JP2988195B2 - Vehicle detection 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 vehicle detecting device for detecting the presence of a traveling vehicle and measuring the speed of the traveling vehicle.

[0002]

2. Description of the Related Art FIG. 12 is a block diagram showing the configuration of a conventional vehicle detecting device, and FIG. 13 is an explanatory diagram of the operation of FIG. In the figure, reference numeral 1 denotes a pulse modulation signal generating unit for generating a pulse modulation signal, 2 denotes a driver unit for turning on and off a current by an output of the pulse modulation signal generating unit 1, and 3 denotes a single LED that emits a single LED according to the current of the driver unit 2. A light receiving unit 4 for receiving light reflected from the vehicle or the road surface of light from the light emitting unit 3 and converting the light into a voltage; 5 a DC removing unit for removing a disturbance light component from a signal from the light receiving unit 4; Is a signal amplifier for comparing the signal from the amplifier 6 with a reference voltage, and 8 outputs a vehicle detection signal from the comparison result of the signal comparator. A vehicle detection unit 9 is a main propagation path of the light of the light emitting unit 3, 10 is a propagation path where light from the generation unit 3 is reflected on a vehicle or a road surface and reaches a light receiving unit, and 11 is a passing vehicle.

Next, the operation will be described. FIG. 12
Operation of the onset optical portion Te is emission shown in FIG. 13 (a), the non-emissive repeat. Light emitted from the light emitting unit 3 is collected and reflected by the passing vehicle 11 or the road surface via the main propagation path 9 shown in FIG. The reflected light is diffused and enters the light receiving unit 4 shown in FIG. 12 via the main propagation path 10 shown in FIG. The light incident on the light receiving unit 4 is a signal shown in FIG. 13B because extraneous light such as sunlight is superimposed thereon. FIG.
3B shows the output voltage of the light receiving unit 4 of the reflected light when the light emitting unit of FIG. 12 emits light, and the output voltage of the light emitting unit 4 of the reflected light when the light emitting unit of FIG. The DC removing unit 5 in FIG. 12 removes the DC component due to the disturbance light shown in FIG. When the vehicle 11 passes through the output of the DC removing unit 5, the output of FIG.
The waveform is as shown in FIG. In FIG. 13C, C indicates the reflection level of the road surface, and D indicates the reflection level from the vehicle 11. The signal comparison unit 7 in FIG. 12 compares the reflection level with a reference value E preset to a value higher than the reflection level c of the road surface shown in FIG. Be present. The vehicle detection unit 8 makes the vehicle detection signal significant when the vehicle is present, and prevents the detection signal from being broken by retaining the signal.

[0004]

Since the conventional vehicle detection device is constructed as described above, the reflection level becomes less than the reference value in a portion of the vehicle, such as a glass surface, where light is not reflected so that vehicle detection can be performed accurately. There was a case that could not be done. Also conventional
Vehicle detection devices cannot measure vehicle speed.
there were.

[0005] The present invention has been made to solve the above problems, vehicle detection possible the vehicle accurately detected
The aim is to obtain a device. The invention also relates to a vehicle.
The purpose is to obtain a vehicle detection device that can measure speed.
You.

[0006]

According to the present invention, there is provided a vehicle detecting apparatus comprising: a light emitting means for turning on and off light emission;
Receives the reflected light of the light emitted from the optical means from the target
A plurality of light receiving means, and turning on / off light emission of the light emitting means.
Output the difference of the light receiving signal of the light receiving means at the time
Adding the output signals of the minute detecting means and the difference detecting means.
Adding means for comparing the output signal of the adding means with a reference value;
And the output signal of the addition value comparing means.
Vehicle detecting means for detecting a vehicle more.
You.

The vehicle detection device according to the present invention has a light emitting device.
Light emitting means for turning on and off, and radiation emitted from the light emitting means.
Receiving means for receiving reflected light from a target object
Receiving the light when the light emission of the light emitting means is on or off.
Difference detecting means for outputting the difference between the light receiving signals of the light means;
Adding means for adding the output signal of the difference detecting means;
Addition value comparison means for comparing the output signal of the addition means with a reference value
And the output signal of the difference detecting means is compared with a reference value.
The level comparing means to be compared and the output signal of the added value comparing means.
The vehicle is detected by the output signal of the level comparison means
And vehicle detecting means.

[0008] In the vehicle detecting device according to the present invention, the difference
Speed detector that measures the speed of the vehicle based on the output signal of the detector
An output means is provided.

