JP4200905B2 - Road information correction device - Google Patents

Description

  The present invention relates to a road information correction device that corrects road information stored in road information storage means based on travel locus information of a vehicle when traveling on an actual road.

  As a usage example of a database for storing road information (hereinafter referred to as “road database” in the “Background Art” description column), there is one used in a navigation device mounted on a vehicle. Normally, in this type of navigation device, when a destination is set by a user such as a driver, the location information of the destination is retrieved from a map database, and further, the destination from the current location (for example, the current location of the vehicle). The shortest route to the location is searched from the road database, and the result is guided to the user via a display display. Another example of use of the road database is a vehicle control device that performs vehicle travel control based on road information in the road database.

  As described above, since the road database is used for the route search of the navigation device and the like, in general, the width of the road, the gradient, the cant, the bank, the road surface state, the number of road lanes, the point where the number of lanes decreases, the width of the road is narrow. Such as the radius of curvature of the curve, intersection, T-junction, entrance of the curve, railroad crossing, highway exit rampway, highway tollgate, downhill road, uphill road, road type (national road, general road, It consists of various road information such as expressways, etc., and is created based on a 1/25000 scale map created mainly by the Geographical Survey Institute.

  By the way, in such a 1/25000 scale map, even if the error between the actual road and the road on the map is 0.3 mm on the map, it is 7.5 m when converted to the actual distance (1/1 scale). This is a considerable error. In addition, in places where hairpin curves are continuous or where multiple roads are connected, it is difficult to draw on the map. For example, on the map, the road is moved within a range of 1.2 mm. Shifting work is performed as necessary, and roads with road widths of 25 meters or more are drawn with a width smaller than 1/25000 scale. For this reason, the actual road (hereinafter referred to as “real road”) and the road on the map have different exit positions and curvature radii, or the road information on the map indicates that the road has a width of 25 m or more. It looks as if the width of the road below it is the same road width.

  Such a discrepancy between the road on the map and the actual road is considered to hardly have a significant influence on the search result in the route search scene such as that by the navigation device described above. Since the vehicle position in the middle and the current position on the display display are not correctly map-matched, the driver or the like of the vehicle can feel uncomfortable. Also, in the case of a vehicle control device, the accuracy of the road information can greatly affect steering control, drive control, braking control, etc., so when the road on the map does not match in units of meters on the actual road, There is a possibility that the traveling control corresponding to the actual road may be hindered.

  Therefore, in order to solve such a problem, the present inventor proposes a “database correction apparatus and a database correction method”, and makes a vehicle travel a predetermined section in order to obtain a travel locus by a gyro sensor, etc. Disclosure of technology for correcting road information in the road database based on the obtained travel trajectory data, technology for dividing the section traveled by the vehicle in consideration of cumulative error when the distance of the section becomes long, etc. (Patent Document 1 below).

JP 2001-141467 A (2nd to 18th pages, FIGS. 1 to 31)

  However, according to the “database correction device and database correction method” disclosed in Patent Document 1, for example, when it is determined whether the road database needs to be corrected, the trajectory coordinates of the trajectory start point in the node data on the database The node coordinates of the end point are pasted to correspond (Patent Document 1; paragraph number 0065, etc.). Therefore, it is necessary to specify a reference point on the road data in the road database (hereinafter referred to as “road information” in the “Background Art” description column).

  In other words, the starting point of the travel locus data is set to the point where the straight line section ends with reference to the point at which the straight section ends on the road data (that is, the start point of the curve), and then the road shape and the traveling locus based on the road data are set. Compare the shapes. This is because, when comparing the road shape based on the road data with the travel locus shape, it is difficult to make a comparison unless one of the two points is matched with some reference point. However, even if such a reference point is provided, the position of the reference point greatly affects subsequent comparisons, corrections, etc., and therefore the results of correction differ depending on how the reference point is provided (position to be set). Therefore, there is a problem that it is difficult to match the road shape with the corrected road data with the shape of the actual road.

  Further, in the travel locus data, the entire travel locus obtained therefrom shows the original road shape, while the road data on the road database generally represents only a general road shape. For this reason, the road shape obtained from such road data is strictly different from the actual road in many cases. Therefore, when correcting road data that is not necessarily accurate based on the travel locus data, If an arrangement method in which the reference points are attached as described above is employed, it is difficult to improve the accuracy of the arrangement of the travel locus. Therefore, even in such a case, there is a problem that it is difficult to match the road shape based on the corrected road data with the shape of the actual road.

  Furthermore, when such a reference point is provided, it is constrained by the reference point, so that the reference point also reduces the degree of freedom of alignment between the two, and thus the accuracy of the traveling locus is reduced. Can also be a cause of failure of proper placement.

  On the other hand, when it is attempted to compare the road data and the travel trajectory without providing such a reference point, how to specify the section to be compared becomes a problem. For example, if comparison is made in one curve section on the assumption that the road data generally matches the actual road shape, the road shape becomes asymmetric between the inner lane and the outer lane of the curve. For this reason, when an attempt is made to align the travel locus based on the road data, the position where the travel locus data is arranged can be shifted to the inner lane or the outer lane of the curve due to the asymmetry. For this reason, even in such a case, it is difficult to improve the accuracy of the arrangement of the travel locus, and as a result, there is a problem that it is difficult to match the road shape based on the corrected road data with the shape of the actual road.

  Regardless of the presence or absence of such a reference point, for a curve having an S shape such as a combination of a right turn curve and a left turn curve, that is, a so-called S curve, the road shape and the shape of a running locus based on road data are used. When comparing and positioning, it is more difficult to arrange the travel trajectory than when only a simple right turn curve or a left turn curve is used.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is road information capable of matching the road shape based on the road information stored in the road information storage means with the shape of the actual road. It is in providing the correction apparatus.

  In order to achieve the above object, in the road information correction device according to claim 1 described in the claims, the road information stored in the road information storage means is used as a travel locus of the vehicle when traveling on an actual road. A road information correction device that corrects based on information, wherein a curve section specifying a section having a curved road shape obtained from the road information stored in the road information storage means as a curve section in the road information Means, travel trajectory information acquisition means for acquiring travel trajectory information obtained by traveling on an actual road for the curve section, “road shape obtained from road information of the curve section” and “travel trajectory of the curve section” The travel locus of the curve section with respect to the road shape of the curve section so that the average value of the distance between the two shapes of the “travel locus shape obtained from information” is minimized. The traveling trace arrangement means for arranging the Jo, and technical features in that it comprises a curve section correction means for correcting the road information of the curve section on the basis of the traveling locus information of the arranged curve section.

  Further, in the road information correcting device according to claim 2, wherein the travel locus arranging means includes the “road shape obtained from the road information of the curve section” and “the curve”. The traveling locus shape obtained from the traveling locus information of the section ”is arranged on the same virtual plane, and the plurality of predetermined points set on the road shape and the traveling locus set corresponding to the plurality of predetermined points A technical feature is to minimize the average value of distances between a plurality of corresponding points on the shape.

  Furthermore, in the road information correcting device according to claim 3, wherein the curve section correcting means is adjacent to both sides of the curve section to be corrected in claim 1 or claim 2. The technical feature is that the road information of the curve section is corrected by connecting both ends of the travel locus shape of the arranged curve section to the road shape based on the respective road information.

  Furthermore, in the road information correction device according to claim 4 described in the claims, the road curve specifying means according to any one of claims 1 to 3, wherein the road curve specifying means includes a right turn curve as the curve section. A technical feature is to specify an S-shaped curve in combination with a left turn curve.

  Further, in the road information correcting apparatus according to claim 5, wherein the S-curve is the first curve in which the traveling direction in the road shape is changed from a right turn to a left turn. The left turn curve from point 2a to point 2a where the direction of travel changed from left turn to right turn, and the point from point 2a to point 3a where the direction of travel changed from right turn to left turn. And when the travel direction in the road shape changes from a left turn to a right turn to a second b point where the travel direction changes from a right turn to a left turn. The right turn curve and the left turn curve from the second b point to the third b point where the traveling direction has changed from a left turn to a right turn. That.

