Map information generation system

Abstract

This system provides a map information generation system that increases the likelihood of accurately determining whether or not a user has passed through an entrance or exit point. [Solution] A map information generation system is configured, comprising: a map information acquisition unit that acquires map information including information indicating links corresponding to road sections and information indicating the locations of entrances and exits of facilities located around the road sections; and a determination area generation unit that sets the size and position of a determination area for determining whether or not an entrance or exit has been passed, based on the positional relationship between the link closest to the entrance or exit and the entrance or exit, and adds it to the map information in association with the entrance or exit.

Description

Technical Field

[0001] The present invention relates to a map information generation system.

Background Art

[0002] Conventionally, a technique for making a plan regarding the entrance and exit of a facility is known. For example, Patent Document 1 discloses a technique for improving the post-exit guidance notified in front of an exit when attempting to exit from inside a facility to a road outside the facility through the exit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When guiding regarding the entrance and exit of a facility, it may be necessary to determine whether a vehicle has passed through the entrance and exit. Since the position of the vehicle can vary, when making such a determination, it is conceivable to set a determination area of a predetermined size at the position of the entrance and exit, and determine that the vehicle has passed through the entrance and exit when the trajectory of the vehicle passes through the determination area. In this case, if the size of the determination area is not appropriate, the determination accuracy of whether the vehicle has passed through the entrance and exit will be low.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a map information generation system that enhances the possibility of accurately determining whether a vehicle has passed through an entrance and exit.

Means for Solving the Problems

[0006] In one embodiment of the map information generation system, the system includes: a map information acquisition unit that acquires map information including information indicating links corresponding to road sections and information indicating the locations of entrances and exits of facilities located around the road sections; and a determination area generation unit that sets the size and position of a determination area for determining whether or not an entrance or exit has been passed, based on the link closest to the entrance or exit and the positional relationship of the entrance or exit, and adds it to the map information in association with the entrance or exit.

[0007] In other words, in the map information generation system, the size and position of the determination area are set based on the positional relationship between the link closest to the entrance / exit and the entrance / exit itself. Generally, typical vehicle trajectories and causes of misjudgments are categorized according to the positional relationship between the link closest to the entrance / exit and the entrance / exit; therefore, in the map information generation system, the size and position of the determination area are set according to this positional relationship. For this reason, compared to a configuration in which, for example, the size of the determination area is fixed regardless of this positional relationship, it is possible to increase the likelihood of accurately determining whether or not a vehicle has passed through an entrance / exit. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing the configuration of the map information generation system in this embodiment. [Figure 2] This diagram illustrates situations where map matching processing can induce misidentification. [Figure 3] This figure shows an example where the judgment area is set inappropriately. [Figure 4] This is a flowchart of the map information generation process. [Figure 5] This diagram shows an example of a case where links are set up within a facility. [Figure 6] This diagram explains why the size of the detection area is changed according to the distance between the entrance / exit and the nearest link. [Figure 7] This diagram explains why the size of the detection area is changed according to the distance between the entrance / exit and the nearest link. [Figure 8] This figure shows an example where the direction of the travel trajectory and the direction of the link are close. [Modes for carrying out the invention]

[0009] Here, embodiments of the present invention will be described in the following order. (1) Configuration of the map information generation system: (2) Map information generation process: (3) Other embodiments:

[0010] (1) Configuration of the map information generation system: The map information generation system in this embodiment is a system that generates information regarding entrances and exits to facilities based on map information showing road networks and facilities. Figure 1 is a block diagram showing the configuration of the map information generation system 10 according to the present invention. The map information generation system 10 is a server that can communicate with a vehicle 100. Although not shown, the map information generation system 10 can communicate with multiple vehicles.

[0011] In this embodiment, vehicle 100 functions as a probe car that collects the vehicle's driving history, and also functions as a vehicle that uses the generated map information with a navigation system. Of course, a vehicle having only one of these functions may also exist. Vehicle 100 according to this embodiment includes a communication unit 110, a positioning unit 120, and a control unit 130. Vehicle 100 also includes a storage medium (not shown) for recording map information 140 and driving history 150. The communication unit 110 is a wireless communication circuit for wireless communication with the map information generation system 10.

[0012] The control unit 130 is capable of executing various programs stored on a storage medium (not shown). These programs include a navigation program. The control unit 130 uses the navigation program to determine the vehicle's current location based on the output of the positioning unit 120 and to perform navigation processing to guide the vehicle to its destination. The map information 140 is the same information as the map information generated by the map information generation system 10 and is stored on the storage medium by download or other means for use. Details of the map information will be described later, but this map information is referenced by the control unit 130 and used for determining the vehicle's position and for navigation processing.

