JPH0749239A - On-vehicle navigation system - Google Patents

Abstract

PURPOSE:To invite a driver's attention to a safe drive by showing that a curve exists. CONSTITUTION:A travel track calculation means 102 computes the travel track of a vehicle on the basis of the travel speed and direction thereof detected with a vehicle sensor 101. Also, an estimation means 103 estimates the current position of the vehicle on the basis of a travel track and map data 100 detected with the means 102. Furthermore, a display means 103 shows the current position of the vehicle estimated with the means 103 and map data 100 containing the current position. The map data 100 contains the curvature of a road, and a curve judgement means 105 judges that a curve exists, on the basis of the curvature of a road existing in a travel direction and detected with the vehicle sensor 101. Also, a reporting means 106 reports that a curve exists, when the existence thereof is identified with the means 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted navigation system that can prompt a driver to drive safely by displaying that a curve exists.

[0002]

2. Description of the Related Art Conventionally, geomagnetic sensors, gyro sensors,
An in-vehicle navigation system using a vehicle speed sensor or the like is disclosed in Japanese Patent Laid-Open No. 3-257324.

In such an in-vehicle navigation system, the map data has a structure as shown in FIG. That is, as shown in FIG. 3, a road is divided into a plurality of lines (links) by points (nodes), and each link is represented by a start point, an end point, and one or more interpolation points between the start point and the end point. Has been done.

[0004]

However, in the conventional map data, since each link is represented by a start point, an end point, and one or more interpolation points between the start point and the end point,
When the road is curved, the shape of the curve is known, but since the curvature of the link is not included, it is not known how much the curve has. In order to obtain the curvature of the link, it has to be calculated, and since this calculation is complicated, conventionally, it was not possible to immediately obtain the curvature of the link at a necessary time.

If the curvature of the link can be immediately obtained, for example, if the curvature of the link existing ahead of the current position of the vehicle is larger than a predetermined value, the driver is informed that there is a curve. Can be notified, and in addition,
Based on the curvature of the curve, it is possible to quickly determine whether or not the curve can be turned at the current vehicle speed,
When it is determined that the driver cannot turn completely, it becomes possible to notify the driver that deceleration is necessary.

Therefore, an object of the present invention is to provide an in-vehicle navigation system that stores the curvature of a road and uses the curvature to prompt a driver to drive safely.

[0007]

In order to achieve the above object, the present invention, as shown in FIG. 1, includes map data 100 including at least a plurality of link data indicating the shape of a road.
A vehicle sensor 101 for detecting at least the speed and the traveling direction of the vehicle; a traveling locus calculation means 102 for calculating the traveling locus of the vehicle based on the vehicle speed and the traveling direction detected by the vehicle sensor 101; Estimating means 103 for estimating the current position of the vehicle based on the traveling locus calculated by the means 102 and the map data 100.
And a display unit 1 for displaying the current position estimated by the estimating unit 103 and the map data 100 including the current position.
In an in-vehicle navigation system having 04 and
The map data 100 includes the curvature of the road corresponding to the link data for each link data, and the vehicle sensor 101 from the current position estimated by the estimation means 103.
A curve determining means 10 for determining that a curve exists based on the curvature of the road existing in the traveling direction detected by
5 and the notifying means 106 for notifying that the curve exists when the curve judging means 105 judges that the curve exists.

Further, for each of the link data, the curvature of the road corresponding to the link data is calculated and added to the link data to convert the map data, and the present time estimated by the estimating means 103. Based on the curvature of the road existing in the traveling direction detected by the vehicle sensor 101 from the position, the curve determination unit 105 determines that a curve exists, and when the curve determination unit 105 determines that a curve exists, the curve is determined to be a curve. You may make it have the notification means 106 which notifies that it exists.

It should be noted that the notifying means 106 makes a notification by display or voice that the curve exists.

Further, when a curve is determined by the curvature calculating means for calculating the curvature of the road on which the vehicle can turn at the vehicle speed detected by the vehicle sensor 101 and the curve determining means 105, the curve is calculated. Further comprises a comparing means for comparing the curvature of the curve with the curvature calculated by the curvature calculating means, and the notifying means 106 makes comparison by the comparing means when the curve judging means 105 judges that a curve exists. As a result, if the curvature of the curve is equal to or larger than the curvature calculated by the curvature calculating means, it may be displayed that the deceleration is necessary in addition to the existence of the curve.

