JPH07239999A - Device for monitoring behind vehicle - Google Patents

Abstract

PURPOSE:To display a marking point as a standard of distance on the screen of a back-eye monitor only when a vehicle moves back by superimposing the marking point on the screen of the back-eye monitor when the gear is at the reverse position. CONSTITUTION:The image generation part 63b of a superimposition part 63 reads the coordinates of a mark MK corresponding to a point P of 1m on a line from the point right below a back-eye camera along the left width side of the vehicle from the screen of the back-eye monitor 7, and the coordinates are supplied, from a keyboard 4 to a data processing part 62 and stored. Similarly, the coordinates of a point Q of 2m on the left side are read from the monitor screen, and the coordinates are inputted from the keyboard 4 and stored. When it is decided that the reverse gear is currently engaged from the output signal of a gear position sensor 5, the data processing part 62 controls an image switching part 61 to control the image generation part 63b so that the marking point is superimposed on the monitor screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle rear monitoring device, and more particularly to a vehicle rear monitoring device for displaying an image from a back eye camera provided at the rear of a vehicle on a back eye monitor.

[0002]

2. Description of the Related Art Conventionally, in order to monitor the road condition of a vehicle when it is moving backward, a device for monitoring a back-eye camera 1 is provided at the rear of the vehicle 10 as shown in FIG.

In such a vehicle rearward monitoring device, in order to give the driver an indication of the rearward distance when the vehicle 10 moves backward, marks MK are provided on the road surface at intervals of 1 m, for example, as shown in the figure. When the vehicle is monitored by the back eye monitor 7 provided in the driver's seat, a marking sticker MS is attached to the mark MK on the screen of the back eye monitor 7 as shown in FIG. We are trying to improve.

[0004]

However, in this way, the marking sticker MS is displayed on the screen of the back eye monitor 7 in this way.
If the back eye monitor 7 is used for a multiple image display device, the marking seal MS will be displayed as an image when other television screens or video screens are viewed as multiple images. There was a problem that it hindered the

Therefore, the present invention provides a vehicle rear monitoring device for displaying multiple images, which displays an image from a back eye camera provided at the rear of the vehicle on the back eye monitor, and displays on the screen of the back eye monitor only when the vehicle moves backward. The purpose is to display the marking points that are a measure of the distance.

[0006]

In order to achieve the above object, in the vehicle rear monitoring apparatus according to the present invention, two points are set based on the data input means, the gear position detecting means, and the reference object on the road surface. When plane coordinate data is input from the input means, the plane coordinates of other points are geometrically calculated using the mounting angle of the camera, the vertical angle of view, and the mounting height, and stored as marking points. A control unit that superimposes the marking point on the screen of the back eye monitor when the gear position is the back position.

The control unit can calculate the mounting angle of the camera based on the plane coordinate data of the two points.

Further, in the above-mentioned vehicle rear monitoring device, means for measuring the distance between the camera and the subject at the center of the image is provided, and the control unit controls the mounting height based on the distance and the mounting angle. Can be calculated.

[0009]

In the present invention, the marking point is obtained and stored, and the marking point stored only when the gear position detected by the gear position detecting means is the back position is displayed on the screen of the back eye monitor. It is designed to be superimposed.

In this case, the method of obtaining the marking points is as follows. First, a reference object (see FIG. 8) is installed on the road surface, and two points obtained on the monitor screen as shown in FIG. 9 are based on the reference object. The plane coordinate data is input from the data input means, and when this data is input, the control unit geometrically uses the mounting angle of the back eye camera, the vertical angle of view, and the mounting height to determine points other than the above two points. For calculating the plane coordinates of.

If the camera mounting angle is not a fixed value, the control unit can also calculate the mounting angle based on the plane coordinate data of the two points.

Further, when the mounting height of the camera is not known, a means for measuring the distance between the camera and the subject at the center of the image is provided, and the control unit mounts it based on the measured distance and the above mounting angle. It is also possible to calculate the height and obtain the marking point.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a vehicle rear monitoring apparatus according to the present invention. In the figure, 1 is a back-eye camera, in which a distance measuring device 20 (described later) is incorporated. There is. The distance measuring device 10 is a control unit 6
It may be provided in.

