JP2011053004A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation device capable of enhancing the reliability of an estimated necessary time for arriving at a destination. <P>SOLUTION: The navigation device 1 calculates an estimated necessary time from its current position to the destination, and displays an estimated time of arrival based on the estimated necessary time on a display part 21. When the estimated time of arrival is calculated, the reliability of the estimated time of arrival is calculated. On the occasion of calculating the reliability, a main route and a spare route are acquired, and a travel time by the main route and a travel time by the spare route are compared. Moreover, a correlation coefficient between the change in traffic conditions of the main route and that of the spare route is acquired. In this case, when the difference between the travel time by the main route and the travel time by the spare route is not larger than a predetermined value, the reliability of the estimated time of arrival is calculated so as to be higher, as the correlation coefficient between the changes in traffic conditions is smaller. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a navigation device, and more particularly, to a navigation device that calculates an estimated required time to reach a destination and displays the reliability of the estimated required time.

  As a navigation device, there is known a navigation device that searches for a route from a departure point to a destination and provides guidance when the user sets the destination. Conventionally, as this type of navigation device, there is known a navigation device that searches for a recommended route to a destination, calculates an estimated required time required to travel along the recommended route, and displays the estimated required time on a display device such as a monitor. (For example, refer to Patent Document 1).

  In this navigation apparatus, past estimated required time is stored, and when calculating the estimated required time, the reliability for the estimated required time is calculated based on statistical information using the stored estimated required time. Furthermore, the reliability calculated here is displayed on the display device together with the estimated required time.

JP 2004-69609 A

  However, the navigation device in Patent Document 1 displays an estimated required time when the recommended route is advanced. For this reason, for example, when there are a plurality of routes to the destination, the required time may change significantly by traveling along routes other than the recommended route. Therefore, the estimated required time when the recommended route is advanced may differ greatly from the actual required time, and there is a problem that the reliability for the estimated required time cannot be made high.

  Accordingly, an object of the present invention is to provide a navigation device that can increase the reliability of the estimated required time to the destination.

  The navigation apparatus according to the present invention that has solved the above problems includes an estimated required time calculating means for calculating an estimated required time from a predetermined position to a destination, a reliability calculating means for calculating a reliability for the estimated required time, a destination A first route acquisition unit that acquires a first route that is a route up to, a second route acquisition unit that acquires a second route that is a route to a destination different from the first route, and when the first route is passed Travel time calculating means for calculating a first travel time that is a travel time from the predetermined position to a destination and a second travel time that is a travel time from the predetermined position to the destination when passing through the second route; Correlation coefficient acquisition means for acquiring a correlation coefficient of a traffic situation change between the first route and the second route, and the reliability calculation means has a predetermined difference between the first travel time and the second travel time. If it is less than or equal to the value, the correlation coefficient And it calculates the high reliability of the smaller estimated time.

  In the navigation device according to the present invention, in addition to the first route that is the route to the destination, the second route that is the route to the destination different from the first route is acquired. When the difference between the first travel time and the second travel time is less than or equal to a predetermined value, the reliability of the estimated required time is higher as the correlation coefficient of the traffic situation change between the first route and the second route is smaller. By calculating, the reliability of the estimated required time to the destination can be made high.

  Here, further comprising a deviation rate calculating means for calculating a deviation rate between the first travel time and the actual travel time on the first route, and the reliability calculating means, when the deviation rate exceeds a predetermined threshold, When the difference between the first travel time and the second travel time is equal to or smaller than a predetermined value, it is possible to calculate that the reliability of the estimated required time is higher as the correlation coefficient is smaller.

  When the deviation rate between the first travel time and the actual travel time is large, a high reliability of the estimated required time is often required. For this reason, when the deviation rate exceeds a predetermined threshold, if the difference between the first travel time and the second travel time is less than or equal to a predetermined value, the reliability of the estimated required time is higher as the correlation coefficient is smaller. Thus, even when the deviation rate between the first travel time and the actual travel time is large, the reliability of the estimated required time to the destination can be made high.

  According to the navigation device of the present invention, the reliability of the estimated required time to the destination can be made high.