[0013] The driving history 150 is information indicating the driving history of the vehicle 100, and includes the history of the vehicle 100's location. Specifically, the control unit 130 records the location of the vehicle 100 at regular intervals or at regular intervals, associates it with the vehicle 100's identification information, and stores it on a storage medium as the driving history 150. In this embodiment, the driving history is a single history from the start to the end of the vehicle 100's driving, and the end point of the driving is considered to be a parking location. In addition, each location of the vehicle is associated with information indicating whether or not map matching was performed. If map matching was performed, the vehicle's location is on a road, and if map matching was not performed, the vehicle's location is off a road (for example, inside a facility such as a parking lot). The control unit 130 transmits the driving history 150 to the map information generation system 10 via the communication unit 110 at regular time intervals.

[0014] The positioning unit 120 includes positioning sensors such as a GNSS receiver, a vehicle speed sensor, and a gyro sensor. The GNSS receiver is a device that receives signals from the Global Navigation Satellite System. The GNSS receiver receives radio waves from navigation satellites and outputs a signal to calculate the current position of the vehicle 100 via an interface (not shown). The vehicle speed sensor outputs a signal corresponding to the rotational speed of the wheels of the vehicle 100. The gyro sensor detects the angular acceleration of the vehicle 100 turning in the horizontal plane and outputs a signal corresponding to the orientation of the vehicle.

[0015] During driving on a road, the control unit 130 identifies an autonomous navigation trajectory, which is the trajectory of a position estimated based on signals output from a vehicle speed sensor and a gyro sensor. Further, the control unit 130 can execute a map matching process for identifying on which link (road section) the vehicle is located based on the degree of coincidence between the shape of the link indicated by the map information recorded in the recording medium and the autonomous navigation trajectory. In the map matching process, when the vehicle is identified as being on a link, the position of the vehicle is identified as the position on the link. When the vehicle is not identified as being on a link, the position of the vehicle is identified based on the autonomous navigation trajectory.

[0016] Next, the map information generation system 10 will be described. The map information generation system 10 includes a control unit 20 including a CPU, a RAM, a ROM, etc., a recording medium 30, and a communication unit 40. The recording medium 30 records various programs and various data. The communication unit 40 is a wireless communication circuit for performing wireless communication with the vehicle 100. The control unit 20 executes various programs stored in the recording medium 30 and the ROM. As an example of this program, the control unit 20 can execute a map information generation program 21.

[0017] The recording medium 30 records map information 30a and a driving history 30b. The driving history 30b is information indicating driving histories 150 collected from a plurality of vehicles 100. The map information 30a includes node data indicating the positions of nodes corresponding to intersections on the road on which the vehicle travels, shape interpolation point data indicating the positions of shape interpolation points for specifying the shape of the road section between nodes, link data indicating the connection between nodes, and facility data indicating facilities existing on the road and its surroundings.

[0018] The facility data includes the location of the facility, polygon data indicating the shape of the facility, and entrance / exit data indicating the locations of the entrances and exits of the facility. The location of the facility is represented, for example, by the coordinates of the reference point of the facility. The polygon data is data indicating the two-dimensional shape of the facility. Specifically, information indicating a polygon showing the shape of the outer periphery of the facility (for example, information indicating vertices, etc.) is defined as the polygon data and associated with the facility data. Note that the name of the facility is associated with the facility data.

[0019] The entrances and exits of the facility are the entrance to the facility, the exit from the facility, or both. The location of the entrance / exit is defined by the coordinates of the reference point of the entrance / exit, for example, the center of the gate of the entrance / exit. The entrances and exits of the facility are usually located on the outer periphery of the polygon data indicating the shape of the facility, and the inside of the entrance / exit is a parking lot. In some cases, determination areas for determining whether a vehicle has passed through the entrance / exit are associated with the entrance / exit data. In the present embodiment, the determination area is defined by a polygon set so as to include the location of the entrance / exit. When the trajectory of vehicle 100 overlaps with the determination area, it is considered that vehicle 100 has passed through the entrance / exit associated with the determination area. The shape of the polygon indicating the determination area is not limited, but in the present embodiment, it is a semi-circular figure. Furthermore, the information indicating the entrance / exit is associated with information indicating the link connected to the entrance / exit (the link indicating the road section traveled immediately before entering the facility through the entrance / exit, the link indicating the road section traveled immediately after exiting the facility through the entrance / exit).

