JP6169318B2 - Navigation system - Google Patents

Description

  The present invention relates to a navigation system that displays the current position of a vehicle and provides route guidance to a destination when the vehicle is traveling, and particularly detects that the vehicle is running backward on a road with a determined traveling direction. The present invention relates to a navigation system having a reverse running warning function for performing warnings.

  Conventionally, as a navigation system that detects and warns about the reverse running of the host vehicle, a database dedicated to reverse running detection with information about roads that are prohibited to reverse such as one-way roads (information on roads that are not allowed to reverse) is installed. A vehicle-mounted navigation system is known that issues a warning to the driver by voice and screen display when the traveling direction of the host vehicle does not match the travelable direction indicated by the reverse running prohibited road information (see Patent Document 1). . However, in the conventional car navigation system, it is necessary to prepare a dedicated database, and it is extremely difficult to prepare such a special database on a nationwide and global scale.

  By the way, in-vehicle navigation systems generally do not only receive GPS radio waves or process signals from various sensors to detect the latitude / longitude of the current position, but also detect the detected latitude / In order to eliminate the error of longitude, the present position of the own vehicle is specified using a method called map matching. That is, as map information, information including attributes of each road (road type, travelable direction, etc.) is stored in a storage device, and the own vehicle is in a vehicle travelable area, for example, on the road in accordance with the Road Traffic Act. On the assumption that the vehicle is traveling along the road traveling direction, the latitude / longitude of the detected vehicle is mapped on a map, and if the mapped position is not on the road or the traveling direction of the vehicle is If it does not coincide with the travelable direction on the road, a search is made for a position on another road that is closest to the map position and the travelable direction matches the travel direction of the host vehicle. It is specified as the position of the vehicle.

  FIG. 10 is a diagram showing an outline of the position specifying operation by the map matching described above, and shows that the host vehicle is traveling along the solid line 43 on the road 42. At this time, the navigation system mounted on the host vehicle periodically detects the host vehicle position based on reception information of GPS radio waves and information from various sensors included in the host vehicle, and obtains positioning results 52a to 52j. However, in general, the positioning result includes an error, and may indicate a position away from the road where the host vehicle exists, for example, as the positioning result 52c.

  For this reason, the navigation system performs map matching based on the map information provided by itself, and automatically locates the position 62c closest to the positioning result 52c (for example, the center portion of the width of the closest road) on the road 42 that is the travelable area. It is specified as the position of the vehicle. As a result, the result of specifying the position of the host vehicle is displayed as a point on the road 42 on the display device of the navigation system as shown in 62a to 62j. In this example, it is assumed that the traveling direction of the host vehicle is coincident with the travelable direction of the road 42, but the traveling direction of the road closest to the positioning result does not coincide with the traveling direction of the host vehicle. As described above, the navigation system searches for other roads in which the traveling direction and the travelable direction coincide with each other, and specifies the position of the host vehicle.

  A part of this map matching function is used, and the reverse detection is performed by using the information about the travelable direction of each road included in the map information, so that the reverse detection database described above is unnecessary. A running detection method is also known (see Patent Document 2). That is, in order to eliminate the latitude / longitude detection error for the vehicle position based on the GPS signal or the like, the vehicle position is specified only by matching the position represented by the detected latitude / longitude with the travelable area on the map. Then, the reverse traveling of the host vehicle is detected by determining the coincidence / inconsistency between the travelable direction at the specified position and the traveling direction of the host vehicle.

  However, in the conventional reverse running detection method disclosed in Patent Document 2, only a part of the map matching function, that is, the position of the vehicle from only the matching between the position detected based on the GPS and the road closest to the position. In order to detect the position, other part of the matching function, that is, the road where the traveling direction of the vehicle coincides with the travelable direction is not detected. The error may not be corrected sufficiently.

JP 2007-139531 A JP 2010-210435 A

  The present invention has been made in view of the above-described conventional problems, and its purpose is to use a special database for reverse running detection in a navigation system and without impairing the accuracy of vehicle position identification. It is to detect the reverse running of the vehicle appropriately.

  The present invention relates to a storage device that stores map information including a road map, a position detection unit that detects a current position of a vehicle, the current position detected by the position detection unit, and the map information stored in the storage device. And a map matching processing means for repeatedly specifying the position of the vehicle on the road based on a map matching process, wherein a temporal continuity with respect to the repeatedly specified position of the vehicle is provided. A navigation system configured to evaluate and determine whether or not the vehicle is in a reverse running state with respect to a travelable direction of the road based on a result of the evaluation.

