JP2012141139A - Correction position specification device, correction position specification method and correction position specific program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a correction position specification device enabling earlier identification of vehicle approach outside a road registered in map information.SOLUTION: In the correction position specification device, there are executed: obtaining a trajectory in time sequence of a detected position indicating a position of a vehicle based on an output signal from a detector installed in the vehicle as a detected position trajectory; obtaining map information indicating a position and a form of a road; searching a travel road which is the road existing within a predetermined search area and having a form similar to the trajectory of the detected position using the map information based on the position of the vehicle; identifies a position on the travel road based on the trajectory of the detected position as a corrected position of the vehicle if the travel road is searched; and, if reliability of the trajectory of the detected position is higher than a predetermined reference reliability, setting the search area smaller than that of a case where the reliability is equal to or lower than the reference reliability.

Description

  The present invention relates to a technique for specifying a correction position of a vehicle by map matching processing.

  A navigation device has been proposed that determines whether a vehicle has entered another road or a parking lot from an intersection when there is an intersection and a parking lot along the road on which the vehicle travels (Patent Document). 1, see). The navigation device of Patent Literature 1 determines whether or not a parking lot exists within a certain range from the position of the vehicle when the vehicle decelerates below a certain speed and further turns. And if there is a parking lot within a certain range from the position of the vehicle, it is assumed that the vehicle has entered the parking lot instead of entering the other road from the intersection, and map matching to the other road is canceled To do. Thereby, it can identify early that it approached to a parking lot and can stop erroneous map matching to other roads at an early stage.

JP-A-10-197268

However, the technique of Patent Document 1 is effective when it can be specified by map information that a parking lot exists along the road, but it cannot be specified that a parking lot exists along the road. However, there was a problem that it was not possible to specify early that the vehicle entered the parking lot or the like.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for quickly identifying that a vehicle has entered outside a road registered in map information.

  In order to achieve the above object, in the present invention, the detection position trajectory acquisition means acquires, as the detection position trajectory, a time-series trajectory of the detection position indicating the position of the vehicle based on the output signal of the detector provided in the vehicle. . The traveling road search means searches the map information for a traveling road that is within a predetermined search range from the position of the vehicle and has a shape similar to the shape of the detected position locus. The map information is information indicating the position and shape of the road and is acquired by the map information acquisition means. The correction position specifying means specifies a correction position indicating the position of the vehicle by correcting the detection position to a position on the traveling road. Then, the search range setting means makes the search range smaller when the reliability of the detected position trajectory is higher than the predetermined reference reliability than when the reliability is equal to or lower than the reference reliability.

  When the reliability of the detected position trajectory is higher than the reference reliability, the search range setting means reduces the search range, thereby reducing the number of travel road candidates that the travel road search means searches in the map information. Can do. By reducing the number of traveling road candidates to be searched using map information, it is possible to increase the possibility that the shapes of all the candidate roads will not resemble the shape of the detected position trajectory. Therefore, it is possible to shorten the time required until there is no candidate road having a shape similar to the shape of the detected position locus that changes every moment. In other words, it is possible to quickly identify that the traveling road cannot be searched, the vehicle has not entered any of the roads registered in the map information, and the vehicle has entered outside the road registered in the map information. By the way, the search range is a range from the position of the vehicle, and may be a range from the detection position or a range from the correction position. Here, when the reliability of the detection position trajectory is low, the accuracy of specifying the detection position and the correction position is also low. Therefore, by reducing the search range from the vehicle position, the road on which the vehicle actually travels travels. There may be a negative effect that the road is not searched. On the other hand, the search range setting means does not reduce the search range when the reliability of the detected position trajectory is equal to or lower than a predetermined reference reliability, so that the vehicle actually travels when the reliability of the detected position trajectory is low. It is possible to prevent the road being searched from being searched as a traveling road.

  The detection position trajectory acquisition means only needs to acquire a detection position trajectory that is a time-series trajectory of the detection position based on an output signal of a detector provided in the vehicle, and an output signal from a GPS receiver as a detector and a vehicle speed sensor. A detection position trajectory that is a trajectory of a detection position based on the detection position may be acquired, or a detection position trajectory that is a trajectory of the detection position based only on an output signal of a GPS receiver as a detector may be acquired. Moreover, you may acquire the detection position locus | trajectory which is a locus | trajectory of the detection position obtained combining the output signal of the GPS receiver as a detector, a vehicle speed sensor, and a gyro sensor. The correction position trajectory is a trajectory having a shape reflecting the shape of the traveling road indicated by the map information, whereas the correction position trajectory is a detection position not corrected based on the map information.

  The travel road search means searches for roads that exist within a predetermined search range from the position of the vehicle as travel road candidates, and searches for roads having a shape similar to the shape of the detected position trajectory among these candidates as travel roads. For example, the traveling road search means may search the road having the highest similarity to the detected position trajectory among the traveling road candidates as the traveling road, and further, the similarity to the detected position trajectory among the candidates for the traveling road. A road having the highest value and higher than a predetermined threshold may be searched as a traveling road. The search range is a range determined based on the correction position, and may be a range corresponding to a predetermined figure with the correction position as the center of gravity or the like, or a range along a travel road searched in the past. Also good. Furthermore, the search range may be determined based on the number of links corresponding to road sections that need to travel before reaching the correction position.

  The correction position specifying means only needs to specify the correction position indicating the position of the vehicle by correcting the detection position to a position on the traveling road, and the position closest to the detection position among the positions on the traveling road is the correction position. May be specified. The correction position specifying means specifies the displacement of the vehicle from the past predetermined time to the present based on the detected position locus, and the position obtained by adding the displacement to the correction position at the past predetermined time is the current correction position. May be specified.

  The search range setting means only needs to make the search range smaller when the reliability of the detected position locus is higher than the reference reliability than when the reliability is equal to or lower than the reference reliability, and at least the reliability is higher than the reference reliability. The size of the search range may be switched between the case where it is high and the case where the reliability is below the reference reliability. Further, the search range setting means may reduce the search range stepwise or continuously depending on the reliability of the detection position trajectory.

  The search range setting means can specify the reliability of the detected position locus by various methods. For example, the reliability of the detected position trajectory may be specified based on the operation status of the detector for obtaining the detected position trajectory, or the shape of the detected position trajectory is highly realistic as the shape of the traveling trajectory of the vehicle. The reliability may be specified based on whether or not there is. Furthermore, the reliability of the detection position trajectory may be specified based on a comparison between the correction position trajectory that is a time-series trajectory of the correction position and the detection position trajectory. That is, it is determined whether the similarity between the corrected position locus and the detected position locus is higher than the reference similarity. When the similarity is higher than the reference similarity, the reliability of the detected position locus is higher than the reference reliability. May be high. Since the correction position trajectory is a correction position trajectory on the traveling road, it is a highly realistic trajectory as a vehicle travel trajectory, and if the shape is similar to the correction position trajectory, the reliability of the detection position trajectory is high. it can.