Reference numeral 2 is a television tuner when the vehicle rear monitoring device is used together with the back eye camera 1 for displaying multiple images, and 3 is also a video deck.

Reference numeral 4 is a keyboard as data input means, and 5 is a gear position sensor as gear position detecting means.

The control unit 6 is an image switching section 61 for switching and inputting image signals from the back-eye camera 1, the TV tuner 2 and the video deck 3.
And a CPU for switching and controlling the image switching unit 61 by receiving the distance data d from the distance measuring device 20 provided in the back-eye camera 1, the input data from the keyboard 4 and the gear position signal from the gear position sensor 5, and A predetermined image is received by receiving a control signal from the data processing unit 62 having a built-in memory and the image signal from the image switching unit 61, which separates the synchronization signal from the image processing unit 62 and provides the data to the data processing unit 62. And a superimposing section 63 having an image generating section 63b for generating the. Also,
7 is a back eye monitor, and the control unit 6
The image from the superimposing section 63 is displayed on the monitor.

FIG. 2 is a flowchart showing the marking point setting processing executed by the data processing unit 62 in the embodiment shown in FIG. 1, and this flowchart will be described below.

First, when an instruction key for setting a marking point to the data processing unit 62 is operated on the keyboard 4, the data processing unit 62 switches the image switching unit 61 to the position as shown in the figure and the image from the back-eye camera 1 is switched. The signal is sent to the superimposing section 63.

At the same time, the data processing unit 62 causes the image generation unit 63b of the superimposing unit 63 to display a superimpose display on the screen of the back eye monitor 7 as "Please input a point of 1m on the left side." The image generation unit 63b is controlled as if it were done (step S1). The superimpose display image is stored in the image generating unit 63 in advance.

Here, in the current state of the back-eye camera 1, it is necessary to set the marks MK at the rear of the vehicle 10 at equal distances, as in the case shown in FIG. The mark MK is displayed on the screen of the back eye monitor 7 as shown in FIG.

Conventionally, a marking sticker MS is pasted on such a screen, but in the case of the present invention, the back eye camera 1 is displayed from such a screen of the back eye monitor 7 as shown in FIGS. 3 and 4. A mark MK corresponding to a point P of 1 m on a line along the left side of the width of the vehicle 10 from a point directly below
Is read from the screen and the coordinates (x ₁ , y ₁ ) are given to the data processing unit 62 from the keyboard 4 and stored (step S2). The coordinates (x ₁ , y ₁ ) can be automatically calculated by the data processing unit 62 by the conventional technique.

Thereafter, similarly, a superimpose display is performed even at the point 2m on the left side (step S
3) And the coordinates (x ₂ , y ₂ ) are read from the monitor screen and input by the keyboard 4 and stored (step S4).

The two marking points P and Q input and stored in this manner are indicated by the circles in FIG. 4, and based on the two marking points previously input in this manner, the marks X are also shown in FIG. The coordinates of the points R, S, ... Shown by marks are obtained and stored as described later (step S
5).

The data processing unit 62 controls the image switching unit 61 to the position shown in the figure and controls the points R, S and The image generation unit 63b is controlled so as to superimpose on the monitor screen with ... as a marking point.

Next, how to obtain the coordinates of points R and S among the points marked with X shown in FIG. 4 referred to in step S5 of FIG. 2 will be described below with reference to FIGS.

First, as shown in FIG. 5, the back-eye camera 1 is used.
Is α, and the vertical angle of view of the camera 1 is equally θ on both sides of a line connecting the image center of the camera 1 and the subject C.

Note that the height of the camera 1 is h, and the camera 1
Letting d be the distance from the object to the subject C at the center of the image, if any two of these parameters h, α, d are known in advance, the other can be determined.

When it is known that the mounting height h of the camera 1 is constant, the distance d is automatically changed to d = h /
It will be obtained from cos α.

When the mounting height h of the camera 1 is not constant, the distance d is calculated to take the angle α into consideration and the height h is considered.
Can be asked.