It is a block block diagram of the navigation apparatus which concerns on embodiment of this invention. It is a flowchart which shows the process sequence in a navigation apparatus. It is explanatory drawing which shows the example of this path | route and a backup path | route. (A) is a figure which shows the monitor which displayed the estimated arrival time, (b) is a figure of the monitor which displayed reliability distribution.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a block diagram of a navigation device according to an embodiment of the present invention. As shown in FIG. 1, the navigation device 1 according to this embodiment includes a GPS (Global Positioning System) device 11, a wireless communication unit 12, and a route search unit 13. In addition, the navigation device 1 includes a travel time calculation unit 14, an estimated arrival time calculation unit 15, and a preliminary route recognition unit 16. The navigation device 1 further includes a deviation rate acquisition unit 17, a correlation coefficient calculation unit 18, and a preliminary route authorization unit 19. And the navigation apparatus 1 is provided with the reliability calculation part 20, the display part 21, and the antenna 22 for radio | wireless communication. The navigation device 1 can wirelessly communicate with the information management center 2 through the antenna 22.

  The navigation device 1 is mounted on a vehicle, for example, and various switches for operating the navigation device 1 are provided at positions where a vehicle occupant, for example, a driver can operate. Here, the destination setting in the navigation device 1 can be performed by a switch operation of the destination setting by the occupant.

  The information management center 2 acquires various types of information including the actual travel time of the vehicle, traffic information, and further traffic status change information through communication with a plurality of vehicles and other information sources. The information management center 2 calculates the deviation rate between the actual travel time and the traffic information for each link. It stores the divergence rate and traffic change for each link. Further, when the information management center 2 receives the current position information and the destination information transmitted from the navigation device 1, the information management center 2 indicates the divergence rate between the link from the current position to the destination and the traffic situation change. Send to.

  The GPS device 11 receives a GPS signal transmitted from a GPS satellite at regular intervals by a GPS receiver, demodulates the received GPS signal, and then performs a predetermined calculation process to detect the current position of the host vehicle. . The GPS device 11 outputs the detected current position of the host vehicle to the wireless communication unit 12.

  The wireless communication unit 12 can transmit and receive wirelessly with the information management center 2. The wireless communication unit 12 transmits the destination set by the destination setting switch operation and the current position of the vehicle output from the GPS device 11 to the information management center 2 via the antenna 22. Further, when passing between the links, the time when the links are passed and the actual travel time required when passing between the links are transmitted to the information management center 2.

  On the other hand, after transmitting the destination and current position to the information management center 2, the wireless communication unit 12, the rate of divergence between the link between the destination and the current position transmitted from the information management center 2 and the traffic situation change Receive. Further, the wireless communication unit 12 outputs the current position output from the GPS device 11 and the destination set by the destination setting switch operation to the route search unit 13 and the deviation rate acquisition unit 17, and the information management center 2. The divergence rate between links transmitted from is output to the divergence rate acquisition unit 17. Further, the wireless communication unit 12 outputs the received traffic condition change between links to the correlation coefficient calculation unit 18.

  The route search unit 13 searches for a route from the current position to the destination based on the current position and the destination output from the wireless communication unit 12. In searching for a route, the route search unit 13 searches for the main route as the first route and also searches for a backup route candidate serving as a plurality of backup routes as the second route.

  The route search unit 13 uses, as the main route, a route that takes into consideration the route that has the shortest distance from the starting point to the destination, the ease of driving when the vehicle travels on the traveling road, the degree of safety, and the like. Search by technique. In addition, as a backup route, for example, a backup route point such as an intersection is calculated between the departure point and the destination, and a backup route calculation point or a route from each backup route calculation point to the destination is calculated. Let it be a route candidate. At this time, a route connecting two nodes serving as backup route calculation points is calculated as a backup route candidate. When the backup route candidate is calculated, a main route corresponding to the backup route candidate (hereinafter referred to as “corresponding node main route”) is calculated. The route search unit 13 outputs the searched main route and the corresponding inter-node main route to the travel time calculation unit 14 and the deviation rate acquisition unit 17. The calculated preliminary route candidate is output to the travel time calculation unit 14.

