges with the highway main line 41 from the right side, and a right side of the highway main line 41 just before the merge ramp 42 merges with the highway main line 41. An exit ramp 43 that branches off, a exit ramp 44 that branches off from the main highway 41 immediately after the junction ramp 42 joins the main highway 41, and a road 45 after the exit ramp 43 and the exit ramp 44 join each other. ,have.

  Here, in such a road structure, the navigation device calculates a guide route for traveling to the facility immediately ahead of the road 45 by traveling to the right in the figure on the left end portion of the highway main line 41 in the figure. think of. In a normal case, in the navigation device, the cost that increases by passing through a branch line such as a ramp is higher than the cost that increases by passing through the main line. A route 46 passing through 41 is calculated as a guide route. Therefore, the route 47 passing through the exit lamp 43 is not easily calculated as a guide route.

  However, after the route 46 has merged with the merge lamp 42, it enters the exit ramp 44 that branches from the same side as the merged side. There is a possibility of crossing with other vehicles entering the main line 41. The shorter the distance between the branch point 49 from the highway main line 41 to the exit ramp 44 and the merge point 50 where the highway main line 41 merges with the merge ramp 42, the shorter the driver is to cross with other vehicles. There is less room to respond and the psychological burden on the driver increases. Therefore, in some situations, it may be more preferable for the driver to reach the destination through the route 47 than to reach the destination through the route 46.

  Even if there is no exit ramp 43, considering the danger of crossing with other vehicles, it is possible to travel on the main highway 41 as the route 48 rather than the route 46. In some cases, it may be preferable for the driver to go past the branch point 49 and get off the main highway 41 from the safer branch point ahead to the destination.

  The present invention calculates a guidance route for a road structure in which there is an exit ramp that branches from the road to the same side as the merge ramp in the vicinity after the merge ramp merges on a road having multiple lanes. The purpose is to take into account the reduction of the driver's burden due to the crossing with other vehicles entering from the junction ramp.

  A first feature of the present invention for achieving the above object is that a navigation device that calculates a route with a low total cost among routes to a destination as a guide route and performs route guidance for the calculated guide route. (1) The route X with respect to the junction of the road Z and the junction ramp in the vicinity of the branch point in the route X including the exit route that exits from the junction of a certain multi-lane road Z to the exit ramp Whether or not (2) the side where the exit ramp of the road Z branches off and the side where the junction ramp joins the road Z are the same side Then, based on the fact that these two determination results are both affirmative, the increase in the cost of the route X due to the existence of the exit route is compared with a case where even one of these two determination results is negative. Big It is to be.

  Such a navigation device has a road structure in which there is an exit ramp that branches from the road to the same side as the merge ramp in the vicinity after the merge ramp merges on a road having a plurality of lanes. Increased value of the total cost value of a route (corresponding to route X) that merges with the merge ramp (corresponding to the road Z) and then exits the exit ramp by exiting the exit ramp For example, (B) exiting to the exit ramp of the total cost value of the route (which also corresponds to the route X) that joins the road through the junction ramp and then exits to the exit ramp. By calculating larger than the increase value due to the above, it is possible to take into consideration the driver's burden reduction due to the crossing with other vehicles entering from the junction ramp. Therefore, in the road structure as described above, it is less likely than before that a route that merges with the merge ramp through the road and then exits the exit ramp is calculated as a guide route.

  In addition, the vicinity here means satisfying a predetermined proximity criterion. In addition, the proximity criterion is a criterion that is advantageous in that the shorter the physical distance or the psychological distance during driving, the more it is satisfied. As the proximity reference, for example, “the distance along the road is within a reference distance (for example, 500 meters)”, “the distance along the road is the first predetermined distance (for example, 500 meters) and the first predetermined distance, for example. For example, the distance is within a reference distance randomly selected each time between longer second predetermined distances (for example, 700 meters), “connected by a road that does not meet or branch between”, and the like.

  In addition, this navigation device determines whether or not (3) the traveling lane of the host vehicle on the road Z is in a lane that does not contact the side where the exit ramp branches from the road Z, and the above three determinations When the result of this and the fifth determination result are both affirmative, the increase value of the total cost of the route X due to the existence of the exit route is negative even if one of these three determination results It is to make it larger than. By doing in this way, the navigation apparatus can perform the guidance route calculation in consideration of the reduction of the burden on the driver due to the crossing with the other vehicle more finely based on the traveling lane of the own vehicle.

  In addition, the navigation device [the route for exiting from the multiple lane road to the exit ramp after the merge with the merge ramp on the multiple lane road is calculated as the guide route, and the merge ramp is Based on the fact that the exit ramp is joined from the same side as the branch side in the vicinity of the branch point to the exit ramp on the multi-lane road], the merge warning to the driver before the branch point Processing for performing guidance may be performed.

  As a result, even if the route calculation as described above is performed, the driver is warned of the joining even if the route to the exit road becomes a guide route as a result. By doing so, the driver's attention can be alerted.

