JPH08164808A - Obstruction detecting device for vehicle - Google Patents

Abstract

PURPOSE: To change a detecting range in an instant by providing a scanning change control means for changing the scan range of plural infrared detecting elements scanned by a scanning means according to the vehicle speed detected by a vehicle speed detecting means. CONSTITUTION: In the case of low speed travel being judged by a vehicle speed judging part 107, a scanning change control part 108 sets a scan range, scanned by a scanning part 103, to the horizontal element number M=0-511 and vertical element number N=0-511 of infrared detecting elements 201 (all the elements of plural infrared detecting elements 201). In the case of high speed travel being judged by the vehicle speed judging part 107, the scanning change control part 108 sets the scan range, scanned by the scanning part 103, to N=0-511 which is the whole area to the vertical element number N of the infrared detecting elements 201 and to the elements up to the 256th row, up to M=128--383 to the horizontal element number M, that is, the half of the scan range at the low speed travel time. The scan range of an infrared detecting part 102 scanned by the scanning part 103 is thereby changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle obstacle detecting device for detecting the presence of a human being or the like by an infrared ray detecting element, and more particularly to a vehicle obstacle detecting device for changing the obstacle detecting area in accordance with the vehicle speed. Regarding

[0002]

2. Description of the Related Art As a conventional vehicle obstacle detection device, for example, there is a device disclosed in Japanese Patent Application Laid-Open No. 62-195579. This device adjusts the distance between the laser beam transmitting lens and the laser diode based on the information from the vehicle speed sensor, and changes the divergence angle of the laser beam to change the detection area.

That is, when the vehicle is traveling at a low speed, the divergence angle of the laser beam is increased so that the obstacle detection area is wide and at a short distance. Conversely, when the vehicle is traveling at a high speed, The angle of divergence is reduced so that the obstacle detection area is narrowed and the distance is increased. In general, when the vehicle speed is high, it is often like traveling on a highway, and it is unlikely that humans will jump out under such circumstances. Therefore, by narrowing the detection area, the lighting on the shoulders or guardrails can be reduced. It is possible to improve the accuracy of obstacle detection by reducing the possibility of detecting an object such as a headlight of an oncoming vehicle that causes a false alarm.

[0004]

However, according to the above-described conventional vehicle obstacle detection device, the distance between the laser beam transmitting lens and the laser diode is mechanically adjusted by using the step motor. Therefore, large parts such as a step motor and a screw are required, which causes a problem of increasing the size of the entire apparatus.

Further, since the mechanical adjustment is performed, it takes time to change the detection area and the processing speed becomes slow.

The present invention has been made in view of the above, and an object of the present invention is to provide an obstacle detection device for a vehicle, which can change the detection range in an instant without increasing the size of the device. To do.

[0007]

In order to achieve the above object, the vehicle obstacle detection device according to claim 1 is arranged in a matrix with an optical system for collecting infrared rays from the front of the vehicle. Infrared detecting means for detecting the brightness of infrared rays condensed by the optical system by using a plurality of infrared detecting elements,
Scanning means for scanning a plurality of infrared detecting elements of the infrared detecting means and inputting infrared brightness from each infrared detecting element, and obstacle detecting means for detecting an obstacle from the infrared brightness input by the scanning means. An alarm output means for outputting an alarm when an obstacle is detected by the obstacle detection means, a vehicle speed detection means for detecting the vehicle speed of the host vehicle, and the scanning according to the vehicle speed detected by the vehicle speed detection means. Scanning change control means for changing the scanning range of the plurality of infrared detecting elements scanned by the means.

In the vehicle obstacle detection device according to a second aspect of the present invention, there is provided the vehicle obstacle detection device according to the first aspect, wherein the scanning change control means scans by the scanning means according to the vehicle speed detected by the vehicle speed detection means. In addition to changing the scanning range of the infrared detecting element, the number of scans is changed in inverse proportion to the scanning range.

[0009]

According to the present invention, there is provided a vehicle obstacle detecting device (claim 1).
The infrared detecting means uses a plurality of infrared detecting elements arranged in a matrix to detect the brightness of infrared rays from the front of the vehicle collected by the optical system, and the scanning means uses the plurality of infrared detecting elements. When the detecting element is scanned and the infrared brightness is input from each infrared detecting element, the obstacle detecting means detects the obstacle from the infrared brightness, and when the obstacle is detected, the alarm output means outputs an alarm. . on the other hand,
The scanning change control means changes the scanning range of the plurality of infrared detecting elements scanned by the scanning means according to the vehicle speed detected by the vehicle speed detecting means. In other words, the detection area of the obstacle detection means is changed by changing the scanning range of the scanning means.

