JP2836525B2 - Route guidance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route for guiding a driver by instructing a traveling route for each important point such as an intersection based on a route set to a destination or a route calculated to a destination. The present invention relates to a guidance device.

[0002]

2. Description of the Related Art Conventionally, there has been a navigation apparatus having a function of automatically calculating and displaying a shortest route by simply setting a destination and displaying the shortest route by a voice or an enlarged view of an intersection when approaching an intersection on the route. Known (Japanese Unexamined Patent Publication No.
-80697). This navigation device is equipped with a direction sensor, a distance sensor, a GPS receiver, a road map memory, a computer, and the like in a vehicle. The direction data input from the direction sensor, the traveling distance data input from the distance sensor, and the GPS receiver In order to determine the shortest route from the current position to the destination while having the function of detecting the vehicle position based on the input position data and the coincidence with the road pattern stored in the road map memory, It has a function of automatically calculating the route from the current position of the vehicle to the destination by a computer according to the driver's input for setting the destination.

[0003] In simple terms, this route calculation method divides a road to be calculated into a number of sections, sets the separated points as nodes, sets a vector connecting the nodes as a link, and sets the current position (even at the destination). A node or link closest to the destination (which may be the current position) as a calculation end node or link, and a road stored in the road map memory between them as a calculation end node or link. The map data is read and moved to the work area, all the links are searched in the work area, the link costs of the routes constituting the tree starting from the calculation start node or the link are sequentially added, and the destination or the current position to reach the current position is calculated. This method selects only routes with low link cost (Shibata, Tenmoku, Shimoura "Development of stochastic route search algorithm" Friend electric No. 143, p. 165,1
September 993).

[0004] If a route is calculated by this method, it is possible to reliably reach a destination by traveling along the route without knowing the road. On the other hand, the traffic control center as an organization that manages road traffic information calculates the shortest route from all points in the route providing area to all points at predetermined times, and The route information is transmitted to the on-road beacon located at the location, and the on-road beacon indicates the destination from the vehicle, and when there is a request to provide the route information, the route information is returned to the vehicle. The system is being considered.

According to this system, the traffic control center determines a shortest route reflecting a changing road condition at a predetermined time in consideration of time-varying road traffic information such as traffic jams, accidents, and weather conditions. And the result can be sent to the vehicle through a road beacon.

[0006]

By the way, when the driver
If the user does not like the route previously calculated using the navigation device or the route previously obtained through the route providing system (hereinafter referred to as “initial route”), the driver may run off the route at his own discretion. In this case, since displaying only the initial route is useless, the navigation device determines that the vehicle has deviated from the route, calculates a new route starting from the current position of the vehicle, and indicates it to the driver.

When calculating this new route, for example,
Conventionally, the route calculation is redone from the current position of the vehicle to the destination (Japanese Patent Laid-Open No. 63-163).
210, JP-A-2-141899).
However, in this technique, since the calculation of the shortest route from the current position of the vehicle to the destination is redone, there is a high possibility that the route returning to the initial route is calculated early.

[0008] In this case, the driver is encouraged to follow a route different from his / her own judgment, and thus feels uncomfortable with the navigation device. Therefore, when the driver is traveling off the initial route, it is desirable that the driver can find and display a route that proceeds along the deviated route. Therefore, the present invention does not select a route that returns to the initial route early when the vehicle is running deviating from the initial route, but selects a route that directly proceeds on the deviated route. It is an object of the present invention to provide a navigation device capable of performing guidance based on a route.

[0009]

According to a first aspect of the present invention, there is provided a route guidance apparatus capable of acquiring a plurality of routes to a destination by route acquisition means. A route selecting unit for selecting any one of the plurality of routes acquired by the route acquiring unit, and a deviation determining whether the vehicle is traveling along the route selected by the route selecting unit. When the determination unit and the departure determination unit determine that the vehicle is not traveling along the selected route, a route other than the route selected by the route selection unit is acquired by the route acquisition unit. And if a route other than the route selected by the route selecting means has been acquired, it is determined whether or not there is a route on which the vehicle is traveling. A that travel route determining means, route guiding means, if the path of traveling of the vehicle is to be present by the travel path determination unit, is to induce the driver along the route.

The route acquisition means may be capable of acquiring a plurality of routes to the destination through communication means outside the vehicle (claim 2). The route acquisition means is
By calculating the route to the destination, a plurality of routes may be obtained (claim 3).