  In another aspect of the present invention, the map information further includes link information indicating a connection state of each road, and the temporal continuity includes a road link including the position of the vehicle specified last time and a current time. Navigation that determines that the vehicle is in the reverse running state when it is continuity with a link of a road that includes the position of the identified vehicle and the two links do not match or are not connected System.

  In another aspect of the present invention, the temporal continuity is a continuity of distance between the vehicle positions that are repeatedly specified, and the position of the vehicle specified last time and the position of the vehicle specified this time The navigation system determines that the vehicle is in the reverse running state when the distance to the vehicle is equal to or greater than a predetermined value.

  In another aspect of the present invention, the map information includes information on a road attribute including a road type for each road, and the temporal continuity is a road attribute of a road including the position of the vehicle specified last time. A navigation system that determines that the vehicle is in the reverse running condition on the condition that the two road attributes are different from each other and the road attribute of the road including the position of the vehicle specified this time It is.

  In another aspect of the present invention, the map information includes information relating to a road attribute including a road type for each road and link information indicating a connection state of each road, and includes a position of the vehicle specified last time. The road attribute of the road including the position of the vehicle specified this time is different from the road attribute of the road including the position of the vehicle specified this time and the road link including the position of the vehicle specified last time When there is a change in road attribute on the link, or the road attribute of the road including the position of the vehicle specified last time is different from the road attribute of the road including the position of the vehicle specified this time, and The road attribute change point does not exist on the link group connected to the road link including the vehicle position specified last time and the road link including the vehicle position specified this time, Both are determined to be in said reverse run state, a navigation system.

  According to the present invention, in the navigation system, it is possible to appropriately detect reverse running of the host vehicle without using a special database for detecting reverse running and without impairing the accuracy of specifying the vehicle position.

It is a block diagram which shows the structure of the navigation system which concerns on one Embodiment of this invention. It is explanatory drawing about the link information which the map information storage part with which this navigation system is provided memorize | stores. It is explanatory drawing about operation | movement of the reverse running determination in this navigation system. It is a figure which shows an example of the reverse running warning message displayed on the display apparatus of this navigation system. It is a flowchart which shows the operation | movement procedure of this navigation system. It is a flowchart which shows the operation | movement procedure of the 1st modification of this navigation system. It is a flowchart which shows the operation | movement procedure of the 2nd modification of this navigation system. It is a flowchart which shows the operation | movement procedure of the 3rd modification of this navigation system. It is a flowchart which shows the operation | movement procedure of the 4th modification of this navigation system. It is explanatory drawing about operation | movement of map matching.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a navigation system 1 according to an embodiment of the present invention.
The navigation system 1 includes a position information detection unit 10, a processing device 20, a map information storage unit 12, a display device 14 including a liquid crystal display device, and a touch panel provided on the screen of the display device 14, for example. And an alarm device 18 constituted by a speaker or the like.

  The position information detection unit 10 determines the direction of the host vehicle in a horizontal plane and the tilt angle of the host vehicle with respect to the vertical direction (for example, the tilt angle of the vehicle longitudinal axis with respect to the vertical direction and the rotation angle around the vertical axis passing through the vehicle center of gravity. A gyro sensor 102 that detects a change amount of the tilt angle (for example, a yaw rate), a speed sensor 104 and an acceleration sensor 106 that detect the speed and acceleration of the host vehicle, and an artificial satellite, respectively. A GPS receiver 108 that receives a GPS (Global Positioning System) signal for measuring the position of the vehicle, and an ETC (Electronic Electronic) provided to the toll gate with information for specifying a toll gate when entering the expressway Toll Collection) ETC in-vehicle device 110 received from system device, VICS (registered trademark) (Vehicle Information and Communication System), etc. A beacon receiver 112 for receiving position information and road information, etc. from the beacon, the has.

  The map information storage unit 12 includes a storage device that stores map information. The map information includes road map data composed of topographic map data, road map data indicating the position of each road, link information indicating connection between roads, road attribute information indicating attributes of each road, and the like. And drawing data such as polygon data for displaying roads and buildings on the display screen of the device 14.