  Further, the search range setting means may specify the similarity between the corrected position locus and the detected position locus based on the distance between the corrected position locus and the detected position locus. That is, the search range setting means determines that the similarity between the corrected position locus and the detected position locus is higher than the reference similarity when the distance between the corrected position locus and the detected position locus is shorter than a predetermined reference distance. May be. It can be said that the shorter the distance between the corrected position locus and the detected position locus, the closer the shape of the detected position locus is to the shape of the actual road and the higher the reliability of the detected position locus. For example, the distance between the corrected position locus and the detected position locus can be grasped based on the maximum value, the minimum value, the average value, or the like of the distance between the corrected position locus and the detected position locus. Further, the search range setting means may extract a feature point from the shape of the corrected position locus and the shape of the detected position locus, and specify the similarity between the corrected position locus and the detected position locus by comparing the feature points. . Further, the search range setting means may specify the similarity based on the azimuth difference between the straight line portion included in the shape of the corrected position locus and the straight line portion included in the detected position locus.

  Further, the search range setting means includes an attention detection position locus that is a portion corresponding to a predetermined attention period that continues to the present among the detection position locus, and an attention correction position locus that is a portion corresponding to the attention period of the correction position locus. It may be determined whether the similarity to is higher than the reference similarity. By limiting the portion for determining the degree of similarity to the portion corresponding to the attention period, the processing load for determining the reliability can be reduced. Further, since the attention period is a period including the present, the latest reliability of the detected position locus can be specified. Note that the attention period may be determined by the length of the period, or may be determined by the distance the vehicle travels during the attention period.

  Further, the search range setting means, when at least one of the shape of the attention detection position locus and the shape of the attention correction position locus does not include N or more (natural numbers) bending points, the attention detection position locus and the attention correction position. The determination of the similarity to the locus may not be performed. The smaller the number of inflection points in the shape of the attention detection position locus and the shape of the attention correction position locus, the less the features of the shape of the attention detection position locus and the shape of the attention correction position locus. Cannot be identified with high accuracy. In such a case, the determination of the similarity between the detected position locus and the corrected position locus is not performed, thereby reducing the processing load and setting the search range based on the similarity of the shape with low accuracy. Can be prevented. The inflection point may be a point where the angle formed by the two straight lines constituting the trajectory shape is a predetermined angle or more, or may be a point where the radius of curvature of the trajectory shape is a predetermined value or less. .

  Furthermore, the method of adjusting the search range for searching for a traveling road as in the present invention can also be applied as a program or method. In addition, the above-described device, program, and method may be realized as a single device or may be realized by using components shared with each part of the vehicle, and include various aspects. It is a waste. For example, it is possible to provide a navigation device, a method, and a program that include the above devices. Further, some changes may be made as appropriate, such as a part of software and a part of hardware. Furthermore, the invention is also established as a recording medium for a program for controlling the apparatus. Of course, the software recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future.

It is a block diagram of a correction position specifying device. (2A) and (2B) are schematic diagrams showing map matching processing. (3A) is a flowchart of search candidate setting processing, and (3B) is a flowchart of execution feasibility determination processing. (4A) is a flowchart of shape similarity determination processing, (4B) is a flowchart of comparison interval extraction processing, and (4C) is a schematic diagram of comparison interval extraction processing. It is a flowchart of a shape comparison process. (6A) and (6B) are diagrams showing an attention correction position locus and an attention detection position locus. (7A) is a flowchart of search range setting processing, and (7B) is a flowchart of search candidate extraction processing.

Here, embodiments of the present invention will be described in the following order.
(1) Configuration of the correction position specifying device:
(2) Correction position specifying process:
(2-1) Map matching process:
(2-2) Search candidate setting process:
(2-2-1) Executability determination processing:
(2-2-2) Shape similarity determination process:
(2-2-1) Comparison section extraction process:
(2-2-2-2) Shape comparison process:
(2-2-3) Search range setting process:
(2-2-4) Search candidate extraction process:
(3) Other embodiments:

(1) Configuration of the correction position specifying device:
FIG. 1 is a block diagram showing a configuration of a correction position specifying device 10 according to the present invention. The correction position specifying device 10 includes a control unit 20 and a recording medium 30. The control unit 20 includes a CPU, a RAM, a ROM, and the like, and executes various programs stored in the recording medium 30 and the ROM. The recording medium 30 records map information 30a. The map information 30a includes node data indicating the positions of nodes set on the road on which the vehicle is traveling, shape interpolation point data for specifying the shape of the road between the nodes, and link data indicating the connection between the nodes. And feature data indicating the position and type of features existing on the road and its surroundings.

  The correction position specifying device 10 is mounted on a vehicle. A vehicle on which the correction position specifying device 10 is mounted includes a user I / F unit 40, a vehicle speed sensor 41, a gyro sensor 42, and a GPS receiving unit 43. The vehicle speed sensor 41, the gyro sensor 42, and the GPS receiver 43 constitute a detector. In the present embodiment, the user I / F unit 40 includes a touch panel that serves as both a receiving unit that receives an operation from the user and a display unit that displays a map. The vehicle speed sensor 41 outputs an output signal corresponding to the rotational speed of the wheels included in the vehicle to the control unit 20 of the correction position specifying device 10. The gyro sensor 42 outputs an output signal corresponding to the angular velocity acting on the vehicle to the control unit 20 of the correction position specifying device 10. The GPS receiver 43 receives radio waves from GPS satellites and outputs an output signal for specifying the position of the vehicle to the control unit 20 of the corrected position specifying device 10.

  The control unit 20 executes the navigation program 21 as one of the various programs described above. The navigation program 21 includes a detected position trajectory acquisition unit 21a, a map information acquisition unit 21b, a traveling road search unit 21c, a correction position specification unit 21d, and a search range setting unit 21e.

  The detection position trajectory acquisition unit 21a is a module that causes the control unit 20 to execute a function of acquiring, as the detection position trajectory, a time-series trajectory of the detection position indicating the position of the vehicle based on the output signal of the detector provided in the vehicle. . That is, the control unit 20 acquires the output signals of the vehicle speed sensor 41, the gyro sensor 42, and the GPS receiving unit 43 by the function of the detection position locus acquisition unit 21a. Based on the output signal of the vehicle speed sensor 41 and the output signal of the gyro sensor 42, the control unit 20 uses the function of the detection position locus acquisition unit 21a to generate a current value every time the vehicle travels a predetermined unit distance (1.2 m). The position of the vehicle is specified as the detection position. Based on the output signal from the gyro sensor 42, the control unit 20 acquires, as a relative direction, the amount of change in the direction of the vehicle that has changed during the unit distance traveled based on the output signal of the gyro sensor 42. Whether or not the vehicle has traveled a unit distance can be determined based on the time integral value of the vehicle speed based on the output signal of the vehicle speed sensor 41. With the function of the detection position trajectory acquisition unit 21a, the control unit 20 acquires the detection direction which is the current direction of the vehicle by accumulating the relative direction every time the vehicle travels a unit distance. With the function of the detection position trajectory acquisition unit 21a, the control unit 20 acquires, as the detection position in the current cycle, the position moved by the unit distance from the detection position specified in the previous cycle to the detection direction specified in the current cycle. To do.