[0020] The map information generation system 10 has a function of setting the determination area and adding it to the map information 30a. Therefore, the determination area of the entrance / exit is set by the map information generation system 10, and information indicating the determination area is associated with the facility data of the added facility. If the facility has no set determination area, information indicating the determination area is not associated with the facility data.

[0021] The determination area is set so that if the trajectory of vehicle 100 overlaps with the determination area, the vehicle is considered to have passed through the entrance / exit. However, if the size of the determination area is inappropriate, it may be possible to misjudge whether or not the vehicle has passed through the entrance / exit. In particular, in a configuration that performs map matching processing as in this embodiment, the map matching processing may induce misjudgments.

[0022] Figure 2 illustrates a scenario in which map matching processing may induce misjudgment. Figure 2 shows facility F and the roads surrounding facility F. Facility F has entrance / exit exits G1 and G2 along road section R. Link Ln1, which corresponds to the road section, is a link with nodes N1 and N2 as its endpoints. In Figure 2, links are shown as dashed lines. Figure 2 also shows an example of a trajectory when a vehicle approaches facility F from outside, enters facility F through entrance / exit G1, and parks at parking point P, shown as a dashed line. Furthermore, in Figure 2, the position that the control unit 130 identified as the position of the vehicle moving along this trajectory is shown as a white circle. In other words, the control unit 130 recognized the sequence of white circles as the trajectory of the vehicle.

[0023] In Figure 2, the vehicle's trajectory is shown as a solid line when its position on the link was identified through map matching, and as a dashed line when the map matching process was not functioning and the vehicle's position on the link was not identified. In other words, in Figure 2, map matching was performed before position Pout, but not after position Pout.

[0024] In a map-matched state, even if the vehicle's actual position differs from the link's position, the vehicle is considered to be traveling on the link, and its position is determined on the link. Therefore, before position Pout, the vehicle's position is the position on the link, as shown by the solid line. On the other hand, when the vehicle moves off the road, such as when it enters facility F, map matching becomes impossible, and the vehicle's position is determined by autonomous navigation. However, since the map-matching process aims to determine the vehicle's position as a position on the link as much as possible, it is often not immediately determined that the vehicle is off the road when it moves off the road. For this reason, it generally takes time before the vehicle's position is determined by autonomous navigation.

[0025] Figure 2 shows an example where the start of autonomous navigation is delayed. Specifically, after position Pout, it takes time for position P1 to be identified by autonomous navigation, and the distance between position Pout and position P1 is longer compared to other trajectories. Also, the trajectory jumps. When such a trajectory jump occurs, the vehicle trajectory recognized by the control unit 130 (solid line or dashed line) differs from the actual vehicle trajectory (dashed line), and therefore may not overlap with the entrance / exit G1 that the vehicle passed through. For this reason, if the determination area is, for example, determination area A1 for entrance / exit G1 and determination area A2 for entrance / exit G2, as shown in Figure 2, and the diameter of the semicircle is approximately the same as the area of ​​entrance / exit G1 and G2, the vehicle trajectory identified by the control unit 130 will not overlap with the determination area. In this case, it is not possible to determine which entrance / exit the vehicle passed through to enter facility F.

[0026] Figure 3 shows an example similar to Figure 2, but where the diameter of the semicircle used as the determination area is increased, and the determination area is set to a position offset from the entrance / exit location. That is, in the example shown in Figure 3, it is assumed that determination area A3 is set for entrance / exit G1 and determination area A4 is set for entrance / exit G2. In this example, the vehicle trajectory identified by the control unit 130 jumps after position Pout and does not pass through entrance / exit G1. And because the position of entrance / exit G2 is shifted closer to entrance / exit G1, the vehicle trajectory passes through determination area A4. For this reason, in this example, it is incorrectly determined that the vehicle passed through entrance / exit G2.

[0027] As described above, if the size of the determination area is small, it is not possible to determine which entrance / exit the vehicle passed through to enter facility F. On the other hand, even if the determination area is made large, there is a possibility of misjudgment that the vehicle passed through an entrance / exit that it did not actually pass through. For this reason, the map information generation system 10 according to this embodiment is equipped with a configuration for setting the determination area so as to reduce the possibility of omissions or misjudgments in the determination by the determination area.

[0028] The control unit 20 can execute various programs stored in the storage medium 30 or ROM. In this embodiment, the control unit 20 can execute a map information generation program 21 as an example of such a program. When the map information generation program 21 is executed, the control unit 20 functions as a driving history acquisition unit 21a, a map information acquisition unit 21b, and a determination area generation unit 21c.

