JP2982709B2 - Intersection 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 navigation device mounted on a vehicle and used for guidance of an intersection.

[0002]

2. Description of the Related Art Conventionally, an in-vehicle navigation device has been used to assist a vehicle traveling on an unfamiliar land. The in-vehicle navigation device includes, for example, a direction sensor, a distance sensor, a GPS receiver, a road map memory, a computer, and the like. The direction data input from the direction sensor, the traveling distance data input from the distance sensor, and the GPS reception are provided. It has a function to detect the vehicle position based on the position data input from the machine.

Further, such a navigation device may be provided with a route calculation function for automatically calculating a route from the current position of the vehicle to the destination by a computer in accordance with a destination setting input by a passenger. is there. If this function is used, it is possible to reliably reach the destination by traveling along the calculated route without knowing the road to the destination.

[0004]

By the way, the apparatus for calculating the recommended route as described above can guide the route of the vehicle at the intersection when the vehicle approaches the main intersection on the recommended route. The technique is disclosed in Japanese Patent Application Laid-Open No. 7-103776. The technology disclosed in the above publication outputs a voice such as "Please turn right at the second intersection" or "Turn left at the intersection 300m ahead" to provide guidance on the course of the vehicle at the intersection.

[0005] However, there are cases where intersections other than straight-ahead intersections that are subject to route guidance continue for an extremely short distance. For example, it is assumed that there is an intersection to be turned left on the recommended route to be traveled, and an intersection to be turned right after that. In this case, if the former intersection is called a "first intersection" and the latter intersection is called a "second intersection", if the distance between both intersections is short (for example, 5
0 m or less), after passing the first intersection, the distance to the second intersection is short and time is not enough, so that guidance of the second intersection may not be possible.

In this case, it is conceivable that when guiding at the first intersection, guidance at the second intersection is also performed. For example, "Please turn left at the intersection 200m ahead, then turn right immediately."
However, usually, drivers and passengers (hereinafter collectively abbreviated as "drivers") do not always listen carefully to the intersection guidance message to the end, and even if they listen to the end, they are nervous about turning at the first intersection. And then forget how to drive.

[0007] Therefore, the present invention provides a method for controlling a vehicle in a case where two guide intersections are close to each other and continuous, even after the first intersection.
It is an object of the present invention to provide an intersection guidance device that can convey guidance contents to a driver with a minimum number of words according to a distance from a first intersection to a second intersection.

[0008]

SUMMARY OF THE INVENTION An intersection guidance device according to the present invention is used when a vehicle travels along a preset route.
A guidance target intersection determining means for determining a guidance target intersection on a route, a distance calculation means for calculating a distance d between an intersection that has just passed and the next guidance target intersection, and a travel time required to reach the guidance target intersection. The present invention includes a travel time predicting means for predicting based on the distance d, and a guide content determining means for determining a content capable of voice guidance in the travel time predicted by the travel time predicting means (claim 1).

According to the above configuration, even when the two guidance intersections are close to each other and continuous, after the first intersection is turned, the travel time from the first intersection to the second intersection is determined by the distance d. By changing the content of the voice guidance according to the travel time, the guidance content can be accurately transmitted to the driver after the first intersection is turned.

It is preferable that the travel time prediction means predicts a travel time to reach the guidance target intersection based on the distance d and a standard traveling speed of the road (claim 2). It is further preferable to predict the travel time until the vehicle travels on the basis of the distance d, the standard travel speed of the road, and the actual travel speed of the vehicle (claim 3).

In this way, it is possible to accurately predict the traveling time required to reach the guidance target intersection. The “standard traveling speed of the road” is a speed that is empirically determined from the road width and the number of lanes. The “contents that can be voice-guided during the predicted travel time” are:
The shorter the traveling time, the more the word is omitted (claim 5).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a configuration of an intersection guidance device applied to a navigation device. This intersection guidance device includes a position detection unit 5 that detects a traveling position of the vehicle by a distance sensor 1 and a direction sensor 2 that detect a moving amount and a change in direction of the vehicle, respectively.

The position detector 5 calculates the current position data of the vehicle at predetermined intervals by so-called self-contained navigation based on the vehicle movement data and the heading change data output from the sensors 1 and 2. Further, the position detection unit 5 calculates a traveling locus by connecting the current position data of the vehicle,
It has a function of correcting the position of a vehicle based on a comparison between a traveling locus and road data stored in a disk D described later (so-called map matching method; Japanese Patent Application Laid-Open No. 64-42).
No. 000).