  Note that the control unit 20 specifies the initial detection position and the initial detection direction based on the output signal of the GPS receiving unit 43 as a detector, for example, by the function of the detection position locus acquisition unit 21a. By sequentially accumulating the relative azimuth with respect to the initial detection azimuth, the detection azimuth as the absolute azimuth can be updated. Further, the detection position as the absolute position can be updated by repeating the process of moving the unit distance to the detection direction with the initial detection position as a reference. With the function of the detection position trajectory acquisition unit 21a, the control unit 20 acquires a time-series detection position trajectory as a detection position trajectory. The control unit 20 may appropriately correct the detection position trajectory so as to match the trajectory of the vehicle position based on the output signal of the GPS receiving unit 43 by the function of the detection position trajectory acquisition unit 21a. With the function of the detection position locus acquisition unit 21a, the control unit 20 acquires a time-series locus of the detection positions acquired as described above as a detection position locus.

  The map information acquisition unit 21b is a module that causes the control unit 20 to execute a function of acquiring map information 30a indicating the position and shape of the road. That is, the control unit 20 reads the map information 30a from the recording medium 30 by the function of the map information acquisition unit 21b. The traveling road search unit 21c has a function of searching the map information 30a for a traveling road that is within a predetermined search range from the position of the vehicle and has a shape similar to the shape of the detected position locus. 20 is a module to be executed. That is, by the function of the traveling road search unit 21c, the control unit 20 acquires a candidate for the traveling road from the map information 30a for a road existing within the search range from the correction position indicating the position of the vehicle. A road having a shape with the highest similarity to the shape of the detected position locus is searched as a traveling road.

  The correction position specifying unit 21d is a module that causes the control unit 20 to execute a function of specifying the correction position indicating the position of the vehicle by correcting the detected position to a position on the driving road when the driving road can be searched. . That is, when the traveling road can be searched by the function of the corrected position specifying unit 21d, the control unit 20 specifies the corrected position of the vehicle from the position on the traveling road based on the detected position locus. For example, the control unit 20 of the correction position specifying unit 21d specifies the closest position on the traveling road from the current detection position based on the detection position locus as the correction position. In the present embodiment, since the detection position is specified every time the vehicle travels by a unit distance (1.2 m), the distance between the correction positions that are specified in a continuous cycle also substantially matches the unit distance. On the other hand, when the travel road cannot be searched, the control unit 20 determines (off-road determination) that the vehicle travels a position outside the road registered in the map information 30a by the function of the correction position specifying unit 21d.

  As described above, when the functions of the modules 21a to 21d described above allow the control unit 20 to search for a traveling road on which the vehicle is traveling based on the map information 30a and the detected position locus, the traveling road can be retrieved. First, a map matching process for specifying a correction position on the traveling road based on the detected position locus is executed. However, if the travel road cannot be searched as an exception, the control unit 20 specifies that the vehicle is traveling at a position that is not on the road registered in the map information 30a. The condition for searching for a road is that one road that is within a predetermined search range from the position of the vehicle and has a shape similar to the shape of the detected position locus is registered in the map information 30a. It is that you are. Therefore, the smaller the search range is, the more the number of driving road candidates can be reduced, the required time until it can be determined that the driving road cannot be searched can be shortened, and the position outside the road registered in the map information 30a can be Can be identified at an early stage. The search range setting unit 21e is a module for setting a search range having the above characteristics, that is, a required period until it is specified that the vehicle is traveling in a position outside the road registered in the map information 30a. It is positioned as a module for adjustment.

  The search range setting unit 21e executes a function for reducing the search range in the control unit 20 when the reliability of the detected position locus is higher than a predetermined reference reliability than when the reliability is equal to or lower than the reference reliability. This module That is, by the function of the search range setting unit 21e, the control unit 20 determines whether or not the reliability of the detected position trajectory is higher than a predetermined reference reliability, and the reliability of the detected position trajectory is higher than the predetermined reference reliability. If it is too high, the search range is reduced.

  By the function of the search range setting unit 21e, the control unit 20 determines whether or not the reliability of the detected position locus is higher than a predetermined reference reliability by the following specific method. That is, the function of the search range setting unit 21e allows the control unit 20 to detect the detection position when the similarity between the correction position trajectory that is a time-series trajectory of the correction position and the detection position trajectory is higher than a predetermined reference similarity. Assume that the reliability of the trajectory is higher than the reference reliability. More specifically, by the function of the search range setting unit 21e, the control unit 20 causes the attention correction position locus that is a portion corresponding to a predetermined attention period that continues to the present among the correction position locus and the attention period of the detection position locus. Assume that the similarity between the corrected position trajectory and the detected position trajectory is higher than the reference similarity when the distance from the target detected position trajectory that is a portion corresponding to is shorter than a predetermined reference distance. In the present embodiment, a locus from a current detection position to a detection position that is back by a predetermined distance is set as a target detection position locus. In this case, the period of interest starts from the time when a detection position that is a predetermined distance away from the current detection position is detected, and the current period is the attention period. In addition, the function of the search range setting unit 21e allows the control unit 20 to detect the attention correction position locus part and the attention detection position locus when the attention detection position locus does not include N (N = 1) or more bending points. The search range is set without determining whether or not the similarity is higher than the reference similarity. That is, when the attention detection position trajectory indicates that the vehicle has traveled straight ahead for a predetermined distance or longer continuously, the process of analyzing the similarity between the attention correction position trajectory part and the attention detection position trajectory is omitted. .

  In the configuration of the present embodiment described above, when the reliability of the detected position trajectory is higher than the reference reliability, the control unit 20 reduces the search range so that the control unit 20 searches for the map information 30a. The number of road candidates can be reduced. By reducing the number of traveling road candidates to be searched in the map information 30a, it is possible to increase the possibility that the shapes of all the candidate roads are not similar to the shape of the detected position trajectory. Therefore, it is possible to shorten the time required until there is no candidate road having a shape similar to the shape of the detected position locus that changes every moment. That is, it becomes possible to search for a traveling road, and it is possible to identify early that a vehicle has entered the road registered in the map information 30a without entering the road registered in the map information 30a. By the way, when the reliability of the detection position trajectory is low, the accuracy of specifying the correction position is also low. Therefore, by reducing the search range from the correction position, the road on which the vehicle actually travels is not searched as a travel road. Bad effects can also occur. On the other hand, the control unit 20 does not reduce the search range when the reliability of the detection position trajectory is equal to or lower than the predetermined reference reliability, so that the vehicle actually travels when the reliability of the detection position trajectory is low. It can be prevented that the existing road is not searched as a traveling road.

  The control unit 20 of the present embodiment specifies the reliability based on whether or not the detected position trajectory is highly realistic as a vehicle travel trajectory. That is, the control unit 20 determines whether or not the similarity between the corrected position locus and the detected position locus is higher than the reference similarity, and when the similarity is higher than the reference similarity, the reliability of the detected position locus is determined. Is higher than the standard reliability. This is because the correction position trajectory is a trajectory of the correction position on the traveling road, and thus is a highly realistic trajectory as a vehicle travel trajectory. If the shape is similar to the correction position trajectory, the reliability of the detected position trajectory is high. .

