JP3473991B2 - Camera failure diagnosis device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera failure diagnosing device, and more particularly to a CCD camera failure diagnosing device used in a device for detecting deviation from a lane of a vehicle.

[0002]

2. Description of the Related Art JP-A-59-128693 or JP-A-3-27
In the lane departure warning device conventionally known from the 3498 gazette and the like, the front of the vehicle is photographed by a CCD camera as lane detection means, and the controller extracts the lane on the road surface from the obtained image data signal, When the distance between the lane and the vehicle is in a dangerous state of a certain value or less, if the direction indicating operation is not performed, the alarm device is energized to issue an alarm.

A CCD camera used in such a lane departure warning device is composed of, for example, a one-dimensional CCD sensor and a signal processing section, and a signal captured by the CCD sensor is converted into a digital signal in the signal processing section by an external controller. Normally, an 8-bit parallel signal is transmitted.

[0004]

When one or more of the signal lines for sending data from the CCD camera that outputs a digital signal to the controller in this way are broken or short-circuited (including contact failure). Since there is no means for judging abnormalities in the past, even if the wire is broken, the brightness intensity is only shifted downward in parallel from the normal time shown by the solid line in FIG. 4 to the abnormal time (when the wire is broken) shown by the dotted line. However, there is a problem in that it is impossible to distinguish whether or not the object viewed by the camera has changed, and the controller makes a misjudgment and an output abnormality to the controlled object occurs.

Further, as a conventional example for detecting the disconnection of the signal line, there are JP-A-63-308580 and JP-A-4-326072, and these also require an extra signal line. , It is not possible to detect the disconnection of one or more signal lines.

Furthermore, if such a parity signal parity check is performed, an increase in wiring and an increase in circuits will occur.

Therefore, according to the present invention, in a failure diagnosing device for a camera which outputs a parallel signal of a predetermined number of bits, even if at least one of the parallel signals is disconnected or short-circuited without increasing the circuit configuration, the problem can be solved. The purpose is to enable fault diagnosis.

[0008]

In order to achieve the above object, in a camera failure diagnosis apparatus according to the present invention, a logical value represented by a parallel signal having a predetermined number of bits is set to be equal to or less than a dark output value. The feature is that a failure is determined when the determination value is lower than a certain time.

A CCD camera can be used as the above camera.

[0010]

For example, a CCD camera has a certain output voltage in the dark, not 0V, due to its general electro-optical characteristics.

Therefore, in the present invention, if the dark output value (dark level) or a value lower than the dark output value is set as the determination value, the output value of the CCD camera can be determined by the determination value in any case under normal conditions. Paying attention to the fact that the value does not fall below the value, a failure is judged when the logical value represented by the parallel signal is below the judgment value and this continues for a certain time or longer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a camera failure diagnosing device according to the present invention. In the figure, 1 indicates a CCD camera, and this CCD camera 1 includes a lens 2, a CCD sensor 3 and a signal processing section. It is composed of 4 and.

The CCD camera 1 has a parallel signal line 5
Is connected to the controller 6 via. The controller 6 includes an input port 61 for receiving various input signals and a buffer 62 connected to the parallel signal line 5.
, ROM 63, RAM 64, output port 65 for outputting monitor output and alarm signal, these input port 61, buffer 62, ROM 63, RAM 6
4, a CPU 67 connected to the output port 65 via a common bus 66.

The output port 6 of the controller 6
Reference numeral 5 is connected to an external alarm device 7, and is further provided with a constant voltage power supply 68 for receiving a DC voltage from the vehicle battery 8 and supplying a constant voltage to each component of the controller 6.

FIG. 2 shows the ROM 63 in the controller 6.
A flowchart of a program which is stored in and is executed by the interaction of the CPU 67 and the RAM 64 is shown. The operation of the embodiment of the present invention will be described below with reference to this flowchart.