Further, the mounting angle α of the camera 1 can be obtained from the inclination of the coordinates (x ₁ , y ₁ ) and (x ₂ , y ₂ ) of the two points for which data has been input, as in the following equation.

[0031]

[Formula 1] α = tan ⁻¹ (x ₂ −x ₁ ) / (y ₂ −y ₁ ) ... Formula (1)

The above-mentioned distance d can be measured by the measuring device 20, and one structural example of this measuring device 20 is shown in FIG.

This distance measuring device 20 comprises two lenses 11,
12, prisms 13 and 14 for splitting the output light of these lenses 11 and 12, and these prisms 13 and 14
CCD1 for converting the light dispersed by the light into an electric signal
5, 16 and CCD 17 for converting the output light of one prism 13 into an electric signal and sending it to the back eye monitor 8.
And an image comparator 18 which outputs the distance d between the camera and the subject at the center of the image by the output signals of the CCDs 15 and 16.

First, assuming that the CCDs 15 and 16 receive the image of the central portion of the image received by the CCD 17,
The output signals from the CCDs 15 and 16 are sent to the image comparator 18 to determine whether the images match.

When these images do not match, the image comparator 18 sets the rotating prism 14 at λ /
If the images are rotated by 2 and the images match each other, the distance d expressed by the following equation can be obtained.

[0036]

## EQU00002 ## d = b / tan.lamda .... Equation (2)

The image comparison in the image comparator 18 may be performed simply by comparing the illuminance, or a pattern recognition technique may be used.

FIG. 7 is a diagram for obtaining the respective coordinates of the X marks P and Q shown in FIG. 4. Hereinafter, referring to FIG.
How to obtain the coordinates of Q will be described step by step.

(1) First, assume that the position of the back-eye camera 1 is point B, the point directly below it is point A, and the length between points B-A is fixed when the camera 1 is fixed in height. It corresponds to the height h.

(2) As shown in FIG. 5, angle α from point B
Let C be the intersection of the straight line drawn with and the x-axis, and use this coordinate as the angle of view center for the mounting angle α and the distance between AB, that is, the camera 1.
The coordinates are calculated based on the mounting height h of.

(3) When the coordinates of the point C of the angle of view are obtained in this manner, a straight line having an angle θ which is half the vertical angle of view 2θ in the negative direction with respect to the straight line BC, as shown in FIG. If the intersection with the x-axis is drawn as the D point and the straight line with the same angle θ is drawn in the positive direction and the intersection with the x-axis is taken as the N point, the D point corresponds to the lower end of the angle of view and the N point is the image. It corresponds to the top of the corner.

(4) In this case, the x coordinate of point D is htan
Since it is determined by (θ-α), if a straight line with an angle α is drawn from this D point, it will intersect the straight line BC at a right angle at the E point. Since the coordinates of the points B, C, and D can be calculated as described above, the function of the straight line BC and the function of the straight line DE are obtained respectively, and the coordinates of the intersection E of both function lines are also obtained by the calculation. Becomes

(5) The lengths of the points E and D correspond to the coordinates Y at the center coordinates (X, Y) since the screen center corresponds to the point E in FIG. , Y at the coordinates (x ₁ , y ₁ ) input in step S2 of FIG.
_The point corresponding to ₁ is the F point. Therefore, since the length of the straight line DF is y ₁ , the coordinates of the point F can be obtained from the angle α.

(6) Therefore, the straight line B connecting the points B and F
Since the function of F can be determined, the coordinates of the intersection point P between this straight line BF and the x axis can also be obtained. The point P corresponds to the coordinates at a point 1 m away from the point A directly below the camera 1 input in step S2 of FIG. 2 (see FIGS. 4 and 5).

(7) Since the point P having a distance of 1 m from the position directly below the camera is obtained in this manner, when the Q point, the R point and the S point are obtained at the same intervals as the line segment AP, 2 m from the point A, respectively.
The length is equivalent to points 3 m and 4 m apart (see FIG. 4).