Further, in the obstacle detecting device for a vehicle according to the present invention (claim 2), the scanning change control means scans a plurality of infrared detecting elements scanned by the scanning means in accordance with the vehicle speed detected by the vehicle speed detecting means. By changing the range and changing the number of scans in inverse proportion to the scan range, the signal-to-noise ratio is changed and the detectable distance is changed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the vehicle obstacle detecting device of the present invention will be described below in detail with reference to the drawings.

The construction of the vehicle obstacle detection device of this embodiment will be described with reference to FIG. The optical system 1 includes an optical system 101 that collects infrared rays from the front of the vehicle and a plurality of infrared detecting elements 201 (see FIG. 2) arranged in a matrix.
The infrared detecting section 102 as an infrared detecting means for detecting the brightness of the infrared rays collected by 01, and the plurality of infrared detecting elements 201 of the infrared detecting section 102 are scanned, and the infrared brightness is inputted from each infrared detecting element 201. A scanning unit 103 as a scanning unit, an obstacle detection unit 104 as an obstacle detection unit that detects an obstacle from the brightness of infrared rays input by the scanning unit 103, and an obstacle is detected by the obstacle detection unit 104. In this case, an alarm output unit 105 as an alarm output unit that outputs an alarm, a vehicle speed detection unit 106 as a vehicle speed detection unit that detects the vehicle speed of the host vehicle, and a vehicle speed detection unit 106.
A vehicle speed determination unit 107 for determining whether or not the vehicle speed detected in step S1 exceeds a preset value;
The scanning change control unit 108 changes the scanning range of the infrared detection unit 102 to be scanned by the scanning unit 103 according to the result determined in step S1 and changes the number of scans in inverse proportion to the scanning range.
Composed of and. The vehicle speed determination unit 107 and the scan change control unit 108 form a scan change control unit.

Next, referring to FIG. 2, the infrared detecting section 102
The configuration of will be described. As shown in the figure, the infrared detecting section 102 is composed of a plurality of infrared detecting elements 201 arranged in a matrix of M × N in which the number of horizontal elements is M and the number of vertical elements is N. In this embodiment, M
= 512, N = 512, the infrared detection elements 201 are arranged in a 512 × 512 matrix. Further, as the infrared detection element 201, a thermopile, HgCdTe, or the like can be used.

The operation of the above configuration will be described. Infrared rays incident from the front of the vehicle are condensed by the optical system 101 and guided to the infrared ray detecting section 102. The infrared detection element 201 receives the infrared rays that have entered the infrared detection elements 201.

On the other hand, when the vehicle speed detection unit 106 detects the vehicle speed of the host vehicle, it outputs it as the vehicle speed V _X to the vehicle speed determination unit 107. The vehicle speed determination unit 107 compares the vehicle speed V _x input from the vehicle speed detection unit 106 with a preset vehicle speed V _1, and when V _X <V ₁ , determines that the vehicle is traveling at low speed,
When V _X ≧ V ₁ , it is determined that the vehicle is traveling at high speed.

The scan change control unit 108 includes a vehicle speed determination unit 10
7 determines that V _X <V ₁ (that is, it is determined that the vehicle is traveling at a low speed), the scanning range scanned by the scanning unit 103 is, as shown in FIG.
0 to 511 and elements in the vertical direction N = 0 to 511 (that is, all elements of the plurality of infrared detection elements 201), and the vehicle speed determination unit 107 determines that V _X ≧ V ₁ (that is, determines as high speed running). In this case, the scanning range of the scanning unit 103 is set to N = 0 to 511 (the same as during low speed traveling), which is the entire area with respect to the vertical direction N of the infrared detection element 201, and M = with respect to the horizontal direction M. Elements up to 256 rows from 128 to 383, that is, 1/2 of low speed running
And As a result, the scanning range of the infrared detection unit 102 scanned by the scanning unit 103 is changed. Also, at this time,
The scan change control unit 108 determines the number of scans in inverse proportion to the scan range, and outputs it to the scan unit 103.

FIG. 3 is an explanatory diagram showing a change in the obstacle detection area due to the change in the scanning range. In the case of the present embodiment, when traveling at a low speed, the scanning angle is A degree, and the front B of the vehicle is
It collects infrared rays at a distance of m, and when traveling at high speed,
It collects infrared rays at a scanning angle of A / 2 degrees and a distance of 2 ^1/4 × Bm in front of the vehicle. The distance B when traveling at low speed
The details of the difference between m and the distance 2 ^1/4 × Bm at high speed will be described later.

Under the control of the scan change control unit 108, the scanning unit 103 has an infrared detecting element 201 of the infrared detecting unit 102 within a specified scanning range and a specified number of scans.
The infrared detection element 201 in the corresponding scanning range is scanned.
The brightness of the infrared light received at is output to the obstacle detection unit 104.

