JPH09145828A - Automatic door sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic door sensor that can discriminate an automatic door front passing person from an automatic door passing person. SOLUTION: In an automatic door sensor generating a door opening/closing control signal referring to the level of reflected wave from a reflecting body, a mixer part 4 detects the Doppler deviation of the reflected wave. When the Doppler deviation is lowered, a multiplying part 11 permits the generation of a door opening/closing control signal, judging the reflecting body to be a door passing person. Otherwise the multiplying part 1 inhibits the generation of the door opening/closing control signal, judging the reflecting body to be a door front passing person.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic door sensor for generating a door opening / closing signal by referring to the level of a reflected wave from a reflector.

[0002]

2. Description of the Related Art As a method for opening and closing an automatic door, a method using an ultrasonic sensor, an infrared sensor, a strain sensor or the like is used.

A method using an ultrasonic sensor is a method of detecting a reflected wave from an object in a detection area and controlling opening / closing of a door when the level of the reflected wave exceeds a threshold value.

The method using an infrared sensor is a method of controlling opening and closing of a door by temporarily blocking infrared rays when an object passes through a detection area, and the method using a strain sensor is This is a method in which a material whose electric resistance greatly changes due to deformation within the elastic limit is laid in the detection area, and opening / closing of the door is controlled by a change in electric resistance that occurs when an object passes through the detection area.

[0005]

In the above-mentioned conventional technique, since the door opens and closes only when an object passes through the detection area, a person who simply passes in front of the automatic door (hereinafter referred to as "automatic door front"). A person who passes through an automatic door (hereinafter referred to as "passer")
It is not possible to make a judgment as "automatic door passer"), and there are drawbacks such as making unnecessary use of nerves to the people in the room due to unnecessary opening and closing of the door, and reducing the efficiency of heating and cooling in the room. .

Therefore, an object of the present invention is to provide an automatic door sensor capable of distinguishing between an automatic door front passer and an automatic door passer.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an automatic door sensor for generating a door opening / closing control signal by referring to a level of a reflected wave from a reflector, and a Doppler deviation detecting a Doppler deviation of the reflected wave. When the Doppler shift is reduced, the movement detection means determines that the reflector is a door passer and allows the door opening / closing control signal to be generated. Otherwise, it is determined that the reflector is a door front passer. And a determination means for prohibiting the generation of the door opening / closing control signal.

The present invention also provides a transmitter for generating a transmission signal, a transmitter for emitting an ultrasonic wave in response to the transmission signal, and a receiver for generating a reception signal in response to a reflected wave based on the ultrasonic wave. A mixer unit for generating a Doppler frequency by comparing the frequency of the ultrasonic wave and the frequency of the reflected wave according to the transmission signal and the reception signal, and a frequency / voltage for converting the Doppler frequency into a DC voltage proportional thereto. A conversion unit, a differential addition unit that differentiates the DC voltage to generate a complement component of the DC voltage, adds the complement component to the DC voltage to generate an added output voltage, based on a peak value of the added output voltage A first peak-hold section for generating a threshold level, a first comparator section for comparing the added output voltage with the threshold level to generate a first comparison result signal, and the reflection Second peak hold section for generating a peak level signal representing the peak value of the second peak value, a second comparator section for comparing the peak level signal with a reference threshold level to generate a second comparison result signal, and the first and second The automatic door sensor is characterized by including a multiplication unit that generates a door opening / closing control signal as a second comparison result signal input.

Further, according to the present invention, there is provided an automatic door opening / closing device comprising the automatic door sensor and door driving means for driving the door in response to the door opening / closing control signal.

Further, according to the present invention, there is provided an automatic door including the automatic door opening / closing device and a door driven by the automatic door opening / closing device.

[0011]

When the reflector moves toward the automatic door, the Doppler shift detecting means detects the Doppler shift of the reflected wave from the reflector. When the reflector is a person who simply passes in front of the automatic door, the moving speed of the reflector does not decrease, and therefore the Doppler shift does not decrease. Therefore, at this time, it is determined that the reflector is a person who has passed the automatic door, and the generation of the door opening / closing control signal is prohibited.