First, the signal picked up by the CCD camera 1 is converted into an electric signal by the one-dimensional CCD sensor 3 of 512 pixels (2 ⁹ = 1FF _(HEX) ) and the parallel signal line 5 is converted into digital data by the signal processing unit 4. Controller 6
Of the buffer 62.

As a result, in the CPU 67, the buffer 62
The input data is taken in further (step S1) and the brightness data processing of this input data is performed (step 2). The brightness data processing includes the lane departure warning processing as described above.

Then, it is determined whether or not the data after the brightness data processing is below the failure determination value (step S3).

The failure judgment value will be described below. If the parallel signal line 5 is a signal line composed of 8 bits, the logical value of the parallel signal line 5 is as shown in Table 1 below. It will be

[0020]

[Table 1]

Now, when the signal line on the lower bit (LSB) side is broken, the amount of data shift is small and the influence on control is small. Therefore, the failure determination value may be determined in consideration of the degree of influence on control.

As described above, since the output voltage in the dark is not 0V but has a certain value due to the general electro-optical characteristics of the CCD sensor 3, the luminance intensity is FF _{(HEX) at} maximum. On the other hand, this dark output value is 30 ± 5 _(HEX)
Then, under normal conditions, it does not fall below this value in any case.

Therefore, for example, as shown in Table 1 above, the fourth bit from the upper (MSB) is used as a failure judgment value, and when the judgment value, that is, 10 _(HEX), exceeds the data from the parallel signal line 5, it is normal. And returns to the original program (step S4), but the above-mentioned failure judgment value 10
_When it is determined that it is _(HEX) or less, the condition is that this continues for a predetermined time (step S5), it is determined to be abnormal (disconnection, etc.), and the CPU 67 activates the alarm device 7 via the output port 65 to issue an alarm. Emit.

The normal data and the abnormal data at this time are shown in FIG. 3, and the data (dotted line) lower than the judgment value 10 _(HEX) lower than the level 30 _(HEX) at the dark time is a failure. It is possible to determine that there is, and it is possible to determine that the luminance intensity exceeding the determination value 10 _(HEX) is the data at the normal time.

Although the above judgment value 10 _(HEX) is set to 20 _(HEX) lower than the dark level 30 _(HEX) , it is necessary to experimentally determine the number of lines with a high possibility of disconnection of the signal line. Therefore, various values can be set if the dark level is 30 _(HEX) or less.

[0026]

As described above, according to the camera failure diagnosing device of the present invention, the judgment value in which the logical value represented by the parallel signal of the predetermined number of bits is set to the dark output value or less for a predetermined time Since it is configured to determine a failure when it is below, it can be reliably determined to be abnormal even if at least one of the parallel signal lines is disconnected or short-circuited, and this is performed without increasing wiring or increasing the number of circuits. It becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a camera failure diagnosis apparatus according to the present invention.

FIG. 2 is a flow chart diagram of a program stored and executed in the camera failure diagnosis apparatus according to the present invention.

FIG. 3 is a graph diagram for explaining the operation of the camera failure diagnosis device according to the present invention.

FIG. 4 is a graph diagram for explaining an operation of a conventional example.

[Explanation of symbols]

1 CCD camera 3 CCD sensor 4 Signal processing unit 5 parallel signal lines 6 controller 67 CPU 7 alarm In the drawings, the same reference numerals indicate the same or corresponding parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Gyza 5-20-10 Kamata, Ota-ku, Tokyo 2nd Misu Building 4F, Isuzu AIKC Co., Ltd. (72) Inventor Toshi Sugimura Miya 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Transtron Co., Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 17/00 H04N 5/225 H04N 5/30

Claims (2)

(57) [Claims] 1. A failure diagnosing device for a camera that outputs a parallel signal of a predetermined number of bits, when a logical value represented by the parallel signal is lower than a determination value set to a dark output value or less for a predetermined time or more. A camera failure diagnosis device characterized by determining a failure. 2. The camera failure diagnosis device according to claim 1, wherein the camera is a CCD camera.