JP3503462B2 - Curve detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a device for detecting a curve based on map data provided in a navigation device, and particularly to a curve detection using point data for route search and map drawing included in the map data. Regarding the device.

[0002]

2. Description of the Related Art Some vehicle control devices that change driving force characteristics and the like according to road conditions are equipped with a curve detection device. When a curve is detected on the route of the vehicle, the engine brake is increased. Corrections have been made to improve safety and driving performance when driving on curves.

There are several methods for detecting a curve by such a curve detecting device. When detecting a curve based on map data provided in a navigation device,
There is a method of using point data (node points and interpolation points arranged between the node points) used for route search and map drawing included in the map data. For example, JP-A-8-1
In the device disclosed in No. 94893, the curve detecting means 2
Curve 0 is used to detect the curve by using the point data included in the map data.

To briefly explain this, FIG. 7 shows the processing in the curve detecting means 20. When determining whether the curve detecting point B is a curve, the curve detecting point B is determined.
From the point A before the sampling distance L and the point C ahead by the sampling distance L to the vector AB and the vector BC
Is calculated as the curvature index θ at the detection point B, and when the curvature index θ is larger than the curve judgment reference index θ0, it is determined to be a curve, and conversely, when it is smaller than the reference index θ0, it is a straight road. Making a decision.

[0005]

[Problems to be solved by the invention] However,
Since the actual point data included in the map data of the navigation device are not arranged at equal intervals, the conventional curve detection method in which the sampling distance L is set to an integer multiple of the pitch interval (10 m) is used as it is. I couldn't.

In addition, points less than the sampling distance L (see FIG.
In this case, it is difficult to detect a curve that matches the actual road shape because all points between AB and BC are ignored. Especially, if the sampling distance L is increased, a small curve or curve start point can be detected correctly. There was a problem of disappearing.

Further, the distance required for the driver to recognize the road shape changes depending on the vehicle speed.
Since L was determined irrespective of the vehicle speed, it was difficult to detect the curve that matches the driver's feeling.

As described above, if the point data arranged at unequal intervals cannot be used, the map data of the navigation device cannot be used as they are, and if the curve detection device cannot detect the curve correctly, Naturally, it becomes difficult for a driving force control device, etc. that performs control based on the output result to perform control that matches the actual road conditions and the driver's sense, which may cause the driver to feel uncomfortable and anxious. Will end up.

The present invention has been made in view of the above problems, and it is possible to detect a curve by using point data arranged at unequal intervals, and further, a curve detecting apparatus that can correctly detect a curve. The purpose is to provide.

[0010]

According to a first aspect of the present invention, a refraction angle of a link connecting points on a vehicle route is calculated from point data included in map data of a navigation device, and the refraction angle of the link is used as a basis. In the curve detection device that performs curve detection, one of the point data arranged on the vehicle route is set as the curve detection point, and the sum Σ of the link refraction angles at the curve detection point and the points around it is calculated, when the sum of the link refraction angle Σ is greater than the set value Σth includes determining curve determining means and said curve detecting point is curved, pre
The curve determination means is a link at the curve detection point.
If the refraction angle is smaller than the set value θmin, the link refraction
The curve detection point is a straight line without calculating the sum Σ of angles.
The feature is that it is determined to be a road .

A second invention is the same as the first invention, wherein
The curve determination means is configured to bend the link at the curve detection point.
If the bending angle is greater than the set value θmax, the link refraction angle
Without calculating the sum Σ of
It is characterized by determining that

A third invention is a map of a navigation device.
Connect each point on the vehicle route from the point data included in the data
The refraction angle of the link is calculated, and the refraction angle of the link is used as the basis.
In a curve detection device that detects a curve,
One of the placed point data is the curve detection point, and
Link refraction at the curve detection point and its surrounding points
The sum Σ of angles is calculated, and the sum Σ of link refraction angles is set value Σ
When it is larger than th, the curve detection point is a curve
When the link refraction angle at the curve detection point is larger than the set value θmax, the curve detection point is directly curved without calculating the sum Σ of the link refraction angles. It is characterized by determining that there is.

[0013] The fourth invention is the first to third inventions, set as larger as a setting value Lth vehicle speed becomes higher, the sum L of the link length in the traveling direction from the curve detecting point is the setting with a range that does not exceed the value Lth regarded as near the curve detecting point, set value Lth of the set value Σth
It is characterized in that it is changed according to.

[0014]

According to the first invention, the link refraction angle,
Since the sum Σ of the link refraction angles can be calculated regardless of the interval of the point data, it becomes possible to perform the curve detection using the point data arranged at unequal intervals. Well
Also, the link refraction angle at the curve detection point is small and clear
If it can be regarded as a straight line, calculate the sum of the link refraction angles.
Since it is judged as a straight road without showing it, the curve detection device
The processing load on the storage is reduced. Also, the starting point of the curve
The point detection accuracy is also improved.

[0015]

According to the second and third aspects of the invention, when the link refraction angle at the curve detection point is large and can be clearly regarded as a curve, the sum of the link refraction angles is not calculated but the curve is determined as it is. The processing load in is further reduced.