  The first feature of the present invention is that a route for calculating a route with a low total cost as a guide route among routes to the destination, and a route for the guide route calculated by the guide route calculation function. A program that causes a computer to realize a route guidance function for performing guidance, and the guidance route calculation function is located in front of the branch point in the route X including the exit route that exits from the branch point of a certain multi-lane road Z to the exit ramp. An approach path determination function for determining whether or not the route has entered from the road Z with respect to a junction between the road Z and the junction ramp in the vicinity of the road, and a side where the exit ramp of the road Z branches And the connection direction determination function for determining whether or not the side where the merge lamp merges with the road Z is the same side, the approach path determination function, and the connection direction determination function Based on making an affirmative determination, an increase in the total cost of the route X due to the presence of the exit route is compared with a case where one of the approach route determination function and the connection direction determination function makes a negative determination. And an increased cost increase value specifying function.

  A second feature of the present invention is that a navigation device that calculates a route with a low total cost among routes to a destination as a guide route and performs route guidance for the calculated guide route is provided on a certain road Z. The route X enters from either the road Z or the junction ramp with respect to the junction of the road Z and the junction ramp before the junction in the route X including the exit route that exits from the junction to the exit ramp. In the special cost increase value data stored in the storage medium, the increase value of the cost of the route X due to the existence of the exit route is specified based on the cost increase value corresponding to the determination result. It is that. Here, the special cost increase value data is the road in the road structure in which there is an exit ramp that branches from the road Z to the same side as the merge ramp after the merge ramp merges with the road Z having a plurality of lanes. It is data indicating a cost increase value due to the existence of a exit route that exits from Z to the exit ramp, and is associated with an entry source of the road Z and the junction ramp to the junction. The association means data that is larger when the approach is from the road Z than when the approach is from the merge ramp. Specific examples of association are: (1) Assign a cost increase value p when entering from the road Z, and assign a cost increase value q (p> q) when entering from the junction ramp. For example, the cost increase value p is assigned only when entering from the road Z.

  Such a navigation device has a special cost increase value data in a road structure in which there is an exit ramp that branches from the road Z to the same side as the merge ramp after the merge ramp merges with the road Z having a plurality of lanes. (A) Increase in the cost value of a route (corresponding to the route X) that joins the joining ramp through the road Z and then exits to the exit ramp by exiting to the exit ramp (B) exit to the exit ramp of the cost value of a route (which also corresponds to the route X) that joins the road Z through the junction ramp and then exits to the exit ramp. By calculating a larger value than the increase value due to the above, the risk of crossing with other vehicles entering from the junction ramp is taken into consideration. Therefore, in the road structure as described above, it is less likely than before that a route that merges with the merge ramp through the road Z and then exits to the exit ramp is calculated as a guide route.

  The feature of the present invention can also be understood as map data for a navigation device that stores special cost increase value data as described above. Furthermore, it can also be understood as a program that uses the special cost increase value data as described above.

(First embodiment)
The first embodiment of the present invention will be described below. FIG. 1 shows a hardware configuration of a vehicle navigation apparatus 1 according to this embodiment. The vehicle navigation apparatus 1 includes a position detector 11, an operation switch group 12, an image display device 13, a speaker 14, a RAM 16, a ROM 17, an external storage medium 18, and a CPU 19.

  Each of the position detectors 11 includes a well-known sensor (not shown) such as a geomagnetic sensor, a gyroscope, a vehicle speed sensor, a steering angle sensor, and a GPS receiver. Information for specifying the current position and orientation is output to the CPU 19.

  The operation switch group 12 includes a plurality of mechanical switches provided in the vehicle navigation device 1 and an input device such as a touch panel provided so as to overlap the display surface of the image display device 13. A signal based on the touch is output to the CPU 19.

  The image display device 13 displays a video based on the video signal output from the CPU 19 to the user. Examples of the display image include a map centering on the current location.

  The external storage medium 18 is a non-volatile storage medium such as an HDD, and stores a program read and executed by the CPU 19, map data for route guidance, and the like.

  The map data includes road data and facility data including link and node positions, types, lane information, link and node connection relation information, and the like. The connection relation information includes information such as which link is connected to which node, and each link connected to each node is in which direction the node branches from that node. The lane information includes data such as the number of lanes of each link, each lane width, each lane position, and which link each lane can be connected to.

  A CPU (corresponding to a computer) 19 executes a program for the operation of the vehicle navigation apparatus 1 read from the ROM 17 and the external storage medium 18, and from the RAM 16, the ROM 17, and the external storage medium 18 at the time of execution. Information is read, information is written to the RAM 16 and the external storage medium 18, and signals are exchanged with the position detector 11, operation switch group 12, image display device 13 and speaker 14.

  Specific processes performed by the CPU 19 executing the program include a current position specifying process, a guide route calculating process 20, a route guide process 21, and the like.

  The current position specifying process is a process for specifying the current position and direction of the vehicle based on a signal from the position detector 11 using a known technique such as map matching.

  The guide route calculation process 20 is a process for calculating an optimum guide route from the current position to the destination. The guidance route calculation process 20 is performed when the user inputs a destination from the operation switch group 12 or when the host vehicle deviates from the guidance route guided by the route guidance process 21. 20 is starting.

