JP2002148066A - Route searching device and medium thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a route searching device with which the user can search the route along which the user can reach its destination from a starting point in a short time. SOLUTION: An arithmetic section 12 prepares an intersection network model containing information on intersections and road data from map data stored in a map data storing section 14, and stores the model in a memory 16. The information on intersections contains the presence/absence of traffic signals, road widths, intersecting angles, etc., at intersections. The arithmetic section 12 selects routes having smaller numbers of intersections to be passed and smaller numbers of traffic signals from among possible routes leading to the destination from the starting point, and outputs the selected routes to a display device 18 or printer 20. In addition, the arithmetic section 12 preferentially selects such a route that has intersections suitable for right- and left-hand turns by evaluating whether or not its own vehicle can make smooth right- and left- hand turns at the intersections based on the road widths, and intersecting angles at the intersections by assuming the running state of an autotruck or large-sized trailer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route search device and a medium, and more particularly to a technique for searching for a route from a departure point to a destination in consideration of an intersection.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique in which a navigation device searches for a route from a departure point input to a destination by a Dijkstra method or the like and displays the obtained route to guide a vehicle. In such a navigation technology, how to efficiently search for an optimal route is an important issue.

For example, Japanese Patent Application Laid-Open No. H11-304518 discloses that a route obtained by a search is evaluated based on the number of lanes, a road type, a distance, an average speed, a traffic regulation, a signal interval, etc. A technique for finally selecting a route is described.

[0004]

According to this prior art, it is possible to preferentially select a road having a short distance, a large average speed, and no traffic restrictions. In many cases, these conditions alone are not sufficient. For example, even if it is the shortest distance from the departure point to the destination, if there are many intersections, it is considered that the traveling speed will decrease by stopping temporarily, etc. It will take some time to reach the destination. Furthermore, considering not only the case of traveling by passenger car but also the case of transporting goods by, for example, a large truck or a trailer, there may be some intersections where it is not possible to turn right or left depending on the intersection or it takes time to turn right or left (for example, Turning back makes it possible to turn left.)

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to search for a route to a destination with higher accuracy than ever before, and is optimal for not only ordinary vehicles but also large vehicles. It is an object of the present invention to provide a device that can reach a destination by a simple route.

[0006]

In order to achieve the above object, the present invention provides an apparatus for searching for a route from a departure place to a destination, comprising: storage means for storing map data; Computing means for searching for a route from the departure point to the destination based on the number of passing intersections. Rather than simply searching for the shortest route, by considering the number of passing intersections, it is possible to more reliably obtain a route that can reach the destination in a short time.

Here, it is preferable that the calculating means further calculates a route from the departure point to the destination on the basis of the presence or absence of a traffic light at a passing intersection. At an intersection where a traffic light exists, there is a possibility that the vehicle stops at a red light or the like as compared with a case where there is no traffic light, so it is difficult to pass the traffic quickly. Therefore, by considering the presence or absence of a traffic light, it is possible to more reliably obtain a route that can reach the destination in a short time.

It is preferable that the calculating means further calculates a route from the departure place to the destination on the basis of a width, an intersection angle and a vehicle size at the passing intersection. In the case of a large vehicle, it is difficult to make a right or left turn depending on the size of the intersection, and it may take time to pass through the intersection. Therefore, a route suitable for the size of the vehicle can be obtained by considering the size of the intersection, specifically, the width of the exit road or the approach road, the intersection angle, and the size of the vehicle.

In one embodiment of the present invention, the calculating means extracts a possible route from the departure place to the destination, and evaluates the extracted route based on the number of passing intersections. Evaluation means, wherein the extraction means generates means of an intersection network model along the x direction and the y direction orthogonal to each other from the map data, and in the intersection network model, a starting point at an intersection near the departure point; The direction of the component whose actual distance is large among the components of the vector having the intersection near the destination as the end point is selected, and the selection is repeated with the intersection existing when proceeding from the start point in the selected direction as the new start point. Means for extracting the possible routes. According to such a search algorithm, it is possible to easily select a route that can go straight as far as possible.

