JPH1082635A - Computing method for grade of road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a computing method for the grade of a road, in which the grade of the road can be computed by using the minimum amount of data. SOLUTION: An elevation is held, with reference to each point of a matrix, in map data in which a road track is held as a node point. Then, regarding a node point in which a grade is found, three points of an elevation near the node point are extracted (S14), and the inclinaiton vector of the face of a triangle which forms elevation data on the three points is computed (S20). After that, the grade of a road is computed on the basis of the cosine component of the inclination vector and an advance direction in the node point (S26). As a result, without providing the elevation data on every node point, the grade of the road can be found only by holding the elevation at every matrix-shaped point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calculating a road gradient based on map data used in a navigation system.

[0002]

2. Description of the Related Art A navigation device is used for displaying a detected vehicle position and a calculated route to a destination on a map display screen, that is, for presenting map information and the like to a driver or the like. I have. Further, various proposals have been made for a technique for not only presenting information or the like but also actively controlling a traveling device of a vehicle.
For example, in Japanese Patent Publication No. 6-58141, a navigation device is used to determine the road conditions at the current position of the vehicle,
A technique for changing the control pattern of the automatic transmission according to the situation has been proposed.

[0003] In the above technique, when the navigation device detects that the vehicle is traveling in a mountainous area, a control pattern for a mountainous road can be set in the automatic transmission. However, even in mountainous areas, there are downhills and winding uphills where it is desirable to select a low gear and strongly apply engine braking, as well as gently long downhills and straight uphills. . For this reason, when controlling the automatic transmission, it is desirable to detect a road gradient in addition to detecting a mountain road using a navigation device.

[0004]

Here, the method of detecting the gradient is known from the change in acceleration. However, in this method, the gradient is actually calculated and the gradient is calculated after the behavior of the vehicle is changed. Therefore, it was not possible to select a gear position according to the road gradient in advance. For this reason, a method of adding the gradient data to the road data of the navigation device and storing the data, and searching for the road gradient by the navigation device can be considered. Cannot accommodate the required map data.

The present invention has been made to solve the above-described problem, and an object of the present invention is to propose a road gradient calculating method capable of calculating a road gradient with a minimum amount of data.

[0006]

According to a first aspect of the present invention, there is provided a method for calculating a road gradient, comprising the steps of: storing an elevation for each point in a matrix; and storing a road trajectory as a node point. Extracting, for a node point for which a gradient is to be determined, three elevations near the node point; and calculating a road gradient at the node point based on a relative relationship between the three elevations and the node point. And is a technical feature.

According to a second aspect of the present invention, there is provided a method for calculating a road gradient, comprising: a step of retaining an elevation for each point in a matrix; a step of retaining a road trajectory as a node point; Extracting three points of elevation in the vicinity of the point; calculating a slope vector of a triangular surface formed by the three points of elevation data;
Calculating a road gradient from the cosine component of the inclination vector and the traveling direction at the node point.

Further, in the method for calculating a road gradient according to a third aspect, a step of retaining an elevation for each point in a matrix, a step of retaining a road trajectory as a node point, Extracting the elevation of three points near the point, calculating the elevation at the node point based on the relative relationship between the elevation of the three points and the node point, and Extracting the elevations of three points near the next node point; calculating the elevation at the next node point based on the relative relationship between the elevations of the three points and the next node point; And calculating a road gradient from the difference between the altitude of the next node point and the altitude of the next node point.

In the method for calculating a road gradient according to the first aspect, for a node point for which a gradient is to be obtained, three elevations near the node point are extracted, and a relative relationship between the three elevations and the node point is obtained. Calculates the road gradient at the node point. For this reason, it is possible to obtain the road gradient only by holding the altitude for each point in the matrix without providing the altitude data for each node point.

In the method for calculating a road gradient according to a second aspect, for a node point for which the gradient is to be obtained, three elevations near the node point are extracted, and a gradient vector of a triangular surface formed by the three elevation data is obtained. calculate. Then, the road gradient is calculated from the cosine component between the gradient vector and the traveling direction at the node point. For this reason, it is possible to obtain the road gradient only by holding the altitude for each point in the matrix without providing the altitude data for each node point.

