JP4728095B2 - Navigation device - Google Patents

Description

  The present invention relates to a navigation device, and more particularly to a technique for calculating a current position and a traveling direction of a navigation device.

  Patent Document 1 discloses a navigation device that obtains the current position and traveling direction of a traveling vehicle. The navigation apparatus periodically calculates a new current position and traveling azimuth by adding the relative displacement obtained using the vehicle speed sensor and the azimuth sensor to the current position and traveling azimuth adopted last time (dead reckoning). processing). Also, periodically, if the correlation between the newly adopted current position and traveling direction and the road indicated by the map data is equal to or greater than a predetermined value, the newly adopted current position and traveling direction are displayed on the road. (Map match processing). By this map matching process, the current position displayed on the display device is periodically corrected so as to be located on the road of the map data.

  Patent Document 2 discloses a navigation device that obtains the current position and traveling direction of a vehicle using GPS data. The navigation device periodically acquires GPS data from a GPS receiver. If it is determined that the current position and traveling direction are determined from the GPS data, the current position and traveling direction obtained from the GPS data are adopted, and the adopted current position and traveling direction are determined as map data. And display it on the display device.

JP-A-8-334349 JP 2005-156246 A

  When the navigation device technology described in Patent Literature 2 is applied to the navigation device described in Patent Literature 1 and it is determined that the current position and traveling direction accuracy (accuracy) obtained from GPS data is high, dead reckoning It is conceivable to adopt the current position and traveling direction obtained from the GPS data instead of the current position and traveling direction of the vehicle obtained by the processing.

  By the way, the map match process does not perform a correction to align the current position and traveling direction of the vehicle on the road when the correlation between the current position and traveling direction of the vehicle and the position and direction of the road indicated by the map data is small. . Therefore, for example, when a vehicle is present in a multilevel parking lot where the GPS receiver cannot receive a GPS signal and the location is away from the road, the current position and traveling direction obtained from the GPS data are In addition, the map match process is not performed, and as a result, the current position and traveling direction of the vehicle calculated by the dead reckoning process may continue to be employed.

  In this case, errors of the vehicle speed sensor and the direction sensor are accumulated in the current position and traveling direction of the vehicle. If the vehicle moves from a multilevel parking lot or the like to a road with errors accumulated in the current position and traveling direction of the vehicle, the correlation with a road that is different from the road that is actually running may increase. If the map matching process is performed in this state, the current position and traveling direction of the vehicle in which the error is accumulated are adjusted to the wrong road. In this case, the current position and traveling direction of the vehicle obtained from the GPS data are adopted, and then the current position is displayed on the wrong road until a new map matching process is performed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to display the current position of a vehicle on a correct road.

  In order to solve the above problems, the present invention provides a dead reckoning processing means for calculating a current position of a vehicle by dead reckoning processing, a vehicle current position calculated from the current position of the vehicle and GPS data calculated by the dead reckoning processing means. Selection means for selecting and outputting either one of the current positions, and a map for correcting the current position of the vehicle selected by the selection means by map matching processing using map data periodically or every time a predetermined distance is traveled Match processing means, and road data registration means for registering road data having a correlation with the current position selected by the selection means, wherein the map match processing means is a vehicle calculated by the dead reckoning processing means. When the current position is selected by the selection means for a predetermined number of times or for a predetermined period, the road data registration is performed. The map matching processing using road data registered by means performs modifying the current position of the vehicle in which the selection means selects.

  Further, the present invention adopts the current position and traveling direction obtained from the GPS data when it is determined that the accuracy (accuracy) of the current position and traveling direction obtained from the GPS data is higher than a predetermined reference value. When the vehicle is determined to be below the reference value, the vehicle's current position and travel direction determined by dead reckoning processing are adopted, and map match against the adopted current position and travel direction is performed periodically or every time a predetermined distance is traveled. In a navigation device that performs processing, when a vehicle enters an area where the current position and traveling direction of the vehicle calculated by dead reckoning processing can continue to be adopted (for example, a multi-story parking lot), the vehicle comes out of the area again. Information on roads that are likely to travel is registered in the table. When the vehicle escapes from the area, if the map match process is performed before the current position and traveling direction of the vehicle determined from the GPS data are adopted, the map registered on the table is displayed on the road. Make sure that it is matched preferentially.