The present invention also provides a computer-readable recording medium for recording a program for searching for a route from a starting point to a destination. The program causes a computer to search at least for a possible route from the departure point to the destination, to count intersections through which the possible route passes, and to select a route with a small count value. .

Here, the intersection is an intersection having a traffic light, and it is preferable that a route with a small number of traffic lights is selected.

Preferably, the program causes a computer to evaluate the possible route using a width, an intersection angle, and a vehicle size at an intersection through which the possible route passes.

[0013] The program may execute the above-described functions in cooperation with an operating system.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment. The overall configuration is almost the same as the conventional navigation system, and the input device 10, the position detection device 1
1, a calculation unit 12, a map data storage unit 14, a memory (main storage unit) 16, a display device 18, and a printing device 20. The input device 10 includes an operation button, a touch switch, and the like, and a user inputs a destination. Of course, the input device 10 can also be constituted by a microphone and a voice recognition device.

The position detecting device 11 can be constituted by GPS, DGPS, or the like, and the detected current position of the vehicle is output to the arithmetic section 12.

The map data storage unit 14 stores data on a CD-ROM or D
It is composed of VD or the like and stores map data. The map data may include, in addition to the display map data, map data in which road data on the map data is connected by links and nodes. In the present embodiment, the actual route search uses not the map data or the map data itself including links and nodes, but an intersection network model created based on these. The intersection network will be described later.

The arithmetic unit 12 is specifically composed of a microcomputer, and the destination input from the input device 10, the current position of the vehicle detected by the position detecting device 11, and the map stored in the map data storage unit 14. A route from the departure point to the destination is searched based on the data, and the obtained result is output to the display device 18 or the printing device 20. When searching for a route from the departure point to the destination, the calculation unit 12 creates an intersection network model along the x-direction and the y-direction orthogonal to each other from the map data stored in the map data storage unit 14, and stores it in the memory 16. Search for possible routes to the destination based on the stored intersection network model. The possible routes obtained are likewise stored in the memory 16. The memory 16 can be composed of, for example, a RAM. Then, of the obtained possible routes, a route that satisfies a predetermined condition, specifically, a route having a small number of passing intersections is selected and output to the display device 18 or the printing device 20.

FIG. 2 shows the operation unit 12 according to this embodiment.
Is shown. First, the calculation unit 12 creates an intersection network model based on the map data stored in the map data storage unit 14 (S1).
01).

FIG. 3 shows a detailed flowchart of this intersection network model creation processing. FIGS. 4 and 5 show examples of map data (display map data) and map data shown in FIG. The created intersection network model is shown. As shown in FIG.
The calculation unit 12 first reads map data from the map data storage unit 14 (S201). Next, an intersection network model is created from the map data (S202).

Now, map data 10 as shown in FIG.
Assume that 0 has been read. Generally, road data in map data is formed by various roads intersecting at various angles. The computing unit 12 first extracts a connection relationship in which the intersection is replaced by a node and a road connecting the intersections is replaced by a link from these map data. And along the y direction. At this time, all the two roads intersecting at a certain angle may be arranged in the x direction and the y direction, respectively. For example, as shown at point P in FIG. At an intersection that intersects at the following acute angle and cannot be arranged so as to be orthogonal to each other as it is, the original node corresponding to the intersection is divided into two nodes, and the two nodes are connected by a pseudo link. It is arranged in either the direction or the y direction. FIG. 5 shows the intersection network model 102 created in this way. In the figure, C1, C2, ... represent nodes corresponding to intersections, and R1, R2, ... represent links connecting the intersections. Note that all the links are orthogonally arranged along either the x or y direction. The nodes corresponding to the point P in FIG.
7-b, and the pseudo link connecting these two nodes is denoted by X1, and the normal link R1,
R2,... Each node and link is provided with intersection information and road information corresponding to the node or link. For example, for node C1, attribute: intersection data, intersection: yes, etc., and for link R1, attribute: road data Line segment: C1-C8 distance: 450m Restriction: heavy vehicle entry prohibited, 7: 00-9: 00 traffic Prohibition, one-way C1 → C8, speed level: 1, etc. In addition, as the data to be assigned to the node, it is preferable to further add the presence or absence of a traffic light when there is an intersection. For example, Attribute: Intersection data Intersection: Yes Traffic light: Yes When there is an intersection, it is preferable to add the width of the road and the intersection angle at the intersection. For example, if an intersection is located at 2 as shown in FIG.
Attribute: Intersection data Intersection: Available Width: A, B Intersection angle: C (when A is an exit road, when turning left), D
(When turning right when A is the exit road). Incidentally, it goes without saying that 0 m is given as the distance data for the pseudo link X1 that does not actually exist. The presence or absence of a traffic light can be represented by setting the value of a flag to 0 or 1.