[0029] The driving history acquisition unit 21a has the function of acquiring driving history from the vehicle 100. That is, when the driving history 150 is transmitted from the vehicle 100, the control unit 20 acquires the driving history 150 via the communication unit 40 and saves it as driving history 30b in the storage medium 30.

[0030] The map information acquisition unit 21b has the function of acquiring map information that includes information indicating links corresponding to road sections and information indicating the locations of entrances and exits of facilities located around the road sections. In other words, the control unit 20 refers to the facility data in the map information 30a and processes facility data for which no determination area is associated. Then, the control unit 20 acquires the location of the facility based on the facility data to be processed and acquires link data indicating links adjacent to the facility.

[0031] The determination area generation unit 21c has the function of setting the size and position of a determination area for determining whether or not a user has passed through an entrance / exit, based on the positional relationship between the link closest to the entrance / exit and the entrance / exit, and adding it to the map information in association with the entrance / exit. Specifically, the control unit 20 identifies the position of the link indicated by the link data from the position of the node which is the endpoint of the link, and identifies the link closest to the entrance / exit based on the position of the entrance / exit indicated by the facility data. Then, the control unit 20 sets the size and position of the determination area based on the positional relationship between the link and the position of the entrance / exit, and adds it to the map information 30a in association with the entrance / exit.

[0032] Details of the process for setting the size and position of the determination area will be described later, but the trajectory of a vehicle passing through the determination area is categorized into typical patterns based on the link closest to the entrance / exit and the entrance / exit itself. Therefore, in this embodiment, the control unit 20 adjusts the size of the determination area so that typical trajectories are included within the determination area. As a result, the likelihood of accurately determining whether or not a vehicle has passed through an entrance / exit can be increased.

[0033] (2) Map information generation process: Figure 4 is a flowchart showing the map information generation process that generates map information related to the judgment area. The map information generation process may be performed when generating map information 30a, or it may be performed at the timing of updating map information 30a in conjunction with facility data updates. In either case, the map information generation process is performed for each facility for which information indicating the judgment area is not associated.

[0034] There may be multiple target facilities. Also, there may be multiple entrances and exits within the same facility. Therefore, there is one or more, and often multiple, entrances and exits for which a judgment area should be set. When the map information generation process starts, the control unit 20 selects an entrance / exit using the function of the map information acquisition unit 21b (step S100). That is, the control unit 20 selects one entrance / exit from among the entrances and exits for which a judgment area should be set that has not been processed in steps S100 to S145 as the target for processing.

[0035] Next, the control unit 20 determines whether the location of the entrance / exit is on a link, based on the function of the determination area generation unit 21c (step S105). Specifically, the control unit 20 refers to the map information 30a and identifies the location of the entrance / exit to be processed, which was selected in step S100. The control unit 20 also refers to the map information 30a and identifies the link closest to the entrance / exit, and determines whether the location of the entrance / exit is on a link.

[0036] In step S105, if it is determined that the entrance / exit location is on the link, the control unit 20 sets the size of the determination area to the minimum value and sets the center of the determination area to the entrance / exit location using the function of the determination area generation unit 21c (step S110). The size of the determination area has a lower limit and an upper limit, and if the entrance / exit location is on the link, the size of the determination area is set to the lower limit. With this configuration, when the entrance / exit location is on the link, the size of the determination area is set to be smaller than when the entrance / exit location is not on the link. Furthermore, the control unit 20 sets the center of the determination area (the center of the circle when the determination area is considered to be a semicircle) to the entrance / exit location. Information indicating the set size and location of the determination area is added to the map information 30a, associated with the entrance / exit selected in step S100.

[0037] If the entrance / exit locations lie on links, the position of a vehicle passing through an entrance / exit location is highly likely to be identified on the link through map matching processing. This situation can occur when links are also set up within the facility. Figure 5 shows that links, indicated by dashed lines, are set up within facility F, including links from road R to links within facility F, and links passing through entrance / exit locations G1 and G2. In this configuration, the control unit 130 can identify the position of a vehicle on the links within facility F and on the links from road R to facility F through map matching processing. When map matching is performed on links, the position of a vehicle is identified on the link, so the determination area only needs to overlap with the link. For this reason, the size of determination areas A5 and A6 can be minimal and set to the lower limit. With this configuration, it is possible to determine with high accuracy whether a vehicle entering facility F from road R or exiting facility F to road R has passed through an entrance / exit location. Furthermore, it is possible to reduce the possibility of a vehicle that has not passed through an entrance / exit location being incorrectly determined to have passed through.