For example, the present invention provides a navigation device that calculates a current position on a map using GPS data received by a mobile body and sensor data from a sensor mounted on the mobile body, and the sensor data is dead-ended. Means for performing reckoning processing, selecting means for selecting either the GPS data or the sensor data subjected to the dead reckoning processing, the direction and position included in the selected data, and the direction of the link on the map data If the current position is obtained on the link based on the map and the position, the obtained position is set as the display current position. If the current position is not obtained on the link, the selected position is selected. Map match processing means that uses the position included in the data as the current position for display, and the sensor data is selected by the selection means for a predetermined period. Means for detecting a candidate link around the current position for display when the position selected and included in the selected data is the current position for display; and means for storing the detected candidate link When the candidate link is stored, the map match processing means performs the map matching process on the candidate link.

  According to the present invention, the current position and traveling direction of the vehicle calculated by the dead reckoning process are continuously adopted, and even when errors are accumulated, the current position of the vehicle is displayed on the correct road. it can.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic diagram of an in-vehicle navigation system to which an embodiment of the present invention is applied. As illustrated, the in-vehicle navigation system of the present embodiment includes a navigation device 1, a GPS receiver 2, an in-vehicle sensor 3, an input device 4, and an output device 5.

  The GPS receiver 2 receives GPS signals transmitted from a plurality of GPS satellites, and uses these GPS signals for GPS data including current position information and satellite reception status information every predetermined time (for example, 1 second). And sequentially output to the navigation device 1. Here, the current position information includes the current position (latitude, longitude) and the traveling direction. The satellite reception status information includes DOP (Dilution of Precision) that is a GPS positioning accuracy degradation coefficient that is influenced by the geometrical arrangement of the satellite viewed from the reception point. The in-vehicle sensor 3 includes at least a vehicle speed sensor that measures the vehicle speed, an acceleration sensor that measures a change in the vehicle speed per unit time, and an orientation sensor that measures the traveling direction of the vehicle. The input device 4 includes an operation panel, a touch panel, and the like, receives an instruction from the operator, and transmits the instruction content to the navigation device 1. The output device 5 includes a display device and an audio output device. The display device is composed of, for example, a liquid crystal panel and displays a video signal (navigation screen) output from the navigation device 1. Note that existing devices can be used for the GPS receiver 2, the in-vehicle sensor 3, the input device 4, and the output device 5.

  The navigation device 1 detects the current position using data from the GPS receiver 2 and the vehicle-mounted sensor 3, and performs map display, route guidance, and the like around the current position using the detected current position. As shown in the figure, a map data storage unit 11 that stores map data, a current position measurement unit 12, a reliability determination unit 13, a selection unit 14, a map match processing unit 15, a navigation processing unit 16, and a map It has a match candidate road detection unit 17 and a map match candidate road storage unit 18.

  FIG. 2 is a diagram illustrating a configuration example of map data stored in the map data storage unit 11. As shown in the drawing, map data 21 is stored for each mesh region obtained by dividing a map into a plurality of parts. The map data 21 has an entry 211 for registering an identification code (mesh ID) of the mesh area and an entry 212 for registering link data of each link constituting the road included in the mesh area. The entry 212 includes a sub-entry 2121 for registering a link identification code (link ID), a sub-entry 2122 for registering a time required for traveling the link, and a sub-entity for registering link length information indicating the length of the link. The entry 2123, the sub-entry 2124 for registering the coordinate information (start node coordinates) of the start node of the two nodes constituting the link and the link ID (adjacent link ID) of the link connected to the start node, constitute the link Of the two nodes, sub-entry 2125 for registering the coordinate information (end node coordinates) of the end node and the link ID (adjacent link ID) of the link connected to the end node, and the sub-entry for registering the regulation information of the road including the link 2126.

  In addition to the above map data, the map data storage unit 11 stores a conversion table for specifying a mesh ID of a mesh region including a point specified by the current position information from the current position information. .