  Furthermore, the control unit 20 determines that the similarity is higher than the reference similarity when the distance between the correction position locus and the detection position locus is shorter than a predetermined reference distance. It can be said that the shorter the distance between the corrected position locus and the detected position locus, the closer the shape of the detected position locus is to the shape of the actual road and the higher the reliability of the detected position locus. More specifically, the control unit 20 detects the attention detection position locus that is a portion corresponding to a predetermined attention period that continues to the present among the detection position locus, and the attention correction that is a portion corresponding to the attention period among the correction position locus. It is determined whether the similarity with the position locus is higher than the reference similarity. By limiting the portion for determining the degree of similarity to the portion corresponding to the attention period, the processing load for determining the reliability can be reduced. Further, since the attention period is a period including the present, the latest reliability of the detected position locus can be specified.

  In addition, when the shape of the attention detection position locus or the shape of the attention correction position locus does not include N (N = 1) or more bending points, the control unit 20 calculates the attention detection position locus and the attention correction position locus. The similarity is not judged. The smaller the number of bending points in the shape of the attention detection position trajectory or the attention correction position trajectory, the fewer the features of the shape of the attention detection position trajectory or the shape of the attention correction position trajectory. Cannot be identified with high accuracy. In such a case, the determination of the similarity between the detected position locus and the corrected position locus is not performed, thereby reducing the processing load and setting the search range based on the similarity of the shape with low accuracy. Can be prevented.

(2) Correction position specifying process:
Next, the correction position specifying process executed by the control unit 20 by the function of the navigation program 21 will be described. The correction position specifying process includes a map matching process and a search candidate setting process which are executed every predetermined period. Here, map matching processing will be described first.

(2-1) Map matching process:
2A and 2B are schematic diagrams showing map matching processing. 2A and 2B show the same roads R1 to R4. As described above, the map matching process is a process that is executed for each cycle in which the vehicle travels a unit distance. The number of the current cycle is expressed as n (natural number). As shown in FIGS. 2A and 2B, the control unit 20 acquires a detection position locus S (broken line) by the function of the detection position locus acquisition unit 21a. That is, by the function of the detection position locus acquisition unit 21a, the control unit 20 specifies the detection position Q _n based on the output signals of the vehicle speed sensor 41 and the gyro sensor 42 every time the vehicle travels a unit distance, and the current detection position Q _n. The trajectory of the time-series detection positions Q _n , Q _n−1 , Q _n−2 ... (White circles) starting from is acquired as the detection position trajectory S.

Next, by the function of the traveling road search unit 21c, the control unit 20 acquires a road at least part of which belongs to the search range A (one-dot chain line frame) as a traveling road candidate, and the shape of the detected position locus S among the candidates. A road having a shape with the highest similarity to is searched as a traveling road. The search range A is set for each predetermined period by a search candidate setting process to be described later. Specifically, a range length L that defines the size of the search range A is set in the search candidate setting process. The search range A is set with reference to the correction position P _n-1 (black circle) specified in the immediately preceding cycle (n-1). In FIGS. 2A and 2B, it is assumed that the position on the traveling road (road R1) closest to the detected position Q _n-1 is specified as the corrected position P _n-1 in the immediately preceding cycle. The search range A is the travel road (road R1) of the travel road (road R1) identified in the immediately preceding cycle by the range length L from the correction position P _n-1 in which the vehicle is identified in the immediately preceding cycle. A predetermined width W along a section from a position that is reached when retreating up to a position that is reached when the vehicle travels on the traveling road (road R1) by the range length L from the correction position P _n-1 The range is (20 m). In FIG. 2A, the range length L is set to 30 m, and in FIG. 2B, the range length L is set to 10 m.

  When the control unit 20 acquires the shape of a candidate road that is at least partly included in the search range A by the function of the traveling road search unit 21c, the degree of similarity with the shape of the detected position locus S of the candidate roads is acquired. The road having the highest shape is searched as the traveling road. For example, the similarity between the shape of the detected position trajectory S and the shape of the road may be searched based on a cost in which a difference in direction and position is comprehensively reflected.

In the case of FIG. 2A, in addition to the road R1 that is the original travel road, a part of the roads R2 to R4 that are connected to the road R1 at an intersection existing ahead in the travel direction of the vehicle exists in the search range A. Thus, the roads R1 to R4 can be candidates for the traveling road. However, in the present embodiment, candidate roads are narrowed down based on the current direction of the vehicle indicated by the detected position trajectory S by a search candidate setting process (search candidate extracting process) described later, and the detected position trajectory S is A road having a direction different from the current azimuth of the vehicle by a predetermined angle or more is excluded from the candidates for the traveling road. In the case of FIG. 2A, the road R1 perpendicular to the current direction of the vehicle indicated by the detected position trajectory S is excluded from the candidates, and only the roads R2 and R3 substantially parallel to the current direction of the vehicle are narrowed down as candidates for the traveling road. Yes. Then, the function of the traveling road search unit 21c allows the control unit 20 to have the highest similarity to the shape of the detected position locus S among the narrowed candidate roads R2 and R3, that is, similarly to the shape of the detected position locus S. A road R2 indicating a shape toward the left side is searched as a traveling road. When you search for road R2 as the travel road, the control unit 20 of the function of correcting position specifying unit 21d, the correction position of the vehicle closest to the detection position Q _n on the traveling road on the basis of the detected position trajectory S (road R2) _Specify as P _n .

On the other hand, in the case of FIG. 2B, the search range A is smaller than in the case of FIG. 2A, and the roads R2 to R4 are outside the search range A. That is, no road other than the original road R1, which is the original traveling road, exists in the search range A, and the road R1 is also excluded from the candidates by narrowing down candidate roads based on the orientation of the detected position locus S. It is assumed that there is no traveling road candidate, and the control unit 20 cannot retrieve the traveling road by the function of the traveling road search unit 21c. In this case, the control unit 20 specifies that the vehicle is traveling outside the road registered in the map information 30a by the function of the traveling road search unit 21c. As described above, by setting the range length L that defines the size of the search range A to be short, the number of traveling road candidates can be reduced, so that the vehicle is outside the road registered in the map information 30a. It is possible to shorten the time required until the vehicle is identified as traveling. That is, in FIG. 2A, the vehicle further travels outside the road and the detection position trajectory S is extended to the detection position Q _{n + 1} (white triangle), and the current vehicle orientation indicated by the extended detection position trajectory S; Until the direction of the road R2 differs by a predetermined angle or more, the road R2 is searched as a traveling road, and the position on the road R2 is continuously specified as the correction position. On the other hand, if the search range A is set small as shown in FIG. 2B, it is possible to wait until the current vehicle direction indicated by the detection position trajectory S is different from the direction of the road R2 by a predetermined angle or more. It can be specified that the vehicle is traveling at a position outside the road registered in the map information 30a at an early stage. Therefore, for example, it is constructed after the creation of the map information 30a, so that it enters a parking lot that is not registered as feature data in the map information 30a or a road in which a node for entering in the map information 30a is not registered. Therefore, it is possible to prevent the position on the road R2 from being set as the correction position P _n despite the left turn at a position different from the road R2, and the correction position displayed on the map by the user I / F unit 40. It is possible to prevent the user who has visually recognized _Pn from feeling uncomfortable.