[0038] On the other hand, if it is not determined in step S105 that the location of the entrance / exit is on a link, the control unit 20 uses the function of the determination area generation unit 21c to determine whether or not the nearest link exists within a range of the entrance / exit location that is less than or equal to a first threshold (step S115). Specifically, the control unit 20 refers to the map information 30a and obtains link data for the link connected to the entrance / exit selected in step S100. The control unit 20 also identifies the link closest to the entrance / exit based on this link data. The control unit 20 then identifies the distance between the location of the entrance / exit and the link closest to it, and if this distance is less than or equal to a first threshold, it determines that the nearest link exists within a range of the entrance / exit location that is less than or equal to a first threshold. The distance between the entrance / exit and the link may be determined by the distance of a perpendicular line drawn from the entrance / exit to the link, etc.

[0039] In step S115, if it is determined that the nearest link is within a range of the entrance / exit location that is less than or equal to the first threshold, the control unit 20 uses the function of the determination area generation unit 21c to set the size of the determination area according to the distance between the entrance / exit and the link, and sets the center of the determination area to the location of the entrance / exit (step S120). At this time, the control unit 20 increases the size of the determination area the closer the distance between the link closest to the entrance / exit and the entrance / exit is to the entrance / exit. However, the control unit 20 sets the size of the determination area so that it does not exceed the upper limit and does not fall below the lower limit.

[0040] Figures 6 and 7 are diagrams that explain the reason for changing the size of the determination area according to the distance between the entrance / exit and the link closest to the entrance / exit. Figure 6 shows an example where the distance L1 between the entrance / exit and the link closest to the entrance / exit is small, and Figure 7 shows an example where the distance L2 between the entrance / exit and the link closest to the entrance / exit is large.

[0041] In Figures 6 and 7, the angle (the acute angle) α between the travel trajectory O1 and link Ln1, which is formed by a jump in position when transitioning from a map-matched state to a non-map-matched state, is defined. As shown in Figure 7, when the entrance / exit is far from link Ln1, the angle α is closer to 90° than when the entrance / exit is close to link Ln1, as shown in Figure 6. Thus, the closer facility F is to link Ln1, the more the angle α of the travel trajectory O1 deviates from 90°.

[0042] The greater the deviation of the angle α of the travel trajectory O1 from 90°, the higher the probability that the travel trajectory O1 will pass a position far from the entrance / exit. Therefore, in this embodiment, the size of the determination area is configured to increase as the distance between the link closest to the entrance / exit and the entrance / exit becomes smaller. Such a configuration can be realized by various configurations, and in this embodiment, the size of the determination area (the diameter of the semicircle) is predetermined to correspond to the distance between the link closest to the entrance / exit and the entrance / exit. Therefore, the control unit 20 identifies the size corresponding to the distance between the link closest to the entrance / exit and the entrance / exit, and sets the size of the determination area to that size.

[0043] Furthermore, the control unit 20 sets the position of the determination area so that the center of the determination area (the center of the circle when the determination area is considered to be semicircular) is at the position of the entrance / exit. In Figure 6, the determination areas A7 and A8 set as described above are shown, and in Figure 7, the determination areas A9 and A set as described above are shown. 10 This demonstrates the above configuration. With this configuration, the possibility of misjudgment occurring when transitioning from a map-matched state to a non-map-matched state can be reduced.

[0044] In this embodiment, there is an upper limit to the size of the determination area. The upper limit can be determined by various methods. In the map information 30a, the upper limit is the size of the determination area when the distance between the entrance / exit and the nearest link is the minimum value. Furthermore, the upper limit of the determination area may be set in relation to the surrounding features. For example, as shown in Figure 6, when entrance / exit G1 and G2 are side by side, the distance between entrance / exit G1 and G2 may be set to be the size of the determination area (the diameter of the semicircle). In this case, by arranging the positions of determination areas A7 and A8 to coincide with the centers of entrance / exit G1 and G2, the determination areas can be prevented from overlapping.

[0045] In this embodiment, the size of the determination area is adjusted according to the distance between the link closest to the entrance / exit and the entrance / exit, but the size of the determination area is set so that even when the distance reaches the first threshold, the size does not reach the lower limit. That is, in step S120, the size of the determination area is adjusted between a specific value and an upper limit, but the specific value is greater than the lower limit. The first threshold is a value used to determine whether or not to set the size of the determination area according to the distance between the link closest to the entrance / exit and the entrance / exit, and it is sufficient if it is set in advance.