  The map match candidate road storage unit 18 stores information on links that preferentially match the current position and the traveling direction in a link list priority process performed by the map match processing unit 15 described later.

  FIG. 3 is a diagram illustrating a configuration of the map match candidate road storage unit 18. As shown in the figure, a record 30 is registered for each link that preferentially matches the current position in a link list priority process described later. The record 30 has a field 31 for registering the link priority, a field 32 for registering the link ID of the link, and a field 33 for registering the cost of the link. In the link list priority process, the top several links with higher priority are selected as the links to which the current position is adjusted. The cost is set so that the link having a higher correlation with the current position of the traveling vehicle has a lower value in a state where the current position and traveling direction of the vehicle are not aligned with the link (so-called free state). In the present embodiment, in the free state, the sum of the distances of the perpendiculars that are sequentially calculated from each current position of the vehicle to the link is calculated for each link, and the sum is set as the cost of the link. The priority order is set so that the lower the cost, the higher the priority.

  Returning to FIG. 1, the description will be continued. The current position measuring unit 12 receives the sensor value data sequentially output from the in-vehicle sensor 3, and the current position and progress of the previous adoption (output to the navigation processing unit 16) sequentially output from the map match processing unit 15. Receive azimuth data. In addition, the local position measuring unit 12 receives the current position and progress of the previous adoption received from the map match processing unit 15 every time the travel distance obtained from the vehicle speed sensor value received from the in-vehicle sensor 3 reaches a predetermined distance (for example, 2 m). A dead reckoning process for calculating a new current position and traveling direction is performed by adding the relative displacement obtained using the vehicle speed sensor value, the acceleration sensor value, and the direction sensor value received from the in-vehicle sensor 3 to the direction data. . Then, the newly calculated current position and traveling direction data are output to the selection unit 14.

  The reliability determination unit 13 receives GPS data sequentially output from the GPS receiver 2. In addition, the reliability determination unit 13 calculates the reliability using the DOP value included in the GPS data. Then, the data of the calculated reliability is added to the data of the current position and traveling direction of the vehicle obtained from the GPS data, and output to the selection unit 14. Specifically, the reliability determination unit 13 calculates the reciprocal of the DOP value, adds the calculated value as the reliability, and adds the reliability to the current position and travel direction data obtained from the GPS data. To the unit 14. Since the value of DOP and the value of RMS (Root Mean Square), which is an index indicating the positioning error of GPS, are in a proportional relationship, if the reciprocal of the value of DOP is used as the reliability, the greater the reliability, the more GPS The positioning error of is small, and the positioning error of GPS increases as the reliability decreases.

  The selection unit 14 receives the current position and travel direction data with reliability output from the reliability determination unit 13 and the current position and travel direction data output from the current position measurement unit 12. Further, each time the selection unit 14 receives the current position and traveling direction data output from the reliability determination unit 13, it is determined whether or not the reliability added to the data is greater than or equal to a predetermined reference value. Judgment is made, and when the reliability is equal to or higher than a predetermined reference value, the current position and traveling direction data output from the reliability determination unit 13 are selected. On the other hand, if the reliability is less than the predetermined reference value, the current position and traveling direction data output from the current position measuring unit 12 are selected. Then, a map matching process is performed by adding a selection result flag indicating whether the data is output from either the current position measurement unit 12 or the reliability determination unit 13 to the selected current position and traveling direction data. To the unit 15.

  The map match processing unit 15 receives the current position and traveling direction data with the selection result flag sequentially output from the selection unit 14. Further, the map match processing unit 15 uses the current position and traveling direction data with the selection result flag sequentially output from the selection unit 14 as adoption data, adds a map match processing flag to the data, and adds a navigation processing unit 16 and output to the current position measurement unit 12 and the map match candidate road detection unit 17. Here, the map match processing flag indicates whether or not the adopted data is data that has undergone map match processing, and if the data has been subjected to map match processing, the data is in a free state (the current position of the vehicle is on the road). It is data indicating whether or not it is in a state of not being adjusted to (1). In this case, a map match process flag indicating that the map match process is not performed is added to the adopted data.

