JP2008032471A - Car navigation apparatus and return route setting method in same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy the desire to take a return route which is the same as an outward route and automatically set a return route with a shorter travel distance. <P>SOLUTION: An outward route from a starting point to a destination is stored. On arrival at the destination, a return route candidate is determined on the basis of predetermined conditions. When the return route candidate branches off from the outward route, a return route candidate leading to the starting point from the branch point is added to the predetermined conditions and is determined under the condition that it joins the outward route, thereby setting a return route leading to the starting point from the destination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a return route setting method and a car navigation device in a car navigation device that automatically sets a return route from an arrival point to a departure point when arriving at a destination.

A car navigation device usually has a travel route guidance function. When the destination is set, this travel route guidance function searches for a guide route from the departure point (usually the current location) to the destination. When the vehicle starts to travel, the direction of travel at an intersection or the like is determined by voice and an enlarged map. It is to guide you.
Some car navigation devices having such a travel route guidance function automatically set a return route from an arrival location to a departure location when the vehicle arrives at a destination (for example, Patent Document 1).
JP-A-10-281785

In the above-mentioned Patent Document 1, while traveling on the forward route from the starting point to the destination, the currently traveling road is recognized, the return route road corresponding to this road is acquired and stored as the return route data. Go. When the vehicle arrives at the destination, the destination is automatically set as the departure point and the departure point of the forward route is automatically set as the destination, and the return route is automatically set using the stored return route data.
However, with the return route setting shown in Patent Document 1, it is possible to respond to a user's request to pass on the way back as far as possible. However, when setting a waypoint to stop in the middle of setting the forward route, the forward route is set as a route passing through the waypoint. For this reason, when it passes through the waypoint when returning, it usually becomes a return route with a long traveling distance.

  The present invention has been made in view of the above circumstances, and its purpose is to automatically set a return route with a short mileage while satisfying as much as possible the requirement to pass the same road as when returning. An object of the present invention is to provide a return route setting method and a car navigation device in a car navigation device.

  In order to achieve the above object, in the present invention, a forward route from the departure place to the destination is stored, and when arriving at the destination, a return route candidate from the arrival place to the departure place under a predetermined condition When the return route candidate branches from the forward route and does not merge with the forward route at the branch destination, a new return route candidate from the branch point to the departure point is added to the predetermined condition. The return route from the arrival point to the departure point is set by executing the determination on the condition that it joins the forward route, so that the request to pass the same route as the forward route is satisfied as much as possible. However, it is possible to set a return route with a short travel distance.

    Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram functionally showing the overall configuration of the car navigation apparatus. As shown in the figure, the car navigation device 1 includes a calculation unit 2, a current position measurement unit 3 as a current position acquisition unit, a map data storage unit 4 as a map data acquisition unit, a display unit 5 as a display unit, and a forward path. , A route storage unit 6 as a storage unit, a route storage unit 7 as a guide route storage unit, a voice storage unit 8, a speaker 9, an input unit 10 as an input unit, and the like.

  The current position measuring unit 3 includes a gyroscope 11 that detects the pitch angle of the vehicle, a G sensor 12 that detects the rolling angle of the vehicle, a distance sensor 13 that detects a travel distance, and a GPS (Global Positioning System) receiver 14. Etc. are connected. Since these sensors 11 to 14 have detection errors of different properties, combining these sensors 11 to 14 enables highly accurate position detection while correcting the detection errors. Then, the current position measurement unit 3 determines the current position of the vehicle based on the detection results of these sensors 11 to 14 and the like.

  The map data storage unit 4 is composed of an information recording medium such as a DVD-ROM and a reading device that reads map data from the information recording medium. The map data, map matching data, and the route are voiced by the reading device. The data for guidance is read and given to the calculation unit 2. The map data is data for displaying a map on the display unit 5 and includes link information, node information, and the like. This is to divide the road on the map into multiple parts by nodes that show inflection points such as intersections, branch points, merge points, curves over a predetermined angle, etc., define each link as a link, and connect these links Based on the idea of constructing a map.

  The display unit 5 includes a display screen such as a liquid crystal display, and can display map data, characters, symbols, or the like on the display screen. The input unit 10 is used for inputting data and inputting various setting items. For example, the input unit 10 includes various switches such as a touch panel or a mechanical switch provided integrally with the display unit 5. Yes.