  The route guidance processing 21 reads map data from the external storage medium 18, and displays an image in which the calculated guidance route, destination facility, transit facility, current position, etc. are superimposed on the map indicated by the map data on the image display device 13. This is a process for outputting to the speaker 14 a guidance voice signal for instructing a right turn, a left turn, a lane movement or the like when necessary, such as when the host vehicle reaches a predetermined distance before the guidance intersection. In the route guidance process 21, the CPU 19 performs various types of guidance based on guidance data created in advance when the guidance route calculation process 20 is executed. This guidance data is data for designating what kind of guidance image or guidance sound is to be displayed on the image display device 13 or the speaker 14 when the host vehicle reaches which position on the guidance route.

  3 and 4 show flowcharts of the program 100 and the program 200 executed by the CPU 19 for the guidance route calculation processing 20 and the like. The program 100 is a program that is executed by the CPU 19 when an input of a destination by a user is received from the operation switch group 12. The program 200 is a program that is repeatedly executed while the CPU 19 is executing the route guidance process 21.

  Hereinafter, taking the road structure as shown in FIG. 1 as an example, the operation of the CPU 19 that executes the program 100 and the program 200 will be described. In the road structure shown in FIG. 1, the exit ramp 43 branches from the highway main line 41 on one side of the two lanes to the right, and immediately after that the merge lamp 42 merges with the highway main line 41 from the right side, and the expressway starts from the junction point 50. The exit ramp 44 branches off from the main highway 41 at a branch point 49 separated by a distance γ along the main line 41. The exit lamp 43 and the exit lamp 44 inevitably join together and then connect to the road 45.

  In executing the program 100, first, in step 110, the CPU 19 calculates a provisional guidance route from the current position to the destination. In the calculation of the temporary guidance route, the cost of each route is calculated for a plurality of routes from the current position to the destination, and the route with the lowest cost is selected as the guidance route. As a method for calculating a guidance route using such a cost, for example, there are a Dijkstra method, a method using a genetic algorithm, and the like. In calculating the cost of a certain route, for example, the cost of the link is calculated for each link constituting the route, and the total cost of the link is the cost of the route. The cost of a link includes various factors such as the length of the link, type (highway, arterial road, narrow street, etc.), presence or absence of traffic congestion, and whether the link is a link immediately after a right or left turn along the route. It depends on the conditions.

  Subsequently, in step 120, it is determined based on the map data whether or not the provisional guidance route calculated in step 110 includes a route that exits from the main line (corresponding to the road Z). The main line referred to here is a basic road that connects cities such as a highway and a toll road, and is composed of a plurality of lanes on one side. In addition, exiting from the exit means that the exit ramp branches off from the main line and the main line exits from the branch point. Here, the exit refers to a branch point between the main line and the exit ramp. For example, in FIG. 1, the route from the main line to the exit refers to a route that enters the exit ramp 44 from the highway main line 41. If there is a route from the main line to the exit, step 130 is executed. If there is no such route, the current provisional guidance route is set as the guidance route, and then the execution of the program 100 is terminated.

  In step 130, it is determined whether or not there is a meeting point within a predetermined distance β from the exit specified in step 120 along the temporary guidance route. Here, the “merging point” refers to a point where a main line and a confluence ramp to the main line merge. Here, β is a distance that is a boundary (whether or not the driver can change the lane for leaving the exit ramp with a margin even if there is a vehicle entering from the junction ramp). For example, 500 meters). In FIG. 1, the determination result is affirmative because there is a merging point 50 at a distance γ (where γ <β) from the exit (that is, the branch point 49). If the result of this determination is affirmative, step 135 is subsequently executed. If the result is negative, the current provisional guidance route is set as the guidance route, and then the execution of the program 100 is terminated.

  In step 135, it is determined whether or not the junction lamp and the exit lamp are connected to the same side of the main line. Specifically, for each of the confluence ramp and exit ramp, determine whether it is connected to the right side or the left side with respect to the running direction of the main line, and if both are connected to the right side, and both are on the left side It is determined that the merge lamp and the exit lamp are connected to the same side of the main line only when they are connected to the main line. Moreover, it is specified based on the connection relation information of the link in a map data, and which of the driving | running | working direction of a main line is connected to a joining lamp and a leaving lamp. That is, three links connected to a junction or exit node, that is, a main link on the side that enters the node along the temporary guidance route (hereinafter referred to as an incoming main link), from the node along the temporary guidance route For each of the main link on the exit side (hereinafter referred to as “exit main link”) and the link corresponding to the ramp (hereinafter referred to as “ramp link”), the direction from the node is read from the connection relationship information, and the relationship of the direction is determined. Based on this, it is specified whether the lamp is connected to the right side or the left side with respect to the traveling direction of the main line. For example, in the case of FIG. 1, both the merge lamp 42 and the exit lamp 44 are connected to the right side with respect to the traveling direction of the highway main line 41.

  If it is connected to the same side, step 140 is subsequently executed. If it is not connected to the same side, the current provisional guide route is set as the guide route, and then the execution of the program 100 is ended.