  In the invention described in the claims, the section in which the road shape obtained from the road information stored in the road information storage means is curved is specified as the curve section in the road information by the curve section specifying means, The trajectory information acquisition means acquires travel trajectory information obtained by traveling on an actual road for a curve section. Then, the travel locus arranging means minimizes the average distance between the two shapes “the road shape obtained from the road information of the curve section” and “the travel locus shape obtained from the travel locus information of the curve section”. Then, the travel locus shape of the curve section is arranged with respect to the road shape of the curve section, and the road information of the curve section is corrected by the curve section correction means based on the travel locus information of the arranged curve section. In addition, the travel locus arranging means places “the road shape obtained from the road information of the curve section” and “the travel locus shape obtained from the travel locus information of the curve section” on the same virtual plane, and sets them on the road shape. The average value of the distances between the plurality of predetermined points and the plurality of corresponding points on the travel locus shape set in correspondence with the plurality of predetermined points is minimized (claim 2). Further, the curve section correcting means connects the both ends of the travel locus shape of the arranged curve section to the road shape based on the respective road information adjacent to both sides of the curve section to be corrected, so that the curve section of the curve section is corrected. The road information is corrected (claim 3).

  As a result, when comparing the “road shape obtained from the road information of the curve section” and the “travel shape of the road section obtained from the curve information of the curve section”, both shapes do not coincide with each other at any reference point. The travel locus shape of the curve section is arranged with respect to the road shape of the curve section so that the average value of the distance between the shapes is minimized. Preferably, a plurality of predetermined points set on the road shape by arranging the “road shape obtained from the road information of the curve section” and the “travel shape of the road obtained from the travel locus information of the curve section” on the same virtual plane. And the average value of the distances between the plurality of corresponding points on the travel locus shape set corresponding to the plurality of predetermined points (claim 2). Then, the road information of the curve section is corrected by connecting both ends of the travel locus shape of the arranged curve section to the road shape based on the road information adjacent to both sides of the curve section to be corrected (claims). 3). Therefore, since it is possible to place the travel locus shape at a position where the road shape and the travel locus shape better match without being constrained by such a reference point, the road information stored in the road information storage means It is possible to match the shape of the road and the shape of the actual road.

  In the invention described in the claims, the road curve specifying means specifies an S-curve as a curve section by a combination of a right turn curve and a left turn curve (claim 4). Further, the S-curve is a left-turn curve from a point 1a where the traveling direction in the road shape has changed from a right turn to a left turn to a point 2a where the traveling direction has changed from a left turn to a right turn. A right turn curve from the point 2a to the point 3a where the traveling direction has changed from a right turn to a left turn, and the traveling direction in the road shape has changed from a left turn to a right turn From the 1b point to the right turn curve from the 1b point to the 2b point where the turning direction has changed from a right turn to a left turn, and from the 2b point to the 3b point where the advancing direction has changed from a left turn to a right turn. And a left turn curve. (Claim 5)

  As a result, it is possible to specify a curve section even for an S-curve, in which it is difficult to place a travel locus, as compared with a simple right-turn curve or a left-turn curve alone. Similarly to the above, when comparing the road shape and the travel locus shape, the curve is set so that the average value of the distance between the two shapes is minimized without matching the two shapes at some reference point. Place the trajectory shape of the curve section with respect to the road shape of the section, and arrange both shapes on the same virtual plane so that the predetermined points set on the road shape and the predetermined points are set. The average value of distances with a plurality of corresponding points on the traveling locus shape set correspondingly can be minimized. Therefore, the road shape based on the road information stored in the road information storage unit and the shape of the actual road can be made to coincide with the S-shaped curve as described above.

Hereinafter, an embodiment in which a road information correction device of the present invention is applied to a vehicle-mounted navigation device will be described with reference to FIGS.
First, the configuration of the navigation device 20 according to the present embodiment will be described with reference to FIG.
As shown in FIG. 1, the navigation device 20 can be mounted on a vehicle 50, and mainly includes a CPU 21, a memory 22, a database 23, an input / output interface 24, an input device 25, a display 26, a sound source unit 28, a GPS. The sensor 31 includes a vehicle speed sensor 32, a gyro sensor 33, a geomagnetic sensor 34, a communication device 35, and the like. FIG. 1 shows a state where the vehicle 50 is traveling on an actual road 90.

  The navigation device 20 is configured to be able to function as a computer by a CPU 21, a memory 22, a database 23, an input / output interface 24, an input device 25, a display 26, and the like, and the hardware is configured as follows. ing.

  The CPU 21 is a central processing unit that controls the navigation device 20, and is connected to a memory 22, a database 23, an input / output interface 24, and the like via a system bus. In addition to the system program 22a for controlling the CPU 21, the memory 22 stores various control programs 22b to 22g. The CPU 21 reads these programs from the memory 22 and executes them sequentially. The CPU 21 has a built-in clock 21a having a function of measuring the current time.

  The memory 22 is a storage device connected to the system bus, and constitutes a main storage space used by the CPU 21 (ROM, RAM, etc.). In the memory 22, a system program 22a, an input program 22b, a route search program 22c, a map matching program 22d, a database correction program 22e, a route guidance program 22f, an output program 22g, etc. are written in advance.

  The database 23 is a hard disk, a compact disk, a digital versatile disk, or the like that constitutes an auxiliary storage space used by the CPU 21, and is connected to the CPU 21 via a system bus. The database 23 stores map information 23a and road information 23b. Here, “road information” refers to various information such as topography of roads and rivers, road links (numbers, link lengths, link turning angles, etc.), nodes (numbers, coordinates, etc.), and the like. The “road link” means an individual line segment when an actual road is modeled as a set of short line segments, and is an individual straight line portion when an actual road is approximated by a broken line. This road link is usually uniquely defined by the coordinate values of the longitude and latitude (east longitude north latitude) corresponding to the actual road at both ends of the straight line portion, and depends on the distance cost depending on the length of the distance. Weighting information and the like are added. Then, by plotting the coordinate values of longitude and latitude of each road link on the coordinate system of east longitude and north latitude, the position and shape of the road are expressed as a map. The database 23 may correspond to “road information storage means” described in the claims.

  The input / output interface 24 exchanges data between an input / output device such as an input device 25, a display 26, a sound source unit 28, a GPS sensor 31, a vehicle speed sensor 32, a gyro sensor 33, a geomagnetic sensor 34, a communication device 35, and the CPU 21 and the like. It is a device that mediates and is connected to the system bus.

  The input device 25 is an input device provided on the operation panel of the navigation device 20, and is connected to the system bus via the input / output interface 24. The input device 25 is used for inputting information on a destination, a departure place, and the like that the driver or passenger (hereinafter simply referred to as “user”) of the vehicle 50 desires to search for a route through the input program 22b. is there. In general, a configuration in which a predetermined number of push-type switches are arranged is adopted. However, a navigation device that recognizes a touch panel type provided on the surface of the display 26 or a user's voice in consideration of simplification of input operation. Some of them are composed of a microphone and a voice recognition device that converts the information into input information to 20.

  The display 26 is a display device that can output a guide route from the departure point to the destination, the current position of the vehicle 50, road traffic information, and the like via the output program 22h, and is provided on the operation panel of the navigation device 20. The display 26 is also connected to the system bus via the input / output interface 24, and is constituted by, for example, a liquid crystal display, a CRT display, or a plasma display. Some display screens include a touch panel constituting the input device 25.

  In this embodiment, the input device 25 and the display 26 are provided on the operation panel of the navigation device 20. However, the present invention is not limited to this, and the input device 25 and the navigation device 20 are provided in a separate housing. The display 26 may be configured. Alternatively, the input device 25 and the display 26 may be physically separated from each other.

  The sound source unit 28 converts a digital signal based on predetermined audio data into an analog signal, and then can generate an audible sound from a speaker via an amplifier using the analog signal. The sound source unit 28 is connected to the system bus via the input / output interface 24. It is connected to the. As a result, route guidance or the like is output by voice from the speaker and notified to the user.

  The GPS sensor 31 is for outputting the current position data of the vehicle according to longitude and latitude, and is connected to the system bus via the input / output interface 24. The GPS sensor 31 includes a GPS receiver that receives signals from a plurality of GPS satellites and measures the absolute position of the user.