  In addition, the map match processing unit 15 selects the selection unit 14 every time the travel distance obtained from the current position and travel direction data with the selection result flag sequentially output from the selection unit 14 reaches a predetermined distance (for example, 20 m). Between the current position and travel direction of the vehicle indicated by the current position and travel direction data with the latest selection result flag output from the road position and direction indicated by the map data stored in the map data storage unit 11 Check whether the relationship is greater than or equal to a predetermined value. If the correlation is greater than or equal to the predetermined value, the current position and travel direction data with the latest selection result flag is the road position and the position indicated by the map data stored in the map data storage unit 11. A process for matching the road direction of the road, that is, a map matching process is performed. Then, the map match processing flag indicating the current position and traveling direction data with the selection result flag that has been subjected to the map match processing is used as adopted data, indicating that the data has been subjected to the map match processing and whether or not it is in a free state Is output to the navigation processing unit 16, the current position measurement unit 12, and the map match candidate road detection unit 17.

  The map match processing unit 15 performs link list priority processing. Here, the link list priority processing will be described. The map match processing unit 15 receives the link list priority processing instruction from the map match candidate road detection unit 17 and before the first map match processing is performed, the current position and traveling direction output from the reliability determination unit 13 Is not output from the selection unit 14 to the map match processing unit 15 (that is, the current position and traveling direction data output from the current position measurement unit 12 is output from the selection unit 14 to the map match processing unit 15. In the case of continuing, a link list output by a map match candidate road detection unit 17 described later is obtained. Here, the link list describes at least one piece of link data of a link that preferentially matches the current position. The map match processing unit 15 is a vehicle indicated by the current position and travel direction data with the selection result flag output from the selection unit 14 for each link described in the obtained link list in the first map match processing. If there is a link with a correlation greater than or equal to a predetermined value, it is checked whether the correlation between the current position and travel direction of the link and the position and road direction indicated by the link data of each link is greater than or equal to a predetermined value. The data of the current position and traveling direction with the selection result flag is matched with the position on the link having the highest correlation among the links having the correlation more than the predetermined value and the road direction of the link at the position. Process.

  FIG. 4 is a diagram for explaining the processing flow of the map match processing unit 15.

  When the map match processing unit 15 receives the link list priority processing instruction from the map match candidate road detection unit 17 (YES in S401), the map match processing unit 15 determines from the map match candidate road detection unit 17 as a link that matches the current position and traveling direction of the vehicle. A priority flag (not shown) indicating that a link described in the output link list should be preferentially selected is set to ON (S402).

  Further, when the map match processing unit 15 receives the current position and travel direction data with the selection result flag from the selection unit 14 (YES in S403), the travel distance is based on the current position and travel direction data with the selection result flag. It is determined whether or not the measured value of a distance meter A (not shown) that measures the distance reaches a predetermined value (for example, 20 m) (S404).

  In S404, when it is determined that the measured value of the distance meter A has not reached the predetermined value (NO in S404), the map match processing unit 15 uses the data on the current position and the traveling direction with the selection result flag as adopted data. Then, a map match processing flag indicating that the map match processing has not been performed is added to the data, and the flag is output to the navigation processing unit 16, the current position measurement unit 12, and the map match candidate road detection unit 17 (S405). Then, based on the state indicated by the selection result flag added to the current position and travel direction data with the selection result flag, the map match processing unit 15 trusts the current position and travel direction data with the selection result flag. It is determined whether the data is output from the degree determining unit 13 or the data output from the current position measuring unit 12 (S406). If it is determined that the data is output from the current position measurement unit 12 (dead reckoning in S406), the process immediately returns to S401. On the other hand, if it is determined that the data is output from the reliability determination unit 13 (GPS in S406), if the priority flag is on (YES in S407), it is turned off (S408), and the process returns to S401. If the priority flag is off (NO in S407), the process immediately returns to S401.

  In S404, when it is determined that the measured value of the distance meter A has reached a predetermined value (YES in S404), the map match processing unit 15 is added to the data on the current position and traveling direction with the selection result flag. Based on the state indicated by the selection result flag, whether the current position and travel direction data with the selection result flag is the data output from the reliability determination unit 13 or the data output from the current position measurement unit 12 It is determined whether it exists (S409). If it is determined that the data is output from the reliability determination unit 13 (GPS in S409), the process proceeds to S413. On the other hand, if it is determined that the data is output from the current position measurement unit 12 (dead reckoning in S409), if the priority flag is off (NO in S410), the process proceeds to S413, and if the priority flag is on (in S410). YES), link list priority processing is performed (S411).