(2-2) Search candidate setting process:
FIG. 3A is a flowchart showing the flow of search candidate setting processing. In step S100, the control unit 20 determines whether or not the vehicle has traveled a predetermined unit distance by the function of the search range setting unit 21e. The search candidate setting process is a loop process that is repeatedly executed for each cycle in which the vehicle travels a unit distance. The unit distance corresponding to the cycle for executing the search candidate setting process may be the same as the unit distance (1.2 m) corresponding to the cycle for executing the map matching process, but longer than the unit distance of the map matching process. May be. When the vehicle travels a unit distance, in step S110, the control unit 20 determines whether or not a traveling road can be retrieved by the function of the traveling road search unit 21c in the map matching process that is executed in parallel. If the travel road has not been searched, the control unit 20 stands by until the next unit distance travels. When the traveling road can be searched, the control unit 20 determines whether or not to execute the shape similarity determination process of step S300 in the execution determination process of step S200.

(2-2-1) Executability determination processing:
FIG. 3B is a flowchart of execution feasibility determination processing. In step S210, the control unit 20 sets a trajectory from the detection position trajectory S to the detection position Q _{n-155 that} is a predetermined distance (186 m) backward from the current detection position Q _n as the attention detection position trajectory. It is determined whether or not N (N = 1) or more bending points are included. In the present embodiment, since the unit distance (1.2 m) detection position Q each is identified, 156 of the detection position Q _n to Q identified in time close to the current including the current detection position Q _{n n- 155} constitutes the attention detection position locus. In the present embodiment, in order to reduce the processing load, the control unit 20 uniformly extracts 156 detection positions in a cycle of 5 so that 32 detection positions Q _n-5t (t is 0 to 0) every 6 m. Attention detection position trajectory configured by an integer of 31 is acquired. The control unit 20 forms a polygonal line that connects the detection positions Q that are specified in a continuous cycle, and the vehicle is at a predetermined angle (60 degrees) based on the angle formed by the polygonal lines that are connected to each other at the detection position Q. It is determined whether or not N or more bent points that have been turned are included in the attention detection position trajectory. If it is determined in step S210 that the attention detection position locus does not include N or more bending points, the control unit 20 does not execute the shape similarity determination process in step S260. That is, the shape similarity determination process is performed assuming that the attention detection position trajectory is substantially a straight line and there is no shape feature in the attention detection position trajectory sufficient to determine the similarity between the attention detection position trajectory and the attention correction position trajectory. Do not execute.

On the other hand, if it is determined in step S210 that the attention detection position trajectory includes N or more bending points, the control unit 20 in step S220 determines a predetermined distance in which the total length of the correction position trajectory is the length of the attention detection position trajectory. It is determined whether it is (186m) or more. As described above, since the correction positions P are also identified with a unit distance (1.2 m) period, 156 correction positions P _{n to} P _n-155 (black circles shown in FIGS. 2A and 2B) have been continuously recorded so far. ) May be determined in the map matching process. If it is determined in step S220 that the total length of the correction position trajectory is not equal to or greater than the predetermined distance, the control unit 20 determines that a correction position trajectory having a length that can be compared with the attention detection position trajectory cannot be acquired. The similarity determination process is not executed.

  On the other hand, if it is determined in step S220 that the total length of the correction position trajectory is equal to or greater than the predetermined distance, in step S230, the control unit 20 determines that the vehicle is the facility data of the map information 30a based on the correction position P or the detection position Q. It is determined whether or not the user has entered a registered facility that is a registered facility (parking lot, service area, parking area, etc.). If it is determined in step S230 that the vehicle has entered the registered facility registered in the map information 30a, the control unit 20 determines that there is no need to adjust the search range A for the map matching process. In step S260, the shape similarity determination process is not executed. In this embodiment, when a vehicle has entered a registered facility registered in the map information 30a, a process specific to the attribute of the registered facility is executed instead of the map matching process. There is no real benefit of setting A.

  On the other hand, when it is not determined in step S230 that the vehicle has entered the facility registered in the map information 30a, in step S240, the control unit 20 determines that the vehicle is based on the correction position P or the detection position Q. It is determined whether or not the vehicle is traveling in an urban area registered in the map information 30a. If it is determined in step S240 that the vehicle is traveling in the urban area registered in the map information 30a, the control unit 20 determines that it is not desirable to reduce the search range A for the map matching process. In step S260, the shape similarity determination process is not executed. Mountain roads and the like other than urban areas have complicated road shapes, and the reliability of the detection position trajectory S tends to decrease. Therefore, the search range A is reduced to reduce the number of road candidates in the map matching process. Is not desirable. When it is not determined in step S240 that the vehicle is traveling in the urban area registered in the map information 30a, the control unit 20 performs a shape similarity determination process in step S250. As described above, when the shape similarity determination process is executed, the control unit 20 executes the shape similarity determination process in step S300 of FIG. 3A.

(2-2-2) Shape similarity determination process:
FIG. 4A is a flowchart of the shape similarity determination process. As shown in FIG. 4A, in the shape similarity determination process, the control unit 20 first executes a comparison section extraction process in step S310.
(2-2-1) Comparison section extraction process:
FIG. 4B is a flowchart of the comparison interval extraction process. In step S311, the control unit 20 acquires a target correction position locus. The attention correction position trajectory is also acquired as the attention correction position trajectory by the same method as the attention detection position trajectory to the correction position P _{n-155 that} is a predetermined distance (186 m) backward from the current correction position P _n . In the present embodiment, in order to reduce the processing load, the control unit 20 is configured by 32 correction positions P _n-5t every 6 m by equally extracting 156 correction positions P in a cycle of five. The attention correction position locus is acquired.

In step S312, the control unit 20 selects one of the correction positions P constituting the target correction position locus as a processing target. In the present embodiment, the correction position P is selected as a processing target in order from the current correction position P _n toward the past. The correction position P currently selected as a processing target is expressed as a correction position P _a (a = n−5t). Control unit at step S313 20 includes a bearing (dashed arrow) toward the correction position P _a current selection from the corrected position P _{a + 5} previously selected one as shown in the schematic diagram of FIG. 4C, 2 one An azimuth difference α is calculated from the azimuth (one-dot chain arrow) from the correction position Pa _{+ 10} selected before to the correction position Pa _{+ 5} selected one time ago. In step S314, the control unit 20 determines whether or not the azimuth difference α is equal to or greater than a predetermined angle (60 degrees). That is, the control unit 20 determines whether or not the vehicle is turning 60 degrees or more at the correction position P _{a + 5} selected immediately before.