Note that the current position of the vehicle is detected by the GPS receiver 4 connected to the position detecting unit 5.
A GPS navigation system in which a radio wave transmitted from the S satellite is received by the GPS receiver 4 via the GPS antenna 3 and the position of the vehicle is detected based on the propagation delay time of the radio wave may be applied. Further, the current position of the vehicle obtained by the self-contained navigation may be corrected based on the current position of the vehicle obtained by the GPS navigation (see Japanese Patent Publication No. 7-92388).

The current position data of the vehicle detected by the position detector 5 is given to the controller 6. The control unit 6 functions as a control center of the navigation device.
PU 61, RAM 62, route calculating unit 63 for calculating a recommended route, traveling monitoring unit 64 for monitoring whether a vehicle has deviated from the recommended route, and route guiding unit 65 for searching for an intersection to be guided on the recommended route. And non-volatile memory 66
And so on.

When various calculation conditions such as a destination are input from the remote control key 10, the route calculation unit 63 stores the input destination data and the like in the RAM 62,
Route calculation road map data (described later) is read from a disk D described later. Then, the route calculation unit 63 performs a route search starting from the current position detected by the position detection unit 5 using, for example, the Dijkstra method or the potential method, and acquires a recommended route to the destination.

The control unit 6 is connected to a man-machine interface unit 8 for controlling an interface with a driver. In the man-machine interface section 8,
For example, a display device 9 having a display screen composed of a liquid crystal display element, a CRT, a plasma element, or the like, a remote control key 10 composed of, for example, a joystick remote control key for inputting a request for route calculation, etc. Is output as a voice.

The control unit 6 includes, for example, a CD-RO
M, a disk control unit 7 to which a disk D composed of a magneto-optical disk or the like is loaded is connected. Disk D
Is used to divide a road map (including highway national roads, motorways, general national roads, prefectural roads, city roads of designated cities, and other living roads) into a mesh shape. Alternatively, it stores road map data for position detection, road map data for route calculation, and the like, which are composed of a combination of a node corresponding to a bending point or the like and a link connecting the nodes.

Here, the "node" is generally a coordinate position for specifying a road intersection or a turning point.
A node representing an intersection is referred to as an intersection node, and a node representing a road bending point (excluding an intersection) is referred to as an interpolation point node. The vector connecting the nodes is a "link". The link data includes a link number, a pointer to a link start node and a pointer to a link end node, a link distance,
Link direction, required time in that direction, type or type of road, road width, number of lanes, one-way, no right turn,
Includes data on left turn prohibition and toll roads.

As described above, since the pointer to the start node of the link and the pointer to the end node of the link are included in the link data, the point can be specified by only the node or only the link. When the start point of a link is specified by a link, the link is called an “exit link”, and when the end point of the link is specified, the link is called an “entry link”. Further, since the link data includes the direction in which the vehicle passes through the link, by specifying one link, the traveling direction of the vehicle can also be specified. FIG. 2 illustrates four exit links that specify an intersection (crossroad), and FIG. 3 illustrates four approach links that specify an intersection (crossroad).

The disk D stores a voice guidance table as shown in Table 1 which stores voice guidance contents when outputting route guidance at an intersection by voice.

[0022]

[Table 1]

This voice guidance table is provided with columns of "utterance phase number sequence", "maximum utterance time", and "contents of voice guidance". The “utterance phase number sequence” is a number assigned according to the voice guidance content. "Maximum utterance time" is the time required to finish speaking the voice guidance content. As the “voice guidance contents”, various contents are prepared according to the maximum utterance time. For example, the maximum utterance time is 4
In the case of seconds, the complete sentence is "Please turn right (left) about xxm ahead", but the shorter the maximum utterance time is, the more the omission is made. (Left). "

When the current position data of the vehicle is given from the position detection unit 5, the control unit 6 drives the disk control unit 7 to output road map data around the current position of the vehicle to the disk D via the disk control unit 7. Read from Thereafter, display data is created based on the read road map data and the current position data of the vehicle, and the display data is given to the display device 9 via the man-machine interface unit 8. The position is displayed together with the road map by a car mark.