  The calculation unit 2 includes a display control unit 15, a route calculation unit 16, a route guidance control unit 17, a voice control unit 18, and the like. The display control unit 15 acquires current position information from the current position measurement unit 3, and displays a road map around the current position on the display screen of the display unit 5 based on the map data acquired from the map data storage unit 4. The pointer indicating the current position and the traveling direction of the vehicle is displayed on the road map on the display screen.

  The route calculation unit 16 functions as a guide route search unit, and searches for a route from the departure point (usually the current location) to the destination. When the waypoint is designated, the route calculation unit 16 searches for a route that passes through the route point and reaches the destination. The waypoints and destinations are input from the input unit 10 that functions as waypoint setting means and destination setting means. In this case, the waypoints and destinations can be entered using a method of specifying any point on the map displayed on the display screen of the display unit 5, a method of specifying a place name, etc., a telephone number, and a facility name. You can choose from the methods to do.

  When the waypoint and the destination are set from the input unit 10, the route calculation unit 16 passes the route from the current position to the destination or the route from the current position based on the map data in the map data storage unit 4. Search for a route to the destination. In this case, the route calculation unit 16 searches for a plurality of routes on the condition of distance priority, toll road priority, and the like. When the user performs an input operation for designating (setting) a desired guide route from among the plurality of routes, the route is set as the guide route and stored in the route storage unit 7. The Dijkstra method or the like is used as a method for searching for a guidance route.

  The route guidance control unit 17 functioning as a route guidance unit and a route control unit reads out the guidance route stored in the route storage unit 7 and displays the guidance route on the road map of the display unit 5 via the display control unit 15. To display. Then, the route guidance control unit 17 obtains the current position from the current position measurement unit 3, and when the vehicle approaches the intersection to be changed, the name of the intersection is displayed on the display screen of the display unit 5 via the display control unit 15. The distance to the intersection is displayed, or the intersection is enlarged and the traveling direction is displayed with an arrow. In addition, the route guidance control unit 17 issues an instruction to the voice control unit 18 in order to provide guidance on the route at the intersection along with the display of the name of the intersection and the distance to the intersection.

  The voice control unit 18 reads information stored as digital data in the voice storage unit 8 based on an instruction from the route guidance control unit 17, converts the information into an analog signal, and drives the speaker 9. As a result, a route instruction such as “Approximately *** m ahead intersection is in the * direction” is given by voice from the speaker 9 to guide the route.

  The route guidance control unit 17 detects whether or not the current position of the vehicle is on the guidance route when the guidance route is set, and resets the route to the route calculation unit 16 when leaving the guidance route. Issue a command. Upon receiving the route resetting instruction, the route calculation unit 16 newly sets a guide route from the current position to the destination or a guide route from the current position to the destination via the waypoint, and the route calculation unit 16 adds a new route to the destination. The guide route is changed to the original guide route and stored. Therefore, the route calculation unit 16 also functions as a reroute setting unit.

  In the car navigation device of the present embodiment, when a guidance route is set, a return route that returns to the departure point is automatically set upon arrival at the destination. Hereinafter, the automatic setting of the return path will be described with reference to the flowchart of FIG.

First, if there is a destination at the departure point and a stopover point where the user wants to drop in, a route point is input from the input unit 8 (step S1 in FIG. 2).
Then, the route calculation unit 16 searches for a route from the departure point to the destination, or from the departure point to the destination via the waypoint (route search means). Since the route search in this case is performed under a plurality of conditions such as distance priority and toll road priority, a plurality of routes are searched. When the user selects a desired route from the plurality of routes, this is set as a guide route (outward route) and stored in the route storage unit 7 (step S2). Here, as shown in FIG. 3, it is assumed that a route point T and a destination point E are input, and a guide route from the departure point S to the destination point E via the route point T is set as indicated by a thick line indicated by G. .

  When the vehicle starts to travel, the route guidance control unit 17 controls the display control unit 15 and the voice control unit 18 in order to guide the vehicle along the guidance route (step S3). The actual travel route is stored in the travel route storage unit 6 until the vehicle arrives at the destination (step S4). The travel route is acquired by the route guidance control unit 17 by superimposing the current position information obtained from the current position measurement unit 3 on the map data obtained from the map data storage unit 4 (travel route acquisition means). ).

  When the route guidance control unit 17 determines that it has arrived at the destination E (step S5: destination arrival determination means), the route calculation unit 16 sets the travel route stored in the travel route storage unit 6 as the actual forward route. (Step S6). In this case, the arrival determination at the destination E may be performed when the position of the vehicle coincides with the destination E, or may be performed when the vehicle is within a predetermined distance from the destination E.