  The vehicle speed sensor 32, the gyro sensor 33, and the geomagnetic sensor 34 are for measuring the relative position of the vehicle and the traveling direction of the vehicle, and are connected to the system bus via the input / output interface 24, respectively. These sensors are used for autonomous navigation and the like. The relative position information of the vehicle obtained by the vehicle speed sensor 32 and the gyro sensor 33 is obtained in a tunnel where the GPS receiver cannot receive radio waves from the satellite. Or for correcting a positioning error of an absolute position measured by a GPS receiver. Further, the traveling direction information of the vehicle obtained by the gyro sensor 33 and the geomagnetic sensor 34 is used to correct the road information 23b of the database 23 as described later together with the relative position information of the vehicle.

  Although not shown, the steering device of the vehicle 50 is provided with a steering angle sensor capable of detecting the steering angle of the steering wheel, and the steering angle output from the steering angle sensor via the input / output interface 24. The signal can be input to the CPU 21. Thereby, CPU21 can acquire the steering direction of the said vehicle 50 by a driver | operator as steering angle information.

  The communication device 35 is a wireless communication device for transmitting / receiving data via a wireless communication line to / from an information center (not shown) such as a road traffic information distribution system center (VICS). Connected to the bus. For example, a wireless communication system such as a mobile phone or PHS is used. VICS is a registered trademark of the Road Traffic Information Communication System Center.

  Since the vehicle speed sensor 32 is configured to be able to detect the traveling speed of the vehicle 50, the CPU 21 integrates the vehicle speed data input from the vehicle speed sensor 32 to the CPU 21 via the input / output interface 24. By doing so, the travel distance of the vehicle 50 can be obtained. Further, since the gyro sensor 33 is configured to be able to detect the rotational angular velocity of the vehicle 50, the CPU 21 integrates the rotational angular velocity data input from the gyro sensor 33 to the CPU 21 via the input / output interface 24. Thus, the turning angle of the vehicle 50 can be obtained. Thus, the current position can be detected without using the GPS sensor 31 by combining the distance obtained by the vehicle speed sensor 32 and the CPU 21 and the direction detected by the geomagnetic sensor 34 and the gyro sensor 33. . The current position can also be detected by combining the distance obtained by the vehicle speed sensor 32 and the CPU 21 and the rudder angle detected by the rudder angle sensor (not shown).

  Here, an outline of the input program 22b, the route search program 22c, the map matching program 22d, the database correction program 22e, the route guidance program 22f, and the output program 22g stored in the memory 22 will be described.

  The system program 22a has a function of controlling basic operations from starting to stopping of the navigation device 20, and performs, for example, basic control processing shown in FIG. In this process, as described later, once a destination is set by the user of the navigation device 20, a route to the destination is searched, and then a map matching process (S107) → database correction process (S109) → Route guidance processing (S111) is repeatedly executed continuously, and the processing is terminated by setting the next destination or turning off the ignition switch. Accordingly, during this period, necessary correction processing is continuously performed on the road information 23b in the database 23. Therefore, the road on the map according to the road information 23b and the actual road on which the vehicle 50 is traveling do not match. The road information 23b can be appropriately corrected. This correction process is performed by the database correction program 22e.

  The input program 22b provides the user with various information necessary for using the navigation function, such as information on the destination desired by the user of the navigation device 20, route information, etc., and other information necessary for using the navigation function. And has a function of passing it to another program or process. Further, the input program 22b includes current position data output from the GPS sensor 31, vehicle speed data output from the vehicle speed sensor 32, rotational angular velocity data output from the gyro sensor 33, direction data output from the geomagnetic sensor 34, or CPU 21. It also has a function of inputting current time data and the like output from the clock 21a and passing it to other programs and processes.

  The route search program 22c has a function of searching for a destination input by the input device 25 based on the map information 23a stored in the database 23, and a departure place or GPS sensor 31 input by the input device 25 is detected. And a function for searching for the shortest distance route from the current location of the vehicle to the desired destination based on the road information 23b recorded in the database 23. The “shortest distance route” is a route having the shortest total distance from the departure point (or current location) to the destination.

  The map matching program 22d has a function of acquiring information on the current position of the vehicle 50 to be displayed on the display 26 from the map information 23a, road information 23b, various sensors, etc. in the database 23 and outputting the information as travel state data. For example, the map matching process shown in FIG. 3 is performed.

  The database correction program 22e has a function of correcting the road information 23b stored in the database 23 based on the running state data output by the map matching program 22d. For example, the database correction process shown in FIG. I do. The database correction program 22e corresponds to “curve section specifying means”, “running locus information acquiring means”, “running locus arrangement means”, and “curve section correcting means” described in the claims. .

  The route guidance program 22f displays information about the route searched by the route search program 22c (for example, explanation of the direction of travel such as right and left turn, road traffic information, etc.) on the display 26 for the user and an image or sound source It has a function to be performed by synthetic speech output by the unit 28 or the like.

  The output program 22g has a function of drawing various screen information as a diagram on the display 26 and a function of outputting various guidance information from the speaker by the sound source unit 28. For example, based on the map information 23a and road information 23b in the database 23, the map and the shortest distance route searched by the route search program 22c are displayed on the display 26, and the message sound and voice necessary for route guidance etc. Is sounded by the sound source unit 28 based on predetermined audio data.

  Next, the flow of basic control processing executed by the CPU 21 of the navigation device 20 will be described with reference to FIGS. This basic control process is executed by the system program 22a.

[Figure 2: Basic control processing]
As shown in FIG. 2, in the basic control process, an initialization process is first performed in step S101. In this initialization process, for example, a predetermined work area is secured in the memory 22, or various flags are set to initial values.

  Subsequently, the destination setting process is performed from step S103. In this process, for example, information on route search conditions such as whether to give priority to a destination, a passing point to the destination or, if necessary, a general road / toll road through the input device 25 by the user's operation Is input. The destination set by this process is uniquely determined based on the map information 23a in the database 23, for example, by coordinate information based on longitude / latitude (northern latitude).

  In the next step S105, route search processing is performed. This process is performed by the route search program 22c. Specifically, for example, the shortest distance route from the current position of the vehicle 50 acquired by the GPS sensor 31 to the destination set in step S103 is based on the map information 23a and the road information 23b in the database 23. A route search process is performed by a search algorithm such as the Dijkstra method.

  When a route search is thus performed in step S105, map matching processing is performed in the subsequent step S107. Specifically, as shown in FIG. 3, the current position on the guidance screen displayed on the display 26 is changed in real time by the route guidance processing in step S111, and the guidance route is traced as the vehicle 50 travels. A process of outputting route guidance data and travel state data necessary for obtaining the data is performed.

[Figure 3: Map matching process]
Here, an outline of the map matching process will be described with reference to FIG.
As shown in FIG. 3, in the map matching process, first, a process of reading a sensor signal is performed in step S201. In this process, various sensor signals (sensor data) output from the GPS sensor 31, the vehicle speed sensor 32, the gyro sensor 33, and the geomagnetic sensor 34 are read via the input / output interface 24, thereby performing a predetermined calculation in the subsequent step S203. Data near the current location including the current position of the vehicle 50 is acquired by the processing.

  In the subsequent step S205, route guidance data for guiding the route corresponding to the change in the current position accompanying the traveling of the vehicle 50 is output, and in addition, the traveling state data representing the traveling state of the vehicle 50 is output in step S207. Returning to the basic control process by the system program 22a shown in FIG. The traveling state data includes, for example, current time, gyro turning angle, vehicle speed, matching data (traveling road number, traveling node number, branch point passing flag), DB data (road number, node number, coordinates, link) Length, link angle) and the like. These data are output to the database correction program 22e described below, for example, via the work area of the memory 22.

[Figure 2: Basic control processing (continued)]
Returning to FIG. 2, when the map matching process is performed in step S107, the database correction process is performed in the subsequent step S109. This processing is performed by the database correction program 22e, and is applied to the “curve section specifying means”, “traveling locus information acquiring means”, “traveling locus arranging means” and “curve section correcting means” described in the claims. It is equivalent. Specifically, since it has been described in detail with reference to FIGS. 4 to 11, it will be described with reference to FIG.

[FIG. 4: Database Correction Process (S301: Travel Data Storage Process)]
As shown in FIG. 4, in the database correction process, first, a travel data storage process is performed in step S301. Since the details of this process are shown in FIG. 5A, the travel data storage process will be described here with reference to FIG.