  Here, the link information usually includes nodes (coordinate points that become nodes such as intersections), links (minimum unit of the traveling path) that are lines connecting the nodes, and information about the distances of the links. , Is included. The road attribute information includes information on the type of each road (differentiation between national roads, prefectural roads, toll roads, etc.), shape, travelable direction, gradient, curvature, width, and the like. The map information storage unit 12 is configured by an arbitrary storage device that can read data by a computer, such as a hard disk drive or a data reading device corresponding to the storage medium into which a storage medium such as a CD or DVD is inserted. Can do.

  The processing device 20 is a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory) in which a program is written, a RAM (Random Access Memory) for temporary storage of data, and the like, for example, an electronic control unit (ECU) ).

  The processing device 20 includes an INS (Inertial Navigation System) positioning means 202, a GPS positioning means 204, a position detection means 206, a map matching processing means 208, a reverse running determination means 210, and a display control means. 212 and warning instruction means 214. Each of the above means is a function realizing means of the processing device 20 realized by the processing device 20 being a computer executing a program. The computer program can be stored in any computer-readable storage medium.

  Based on the principle of inertial navigation, the INS positioning means 202 calculates the travel distance for each traveling direction from information on the vehicle traveling direction from the gyro sensor 102 and information on the vehicle speed and acceleration from the speed sensor 104 and the acceleration sensor 106. The relative position from the starting point is detected by calculating and adding these vectors, and INS (Inertial Navigation System) positioning information representing the position of the host vehicle is output. The starting point can be acquired from, for example, the following GPS positioning means 204.

  The GPS positioning means 204 outputs GPS positioning information indicating the latitude and longitude of the vehicle position based on the GPS signal received by the GPS receiver 108.

  The position detection unit 206 detects the current vehicle position (latitude and longitude) from the INS positioning information and the GPS positioning information output from the INS positioning unit 202 and the GPS positioning unit 204. Further, when toll gate passage information from the ETC on-vehicle device 110, position information from the beacon receiver 112, and the like are obtained, the detected vehicle position is corrected based on these information. The detected (or corrected) host vehicle position is output to the map matching processing means 208.

  The correction of the detected vehicle position may be performed based on the assumption that the vehicle travels the route based on route information from the travel start position of the vehicle to the target position, for example. For such route information from the travel start position to the target position, for example, when the target position is input from the input device 16 by the occupant, the route search function (processing) normally provided in the navigation system is executed. Given by.

  Next, the map matching processing unit 208 executes map matching processing on the vehicle position detected by the position detecting unit 206 based on the map information from the map information storage unit 12 and the traveling direction information from the gyro sensor 102. .

  In this map matching process, a position on the road that is closest to the host vehicle position detected by the position detection unit 206 and matches the travel direction indicated by the travel direction information and the travelable direction is set as the current host vehicle position. Identify. Further, the map matching processing unit 208 stores the specified own vehicle position as travel history information in a non-volatile memory (not shown) in the processing device 20 and outputs it to the reverse travel determination unit 210 and the display control unit 212. To do. In addition, the specification of the own vehicle position by this map matching process is repeatedly performed, for example, at a predetermined time interval, and is stored and output.

  The display control unit 212 acquires map information around the host vehicle position from the map information storage unit 12 based on the host vehicle position output from the map matching processing unit 208, and displays the host vehicle position and the surrounding map. Display on the device 14. Further, the display control means 212 displays a warning message to the effect that there is a possibility of running backward on the display device 14 based on an instruction from a warning instruction means 214 described later.

  The reverse running determination means 210 is based on the current vehicle position output by the map matching processing means 208 and the vehicle position specified last time stored as the travel history information. The temporal continuity is evaluated to determine whether or not the host vehicle is running backward. This “temporal continuity” includes, for example, the relationship between roads including the position of the vehicle repeatedly identified (connectivity between roads and consistency of attributes), or the vehicle continuously identified. This includes continuity of distance between positions.

  In the present embodiment, the reverse running determination unit 210 refers to the link information included in the map information stored in the map information storage unit 12 and is previously identified as the road link including the current vehicle position identified this time. If the link of the road including the own vehicle position is specified and there is no connection between these two links, it is determined that the own vehicle is running backward. The determination result is output to the warning instruction unit 214.