When it is determined in step S314 that the azimuth difference α is smaller than the predetermined angle, the control unit 20 returns to step S312 and selects the next (one past) correction position Pa _-5 . On the other hand, when it is determined in step S314 that the azimuth difference α is equal to or larger than the predetermined angle, in step S315, the control unit 20 specifies the correction position Pa _{+ 5} selected immediately before as a bending point, The correction position P _{a + 15} selected before is specified as the end point of the existing comparison section, and the correction position P _a-5 selected one after is specified as the start point of the new comparison section. If the current correction position P _n is initially selected, steps S312 to S314 are skipped, and the current correction position P _n is set as the start point of the comparison section.

  By repeatedly executing the above processing, it is possible to form a comparison section in which the target correction position locus is divided at a bending point where the shape of the target correction position locus is bent by a predetermined angle or more. In addition, a section within a predetermined distance (1.2 × 5 × 2 = 12 m) before and after the bending point is excluded from the comparison section. Since the comparison section corresponds to a section in which the vehicle has traveled without turning 60 degrees or more, the comparison section has a shape close to a straight line. In the next step S316, the control unit 20 determines the comparison section whose end point is specified in step S315. In step S317, the control unit 20 determines whether or not the cumulative number of comparison sections determined in step S316 is a predetermined M (M = 3> N + 1). When the cumulative number of comparison sections determined in step S316 is M, the control unit 20 ends the comparison section extraction process.

On the other hand, when it is determined in step S317 that the cumulative number of comparison sections determined in step S316 is less than M, the control unit 20 selects the correction position P of the correction position trajectory constituting the target correction position locus in step S318. It is determined whether or not the last correction position P _n-155 has been selected. When the last correction position P _n-155 is not selected in the selection order, the control unit 20 returns to Step S312 and selects the next (one past) correction position P. By repeating the above process, the process of extracting the comparison section from the target correction position trajectory is repeated until the last correction position P _n-155 is selected, except when M comparison sections have been extracted. Can continue. When the last correction position P _n-155 is selected, in step S315, the control unit 20 sets the last correction position P _n-155 as the end point of the comparison section regardless of the results of steps S312 to S314, and step S316. Confirm the comparison section. On the other hand, when the control unit 20 determines in step S316 that a sufficient number (M) of comparison sections to be used for comparison with the shape of the target detection position trajectory has been confirmed, the selection order is the last (most) The comparison section extraction process is terminated without repeating the process until the past correction position P _n-155 is selected as the process target. Thereby, the processing load can be reduced. As described above, when the comparison section extraction process ends, the control unit 20 returns to the shape similarity determination process of FIG. 4A and executes step S320.

  In step S320 in FIG. 4A, the control unit 20 determines whether or not (N + 1) or more comparison sections have been determined. Since N = 1 in the present embodiment, the control unit 20 determines whether or not two or more comparison sections have been confirmed. When (N + 1) or more comparison sections cannot be determined, that is, when N or more inflection points cannot be identified, the shape comparison process in step S330 is not executed. That is, it is assumed that the shape comparison process is not executed on the assumption that a sufficient number of comparison sections for use in comparison of the attention detection position trajectories cannot be extracted. On the other hand, when it is determined in step S320 that more than (N + 1) comparison sections have been determined, the control unit 20 performs shape comparison processing in step S330.

(2-2-2-2) Shape comparison process:
FIG. 5 is a flowchart of the shape comparison process. First, in step S331, the control unit 20 selects a comparison section to be processed. Here, the comparison section is selected in the order from the current position. 6A and 6B are diagrams showing the attention correction position locus X (solid line) and the attention detection position locus Y (broken line). Here, in the shape comparison process, the shortest distance between the correction positions P that is the shortest distance between the correction position P and the attention detection position locus Y is calculated, and the shortest distance between the correction positions P is calculated. This is a process of calculating the longest of these as the distance between the trajectories, and is configured by a loop process for sequentially switching the correction position P and the detection position Q to be processed. In FIGS. 6A and 6B, attention correction position trajectory X composed of three comparison sections C1 to C3 is shown. Note that the attention correction position trajectory X has a shape along the shape of the road (one-dot chain line) registered in the map information 30a. In step S332, the control unit 20 selects one of the correction positions P constituting the comparison section selected as the processing target as the correction position P of the processing target. Here, the correction positions P constituting the comparison section are selected in order from the closest to the current position. In step S333, the control unit 20 selects one of the detection positions Q constituting the target detection position locus Y as the detection position Q to be processed. Here, it is assumed that the detection position Q to be processed is selected in the order from the current position.

  In step S334, the control unit 20 determines that the azimuth difference between the vehicle orientation indicated by the attention detection position locus Y at the detection position Q to be processed and the vehicle orientation indicated by the attention correction position locus X at the correction position P to be processed is predetermined. It is determined whether or not the angle is 60 degrees or more. It was determined that the azimuth difference between the vehicle orientation indicated by the attention detection position locus Y at the processing target detection position Q and the vehicle orientation indicated by the attention correction position locus X at the processing target correction position P is smaller than a predetermined angle. In this case, in step S335, the control unit 20 calculates an inter-position distance that is a distance between the correction position P to be processed and the detection position Q to be processed. In step S336, the control unit 20 determines the recording medium according to the position distance calculated in step S335 only when the position distance calculated in step S335 is shorter than the shortest position distance held in the recording medium 30. The distance between the shortest positions recorded in 30 is overwritten. On the other hand, if the azimuth difference between the azimuth of the vehicle indicated by the attention detection position locus Y at the processing target detection position and the azimuth of the vehicle indicated by the attention correction position locus X at the processing target correction position is equal to or greater than a predetermined angle, the process proceeds to step S334. If determined, the control unit 20 skips steps S335 to S336 and executes step S337.

In step S337, the control unit 20 determines whether or not the detection position Q _n-155 having the last (most past) selection order is selected from the detection positions Q constituting the target detection position locus Y, and the selection order is the last. If the detection position Q _n-155 is not selected, the next detection position Q is selected as a processing target in step S333. By repeatedly executing the above processing (steps S333 to S337), the correction position P of the processing target that constitutes the comparison sections C1 to C3 to be processed and the detection positions Q that constitute the target detection position locus Y The distance between positions can be calculated sequentially, and the shortest distance among these distances can be held in the recording medium 30 as the shortest position distance. However, the difference between the azimuth of the vehicle indicated by the attention detection position locus Y at the detection position Q to be processed and the azimuth of the vehicle indicated by the attention correction position locus X at the correction position P to be processed is equal to or greater than a predetermined angle (60 degrees). In this case, since the inter-position distance is not calculated, only the shortest inter-position distance between the detection position Q belonging to the section close to the comparison sections C1 to C3 in the target detection position locus Y and the correction position P to be processed is recorded. It is held on the medium 30. That is, a detection position Q that is the detection position Q in the section of the attention detection position locus Y that is close to the azimuth of the attention correction position locus X at the correction position P and that has the shortest distance between the correction positions P is searched. The shortest distance between the positions, which is the distance between the detection position Q and the correction position P, is held on the recording medium 30.