  The travel time calculation unit 14 calculates a travel time to the destination when the vehicle travels on the main route output from the route search unit 13 (hereinafter referred to as “main route travel time”). Similarly, the travel time to the destination when the vehicle travels along the corresponding inter-node main route (hereinafter referred to as “corresponding inter-node main route travel time”) is calculated. Further, the travel time to the destination when the vehicle travels on each of the backup route candidates output from the route search unit 13 (hereinafter referred to as “backup route candidate travel time”) is calculated. The travel time calculation unit 14 outputs the calculated main route travel time to the estimated arrival time calculation unit 15. Further, the calculated main route travel time, the corresponding inter-node main route travel time and the preliminary route candidate travel time are output to the preliminary route recognition unit 16.

  The estimated arrival time calculation unit 15 has a clock function that recognizes the current time. The estimated arrival time calculation unit 15 calculates an estimated required time to the destination from the main route travel time output from the travel time calculation unit 14, and calculates the estimated required time and the current time recognized based on the clock function. The estimated arrival time is calculated from The estimated arrival time calculation unit 15 outputs the calculated estimated arrival time to the display unit 21.

  The preliminary route recognition unit 16 compares the plurality of preliminary route candidate travel times output from the travel time calculation unit 14 with the corresponding inter-node main route travel times, and obtains the difference therebetween. The spare route recognition unit 16 authorizes a spare route candidate whose spare route candidate travel time is close to the corresponding inter-node main route travel time as a spare route. The backup route certification unit 16 outputs the certified backup route and the corresponding inter-node main route corresponding to the backup route to the deviation rate acquisition unit 17 and the correlation coefficient calculation unit 18.

  The divergence rate acquisition unit 17 applies the divergence rate output from the wireless communication unit 12 to the corresponding inter-node main path output from the backup path authorization unit 16, and acquires the divergence rate in the corresponding inter-node main path. The deviation rate acquisition unit 17 outputs the acquired deviation rate of the route to the reliability calculation unit 20.

  The correlation coefficient calculation unit 18 applies the traffic change information output from the wireless communication unit 12 to the backup route and the corresponding inter-node main route output from the backup route recognition unit, respectively. The correlation coefficient is calculated. The correlation coefficient calculation unit 18 adds information regarding the correlation coefficient with the corresponding inter-node main path to the backup path and outputs the information to the backup path authorization unit 19.

  The spare route recognition unit 19 authorizes the spare route based on the spare route output from the correlation coefficient calculation unit 18 and the added correlation coefficient. When the spare route recognition unit 19 recognizes the spare route, the certified spare route and the correlation coefficient added to the spare route are output to the reliability calculation unit 20.

  The reliability calculation unit 20 calculates the reliability of the main route by using the correlation coefficient added to the main route output from the main route certification unit 19. The reliability calculation unit 20 refers to the deviation rate output from the deviation rate acquisition unit 17 when calculating the reliability of the route. The reliability calculation unit 20 outputs the calculated reliability of the main route to the display unit 21.

  The display part 21 is comprised by the monitor which consists of a touch panel provided in the vehicle interior, for example. The display unit 21 displays a map around the vehicle. The display unit 21 displays or can display the current position, the set destination, and the like. Further, the display unit 21 displays the route corresponding to the main route output from the route search unit 13, the estimated arrival time output from the estimated arrival time calculation unit 15, and the reliability output from the reliability calculation unit 20. Is displayed.

  Next, a processing procedure in the navigation device 1 according to the present embodiment will be described. FIG. 2 is a flowchart showing a processing procedure in the navigation device.

  In the navigation device 1, as shown in FIG. 2, first, a destination is set by a driver's operation (S1). In addition, while the processing in the navigation device 1 is being performed, the information management center 2 acquires the actual travel time, traffic information, and traffic status changes from the vehicle and other information sources. At the same time, the information management center 2 calculates the divergence rate for each link from the acquired traffic information and the actual travel time, and stores it at any time.

  When calculating the deviation rate, the deviation rate between the traffic information and the actual travel time is calculated for each link between the nodes based on the past traffic information. As a method for calculating the divergence rate, traffic information indicating that a certain link can be passed in 356 sec is received, but data that it took 795 sec when accumulating actually is accumulated. The deviation rate is calculated using the data accumulated here.