  The warning instructing unit 214 emits an alarm sound or the like by the alarm device 18 when the reverse running determination unit 210 determines that the host vehicle is running backward, and performs reverse running to the display control unit 212. Give instructions to display a warning message to the effect that

  Next, an example of the reverse running determination operation of the navigation system 1 will be described with reference to FIGS. FIG. 2 is an explanatory diagram for the link information included in the map information stored in the map information storage unit 12, and FIG. 3 is an explanatory diagram for the reverse running determination operation in the navigation system 1.

  FIG. 2A is an example of a road, and shows a highway 30 and a general road 31 provided along the main line of the highway 30. The highway 30 includes a road 30a having an approach path for entering the highway 30 from the lower side in the figure and a road 30b having an exit path for exiting from the highway 30 to the lower side in the figure. Further, in FIG. 2A, the directions in which the road can travel are indicated by solid arrows. The map information stored in the map information storage unit 12 includes topographic map data of these roads and polygon data for drawing the roads on the display screen of the display device 14.

  FIG. 2B is a diagram showing a link for each road shown in FIG. 2A based on link information included in the map information stored in the map information storage unit 12. In FIG. 2B, a dotted line 41 indicates a link of the general road 31 in FIG. 2A. Moreover, the solid lines 40a and 40b of FIG. 2B have shown the link group which comprises the roads 30a and 30b which comprise the highway 30 in FIG. 2A, respectively. Here, the black circles shown on the solid lines 40a and 40b represent nodes, and the line connecting the black circles represents one link. Further, in the map information stored in the map information storage unit 12, the travelable direction for each of these links is recorded as road attribute information.

  In FIG. 3A, an example of a travel route of a vehicle entering the highway 30 shown in FIG. 2A (an example of reverse travel) is shown by vehicle positions 50a to 50d of the vehicle at regular intervals. FIG. 3B also shows own vehicle positions 60a to 60d that are specified by the navigation system 1 at regular intervals with respect to the travel route shown in FIG. 3A.

  The solid arrow shown in FIG. 3A indicates the correct traveling direction on the roads 30a and 30b, that is, the travelable direction as in FIG. 2A. Therefore, a vehicle that has entered from the lower side of the figure travels on the road 30a upward in the figure as shown by a dotted arrow in the figure, and then travels in the left direction in the figure through a curve, or in the right direction in the figure through a looped road portion. You have to drive towards.

  On the other hand, the vehicle travel route indicated by 50a to 50d in FIG. 3A enters the road 30b by running backward, travels from the bottom to the top in the figure, and then travels to the right in the figure through a curve. It has become.

At this time, the navigation system 1 mounted on the vehicle operates as follows.
First, the position detection unit 206 detects the host vehicle position based on information from the INS positioning unit 202, the GPS positioning unit 204, and the like, and the map matching processing unit 208 stores map information for the detected host vehicle position. Map matching is performed based on the map information stored in the unit 12. As a result, a position on the road that is closest to the detected own vehicle position and whose traveling direction matches the traveling direction of the own vehicle is specified as the own vehicle position. As a result, the position of the vehicle specified corresponding to the vehicle positions 50a to 50c shown in FIG. 3A is not on the link 40b corresponding to the road 30b on which the vehicle is actually traveling, but the traveling direction of the vehicle. And on the link 40a in which the travelable directions coincide with each other, and are specified as the own vehicle positions 60a to 60c as shown in FIG. 3B.

  Here, since all the own vehicle positions 60a to 60c are specified on one link included in the link 40a for the same road 30a, the reverse running determination means 210 determines that the own vehicle position 60b (or 60c). At the specified time point, it is determined that the link of the road including the vehicle position 60b (or 60c) specified this time and the link of the road including the vehicle position 60a (or 60b) specified last time match. The vehicle is determined not to run backward.

  On the other hand, when the own vehicle reaches the position of 50d in FIG. 3A, the map matching processing means 208 is closest to the own vehicle position detected by the position detecting means 206, and the road property traveling direction and the own vehicle traveling direction are determined. The vehicle position 60d is specified on the link 41 of the general road 31 outside the highway 30 as the position on the road where the two match.

  As a result, the reverse running determination means 210 is different from the link 41 of the general road 31 including the own vehicle position 60d specified this time and the link 40a of the road 30a of the highway 30 including the previous vehicle position 60c specified, And since there is no connection between the link 41 and the link 40a, it is determined that the host vehicle is running backward.