When the intersection network model is created from the map data in this way, the arithmetic section 12 stores the created intersection network model in the memory 16 as shown in the flowchart of FIG. 3 (S203). Therefore, the memory 16 includes intersection information (presence or absence of an intersection and presence or absence of a traffic light), intersection network information (a positional relationship or a connection relationship between the intersections), distance information between the intersections, traffic restriction condition information (such as prohibition of entering a large vehicle), The traveling speed level and the intersection size information (the width and the intersection angle at the intersection) are stored.

Returning again to FIG. 2, the operation unit 12
6, a possible route to the destination is searched based on the data stored in the memory 6 (S102), the obtained route is evaluated using the data stored in the memory 16, and an optimal route is selected. (S103).

FIG. 7 is a processing flowchart for searching for a possible route from the departure point to the destination using the data stored in the memory 16. First, the calculation unit 12 obtains a predetermined number, for example, two, of intersections (nodes) closer to the departure point (the detected current position can be set as the departure point) in the intersection network model, in the order of decreasing distance. (S301).

FIG. 8 shows the relationship between the departure point and the intersection network model. When C1 and C2 exist as intersections (nodes) near the departure point O, these C1 and C2 are selected as departure intersections. of course,
If there is only one intersection near the departure point, only one of them is set as the departure intersection. Of course, it is also possible to select only one departure intersection closest to the departure point. Next, at the destination, similarly, a predetermined number, for example, two points, of the intersections close to the destination are determined in ascending order, and this is set as the destination intersection (S302). After selecting the departure intersection and the destination intersection, one departure intersection and one destination intersection that have not yet been processed are selected (S303, S30).
4). For example, there are C1 and C2 as departure intersections,
When C100 and C101 exist as destination intersections,
A pair (C1, C100) is selected. Then, the departure intersection and the destination intersection are connected by a straight line on the intersection network model, and the x component and the y component of this line segment are extracted (S30).
5). That is, a vector is formed with the departure intersection as the start point and the destination intersection as the end point, and the x and y components of this vector are extracted.

FIG. 9 shows a vector 104 created in this manner. The x component of the vector 104 is a component 106 and the y component is a component 108. After extracting the x and y components of the vector connecting the departure intersection and the destination intersection, the absolute value of the extracted x and y components on the intersection network coordinates is calculated (S306). Here, the absolute value on the intersection network coordinates means the actual distance given to the links arranged in the x direction and the y direction,
For example, when the y component 108 includes links R1, R2, and R3, the actual distance of the link R1 is 100 m, the actual distance of the link R2 is 150 m, and the actual distance of the link R3 is 120 m, the absolute value of the y component 108 is 100 + 150 + 120. =
370. If the length of the x component or the y component does not match the link, the absolute value can be calculated by, for example, proportional distribution. For example, on the intersection network, when the x component 106 corresponds to half the length of the link R5 and the actual distance of the link R5 is 200 m, the absolute value of the x component 106 is 200 × 1/2 =
It can be 100.