  Returning to the navigation device 1, when the destination is set, the route search unit 13 searches for the main route between the current position and the destination (S2). Subsequently, a spare route calculation point (node) is calculated for the searched main route (S3). The backup route calculation point can be determined as appropriate. The spare route calculation point can be, for example, for each intersection where a right / left turn occurs or for each intersection.

  When the backup route calculation point is calculated, the backup route is recognized (S4). At the time of recognition of the backup route, a plurality of backup route candidates are calculated by connecting the backup route calculation points. For the preliminary route candidates calculated here, the preliminary route candidate travel time is calculated in the travel time calculation unit 14. Furthermore, the travel time calculation unit 14 calculates the main route travel time for each node for the main route. Then, the backup route authorization unit 16 compares the backup route candidate travel time of each backup route candidate with the corresponding inter-node main route travel time, and the preliminary route candidate time is close to the corresponding inter-node main route travel time. Recognizes a backup route candidate having a difference of 3% or less from the corresponding route travel time as a backup route. Further, the travel time of the route recognized as the backup route is set as the backup route travel time.

  For example, in FIG. 3, it is assumed that a main route TR indicated by a solid line is searched between the current position S and the destination G. In this example, four preliminary route calculation points CP1 to CP4 are calculated for this route TR. A spare route candidate is calculated by connecting the current route S and the destination G to these spare route calculation points CP1 to CP4.

  Here, a search is made between the first backup route calculation point CP1 and the second backup route calculation point CP2. As a result, it is assumed that two backup route candidates PR1 and PR2 are searched between the first backup route calculation point CP1 and the second backup route calculation point CP2. At this time, the corresponding inter-node main route travel time between the first backup route calculation point CP1 and the second backup route calculation point CP2 is 3879 sec, and the first backup route travel time which is the travel time in the first backup route candidate PR1. Is 3950 sec, and the second preliminary route travel time, which is the travel time in the second preliminary route candidate PR2, is 3857 sec. In this case, the first preliminary route travel time and the second preliminary route travel time are within 3% of the travel time of the corresponding inter-node main route. Therefore, the first backup route candidate PR1 and the second backup route candidate PR2 are recognized as the first backup route and the second backup route, respectively.

  After the recognition of the backup path, the correlation coefficient calculation unit 18 calculates a correlation coefficient with the corresponding inter-node main path in each backup path (S5). The correlation coefficient is calculated for all routes that are recognized as backup routes. For the calculation of the correlation coefficient, a traffic situation change between the corresponding inter-node main route and the backup route output from the wireless communication unit 12 is used. The correlation coefficient calculation unit 18 compares the traffic situation change between the corresponding inter-node main route and the backup route, and calculates the correlation coefficient between the corresponding inter-node main route in the backup route. In the example shown in FIG. 3, the correlation coefficient for the corresponding inter-node main path in the first backup path PR1 is 0.93. Further, the correlation coefficient for the corresponding inter-node main path in the second backup path PR2 is 0.18.

  After the calculation of the correlation coefficient, the deviation rate acquisition unit 17 acquires the deviation rate (S6). When acquiring the divergence rate, the divergence rate acquisition unit 17 applies the divergence rate output from the wireless communication unit 12 to the corresponding inter-node main path output from the backup path authorization unit 16, and the divergence rate in the corresponding inter-node main path To get.

  When the deviation rate is acquired, the reliability and the swing width are calculated (S7). In calculating the reliability, first, the reliability is calculated when the deviation rate acquired in step S6 is high, for example, 1.0 or more. The preliminary route certification unit 19 authorizes the preliminary route from the spare routes certified by the backup route certification unit 16. In identifying the backup route, the correlation coefficient between the corresponding inter-node main route and the backup route is referred to, and a backup route having a low correlation coefficient, for example, a predetermined value of 0.3 or less is selected as the backup route. Authorize as.

  When the backup route is recognized, the reliability is obtained by the following equation (1) based on the correlation coefficient of the backup route.