  Then, the result of the determination is displayed on the display screen 160 of the display device 14 by the display control means 212, for example, as shown in FIG. 4, the display 717 of the general road 31, the display 170 of the expressway 30, and the display 172 of the own vehicle. A warning message 173 is also displayed. Further, the warning is notified to the occupant as a warning sound or warning voice message from the warning device 18.

  As described above, in the reverse running determination by the reverse running determination unit 210, the relevance between roads including the vehicle position that is repeatedly identified (connectivity between roads and consistency of attributes) or continuous. Thus, the continuity of the distance between the vehicle positions specified in the above can be used as a criterion. Therefore, in the present embodiment, the criterion for the reverse running determination is “between the link of the road including the current vehicle position specified this time (current road) and the link of the road including the vehicle position specified last time (previous road). However, the present invention is not limited to this, and as is clear from FIG. 3B, simply “the link of the current road does not match the link of the previous road” or “ The road attribute (eg, road type) of the previous road is different ”or“ the road attribute of the current road is different from that of the previous road, and the link of the current road and / or the link of the previous road are connected to these links. There is no road attribute change point on the link group ”or“ the distance between the vehicle position specified this time and the vehicle position specified last time (the distance between the positions 60c and 60d in FIG. 3B) is a predetermined value or less. By it has ", it can be determined that the vehicle is run reverse.

  Next, the operation procedure of the navigation system 1 will be described with reference to the flowchart shown in FIG. This operation is repeated at predetermined time intervals by, for example, a timer (not shown) provided in the processing device 20.

  When the processing is started, first, the position detection unit 206 of the processing device 20 acquires INS positioning information and GPS positioning information from the INS positioning unit 202 and the GPS positioning unit 204, respectively (S101), and the acquired INS positioning information and Based on the GPS positioning information, the current vehicle position (latitude and longitude) is detected (S102). Here, the INS positioning means 202 acquires travel direction information from the gyro sensor 102, speed information from the speed sensor 104, and acceleration information from the acceleration sensor 106 at a constant time interval shorter than the predetermined time interval. It is assumed that the INS positioning information is updated based on the principle of inertial navigation. In addition, the GPS positioning means 204 receives a GPS signal by the GPS receiver 108 in response to a positioning information request signal from the position detection means 206, calculates GPS positioning information, and outputs it.

  Next, when the toll gate passage information for identifying the toll gate that has passed from the ETC onboard device 110 can be obtained from the ETC in-vehicle device 110, the position detecting means 206 acquires the information, and the beacon receiver 112 receives the radio beacon or When receiving the position information from the optical beacon, the position information is acquired from the beacon receiver 112 and based on the position information of the toll gate specified from the toll gate passage information or the position information from the beacon. Thus, the current host vehicle position detected in step S102 is corrected (S103). The corrected host vehicle position is output to the map matching processing unit 208 as the current host vehicle position detected by the position detecting unit 206.

  Next, the map matching processing unit 208 executes map matching processing (S104). That is, the travel direction information is acquired from the gyro sensor 102, the map information stored in the map information storage unit 12 is referred to, the vehicle position closest to the own vehicle position detected by the position detection means 206 in steps S102 and 103, and the above A road having a travelable direction that matches the travel direction indicated by the travel direction information as a road attribute is identified, and a position on the identified road that is closest to the detected vehicle position is identified as the vehicle position.

  Subsequently, the map matching processing means 208 stores the identified own vehicle position as travel history information in a nonvolatile memory (not shown) provided in the processing device 20 (S105). Here, in the travel history information stored in the non-volatile memory, the vehicle positions specified up to now are recorded in the specified order.

  The display control unit 212 acquires the current vehicle position specified this time from the map matching processing unit 208, acquires the acquired map information around the own vehicle position from the map information storage unit 12, and acquires the map and the surrounding map. The vehicle position is displayed on the display device 14 (S106).

  Next, the reverse running determination unit 210 determines whether or not the vehicle position specified last time is recorded in the travel history information stored in the nonvolatile memory (S107), and when it is not recorded (S107, No), the process is terminated as it is.