According to a third aspect of the present invention, for a node point for which a gradient is to be obtained, three elevations near the node point are extracted, and the elevation of the three points and a relative relationship between the three points are calculated based on a relative relationship between the three elevations and the node point. Calculate the elevation at the node point. Further, with respect to the node point next to the node point for which the gradient is to be obtained, the elevations of three points near the next node point are extracted, and the elevation at the next node point is determined by the relative relationship between the elevations of the three points and the next node point. Is calculated. Then, the road gradient is calculated from the difference between the altitude of the node point and the altitude of the next node point. For this reason,
The road gradient can be obtained only by retaining the elevation for each point in the matrix without providing elevation data for each node point.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. FIG. 1 shows a control mechanism of an automatic transmission according to a first embodiment of the present invention.
This vehicle includes a vehicle navigation device 10 that detects the position of the vehicle and provides route guidance, and an automatic transmission 60 that sets an optimal control pattern.
Control unit 20 for controlling the
And an engine control unit 30 for controlling the engine 50.

The navigation device 10 receives radio waves from artificial satellites via an antenna 12 using a GPS (Global Positioning System), calculates a current position, reads out map data recorded in a CDROM 14, reads out map data from a Identify your current location in. Moreover,
As will be described later, data relating to the road environment such as a mountain area in the map data, the current position, and the calculated degree of road inclination are sent to the automatic control unit 20.

[0014] Engine control unit 30, based on a signal of the throttle opening from the throttle 70, the number engine rotation from the engine 50 other (coolant temperature, 0 ₂ sensor signals, etc.), fuel injection command to the engine 50 To control the engine 50.

Automatic control unit 20
Is configured to give a gear shift command to the automatic transmission 60 according to a selected control pattern based on a throttle opening signal from the throttle 70 and a vehicle speed from the automatic transmission 60. Further, the automatic transmission 60 switches the shift speed in accordance with the operation of the shift lever 74. Further, the automatic transmission 60 is configured to select an appropriate shift speed in accordance with a road environment and a road gradient described later in a state where the drive range is selected.

Here, prior to the description of the method of calculating the road gradient by the automatic control unit 20 of the present embodiment, the contents of the map data recorded in the CDROM 14 will be described with reference to FIG. FIG. 2 schematically shows the contents of the map data. In the figure, a solid line R indicates a road. Here, in the map data, the road is digitized as a locus defined by a plurality of node points N1, N2,. That is, the coordinates (latitude / longitude) of each node point shown in the figure are held as data, and the road is processed as a series of line segments (hereinafter referred to as links) connecting the node points. . The method of converting a road into data using the node points is generally adopted as navigation data.
Here, the link connecting the relatively widely spaced node points N1 and N2 is a substantially straight road, and the narrowly spaced node points N3, N4... N9 are S-shaped curved roads. .

On the other hand, in the first embodiment, altitudes are held in a matrix in addition to the above-described node points for conceptualizing roads. Each point in this matrix is
They are provided at intervals of 250 m. For example, in the figure, 10-
The elevation point designated by 10 is 20 m above sea level, and 10-1
The elevation point designated by 1 is 22 m above sea level.

In the first embodiment, the inclination of the road is obtained by the above-mentioned matrix-like elevation data based on the data of the node points indicating the inflection points of the conventional road. This processing will be described with reference to the flowchart of FIG. 5 and the explanatory diagrams of FIGS. First, the navigation device 10
Searches for the position of a node point scheduled to pass in front of the traveling road (S12). Here, the node point N shown in FIG.
It is assumed that 1 has been searched. Next, three elevation points near the searched node point are extracted (S14). Here, an elevation point 10-10, an elevation point 10-11, and an elevation point 11-10 are extracted. Then, the coordinates (latitude / longitude) and elevation data of the three elevation points are read (S16).

