JPH07234999A - Monitoring device for rear of vehicle - Google Patents

Abstract

PURPOSE:To prevent a vehicle from touching an obstacle by deciding the rear road situations of the vehicle and then superimposing the recessing/projecting information screen corresponding to the road situations on a monitor screen. CONSTITUTION:A control unit 7 knows that the gear position detected by a gear position sensor 4 shows a back position of a subject. Then the unit 7 calculates the vertical component of the distance between a back-eye camera 1 and the subject set in the center of an image based on the attachment angle of the camera 1 detected by an attachment angle detector means 3 and the preceding distance measured by a distance measuring device 2. Then the calculated vertical component is compared with the attachment height of the camera 1. If the height of the camera 1 is smaller then the vertical component, the unit 7 decides that the rear road is recessing and then superimposes the corresponding recessing/projecting information screen on a monitor screen 8. Then a projecting state of the rear road is decided vice versa.

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 A vehicle rearward monitoring device, in which a rear-view camera for monitoring is attached to the rear of a vehicle and a video signal from the camera is displayed on a back-eye monitor provided in a driver's cab of the vehicle when the vehicle moves backward, is disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. As shown in Japanese Patent Publication No. 5-213113 and the like, it is well known that the image from such a back-eye camera does not have a three-dimensional effect, and there is an obstacle or a dent at the place where the vehicle is about to move backward. It is difficult to judge whether it is flat or flat from the monitor screen, especially at night etc.,
In some cases, there was the problem of leading to an accident.

Therefore, it is an object of the present invention to provide a vehicle rear monitoring device capable of monitoring the condition of a road which is about to move backward with a back-eye camera and displaying it on the back-eye monitor.

[0004]

In order to achieve the above object, a vehicle rear monitoring apparatus according to the present invention comprises a gear position detecting means, a mounting angle detecting means for the camera, and an object at the center of the image from the camera. And a road condition in which the vertical component of the distance is determined from the mounting angle and the distance when the gear position is in the reverse position and the vertical component is compared with the predetermined camera mounting height to retreat. And a control unit for superimposing an unevenness information screen corresponding to the road condition on the screen of the monitor by judging whether it is flat, concave or convex.

Further, the control unit obtains a horizontal component of the distance from the camera to the subject at the center of the image instead of the vertical component, and obtains the horizontal distance obtained by the attachment height and the attachment angle of the predetermined camera. It is also possible to compare the horizontal component and determine whether the backward road condition is flat, concave or convex.

Further, the vehicle rear monitoring device of the present invention further comprises moving distance detecting means, and the control unit is
At least one of the moving distance, the horizontal distance from the camera to the subject at the center of the image, and the difference between the vertical component and the mounting height of the predetermined camera can be displayed on the unevenness information screen.

[0007]

In the present invention, the control unit, which has been informed that the gear position detected by the gear position detecting means is the back position, has the mounting angle detected by the mounting angle detecting means of the back-eye camera and the camera. The vertical component of the distance is obtained from the distance measured by the means for measuring the distance to the object at the center of the image, and this vertical component is compared with the mounting height of the back-eye camera.

As a result of this comparison, when the mounting height of the camera is smaller than the vertical component of the measured distance, the control unit determines that the backward road condition is concave (dented state) and responds to this. Superimpose the unevenness information screen on the monitor screen.

Further, when the mounting height of the camera is larger than the vertical component, it is determined that there is a convex condition in the backward road condition and there is an obstacle, and the unevenness information screen showing this is displayed on the monitor screen. Superimpose inside.

Alternatively, when the vertical component and the mounting height of the camera are equal to each other, it is assumed that the condition of the road to retreat is flat and the unevenness information screen as described above is not superimposed.

In this way, the monitor screen on the rear side of the vehicle is made easier to understand to ensure the safety of the backward driving.

Note that the control unit does not compare the vertical component with the mounting height of the camera as described above.
Obtain the horizontal component of the distance from the camera to the subject in the center of the image, and compare the horizontal distance obtained by the mounting height and mounting angle of the camera above with the horizontal component above. You may judge whether it is a state or a convex state.

Further, if at least one of the moving distance detected by the moving distance detecting means, the horizontal distance, the vertical component, and the mounting height of the camera is displayed on the concave / convex information screen, the operation is further improved. It is a superimpose screen that is easier for people to understand.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a vehicle rear monitoring apparatus according to the present invention. 1 and a distance measuring device for measuring the distance to the subject at the center of the image, 3 an angle adjuster for adjusting the mounting angle of the back eye camera 1, 4 a gear position sensor for detecting the gear position of the vehicle 5 is a vehicle speed sensor or a mileage sensor, and 6 is an initial setting request switch.

A control unit 7 is composed of a superimposing section 71 and a data processing section 72. The superimposing section 71 is further composed of a sync separation circuit 71a and an image generating section 71b.