According to the fourth invention, the set value Lth is changed according to the vehicle speed, and the set value Σth is changed to the set value Lth.
It is possible to perform curve detection that is more suitable for the driver's sense by changing the curve according to.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle driving force control device equipped with a curve detecting device according to the present invention.

Explaining this, the curve detecting device 1 includes a vehicle speed sensor 2 for detecting a vehicle speed, an azimuth sensor 3 for detecting a traveling direction of the host vehicle, and a satellite to GPS.
A GPS sensor 4 for detecting a signal, a navigation device 5 for detecting the current position based on information from the various sensors,
It is composed of a curve detecting means 6 for detecting a curve using the point data included in the map data of the navigation device 5.

The curve detecting device 1 (curve detecting means 6) outputs information about a curve on the route of the vehicle, and the prime mover controller 7 and the AT controller 8 follow the prime mover 9 (engine, motor, etc.) and the automatic transmission 10. To control.

Here, the processing performed in the curve detecting means 6 will be described based on the flow shown in FIG.

First, in step S21, the refraction angle θ of the link at the curve detection point is calculated from the point data included in the map data.

In steps S22 and S23, step S2
Link refraction angle θ obtained in 1 and set value θmax, set value θmin
Compare with. Set value θmax is about 15 °, set value θmin
It has been obtained from running experiments on ordinary roads that the curve can be detected according to the driver's sensation by setting 10 ° to about 10 °, but the set values θmax and θmin are limited to these values. Not the map data used, the driving conditions,
It is set to an appropriate value according to the road type and the like.

At this time, if the link refraction angle .theta. At the curve detection point is larger than the set value .theta.max, it can be said that the curve is a curve, so the process proceeds to step S24 to output the curve detection flag ON. Further, when the link refraction angle θ is smaller than the set value θmin, it can be said that the road is a straight road, so the routine proceeds to step S25 and the curve detection flag OFF is output. Also, the link refraction angle θ is the set value θma
If it is between x and the set value θmin, there is a possibility that it is a curve although it cannot be said to be a curve, so the process proceeds to step S26 to determine whether the curve is further from the sum Σ of the link refraction angles.

In step S26, the set value Lth that determines the circumference of the curve detection point is determined from the vehicle speed V at that time with reference to a map as shown in FIG.

FIG. 3 is a map showing the relationship between the vehicle speed V and the length of the road required for the driver to recognize the road shape (hereinafter referred to as road shape recognition distance). Thus, the road shape recognition distance depends on the vehicle speed V, and the higher the vehicle speed V, the larger the road shape recognition distance. Therefore, in the present invention, with reference to the map shown in FIG. 3, the set value Lth
Is set to be equal to this road shape recognition distance.

In step S27, the sum of link refraction angles Σ
Set a set value Σth, which is a threshold value for determining whether the curve is a curve.

FIG. 4 is a map showing the relationship between the curve radius and the vehicle speed passing through the curve. As shown in this figure, the vehicle speed becomes lower as the curve radius becomes smaller. Since the passing vehicle speed is greatly reduced, it can be said that the driver recognizes that the vehicle is traveling on the curve at the curve radius Rth or less. Therefore, in the present invention, the set value Σth used for the curve determination is calculated based on the set value Lth set in step S26 and the curve radius Rth. The set value Σth is calculated by the following equation. The unit of the set value Lth and the curve radius Rth is m, and the unit of the set value Σth is
rad.

Σth = Lth / Rth In step S28, a range in which the sum L of the link lengths from the curve detection point in the traveling direction does not exceed the set value Lth is regarded as the periphery of the curve detection point, and the curve detection point and its periphery exist. Calculate the sum Σ of the link refraction angles at the points.

In step S29, the sum Σ of the link refraction angles θ and the set value Lth are compared. If the sum Σ of the link refraction angles is larger than the set value Σth, it is determined to be a curve, and the process proceeds to step S30 to make a curve. The detection flag ON is output. On the contrary, when the link refraction angle Σ is smaller than the set value Σth, it is determined that the road is a straight road, the process proceeds to step S31, and the curve detection flag OFF is output.

Therefore, by processing the flow shown in FIG. 2, the curve detection means 6 outputs the curve detection flag ON when there is a curve on the vehicle path and turns off the curve detection flag when there is no curve. Is output. The prime mover controller 7 and the AT controller 8 control the prime mover 9 and the automatic transmission 10 according to the output result, and perform predetermined control such as changing the driving force characteristics to those suitable for curve traveling and performing deceleration control.

Next, the operation will be described.

FIG. 5 shows an example of the point data arranged on the route of the vehicle. When the curve detection point is point n1, the link refraction angle θ1 at point n1 (refraction angle of link L12 with respect to link L01) is If it is larger than the set value θmax, the point n1 is judged to be a curve, and if it is smaller than the set value θmin, it is judged to be a straight road.

The link refraction angle θ1 is the set value θmin and the set value θ
If it is between max, it is determined whether it is a curve by the sum Σ of link refraction angles. In this case, as shown in FIG.
Link length sum L from the curve detection point n1 toward the traveling direction
Is regarded as the vicinity of the curve detection point, the sum Σ of the refraction angles at the curve detection point n1 and points around it is determined to be a curve, and conversely, If it is not larger than the set value Σth, it is determined to be a straight road.