After calculating the absolute values of the x component 106 and the y component 108 of the vector 104, these absolute values are compared in magnitude (S307). Then, the one having the larger absolute value is selected, and this direction is set as the direction to proceed from the departure intersection (S
308). For example, in the example of FIG. 9, when the x component 106 is 100 and the y component 108 is 370, the direction to proceed is selected as the y direction because the absolute value of the y component is larger than the x component. Is done. The significance of selecting the one with the larger absolute value is that the vehicle travels straight to gain as much distance as possible and to approach the destination. In selecting a direction to travel, it is preferable to consider traffic constraint conditions. For example, when entry in the y direction is prohibited at the departure intersection, even if it is determined that the vehicle should proceed in the y direction as a result of the magnitude comparison between the x component and the y component, x
Select a direction. Of course, it is also preferable to compare the absolute values after confirming that the vehicle can enter both the x direction and the y direction.

After selecting the direction to proceed from the departure intersection, the first intersection (node) existing in the selected direction is set as the next new departure intersection (S309). In FIG. 9, when the y direction is selected and an intersection On exists in the y direction, this On is selected as the next departure intersection. Then, after confirming that the newly selected departure intersection is not the intersection that has already passed (NO in S310) and is also not the destination intersection (NO in S312), the processing from S305 is repeated, and the new intersection is repeated. Create a vector with the departure intersection as the start point and the destination intersection as the end point, compare the absolute values of the x and y components, select the larger direction, and set the first intersection existing in the larger direction as the new departure. Intersection.

If the newly set departure intersection is an intersection that has already passed, it means that the vehicle has returned to the intersection that has already passed and that it cannot reach the destination by circulating. The existing route portion is made unselectable, and another intersection, for example, the other intersection (intersection in the x-direction when it becomes a passed intersection when it proceeds in the y-direction) is set as a new departure intersection ( S31
0, S311).

The above processing is repeatedly executed until the target intersection is reached, and the sequentially selected nodes and links are stored in the memory 1.
6 (S312).

In the processing of S307, the x component and y
If the absolute values of the components are equal, an intersection in which the vehicle travels in both the x direction and the y direction is set as a new departure intersection (S315). Therefore, in this case, there are two departure intersections, and a route search is executed for each of them.

The above processing is performed for all combinations of the departure intersection and the destination intersection, and a possible route from the departure intersection to the destination intersection is searched (S313, S31).
4).

As described above, by sequentially selecting a component having a larger absolute value from the x component and the y component as the traveling direction, a route that can be reached as straight as possible from the departure intersection to the destination intersection is selected. be able to. Also, an intersection network model having only the x and y directions is created from the map data, and a route is searched based on this model. The intersection network is an abstraction of the actual road positional relationship. Therefore, it is also possible to search for a route that detours from the departure point to the destination (particularly, when a plurality of intersections close to the departure point are selected as departure intersections, a detour route is searched for). ). The above is the search process of the possible route performed by the arithmetic unit 12.

FIG. 10 is a flowchart showing an evaluation process for obtaining a more optimal route for a possible route to the destination. First, the calculation unit 12 stores all the routes obtained by the above-described processing in the memory 16 as a set of intersection data (nodes) and road data (links) (S401). Since the sequentially selected nodes and links are already stored in the memory 16, specifically, a number for identifying each of these sets,
For example, a route K1, a route K2,. Each node and link is provided with the presence or absence of a traffic light, distance data, and intersection size data. Then, the evaluation point S given for each route is reset to the initial value 0 (S40).
2).

Next, for all the obtained routes, the total travel distance is calculated from the road data (link) on the intersection network (S403). For example, the obtained route K1
Is road data (link) R10 (distance 100m), R1
1 (distance 200 m) and R12 (distance 300 m), the total travel distance of the route K1 is 100+
200 + 300 = 600 m. The above distance calculation is performed for all routes. Then, an evaluation point predetermined according to the total traveling distance is given to each route (S40).
4). The evaluation points can be determined such that, for example, the smaller the total traveling distance is, the larger the evaluation points are. Thus, the evaluation points can be set higher for a route having a smaller total traveling distance. As described above, the evaluation points based on the traveling distances are given to all the obtained routes.