  In step 140, it is determined whether or not the provisional guidance route enters the junction from the main line. The case where the temporary guide route does not enter the junction from the main line corresponds to the case where the temporary route enters the junction from the junction ramp. For example, in FIG. 1, the route 46 is a route entering the junction from the main line, and the route as indicated by the arrow 60 is a route entering the junction from the junction ramp. If the main line enters the junction, step 145 is executed. If the main line does not enter the junction, the current temporary guidance route is set as the guidance route, and then the execution of the program 100 is terminated.

  In step 145, the cost of the link that passes through the exit to exit the main line, that is, the link of the exit ramp, is larger by a positive number α than usual (that is, when used in route calculation in step 110). To do.

  Subsequently, in step 150, the guidance route from the current position to the destination is calculated again in such a state that the cost of the exit ramp link has increased. At this time, the cost of the route passing through the exit ramp increases by α as compared with the time of calculation in step 110, so that it is difficult to calculate as the guidance route.

  Subsequently, in step 160, it is determined in the same manner as in step 120 whether or not the guidance route calculated in step 150 includes a route that exits from the main line to the exit. If there is a route from the main line to the exit, step 170 is subsequently executed, and if there is no such route, execution of the program 100 is terminated.

  In step 170, it is determined in the same manner as in step 130 whether or not there is a junction point within the predetermined distance β from the exit specified in step 160 along the temporary guidance route. When the result of this determination is affirmative, step 175 is subsequently executed, and when negative, execution of the program 100 is terminated.

  In step 175, it is determined in the same manner as in step 135 whether or not the merge lamp and the exit lamp are connected to the same side of the main line. If it is connected to the same side, then step 180 is executed. If it is not connected to the same side, the execution of the program 100 is terminated.

  In step 180, it is determined in the same manner as in step 140 whether or not the provisional guidance route enters the junction from the main line. If the merging point is entered from the main line, then step 185 is executed. If the merging point is not entered from the main line, the execution of the program 100 is terminated.

  In step 185, a merging warning is prepared. Specifically, in the above route guidance process, before entering the junction point specified in step 170, such as “crossing the junction. Guidance data is created so that warning alert text data and audio data are output to the image display device 13 or the speaker 14.

  When the CPU 19 executes the program 100 as described above, the vehicle navigation device 1 calculates a provisional guidance route to the destination set by the user (see step 110), and (1) the provisional guidance route. Whether or not a route exiting the exit ramp from the main road is included (see step 120), (2) a confluence ramp that joins the main route within a predetermined distance β from the exit to the exit ramp along the temporary guidance route (See step 130), (3) whether the merge lamp and exit lamp are on the same side of the main line (see step 135), and (4) the provisional guidance path merges with the main line If all four determination results, whether or not the main line has entered the junction with the ramp (see step 140), are affirmative, the link exiting the main line to the exit ramp Cost, (see step 145) and plus positive number α to that used in the first path calculation in step 110, again calculates the guide route by using the new cost (see step 160).

  Note that the case where all of the above conditions (1) to (4) are satisfied, that is, in the vicinity of a branch point before the branch point in the route X including the exit route that exits from the branch point of a certain one-lane multiple lane road to the exit ramp. The side where the route X enters from the road with respect to the junction of the road and the junction ramp and the exit ramp of the road branches, and the side where the junction ramp joins the road Corresponds to the case where the two are on the same side. If this condition is not satisfied, that is, if any one of the above (1) to (4) is not satisfied, the link cost is not increased and the guidance route is not recalculated. Therefore, the increase value of the total cost of the route X due to the exit ramp from the main line to the exit included in the route X is compared with the case where any one of the above (1) to (4) is not satisfied ( The case where all of 1) to (4) are satisfied is larger.

  By such an operation, the vehicle navigation apparatus 1 is located on the same side as the merge lamp 42 from the road in the vicinity after the merge lamp 42 merges with the highway main line 41 having a plurality of lanes as shown in FIG. In a road structure in which there is an exit ramp 44 that branches to (A) the exit ramp 44 of the cost value of a route that merges with the junction ramp 42 through the main highway 41 and exits to the exit ramp 44. (B) The cost value of the route that merges with the highway main line 41 through the merge ramp 42 and exits to the backward exit ramp 44 is due to exiting to the exit ramp 44. By calculating larger than the increase value, the risk of crossing with other vehicles entering from the junction ramp is taken into consideration. Therefore, in the case of FIG. 1, the vehicle navigation apparatus 1 uses a route 46 that enters the road 45 through the junction point 50 and the branch point 49 as a guide route from the lower left of the highway main line 41 to the facility ahead of the road 45. However, there is a higher possibility of selecting the route 47 that enters the road 45 through the exit ramp 43 and the route 48 that continues to travel on the main highway 41 after passing the junction point 50 and the branch point 49.

  Further, the vehicular navigation device 1 recalculates the guidance route even if the guidance route recalculated in this way satisfies all of the above (1) to (4) (see steps 160 to 180). First, a preparatory process for performing a merge warning guidance to the driver before the merge lamp is performed (see step 185).

  In this way, even if the guidance route calculation as described above is performed, even if the route that exits to the exit lamp 44 becomes the guidance route, the driver is warned of joining. In this way, the driver's attention can be drawn.