[Figure 5: Travel data storage process]
As shown in FIG. 5A, in the travel data storage process, a process of calculating travel data is performed in step S401. This travel data corresponds to “travel locus information” described in the claims. Specifically, the following processes are performed on the travel data conceptually shown in FIG. FIG. 5B illustrates travel data representing data acquired according to the travel of the vehicle 50 based on the travel state data output by the map matching process shown in FIG. In the figure, x (cross) represents a node having a node number, and a straight line connecting these nodes represents a road link. In addition, a node surrounded by □ (white square) in x (cross) (node number -13 shown in FIG. 5B) indicates that the node is also a branch point. This branch point indicates that there are other adjacent roads connected to the branch point. In the example shown in FIG. 5B, the road number -345 The road and the road with the road number -346 are connected. In FIG. 5B, a road is shown as a travel locus. A circle (white circle) shown on the link indicates a matching point representing the current position based on matching data at a certain timing.

  First, in step S401, as a process for calculating travel data, calculation of travel distance and travel locus coordinates and setting of a node passing point flag are performed. Specifically, based on the vehicle speed V (i) at the matching timing t (i) and the time (traveling time) during which the vehicle 50 travels between the matching timings t (i), the travel locus length DL (i) is The travel locus coordinates (X (i), Y (i)) are calculated based on the turning angle θ (i) of the vehicle 50 and the travel locus length DL (i). Further, whether or not the traveling node number NN (i) has changed, that is, the traveling node number NN (i-1) at the previous matching timing t (i-1) and the current matching timing t (i). By determining whether or not the traveling node number NN (i) at the node matches, a node passing flag indicating whether or not the vehicle 50 has passed the node Nj is set. For example, if the traveling node number NN (i-1) and the traveling node number NN (i) match, the vehicle 50 has not passed through the node Nj. Set 0 (zero). On the other hand, if the traveling node number NN (i-1) and the traveling node number NN (i) do not match, the vehicle 50 has passed the node Nj, so 1 indicating that the flag is on is set to the node passing flag. Set to.

  Next, in step S403, as processing for storing the travel data, the travel trajectory length DL (i), trajectory coordinates (X (i), Y (i)) calculated in step S401 and the node passing flag are calculated. A process of storing in the predetermined area of the memory 22 together with other travel data is performed. Here, the traveling data stored in the memory 22 includes matching timing t (i), matching data, traveling road data, traveling locus data (hereinafter referred to as “trajectory data”), and the like. It consists of a number RN (i), a travel node number NN (i), a branch point passage flag, a node passage flag, and the like. Further, the road data is obtained from road number Rn (j), node number Nn (j), node coordinates (x (j), y (j)), link length LL (j), link angle α (j), etc. The trajectory data includes trajectory coordinates (X (i), Y (i)), turning angle θ (i), travel trajectory length DL (i), and the like. When the travel data storage process is performed in this way, the process returns to the database correction process shown in FIG. 4, and the process proceeds to step S303 subsequent to step S301. The trajectory data is stored at a predetermined interval, for example, every map matching timing. As a result, the trajectory data is stored as time-series data (the above processing is described in the claims). (Corresponding to “traveling track information acquisition means”).

[FIG. 4: Database correction processing (S303: DB correction range specifying processing)]
Returning to FIG. 4, in step S303, DB correction range specifying processing is performed. This process specifies the curve section of the road to be corrected based on the road information 23b in the database 23, and corresponds to “curve section specifying means” described in the claims. The details of this process are shown in FIG. 6, and the concept of road links based on the road information 23b is shown in FIG. 12. Here, the DB correction range specifying process will be described with reference to FIGS. To do. “DB” means a database. Further, x (cross) shown in FIG. 12 represents a node, and a straight line connecting these nodes represents a road link.

[FIG. 6: DB correction range specifying process]
As shown in FIG. 6, in the DB correction range specifying process, first, in step S501, the subscript i of the link turning angle α (i) is set to 0 (zero) and initialized. Here, the link turning angle α (i) indicates the link turning angle of the i-th road link. The “link turning angle α” is a value based on road link data constituting the road information 23b, and is defined by an angle formed by two adjacent road links. For example, in the conceptual example of the road link shown in FIG. 12 (example of road information 23b in which an actual road 90 is modeled as a set of road links), for the road link extending in the vehicle traveling direction from the node of the corrected section, The next road link adjacent to this road link has a link turning angle of 32 degrees in the direction of the curve that curves to the right in the vehicle traveling direction (hereinafter referred to as the “right turn curve”). 32 ”. In FIG. 12, the link turning angle in the direction of a curve that curves to the left in the vehicle traveling direction (hereinafter referred to as “left-turning curve”) is “+” (plus), and also turns right with respect to the vehicle traveling direction. “−” (Minus) is added to each link turning angle in the curve direction.

  In the subsequent step S503, processing for determining a node where the sign of the link turning angle α is reversed is performed. That is, by calculating α (i) × α (i−1), if the signs of the two adjacent road links do not match, the calculation result is negative (minus), so the sign mismatch, That is, the inversion of the sign is determined by whether or not the calculation result is 0 or less (α (i) × α (i−1) ≦ 0). For example, in the conceptual example of the road link shown in FIG. 12, the link turning angle of the node corresponding to the inverted portion of the sign is displayed in a square frame (+16 degrees, −32 degrees, +15 degrees shown in FIG. 12, -10 degrees, +11 degrees).

  If it is not determined that the sign of the link turning angle α is reversed (No in S503), the index i of the link turning angle α (i) is incremented (i = i + 1) in step S505, so that The sign reversal is determined for the link turning angle α (S503). On the other hand, if it is determined that the sign of the link turning angle α is reversed (Yes in S503), the process proceeds to the next step S507. Although not shown in FIG. 6, even if the subscript i of the link turning angle α (i) is increased to the value indicating the end of the road link data of the road information 23b, the entrance of the curve is detected in step S503. If not, the DB correction range specifying process is terminated, and the process returns to the database correction process shown in FIG.

  In the next step S507, a process of specifying and storing the (i-1) th node as a node at the curve entrance is performed. Specifically, for example, the node number of the node is stored in a predetermined area of the memory 22. For example, in the conceptual example of the road link shown in FIG. 12, the j = 1 curve α2 (1) with the turning angle of −32 degrees displayed as the right turn corresponds to this.

  When the node specified as the curve entrance node is stored in step S507, the subscript i of the link turning angle α (i) is incremented (i = i + 1) in step S509. Then, in step S511, as in step S503, processing for determining a node where the sign of the link turning angle α is reversed is performed. If it is not determined in step S511 that the sign of the link turning angle α is reversed (No in S511), the index i of the link turning angle α (i) is incremented again (i = i + 1) in step S509. The sign inversion is determined for the link turning angle α of the next node (S511). On the other hand, if it is determined that the sign of the link turning angle α is reversed (Yes in S511), the process proceeds to the next step S513.

  In the next step S513, a process of specifying and storing the i-th node as a curve exit node is performed. Specifically, for example, as in step S507, the node number of the node is stored in a predetermined area of the memory 22. For example, in the conceptual example of the road link shown in FIG. 12, the j = 2 curve α2 (2) of the turning angle +15 degrees displayed as the left turn corresponds to this. When determining the curve entrance, the node of (i-1) is specified as the entrance (S507), and when determining the curve exit, the node of i is specified as the exit of the curve entrance and exit so as to include the entire curve. This is to identify the node. When the process in step S513 is completed, the process returns to the database correction process shown in FIG. 4, and the process proceeds to step S305 subsequent to step S303.

  As described above, in this DB correction range specifying process, the curve entrance and exit are specified and stored in the memory 22, so the right turn curve entry / exit or the road link data constituting the road information 23 b of the database 23 is stored. The entrance / exit of the left turn curve can be specified. That is, it is possible to accurately grasp the entrance / exit of the curve on the road on the map.

  The DB correction range specifying process shown in FIG. 6 is a process that makes it possible to specify the entry / exit for a right turn curve or a left turn curve. Here, the entry / exit for a plurality of (two or more) curves. The “DB correction range specifying process corresponding to a plurality of curves” will be described with reference to FIG. 7 (in FIG. 7, it is simply expressed as “DB correction range specifying process”).

[FIG. 7: DB correction range identification process for multiple curves]
As shown in FIG. 7, in the DB correction range specifying process corresponding to a plurality of curves, first, in step S521, the subscript i of the link turning angle α (i) and the node number P (i) is set to 0 (zero), and the number of curves n is set. A process of setting to 0 (zero) and initializing is performed.