[0011]

According to the above arrangement, the driver is guided to travel on any one of the plurality of routes obtained to the destination, but the driver decides on this route at his own discretion. If the vehicle is traveling outside of the selected route, it is checked whether a route other than the selected route has been acquired.If a route other than the selected route has been acquired, It is determined whether or not a traveling route exists, and when it is determined that a traveling route of the vehicle exists, the driver is guided along the traveling route.

[0012] Therefore, the driver can be guided based on a route that immediately follows a route other than the route that returns early to the initial route. In particular, according to the configuration of claim 2, since a plurality of routes to the destination can be acquired through the communication means outside the vehicle, a plurality of routes suitable for the road traffic situation at the time are acquired. be able to.

In particular, according to the third aspect of the present invention, a plurality of routes are acquired by calculating the route to the destination by the vehicle itself. Even if there is a means, even when only traffic regulation information and congestion information are received and route information is not received,
Different routes can be obtained according to the driver's judgment.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In this embodiment, a case will be described in which a vehicle acquires route information from a traffic control center B through a road beacon as a communication means. However, the communication means is not limited to the road beacon, and for example, may be a car phone.

FIG. 2 shows a configuration in which a traffic control center B and a road beacon C are connected by a communication line L, and bidirectional communication by light or radio waves is performed between the road beacon C and the vehicle. More specifically, the road beacon C includes the modem 210, the control device 220, and the transceiver 2
The traffic control center B includes a dedicated map memory 110, a control device 120, a modem 130, and a database 140.

The map-dedicated memory 110 stores data (referred to as link data) relating to links connecting points corresponding to major intersections in the route providing area. The stored link data includes an identification number of each link and points (nodes) corresponding to both ends of the link.
Latitude / longitude, link cost when passing through the link (travel time obtained from the link distance and vehicle traveling speed), link distance, and other incoming links (the previous link) connected to the origin of the link Pointer),
It includes a pointer to another exit link (also referred to as a subsequent link) connected from the end point of the link, a connection cost, and the like.

Note that the connection cost is the cost of turning right or left or going straight to exit from this link and enter the next link. For example, when entry is prohibited, the connection cost is infinite, and when there is a traffic light, the cost takes into account the average signal waiting time when turning right or left or going straight. The above link costs and connection costs (hereinafter collectively referred to as “link costs”) generally use costs when driving at a legal speed. However, if the latest traffic information enters the traffic control center B, the contents may be changed. Changes are made accordingly. For example, when a link is interrupted due to an accident, the link cost of this link is infinite until traffic resumes. If the up lane of a certain road is congested, the cost of the link is increased in accordance with the congestion.

The following two methods are considered as methods for the traffic control center B to obtain the latest traffic information. One is a method in which the traffic control center B knows traffic information by using vehicle detectors installed at various places on the road, a helicopter navigating above the sky, and the like. The other one is the actual value of the travel time of the currently traveling road from the vehicle actually traveling on the road via the road beacon C (until the road beacon C is reached from another road beacon C). Is collected and counted. In the former method, traffic information can be easily collected, but accuracy is reduced. In the latter method, although detailed information is high in accuracy, it takes time for the computer to perform the tallying process.

The control device 120 of the traffic control center B
Focusing on one point in the route providing area, at each time (for example, every 10 minutes) when the latest road traffic information enters the traffic control center B, based on the link cost information at that time, each major intersection link Is calculated (referred to as “reference route tree”), and the calculated reference route tree is stored in the database 140 in the traffic control center B.

Here, a method of searching for a path tree will be described. In the route tree search method according to the present embodiment, one of the links forming the link data of the route providing area is set as the departure point link, and the optimum route tree from the departure point link to all the other links in the same area is determined. This is the procedure for acquiring. Specifically, the route link data stored in the network memory is read and transferred to the work area, and the path is calculated in the work area based on the Dijkstra method or the potential method.

The Dijkstra method or the potential method means that when a path tree is calculated from the current position, a link or a node closest to the current position (hereinafter, referred to as a “link”) is set as a search start link, and a link starting from the search start link is set. This is a method of sequentially adding the costs at the time and constructing a tree of links. The Dijkstra method is
When constructing a tree of links starting from a search start link, when a link branches into a plurality of links, the path cost of each branch link (total sum of costs from the search start link to the link) A method is used in which the magnitudes are compared, rearranged in ascending order of the route cost, and searching is continued from the link having the smallest route cost.

On the other hand, in the potential method, when a certain link branches to a plurality of links, all links are treated equally without comparing the path costs of the links of each branch, and are registered first. The method is to continue searching from the link of the branch that is located. In the Dijkstra method, links have to be rearranged in the order of smaller path costs every time a search is performed. Therefore, the calculation time is spent on it, whereas in the potential method, the processing of rearranging the links is unnecessary. Is short. In the embodiment, the potential method is adopted.