[0046] In step S115, if it is not determined that the nearest link exists within a range of the entrance / exit location that is less than or equal to the first threshold, the control unit 20 uses the function of the determination area generation unit 21c to determine whether or not the nearest link exists within a range of the entrance / exit location that is less than or equal to the second threshold (step S135). Specifically, the control unit 20 refers to the map information 30a and obtains link data for the link connected to the entrance / exit selected in step S100. The control unit 20 also identifies the link closest to the entrance / exit based on this link data. The control unit 20 then identifies the distance between the entrance / exit location and the link closest to the entrance / exit, and if this distance is less than or equal to the second threshold, it determines that the nearest link exists within a range of the entrance / exit location that is less than or equal to the second threshold. The distance between the entrance / exit and the link may be determined by the distance of the perpendicular line drawn from the entrance / exit to the link, etc. Here, the second threshold is a value greater than the first threshold.

[0047] In step S135, if it is determined that the nearest link is within a range of the entrance / exit location that is less than or equal to the second threshold, the control unit 20 uses the function of the determination area generation unit 21c to set the size of the determination area to a predetermined size and set the center of the determination area to the entrance / exit location (step S140). That is, if the distance between the entrance / exit location and the link closest to the entrance / exit is greater than the first threshold and less than or equal to the second threshold, the size of the determination area is set to a predetermined size.

[0048] As shown in Figure 7, when the distance L2 between the entrance / exit position and the link closest to the entrance / exit increases, the likelihood that the vehicle is traveling near the entrance / exit increases when transitioning from a map-matched state to a map-unmatched state. Therefore, when the distance between the entrance / exit position and the link closest to the entrance / exit becomes somewhat large, the likelihood that the travel trajectory O1 formed by the position jump when transitioning from a map-matched state to a map-unmatched state will overlap with the entrance / exit increases. Accordingly, in this embodiment, when it is expected that the travel trajectory O1 will overlap with the entrance / exit, the size of the determination area is fixed to a predetermined size. However, compared to when the entrance / exit is on a link, there may be a positional shift due to autonomous navigation, so it is preferable that the predetermined size be greater than the lower limit value in step S110.

[0049] Therefore, in this embodiment, the control unit 20 sets the size of the determination area to a predetermined size greater than the lower limit value. Furthermore, the control unit 20 sets the position of the determination area so that the center of the determination area (the center of the circle when the determination area is considered to be semicircular) is at the position of the entrance / exit. Note that the predetermined size in step S140 may be the same as the minimum size of the determination area set in step S120 (the size of the determination area when the distance is greatest).

[0050] In step S135, if it is not determined that the nearest link exists within a range of the second threshold or less from the entrance / exit location, or if step S120 is executed, the control unit 20 makes a determination based on the nearest unconnected link, which is the nearest link among the links not connected to the entrance / exit. To this end, the control unit 20 uses the function of the determination area generation unit 21c to determine whether or not an unconnected nearest link exists within a range of the third threshold or less from the entrance / exit location (step S125).

[0051] Specifically, the control unit 20 refers to the map information 30a and obtains link data for links that are not connected to the entrance / exit selected in step S100. Based on this link data, the control unit 20 identifies the link closest to the entrance / exit as the nearest unconnected link. The control unit 20 then determines the distance between the location of the entrance / exit and the link closest to it, and if this distance is less than or equal to the third threshold, it determines that there is a nearest unconnected link that is less than or equal to the third threshold from the location of the entrance / exit. The distance between the entrance / exit and the link may be determined by the distance of a perpendicular line drawn from the entrance / exit to the link, etc.

[0052] In step S125, if it is not determined that there is an unconnected nearest link within a range of the third threshold from the entrance / exit location, the control unit 20 skips step S125. On the other hand, if it is determined in step S125 that there is an unconnected nearest link within a range of the third threshold from the entrance / exit location, the control unit 20 uses the function of the determination area generation unit 21c to set the size of the determination area according to the intersection angle between the unconnected nearest link and the vehicle's travel trajectory when passing through the entrance / exit, and sets the center of the determination area at the entrance / exit location (step S130).

[0053] Specifically, the control unit 20 refers to the travel history 30b and obtains the travel trajectory of the vehicle that passed through the entrance / exit selected in step S100. In this embodiment, the travel trajectory is represented by a straight line that best matches a trajectory within a predetermined range. If multiple travel trajectories of vehicles that have passed through the entrance / exit are recorded, the travel trajectory is obtained by statistically analyzing these travel trajectories.