  In the subsequent step S523, as in the step S503 of the DB correction range specifying process described with reference to FIG. 6, a process for determining a node where the sign of the link turning angle α is inverted is performed. If it is not determined that the sign of the link turning angle α is reversed (No in S523), the index i of the link turning angle α (i) is incremented (i = i + 1) in step S525, so that the next node The sign reversal is determined for the link turning angle α (S523). On the other hand, if it is determined that the sign of the link turning angle α is reversed (Yes in S523), the process proceeds to the next step S527. Although not shown in FIG. 7, even if the subscript i of the link turning angle α (i) is increased to the value indicating the end of the road link data of the road information 23b, the entrance of the curve is detected in step S523. If not, the DB correction range specifying process is terminated, and the process returns to the database correction process shown in FIG.

  In the next step S527, a process of specifying and storing the (i-1) th node as the node of the first curve entrance is performed. Specifically, for example, the node number of the node is stored in a predetermined area of the memory 22. For example, in the conceptual example of the road link shown in FIG. 12, the j = 1 curve α2 (1) with the turning angle of −32 degrees displayed as the right turn corresponds to this. Note that the node numbers specified and stored in step S527 correspond to “point 1a” and “point 1b” described in the claims.

  If the node specified as the curve entrance node is stored in step S527, then in step S529, it is determined whether or not the distance from the first curve entrance to the P (i) th node is within a predetermined value. Is called. That is, when the distance from the first curve entrance to the currently detected node is calculated, that is, when the total length of a continuous curve (for example, an S-shaped curve) exceeds a predetermined distance (for example, 500 m) (No in S529), In order to correct the road information 23b in the database 23 at such a distance that the accumulated error of the gyro data by the gyro sensor 33 does not increase, the DB correction range specifying process corresponding to a plurality of curves is terminated and the process returns to the database correction process shown in FIG. . On the other hand, when the total length of the continuous curve from the first curve entrance is within the predetermined distance (Yes in S529), the process proceeds to step S531.

  In the following step S531, the subscript i of the link turning angle α (i) and the node number P (i) is incremented (i = i + 1). Then, in step S533, as in step S523, processing for determining a node where the sign of the link turning angle α is reversed is performed. If it is not determined in this step S533 that the sign of the link turning angle α is reversed (No in S533), the distance from the first curve entrance to the P (i) th node is within a predetermined value again in step S529. Whether or not is determined is performed. On the other hand, if it is determined that the sign of the link turning angle α is reversed (Yes in S533), the process proceeds to the next step S535.

  In step S535, the link turning angle α (i) from the entrance to the exit of each curve is integrated, and when the integrated value is not equal to or greater than a predetermined value, that is, when the curve is a curved road having a degree of undulation ( No in S535), because the curve is not enough to correct the road information 23b in the database 23. Therefore, the process proceeds to step S541 without performing the processes in the next steps S537 and S539, and the curve up to that point is corrected. Exclude from the target. On the other hand, when the integrated value of the turning angle from the nth curve entrance to P (i) is equal to or greater than the predetermined value (Yes in S535), the DB correction range specifying process described with reference to FIG. Similarly, in step S537, the i-th node is identified as the node at the n-th curve exit and stored. Specifically, for example, the node number of the node is stored in a predetermined area of the memory 22. For example, in the conceptual example of the road link shown in FIG. 12, j = 3 curve α2 (3) having a turning angle of −10 degrees corresponds to this. Note that the node numbers specified and stored in step S537 correspond to “point 3a” and “point 3b” described in the claims.

  In the subsequent step S539, a process of incrementing the value of n (n = n + 1) is performed in preparation for the next curve, and in step S541, the (i-1) th node is specified as the node at the entrance of the nth curve. The storing process is performed. Specifically, for example, the node number of the node is stored in a predetermined area of the memory 22. For example, in the conceptual example of the road link shown in FIG. 12, the j = 2 curve α2 (2) of the turning angle +15 degrees displayed as the left turn corresponds to this. Note that the node numbers specified and stored in step S541 correspond to “second point a” and “second point b” recited in the claims. Here, the entrance and exit of the curve are specified so as to include the entire curve. That is, since (i-1) is used at the curve entrance and i is used at the curve exit, the node at the curve exit and the node at the next curve entrance intersect in the continuous curve.

  When the process in step S541 is completed, the process proceeds to step S529, and a determination process is performed again as to whether or not the distance from the first curve entrance to the P (i) th node is within a predetermined value. Then, each process of steps S529 to S541 is repeated to detect a continuous curve, and when the entire length of the continuous curve becomes equal to or greater than a predetermined value (No in S529), as described above, DB correction corresponding to a plurality of curves is performed. The range specifying process is terminated, and the process returns to the database correction process shown in FIG.

  As described above, in the DB correction range specifying process corresponding to a plurality of curves shown in FIG. 7, a continuous curve can be detected. For example, an S-shaped curve or the like by a combination of a right turn curve and a left turn curve is converted into a right turn curve. Compared to the case where the left and right curves are individually identified by dividing the curve into left and right turn curves, the curve shape can be specified in the long distance section. Therefore, when matching the shape of the actual road with the shape of the actual road based on the road information 23b of the database 23, the matching error range (a range in which a deviation can occur) between them can be narrowed.

[FIG. 4: Database Correction Processing (S305: Correction Trajectory Data Acquisition Processing)]
Returning to FIG. 4, in step S305, correction locus data acquisition processing is performed. This process is to acquire the trajectory data of the vehicle 50 traveling on the actual road necessary for correcting the road information 23b of the database 23. In the “travel trajectory information acquiring means” described in the claims, Equivalent to. Details of this processing are shown in FIG. 8, sample data of the turning angle acquired by the gyro sensor 33 and the like are shown in FIG. 13, and the correspondence between the trajectory data and the road link by the road information 23b is shown in FIG. The correction trajectory data acquisition processing will be described here with reference to FIGS. 8, 13 and 14. Also refer to FIG. 12 as necessary.

[FIG. 8: Correction locus data acquisition processing]
As shown in FIG. 8, in the correction trajectory data acquisition process, first, in step S601, the subscript i of the node point N (i) is set to NS-2, and the trajectory data (turning angle data acquired by the gyro sensor 33). The initialization process for setting the data number k of 1) to 1 is performed. NS-2 set in the subscript i is a value representing a node point of x (cross) surrounded by □ (white square), that is, a starting point of acquisition of trajectory data, as shown in FIG. Is given based on the road information 23b.

  In the subsequent step S603, it is determined whether or not the vehicle 50 that has acquired the trajectory data has passed the node point N (NS-2) corresponding to the trajectory data acquisition start point due to its travel. If it cannot be determined by this process that the vehicle 50 has passed the node point N (NS-2) (No in S603), the data number k is incremented in step S605 (k = k + 1) to obtain the next data. ) Is performed. On the other hand, when it can be determined that the vehicle 50 has passed the node N (NS-2) (Yes in S603), the process proceeds to the next step S607.

  In the next step S607, the process of setting the subscript i of the node point N (i) to NS + 2 and the data number k when the vehicle 50 passes the node point N (NS-2) is stored in k1 ( k1 = k) is performed. As shown in FIG. 12, NS + 2 set to the subscript i is a value representing an x (cross) node point surrounded by □ (white square), that is, a trajectory data acquisition end point. Is given based on the road information 23b.

  In the subsequent step S609, the trajectory data acquired by the gyro sensor 33 is stored in a predetermined area of the memory 22, and further, in order to acquire the next data, the data number k is incremented in step S611 (k = k + 1). Processing is performed. Then, in the next step S613, processing is performed to determine whether or not the vehicle 50 has passed a node point N (NS + 2) corresponding to the end point of acquisition of trajectory data.

  If it cannot be determined in step S613 that the vehicle 50 has passed the node point N (NS + 2) (No in S613), the process proceeds to step S609 in order to save the acquired next data in the memory 22. Transition. On the other hand, if it can be determined that the vehicle 50 has passed the node point N (NS + 2) (Yes in S609), the process proceeds to the next step S615, and the vehicle 50 is moved to the node point N (NS + 2). ) Is stored in k2 (k2 = k). When the process in step S615 is completed, the process returns to the database correction process shown in FIG. 4, and the process proceeds to step S307 subsequent to step S305.