  Further, in the execution of the program 200, the CPU 19 first determines in step 210 whether or not the host vehicle has deviated from the current guidance route based on the positional deviation between the current position identified by the current position identification process and the guidance route. Judgment based on. If it is determined that the vehicle has deviated from the guidance route, step 215 is subsequently executed. If it is determined that the vehicle has not deviated, execution of the program 200 is terminated.

  In step 215, a temporary guidance route from the deviated position, that is, the current position to the initial destination is calculated.

  Subsequently, in step 220, as in step 120 of the program 100, it is determined whether or not there is a route from the main line (corresponding to the road Z) to the exit in the calculated temporary guidance route. If there is a route exiting from the main line to the exit, step 235 is subsequently executed. If there is no such route, the provisional guidance route is set as the guidance route, and then the execution of the program 200 is terminated.

  In step 235, it is determined in the same manner as in step 130 whether or not a junction point exists within the predetermined distance β from the exit identified in step 220 along the temporary guidance route. When the result of this determination is affirmative, step 240 is subsequently executed, and when negative, the provisional guidance route is set as the guidance route, and then the execution of the program 200 is terminated.

  In step 240, it is determined in the same manner as in step 135 whether or not the junction lamp and the exit lamp are connected to the same side of the main line. If it is connected to the same side, step 245 is subsequently executed. If it is not connected to the same side, the provisional guide route is set as the guide route, and then the execution of the program 200 is ended.

  In step 245, it is determined in the same manner as in step 140 whether or not the provisional guidance route enters the junction from the main line. When entering the junction from the main line, step 255 is subsequently executed, and when not entering the junction from the main line, the provisional guidance route is set as the guidance route, and then the execution of the program 200 is terminated.

  In step 255, it is determined whether or not the host vehicle is traveling in a lane on the main line that needs to change lanes in order to exit from the exit specified in step 220. A lane that requires a lane change to exit is an lane that is not in contact with the exit ramp. For example, in the highway main line 41 of FIG. 1, the left lane corresponds to this. If the vehicle is traveling on a lane that requires a lane change, step 260 is subsequently executed. If the vehicle is not traveling, the provisional guide route is set as the guide route, and then the execution of the program 200 is terminated.

  The lane in which the host vehicle is traveling is identified by, for example, a current position from RTK (real-time kinematic) -GPS that can identify the current position with an error of several centimeters as a GPS receiver of the position detector 11. This can be realized by comparing the information with the lane information in the map data. In addition, when an existing position on the road in the past driving route of the own vehicle can be specified with an accuracy of about the lane width (for example, an ETC gate in which a position having an accuracy of about the lane width is described in the map data) The current position is determined with accuracy of the lane width by self-contained navigation using the vehicle speed sensor, steering angle sensor, geomagnetic sensor, gyroscope, etc. of the position detector 11 starting from that position. The lane in which the host vehicle is traveling may be specified by comparing the position with the lane information of the map data.

  In step 260, the cost of the link that passes through the exit to exit the main line, that is, the link of the exit ramp, is larger by a positive number α than normal (that is, when used in route calculation in step 215). To do.

  Subsequently, in step 270, the guidance route from the current position to the destination is calculated again in such a state that the cost of the exit ramp link has increased. At this time, the total cost of the route passing through the exit ramp increases by α as compared with the time of calculation in step 215, so that it is difficult to calculate as a guide route.

  Subsequently, in step 270, it is determined in the same manner as in step 220 whether or not the guidance route calculated in step 260 includes a route that exits from the main line to the exit. If there is a route from the main line to the exit, step 275 is subsequently executed. If there is no such route, the execution of the program 200 is terminated.

  In step 275, it is determined in the same manner as in step 235 whether or not there is a junction point within the predetermined distance β from the exit specified in step 270 along the temporary guidance route. When the result of this determination is affirmative, step 280 is subsequently executed, and when negative, execution of the program 200 is terminated.

  In step 280, it is determined in the same manner as in step 240 whether or not the merge lamp and the exit lamp are connected to the same side of the main line. If it is connected to the same side, then step 180 is executed. If it is not connected to the same side, the execution of the program 200 is terminated.

  In step 285, it is determined in the same manner as in step 245 whether or not the provisional guidance route enters the junction from the main line. If the main line has entered the junction, step 290 is subsequently executed. If the main line has not been entered, the execution of the program 200 is terminated.

  Step 290 performs a merge warning process. Specifically, in the above route guidance process, before entering the merge point identified in step 270, such as “crossing the merge. Guidance data is created so that warning alert text data and audio data are output to the image display device 13 or the speaker 14.

  When the CPU 19 executes the program 200 as described above, when the vehicle leaves the current guidance route (see step 210), the vehicular navigation device 1 displays a provisional guidance route from the departure point to the destination. Calculate (see step 215). Then, for the newly calculated provisional guidance route, (1) whether or not the provisional guidance route includes a route from the main road to the exit ramp (see step 220), (2) from the exit to the exit ramp Whether there is a merge lamp that merges with the main line within a predetermined distance β from the temporary guidance route (see step 235), (3) whether the merge lamp and the exit ramp are on the same side of the main line (See step 240), (4) whether or not the provisional guidance route has entered the junction of the main line and the merge ramp from the main line (see step 245), and (5) the current vehicle on the main road If all of the five determination results are whether the driving lane is in a lane far from the side where the exit ramp branches off from the main road, the link of the link exiting the main ramp to the exit ramp is positive. Preparative (see Step 260) a positive number α in addition to those used in the route calculation step 215 again calculates a guide route by using the new cost (see step 265).