Further, the data processing unit 72 receives the output signals of the distance measuring device 2, the angle adjuster 3, the gear position sensor 4, the vehicle speed sensor 5 and the initial setting request switch 6, and the synchronizing signal from the synchronizing separation circuit 71a. On the basis of the above, a CPU and a memory are built in for giving a control signal to the image generating section 71b.

Further, 8 is a back-eye monitor, which has a monitor screen for appropriately displaying a vehicle rear screen from the back-eye camera 1 and a superimpose screen generated by the image generating section 71b.

The operation of the above embodiment will be described below with reference to the flow charts shown in FIGS.

First, the data processing section 72 of the control unit 7 asks whether or not to perform the initial setting shown in FIG.
(Step S1).

That is, the data processing unit 72 receives the request signal R.
When the initial setting request switch 6 is ON, the data processing unit 72 inputs the distance d from the distance measuring device 2 and the angle α from the angle adjuster 3 (step S2).

A method of measuring the distance d will be described with reference to the embodiment shown in FIG.

This distance measuring device 2 comprises two lenses 11, 1
2, prisms 13 and 14 for splitting the output light of these lenses 11 and 12, and a CCD 15 for converting the light split by these prisms 13 and 14 into an electric signal,
16, a 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 C
It is composed of 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 CDs 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 they match, the following formula (1)
The distance d shown by can be obtained.

[0025]

## EQU00001 ## d = b / tan.lamda .... Equation (1)

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

Returning to the flow chart of FIG. 2, the height h of the camera is calculated by the following equation from the distance d thus obtained and the mounting angle α (step S3).

[0028]

## EQU00002 ## h = dcos .alpha .... Equation (2)

Such distance d, angle α, and camera height h
Is shown in FIG. 5, and this height h is
If is fixed and the road surface is flat, the height is equal to the fixed height h ₀ .

Then, the height h of the camera thus obtained is stored (step S4).

Then, the previous data is cleared (step S5), and the pointer of the memory location of the memory (not shown) of the camera height h just obtained is set to the head (step S6).

Next, the superimposed display of the unevenness information screen shown in FIG. 3 is performed.

First, the data processing section 72 of the control unit 7 determines whether or not the current gear position is the back gear based on the output signal from the gear position sensor 4, and when it is in the back gear, the next step is performed. S1
Go to 2.

Then, it is judged from the output signal of the vehicle speed sensor 5 whether or not the current vehicle speed is a constant value (for example, 1 km / h) or more, and only when the vehicle speed is above such a predetermined speed, that is, the vehicle is stopped. Only proceed to the next step when there is no state.

In step S13, as shown in FIG. 6, the movement amount X _i of the vehicle 10 from the position where the back gear is engaged.
Is calculated, and ΔX in this case can be obtained by integrating the vehicle speed v. Alternatively, if a travel distance sensor is used instead of the vehicle speed sensor, the travel distance itself corresponds to this ΔX.

Next, the current horizontal distance L to the subject of the camera 1 is calculated from the distance d and the mounting angle α obtained in FIG.
_i (see FIG. 6) is obtained (step S14).

On the other hand, the height h of the camera obtained in step S3 of FIG. 2 is the mounting height h of the camera position which is known in advance if the road surface on which the vehicle 10 is traveling is flat as described above.
It should be equal to ₀ , but if there is a recessed portion in the rear of the vehicle 10 as shown in FIG. 6, the distance d should be long as shown in the figure, so that the predetermined height of the camera 1 as described above is obtained. h
The difference h _i between ₀ and the vertical component dcos α of the distance d is obtained (step S15).

Then, X _i , obtained as described above,
The memory locations of L _i and h _i are updated to the latest locations (step S16). An example of the storage state in this case is shown in Table 1 below.

[0039]

[Table 1]

Then, it is determined whether the height change h _i obtained in step S15 is positive or negative (step S17).

When it is found that the height change h _i is negative, that is, when it is found that the vertical component dcos α is larger than the predetermined height h ₀ of the camera 1, as shown in FIG. Since it can be seen that there is a recessed portion in the rear of the vehicle, the data processing unit 72 causes the image generation unit 71b to operate as shown in FIG.
A control signal is given so as to select a previously stored image in a concave state as shown in (a) (step S18).

As a result, the superimpose screen 80 as shown in FIG. 8 is partially configured and displayed on the screen of the back eye monitor 8 (step S1).
9).

On the other hand, when it is determined that the height change h _i is positive, it is conceivable that there is a convex portion behind the vehicle as an obstacle, and therefore the data processing unit 72 is used.
7 stored in advance in the image generation unit 71b.
A control signal is given to generate an image showing an obstacle as shown in (b) (step S20).

As a result, the convex portion screen is superimposed and displayed on the screen of the back eye monitor 8 (step S21).