In the vehicle detecting device according to the present invention,
The addition value comparison means preliminarily calculates the addition value of the addition means.
To the set positive and negative reference values, and
The level comparing means calculates each output value of the difference detecting means.
Compare with pre-set positive and negative reference values
In addition, the vehicle detecting means may determine the sum of
Indicates that the output value of the difference detecting means is larger than the reference value.
In this case, the vehicle is detected as a vehicle.

[0010] The vehicle detection device according to the present invention is characterized in that the vehicle
Which output of the plurality of light receiving means is significant by both detection means
Light-receiving area selection method for changing the light-receiving area
A step is provided.

[0011]

[0012]

In the present invention, the light emission of the light emitting means is turned on,
The difference output of the light receiving signal of the light receiving
And compare the added value with a preset reference value
Then, the vehicle is detected based on the comparison result.

In the present invention, the ratio of the addition value comparing means
The vehicle is detected based on the comparison result or the comparison result of the level comparison means.
I do.

In the present invention, the difference detection means
The vehicle speed is measured from the vehicle detection time difference.

In the present invention, the added value of the adding means is
Compare with pre-set positive and negative reference values
And the output values of the difference detection means are set in advance.
The positive and negative reference values
The sum value of the stage or the output value of the difference detection means is the reference
If it is larger than the value, it is detected as a vehicle.

In the present invention, the plurality of light receiving means are provided.
Select whether the output signal of the
The area (vehicle detection area) is varied.

[0017]

[0018]

[Embodiment 1 ] An embodiment of the present invention will be described below with reference to the drawings. FIG.
Is a block diagram showing a configuration of a vehicle detection device according to the present invention.
FIG. 2 is a diagram illustrating the structure, and FIG. 3 is a diagram illustrating the operation thereof.
1, 2, and 11 are the same as those of the conventional apparatus. 12 is
It is composed of a plurality of LEDs and is simultaneously turned on by the driver unit 2.
The first light emitting portions 13 to 15 are the first light emitting portions 12
From the vehicle 11 or the road surface
1st to n-th light receiving units for converting to voltage, 16 to 18
Increases the output from the first to n-th light receiving units, respectively.
The first to n-th width portions, and 19 to 21 are the first to n-th width portions.
To remove the influence of extraneous light from the output of the amplifier
The first to n-th light-emitting units 12 that calculate the difference between when the light emitting unit 12 is on and when it is off
, The difference detection unit 22 of the first to n-th difference detection units
A signal switching unit that switches and holds the output in a time-sharing manner and outputs the signal.
3 is an A / D for digitizing a signal from the signal switching unit
The conversion unit 24 is provided with a signal from the A / D conversion unit 23 in advance.
A level comparison unit for comparing with a set reference voltage.
The presence or absence of a vehicle is detected from the comparison result of the
Add a hold to prevent vehicle detection signal cracking
The first vehicle detectors 26 to 28 are respectively the first to n-th
3 shows a propagation path of light incident on a light receiving unit. In FIG.
(A) is an arrangement of light receiving elements in the first to n-th light receiving units.
FIG. 2B is a plan view of FIG.
In the figure, reference numerals 29 to 31 denote first to n-th light receiving units 1.
First to n-th light receiving elements corresponding to 3, 14, 15;
Reference numeral 2 denotes a condenser lens that collects light.

Next, the operation will be described. In FIG. 3 (a)
In order to avoid light interference with adjacent oblique lines,
Each time a light pulse is emitted, the pause time is twice as long as n light emission pulses
I take the. In the adjacent lane, light is emitted n times during this pause
Synchronize to emit a pulse. Pal in Fig. 3 (a)
Approximately 2m irradiation composed of multiple LEDs based on modulation signals
The light emitting section having the region emits light and emits no light at the same time. This light
Disturbance such as reflection of sunlight reflected from the over-vehicle 11 or the road surface
The first to n-th receivers arranged as shown in FIG.
The light enters the optical elements 29 to 31 from the propagation paths 26 to 28. Entering
The emitted light is converted into a voltage by the first to n-th light receiving units 13 to 15.
This is converted into signals as shown in FIGS. Here
Is a reflection level due to disturbance light such as sunlight, and a is a light emitting unit 1.
2 shows the reflection level of light. First to n-th light receiving units 13
From the first to n-th amplifiers 16 to 18
The first to n-th difference detectors 19 to 21 increase the width.
Thus, only the component (a) in FIG. 3 (c) is extracted. Enter at this time
Calculate A using the value of B just before measuring the firing level
Of changing ambient light such as fluorescent light
Can be removed. Next, the signal switching unit 22 sets A for each light emission.
/ D conversion signal is converted from first to second and n-th difference detectors 1
The output is switched to 9 to 21 in a time sharing manner. This makes the road
From the first to n-th difference detectors 19 to 21 installed above
Signal line with the part after the A / D converter 23 installed on the roadside
Can be reduced. The switched signal is the difference of the next light receiving part.
It is held until the output is switched from the detection unit. This output
It is shown in FIG. Where c is the reflection level from the road surface,
D is the level of reflection from the vehicle, E is the vehicle every 5 seconds
Only when the output is not significant, the reflection level is averaged and the road surface level
At the comparison reference level,
is there. In the level comparing section 24, the output of the signal switching section 22
And the reflection level digitized by the A / D converter 23
Compare with the reference level E. In the first vehicle detection unit 25
Indicates that the vehicle detection output is significant when the reflection level exceeds the reference plane.
And the output at the time of non-light emission by adding about 100 ms hold
Prevents cracking of the power and at the same time as the windshield of a vehicle
The vehicle detection output is turned off at the part with very little reflection
And the vehicle detection output. As shown in FIG.
The above arrangement is achieved by placing
Eliminates the inability to detect by glass and detects vehicles stably
Wear.