  Specifically, first, the map match processing unit 15 acquires link data having each link ID described in the link list from the map data storage unit 11. Then, the obtained link data is compared with the data of the current position and the traveling direction with the selection result flag, and the correlation (for example, the distance between the link and the vehicle, and the link direction and the traveling direction of the vehicle) Examine the difference. When there is a link having a correlation greater than or equal to a predetermined value, the data on the current position and the traveling direction with the selection result flag are matched with the link having the link data. Then, the combined data of the current position and the heading direction with the selection result flag is set as adopted data, and a map match processing flag indicating that the map match processing is not performed and the free state is not added is added to the data. When there are a plurality of links having a correlation greater than or equal to a predetermined value, the data on the current position with the selection result flag and the traveling direction are combined on the link having the highest correlation. On the other hand, if all of the links having the link IDs described in the link list have a correlation less than the predetermined value, the process proceeds to S412. Even if the link data has a link ID described in the link list, if the restriction information of the link data indicates that the road is closed, it should be excluded from the above-mentioned link list priority processing target. Also good.

  After the execution of the link list priority process (S411), the map match processing unit 15 can generate the adoption data by the link list priority process (the current position and travel direction data with the selection result flag are matched to the link). If YES in step S412 (YES in step S412), the process proceeds to step S414. On the other hand, if the adoption data could not be generated (when the correlation between the current position with the selection result flag and the data of the traveling direction is less than the predetermined value for all the links described in the link list) (S412). NO), the process proceeds to S413.

  In S413, the map match processing unit 15 performs map match processing on the road stored in the map data storage unit 11 as a link candidate for combining the current position and direction data with the selection result flag. Thereafter, the process proceeds to S414.

  Specifically, the map match processing unit 15 reads the conversion table from the map data storage unit 11 and uses the conversion table to include a mesh that includes the current position with the selection result flag and the position indicated by the data of the traveling direction. Specify the mesh ID of the region. Then, each link data registered in the map data 21 having the specified mesh ID is obtained from the map data storage unit 11. Next, the obtained link data is compared with the data on the current position and traveling direction with the selection result flag, and the correlation is examined in the same manner as in S411. When there is a link having a correlation greater than or equal to a predetermined value, the data on the current position and the traveling direction with the selection result flag are adjusted on the link. When there are a plurality of links having a correlation greater than or equal to a predetermined value, the data on the current position with the selection result flag and the traveling direction are combined on the link having the highest correlation. Then, the combined data of the current position and the heading direction with the selection result flag is set as adopted data, and a map match processing flag indicating that the map match processing is not performed and the free state is not added is added to the data. On the other hand, if there is no link data whose correlation is equal to or greater than the predetermined value, the data of the current position and the heading direction with the selection result flag is adopted data, the map match processing is performed on the data, and the free state The map match processing flag shown is added.

  In S414, the map match processing unit 15 outputs the adopted data to which the map match processing flag is added to the navigation processing unit 16, the current position measuring unit 12, and the map match candidate road detecting unit 17. Then, the measured value of the distance meter A is reset to 0 (S415), and the process proceeds to S416. Thereafter, when the priority flag is on (YES in S416), the map match processing unit 15 turns off the priority flag (S417), and then returns to S401. On the other hand, if the priority flag is off (NO in S416), the process immediately returns to S401.

  Returning to FIG. 1, the description will be continued. The navigation processing unit 16 reads out necessary map data from the map data storage unit 11 (for example, map data around the current position of the vehicle indicated by the adopted data with the map match processing flag output from the map match processing unit 15). It is displayed together with the current position and the traveling direction indicated by the adoption data with the map match processing flag output from the map match processing unit 15. Further, the information on the recommended route stored in the storage unit (not shown) is compared with the data on the current position and the traveling direction indicated by the adopted data with the map match processing flag output from the map match processing unit 15, and the intersection The user is informed of whether to go straight ahead or to turn left or right before passing the road, or the user is notified of the recommended route by displaying the direction to proceed on the displayed map.