Further, the controller 6 superimposes the recommended route calculated by the route calculator 63 on the road map displayed on the display device 9. At the same time, the control unit 6
Specifies an intersection to be guided along the recommended route (an intersection excluding a straight-ahead intersection; hereinafter, referred to as a “guided intersection”), and stores information on the guided intersection in the nonvolatile memory 66. Is stored in the passing intersection table as shown in Table 2.

[0026]

[Table 2]

The passing intersection table has columns for "entry link number", "intersection interval", "branch direction", "road width", "maximum speed", and "intersection coordinates". Hereinafter, the recommended route and the guidance target intersection will be described with reference to FIG. In FIG. 4, the guidance target intersections A and B exist on the recommended route indicated by the broken line.

Focusing on the guidance target intersection B,
In this passing intersection table, the guidance target
The difference B is specified by the end point of the approach link. Approach
A link identifies the intersection by its end point
Be able to enter the intersection as mentioned above
This is because the direction can be specified. "Between intersections
In the column of "distance", the link distance d of the incoming link_TwoIs stored
You. In the "Branch direction" column, enter the direction of the incoming link,
Angle difference θ from the exit link direction leading to the link end point
_TwoIs stored. In the "Road width" column, the road of the approach link
Width D _TwoIs stored. In the "intersection coordinates" column,
The coordinates of the elephant intersection B (x_Two, Y _Two) Is stored. "maximum
Speed ”indicates that the link traveling speed for traveling on the approach link is
Is stored. Here, the “link traveling speed” refers to the road concerned.
Means the standard driving speed of the vehicle.
The speed may be regulated based on road width and the number of lanes.
The speed may be determined as the speed. Empirically from the road width
Table 3 shows a specific example when the speed is determined.

[0029]

[Table 3]

FIGS. 5 and 6 are flowcharts showing the control processing of the intersection guidance device. This flowchart predicts the time to reach the next guidance target intersection,
This represents a control process for changing the voice content to be guided according to the time. First, when a destination is input by an operation of the remote control key 10 of the driver, the route calculation unit 63 performs a route search process (step S1). When the recommended route to the destination is determined (step S2), the CP
U61 searches for a guidance target intersection on the recommended route and creates a passing intersection table (step S3).

When the current position is updated (step S4), the CPU 61 specifies the next guidance intersection by referring to the passing intersection table, and calculates the distance d from the passed intersection to the guidance intersection (step S4). S5). next,
The CPU 61 determines whether or not the distance d to the guidance intersection is a fixed distance, for example, 50 m or less (step S).
6). If the distance is not less than 50 m, the process proceeds to step S7, and the intersection guidance with the usual content is performed once. Intersection guidance with normal content is, for example, content such as "Please turn right at the intersection at $ m".

If it is 50 m or less, the CPU 61 obtains the actual traveling speed of the vehicle from the position detecting section 5 (step S5).
8) The time to reach the guidance intersection is calculated (step S9). A method of calculating the time required to reach the guidance intersection will be described with reference to FIG. The distance from the intersection just passed to the guidance intersection is d, and the vehicle is at the current speed v (t; t = 0)
(Hereinafter referred to as “v (0)”). In this case, the time required for the vehicle to reach the guidance intersection is not necessarily d.
/ V (0). This is because the vehicle does not always maintain the speed v (0), and it is predicted that the vehicle will decelerate as it approaches the guidance intersection.

In the above, when the speed v (0) is lower than the link traveling speed, it is considered that the vehicle accidentally reached the speed v (0) during acceleration. In this case, the acceleration is continued until the link traveling speed of the approach link is reached. FIG. 7A shows the state of the time change of the speed v (t) in this case. The vehicle accelerates from the current speed v (0), reaches the link traveling speed, maintains the link traveling speed for a while, and decelerates to a predetermined speed when approaching the guidance intersection. This deceleration rate assumes a constant value. In the graph of FIG. 7A, the value ∫v (t) dt obtained by integrating the speed v (t) with respect to time from t = 0 to t = T represents the traveling distance, and this is the distance d to the guidance intersection.
A time T that is equal to

Whether the speed v (0) is equal to the link traveling speed,
If it is greater, the vehicle will maintain this speed v (0). FIG. 7B shows the state of the time change of the speed v (t) in this case. The vehicle maintains the current speed v (0) and decelerates when approaching the guidance intersection. In the graph of FIG. 7B, the value ∫v (t) dt obtained by integrating the speed v (t) with respect to time from t = 0 to t = T represents the traveling distance, and this is the distance d to the guidance intersection.
A time T that is equal to

Since the above-described integral calculation becomes complicated, if it is desired to perform the calculation more simply, the time T required for the vehicle to reach the guidance intersection may be obtained by d / v (0). Returning to FIG. 5, in step S10, an utterance phase number that can be provided within the determined time T is acquired via the disk control unit 7, and in step S11, the intersection guidance is provided using the voice guidance content corresponding to the utterance phase number. do.
In this case, it goes without saying that whether to make a right turn or a left turn is determined based on the sign of the branch direction θ stored in the passing intersection table.