On the other hand, when the reflector is a person passing by the automatic door, the moving speed of the reflector decreases as the reflector approaches the automatic door, and the Doppler shift decreases. Therefore, at this time, the level of the reflected wave is also referred to, the reflector is judged to be an automatic door passer, and a door opening / closing control signal is generated.

Thus, a person passing in front of the automatic door and a person passing through the automatic door are distinguished by utilizing the Doppler effect and the level of the reflected wave.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an automatic door sensor according to an embodiment of the present invention. Briefly described, this automatic door sensor generates a door opening / closing control signal by referring to the level of a reflected wave from a reflector, detects the Doppler shift of the reflected wave, and detects the Doppler shift. When the movement is lowered, the reflector is judged to be a door passer and the generation of the door opening / closing control signal is permitted, otherwise the reflector is judged to be a door front passer and the door opening / closing control signal It is configured to prohibit generation.

More specifically, the automatic door sensor is connected to the transmitter 1, the wave transmitter 2 connected to the transmitter 1, the wave receiver 3, the wave receiver 3 and the transmitter 1. Mixer section 4, frequency / voltage conversion section 5 connected to this mixer section 4, differential addition section 6 connected to this frequency / voltage conversion section 5, first peak hold connected to this differential addition section 6. Section 7, a first comparator section 8 connected to the first peak hold section 7 and the differential addition section 6, a second peak hold section 9 connected to the mixer section 4 described above,
A second comparator unit 10 connected to the second peak hold unit 9 and a multiplication unit 11 connected to the first and second comparator units 8 and 10 are included.

The transmitter 1 is for generating a transmission signal. The wave transmitter 2 is for radiating an ultrasonic wave according to the transmission signal. The wave receiver 3 generates a reception signal according to the reflected wave based on the ultrasonic wave. The mixer unit 4 compares the frequency of the ultrasonic wave with the frequency of the reflected wave according to the transmission signal and the reception signal to generate a Doppler frequency. The frequency / voltage converter 5 converts the Doppler frequency into a DC voltage proportional thereto. Differential adder 6
Differentiates the DC voltage to generate a complement component of the DC voltage and adds the complement component to the DC voltage to generate an added output voltage. The first peak hold unit 7 generates a threshold level based on the peak value of the added output voltage. The first comparator section 8 compares the added output voltage with the threshold level to generate a first comparison result signal. The second peak hold unit 9 generates a peak level signal representing the peak value of the reflected wave. The second comparator section 10 compares the peak level signal with a reference threshold level to generate a second comparison result signal.
The multiplication unit 11 generates a door opening / closing control signal as the first and second comparison result signal inputs.

The automatic door opening / closing device is constituted by the automatic door opening / closing device and the door driving means (not shown) for driving the door in response to the door opening / closing control signal. It goes without saying that an automatic door is constituted by a driven door (not shown).

The automatic door sensor will be described in more detail below.

The transmitter 1 produces a transmission signal having a constant frequency f ₀ and continuously outputs it to the wave transmitter 2.

Assuming that the frequency of the ultrasonic wave radiated from the transmitter 2 is f ₀ and the Doppler shift frequency of the reflected wave from the approaching or receding reflector is f ₀ ± f ₁ , the mixer unit 4 transmits the transmission frequency f. ₀ and the reflected wave frequency f ₀ ± f ₁ are compared, and the output Doppler frequency becomes | f ₁ | (a in FIG. 2).
See).

The frequency / voltage converter 5 converts the Doppler frequency | f ₁ | into a proportional DC voltage (see b in FIG. 3).

The differential adder 6 differentiates the converted DC voltage to generate the complement component of the output of the frequency / voltage converter 5. (See c in FIG. 3) By adding this and the output of the frequency / voltage conversion unit 5, a constant level DC voltage is generated regardless of the velocity azimuth of the reflector. In the first peak hold unit 7, the peak value of the output level of the differential addition unit 6 is fixedly output, and the level is lowered at a constant ratio, so that the threshold level L ₁ of the first comparator unit 7 is changed. make. This is an output pattern similar to the DC voltage when the speed does not decrease like a person passing by in front of the door.