  Thus, the turning angle data of the vehicle 50 can be obtained by integrating the rotation angular velocity data input from the gyro sensor 33 to the CPU 21 by the CPU 21, so that the turning angle data of the vehicle 50 at each position is determined in advance. If the left turning angle is plotted as + (plus) and the right turning angle is plotted as-(minus) with the direction as the center (zero), it can be expressed as shown in FIG. Note that the solid black double circles ((A) to (E)) shown in FIG. 13 represent the entrance and exit of the curve described above.

  Further, by calculating the trajectory data based on the turning angle data, the correspondence between the trajectory data and the road link by the road information 23b can be obtained as shown in FIG. In FIG. 14, the passage trajectory data (black square) at the trajectory data acquisition start point shown in FIG. 13 is superimposed on the road link trajectory data acquisition start point □ (white square) based on the road information 23b shown in FIG. By setting the coordinates (X (1), Y (1)) to zero (X (1) = 0, Y (1) = 0), each locus data (turning angle data) with this coordinate as the origin And plotting sequentially for each data number k based on the distance traveled. As a result, as shown in FIG. 14, the traveling locus based on the pre-pasting locus data (X (k), Y (k) (k = k1 to k2)) is obtained as a collection exhibiting a (black dot) linear shape. Can do. 14 represents a link length corresponding point, and a straight line connecting the link length corresponding points represents a trajectory link (length G (1) to G (5)). In addition, the black and white double circles ((A) to (E)) shown in FIG. 14 represent the entrance and exit of the curve described above, and the circle (white circle) represents a point corresponding to the rear link length.

  The correspondence between FIG. 12 and FIG. 13 is as follows. As the turning angle data corresponding to the trajectory data acquisition start point □ (white square) shown in FIG. 12, the passing trajectory data (black square) at the trajectory data acquisition start point shown in FIG. 13 is acquired by the gyro sensor 33 and stored. (S609). Similarly, the correction section start point Δ (white triangle) shown in FIG. 12 and the passage trajectory data ▲ (black triangle) of the correction section start point shown in FIG. 13 and the correction section end point Δ (white triangle) shown in FIG. 13 is the trajectory data acquisition end point □ (white square) shown in FIG. 12 and the trajectory data ■ (black) of the trajectory data acquisition end point shown in FIG. Square) correspond to each. Also, for each node point between the correction section start point and the correction section end point, x (cross) shown in FIG. 12 corresponds to ● (black circle) shown in FIG.

[FIG. 4: Database Correction Processing (S307: Traveling Track Arrangement Processing)]
Returning to FIG. 4, in step S307, a travel locus arrangement process is performed. This process is performed so that the average value of the distance between the two shapes “the road shape obtained from the road information of the curve section” and “the travel locus shape obtained from the travel path information of the curve section” is minimized. The traveling locus shape of the curve section is arranged with respect to the road shape. That is, a road shape (synonymous with a road link) obtained from the road information 23b of the curve section to be corrected identified in step S303, and a travel locus shape based on the locus data of the curve section acquired in step S305, Is selected, the one with the smallest average distance between corresponding points calculated (referred to as LM value) is selected, and the locus data is arranged at that position. Here, the “distance between corresponding points” means that a road shape of a curve section and a travel locus shape of the curve section are arranged on the same virtual plane, and a plurality of predetermined points set on the road shape and the plurality of points This is the distance (LL (k) shown in FIG. 15) with a plurality of corresponding points on the travel locus shape set corresponding to a predetermined point. More specifically, “a plurality of points set on the road shape” are node points on the road data (joint points between adjacent road links). In addition, “a plurality of points on the travel locus shape” corresponding to these node points means the distance along the road link from the end point of the curve section to the node point, and the travel locus from the end point on the travel locus. It is a point on the travel locus where the distance is equal. The travel locus arrangement process corresponds to “travel locus arrangement means” described in the claims. Details of the travel locus arrangement process are shown in FIGS. 9 to 11 and a conceptual example of this process is shown in FIG. 15. Here, referring to FIGS. 9 to 11 and FIG. The travel locus arrangement process will be described.

[FIG. 9: Traveling track arrangement processing]
As shown in FIG. 9, in the travel locus arrangement process, a temporary arrangement process is performed in step S701. In this process, “road shape obtained from curve section road information” and “travel locus shape obtained from curve section road trajectory information” are temporarily placed on the same virtual plane. Performs a process of arranging the trajectory data acquired in step S305 approximately in accordance with the coordinate position on the coordinate plane (virtual plane) of the road information 23b of the curve section specified in step S303. The details of this processing are shown in FIG. 10, so here, the temporary placement processing will be described with reference to FIG.

[FIG. 10: Temporary placement processing]
As shown in FIG. 10, in the temporary placement process, first, in step S801, the subscript i of the east longitude coordinate ED (i) and the north latitude coordinate ND (i) of the node point is set to NS-2 (i = NS-2). When the link number kk is set to an initial value 1 (kk = 1), initialization processing is performed.

  In subsequent step S803, a start point coordinate provisional arrangement process is performed. That is, since kk is set to 1 and i is set to NS-2 in step S801, in this process, data number 1 is added to the data number k of the trajectory data (turning angle data) acquired by the gyro sensor 33. By setting the set kk, ED (NS-2) is set as the east longitude coordinate EG0 (1) and ND (NS-2) is set as the north latitude coordinate NG0 (1) as the start point coordinates.

  In the next step S805, a process of incrementing the suffix k of the east longitude coordinate EG0 (k) and the north latitude coordinate NG0 (k) of the starting point (k = k + 1) is performed, and a temporary trajectory coordinate calculation process is further performed in step S807. . As described with reference to FIG. 14, this coordinate calculation is based on the starting point coordinates (ED (NS-1), ND (NS-1)) as the origin, and each trajectory data (turning angle data) and its travel distance. Based on the above, the data number k incremented in step S805 is integrated and calculated (No in step S809). If it is determined in step S809 that the incremented data number k matches the data number k2 (Yes in S809), the temporary trajectory coordinate calculation for the data numbers k1 to k2 ends. Thereby, the coordinates of the point (corresponding point) on the travel locus corresponding to the node position of the road information 23b are obtained, and the locus data of the curve section is provisionally determined for the road information 23b. Note that the coordinate values of the nodes based on the road information 23b are (ED (k), ND (k)), and the coordinate values of the corresponding points on the temporarily placed travel locus are (EG0 (k), NG0 (k)). ).

  If it is determined in step S809 that the data number k matches the data number k2 (Yes in S809), the provisional trajectory coordinate calculation ends, so the present provisional arrangement processing is terminated and the traveling locus arrangement processing shown in FIG. Return to. The data number k2 is the number of trajectory data (turning angle data) acquired by the gyro sensor 33 when the vehicle 50 passes the node point N (NS + 2) (see FIG. 12).

[Fig. 9: Traveling track arrangement processing (continued)]
As shown in FIG. 9, the LM value calculation process in step S703 is performed after step S701. As shown in FIG. 15, this processing corresponds to a plurality of predetermined points ☆ (white stars) and ★ (black stars) set on the road shape (broken line shown in FIG. 15) of the road information 23b and the plurality of predetermined points. The process of minimizing the average value of the distances (corresponding point distances LL (K)) with a plurality of corresponding points × (cross) on the travel locus shape (solid line shown in FIG. 15) Specifically, the travel trajectory based on the trajectory data is gradually shifted in the east longitude direction and the north latitude direction on the coordinate plane (virtual plane), and the difference from the road shape by the road information 23b (corresponding point distance LL (K )) A process for obtaining an arrangement that minimizes the average value is performed. The LM value is a value that minimizes the average value of the distances between corresponding points. Details of this processing are shown in FIG. 11, and here, the LM value calculation processing will be described with reference to FIG.

[FIG. 11: LM Value Calculation Processing]
As shown in FIG. 11, in the LM value calculation process, first, in step S901, the LM value is set to the initial value 100 (LM = 100), and the shift amounts ΔE and ΔN are respectively set to the initial value −100 (ΔE = −100, ΔN = −100). Note that ΔE is the shift amount in the east longitude direction, and ΔN is the shift amount in the north latitude direction, which are gradually added, for example, by 1 second in step S915 described later.