[0054] Furthermore, the control unit 20 obtains the intersection angle (acute angle) between the nearest unconnected link and the travel trajectory, and sets the size of the determination area so that the closer the magnitude of the intersection angle is to 0°, that is, the closer the nearest unconnected link and the travel trajectory are to parallel, the larger the size of the determination area becomes.

[0055] Figure 8 shows an example where facility F has an entrance / exit G3 connected to link Ln1. In this example, link Ln2, which is adjacent to facility F, is not connected to entrance / exit G3. Therefore, in this example, vehicles can enter and exit entrance / exit G3 from link Ln1, but they cannot enter or exit entrance / exit G3 from link Ln2. In this example, link Ln2 is the nearest link that is not connected to entrance / exit G3, and is therefore the nearest unconnected link.

[0056] In this example, the direction of the vehicle's trajectory as it passes through entrance / exit G3 is close to the direction of link Ln2, making it prone to mismatching during map matching. Specifically, the dashed line shows the vehicle's trajectory when it turns right from link Ln3, passes through link Ln1, and immediately turns left to enter facility F from entrance / exit G3. Generally, map matching processes attempt to identify the vehicle's position as a position on a link as much as possible. Therefore, in the trajectory shown in Figure 8, even if the vehicle turns right from link Ln3 and travels through link Ln1, it is not immediately matched to link Ln1. Instead, when the vehicle turns left towards entrance / exit G3, it is prone to being matched to link Ln2 based on its trajectory, resulting in a mismatch.

[0057] When such mismatching occurs, the vehicle's position may remain mismatched as being on link Ln2 for the duration that the direction of the travel trajectory is approximately parallel to link Ln2. Then, as the difference between the direction of the travel trajectory and the direction of link Ln2 increases, or as the distance increases, the matching is lost, and the system switches to autonomous navigation. For this reason, in the example shown in Figure 8, map matching is achieved before position Pout, but after position Pout, map matching is lost, resulting in a position jump before and after position Pout. This misjudgment due to the position jump is more likely to occur when the nearest unconnected link and the entry / exit point are close together, and when the vehicle's travel trajectory passing through the nearest unconnected link and the entry / exit point is nearly parallel.

[0058] Therefore, in this embodiment, the control unit 20 determines whether or not the erroneous judgment shown in Figure 8 is likely to occur based on the third threshold. For this reason, the third threshold can be any value that has been predetermined as the distance at which the erroneous judgment is likely to occur.

[0059] Furthermore, the control unit 20 increases the size of the determination area as the direction of the vehicle's trajectory passing through the entrance / exit becomes closer to parallel with the nearest unconnected link. The direction of the trajectory may be determined by various methods, but in this embodiment, the control unit 20 acquires the straight line closest to the trajectory within a predetermined range including the entrance / exit as the direction of the trajectory. In Figure 8, the direction of the trajectory is shown by the solid straight line Lo. Of course, this configuration is just one example, and the direction of the tangent to the trajectory at a specific location or the statistical value of the tangent directions at multiple points may also be used as the direction of the trajectory.

[0060] The control unit 20 then obtains the acute angle among the intersection angles between the nearest unconnected link and the direction of the travel trajectory, and sets the size of the determination area such that the smaller the angle, the larger the size of the determination area. Such a configuration can be realized by various configurations, and in this embodiment, the size of the determination area (the diameter of the semicircle) is predetermined to correspond to the intersection angle. Since the determination area is set within the facility, the determination area is determination area A in Figure 8. 11 As shown, the size is set so as not to include the area outside facility F. With the above configuration, the possibility of misjudgment occurring when transitioning from a map-matched state to a non-map-matched state can be reduced.

[0061] If any of steps S110, S130, or S140 is executed, or if in step S125 it is not determined that there is an unconnected nearest link within a range of the third threshold or less from the location of the entrance / exit, the control unit 20 determines whether processing has been completed for all of the entrance / exit targets for which a determination area should be set (step S145). If in step S145 it is not determined that processing has been completed for all of the entrance / exit targets for which a determination area should be set, the control unit 20 repeats the processing from step S100 onwards. If in step S145 processing has been completed for all of the entrance / exit targets for which a determination area should be set, the control unit 20 terminates the map information generation process. After this, the updated map information 30a is transmitted to the vehicle at any time and stored on a storage medium (not shown), and thereafter, the navigation processing of the control unit 130 can use the updated map information 30a to provide guidance regarding entrance / exits.