On the other hand, when it is determined in step S337 that the detection position Q _n-155 having the last selection order (the past) is selected from the detection positions Q constituting the target detection position locus Y in step S337, the control unit 20 determines in step S338. Only when the distance between the shortest positions held in the recording medium 30 is longer than the distance between the traces held in the recording medium 30, the distance between the traces is overwritten with the distance between the shortest positions. In step S <b> 338, the control unit 20 erases the distance between the shortest positions held on the recording medium 30. In step S339, the control unit 20 determines whether or not the correction position having the last selection order (the past) is selected among the correction positions constituting the comparison sections C1 to C3 to be processed. When it is determined in step S339 that the last correction position P in the selection order among the correction positions P configuring the processing target comparison sections C1 to C3 is not selected as the processing target, the control unit 20 returns to step S332. Then, the next correction position P constituting the comparison sections C1 to C3 to be processed is selected as a processing target.

  If it is determined in step S339 that the correction position P that is the last selected in the correction positions P constituting the processing target comparison sections C1 to C3 is selected as the processing target, in step S340, the control unit 20 determines the selection order. It is determined whether or not the last (most past) comparison section C3 is selected as a processing target. When it is determined in step S340 that the last comparison section C3 in the selection order has not been selected as a processing target, the control unit 20 returns to step S331 and selects the next comparison section C2 to C3 as a processing measure. By repeatedly executing the above processing (steps S331 to S340), each correction position P belonging to each comparison section C1 to C3 is sequentially selected as a processing target, and each correction position P and attention detection position locus Y The distance between the shortest positions, which is the shortest distance, can be calculated sequentially. Furthermore, the longest distance between the shortest positions for each correction position P can be finally held in the recording medium 30 as the distance between the trajectories. That is, the maximum value of the distance between the attention correction position trajectory X and the attention detection position trajectory Y in a section in which the attention correction position trajectory X and the attention detection position trajectory Y are close to each other can be specified as the distance between the trajectories. In steps S331 to S332, since only the correction position P belonging to the comparison section that is a predetermined distance (12 m) or more away from the inflection point is selected as the processing target, the road shape and the actual trajectory of the vehicle are greatly deviated. It is possible to prevent the distance between trajectories from being specified based on trajectories such as intersections.

  On the other hand, if it is determined in step S340 that the last comparison section C1 to C3 in the selection order has been selected as the processing target, in step S341, the control unit 20 determines that the distance between the trajectories held in the recording medium 30 is a predetermined reference. It is determined whether or not it is shorter than the distance (10 m). That is, the control unit 20 determines the distance between the trajectories, which is the maximum value of the distance between the attention correction position trajectory X and the attention detection position trajectory Y in a section in which the attention correction position trajectory X and the attention detection position trajectory Y are close to each other. It is determined whether or not the distance is shorter than the reference distance. If it is determined that the distance between the trajectories is shorter than the reference distance, in step S342, the control unit 20 determines that the similarity between the attention correction position trajectory X and the attention detection position trajectory Y is higher than a predetermined reference similarity. . In the present embodiment, the similarity between the attention correction position trajectory X and the attention detection position trajectory Y is higher than a predetermined reference similarity. The reliability of the attention correction position trajectory X is higher than the predetermined reference reliability. It is synonymous with. On the other hand, when it is determined that the distance between the trajectories is equal to or greater than the reference distance, in step S343, the control unit 20 determines that the similarity between the attention correction position trajectory X and the attention detection position trajectory Y is equal to or less than a predetermined reference similarity. judge. In the present embodiment, the similarity between the attention correction position trajectory X and the attention detection position trajectory Y being equal to or lower than a predetermined reference similarity is synonymous with the reliability of the attention correction position trajectory X being lower than the reference reliability. It is.

  In FIG. 6B, the attention detection position trajectory Y is shifted to the left side of the drawing with respect to the attention correction position trajectory X, and the distance D between trajectories is equal to or greater than the reference distance. As shown in FIG. 6B, when the inter-trajectory distance D is equal to or greater than the reference distance, the attention detection position locus Y has a shape greatly deviating from the attention correction position locus X corresponding to the shape of the road, and the attention detection position locus Y is It can be determined that the possibility of representing an actual traveling locus is low and the reliability of the attention detection position locus Y is low. When the shape similarity determination process is completed as described above, the control unit 20 returns to the search candidate setting process of FIG. 3A and executes the search range setting process of step S400.

(2-2-3) Search range setting process:
FIG. 7A is a flowchart of the search range setting process. In step S410, the control unit 20 determines whether or not the shape similarity determination process has been executed. If it is determined that the shape similarity determination process has not been executed, the control unit 20 sets the range length L of the search range A to 30 m in step S450. On the other hand, when it is determined in step S410 that the shape similarity determination process has been executed, in step S420, the control unit 20 determines whether or not the shape comparison process has been executed. If it is determined that the shape comparison process has not been executed, the control unit 20 sets the range length L of the search range A to 30 m in step S450. That is, when the shape similarity determination process and the shape comparison process are not executed, the reliability of the detection position trajectory S may be equal to or less than the reference reliability, so the range length L of the search range A is set to 30 m. To do.

  On the other hand, if it is determined in step S420 that the shape comparison process has been executed, in step S430, the control unit 20 determines that the similarity between the attention correction position locus X and the attention detection position locus Y is higher than the reference similarity. It is determined whether or not it is determined, that is, whether or not the reliability of the attention detection position locus Y is higher than the reference reliability. If it is not determined that the similarity between the attention correction position locus X and the attention detection position locus Y is higher than the reference similarity, the control unit 20 sets the range length L of the search range A to 30 m in step S450. When it is determined that the similarity between the attention correction position locus X and the attention detection position locus Y is higher than the reference similarity, the control unit 20 sets the range length L of the search range A to 10 m in step S440. When the range length L of the search range A is set as described above, the search range setting process ends, and the control unit 20 returns to the search candidate setting process of FIG. 3A and executes the search candidate extraction process of step S500.

(2-2-4) Search candidate extraction process:
FIG. 7B is a flowchart of search candidate extraction processing. In step S510, the function of the map information acquisition unit 21b causes the control unit 20 to extract, from the map information 30a, roads that belong at least in part to the search range A set in steps S440 and S450 in FIG. . In FIG. 2A, roads R1 to R4 are extracted as driving road candidates, and in FIG. 2B, only road R1 is extracted as a driving road candidate. In step S520, by the function of the map information acquisition unit 21b, the control unit 20 narrows down driving road candidates based on the direction of the vehicle indicated by the detected position locus S. That is, the control unit 20 narrows down the driving road candidates by excluding roads whose parallelism with the current direction of the vehicle indicated by the detected position trajectory S is equal to or less than a predetermined reference from the driving road candidates. In FIG. 2A, only roads R2 and R3 that are substantially parallel to the current direction of the vehicle indicated by the detection position trajectory S are narrowed down as traveling road candidates. On the other hand, in FIG. 2B, since the only candidate road R1 and the current direction of the vehicle indicated by the detected position locus S are substantially perpendicular, it is assumed that there is no candidate road. Thus, the search candidate extraction process (search range setting process) ends, and the control unit 20 returns to step S100 of the search candidate setting process of FIG. 3A and waits until the vehicle travels a unit distance next. Further, in the map matching process executed in parallel with the search range setting process, the road having the shape most similar to the shape of the detected position trajectory S travels among the travel road candidates narrowed down by the search candidate extraction process. It will be specified as a road. By periodically executing the search candidate setting process described above, it is possible to set the search range A according to the reliability of the attention detection position locus Y that changes every moment.