  In subsequent step S903, processing for shifting corresponding points on the travel locus is performed. For example, as shown in FIG. 15, the shift amount with respect to the coordinate value (EG0 (k), NG0 (k)) of the corresponding point × (X) on the travel locus temporarily placed on the coordinate plane in step S701. A process of obtaining coordinates (east longitude coordinates EG (k), north latitude coordinates NG (k)) obtained by adding ΔE and ΔN and shifting in the east longitude direction and the north latitude direction is performed (EG (k) = EG0 (k) + ΔE). , NG (k) = NG0 (k) + ΔN).

In the next step S905, processing for calculating the distance between corresponding points is performed. That is, since the arrangement of the travel locus is shifted in the east longitude direction and the north latitude direction by the shift amounts ΔE and ΔN in step S803, the distance between the two shapes of the travel locus shape in this shifted state and the road shape based on the road information 23b ( Corresponding point distance LL (K)) is calculated between corresponding points. Specifically, as shown in FIG. 15, the node positions ☆ (white stars) and ★ (black stars) (ED (k), ND (k)) in the road information 23b are obtained by the temporary placement processing in step S701. Therefore, from the difference between this node position (ED (k), ND (k)) and the travel locus coordinates after the shift obtained in step S903 × (X) (EG (k), NG (k)), The distance LL (K) between corresponding points for each node is calculated (LL (k) = √ {(EG (k) −ED (k)) ² + (NG (k) −ND (k)) ² }, k1 ≦ k ≦ k2). Note that k is a link number, and its range is not less than the data number k1 and not more than the data number k2 of the curve section acquired in step S305. For example, in the example shown in FIG. 15, there is an S-shaped curve section from the start point inflection point ★ (black star) to the end point inflection point ★ (black star).

  In the subsequent step S907, processing for calculating the average value of the distances between corresponding points calculated in step S905 is performed. That is, in order to evaluate the degree of coincidence between the road shape based on the road information 23b and the shifted travel locus shape, here, the sum ΣLL (k) of the distance LL (K) between corresponding points for each node obtained in step S905. ) Is divided by the number of nodes n of the curve section to calculate the average value L_AVR of the distance between corresponding points (L_AVR = ΣLL (k) / n, k1 ≦ k ≦ k2).

  In step S909, processing is performed to determine whether or not the average value L_AVR of the distance LL (K) between corresponding points obtained in step S907 is equal to or less than the LM value (L_AVR ≦ LM). That is, when the average value L_AVR of the distance LL (K) between corresponding points is equal to or less than the LM value (Yes in S909), the arrangement of the travel locus shape shifted in step S903 is the same as the road shape according to the road information 23b. Since it can be evaluated that the degree of coincidence is high, the LM value and the like are updated in the next step S911. On the other hand, if the average value L_AVR of the distance LL (K) between corresponding points is not less than or equal to the LM value (No in S909), the arrangement of the travel locus shape shifted in step S903 matches the road shape according to the road information 23b. It cannot be evaluated that the degree is high. Therefore, without updating the LM value or the like, it is determined in step S913 whether or not the processes in steps S903 to S911 have been completed for both the shift amounts ΔE and ΔN.

  Step S911 is performed when it is evaluated that the arrangement of the shifted travel locus shape is highly consistent with the road shape according to the road information 23b, and the process of updating the LM value (LM = L_AVR) and at this time Processing for storing the shift amounts ΔE and ΔN as ΔEM and ΔNM, respectively, is performed.

  In the subsequent step S913, a process for determining whether or not the shift amounts ΔE and ΔN are each added to a predetermined value (for example, +100) is performed. That is, the shift amounts ΔE and ΔN are incremented by, for example, the minimum decomposition value (for example, equivalent to 1 second) of the road information 23b in step S915, so whether or not this addition is finished up to the predetermined value (+100). Judging. In addition, since the addition of the shift amounts ΔE and ΔN in step S915 is performed brute force, the above-described steps S903 to S911 are actually processed in a double loop having a so-called nesting relationship. In addition, the shift amounts ΔE and ΔN are added. However, in describing the flow of each process and in the flowchart representation of the drawing, the description is redundant, so in FIG. 11 the determination of the end of the double loop processing that has such a nested relationship is summarized in step S913. Note that this is expressed and the addition processing of the shift amounts ΔE and ΔN is also collectively expressed in step S915.

  When the LM value calculation process shown in FIG. 11 is completed in this way, the vehicle travels with the trajectory data that minimizes the average value L_AVR of the difference from the road shape (corresponding point distance LL (K)) by the road information 23b when the LM value is less than or equal to the LM value. Since the locus arrangement is obtained, the offset value composed of the LM value, ΔEM and ΔNM at this time is used as a return value, the running locus arrangement process shown in FIG. 9 is terminated, and the process returns to the database correction process shown in FIG.

[FIG. 4: DB correction data writing process (S309)]
Returning to FIG. 4, a DB correction data writing process is performed in step S309. This process corresponds to the “curve section correcting means” described in the claims, and for example, the road program 23b is written into the database 23 by the output program 22g. Specifically, since the offset value composed of the LM value, ΔEM, and ΔNM is returned as the return value by the travel locus arrangement process in step S307, the coordinates of the travel locus are based on these offset values in step S309. The trajectory data is arranged so that the value is closest to the road shape according to the road information 23b. Then, the road information 23b stored in the database 23 is overwritten by overwriting the old road information 23b as new road information 23b of the road in the curve section (S-curve section) with the trajectory data arranged in this way. To correct.

  At the time of this correction, the coordinates (ED (NS-1), ND (NS-1) of the start point of the curve section before correction are applied at the junction between the new curve section and the road information 23b adjacent thereto. ) Is replaced with the start point of the trajectory data. That is, before the correction, the coordinate value of the next node connected to the previous node (ED (NS-2), ND (NS-2)) of the correction section on the road information 23b is (ED (NS-1), ND (NS-1)) to (EG0 (k1) + ΔEM, NG0 (k1) + ΔNM). Similarly, the coordinate values of the next node connected to the next node (ED (NE + 2), ND (NE + 2)) after the end point of the correction section are (ED (NE + 1), ND ( NE + 1)) to (EG0 (k2) + ΔEM, NG0 (k2) + ΔNM). When such DB correction data writing process is completed, the database correction process shown in FIG. 4 is ended, and the process returns to the basic control process shown in FIG.

[FIG. 2: Basic Control Process (S111: Route Guidance Process)]
Returning to FIG. 2, when the database correction process in step S109 is completed, a route guidance process is performed in the next step S111. This process is performed by the route guidance program 22f, and, for example, information related to the route searched by the route search program 22c in step S105 (for example, an explanation of the traveling direction such as a right or left turn) as in the normal navigation process. Or road traffic information) is performed by an image displayed on the display 26 for the user, a synthesized voice output by the sound source unit 28, or the like. The road information 23b of the database 23 referred to at this time has been corrected to road information corresponding to the actual road by the gyro sensor 33 or the like by the steps S107 and S109 described so far. 50 positions and the current position on the screen display of the display 26 can be accurately map-matched. Therefore, it is difficult to give a sense of discomfort to the user (driver or the like) of the vehicle 50. Further, when the road information 23b in the database 23 is used in the vehicle control device, the highly accurate road information 23b can be provided to the vehicle control device. Control, drive control, braking control, and the like can be realized.

  As described above, according to the navigation device 20 according to the present embodiment, the following processes are performed by the database correction program 22e executed by the CPU 21. That is, the section in which the road shape obtained from the road information 23b stored in the database 23 is curved is specified as the curve section in the road information 23b by the DB correction range specifying process (S303), and the correction trajectory data acquisition process is performed. Through (S305), trajectory data obtained by traveling on an actual road is acquired for the curve section. Then, by the travel locus arrangement process (S307), the distance LL (K between corresponding points between the two shapes “the road shape obtained from the road information 23b of the curve section” and “the travel locus shape obtained from the curve data of the curve section”. ) Is set so that the average value L_AVR of the curve section is the minimum (LM value), and the road locus shape of the curve section is arranged with respect to the road shape of the curve section, and the road information of the curve section is based on the locus data of the arranged curve section. 23b is corrected by the DB correction data writing process (S309). As a result, when comparing the “road shape obtained from the road information 23b of the curve section” and the “traveling trace shape obtained from the curve data of the curve section”, the two shapes do not coincide with each other at any reference point. The travel locus shape of the curve section is arranged with respect to the road shape of the curve section so that the average value L_AVR of the distance LL (K) between the corresponding points between the shapes becomes the minimum (LM value). Therefore, since it is possible to arrange the travel locus shape at a position where the road shape and the travel locus shape better match without being constrained by such a reference point, the road information 23b stored in the database 23 can be used. It is possible to improve the accuracy by matching the road shape and the shape of the actual road.