  (Reliability [%]) = (1− (correlation coefficient) ÷ 2) × 100 [%] (1)

  In the example shown in FIG. 3, the correlation coefficient for the corresponding inter-node main path in the first backup path PR1 is 0.93, and the correlation coefficient for the corresponding inter-node main path in the second backup path PR2 is 0.18. . For this reason, the first backup route PR1 is not certified as the main backup route, and the second backup route PR2 is certified as the main backup route.

  After calculating the reliability, the runout is calculated. The swing width is obtained by the difference between the corresponding route travel time between the corresponding nodes and the spare route travel time of the spare route recognized as the spare route. In the example shown in FIG. 3, the corresponding inter-node main route travel time is 3879 sec, and the preparatory route travel time of the second preliminary route PR2 recognized as the main pre-route is 3857 sec. Therefore, the difference between the corresponding inter-node main route travel time and the backup route travel time of the second backup route PR2 is calculated, and the fluctuation width is calculated as 22 sec.

  In this way, after calculating the reliability and the fluctuation width between the nodes, it is determined whether or not there remains a node for which the reliability and the fluctuation width are not calculated for the backup path between the nodes (S8). As a result, if there remains a node between the nodes whose reliability and amplitude are not calculated, the process returns to step S5, and the reliability and amplitude are calculated for the backup path between the nodes by performing the same processing. .

  Then, when it is determined that there is no remaining node between which the reliability and the amplitude are not calculated, the reliability and the amplitude of the entire route are calculated (S9). The reliability of the entire route can be determined by, for example, an average value of reliability between nodes, an average value such as a multiplication average value, or other methods. Further, the shake width can be obtained as an average value of these values, or can be the total number of shake widths between the nodes.

  When the route from the current position to the destination, the estimated arrival time to the destination, and the reliability and fluctuation of the estimated arrival time are obtained in this way, display on the monitor which is the display unit 21 is performed (S10). When performing display on the monitor, as shown in FIG. 4A, a map around the position where the vehicle travels is displayed on the monitor. In the lower left corner of the monitor M, an estimated arrival time calculated by the estimated arrival time calculation unit 15 is displayed. The estimated arrival time shown in FIG. 4 (a) is 20: 9.

  Further, in the lower left corner of the monitor M, the reliability of the estimated arrival time is displayed. In the example shown in FIG. 4A, the reliability is 77%. This monitor M is a touch panel type, and as shown in FIG. 4A, when the lower left corner where the estimated arrival time is displayed is touched with a finger F, as shown in FIG. Instead, the reliability distribution O of the estimated arrival time is displayed. The reliability distribution O of the predicted arrival time is calculated based on the predicted arrival time reliability calculated by the reliability calculation unit 20, the fluctuation width, and the like.

  In the example shown in FIG. 4B, the time when the reliability of the estimated arrival time is the highest is 20: 9, and the reliability is displayed as 77%. In addition, “19:57” “20: 0” “20: 3” “20: 6” “20:12” “20:15” “20:18” “ At 20:21 ", the reliability of each estimated arrival time is displayed as a graph. When the display on the monitor is thus performed, the processing by the navigation device 1 is terminated.

  For example, if the traffic situation on the main route changes unexpectedly, the traffic situation on the backup route may change due to the change in the traffic situation on the main route. Thus, if the traffic situation of the backup route changes with the main route, the estimated arrival time changes significantly. For this reason, if the reliability of the estimated arrival time is calculated based only on the traffic situation of this route, if an accident or the like occurs on this route, the estimated arrival time and the actual arrival time will be greatly different.

  In this regard, in the navigation device 1 according to the present embodiment, the correlation coefficient between the main route and the backup route is calculated, and the reliability of the estimated arrival time is calculated using the correlation coefficient. Furthermore, the smaller the correlation coefficient, the higher the reliability of the estimated arrival time. For this reason, when the correlation coefficient of the backup route is low, even if an accident or the like occurs on the main route and the traffic situation changes greatly, the change of the traffic situation does not change significantly on the backup route. Therefore, by traveling along the preliminary route, it is possible to arrive at the destination in a time close to the time when traveling on this route, and the reliability of the estimated arrival time can be made high. Therefore, the difference in estimated arrival time can be reduced.