FIG. 3 is an enlarged view of the three elevation points.
Next, a triangular surface D1 is formed from the three elevation data as shown in the figure (S18). In the figure, the altitude point 11-10 is the highest at an altitude of 24 m, the altitude point 10-11 is the next highest at an altitude of 22 m, and the altitude point 10-10 is shown horizontally.
Since 10 is the lowest at an altitude of 20 m, the triangular surface D1 is
It should be noted that it is formed to be inclined toward the elevation point 10-10.

Thereafter, a vector indicating the inclination of the surface of the triangle is calculated (S20). The inclination vector V1 of the triangle formed by these three points is shown in FIG. 4. Here, the inclination vector V1 heading to the upper right in the figure is obtained from the lowest elevation point 10-10. Elevation point 11-10 is elevation point 1
Since it is higher than 0-11, the slope vector is
It is heading closer to the -10 side. For example, when the elevation point 11-10 and the elevation point 10-11 have the same elevation, the inclination vector becomes the elevation point 11-10 and the elevation point 10-10.
-11, and point 10-1.
When 1 is higher than the elevation point 11-10, the inclination vector moves toward the elevation point 10-11. On the other hand, when the elevations of the elevation points 11-10 and 10-11 are higher, the total length of the inclination vector becomes longer.

Next, an angle θ1 between the inclination vector V1 and the traveling direction of the road (here, the direction from the node point N1 to the node point N2) F1 is calculated (S22). Next, based on whether the angle θ1 exceeds 90 ° or less than 90 °, it is determined whether the angle is an ascending slope or a descending slope. Here, when θ1 is 90 °, it is determined that the road is a flat road. On the other hand, when the angle θ1 exceeds 90 °, it is determined that the road is a down road, and the angle θ1 is determined as shown in the drawing.
Is less than 90 °, it is determined that the road is an uphill road.

Here, for example, the vehicle moves in the opposite direction, that is, from the node point N2 to the node point N1, and the node point N1
Will be described from FIG. Here, the traveling direction F2 is determined to be a downward gradient because the angle θ2 between the traveling direction F2 and the inclination vector V1 exceeds 90 ° as shown in the figure.

Finally, the navigation device 10 calculates the degree of the road gradient from the magnitude of the cosin component between the inclination vector V1 and the traveling direction F1 of the road (S2).
6), and send it out to the automatic control unit 20 side. By the end of the processing for the node point N1, the next node point N1 is continuously displayed as shown in FIG.
A similar process is performed for No. 2 to determine whether it is an uphill slope or a downhill slope, and the degree of the road slope is calculated.

The automatic control unit 20 to which the up / down gradients and the road gradients are input from the navigation device 10 determines whether the interval between the node points shown in FIG. 1 is a straight road or a curved road. At the same time, the shift speed is controlled based on the degree of inclination from the navigation device 10. For example, when the downhill gradient is large on a curved road, a low shift speed is selected to apply the engine brake strongly, and when the gradient is small on a straight road, a high shift speed is selected to suppress fuel consumption.

Next, a method of calculating a road gradient according to a second embodiment of the present invention will be described with reference to the explanatory diagram of FIG. 6 and the flowchart of FIG. The mechanical configuration of the device of the second embodiment is the same as that of the first embodiment described above with reference to FIG. 1, and the configuration of the map data is described above with reference to FIGS. Since this is the same as the first embodiment, reference is made to FIGS. 1, 2 and 3 and the description thereof is omitted.

In the first embodiment described above, the degree of the road inclination is calculated for each node point. In the second embodiment, the elevation of the two node points is obtained, and the road difference is calculated from the elevation difference between the two node points. Find the slope. Prior to this description, a method of calculating the elevation of each node point will be described with reference to FIG.
Here, it is assumed that the altitude of the node point Nn surrounded by the altitude points A, B, and C is calculated.

The coordinates of the elevation point A are (Xa, Ya, Za),
The coordinates of the elevation point B are (Xb, Yb, Zb), the coordinates of the elevation point C are (Xc, Yc, Zc), the X coordinate of the node point Nn is x, the Y coordinate is y, and the Z coordinate, that is, , And the desired altitude is Z. Here, the plane ABC is defined by the following equation (1).