Next, the arithmetic section 12 counts the number of intersections passing through all the obtained routes (S405). For example, a certain route K2 has intersections (nodes) C1, C2, and C3.
, The count value is 3. Then, based on the relationship between the predetermined count value (the number of passing intersections) and the evaluation points, evaluation points corresponding to the number of passing intersections are given to all the routes (S406). The evaluation points can be set to be larger, for example, as the number of passing intersections is smaller, so that a route having a smaller number of passing intersections can have a higher evaluation point. As described above, evaluation points based on the number of passing intersections are given to all the obtained routes. It should be noted that a passing intersection is counted if it passes through the intersection regardless of whether it turns right or left at the intersection.

The calculation unit 12 performs the same processing according to the number of intersections to turn right and left and the speed level, and gives an evaluation point to each route. At this time, it is preferable that the evaluation point is set higher as the number of intersections turning right and left is smaller, and the evaluation point is set higher as the speed level increases.

Further, the arithmetic section 12 counts the number of intersections where traffic signals are present on all the routes, and gives a predetermined evaluation point based on the counted value (S412). At this time, it is preferable that the smaller the number of traffic signals, the higher the evaluation point. Needless to say, the counting of traffic signals is performed based on the attribute data assigned to the passing intersection (node). For example, the passing intersection on the route K3 is C5,
If the traffic lights are C6 and C7 and only the traffic light exists at C5, the count value becomes 1.

Further, the calculation unit 12 gives an evaluation point based on the intersection size and the vehicle size to each route (S41).
3). This evaluation is based on the width, intersection angle and vehicle size of the road at the right / left turn intersection. Mode 1: Passing in only one side lane without turning over Mode 2: Passing by protruding into the oncoming lane without turning back Mode 3: Returning Is determined by determining which of the three required modes is applicable, and by giving an evaluation score for each mode. Which of the modes corresponds to, for example, the relationship between the width of the road, the intersection angle, the vehicle size and the mode is determined experimentally or by simulation, etc.
6, the size of the target intersection, the size of the target vehicle, and the table may be referred to to determine the size. It is preferable to set the evaluation points higher in the order of mode 1>2> 3. The user can input the vehicle size from the input device 10 to the calculation unit 12 in advance. As for the vehicle size, 3 types of small car / normal car / large car
Types may be used.

As described above, the calculation unit 12 evaluates each route based on the total traveling distance, the number of passing intersections, the number of right and left intersections, the speed level, the presence or absence of a traffic light, and the size of the intersection. The best route (the highest evaluation score) is selected as the optimum route (S414). That is, the evaluation points of the traveling distance, the number of passing intersections, the number of right and left intersections, the speed level, the presence or absence of a traffic light, and the size of the intersection are S1,
When S2, S3, S4, S5, and S6 are set, the evaluation point S =
Select the path with the largest ΣSi. Of course, the evaluation points may be calculated as S = ΣαiSi with each evaluation point Si having a weight αi. Here, the weight can be changed according to the vehicle size. For example, in the case of a large vehicle as compared with the case of an ordinary vehicle, the weight of the intersection size is increased, and a route is selected with more emphasis on the intersection size. As a result, it is possible to select an optimum route according to the vehicle size, instead of simply selecting a route with few left and right turns. It will also be understood that the optimal route may vary for heavy and heavy trucks.

It is also preferable that the weight can be appropriately adjusted by the user. For example, for a user who wants to reach a destination in as short a time as possible, it is preferable to increase the weight of the number of passing intersections and the weight of the presence or absence of a traffic light. As a result, rather than the traveling distance, the number of passing intersections is as small as possible, and a route without a traffic light is preferentially selected.

In this embodiment, each route is evaluated based on a plurality of evaluation items. Of course, it is also possible to evaluate based on only the number of passing intersections, only the presence or absence of a traffic light, or only the size of an intersection. It is possible.