  The map match candidate road detection unit 17 receives the adoption data with the map match processing flag output from the map match processing unit 15 (the current position and travel direction data with the selection result flag). In addition, the map match candidate road detection unit 17 cannot receive the GPS signal, for example, based on the selection result flag of the adopted data with the map match processing flag and the state indicated by the map match processing flag. Whether the vehicle has entered an area where the location is far from the road (such as a multilevel parking garage where the current position and traveling direction of the vehicle are unlikely to be adjusted on the road by map matching) Detect whether or not.

  Specifically, the selection result flag of the adopted data with the map match processing flag sequentially output from the map match processing unit 15 is continuously output a predetermined number of times indicating that the data is output from the current position measurement unit 12. Of the adopted data with map match processing flag sequentially output from the map match processing unit 15, the adopted data with map match processing flag to which the map match processing flag indicating that the map match processing has been added is When the map match processing flag indicates that it is in a free state continuously for a predetermined number of times, the GPS receiver 2 cannot receive GPS signals and the location is away from the road. Detect that a vehicle is entering.

  The map match candidate road detection unit 17 gives priority to the link list when the GPS receiver 2 cannot receive a GPS signal and detects that the vehicle has entered an area where the location is far from the road. A processing instruction is output to the map match processing unit 15, and information on a link that is likely to travel when the vehicle exits the area is registered in the map match candidate road storage unit 18. Further, information on links registered in the map match candidate road storage unit 18 using the adoption data with the map match processing flag output from the map match processing unit 15 while the vehicle is traveling in the area. Narrow down information on links that are more likely to travel when the vehicle exits the area. Then, a link list describing the narrowed-down link information is created and output to the map match processing unit 15. This process is continued until, for example, the GPS receiver 2 cannot receive a GPS signal and detects that the vehicle has escaped from an area where the location is far from the road.

  Specifically, the map match candidate road detection unit 17 receives from the map match processing unit 15 adoption data with a map match processing flag having a selection result flag indicating that the data is output from the reliability determination unit 13. Or, it continues until it receives from the map match processing unit 15 adoption data with a map match processing flag indicating that the map match processing has been performed and that it is not in the free state.

  FIG. 5 is a diagram for explaining the processing flow of the map match candidate road detection unit 17.

  First, the map match candidate road detection unit 17 is output from the reliability determination unit 13 in the adopted data with the map match processing flag output from the map match processing unit 15 while traveling for a predetermined period or a predetermined distance. It is determined whether or not there is data having a selection result flag indicating data (S501).

  When it is determined in S501 that there is no data having a selection result flag indicating that the data is output from the reliability determination unit 13 (NO in S501), the map match candidate road detection unit 17 performs a predetermined period or a predetermined distance. Whether or not there is data having a map match processing flag indicating that the map match processing has been performed and that there is no free state in the adopted data with the map match processing flag output from the map match processing unit 15 while traveling Is further determined (S502).

  If it is determined in S502 that there is data having a map match process flag indicating that the map match process has been performed and that the map is not in a free state (YES in S502), the process returns to S501. On the other hand, if it is determined that there is no such data (NO in S502), the map match candidate road detection unit 17 creates a link around the current position indicated by the adopted data with the map match processing flag newly output from the map match processing unit 15. Data is acquired from the map data storage unit 11 and registered in the map match candidate road storage unit 18 (S503).

  Specifically, the map match candidate road detection unit 17 reads the conversion table from the map data storage unit 11 and uses the conversion table to be included in the region including the current position indicated by the adopted data with the map match processing flag. The mesh ID of the mesh area is specified. Next, among the link data registered in the map data 21 having the identified mesh ID from the map data storage unit 11, the distance from the current position indicated by the adopted data with the map match processing flag is within a predetermined distance. The link data is obtained, and the record 30 is registered in the map match candidate road storage unit 18 for each obtained link data. Then, the link ID of the link data corresponding to the record 30 is registered in the field 32 of each registered record 30 (S503).