  By such an operation, when the vehicle navigation apparatus 1 performs route guidance using the route 47 passing through the exit ramp 43 in a plurality of lanes as shown in FIG. 1, the vehicle does not follow the guidance. If it is determined that (1) to (4) are satisfied in steps 220 to 245 described above when the vehicle has traveled on the highway main line 41 without entering the exit ramp 43, the traveling lane of the own vehicle is subsequently determined. If it is specified and it is the right lane, a negative determination is made in step 255, and if it is the left lane, a positive determination is made in step 255. When this affirmative determination is made, the cost increase value due to exiting from the route 47 to the exit ramp 44 is calculated to be higher than when the negative determination is made, so The risk of crossing with the vehicle will be considered in more detail based on the driving lane. Therefore, in the case of FIG. 1, the vehicular navigation apparatus 1 uses the branch point 49 as a guide route to the facility ahead of the road 45 on the highway main line 41 rather than the route 46 that enters the exit ramp 44 via the branch point 49. The possibility of selecting the route 48 that continues to travel on the highway main line 41 past the road becomes higher.

  Further, when there is one that is not satisfied among the above (1) to (5), the link cost is not increased and the guidance route is not recalculated. Therefore, the increase value of the total cost of the route X due to the exit ramp from the main line to the exit included in the route X is compared with the case where any one of the above (1) to (5) is not satisfied ( The case where all of 1) to (5) are satisfied is larger. Further, the vehicular navigation device 1 recalculates the guidance route even if the guidance route calculated again in this way satisfies all of the above (1) to (5) (see steps 270 to 285). First, a preparatory process for performing the merge warning guidance to the driver before the exit lamp is performed (see step 290).

In this way, even if the guidance route calculation as described above is performed, even if the route that exits to the exit lamp 44 becomes the guidance route, the driver is warned of joining. In this way, the driver's attention can be drawn.
(Second Embodiment)
Next, a second embodiment of the present invention will be described. The configuration of the vehicle navigation device 1 according to the present embodiment is the same as that of the first embodiment except for the contents of the map data. The operation of the vehicle navigation device 1 is the same as that of the first embodiment except for the cost calculation method in the guidance route calculation process. Hereinafter, the difference between the vehicle navigation device 1 of the present embodiment and the vehicle navigation device 1 of the first embodiment will be described.

  The map data included in the vehicle navigation device 1 of the present embodiment has a special cost increase value data table in addition to the map data of the first embodiment. The special cost increase value data table includes a plurality of entries, and each entry associates special cost increase value data with one specific link on the map. Here, the specific link means the exit in the road structure in which there is an exit ramp that branches from the road to the same side as the junction ramp in the vicinity after the junction ramp joins a road having multiple lanes. It is the link of the lamp. For example, in FIG. 1, the exit lamp 44 corresponds to a specific link. FIG. 5 visually shows the configurations of the links L1 to L7 and the nodes N1 to N8 included in the map data corresponding to the road configuration of FIG. Links L 1, L 3, L 4 and L 5 are links of the highway main line 41, link L 6 is a link of merging ramp 42, link L 7 is a link of merging ramp 42, and link L 2 is a link of exit ramp 44. . Further, the node N4 corresponds to the node of the junction point 50, and the node N3 corresponds to the node of the branch point 49. Therefore, the specific link is the link L2. The special cost increase value data is positive value data indicating a cost increase value due to the existence of an exit route that exits from the road to the exit ramp.

  Further, the CPU 19 of the present embodiment is configured to execute the program 100 and the program 200 in the first embodiment. However, with respect to the program 100, steps 110 to 145 are not executed, but are first executed from step 150. In addition, for the program 200, steps 210 to 260 are not executed, but are first executed from step 265. In the guidance route calculation in step 150 and step 265, as in the first embodiment, in the route guidance process 21, the cost of each route that is a candidate for the guidance route (hereinafter referred to as a candidate route) is calculated. As a result, the route with the lowest cost is set as the guide route. Further, when calculating the cost of each candidate route, the cost of each link constituting the candidate route is calculated individually. In this embodiment, in particular, the cost is associated with the special cost increase value data table. For the cost of a certain link, the cost of that link is calculated by executing the program 300 shown in FIG. That is, the CPU 19 first calculates the cost for the specific link based on the distance of the node in step 305, and then in step 310, the node immediately preceding the current cost calculation symmetrical path (in FIG. 5). It is determined whether or not the main line (corresponding to link L4 in FIG. 5) has entered the node N4). If the main line has been entered, then step 230 is executed, and the main line has been entered. If not, the execution of the program 300 is terminated.

  In step 320, the special cost increase value data for the specific link is read from the special cost increase value data table. Subsequently, at step 330, the read special cost increase value data is added to the cost calculated at step 305, and the execution of the program 300 is terminated.