The obstacle detecting unit 104 is an infrared detecting unit 10.
The signal (luminance of infrared rays) input from 2 is amplified by an amplifier (not shown), converted into an analog / digital signal by an A / D converter (not shown), and then scanned in a single scanning range. The brightness of infrared rays input from the infrared detection element 201 is stored and held in a frame memory (not shown) as one piece of image data. At this time, if the scanning range of the scanning unit 103 is low speed traveling, 512 × 512
The infrared brightness input from the infrared detection element 201 of the matrix is stored as one piece of image data. Further, when the scanning range of the scanning unit 103 is high speed traveling, the brightness of the infrared rays input from the infrared detecting element 201 of the 256 × 512 matrix is stored as one image data.

Here, the scanning time and the detection area during low speed traveling and high speed traveling will be described. Total scan time is T,
Assuming that the scanning time per element is T _S and the scanning retrace time coefficient is τ, the total scanning time T is calculated by T = T _S MN / τ (1)

The difference in scanning time between low-speed traveling and high-speed traveling is that when the scanning time T _S per element is constant, for example, the number of horizontal scans during low-speed traveling is set to M = 512 and high-speed traveling is performed. If the number of horizontal scans at time is M ′ = 256, then M /
2 = M '. Therefore, the total scanning time during high-speed traveling is T / 2, where T is the total scanning time during low-speed traveling.
Becomes That is, during high-speed traveling, the time of image data created by one scan is half that during low-speed traveling.

Therefore, the obstacle detection unit 104 assigns a number like image data (1) and (2) in the order in which one piece of image data stored during high-speed traveling is stored, and stores it during low-speed traveling. Image data (a)
When the numbering is performed as described above, the two image data of the stored image data (1) and the stored image data (2) are integrated to obtain one image data (1 + 2). The total acquisition time of the 256 × 512 image data (1 + 2) is T, which is the same as the total scanning time of the 512 × 512 non-integrated image data (a) during low-speed traveling.

Here, the total scanning time T is sufficiently shorter than the vehicle speed.
It is stored in frame memory
Each of the image data (1) and (2) is almost the same image.
Become. As shown in Fig. 4, generally n frame memos
When adding the images stored in memory,
If there is no change between frames, the signal is coherent and noise
Can be considered as incoherent, so the signal
Each is added, but the noise is averaged over the whole and
The signal-to-noise ratio (S / N ratio) is n^1/2Doubled. Accordingly
In the case of the present embodiment, the image data (1) and the image data
Image data (1) obtained by integrating the two image data of (2)
The S / N ratio of +2) is 2 of the image data (a). ^1/2Double
It

Next, referring to FIG. 3, the obstacle detection area based on the vehicle speed will be described. In a general infrared detector, the entrance aperture area of the optical system is A, the target radiation amount is I, the transmittance of the optical path between the sensors is τ ₀ , the transmittance inside the optical system is τ ₁ , and the sensitivity of the sensor is r, the noise of the effective value V _n, the maximum distance that the infrared detecting device can detect the target is R, at this time of the signal-to-noise (S / n) is calculated by equation (2). (S / N) = (AIrτ ₀ τ ₁ ) / (V _n R ² ) (2)

The signal-to-noise (S / S) minimum required for the vehicle obstacle detection device of this embodiment to detect an obstacle.
N) ₁ is calculated by the equation (3) like the signal-to-noise used in a general infrared detector. (S / N) ₁ = (AIrτ ₀ τ ₁ ) / (V _n R ² ) ... (3)

Here, the signal-to-noise (S / N) ₂ is (S / N) ₂ when the S / N of the data at the distance R becomes n ^1/2 times the original data as described above. = (N ^1/2 AIrτ ₀ τ ₁ ) / (V _n R ² ) ... (4) Since the minimum S / N required for the vehicle obstacle detection device of this embodiment to detect an obstacle is (S / N) ₁ , (S / N) ₂ = (S / N) ₁ ... … (5) Therefore, the maximum distance R ′ at which the obstacle can be detected is given by the equation (7). (N ^1/2 AIrτ ₀ τ ₁ ) / (V _n R ² ) = (AIrτ ₀ τ ₁ ) / (V _n R ′ ² ) ... (6) R ′ = n ^1/4 R ...... (7)

That is, the detection distance is n ^1/4 times as large as when the images are not integrated. In the case of this embodiment, since n = 2, the obstacle detectable distance of V _X > V ₁ during high speed traveling is more horizontal than the obstacle detectable distance of V _X <V ₁ during low speed traveling. It becomes 1/2 times and the distance becomes 2 ^1/4 times. Therefore, as shown in FIG.
Then, the distance when traveling at high speed is 2 ^1/4 × Bm.