In this embodiment, the intersection network model is created from the map data. However, it is not necessary to replace all the map data with the intersection network model, and only the range considered necessary for the route search is used. It can also be. For example, as shown in FIG. 11, a circle having a predetermined radius centered on the departure point and the destination point may be assumed, and only map data existing within these two circles may be subjected to network modeling. . An elliptical range focusing on the departure place and the destination may be targeted, and a predetermined rectangular range including the departure place and the destination may be targeted.

In the present embodiment, the arithmetic unit 12 performs the route search process shown in FIG. 7 and the evaluation process shown in FIG. 10, but executes the route search process by another method.
The evaluation process shown in FIG. 10 can be executed on the obtained route. This also provides a route with a small number of passing intersections, a small number of traffic lights, or an intersection size.

The processing of FIG. 3 (intersection network creation processing), the processing of FIG. 7 (possible route search processing), and the processing of FIG.
Processing can be performed by sequentially executing the installed programs by the microcomputer as the second. Such a program is stored on a hard disk or CD-RO
M, DVD, etc. Of course, if the map data storage unit 14 has an intersection network model in advance, the arithmetic unit 12 simply reads out the data and stores it in the memory 16, and the processing shown in FIG. Become.

[0046]

As described above, according to the present invention, a route which can reach a destination in a shorter time can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an overall processing flowchart of the embodiment.

FIG. 3 is a detailed flowchart of an intersection network model creation process in FIG. 2;

FIG. 4 is an explanatory diagram of map data.

FIG. 5 is an explanatory diagram of an intersection network model of the map data shown in FIG. 4;

FIG. 6 is an explanatory diagram of a width and an intersection angle (intersection size) at an intersection.

FIG. 7 is a flowchart for searching for a possible route to a destination in the embodiment.

FIG. 8 is an explanatory diagram of selection of a departure intersection.

FIG. 9 is an explanatory diagram showing a vector connecting a departure intersection and a destination intersection, and its x point and y component.

FIG. 10 is a flowchart of a route evaluation process according to the embodiment.

FIG. 11 is an explanatory diagram of a range to be modeled in another embodiment.

[Explanation of symbols]

10 input device, 11 position detection device, 12 operation unit,
14 map data storage unit, 16 memory, 18 display device, 20 printing device.

Claims (7)

[Claims] 1. An apparatus for searching for a route from a departure place to a destination, comprising: storage means for storing map data; and, based on the map data, from the departure place to the destination based on the number of passing intersections. A route search device comprising: a calculation unit that searches for a route. 2. The route search device according to claim 1, wherein said calculation means further calculates a route from said departure point to said destination based on the presence or absence of a traffic light at a passing intersection. 3. The apparatus according to claim 1, wherein the calculating means further calculates a route from the departure point to the destination based on a width, an intersection angle, and a vehicle size at the passing intersection. Route search device. 4. The apparatus according to claim 1, wherein the calculating means extracts a possible route from the departure place to the destination, and evaluates the extracted route on the basis of the number of passing intersections. Means for generating an intersection network model along the x-direction and the y-direction orthogonal to each other from the map data; and, in the intersection network model, an intersection near the departure point. The direction of the component whose actual distance is large among the components of the vector having the start point and the intersection near the destination as the end point is selected, and the intersection existing when proceeding from the start point in the selected direction is selected as the new start point. Means for extracting the possible route by repeating the following. 5. A computer-readable recording medium for recording a program for searching for a route from a departure place to a destination, wherein the program is provided to a computer for a possible route from the departure place to the destination. A medium, characterized in that a search is made for the number of intersections through which the possible route passes, and a route with a small count value is selected. 6. The medium according to claim 5, wherein the intersection is an intersection having a traffic light. 7. The medium according to claim 5, further comprising:
The medium, wherein the program causes the possible route to be evaluated using a width, an intersection angle, and a vehicle size at an intersection through which the possible route passes.