It should be noted that a weather sensor for detecting the temperature and weather of the outside air, and a friction coefficient calculating means for calculating a friction coefficient indicating the slipperiness of a road surface based on the temperature and weather detected by the weather sensor, Braking distance calculating means for calculating the braking distance from when the vehicle is instructed to stop until the vehicle actually stops based on the friction coefficient calculated by the friction coefficient calculating means and the vehicle speed detected by the vehicle sensor 101. May be further provided. In this case, the curve determination means 105 determines the vehicle sensor 101 based on the current position estimated by the estimation means 103.
Among the roads existing in the traveling direction detected by the above, it is determined that there is a curve when the curvature of the road existing ahead of the braking distance calculated by the braking distance calculating means is larger than a predetermined value. Can be

[0012]

In the present invention, since the map data includes the curvature of the road, the map data need not be calculated.
Since the curvature can be quickly acquired, the driver can be notified that the curve exists.

Further, when a curve exists,
Based on the curvature of the curve, it is possible to quickly determine whether or not the curve can be turned at the current vehicle speed,
If it is determined that the driver cannot turn completely, the driver can be notified that deceleration is necessary.

Therefore, the driver can be encouraged to drive safely.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of an on-vehicle navigation system according to an embodiment of the present invention.

In the figure, 200 is a temperature sensor, 201 is a raindrop sensor, 202 is a vehicle speed sensor, 203 is a geomagnetic sensor,
Reference numeral 204 is a gyro sensor, 205 is a memory, 206 is a touch switch, 207 is a voice output unit, 208 is a CPU,
209 is a CRT, 210 is a CD-ROM, and 211 is a cursor key switch.

In FIG. 2, a temperature sensor 200 detects the temperature of the outside air, and a raindrop sensor 201 detects whether it is raining or snowing (weather). In addition, the vehicle speed sensor 20
2 detects the speed of the vehicle, and the geomagnetic sensor 203 and the gyro sensor 204 detect the traveling direction of the vehicle.

The CD-ROM 210 is for storing map data.

In this embodiment, the map data is shown in FIG.
The configuration is as shown in. That is, as in the conventional case, as shown in FIG. 3, a road is divided into a plurality of links by nodes, and each link is represented by a start point, an end point, and one or more interpolation points between the start point and the end point. However, in the present embodiment, the curvature of the link is further included.

The touch switch 206 and the cursor key switch 211 are used by the driver to input various instructions.

The CPU 205 also controls the vehicle speed sensor 202.
By calculating the traveling locus of the vehicle based on the vehicle speed detected by the vehicle and the traveling direction detected by the geomagnetic sensor 203 and the gyro sensor 204, and performing matching processing between the calculated traveling locus and map data, the vehicle Current position is estimated, and the estimated current position and map data including the current position are displayed on the CRT 209.

In this embodiment, the curvature of the link included in the map data is used to notify the driver that there is a curve, and the curve can be completely turned at the current vehicle speed. If the driver does not need to decelerate the vehicle, the driver is notified that the vehicle needs to be decelerated so that the driver can be encouraged to drive safely.

The operation of this embodiment for prompting the driver to drive safely will be described below with reference to the processing flowchart of FIG.

FIG. 6 is a processing flowchart showing the operation of this embodiment.

As shown in FIG. 6, first, the temperature sensor 20
The temperature detected by 0 and the weather detected by the raindrop sensor 201 are acquired (step 600), and the friction coefficient indicating the slipperiness of the road surface under the current weather conditions is calculated based on the acquired temperature and weather (step 600). Step 6
01).

In step 601, if the temperature is higher than a predetermined value and there is no rain or snow, it can be determined that the road surface is not slippery, and even if the temperature is higher than the predetermined value. If it is raining or snowing, it can be judged that the road surface is slippery. If the temperature is lower than a predetermined value and it is raining or snowing, the road surface may be frozen, and it can be determined that the road surface is more slippery.

Subsequently, the vehicle speed detected by the vehicle speed sensor 202 is acquired (step 601), and step 60
Based on the friction coefficient calculated in 1 and the vehicle speed acquired in step 602, a braking distance that allows the driver to safely stop the vehicle is calculated (step 603).

In step 603, the braking distance corresponding to the friction coefficient and the vehicle speed may be stored in advance in the memory 205 as a table, and the braking distance may be calculated based on this table.
The braking distance may be calculated by substituting the friction coefficient and the vehicle speed into the calculation formula stored in FIG.

Then, at the vehicle speed obtained in step 602, the curvature of the road that can be turned without exceeding the center line of the road is calculated (step 60).
4).

Next, based on the map data stored in the CD-ROM 210, among the links existing in the traveling direction from the current position of the vehicle, the links existing ahead by the braking distance calculated in step 603 are curved. Is determined (step 605).