  On the other hand, when the own vehicle position specified last time is recorded in the travel history information (S107, Yes), it is specified this time with reference to the link information included in the map information stored in the map information storage unit 12. A road link including the current vehicle position (current link) and a road link including the vehicle position specified last time (previous link) are acquired (S108).

  Next, the reverse running determination means 210 determines whether or not the current link matches the previous link (S109). If they do not match (S109, No), the reverse run determination means 210 determines whether the current link and the previous link are the same. It is determined whether or not there is a connection (S110). When there is no connection (S110, No), the reverse running determination unit 210 determines that the host vehicle has run backward, and the warning instruction unit 214 that has received the determination instructs the display control unit 212, A reverse running warning message indicating the possibility of reverse running is displayed on the display device 14 (S111). Further, the warning instruction means 214 issues a reverse running alarm (for example, an alarm sound or an alarm voice message) indicating that there is a possibility of reverse running by the alarm device 18 (S112), and the process is terminated. .

  On the other hand, when the current and previous links match in step S109 (S109, Yes) and when there is a connection between the current and previous links in step 110 (S110, Yes), a reverse running warning message is displayed. The process ends without issuing a reverse running warning.

Next, a modified example of the navigation system 1 will be described.
As a first modification of the navigation system 1, the reverse running determination unit 210 includes a road link including the vehicle position specified this time (current link) and a road link including the vehicle position specified last time (previous link). ) Does not match, it is immediately determined that the host vehicle is running backward.
According to this modification, it is possible to simplify the reverse running determination and make a quick determination.

  Specifically, as shown in the flowchart of FIG. 6, when the current link and the previous link do not match in step S209 (S209, No), the reverse running determination means 210 causes the host vehicle to run backward. The warning instruction means 214 instructs the display control means 212 to display a reverse running warning message indicating that there is a possibility of reverse running on the display device 14 (S210). It is assumed that a reverse running warning indicating that there is a possibility that the vehicle is running is issued by the warning device 18 (S211), and the process is terminated. On the other hand, when the current link matches the previous link in step S209 (S209, Yes), the processing is terminated as it is. Since other steps S201 to S208 shown in FIG. 6 are the same as steps S101 to S108 shown in FIG. 5, the description of FIG. 5 described above is cited.

As a second modification of the navigation system 1, the reverse running determination unit 210 determines that the road attribute information of the road including the vehicle position specified this time does not match the road attribute information of the road including the vehicle position specified last time. Immediately determines that the host vehicle is running backward.
According to this modification, it is possible to simplify the reverse running determination and make a quick determination.

  Specifically, as shown in the flowchart of FIG. 7, the road attribute (current road attribute) of the road including the vehicle position specified this time in step S308 and the road attribute of the road including the vehicle position specified last time ( (Previous road attribute) is acquired from the road attribute information included in the map information stored in the map information storage unit 12 (S308), and the current road attribute and the previous road attribute do not match (S309, No), the reverse running determination means 210 determines that the host vehicle is running backward, and the warning instruction means 214 instructs the display control means 212 to indicate that there is a possibility of reverse running. A warning message is displayed on the display device 14 (S310), a reverse running alarm indicating that there is a possibility of reverse running is issued by the warning device 18 (S311), and the processing is terminated. On the other hand, when the current road attribute matches the previous road attribute in step S309 (S309, Yes), the processing is ended as it is. Since other steps S301 to S307 shown in FIG. 7 are the same as steps S101 to S107 shown in FIG. 5, the description of FIG.

As a third modification of the navigation system 1, the reverse running determination unit 210 includes a road attribute of a road (current road) including the vehicle position specified this time and a road (previous road) including the vehicle position specified last time. The vehicle is running backwards when the attribute does not match and there is no change in the road attribute on the link of the current road, the link of the previous road, or the link group connected to these links Is determined.
According to this modification, reverse running determination can be performed more appropriately using the road attribute information and link information of each road.

  Specifically, as shown in the flowchart of FIG. 8, in step S408, the road attribute (current road attribute) and link of the road (current road) including the vehicle position specified this time, and the vehicle specified last time The road attribute (previous road attribute) and link of the road including the position are acquired from the road attribute information and link information included in the map information stored in the map information storage device 12 (S408). If the current road attribute and the previous road attribute do not match (S409, No), whether there is a change in the road attribute on the link of the current road and the previous road or on the link group connected to the link. Judgment is made (S410). If there is no change in the road attribute (S410, No), the reverse running determination means 210 determines that the host vehicle is running backward, and the warning instruction means 214 is based on the determination, and the display control means 212 is determined. Is displayed on the display device 14 (S411), and a reverse running warning indicating that there is a possibility of reverse running is displayed. Issued by the device 18 (S412), the process is terminated.