(3) Other embodiments:
With the function of the detection position trajectory acquisition unit 21a, the control unit 20 may acquire a detection position trajectory S that is a time-series trajectory of the detection position Q based on the output signal of the detector provided in the vehicle. You may acquire the detection position locus | trajectory S which is a locus | trajectory of the detection position Q based on the output signal of only the GPS receiver 43. FIG. Further, the search range A is a range determined with the correction position P as a reference, and may be a range corresponding to a predetermined figure with the correction position P as the center of gravity or the like. Alternatively, the search range A may be determined based on the number of links corresponding to road sections that need to travel before reaching the correction position P.

  Depending on the function of the search range setting unit 21e, the control unit 20 may decrease the search range A in two or more steps according to the reliability of the detection position trajectory S or may decrease it continuously. With the function of the search range setting unit 21e, the control unit 20 may specify the reliability of the detection position trajectory S based on the operation status of the detector for obtaining the detection position trajectory S. That is, it is not always necessary to evaluate the reliability of the detected position locus S by comparing the shape of the detected position locus S with the corrected position locus. For example, the reliability of the detected position locus S may be evaluated by comparing the shape of the detected position locus S with the shape of the road registered in the map information 30a. Further, by the function of the search range setting unit 21e, the control unit 20 extracts a feature point (bending point or the like) from the shape of the correction position locus and the shape of the detection position locus S, and compares the feature point with the correction position locus. The similarity between the shape and the shape of the detection position locus S may be specified.

  Furthermore, in the above-described embodiment, the control unit 20 uses the function of the search range setting unit 21e to cause the detected position trajectory S to correspond to the attention period, the shape of the attention detection position trajectory, and the correction position trajectory to the attention period. The degree of similarity with the shape of the attention correction position trajectory that is the corresponding part is specified. For example, the entire shape of the detection position trajectory S and the entire shape of the correction position trajectory acquired up to the present after the power is turned on. You may evaluate the reliability of the detection position locus | trajectory S based on similarity. Note that the attention period may be determined by the length of the period.

  In the embodiment, the function of the search range setting unit 21e allows the control unit 20 to detect the shape of the attention detection position trajectory and the attention correction position when N or more bending points are not included in the shape of the attention detection position trajectory. The degree of similarity with the shape of the trajectory is not determined, but the degree of similarity between the shape of the attention detection position trajectory and the shape of the attention correction position trajectory is determined regardless of whether or not a bending point is included. Also good. The bending point may be a point where the radius of curvature of the shape of the trajectory is a predetermined value or less.

DESCRIPTION OF SYMBOLS 10 ... Correction position specification apparatus, 20 ... Control part, 21 ... Navigation program, 21a ... Detection position locus | trajectory acquisition part, 21b ... Map information acquisition part, 21c ... Travel road search part, 21d ... Correction position specification part, 21e ... Search range Setting part, 30 ... Recording medium, 30a ... Map information, 40 ... User I / F part, 41 ... Vehicle speed sensor, 42 ... Gyro sensor, 43 ... GPS receiving part, A ... Search range, C1-C3 ... Comparison section, D ... distance between loci, L ... range length, P ... correction position, Q ... detection position, R1 to R4 ... road, S ... detection position locus, W ... predetermined width, X ... attention correction position locus, Y ... attention detection position locus .

Claims (7)

Map information acquisition means for acquiring map information indicating the position and shape of the road;
Detection position trajectory acquisition means for acquiring, as a detection position trajectory, a time-series trajectory of a detection position indicating the position of the vehicle based on an output signal of a detector provided in the vehicle;
Driving road search means for searching the road information, which is the road that exists within a predetermined search range from the position of the vehicle and has a shape similar to the shape of the detected position locus, with the map information;
Correction position specifying means for specifying a correction position indicating the position of the vehicle by correcting the detected position to a position on the road when the driving road can be searched;
Search range setting means for reducing the search range when the reliability of the detection position trajectory is higher than a predetermined reference reliability than when the reliability is equal to or lower than the reference reliability;
A correction position specifying device comprising: The search range setting means determines whether a similarity between a correction position trajectory that is a time-series trajectory of the correction position and the detection position trajectory is higher than a predetermined reference similarity, and the similarity is In the case where it is higher than the reference similarity, the reliability of the detection position trajectory is higher than the reference reliability,
The correction position specifying device according to claim 1. The search range setting means determines that the similarity is higher than the reference similarity when the distance between the correction position locus and the detection position locus is shorter than a predetermined reference distance.
The correction position specifying device according to claim 2. The search range setting means includes an attention detection position locus that is a portion corresponding to a predetermined attention period that continues to the present in the detection position locus, and an attention correction that is a portion corresponding to the attention period in the correction position locus. Determining whether the similarity to a position trajectory is higher than the reference similarity;
The correction position specifying device according to claim 3. Whether or not the similarity is higher than the reference similarity when N or more (natural numbers) inflection points are not included in at least one of the shape of the attention detection position locus and the shape of the attention correction position locus Set the search range without determining
The correction position specifying device according to claim 4. A map information acquisition step for acquiring map information indicating the position and shape of the road;
A detection position trajectory acquisition step of acquiring, as a detection position trajectory, a time-series trajectory of a detection position indicating the position of the vehicle based on an output signal of a detector provided in the vehicle;
A traveling road search step of searching the map information for a traveling road that is within the predetermined search range from the position of the vehicle and has the shape similar to the shape of the detected position locus;
A correction position specifying step of specifying a correction position indicating the position of the vehicle by correcting the detection position to a position on the driving road when the driving road can be searched;
When the reliability of the detection position trajectory is higher than a predetermined reference reliability, a search range setting step for making the search range smaller than when the reliability is equal to or lower than the reference reliability;
A correction position specifying method including: A map information acquisition function for acquiring map information indicating the position and shape of the road;
A detection position trajectory acquisition function for acquiring, as a detection position trajectory, a time-series trajectory of a detection position indicating the position of the vehicle based on an output signal of a detector provided in the vehicle;
A traveling road search function for searching for the traveling road, which is the road that exists within a predetermined search range from the position of the vehicle and has a shape similar to the shape of the detected position locus, with the map information;
A correction position specifying function for specifying a correction position indicating the position of the vehicle by correcting the detection position to a position on the driving road when the driving road can be searched;
A search range setting function for reducing the search range when the reliability of the detection position locus is higher than a predetermined reference reliability than when the reliability is equal to or lower than the reference reliability;
A correction position specifying program for causing a computer to execute.

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