[0062] (3) Other embodiments: The above embodiments are merely examples for carrying out the present invention, and various other embodiments can be adopted. For example, at least a portion of each part constituting the map information generation system 10 may be divided into multiple devices or systems. Also, at least a portion of the driving history acquisition unit 21a, map information acquisition unit 21b, and determination area generation unit 21c constituting the map information generation system 10 may be divided into multiple devices. Furthermore, some configurations of the above embodiments may be omitted, and the order of processing may be changed or omitted. For example, steps S125 and S130 may be executed after steps S110 and S140. Also, steps S135 and S140 may be omitted. Furthermore, the size of the reference size of the determination area may be predetermined, and in steps S110 and S140, the size of the determination area may be made smaller than the reference size, and in steps S120 and S130, the size of the determination area may be made larger than the reference size.

[0063] The map information acquisition unit only needs to be able to acquire map information that includes information indicating links corresponding to road sections and information indicating the locations of entrances and exits of facilities located around the road sections. In other words, the map information acquisition unit only needs to be able to acquire map information that identifies the positional relationship between links and entrances / exits. The map information only needs to include at least information indicating links and information indicating the locations of facility entrances / exits, but may also include other information. The information indicating links only needs to be information that can virtually reproduce the road network, and includes at least information indicating the location of links, but may also include shape interpolation point information, etc. The facilities only need to be facilities with vehicle entrances and exits, and are not limited in genre, etc. Entrances and exits may be for entry only and exit only. In this case, there is at least one entrance-only entrance / exit and at least one exit-only entrance / exit.

[0064] The determination area generation unit should be able to set the size and position of a determination area for determining whether or not a vehicle has passed through an entrance / exit, based on the positional relationship between the link closest to the entrance / exit and the entrance / exit, and add it to the map information in association with the entrance / exit. In other words, rules for setting the size and position of the determination area are predetermined according to the positional relationship between the link closest to the entrance / exit and the entrance / exit, and the determination area generation unit should set the size and position of the determination area according to these rules. The positional relationship can be defined in various ways, such as the distance between the link and the entrance / exit, or the relationship between the typical trajectory of a vehicle passing through the entrance / exit and the direction of the link.

[0065] The size and position of the determination area may be variable. The shape of the determination area is not limited to a semicircular shape as in the embodiment described above. For example, it may be a shape obtained by cutting a polygon, a rectangle, etc. When the size and position of the determination area are set and an update is performed in which information indicating the determination area is added to the map information, the update is reflected in terminals (navigation systems, etc.) that provide various services using the map information.

[0066] Furthermore, the present invention is also applicable as a program or method. Moreover, such systems, programs, and methods may be implemented as standalone devices or using shared components, encompassing various embodiments. For example, it is possible to provide methods and programs implemented using such systems. Furthermore, the components can be modified as appropriate, such as being partly software and partly hardware. The invention also functions as a storage medium for programs that control devices. Of course, the storage medium for such software may be a magnetic storage medium, a semiconductor memory, or any storage medium developed in the future can be considered in exactly the same way. [Explanation of Symbols]

[0067] 10...Map information generation system, 20...Control unit, 21...Map information generation program, 21a...Driving history acquisition unit, 21b...Map information acquisition unit, 21c...Determination area generation unit, 30...Storage medium, 30a...Map information, 30b...Driving history, 40...Communication unit, 100...Vehicle, 110...Communication unit, 120...Positioning unit, 130...Control unit, 140...Map information, 150...Driving history

Claims

1. A map information acquisition unit acquires map information including information indicating links corresponding to road sections and information indicating the locations of entrances and exits of facilities located around the road sections. A determination area generation unit sets the size and position of a determination area for determining whether or not the entry / exit has been passed, based on the positional relationship between the link closest to the entry / exit and the entry / exit, and adds it to the map information in association with the entry / exit. A map information generation system equipped with the following features.

2. The determination region generation unit, The size of the determination area is set to be less than or equal to a predetermined upper limit, and the closer the distance between the link closest to the entrance / exit and the entrance / exit, the larger the size of the determination area. The map information generation system according to claim 1.

3. The determination region generation unit, The size of the determination area is set to be less than or equal to a predetermined upper limit, and the size of the determination area is increased as the link closest to the entrance / exit among the links not connected to the entrance / exit is nearly parallel to the trajectory of the vehicle as it passes through the entrance / exit. The map information generation system according to claim 1.

4. The determination region generation unit, If the aforementioned entrance / exit is located on the link, the size of the determination area is made smaller than when the entrance / exit is not located on the link. A map information generation system according to claim 2 or claim 3.

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