  When the CPU 19 executes such a program 300, the vehicle navigation apparatus 1 determines whether a route that is a candidate for a guidance route enters from a main line or a merging ramp with respect to a specific link. If the determination result is affirmative (see step 310), the cost of the link is increased (see step 330) based on the corresponding special cost increase value data (see step 320). Such a vehicle navigation apparatus 1 has special cost increase value data in a road structure in which there is an exit ramp that branches from the road to the same side as the merge ramp after the merge ramp merges on a road having a plurality of lanes. (A) The cost value of a route (corresponding to the route X) that joins the joining ramp through the road and then exits to the exit ramp is increased by exiting to the exit ramp. By (B) exiting to the exit ramp of the cost value of a route (which also corresponds to the route X) that joins the road through the junction ramp and then exits to the exit ramp By calculating larger than the increase value, the risk of crossing with other vehicles entering from the junction ramp is taken into consideration. Therefore, in the road structure as described above, it is less likely than before that a route that merges with the merge ramp through the road and then exits the exit ramp is calculated as a guide route.

  When creating the special cost increase value data table for map data, determine which links should be included in the special cost increase value data table after creating the map data excluding the special cost increase value data table, The map data is read, and the general-purpose computer exits from the road to the same side as the merging ramp in the vicinity (for example, within a predetermined distance β) after the merging ramp merges with the road having a plurality of lanes. A link of the exit ramp in the road structure where there is a ramp is searched from the map data, and a predetermined positive value α is associated with the link extracted as a result of the search, and this is added to the special cost increase value data. It may be a table.

  In the first and second embodiments described above, the CPU 19 executes steps 110 to 180 of the program 100 and steps 210 to 285 of the program 200 so as to function as a guidance route calculation unit. When executed, it functions as route guidance means. In addition, the CPU 19 functions as an approach path determination unit by executing steps 120, 130, and 140 of the program 100, functions as a connection direction determination unit by executing step 135, and costs by executing step 145. It functions as an increase value specifying unit, and functions as a merge warning processing unit by executing step 185.

  The CPU 19 functions as an approach path determination unit by executing steps 220, 235, and 245 of the program 200, functions as a connection direction determination unit by executing step 240, and travels by executing step 255. It functions as a lane determination unit, functions as a cost increase value specifying unit by executing step 260, and functions as a merge warning processing unit by executing step 290.

Further, the CPU 19 functions as an approach path determination unit by executing step 310 of the program 300, and functions as a cost increase value specifying unit by executing steps 320 and 330.
(Other embodiments)
In the above embodiment, as shown in the program 200, a new guidance route is calculated after the host vehicle leaves the guidance route. However, this need not always be the case. . For example, when the initial guidance route is calculated, it is assumed that the host vehicle has left the guidance route at multiple points on the guidance route, and the guidance route from the separated position to the destination is calculated in advance. Also good. Further, at the time of the departure, a plurality of patterns may be assumed in advance for the lane on which the host vehicle travels, and the guidance route may be calculated in advance for each of the plurality of patterns. By doing in this way, the guidance route calculation can be performed in advance while increasing the cost of the outgoing link in a situation where the determinations of steps 220 to 255 of the program 200 are all positive.

  In the above embodiment, the vehicle navigation device 1 is cited as an example of the navigation device of the present invention. However, the navigation system of the present invention is not limited to the vehicle navigation device, and for example, a person can carry it. It can also be realized as a portable navigation device.

  Note that the merge warning process as in each of the above embodiments may be performed in the situation illustrated in FIG. In FIG. 7, the exit ramp 51 from the expressway is connected to a general road 52 with three lanes on one side, and an intersection with a road 54 orthogonal to the general road 52 is 300 meters west from the connection position. When the guidance route calculated by the vehicle navigation device 1 is a route that enters the general road 52 from the exit ramp 51 and then turns right as indicated by an arrow 53 and enters the road 54, the driver is in a very short section. You must change lanes within. Therefore, when the vehicle navigation apparatus 1 detects that the lane change is necessary within a short distance after entering the multiple lanes on one side of the guidance route at the time of calculating the guidance route, When the host vehicle arrives, a warning may be given to the effect that the vehicle is approaching a point where lane change is difficult. In this way, the driver will not be bothered by difficult lane changes that suddenly appear.

The schematic which looked at the road structure which consists of the expressway main line 41 grade | etc. From the top is shown. It is a hardware block diagram of the vehicle navigation apparatus 1 which concerns on embodiment of this invention. It is a flowchart of the program 100 which CPU19 performs. It is a flowchart of the program 100 which CPU19 performs. It is a flowchart of the program 200 which CPU19 performs. It is a flowchart of the program 200 which CPU19 performs. It is a link and node block diagram in map data corresponding to the road structure shown in FIG. It is a flowchart of the program 300 which CPU19 performs. It is a road figure which shows the condition which does not change a lane immediately after approaching a multilane road.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle navigation apparatus, 11 ... Position detector, 12 ... Operation switch group,
13 ... Image display device, 14 ... Speaker, 16 ... RAM, 17 ... ROM,
18 ... External storage medium, 19 ... CPU, 20 ... guidance route calculation process, 21 ... route guidance process,
41 ... Highway main line, 42 ... Confluence ramp, 43 ... Exit ramp, 44 ... Exit ramp,
45 ... road, 46-48 ... route, 49 ... branch point, 50 ... confluence point,
51: Exit ramp, 52 ... General road, 53 ... Driving direction, 54 ... Road,
100, 200, 300... Program.