FIG. 3 shows a calculation example of the path tree. (a) is a reference map, and (b) and (c) are examples of respective route trees when starting from one point.
In the route tree of (b), a detour route has occurred because traffic congestion occurred at the time. In the path tree in (c),
Since the time is vacant, no detour has occurred.
Therefore, it can be seen that the form of the path tree changes according to the difference in link cost.

Since there are usually thousands of intersections in the route providing area, the intersections are calculated and stored in the database 140.
Has thousands of reference path trees. Further, the reference route tree is calculated and stored for each one or a combination of season, time zone, month, day of the week, weekday / holiday, time zone, and presence / absence of entertainment during a certain period in the past. This is because the link cost of the link in the route providing area is different for each of these combinations. For example, assuming that season, day of the week, and time are taken, four seasons, seven days of the year, and once every 10 minutes of each hour, the number of reference route trees is (thousands) ) × 4 × 7 × 24 × 6 resulting in a huge number of files.

The file of the reference path tree is referred to when transmitting to the road beacon C. However, not all files are referenced and used. It goes without saying that only the reference route tree starting from the link of the intersection where the on-road beacon C is located is transmitted, but the season, time zone, day of the week, weekday / holiday at the time of the transmission are selected from among them. In addition, the presence / absence of entertainment (these are referred to as “route calculation conditions”) is determined, and only the reference route tree that matches the result of this determination is referred to.

Therefore, when transmitting to the road beacon C, if the conditions are such that there is no Sunday, holiday, and entertainment in the spring morning time zone, every 10 minutes in the same time zone meeting the same route calculation conditions in the past. A total of 25 reference path trees with different calculated times will be referenced. However,
From a practical point of view, if the conditions are too subdivided, the amount of data to be stored in the database 140 becomes enormous, and the control becomes complicated. Therefore, it is preferable to determine the conditions in consideration of economy and efficiency. In the simplest case, it is conceivable to distinguish between two types of holidays and weekdays. Further, since it is conceivable that the situation of midnight on weekdays and the situation of holidays are similar in the downtown area, the holidays and weekdays may not be distinguished from each other, but simply by the time zone.

As described above, the reason why a plurality of reference route trees are transmitted is that the road beacon C calculates a plurality of trees having as much difference as possible for each vehicle and indicates a plurality of routes to the vehicle to select. This is because it is desirable. This is because, if only a similar route to the same destination is shown, it is expected that the selected route will be congested and the destination will not be reached in the shortest time.

The control device 220 of the road beacon C transmits the traffic control center B via the communication line L and the modem 210.
When the data of the path tree transmitted from is received, it is stored in a memory (not shown) in the control device 220. In the road beacon C, when the destination is indicated by the vehicle, the route to the destination is traced by referring to each stored route tree, and the route information is transmitted to the vehicle. The time to trace to this destination is short enough (typically tens of ms
ec) In the road beacon C, after the vehicle indicates the destination, a plurality of routes can be indicated to the vehicle by bidirectional communication while the vehicle is within the communication range of the road beacon C.

Next, the configuration of the vehicle-mounted device will be described.
FIG. 1 is a block diagram showing an in-vehicle navigation device to which the route guidance device of the present invention is applied. The in-vehicle navigation device body 1 includes a CD-ROM, a floppy disk, a mini disk, and the like in which road map data is stored in advance.
A CD drive 2 for reading stored data from a disk D constituted by an IC card or a magneto-optical disk, a display 3 for displaying a map or a vehicle, a joystick remote control key for setting route calculation conditions and the like (hereinafter, "remote control key") 4, a GPS receiver 5, a vehicle speed sensor 6, a direction sensor 7 including a geomagnetic sensor, a gyro, and the like.
Beacon transceiver A etc. are connected.

Further, a controller 16 is provided inside the in-vehicle navigation device body 1, and the controller 16 has a CPU 161 for controlling the control of the device.
(Central processing unit) and SRAM for securing work area
162 and DRAM in which processing programs and the like are stored
163 are provided. Around the controller 16, a memory control unit 11 to which road map data is input from the disk D via the CD drive 2 and a display for outputting the display data to the display 3 for displaying a map or a vehicle. A control unit 12, an input processing unit 13 for inputting a signal from a remote control key 4, a GPS receiver 5 for detecting the position of the vehicle, a direction sensor 6, and a vehicle position detection for inputting direction and vehicle speed information from a vehicle speed sensor 7. The section 14 and a path data receiving section 15 for inputting a path signal from the beacon transceiver A are connected. Signals to each of these processing units,
Alternatively, all signals from each processing unit
Processed by the PU 161.