The obstacle detection unit 104 operates as described above.
Based on the obtained image data (1 + 2) or image data (a)
Then, the obstacle is detected. Here, the obstacle detection process
Regarding the time it takes for the reason,
By comparison, the detection range for high-speed running is lower than that for low-speed running.
Is halved in the horizontal direction, the number of image integrations is 2
Times (generally 1 / n times the number of integration times is n times),
S / N ratio of image data (1 + 2) at the same distance runs at low speed
N for line time^1/2Doubled and the detectable distance is n ^1/4Double
Become. Therefore, in either case, the obstacle detection unit 104
Obtains image data (1 + 2) or image data (a)
The total time up to
The time required for the reason is the same.

Since a known technique can be applied to the obstacle detection processing method in the obstacle detection unit 104, detailed description thereof will be omitted. However, generally, the temperature of a human being, for example, the temperature of 21 ° C. Below, it is checked whether the infrared brightness value is between the upper limit value and the lower limit value including this value with 32 ° C. as the reference temperature, and the infrared brightness value between the upper limit value and the lower limit value is checked. When there is a value, it is detected that a person (obstacle) is present in front.

Finally, when the obstacle detection unit 104 detects an obstacle, the alarm output unit 105 issues a warning to the driver by means of a buzzer, a display or the like provided in the alarm output unit 105.

As described above, according to this embodiment, based on the vehicle speed detected by the vehicle speed detection unit 106, the infrared detection unit 10
Since the second detection area is changed, there is no delay time due to the change of the obstacle detection area, and the overall processing speed can be improved. Further, as the detection area is changed, the signal-to-noise ratio is changed by integrating the number of signals inversely proportional to the scanning range, and the detectable distance is changed. Therefore, the obstacle detection area is narrow and the distance is long. Can be

Further, since the detection area is changed by an electric operation, the entire apparatus can be downsized. Furthermore, by changing the detection range, unnecessary obstacles need not be detected, and the occurrence rate of false alarms can be reduced.

[0033]

As described above, in the vehicle obstacle detection device (Claim 1) of the present invention, the infrared detecting means is an optical system using a plurality of infrared detecting elements arranged in a matrix. When the brightness of infrared rays from the front of the collected vehicle is detected, the scanning means scans a plurality of infrared detecting elements of the infrared detecting means, and the brightness of infrared rays is inputted from each infrared detecting element, the obstacle detecting means An obstacle is detected from the brightness of infrared rays, and an alarm output means outputs an alarm when the obstacle is detected. At this time, the scan change control means
In order to change the scanning range of the plurality of infrared detecting elements scanned by the scanning means according to the vehicle speed detected by the vehicle speed detecting means,
In other words, since the detection area of the obstacle detection means is changed by changing the scanning range of the scanning means, the size of the device is not increased and the detection range can be changed instantaneously. An obstacle detection device can be provided.

In the vehicle obstacle detection device of the present invention (claim 2), the scanning change control means scans a plurality of infrared detecting elements which the scanning means scans in accordance with the vehicle speed detected by the vehicle speed detecting means. By changing the range and changing the number of scans in inverse proportion to the scan range, the signal-to-noise ratio is changed and the detectable distance is changed, so that there is no increase in the size of the device, and It is possible to provide an obstacle detection device for a vehicle that can change the detection range in an instant.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a vehicle obstacle detection device of the present embodiment.

FIG. 2 is a configuration diagram showing an infrared detection unit of the present embodiment.

FIG. 3 is an explanatory diagram showing an obstacle detection area of the vehicle obstacle detection device of the present embodiment.

FIG. 4 is an explanatory diagram showing a process of image data of an obstacle detection unit.

[Explanation of symbols]

101 Optical System 102 Infrared Detector 103 Scanning Unit 104 Obstacle Detecting Unit 105 Alarm Output Unit 106 Vehicle Speed Detecting Unit 107 Vehicle Speed Determining Unit 108 Scan Change Control Unit 201 Infrared Detecting Element

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Claims (2)

[Claims] 1. An infrared system for collecting infrared rays from the front of the vehicle, and an infrared detecting means for detecting the brightness of the infrared rays collected by the optical system by using a plurality of infrared detecting elements arranged in a matrix. Scanning means for scanning a plurality of infrared detecting elements of the infrared detecting means and inputting infrared brightness from each infrared detecting element, and obstacle detection for detecting an obstacle from the infrared brightness input by the scanning means Means, an alarm output means for outputting an alarm when an obstacle is detected by the obstacle detection means, a vehicle speed detection means for detecting the vehicle speed of the own vehicle, and the vehicle speed detected by the vehicle speed detection means. An obstacle detection device for a vehicle, comprising: scan change control means for changing a scanning range of the plurality of infrared detection elements scanned by the scanning means. 2. The scanning change control means changes the scanning range of the plurality of infrared detecting elements scanned by the scanning means according to the vehicle speed detected by the vehicle speed detecting means, and is inversely proportional to the scanning range. The vehicle obstacle detection device according to claim 1, wherein the number of scans is changed.