  Next, the map match candidate road detection unit 17 outputs a link list priority processing instruction to the map match processing unit 15 (S504). Thereafter, the measured value of a distance meter B (not shown) that measures the travel distance based on the adopted data with the map match processing flag is reset to 0 (S505).

  Next, the map match candidate road detection unit 17 acquires link data having the link ID registered in the field 32 of each record 30 registered in the map match candidate road storage unit 18 from the map data storage unit 11. To do. Then, a perpendicular distance from the current position of the adopted data with the map match processing flag is obtained for each acquired link data. Further, the record 30 in which the link ID of the link data is registered in the field 32 is searched from the map match candidate road storage unit 18. Then, the obtained perpendicular distance is added to the cost registered in the field 33 of the retrieved record 30 (S506).

  Next, the map match candidate road detection unit 17 sorts the records 30 registered in the map match candidate road storage unit 18 in ascending order of cost values registered in the field 33. Then, the priority order is determined in the sort order, and the determined priority order is registered in the field 31 of the corresponding record 30. Next, a link list in which several high-priority (for example, five) link IDs with higher priorities are described is generated, and this link list is output to the map match processing unit 15 (S507).

  Then, the map match candidate road detection unit 17 determines whether or not the measurement value of the distance meter B has reached a predetermined value (for example, 20 m) (S508), and if it has reached the predetermined value (YES in S508). , The process returns to S505. On the other hand, if not reached (NO in S508), the selection result flag of the adopted data with the map match processing flag output from the map match processing unit 15 is selected by the selection unit 14 as the data output from the reliability determination unit 13. It is determined whether or not it has been selected (S509). If it is determined that it has been selected (YES in S509), the registered content of the map match candidate road storage unit 18 is reset (S511), and then the process goes to S501. Return. On the other hand, if it is determined that it is not shown (NO in S509), it is determined whether or not the map match processing flag of the adopted data with the map match processing flag indicates that the map match processing has been performed and that it is not in a free state. Further determination is made (S510), and if it is shown (YES in S510), the registered content of the map match candidate road storage unit 18 is reset (S511), and then the process returns to S501. If not shown (NO in S510), the process returns to S508.

  The navigation device 1 configured as described above includes, for example, a CPU, a memory, an external storage device such as a ROM and an HDD, a reading device that reads information from a portable storage medium such as a CD-ROM and a DVD-ROM, In a computer having an input device, an output device, and a bus connecting these components, the CPU loads a predetermined program from a storage medium to a memory via an external storage device or a reading device and executes the program This can be achieved.

  The embodiment of the present invention has been described above.

  When it is determined that the accuracy (accuracy) of the current position and the traveling direction obtained from the GPS data is high, the current position and the traveling direction obtained from the GPS data are replaced with the current position and the traveling direction of the vehicle obtained by the dead reckoning process. In a navigation device that employs a traveling direction, the current position and progression of a vehicle calculated by a dead reckoning process in a parking lot where the GPS signal reception state of the GPS receiver is poor and the location is far from the road. The direction data continues to be adopted, and errors of the vehicle measurement sensor and the direction sensor are accumulated in the current position and traveling direction of the vehicle. For example, as shown in FIG. 6 (A), the vehicle enters the multilevel parking lot 64 from the point X, repeatedly turns in the multilevel parking lot 64, and travels toward Y after the multilevel parking lot 64 is released. In the case of performing the above, an error is accumulated in the data on the current position and traveling direction of the vehicle in the multi-story parking lot 64. After that, when the vehicle goes out on the road and the map matching process is performed, the map matching process is performed at an incorrect position and displayed on the display screen (61). Then, the current position and traveling direction data of the vehicle obtained from the GPS data are adopted, and then the current position of the vehicle is displayed on the wrong road until map matching is performed by the map matching process (62).

  On the other hand, according to the present embodiment, the current position and traveling direction data of the vehicle calculated by the dead reckoning process is continuously adopted, and errors are accumulated in the current position and traveling direction data of the vehicle. When the map match process is performed, the link data of the road where the vehicle is likely to travel is registered in the map match candidate road storage unit 18, and the link data registered in the map match candidate road storage unit 18 indicates Match preferentially on the road. For this reason, as shown in FIG. 6B, even if the vehicle comes out on the road and the map matching process is performed, the map is matched with the road on which the vehicle is actually traveling (63), and the vehicle actually The current position and traveling direction of the vehicle can be displayed on the road on which the vehicle is traveling.