Embodiment 2 FIG. FIG. 4 is a block diagram of another embodiment, and FIG. 5 is an operation explanatory diagram. In FIG. 4, the same reference numerals indicate the same functions as those of the conventional and the first embodiment. 33 is a first output from the A / D converter 23.
Signal adding unit that adds a to the light receiving element 29 to 31 of the n, 34 denotes an adder comparator for comparing a reference value signal from the signal addition unit 33. The output of the signal switching unit in FIG. 5A is the same as that in the first embodiment and FIG. 3F. The output of the signal switching unit 22 is digitized by the A / D conversion unit 23, and the output from the first to n-th difference detection units 19 to 21 is output to the signal addition unit 33.
Add with FIG. 5B shows the output of the signal adding unit 33. Here, nu is the total value of the additions from 〜 to リ. Is a reference value of the added value of the road surface level and the predetermined value, as in the first embodiment. The added value comparison unit 34 compares the output of the signal addition unit with the reference value. The first vehicle detector performs the same processing as in the first embodiment to detect the presence of a vehicle. By summing the outputs of all the light receiving elements, the same effect is obtained as when the light receiving area is increased by n times, and the S / N is improved.

Embodiment 3 FIG. FIG. 6 is a block diagram of another embodiment. 6, the same reference numerals indicate the same functions as those in the first and second embodiments. Reference numeral 35 denotes a vehicle detection unit which outputs a vehicle detection significance when one of the vehicle detection significance signal from the level comparison unit 24 and the vehicle detection significance signal from the addition comparison unit 34 is significant, and adds and retains the information. The level comparison improves the S / N by not using a signal from the light receiving element that is meaningless for detection, and the added value comparison has the advantage of improving the S / N by enlarging the light receiving area. Therefore, the vehicle can be accurately detected.

Embodiment 4 FIG. FIG. 7 is a block diagram of another embodiment, and FIG. 8 is an explanation of this. In FIG. 7, the same reference numerals indicate the same functions as those in the third embodiment. 36, the first light receiving element 29 measures the time t from when the output of the first light receiving portion 13 reaches the vehicle detection significance level until the output of the light receiving portion 15 of the n reaches the vehicle detection significance level The passing speed detecting unit calculates the speed v of the passing vehicle by dividing the distance x between the detecting region and the detecting region of the n-th light receiving element 31 by this time.

Embodiment 5 FIG. FIG. 9 is a block diagram of another embodiment, and FIG. 10 is an explanatory diagram of this. In FIG. 9, the same reference numerals indicate the same functions as in the fourth embodiment. Reference numeral 37 denotes an absolute level for performing the same processing as the first level comparing section 24 on the assumption that when the output from the A / D converter 23 is equal to or lower than the road surface level, the output is equal to or higher than the road surface corresponding to the absolute value level. The comparison unit 38 is the signal addition unit 3
3 is the same as the first addition / comparison unit 34 when the output of the vehicle is equal to or lower than the road surface level, and the absolute addition value comparison unit 39 performs the same processing as the first addition / comparison unit 34. Is a passing speed detecting unit. In FIG. 10B, the broken line is the absolute level, the solid line is the actual output, and the vehicle detection is significant when the absolute level exceeds the reference value E. This can be detected better accuracy in the vehicle which absorbs light such as a vehicle black.