In step 605, when the curvature of the link is larger than a predetermined value, it is determined to be a curve. Moreover, the map data may include only a curvature larger than a predetermined value. In this case, only the braking distance calculated in step 603 is selected from the links existing in the traveling direction from the current position of the vehicle. If the previously existing link includes a curvature, it is determined to be a curve. Further, it may be determined whether or not the link existing ahead by the braking distance + the predetermined distance is a curve instead of the link existing ahead by the braking distance.

Since the braking distance is a distance in consideration of the current weather conditions and the current vehicle speed, the braking distance can be used for judging the existence of a curve, so that it is possible to cope with an environment which is constantly changing. For example, if the vehicle speed is 4
In the case of 0 Km / h and the case of 60 Km / h, the positions to be decelerated are different in order to enter the same curve at the same vehicle speed even under the same weather condition. That is, when the vehicle speed is 60 Km / h, the position to be decelerated is closer to the front when the vehicle speed is 60 Km / h. Also, for example, in the case where it is not raining or snowing and when it is falling, even if the vehicle speed is the same, the latter is more slippery on the road surface, so in order to enter the same curve at the same vehicle speed, The position to decelerate is different. That is, the position to decelerate is closer to the front when the rain or snow is falling than when it is not raining or snowing.

If it is determined in step 605 that the curve is not a curve, the process returns to step 601, and if it is determined that it is a curve, the curvature of the curve is acquired from the map data (step 606), and the acquired curvature and step 604 are acquired. The calculated curvature is compared (step 607).

If the curvature calculated in step 604 is smaller than the curvature acquired in step 606, the fact that a curve exists is displayed on the CRT 209 (step 608) and the process returns to step 601.

In step 608, the fact that a curve exists is displayed on the CRT 209. However, in addition to the display or instead of the display, a sound indicating that the curve exists is output from the audio output unit 207. You may do it.

If the curvature calculated in step 604 is greater than or equal to the curvature acquired in step 606, the fact that a curve exists is displayed on the CRT 209, and the curve cannot be bent at the current vehicle speed. A message indicating that it is necessary is displayed on the CRT 209 (step 60).
9).

FIG. 7 shows an example of a display screen of the CRT 209 at this time.

In FIG. 7, on the display screen of the CRT 209, in addition to the display of the map data showing the shape of the road, "there is a curve ahead", "the approach speed has been decelerated"
Is displayed.

In step 609, the fact that there is a curve and the fact that deceleration is required are displayed on the CRT 209. However, in addition to or instead of the display,
A voice indicating that there is a curve and that deceleration is necessary may be output from the voice output unit 207. In addition, the fact that a curve exists is displayed on the CRT 209, and a voice indicating that deceleration is required is output by the voice output unit 20.
You may make it output from 7.

The process shown in FIG. 6 is started from the time when the on-vehicle navigation system is started, and thereafter, it is periodically started until the on-vehicle navigation system goes down. However, it is preferable that the cycle in which this process is activated be as short as possible.
In addition, after executing step 209, the process may return to step 601 and, once activated, may loop until the in-vehicle navigation system goes down.

As described above, according to the present embodiment, it is determined whether or not a curve exists based on the curvature of the link included in the map data. It is possible to notify the driver that the vehicle is present. Further, based on the road surface condition and the current vehicle speed, it is determined whether or not the curve can be turned. If it is determined that the curve cannot be turned, in addition to the fact that the curve exists, Since the vehicle cannot turn through the curve, it is possible to notify the driver that deceleration is necessary.

A conventional conversion tool for converting the conventional map data having the structure shown in FIG. 4 into the map data of this embodiment having the structure shown in FIG. 5 may be provided. This conversion tool calculates the curvature of the link for each link by calculation and adds the calculated curvature to the link. By using this conversion tool, even if the conventional map data is used, Since the map data can be converted into the example map data, the above-described operation becomes possible.

Further, in the embodiment, the traveling locus of the vehicle is calculated based on the vehicle speed and the traveling direction, and the present traveling position of the vehicle is estimated by performing the matching process between the calculated traveling locus and the map data. However, an in-vehicle navigation system that calculates the current position of the vehicle based on the information from the satellite may be used.

[0045]

As described above, according to the present invention,
Since the map data includes the curvature of the road, the curvature can be promptly acquired without calculation by calculation, so that the driver can be notified that the curve exists.

Further, when a curve exists,
Based on the curvature of the curve, it is possible to quickly determine whether or not the curve can be turned at the current vehicle speed,
If it is determined that the driver cannot turn completely, the driver can be notified that deceleration is necessary.