Claims (7)

A guide route calculating means for calculating a route with a low total cost as a guide route among routes to the destination;
Route guidance means for performing route guidance for the guidance route calculated by the guidance route calculation means,
The guidance route calculation means includes
With respect to the junction of the road Z and the junction ramp in the vicinity of the junction X in the route X including the exit route that exits from the junction of a certain multi-lane road Z to the exit ramp, the route X is the road Z An approach path determination means for determining whether the vehicle has entered from
A connection direction determination means for determining whether or not a side where the exit ramp of the road Z branches and a side where the merge lamp merges with the road Z are the same side;
Based on the fact that both the approach path determination means and the connection direction determination means make an affirmative determination, the increase value of the total cost of the route X due to the existence of the exit path is determined as the approach path determination means and the connection A navigation apparatus comprising: a cost increase value specifying unit that is larger than a case in which at least one of the direction determination units makes a negative determination. The guidance route calculation means includes travel lane determination means for determining whether the travel lane of the host vehicle in the road Z is in a lane that does not contact the side where the exit ramp branches off from the road Z,
The cost increase value specifying means is based on the fact that any one of the travel lane determining means, the approach route determining means, and the connection direction determining means makes an affirmative determination based on the presence of the exit route. 2. The increase value of the total cost is increased as compared with a case where at least one of the travel lane determination means, the approach path determination means, and the connection direction determination means makes a negative determination. The navigation device described in 1. The route of exiting from the one-side multiple lane road to the exit ramp after passing through the merge ramp on the one-side multiple lane road is calculated as the guide route, and the merge ramp is the Based on the fact that the exit ramp is joined from the same side as the branch side in the vicinity of the branch point to the exit ramp on the one-side multiple lane road, the driver is in front of the branch point. The navigation apparatus according to claim 1, further comprising a merge warning processing unit that performs processing for performing a merge warning guide. Guide route calculation means for calculating a route with a low total cost as a guide route among routes to the destination, and
A program that causes a computer to function as route guidance means for performing route guidance for the guidance route calculated by the guidance route calculation means,
The guidance route calculation means includes
With respect to the junction of the road Z and the junction ramp in the vicinity of the branch point in the route X including the exit route that exits from the junction of a certain multi-lane road Z to the exit ramp, the route is from the road Z. An approach path determination means for determining whether or not the vehicle has entered,
A connection direction determination means for determining whether or not a side where the exit ramp of the road Z branches and a side where the merge lamp merges with the road Z are the same side;
Based on the fact that both the approach path determination means and the connection direction determination means make an affirmative determination, the increase value of the total cost of the route X due to the existence of the exit path is determined as the approach path determination means and the connection A program having a cost increase value specifying unit that is larger than a case in which one of the direction determining units makes a negative determination. A guide route calculating means for calculating a route with a low total cost as a guide route among routes to the destination;
Route guidance means for performing route guidance for the guidance route calculated by the guidance route calculation means;
An exit route exiting from the road Z to the exit ramp in a road structure in which there is an exit ramp that branches from the road Z to the same side as the junction ramp after the junction ramp joins the road Z having a plurality of lanes The special cost increase value data indicating the cost increase value due to the presence of the road is associated with the approach source of the road Z and the junction ramp to the junction point, and the merge ramp is more likely to be entered from the road Z. And a storage medium storing so as to be larger than the case of entering from
The guidance route calculation means includes
An approach path for determining whether the path X enters from the road Z or the merging ramp with respect to a merging point with the merging ramp in the path X including the exit path that exits from the road Z to the exit ramp. A determination means;
In the special cost increase value data stored in the storage medium, a cost for specifying an increase value of the cost of the route X due to the existence of the exit route based on the cost increase value corresponding to the determination result of the approach route determination means And an increase value specifying means. An exit route exiting from the road Z to the exit ramp in a road structure in which there is an exit ramp that branches from the road Z to the same side as the junction ramp after the junction ramp joins the road Z having a plurality of lanes The cost increase value due to the presence of the road and the road that is associated with the road and the entrance to the junction of the junction ramp is the entrance from the road Z is the entrance from the junction ramp Map data for a navigation device having special cost increase value data that is larger than the case. Guide route calculation means for calculating a route with a low total cost as a guide route among routes to the destination, and
A program that causes a computer to function as route guidance means for performing route guidance for the guidance route calculated by the guidance route calculation means,
The guidance route calculation means includes
With respect to the junction of the road Z and the junction ramp before the junction in the route X including the exit route that exits from the junction of a certain road Z to the exit ramp, the route corresponds to the intersection of the road Z and the junction ramp. An approach path judging means for judging from which one has entered,
The special cost increase value data according to claim 6, wherein the cost increase value specifies an increase value of the cost of the route X due to the existence of the exit route based on a cost increase value corresponding to a determination result of the approach route determination unit. And a value specifying means.

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