In FIG. 6, if the relationship between the sum of the link lengths and the set value Lth is L12 + L23 <Lth <L12 + L23 + L34, the points n2 and n3 are regarded as points around the curve detection point n1. Therefore, the sum of link refraction angles Σ is
It becomes the sum of the link refraction angles at n1, n2, and n3, and Σ = θ1 + θ2 + θ3.

The set value Lth is set from the vehicle speed at that time with reference to the map shown in FIG. 3, and the higher the vehicle speed, the larger the Lth is set. For example, at a vehicle speed of 70 km / h, it is set to about 100 m. Also, the set value Rt at this time
Since h is about 40 m from Fig. 4, the set value Σth is Σth = Lth / Rth = 100/40 = 2.5 (≈140
°).

Since the interval of the point data included in the map data of the navigation device is wide on a straight road and narrow on a curve, the interval of the point data varies greatly before and after the curve. According to the present invention, the link refraction angle and Since all of the sums Σ can be calculated regardless of the intervals of the arranged point data, it is possible to detect the curve using the point data arranged at such unequal intervals.

Further, as shown in FIG. 8, in the conventional curve detecting method, since the curvature index θ increases from before the curve start point, the point B, which is a straight road, is erroneously recognized as a curve. Then, when the link refraction angle is small, it is determined as a straight road as it is. Therefore, it is possible to prevent such a point in front of the curve from being mistakenly recognized as a curve, and to improve the detection accuracy of the start point of the curve.

Further, the sum Σ of the link refraction angles is calculated only when the link refraction angle at the curve detection point is between the set values θmin and θmax, and when the link refraction angle is large and clearly indicated by a curve, Since the sum Σ of link refraction angles is not calculated when the refraction angle is small and clearly not a curve, the processing load on the curve detection device 6 can be reduced. If the processing becomes light, it is possible to repeatedly perform curve determination for the same point, and it is possible to improve curve detection accuracy.

Further, the length of the road required for the driver to recognize the road shape becomes longer as the vehicle speed increases, and in addition to this, the range used for curve detection, that is, the set value Lth.
Is increased, it becomes possible to perform curve detection that better matches the driver's feeling.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a vehicle control device including a curve detection device according to the present embodiment.

FIG. 2 is a flowchart showing a process performed by the curve detecting means 6.

FIG. 3 is a map showing the relationship between road shape recognition distance and vehicle speed.

FIG. 4 is a map showing a relationship between a curve radius and a passing vehicle speed.

FIG. 5 is a diagram showing an example of point data arranged on a vehicle route.

FIG. 6 is another example of the point data arranged on the vehicle route (θ
The figure showing min <θ <θmax).

FIG. 7 is a diagram showing a conventional curve detection method.

FIG. 8 is a diagram showing an example of erroneous detection by a conventional curve detection method.

[Explanation of symbols]

1 Curve detector 5 navigation devices 6 Curve detection means

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-145706 (JP, A) JP-A-8-61968 (JP, A) JP-A-8-202989 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G08G 1/09-1/16 B60K 28/10 F16H 61/02 G01C 21/00

Claims (4)

(57) [Claims] 1. A curve detection device for calculating a refraction angle of a link connecting points on a vehicle route from point data included in map data of a navigation device and performing curve detection based on the refraction angle of the link, One of the point data arranged on the own vehicle route is set as a curve detection point, and a sum Σ of link refraction angles at the curve detection point and points around it is calculated, and the sum Σ of the link refraction angles is set value Σth. Is greater than, the curve determination means for determining that the curve detection point is a curve, the curve determination means, the curve determination means,
If the angle of refraction is smaller than the set value θmin,
The curve detection point is directly calculated without calculating the bending angle sum Σ.
A curve detection device characterized by determining that it is a track . 2. The curve determination means is the curve detection point.
When the link refraction angle at is larger than the set value θmax
Is the car without calculating the sum Σ of link refraction angles.
A feature that determines that the detection point is a curve.
The curve detection device according to claim 1. 3. Included in the map data of the navigation device
Angle of the link that connects each point on the vehicle route from the point data
And calculate the curve based on the refraction angle of the link.
In the curve detection device, one of the point data placed on the vehicle route is
As a starting point, place it at the curve detection point and its surrounding points
The sum of link refraction angles Σ is calculated, and the sum of the link refraction angles is calculated.
When Σ is larger than the set value Σth, the curve detection point is
When the link refraction angle at the curve detection point is larger than a set value θmax, the curve determination means includes a curve determination means for determining that the curve is the curve without calculating the sum Σ of the link refraction angles. A curve detection device characterized by determining that a detection point is a curve
Place 4. Set as larger as a setting value Lth vehicle speed becomes higher, said a range that the sum L does not exceed the set value Lth of the link length from the curve detection point to the traveling direction mosquito <br/> The curve detection device according to claim 1, wherein the set value Σth is changed in accordance with the set value Lth while being regarded as the vicinity of the curve detection point.