As described above, when the distance d to the guidance intersection is long, the intersection guidance with the normal content is performed. However, when the distance to the guidance intersection becomes short, there is no time for the guidance with the intersection at the normal content. The time to reach the guidance intersection is predicted according to the distance d to the guidance intersection and the current speed v (0) of the vehicle, and guidance contents that can be spoken within that time are selected and guided.

When the voice guidance is completed, it is determined whether or not the vehicle has passed the guidance intersection (step S12), and if it has passed, it is determined whether or not there is a next route link (step S12).
14) If there is a next route link, the guidance intersection is updated for the next guidance (step S16), and the process returns to step S3. If there is no next route link, destination arrival guidance is provided (step S15).

Although the embodiment has been described above, the present invention is not limited to the above-described embodiment.
Various changes can be made within the scope of the invention described in the claims.

[0039]

As described above, according to the intersection guide device of the first aspect, when two guide intersections are close to each other and are continuous, even after the first intersection is turned, the second intersection is connected to the second intersection. By changing the content of voice guidance according to the distance to the driver, the minimum guidance content can be transmitted to the driver, and the driver can travel along the route without erroneous intersections to be turned.

According to the intersection guide device of the second or third aspect, it is possible to accurately predict the travel time required to reach the guidance target intersection. If the standard traveling speed of the road is a speed empirically determined from the width of the road and the number of lanes, the standard traveling speed can be uniformly determined. Assuming that the content that can be voice-guided in the predicted travel time is such that words are omitted as the travel time is shorter, the minimum necessary information is transmitted even within a limited time. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an intersection guidance device according to the present invention.

FIG. 2 is a diagram illustrating an example of an exit link at an intersection.

FIG. 3 is a diagram illustrating an example of an approach link at an intersection.

FIG. 4 is a diagram illustrating a positional relationship between a guidance target intersection and a road connected to the intersection;

FIG. 5 is a flowchart showing a control procedure of the intersection guidance device of the present invention.

FIG. 6 is a flowchart (continuation of FIG. 5) showing a control procedure of the intersection guidance device of the present invention.

FIG. 7 is a diagram for explaining a method of calculating a traveling time up to a guidance intersection.

[Explanation of symbols]

 Reference Signs List 5 position detection unit 6 control unit 7 disk control unit 8 man-machine interface unit 9 display device 10 remote control key 11 sound output device 61 CPU 62 RAM 63 route calculation unit 64 running monitoring unit 65 route guidance unit 66 nonvolatile memory D disk

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01C 21/00 G08G 1/0962-1-0969 G09B 29/10

Claims (5)

(57) [Claims] An intersection guidance device that performs voice route guidance when a vehicle approaches a guidance target intersection, wherein the guidance target intersection on the route is determined when the vehicle travels along a preset route. The guidance target intersection determining means to be determined, and the distance d between the just-passed intersection and the next guidance target intersection
And a travel time required to reach the guidance target intersection is calculated as the distance d.
An intersection guidance device, comprising: a travel time prediction unit that predicts the content based on the travel time; and a guidance content determination unit that determines the content that can provide voice guidance in the travel time predicted by the travel time prediction device. 2. The intersection according to claim 1, wherein said traveling time prediction means predicts a traveling time to reach said guidance target intersection based on said distance d and a standard traveling speed of said road. Guide device. 3. The travel time predicting means predicts a travel time to reach the guidance target intersection based on the distance d, a standard travel speed of the road, and an actual travel speed of the vehicle. The intersection guidance device according to claim 1. 4. The intersection guidance device according to claim 2, wherein the “standard traveling speed of the road” is a speed empirically determined from a road width or the number of lanes. 5. The intersection guidance device according to claim 1, wherein the words "contents that can be voice-guided during the predicted travel time" are such that the shorter the travel time, the more the words are omitted.