## EQU1 ## Lx + My + Nz = 1 Equation 2 is established from the formula of Kramer.

(Equation 2) Here, Equation 3 is established.

(Equation 3) From the above equations (1) to (3), Z can be obtained by the following equation (4).

(Equation 4)

Next, a method of calculating a road gradient according to the second embodiment will be described with reference to the flowchart of FIG. First, the navigation device 10
The position of a node point to be passed ahead of the traveling road is searched (S32). Here, it is assumed that the node point N1 shown in FIG. 2 has been searched. Next, 3 near the searched node point
The elevation point is extracted (S34). Here, altitude point 1
0-10, elevation points 10-11, and elevation points 11-10 are extracted (see FIG. 3). Then, the coordinates (latitude / longitude) of the three elevation points and the elevation data relating to the elevation are read (S
36). Then, from the three elevation data, the elevation of the node point (here, the node point N1) is calculated as described above with reference to FIG. 6 (S38).

Thereafter, the position of the node point to be passed next is searched (S40). Here, the node point N shown in FIG.
It is assumed that 2 has been searched. Next, three elevation points near the searched node point are extracted (S42). Here, an elevation point 10-12, an elevation point 11-11, and an elevation point 11-12 are extracted (see FIG. 3). Then, the elevation data of the three points is read (S44). Then, the altitude of the node point (here, the node point N2) is calculated from the altitude data of the three points (S46). Thereafter, the altitude of the node point N1 calculated in step 38 and the value of N2 calculated in step 46 are calculated.
The road gradient is calculated from the difference from the altitude and the distance between the two node points (S48).

The method for calculating a road gradient according to the first embodiment described above has the advantage that the gradient can be continuously determined even if the surface formed by the elevation data changes. On the other hand, the method of the second embodiment has the advantage that the road gradient can be calculated accurately.

[0031]

As described above, according to the road gradient calculating method of the present invention, the road gradient is obtained only by holding the elevation for each matrix point without providing the elevation data for each node point. Therefore, there is a remarkable effect that the road gradient can be calculated with a minimum amount of data. Further, in addition to the map data for the navigation device that defines the road trajectory by the existing node points, the present embodiment can be configured only by having the elevation data in the matrix coordinates, so that the map data can be easily created. There are certain advantages.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device for an automatic transmission using a road gradient calculation method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the contents of map data according to the first embodiment.

FIG. 3 is an explanatory diagram showing a part of the explanatory diagram of FIG. 2 in an enlarged manner.

FIG. 4 is an explanatory diagram showing a tilt vector calculation according to the first embodiment.

FIG. 5 is a flowchart illustrating processing of a road gradient calculating method according to the first embodiment.

FIG. 6 is an explanatory diagram showing altitude calculation according to a second embodiment.

FIG. 7 is a flowchart illustrating a process of a road gradient calculating method according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Navigation apparatus 20 Automatic control unit 60 Automatic transmission N1, N2 Node point 10-10, 10-11 Elevation point V1, V2 Slope vector

Claims (3)

[Claims] 1. A step of retaining an elevation for each point in a matrix, a step of retaining a road trajectory as a node point, and a step of extracting three elevations near a node point for which a gradient is to be determined. Calculating a road gradient at the node point based on the relative heights of the three points and the node point. 2. A step of retaining an elevation for each point in a matrix, a step of retaining a road trajectory as a node point, and a step of extracting three elevations near a node point for which a gradient is to be obtained. Calculating a gradient vector of a triangular surface formed by the three points of elevation data; and calculating a road gradient from a cosine component between the gradient vector and the traveling direction at the node point. Road slope calculation method. 3. A step of retaining an elevation for each point in a matrix, a step of retaining a road trajectory as a node point, and a step of extracting three elevations near a node point for which a gradient is to be obtained. Calculating the elevation at the node point based on the relative relationship between the elevations of the three points and the node point; and for the next node point of the node point for which the gradient is to be determined, the elevations of the three points near the next node point Extracting the height of the three nodes and calculating the altitude at the next node point based on the relative relationship with the next node point; and calculating the road from the difference between the altitude of the node point and the altitude of the next node point. Calculating a gradient.