Further, since X _i , L _i and h _i are stored in the memory as shown in Table 1 above in step S16, the horizontal distance from the vehicle to the above-mentioned uneven portion is calculated and shown in FIG. 7 and the display as shown in FIG. 8 (step S22).

It should be noted that the horizontal distance to the hollow portion or the obstacle as shown in the figure is h _i ≠ 0 for the first time in step S17.
Assuming that the moving amount when the above condition becomes X _P and the current moving amount X _i , h ₀ tan α (X _i −X _P ).

In step S17, the height change amount h
_{When i} is 0, the road surface in the rear part of the vehicle is regarded as flat and the program exits from this program. In this case, step S
Although it was judged as positive, negative, or 0 in 17, it is more than a certain positive value,
If the value is less than or equal to a negative fixed value, or none of them, the determination may be made.

Further, in step S11, it is determined whether or not the vehicle speed v is 3 km / h when the gear is not in the reverse (step S23), and when it is determined that the vehicle speed is 3 km / h or more, the above is performed. Each data shown in Table 1 is cleared (step S24), and the pointer of the storage location is set to the head (step S25).

Since the mounting angle of the camera can be arbitrarily adjusted in the above embodiment, the mounting angle is changed when the back gear is inserted, and the same mounting angle data as in Table 1 above is sampled and displayed on the monitor screen. It is also possible to display it.

[0050]

As described above, according to the vehicle rear monitoring device of the present invention, the vertical component or the horizontal component of the distance depending on the mounting angle of the camera and the distance from the camera to the object at the center of the image at the back gear position. Find the component and compare it with the mounting height of the camera or the horizontal distance obtained by the mounting height of the camera and the mounting angle to judge whether the road condition to be retreating is flat, concave or convex, and monitor screen Since the unevenness information screen corresponding to the road situation is configured to superimpose with the horizontal distance,
The following effects can be obtained.

(1) It is possible to prevent the tire from dropping into the groove and prevent contact with obstacles. (2) It is possible to supplement the stereoscopic effect that cannot be judged from the monitor screen. (3) Since the horizontal distance to the first unevenness generation portion can be displayed numerically, it is possible to make up for the lack of sense of distance, which is one of the drawbacks of cameras. (4) By making the memory backupable, for example, by displaying the unevenness information sampled during the daytime again at night, it is possible to display the unevenness information that cannot be determined from the image of the camera, which can be useful in preventing accidents.

[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 program flow chart diagram for performing an initial setting in a control unit in the vehicle rear monitoring device according to the present invention.

FIG. 3 is a flow chart diagram for performing a superimposed display of the unevenness information screen executed by the control unit in the vehicle rear monitoring device according to the present invention.

FIG. 4 is a diagram showing a configuration example of a distance measuring device used in the vehicle rear monitoring device according to the present invention.

FIG. 5 is a diagram showing an initial setting state of the vehicle rear monitoring device according to the present invention.

FIG. 6 is a diagram when detecting a concave-convex state of the vehicle rear monitoring device according to the present invention.

FIG. 7 is a diagram showing a display example of a superimpose screen stored in advance in a control unit in the vehicle rear monitoring device according to the present invention.

FIG. 8 is a diagram showing a superimpose screen displayed on the monitor by the vehicle rear monitoring device according to the present invention.

[Explanation of symbols]

 1 Back-eye camera 2 Distance measuring device 3 Angle adjuster 4 Gear position sensor 5 Vehicle speed sensor (mileage sensor) 6 Initial setting request switch 7 Control unit 71 Superimpose part 72 Data processing part 8 Back-eye monitor Indicates the same or a corresponding portion.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area H04N 7/18 J

Claims (3)

[Claims] 1. A vehicle rearward monitoring device for displaying an image from a back-eye camera provided on a rear portion of a vehicle on a back-eye monitor, wherein a gear position detecting means, a mounting angle detecting means for the camera, and an image from the camera. A means for measuring the distance to the central object, and when the gear position is the back position, a vertical component of the distance is obtained from the mounting angle and the distance, and the vertical component is compared with the predetermined camera mounting height to move backward. And a control unit for determining whether the road condition is flat, concave or convex, and superimposing an unevenness information screen corresponding to the road condition on the screen of the monitor. . 2. The control unit obtains a horizontal component of a distance from the camera to a subject at the center of the image instead of the vertical component, and a horizontal distance obtained by the attachment height and the attachment angle of the predetermined camera. The vehicle rear monitoring device according to claim 1, wherein the vehicle rearward monitoring device is configured to compare the horizontal component to determine whether the backward road condition is flat, concave, or convex. 3. A moving distance detecting means is provided, wherein the control unit has a moving distance, a horizontal distance from the camera to a subject at the center of the image, and a difference between the vertical component and a predetermined camera mounting height. The vehicle rear monitoring device according to claim 1 or 2, wherein at least one of them is displayed on the unevenness information screen.