(8) Q point, R obtained in this way
Since the functions of the straight lines BQ, BR and BS between the points S, B and B are obtained respectively, the intersections of these straight lines and the extension of the straight line DE are I, K and M points as shown in the figure. Then, the coordinates are obtained as the intersection of the respective functions.

(9) In addition to this, considering the mounting angle α, F
Obtained be added in the x-coordinate of the point and the y coordinate y ₃ and y-coordinate y ₄ of 4m apart × mark points on the screen of the × mark points away 3m from the vehicle rear portion as shown in FIG. 4, respectively It will be.

(10) And, these left 3m, 4
The x-axis coordinates x ₃ and x ₄ of the point m can be obtained as the coordinates of the point on the straight line connecting the coordinates (x ₁ , y ₁ ) and (x ₂ , y ₂ ) of the two points previously input. .

(11) And further 1m, 2m, 3 on the right side
The points m and 4m are determined as the left and right symmetrical coordinates of the point on the left side of the line connecting the center lines (X, 0) and (X, 2Y) in the vertical direction on the screen shown in FIG. You can do it.

Incidentally, in the coordinate calculation process (1) to (11) of each of the above marking points, a detailed function calculation is omitted mainly because of the geometrical description, but such calculation processing is performed by the current computer processing. Is well known in.

[0051]

As described above, according to the vehicle rear monitoring device of the present invention, the plane coordinate data of two points are input based on the reference object on the road surface, and the mounting angle of the camera at this time and the vertical direction. Using the angle of view and the mounting height or the distance from the camera to the object, geometrically calculate the plane coordinates of the other points and store them as marking points. Since it was configured to superimpose on the monitor screen,
Even in a vehicle rear monitoring device that may display a television or video image, the marking point can be displayed only when the vehicle moves backward, and the function of image multiple display can be maintained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle rear monitoring device according to the present invention.

FIG. 2 is a flowchart showing a marking point setting process executed by a control unit of the vehicle rear monitoring device according to the present invention.

FIG. 3 is a diagram for explaining the operation principle of the vehicle rear monitoring device according to the present invention.

FIG. 4 is a diagram showing a screen of a back eye monitor during marking point setting processing of the vehicle rear monitoring apparatus according to the present invention.

FIG. 5 is a diagram showing parameters that are prerequisites for obtaining the coordinates of marking points in the vehicle rear monitoring device according to the present invention.

FIG. 6 is a diagram showing an example of the configuration of means for measuring the distance between the camera and the subject at the center of the image, which is used in the vehicle rear monitoring apparatus according to the present invention.

FIG. 7 is a geometrical explanatory diagram for obtaining the coordinates of each marking point in the vehicle rear monitoring device according to the present invention.

FIG. 8 is a diagram for explaining a method of initial setting of the back eye monitor in the related art and the present invention.

FIG. 9 is a diagram when a marking sticker is attached to a conventional back eye monitor.

[Explanation of symbols]

 1 Back-eye camera 4 Keyboard 5 Gear position sensor 7 Back-eye monitor 6 Control unit 61 Image switching unit 62 Data processing unit 63 Superimpose unit 20 Distance measuring device In the drawings, the same reference numerals indicate the same or corresponding parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 7/18 J

Claims (3)

[Claims] 1. A vehicle-rear monitoring device for displaying an image from a back-eye camera provided on a rear portion of a vehicle on a back-eye monitor, comprising: a data input means, a gear position detecting means, and a reference object on a road surface. When the plane coordinate data of a point is input from the input means, the plane coordinates of other points are geometrically calculated using the attachment angle of the camera, the vertical angle of view, and the attachment height, and stored as a marking point. A vehicle rear monitoring device comprising: a control unit that superimposes the marking point on the screen of the back eye monitor when the gear position is the back position. 2. The vehicle rear monitoring device according to claim 1, wherein the control unit calculates the mounting angle of the camera based on the plane coordinate data of the two points. 3. A means for measuring the distance between the camera and a subject at the center of the image, wherein the control unit calculates the mounting height based on the distance and the mounting angle. Item 3. The vehicle rear monitoring device according to Item 1 or 2.