  In the navigation device 1 according to the present embodiment, the reliability of the estimated arrival time is calculated when the deviation rate is high. When the deviation rate is high, the travel time of this route and the actual travel time are often greatly different, and the estimated arrival time is often inaccurate. For this reason, when the divergence rate is high, calculating the reliability of the estimated arrival time is likely to cause inaccuracy of the estimated arrival time. Calculations can be made.

  Furthermore, in the navigation device 1 according to the present embodiment, the calculated reliability is displayed on the monitor, and the time estimated as the arrival time can be displayed on the monitor. For this reason, the driver using the navigation device 1 can determine whether or not the expected arrival time is trusted. Therefore, for example, for the meeting time at the destination, it is also possible to transmit the contents such as “it can arrive at this time at the latest” to the meeting partner. Further, as shown in FIG. 4B, the expected arrival time is displayed on the monitor M as a graph, thereby making it easy to make a future action plan.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the reliability is calculated when the deviation rate is high. However, the reliability may be calculated regardless of the deviation rate. Further, when calculating the reliability, the reliability can also be calculated by calculation using the deviation rate. In this case, the lower the deviation rate, the higher the reliability. Furthermore, when the deviation rate is higher than a predetermined threshold, the reliability can be obtained such that the lower the deviation rate, the higher the reliability.

  Further, in the above embodiment, when calculating the reliability, the above equation (1) is used, but it can also be obtained by other arithmetic expressions. Furthermore, in the above embodiment, an example in which there is only one backup path is described. However, when there are a plurality of backup paths, the reliability can be calculated using a plurality of backup paths. .

  Alternatively, even when a plurality of the backup paths are recognized, a backup path with the lowest correlation coefficient can be recognized as the backup path. In the above embodiment, only the backup route having a low correlation coefficient with respect to the main route is used as the main backup route. However, all recognized backup routes may be used as the main backup route. Furthermore, in the above-described embodiment, the shake width is obtained in addition to the reliability. However, only the reliability can be calculated without obtaining the shake width.

  On the other hand, in the above embodiment, the predetermined position is the current position. However, the present position is not limited to the current position, and an arbitrary position designated by the driver can be the predetermined position. Moreover, in the said embodiment, although the navigation apparatus 1 is vehicle-mounted, it may be mounted in moving bodies other than a vehicle, Furthermore, a pedestrian etc. may hold | maintain and it is at home etc. It may be fixed.

DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus, 2 ... Information management center, 11 ... GPS apparatus, 12 ... Wireless communication part, 13 ... Path | route search part, 14 ... Travel time calculation part, 15 ... Expected arrival time calculation part, 16 ... Preliminary route recognition part, DESCRIPTION OF SYMBOLS 17 ... Deviation rate acquisition part, 18 ... Correlation coefficient calculation part, 19 ... This preliminary path | route authorization part, 20 ... Reliability calculation part, 21 ... Display part, 22 ... Antenna.

Claims (2)

An estimated required time calculating means for calculating an estimated required time from a predetermined position to the destination;
Reliability calculation means for calculating the reliability for the estimated required time;
First route acquisition means for acquiring a first route that is a route to the destination;
Second route acquisition means for acquiring a second route that is a route to the destination different from the first route;
A first travel time that is a travel time from a predetermined position to the destination when passing through the first route, and a second travel time that is a travel time from the predetermined position to the destination when passing through the second route; Travel time calculating means for calculating;
Correlation coefficient acquisition means for acquiring a correlation coefficient of a traffic situation change between the first route and the second route;
With
When the difference between the first travel time and the second travel time is less than or equal to a predetermined value, the reliability calculation means calculates that the reliability of the estimated required time is higher as the correlation coefficient is smaller. A featured navigation device. A deviation rate calculating means for calculating a deviation rate between the first travel time and the actual travel time in the first route;
When the deviation rate exceeds a predetermined threshold and the difference between the first travel time and the second travel time is equal to or less than a predetermined value, the reliability calculation means determines that the correlation coefficient is smaller. The navigation device according to claim 1, wherein the navigation apparatus calculates that the estimated required time has high reliability.

Images