  Next, the route calculation unit 16 sets the arrival point as the departure point of the return route and the departure point of the outward route as the destination of the return route, and automatically sets the return route. The travel route stored in the storage unit 6) is determined as a provisional return route, and this provisional return route is partitioned into predetermined unit points, for example, intersections, and divided into a plurality of unit routes (step S8). For example, if the forward route is the same as the guide route indicated by G in FIG. 3, the provisional return route Rp is determined as shown by the broken line in FIG. Are divided into unit paths G1 to G8.

  Next, the route calculation unit 16 searches for a return route candidate so as to have a predetermined condition, for example, distance priority, that is, the shortest distance (step S9: return route candidate calculation means), and the searched return route candidate is set to a predetermined breakpoint, For example, each intersection is divided into a plurality of unit routes (step S10: partitioning means). When applied to the example of FIG. 4, the return route candidate R1 is determined as indicated by a solid line, and this return route candidate R1 is divided into intersections R1-1 to R1-5 for each intersection. In the following description, it is assumed that the provisional return route Rp and the return route candidate R1 are determined as shown in FIG.

  Thereafter, the route calculation unit 16 compares the unit routes R1-1 to R1-5 of the return route candidate R1 with the unit routes G1 to G8 of the provisional return route Rp in order from the departure point (the arrival point on the outbound route) E side. Go (step S11). This comparison is for determining whether or not the unit routes R1-1 to R1-5 of the return route candidate R1 match the unit routes G1 to G8 of the provisional return route Rp, and whether or not to join. . Here, “match” means that the same road is passed, and “merge” means that the end points of the unit sections match (except for match at the destination). When entering this comparison operation, the route calculation unit 16 first compares the first unit section R1-1 of the return path candidate R1 with the first unit section G1 of the provisional return path Rp.

  Since the first unit section R1-1 of the return path candidate R1 matches the first unit section G1 of the provisional return path Rp, the path calculation unit 16 determines the next match / mismatch step S12 (match determination means) ) And “YES”, the unit section R1-1 is determined as the return path (step S13). Next, it is determined whether or not a return route has been established to the destination S (step S14). Here, since the route to the destination S has not yet been determined, the route calculation unit 16 determines “NO” and proceeds to step S11.

  In this step S11, the route calculation unit 16 obtains the second unit partition R1-2 of the return route candidate R1 and the second unit partition G2 of the provisional return route Rp (the next unit route of the matched unit route). Compare. Since the unit section R1-2 and the unit section G2 coincide with each other, the route calculation unit 16 determines “YES” in step S12, confirms the return route in step S13, and again performs step S11 through step S14. Migrate to

  In step S11, the route calculation unit 16 compares the third unit partition R1-3 of the return route candidate R1 with the third unit partition G3 of the provisional return route Rp. Since the unit section R1-3 branches from the unit section G3 at the intersection indicated by C1 in FIG. 4, the route calculation unit 16 determines “NO” in step S12 and determines whether or not it is the next merge. In step S15 (merging determination means), “NO” is determined, and the process proceeds to step S16.

  In step S16, the route calculation unit 16 determines whether or not comparison has been made up to the final section (R1-5) of the return route candidate. Here, since the final section is not determined, the route calculation unit 16 determines “NO” in step S16, returns to step S11, and selects the next unit partition R1-4 of the return route candidate R1 after the branch intersection C1. Are compared with the unit sections G3 to G8 of the provisional return path Rp. Then, the route calculation unit 16 determines whether or not the unit section R1-4 matches any one of the unit sections G3 to G8.

  In the example of FIG. 4, the unit section R1-4 does not match or merge with any of the unit sections G3 to G8 (both “NO” in step S12 and step S15), so the route calculation unit 16 returns to step S11. The final unit section R1-5 of the return path candidate R1 is compared with the unit sections G3 to G8 of the provisional return path Rp after the branch intersection C1, and the unit section R1-5 matches any of the unit sections G3 to G8. It is determined whether or not to join. Since the unit section R1-5 does not match or merge with any of the unit sections G3 to G8, and the unit section R1-5 is the final section, the route calculation unit 16 determines “NO” in step S12, and in step S15. “NO”, “YES” in the step S16, the process shifts to a step S17.