The CPU 161 includes a route data receiving unit 1
5 When the route to the destination is acquired through
It has a function of selecting the route stored in the RAM 162 and having the shortest travel time or running distance from the stored routes, and displaying the shortest route on the display 3 through the display control unit 12. Then, based on an output signal of the vehicle position detection unit 14, it is determined whether the vehicle is traveling along the shortest route, and if it is determined that the vehicle is not traveling along the shortest route, It is determined whether or not a route other than the shortest route has been acquired. If a route other than the shortest route has been acquired, it is determined whether or not a route on which the vehicle is traveling exists.

If there is a traveling route, the CPU
161 generates display data and voice data for guiding the driver along the route, and guides the driver using these data as the vehicle approaches the intersection. Hereinafter, a schematic control procedure performed by the CPU 161 will be described with reference to flowcharts (see FIGS. 4 and 5).

After starting the system and setting the destination using the remote control key 4, the vehicle is driven. First, it is determined whether or not the destination has been reached (step S1). If not, it is determined whether or not route data has been received from the road beacon C (step S2). When the route data is received, the information of the route and the travel time (the travel time information is also received from the road beacon C) is stored in the SRAM.
162 (step S3).

Then, it is determined whether or not the number of the stored routes is plural (step S4). If the number is plural, the route having the shortest travel time is selected (step S5). At this time, the shortest route distance can be selected. If it is singular, the route is selected as the optimal route (step S6), and if there is more than one, guidance along the route is started while displaying the route.

That is, in step S7, the traveling route is monitored based on the output signal of the vehicle position detector 14, and it is determined whether or not the route deviates from the optimal route (step S9).
If it does not deviate, it is determined whether or not the route data has been received from the road beacon C (step S10). If the route data has been received, the process returns to step S3. Street Beacon C
If no route data has been received, an instruction such as "right turn", "straight ahead", "left turn" or the like is displayed on the display 3 every time the guidance instruction comes (step S11) (step S12). At this time, an announcement such as "Please turn right", "Go straight", "Please turn left", etc. may be made by using an audio device (not shown). Note that the timing of the guidance instruction is, for example, a point in time when the vehicle reaches a predetermined distance before the intersection, which is the end point of the link.

When the vehicle deviates from the optimum route, step S21
Proceeding to (FIG. 5), it is checked whether or not another route is stored in the SRAM 162. If the other route is not stored, the process proceeds to step S23, where it is set that the vehicle has deviated from the route, and the driver is informed of the departure and is warned. At this time, if the in-vehicle navigation device has a route calculation function, the route may be automatically recalculated and displayed on the display 3.

If another route is stored in the SRAM 162, it is checked whether or not the current route is a route on which the vehicle is traveling (step S22). If the route is not the route on which the vehicle is traveling, the process proceeds to step S23, in which the vehicle deviates from the route, and the driver is informed of the departure to call attention, or the in-vehicle navigation device has a route calculation function. Then, the route is automatically recalculated and displayed on the display 3.

If there is a route on which the vehicle is traveling, it is determined whether there are a plurality of routes to the destination (step S).
24) If there is only one route, the route is set as the shortest route, and if there are multiple routes, the shortest route is selected (steps S25 and S2).
6). Then, the shortest route is shown to the driver, and whether guidance along the route is allowed is displayed on the screen or asked by voice (step S27). The reason for asking the driver is to confirm whether the driver intends to travel along the deviated route.

If the driver permits the guidance using the remote control key 4 (step S28), the process returns to step S7 and continues the guidance along the new route. In this way,
When the in-vehicle navigation device obtains one or a plurality of routes, it indicates the shortest route, and when the vehicle deviates from the route, if the vehicle is traveling along another obtained route, the other route is displayed. It was decided to continue guiding along.

Therefore, it is possible to continue instructing a route that proceeds on the deviated route as it is, so that when the driver is deviating from the route indicated first by his / her own intention, the driver passes through the deviated route. When the route information is obtained, the route can be guided according to the driver's intention. The present invention is not limited to the above embodiment. In the above embodiment, the case where the vehicle obtains the route information from the traffic control center B through the road beacon C has been described. However, the vehicle itself calculates a plurality of routes internally, and any of the plurality of routes is used. The present invention can also be applied to a case where guidance is performed based on a sphere.