  On the other hand, when the current road attribute matches the previous road attribute in step S409 (S409, Yes) and when there is a change in the road attribute in step 410 (S410, Yes), the reverse running warning message The process ends without displaying or issuing a reverse running warning. Since other steps S401 to S407 shown in FIG. 8 are the same as steps S101 to S107 shown in FIG. 5, the description of FIG.

As a fourth modified example of the navigation system 1, the reverse running determination unit 210 is configured such that when the distance between the vehicle position specified this time and the vehicle position specified last time is equal to or greater than a predetermined value, the host vehicle runs backward. It is determined that
According to this modification, reverse running determination can be performed immediately without referring to road attribute information or link information.

  Specifically, as shown in the flowchart of FIG. 9, whether or not the distance between the vehicle position specified this time (current position) and the vehicle position specified last time (previous position) is greater than or equal to a predetermined value in step S508. (S508, Yes), the reverse running determination means 210 determines that the host vehicle is running backward, and the warning instruction means 214 notifies the display control means 212. The display device 14 displays a reverse running warning message indicating that there is a possibility of reverse running (S509), and a reverse running alarm indicating that there is a possibility of reverse running is displayed on the alarm device. 18 (S510), and the process is terminated. On the other hand, when the distance between the current position and the previous position is less than the predetermined value in step S508 (S508, No), the process is terminated as it is. Since other steps S501 to S507 shown in FIG. 9 are the same as steps S101 to S107 shown in FIG. 5, the description of FIG.

  In addition, in this embodiment and its modification, although the whole navigation system 1 was described as what is mounted in a vehicle, you may implement | achieve some structural requirements with the server etc. which were installed outside the vehicle. For example, the map information storage unit 12, the map matching processing unit 208 of the processing device 20, and the reverse running determination unit 210 are realized by a server installed outside the vehicle, and the processing device 20 installed in the vehicle other than the above As each component (INS positioning unit 202, GPS positioning unit 204, display control unit 212, and warning instruction unit 214), the server and the processing device 20 can be connected by wireless communication or the like. .

  As described above, the navigation system 1 according to the present invention repeatedly specifies the host vehicle position on the road based on the map matching method, and the reverse running determination unit 210 determines the time for the host vehicle position repeatedly specified. Continuity, for example, relevance between roads including repeatedly identified vehicle positions (connectivity between roads and consistency of attributes), and continuity of distance between consecutively identified vehicle positions Etc., and reverse running of the host vehicle is detected based on the result of the evaluation. For this reason, the navigation system 1 applies the normal map matching method as it is, without losing the accuracy of specifying the position of the own vehicle, and without using a special database for reverse running detection. Run can be detected properly.

  DESCRIPTION OF SYMBOLS 1 ... Navigation system, 10 ... Location information detection part, 12 ... Map information storage part, 14 ... Display apparatus, 16 ... Input device, 18 ... Alarm apparatus, 20 ... Processing unit 102 ... Gyro sensor 104 ... Speed sensor 106 ... Acceleration sensor 108 ... GPS receiver 110 ... ETC on-board unit 112 ... Beacon receiver 202 .. INS positioning means, 204... GPS positioning means, 206... Position detecting means, 208... Map matching processing means, 210. ..Warning instruction means

Claims (1)

A storage device for storing map information including road map, a position detector for detecting the position of a vehicle, the said position detection means the predetermined ago repeatedly detected at intervals Symbol position location and the storage device stores a navigation system and a map matching processing means you perform map matching processing based on the map information,
The map matching process is a position on the road having the current travel direction as a travelable direction based on the current travel direction of the vehicle and the position detected by the position detection unit this time. A position closest to the position is specified as the current position of the vehicle,
Whether the vehicle has decelerated when the distance between the vehicle position specified this time by the map matching process and the vehicle position previously specified by the map matching process is equal to or greater than a predetermined value. Regardless, the vehicle is configured to determine that the vehicle is running backward with respect to the travelable direction of the currently traveling road.
Navigation system.

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