Therefore, there is an effect that the driver can be encouraged to drive safely.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of a vehicle-mounted navigation system according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of conventional map data.

FIG. 4 is a configuration diagram of conventional map data.

FIG. 5 is a configuration diagram of map data according to this embodiment.

FIG. 6 is a processing flowchart showing the operation of the present embodiment.

FIG. 7 is an explanatory diagram showing an example of a display screen of a CRT displaying that a curve exists and that deceleration is required.

[Explanation of symbols]

Reference numeral 100 ... Map data, 101 ... Vehicle sensor, 102 ... Traveling locus calculation means, 103 ... Estimation means, 104 ... Display means, 105 ... Curve determination means, 106 ... Notification means, 20
0 ... Temperature sensor, 201 ... Raindrop sensor, 202 ... Vehicle speed sensor, 203 ... Geomagnetic sensor, 204 ... Gyro sensor, 205 ... Memory, 206 ... Touch switch, 207
... voice output unit, 208 ... CPU, 209 ... CRT, 21
0 ... CD-ROM, 211 ... Cursor key switch.

Claims (5)

[Claims] 1. A map data including at least a plurality of link data indicating a shape of a road, a vehicle sensor for detecting at least a speed and a traveling direction of a vehicle, and a vehicle speed and a traveling direction detected by the vehicle sensor. A traveling locus calculating means for calculating a traveling locus of the vehicle, an estimating means for estimating the current position of the vehicle based on the traveling locus calculated by the traveling locus calculating means and the map data, and an estimation by the estimating means. In a vehicle-mounted navigation system having a displayed current position and display means for displaying map data including the current position, the map data includes, for each of the link data, a curvature of a road corresponding to the link data, Road existing in the traveling direction detected by the vehicle sensor from the current position estimated by the estimation means And a notifying means for notifying that the curve exists if the curve judging means judges that the curve exists. In-vehicle navigation system. 2. A map data including at least a plurality of link data indicating a shape of a road, a vehicle sensor for detecting at least a speed and a traveling direction of a vehicle, and a vehicle speed and a traveling direction detected by the vehicle sensor. A traveling locus calculating means for calculating a traveling locus of the vehicle, an estimating means for estimating the current position of the vehicle based on the traveling locus calculated by the traveling locus calculating means and the map data, and an estimation by the estimating means. In a vehicle-mounted navigation system having a displayed current position and display means for displaying map data including the current position, a curvature of a road corresponding to the link data is calculated for each link data, and the curvature is added to the link data. The conversion means for converting the map data, and the vehicle from the current position estimated by the estimation means. Based on the curvature of the road existing in the traveling direction detected by both sensors, the curve determination means for determining that a curve exists, and when it is determined that the curve exists by the curve determination means,
An in-vehicle navigation system, comprising: a notification unit that notifies that a curve exists. 3. The in-vehicle navigation system according to claim 1 or 2, wherein the notification means displays and / or indicates that a curve exists.
Alternatively, an in-vehicle navigation system characterized by notifying by voice. 4. The on-vehicle navigation system according to claim 1, 2, or 3, and a curvature calculating means for calculating a curvature of a road on which the vehicle can turn at the vehicle speed detected by the vehicle sensor,
And a comparing means for comparing the curvature of the curve with the curvature calculated by the curvature calculating means when the curve judging means judges that the curve exists, and the notifying means is characterized by the curve judging means. When it is determined that a curve exists, if the result of comparison by the comparison means is that the curvature of the curve is greater than or equal to the curvature calculated by the curvature calculation means, deceleration is necessary in addition to the fact that there is a curve. An in-vehicle navigation system, which notifies that there is. 5. The in-vehicle navigation system according to claim 1, 2, 3 or 4, wherein a weather sensor for detecting the temperature and weather of the outside air, and the temperature and weather detected by the weather sensor are used.
Based on the friction coefficient calculation means for calculating the friction coefficient indicating the slipperiness of the road surface, the friction coefficient calculated by the friction coefficient calculation means and the vehicle speed detected by the vehicle sensor, an instruction to stop the vehicle is given. And a braking distance calculating means for calculating a braking distance until the vehicle actually stops, the curve determining means is configured to detect the braking distance from the current position estimated by the estimating means in the traveling direction detected by the vehicle sensor. Among the existing roads, an in-vehicle navigation system characterized by determining that a curve exists when the curvature of the road existing ahead of the braking distance calculated by the braking distance calculating means is larger than a predetermined value. .