  In addition, if this invention is grasped | ascertained as creation of a technical idea, it can also be expressed as follows. That is, (1) The present invention provides a road data storage means for storing road data representing a road shape by a series of coordinate values, and a section where the road is curved based on the road data (the section is referred to as “curve (Referred to as “section”), a curve section extracting means for extracting a section, a traveling locus acquisition means for acquiring a traveling locus when traveling on an actual road corresponding to the curve section, and the same coordinate system as the road data, A traveling locus arranging means for arranging the traveling locus in the coordinate system so that an average distance between the coordinate value of the traveling locus and the coordinate value of the road data of the curve section is minimized; and a road in the road data of the curve section. It can be expressed as a road data correcting device comprising a curve section correcting means for replacing the coordinate value with the coordinate value of the arranged traveling locus.

  Further, (2) the present invention is as follows: "In (1), the curve section correcting means is adapted to determine the coordinate values of both ends of the corrected road data and the coordinate values of the end points of each road data adjacent to both sides of the curve section. And the road data adjacent to both ends of the curve section and the road data of the corrected curve section can be expressed as “a road data correction device”.

  According to these (1) and (2), the curve section is extracted based on the road data by the curve section extraction means, and the travel locus when traveling on the actual road corresponding to the curve section is acquired by the travel locus acquisition means. Then, in the same coordinate system as the road data, the travel trajectory is arranged in the coordinate system by the travel trajectory arranging means so that the average distance between the coordinate value of the travel trajectory and the coordinate value of the road data of the curve section is minimized, By the curve section correcting means, the coordinate value of the road in the road data of the curve section is replaced with the coordinate value of the arranged traveling locus. Thereby, in the coordinate system, the travel distance and the road data are not matched at some reference point, and the travel distance is minimized so that the average distance between the coordinate value of the travel path and the coordinate value of the road data in the curve section is minimized. Since the trajectory is arranged in the coordinate system, the travel trajectory can be arranged at a position where the travel trajectory and the road data are better matched without being restricted by such a reference point. Therefore, the shape of the road based on the road data stored in the road data storage means and the shape of the actual road can be matched.

  In (1) and (2), the correspondence with the navigation device 20 and the like described above is as follows. The navigation device 20 is “road data correction device”, the database 23 is “road data storage means”, the CPU 21 is “curve section extraction means, travel locus acquisition means, travel locus arrangement means, curve section correction means”, database correction program 22e. Is “curve segment extraction means, travel locus acquisition means, travel locus arrangement means, curve interval correction means”, step S303 is “curve segment extraction means”, step S305 is “travel locus acquisition means”, and step S307 is “travel locus arrangement”. Means "and step S309 can respectively correspond to" curve section correcting means ". Further, “road data” corresponds to “road information” in the description of the navigation device 20 described above.

  In the above-described embodiment, the example in which the present invention is applied to the navigation device 20 mounted on the vehicle 50 has been described. However, the present invention is not limited to this, for example, a system including an information center and an in-vehicle device. It is also applicable to. That is, in the system in which the information center has a road database, the current position of the vehicle and the travel locus information are received from the in-vehicle device, and the road information in the road database is corrected based on the information, the present invention is applied to the information center. It can be applied to other computers.

It is a block diagram which shows the structural example of the navigation apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the flow of the basic control process by the system program of the navigation apparatus which concerns on this embodiment. It is a flowchart which shows the flow of the map matching process shown in FIG. It is a flowchart which shows the flow of the database correction process shown in FIG. FIG. 5 (A) is a flowchart showing the flow of the travel data storage process shown in FIG. 4, and FIG. 5 (B) is an explanatory diagram showing the concept of the travel data processed by the travel data storage process. It is a flowchart which shows the flow of DB correction range specific processing shown in FIG. It is a flowchart which shows the flow of DB correction | amendment range specification processing (multiple curve correspondence) shown in FIG. It is a flowchart which shows the flow of the correction locus | trajectory data acquisition process shown in FIG. It is a flowchart which shows the flow of the travel locus arrangement | positioning process shown in FIG. 10 is a flowchart showing a flow of temporary arrangement processing shown in FIG. 9. 10 is a flowchart showing a flow of LM value calculation processing shown in FIG. 9. It is explanatory drawing which shows the concept of the road link by the road information of a database. It is explanatory drawing which shows the sample data example of the turning angle acquired by a gyro sensor etc. It is explanatory drawing regarding the correction locus | trajectory data acquisition process shown in FIG. 8, and represents the example of locus | trajectory relative coordinate data. It is explanatory drawing regarding the driving | running | working locus | trajectory arrangement | positioning process shown in FIG. 9, and represents the example of arrangement | positioning of locus | trajectory data.

Explanation of symbols

20. Navigation device (road information correction device)
21 ... CPU (curve segment specifying means, travel trajectory information acquiring means, travel trajectory arranging means, curve section correcting means)
21a ... Clock 22 ... Memory 22a ... System program 22b ... Input program 22c ... Route search program 22d ... Map matching program 22e ... Database correction program (curve section specifying means, traveling locus information acquisition means, traveling locus arrangement means, curve section correction) means)
22f ... Route guidance program 22g ... Output program 23 ... Database (road information storage means)
23a ... Map information 23b ... Road information 24 ... Input / output interface 25 ... Input device 26 ... Display 28 ... Sound source unit 31 ... GPS sensor 32 ... Vehicle speed sensor 33 ... Gyro sensor 34 ... Geomagnetic sensor 35 ... Communication device 50 ... Vehicle 90 ... Actual road S303 (curve section specifying means)
S305 (travel locus information acquisition means)
S307 (running locus arrangement means)
S309 (curve section correction means)

Claims (5)

A road information correction device that corrects road information stored in a road information storage unit based on travel locus information of a vehicle when traveling on an actual road,
A curve section specifying means for specifying a section in which the road shape obtained from the road information stored in the road information storage means is curved as a curve section in the road information;
Traveling locus information acquisition means for acquiring traveling locus information obtained by traveling on an actual road for the curve section;
The road in the curve section so that the average value of the distance between the two shapes “the road shape obtained from the road information in the curve section” and “the travel locus shape obtained from the travel locus information in the curve section” is minimized. A travel locus arrangement means for arranging the travel locus shape of the curve section with respect to the shape;
Curve section correction means for correcting road information of the curve section based on the travel locus information of the arranged curve section;
An apparatus for correcting road information, comprising:   The travel locus arranging means arranges the “road shape obtained from the road information of the curve section” and the “travel locus shape obtained from the travel locus information of the curve section” on the same virtual plane, and 2. The average value of the distances between a plurality of predetermined points set in (1) and a plurality of corresponding points on the travel locus shape set corresponding to the plurality of predetermined points is minimized. Road information correction device.   The curve section correcting means connects the both ends of the travel locus shape of the arranged curve section to the road shape based on the road information adjacent to both sides of the curve section to be corrected, thereby connecting the curve section. The road information correcting device according to claim 1 or 2, wherein the road information is corrected.   4. The road information according to claim 1, wherein the road curve specifying unit specifies an S-curve as a combination of a right turn curve and a left turn curve as the curve section. 5. Correction device. The S-curve is
From the point 1a where the traveling direction in the road shape changes from a right turn to a left turn to the point 2a where the direction of travel changes from a left turn to a right turn, and from the point 2a A right turn curve from the right turn to the point 3a where the traveling direction has changed from a right turn to a left turn, and
From the point 1b where the traveling direction in the road shape has changed from a left turn to a right turn to the point 2b where the direction of travel has changed from a right turn to a left turn, and from the point 2b When the traveling direction is constituted by the left turn curve from the left turn to the third point b changed from the left turn to the right turn,
The road information correcting device according to claim 4, further comprising:

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