  As described above, the present embodiment is particularly effective when the vehicle travels in a self-propelled multilevel parking lot having a structure in which the vehicle turns while the vehicle travels on the premises.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist.

  For example, in the above embodiment, the start timing of the cost calculation process performed by the map match candidate road detection unit 17 (S508 in FIG. 5) and the start timing of the map match process performed by the map match processing unit 15 (S404 in FIG. 4). Has been described for each predetermined distance traveled. However, the present invention is not limited to this. These activation timings may be set at regular intervals.

  In the above embodiment, an example in which the present invention is applied to an in-vehicle navigation device has been described. However, the present invention can also be applied to inventions other than in-vehicle use.

FIG. 1 is a schematic diagram of an in-vehicle navigation system to which an embodiment of the present invention is applied. FIG. 2 is a diagram showing a configuration example of map data stored in the map data storage unit 11 shown in FIG. FIG. 3 is a diagram showing a configuration of the map match candidate road storage unit 18 shown in FIG. FIG. 4 is a flowchart for explaining the processing of the map match processing unit 15 shown in FIG. FIG. 5 is a flowchart for explaining the processing of the map match candidate road detection unit 17 shown in FIG. FIG. 6 is a diagram for explaining the problem to be solved by the invention according to the embodiment and the effect of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus, 2 ... GPS receiver, 3 ... In-vehicle sensor, 4 ... Input device, 5 ... Output device, 11 ... Map data storage part, 12 ... Current position measurement part, 13 ... Reliability determination part, 14 ... Selection 15, a map match processing unit, 16 a navigation processing unit,
17 ... Map match candidate road detection unit, 18 ... Map match candidate road storage unit

Claims (4)

A navigation device that calculates a current position on a map using GPS data received by a mobile body and sensor data from a sensor mounted on the mobile body,
Means for dead reckoning the sensor data;
Selecting means for selecting either the GPS data or the sensor data subjected to the dead reckoning process;
Based on the azimuth and position included in the selected data and the azimuth and position of the link on the map data, the map matching process is performed, and when the current position is obtained on the link, it is obtained. If the position is the current position for display and is not found on the link, map match processing means that uses the position included in the selected data as the current position for display;
Means for detecting candidate links around the current position for display when the sensor data is selected by the selection means for a predetermined period and the position included in the selected data is the current position for display; ,
Means for storing the detected candidate link,
The navigation device according to claim 1, wherein, when the candidate link is stored, the map match processing means performs the map matching processing on the candidate link . The navigation device according to claim 1,
The map match processing means, when the candidate link is stored, when the map matching process is performed on the candidate link and the current position for display is not obtained,
A navigation device that performs map matching processing on a link on map data . The navigation device according to claim 1 or 2,
The means for detecting the candidate link is:
A cost value is added to each link information stored in the means for storing the candidate link, depending on the relationship between the azimuth and position of the moving object,
The map match processing means includes:
Performing a map matching process on a predetermined number of candidate links having a small cost value among the links stored in the means for storing the candidate links;
A navigation device characterized by the above. A navigation device is a method of calculating a current position on a map using GPS data received by a mobile body and sensor data from a sensor mounted on the mobile body,
Dead-reckoning the sensor data;
A selection step for selecting either the GPS data or the sensor data subjected to the dead reckoning process;
Based on the azimuth and position included in the selected data and the azimuth and position of the link on the map data, the map matching process is performed, and when the current position is obtained on the link, it is obtained. If the position is the current position for display and is not obtained on the link, a map match processing step in which the position included in the selected data is the current position for display;
A step of detecting candidate links around the display current position when the sensor data is selected by the selection step for a predetermined period and the position included in the selected data is the display current position; ,
Storing the detected candidate link,
When the candidate link is stored, the map match processing step performs the map matching process on the candidate link.
A method for calculating a current position characterized by.

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