Embodiment 6 FIG. FIG. 11 is a block diagram of another embodiment. In FIG. 11, the same reference numerals indicate the same functions as in the fifth embodiment. Reference numeral 40 denotes an area selection unit for selecting which of the first to n-th light receiving elements is used for vehicle detection, and is configured by a switch or the like. Thereby, the area in the vehicle traveling direction of the vehicle detection area can be adjusted by determining which of the light receiving elements is effective in the light receiving element configuration of FIG.
The region can be arbitrarily set to some extent irrespective of installation, and can be easily replaced with another type of existing vehicle detection device.

[0025]

According to the above manner the present invention, according to the present invention, the vehicle detection area widely because vehicle by using a plurality of light receiving portions
There is an effect that both detections can be accurately performed. The invention
Can detect both vehicle detection and vehicle speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 shows a light receiving element structure according to a first embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the first embodiment of the present invention.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a third embodiment of the present invention.

FIG. 7 is a block diagram showing a fourth embodiment of the present invention.

FIG. 8 is an operation explanatory diagram of Embodiment 4 of the present invention.

FIG. 9 is a block diagram showing a fifth embodiment of the present invention.

FIG. 10 is an operation explanatory view of Embodiment 5 of the present invention.

FIG. 11 is a block diagram showing a sixth embodiment of the present invention.

FIG. 12 is a block diagram showing a conventional vehicle detection device.

FIG. 13 is an operation explanatory diagram of a conventional vehicle detection device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pulse modulation signal generating section 2 driver section 3 second light emitting section 4 light receiving section 5 direct current removing section 6 amplification section 7 signal comparing section 8 vehicle detecting section 9 main propagation path 10 propagation path 11 passing vehicle 12 first light emitting section Reference Signs List 13 1st light receiving section 14 2nd light receiving section 15 nth light receiving section 16 1st widening section 17 2nd widening section 18 nth widening section 19 1st difference detecting section 20 2nd Difference detection unit 21 n-th difference detection unit 22 signal switching unit 23 A / D conversion unit 24 level comparison unit 25 first vehicle detection unit 26 first propagation path 27 second propagation path 28 n-th propagation path 29 1st light receiving element 30 2nd light receiving element 31 nth light receiving element 32 condenser lens 33 signal addition unit 34 addition value comparison unit 35 second vehicle detection unit 36 first passing speed detection unit 37 absolute level comparison unit 38 Absolute addition value comparison unit 39 Second pass Degree detecting unit 40 area selection unit

Continuation of the front page (56) References JP-A-1-96581 (JP, A) JP-A-58-87483 (JP, A) JP-A-54-148551 (JP, A) JP-A-61-90299 (JP) JP-A-54-34856 (JP, A) JP-A-62-217176 (JP, A) JP-A-5-119147 (JP, A) JP-A-51-35355 (JP, A) 58-10149 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01S 7/42-7/51 G01S 17/00-17/95 G08G 1/00

Claims (5)

(57) [Claims] 1. A light emitting means for turning on and off light emission,
The reflected light from the target of the light emitted from the light emitting means
A plurality of light receiving means for receiving light;
The difference between the light receiving signals of the light receiving
Difference detecting means for outputting the output signal of the difference detecting means.
Adding means for adding, and an output signal of the adding means as a reference value
And an output of the additional value comparing means.
A vehicle detecting device, comprising: a vehicle detecting means for detecting a vehicle based on a force signal . 2. A light emitting means for turning on and off light emission,
The reflected light from the target of the light emitted from the light emitting means
A plurality of light receiving means for receiving light;
The difference between the light receiving signals of the light receiving
Difference detecting means for outputting the output signal of the difference detecting means.
Adding means for adding, and an output signal of the adding means as a reference value
And an output of the difference detecting means.
Level comparing means for comparing each signal with a reference value;
The output signal of the added value comparison means or the output signal of the level comparison means
Vehicle detecting means for detecting a vehicle based on the output signal.
A vehicle detection device characterized by the above-mentioned . 3. A vehicle according to an output signal of said difference detecting means.
Speed detecting means for measuring the speed of the vehicle
The vehicle detection device according to claim 1 . 4. The addition value comparison means according to claim 1 , wherein
Positive reference value and negative reference value with preset addition value
Value, and the level comparing means detects the difference.
Each output value of the means is set to a predetermined positive reference value and
The vehicle detection means compares the value with the negative reference value.
The added value of the means or the output value of the difference detection means
If it is larger than the reference value, it is detected as a vehicle.
The vehicle detection device according to claim 2 . 5. The plurality of light receiving means in the vehicle detecting means.
The light receiving area is varied depending on which output of
Characterized by having light receiving area selecting means for
Item 5. The vehicle detection device according to Item 4.