  In step S17, the route calculation unit 16 uses the end of the route determined as the return route from the departure point E, here the end of the unit route R1-2, that is, the intersection C1 that is a branch point, and the destination S as the end point. A new return route candidate to be searched is searched (return route candidate calculation means). In this case, a new return path candidate is searched for by adding the predetermined condition, that is, the condition that the return path candidate joins the temporary return path Rp at the shortest distance without returning. As a result of this search, if a new return route candidate R2 indicated by a one-dot chain line in FIG. 5 is searched, the route calculation unit 16 proceeds to step S10 and divides this new return route candidate R2 for each intersection. It is divided into a plurality of unit paths R2-1 to R2-4.

  Then, the route calculation unit 16 compares the unit routes R2-1 to R2-4 of the new return route candidate R2 with the unit routes G3 to G8 after the intersection C1 of the temporary return route Rp in order from the destination E side. Are matched (step S11, step S12). Since this comparison shows that the unit route R2-2 joins with the unit route G6 of the provisional return route Rp, the route calculation unit 16 determines “YES” in step S15, and starts from the junction C1 (see FIG. The unit routes R2-1 and R2-2 of the return route candidate R2 up to 5) are determined as return routes (step S17).

  Thereafter, the route calculation unit 16 returns to step S11 and sequentially starts the unit route (R2-3) and subsequent units after the unit route determined as the return route, and starts with the unit section (starting from the confluence of the provisional return route Rp). G7) Comparison with the subsequent steps (step S11). As a result of the comparison, the unit routes R2-3 and R2-4 of the return route candidate R2 all match the unit routes G7 and G8 of the provisional return route Rp, so that the route calculation unit 16 determines “YES” in step S12, In S13, unit paths R2-3 and R2-4 are determined as return paths. When the unit route R2-4 is determined as the return route, the return route to the destination S is determined, so that the route calculation unit 16 becomes “YES” during the subsequent execution of step S14. Routes R1-1, R1-2, R2-1, R2-2, R2-3, and R2-4 are set as return routes from the departure point E to the destination S, and become the end.

  The return path is set as described above. Thereafter, when the vehicle is driven, guidance for guiding the vehicle along the return route as described above is performed, and the vehicle arrives at the destination S. By traveling the vehicle according to such a return route, it is possible to change through the same road as when the vehicle came in as short a distance and as long as possible.

The present invention is not limited to the embodiments described above and shown in the drawings, and can be expanded or changed as follows.
The return route may be determined not to the actually traveled route but to the initially set guide route.
It is not limited to the case where there is a transit point T in the middle of the outbound route.
The traveling path storage unit 6 and the route storage unit 7 may be configured by different storage areas as one storage unit.

1 is a block diagram of a car navigation apparatus showing an embodiment of the present invention. Flow chart for route setting Schematic map showing an example of the outbound route A map for explaining the procedure to set a return route part 1 A map for explaining the procedure to set a return route part 1

Explanation of symbols

  2 is a calculation unit, 3 is a current position measurement unit, 4 is a map data storage unit, 5 is a display unit, 6 is a travel route storage unit (storage means), 7 is a route storage unit, 15 is a display control unit, and 16 is a route. A calculation unit (return route candidate calculation unit, coincidence determination unit) and 17 are a route guidance control unit (destination arrival determination unit).

Claims (2)

In a car navigation device that can set a guide route from a departure point to a destination or from a departure point to a destination via a transit point,
Remember the outbound route from your starting point to your destination,
When arriving at the destination, a return route candidate from the arrival point to the departure point is obtained under a predetermined condition, and when the return route candidate branches from the forward route and does not join the forward route at the branch destination, A new return route candidate from the branch point to the departure point is obtained on the condition that the return route candidate joins the forward route in addition to the predetermined condition. A return route setting method in a car navigation device, characterized in that the return route is set. In a car navigation device that can set a guide route from a departure point to a destination or from a departure point to a destination via a transit point,
Storage means for storing the outbound route from the departure place to the destination;
Destination arrival judging means for judging that the vehicle has arrived at the destination;
When it is determined that the destination has arrived at the destination by the destination arrival determination means, return path candidate calculation means for obtaining a return path candidate from the arrival place to the departure place under a predetermined condition;
A match determination unit that divides the return route candidate obtained by the return route candidate calculation unit into a plurality of unit routes, and determines whether or not the return route side unit route sequentially matches the forward route;
A return path setting means for setting, as a return path, a unit path determined by the match determination means to match the forward path among the unit paths of the return path candidate;
The return route candidate calculation means, when it is determined by the match determination means that the unit route of the return route candidate does not match the forward route and branches, a new return route from the branch point to the departure point The candidate is calculated on the condition that it joins the forward route in addition to the predetermined condition, and is configured to set a return route from the arrival location to the departure location. Car navigation device.

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