When the in-vehicle navigation device calculates a route, a road map (highway expressway, city expressway, general national road, main local road, general prefectural road, general prefectural road, or general city of the designated city) stored in the disk D is used. (Including roads and other living roads) is divided into meshes, and link data in which links are stored in units of each mesh is used. In this case, the controller 16 responds to the destination setting signal and the route calculation
From the current location to the destination by referring to the traffic regulation information and traffic congestion information received from the beacon transceiver A, and calculating a plurality of routes from the current location to the destination. .

The above-mentioned "plurality of route calculation conditions" refer to conditions under which a route passing through different links as much as possible and having a similar route cost can be obtained. For example, whether to use an expressway, whether to calculate the shortest time or the shortest distance, whether to select a route that avoids a right turn as much as possible, and the like. These "plurality of route calculation conditions" are also set by the driver using the remote control key 4.

If a plurality of routes are obtained, one of the shortest routes is selected, the route is selected as the optimum route, and guidance along the route is started while displaying the route. If the vehicle deviates from the optimal route, and if the vehicle is traveling on another calculated route at that time, with the driver's permission, the guidance instruction is continued along the other route. In the same manner as in the above-described embodiment, when the driver intentionally deviates from the initially indicated route, and when the route along the deviated route is calculated, the driver's intention is left as it is. Along the route.

Various other changes can be made without changing the gist of the present invention.

[0045]

As described above, according to the route guidance apparatus of the present invention, when the driver is traveling outside the route initially guided by his / her own judgment, another route during the travel of the vehicle is used. Is determined, the driver is guided along the route, so that the driver can proceed on the deviated route without returning to the initial route early.

Therefore, the route can be guided according to the driver's intention. In particular, according to the route guidance apparatus of the second aspect, a plurality of routes to the destination can be acquired through the communication means outside the vehicle. It is possible to guide along a route appropriate to the road traffic situation at the time.

In particular, according to the route guidance apparatus of the third aspect, the vehicle itself calculates a route to the destination to obtain a plurality of routes, so that even when there is no communication means outside the vehicle, According to the driver's preference, different routes can be acquired, so that when the driver proceeds on the deviated route as it is, the driver is guided along the route calculated according to the driver's preference. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an in-vehicle navigation device to which a route guidance device according to the present invention is applied.

FIG. 2 is a diagram showing a configuration in which a traffic control center B and a road beacon C are connected by a communication line L, and bidirectional communication by light or radio waves is performed between the road beacon C and a vehicle.

FIG. 3 shows an example of calculation of a route tree, (a) is a reference map, and (b) and (c) show an example of each route tree when starting from one point.

FIG. 4 is a flowchart illustrating a schematic control procedure for route guidance performed by a CPU 161.

FIG. 5 is a flowchart illustrating a schematic control procedure for route guidance performed by a CPU 161 (continuation of FIG. 4).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Onboard navigation apparatus main body 2 CD drive 3 Display 4 Remote control key 5 GPS receiver 6 Vehicle speed sensor 7 Direction sensor 16 Controller 161 CPU 162 SRAM 163 DRAM 11 Memory control unit 12 Display control unit 13 Input processing unit 14 Vehicle position detection unit 15 Route Data receiving unit 110 Map dedicated memory 120 Control device 130 Modem 140 Database 210 Modem 210 220 Control device 230 Transceiver A Beacon transceiver B Traffic control center C Roadside beacon D Disk L Communication line

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01C 21/00

Claims (3)

(57) [Claims] 1. A route guidance apparatus comprising: route acquisition means for acquiring a route to a destination; and route guidance means for guiding a driver based on the route acquired by the route acquisition means. Is capable of acquiring a plurality of routes to the destination, and a route selecting means for selecting any one of the plurality of routes acquired by the route acquiring means; and Departure determining means for determining whether the vehicle is traveling along the route selected by the route selecting means; and if the departure determining means determines that the vehicle is not traveling along the selected route, It is checked whether or not a route other than the route selected by the route selecting unit has been acquired by the route acquiring unit, and a route other than the route selected by the route selecting unit is checked. When a route is acquired, the traveling route determining means for determining whether or not the vehicle is traveling along the route. A route guidance device for guiding a driver along a route. 2. The route guidance apparatus according to claim 1, wherein said route acquisition means is capable of acquiring a plurality of routes to a destination through communication means outside the vehicle. 3. The route guidance device according to claim 1, wherein said route acquisition means can acquire a plurality of routes by calculating a route to a destination.