The first comparator section 8 has a DC voltage corresponding to the Doppler frequency | f ₁ | and a threshold level L ₁
And the waveform is converted into a rectangular wave signal so that it becomes low (Lo) when the DC voltage level is higher than the threshold level L ₁ and high (Hi) when the DC voltage level is lower than the threshold level L ₁ .

On the other hand, the second peak hold unit 9 follows the peak value of the level of the reflected wave obtained from the reflector and outputs it as a DC voltage. Therefore, the level becomes large when the reflector approaches, and becomes small when the reflector moves backward.

The second comparator section 10 compares the DC voltage level corresponding to the reflected wave output from the second peak hold section 8 with the threshold level L _2, and outputs a high voltage when the DC voltage level is higher than the threshold level L _2. (Hi) Further, the waveform is converted into a rectangular wave signal so that it becomes low (Lo) when it is low.

The threshold level L ₂ is set between the reflected wave level obtained from a reflector approaching or receding in the detection area and the reflected wave level obtained without a reflector in the detection area. .

In the multiplication unit 11, both the output of the first comparator unit 8 and the output of the second comparator unit 10 are high (H
i), the output signal is high (Hi), and if the output is low (Lo) in either one, the output signal is low (L).
The o) rectangular wave signal is output.

By controlling the opening and closing of the automatic door by the output signal of the multiplication unit 11, it is possible to judge the automatic door front passer and the automatic door passer by utilizing the Doppler effect of ultrasonic waves and the level of the reflected wave. Become.

In the above structure, the wave transmitter 2 and the wave receiver 3 are integrally formed, and are arranged at the upper center of the entrance of the automatic door as shown in FIGS. 4a and 4b.

In the case of a person passing by in front of the automatic door (FIG. 4a), the output waveform of the reflector for the automatic door and each point in FIG. 1 at that time is as shown in FIG. 4a '.

In FIG. 4a ', (1) is the output signal of the frequency / voltage converter 5, which is the Doppler shift frequency | f ₁
| A considerable DC voltage does not fall below the threshold level L ₁ .

Therefore, the output signal of the first comparator section 8 becomes Lo as shown in (2).

On the other hand, the output of the second peak hold unit 9 is as shown in (3), and the level becomes maximum in front of the transducer.

At this time, as in (4), the second comparator section 10 compares the threshold level L ₂ with the above-mentioned signal, and the output signal becomes high (Hi) only in the portion exceeding the threshold level L ₂ .

Since the multiplication unit 11 multiplies the output (2) of the first comparator unit 8 and the output (4) of the second comparator unit 10, the output becomes low (Lo) as in (5).

As a result, the automatic door will not be opened or closed by a person passing by before the automatic door.

Next, in the case of an automatic door passer (FIG. 4b), the output waveform of the reflector for the automatic door and each point in FIG. 1 at that time is as shown in FIG. 4b '.

In FIG. 4b ', (1) is the output signal of the frequency / voltage converter 5, and the threshold level L ₁ is reached at a point when the DC voltage corresponding to the Doppler shift frequency | f ₁ | There are points to go down.

Therefore, the output signal of the first comparator section 8 changes from low (Lo) to high (Hi) at the point where the DC voltage falls below the threshold level L ₁ as shown in (2).

On the other hand, the output of the second peak hold unit 9 is as shown in (3), and the level becomes maximum in front of the transducer.

At this time, as in (4), in the second comparator section 10, the threshold level L ₂ is compared with the above signal, and the output signal becomes high (Hi) only in the portion exceeding the threshold level L ₂ .

Since the multiplication unit 11 multiplies the output (2) of the first comparator unit 8 and the output (4) of the second comparator unit 10, only the portion where both outputs are high (Hi) as in (5). The output goes high (Hi).

In response to this, the door driving means (not shown) opens the door when decelerating in the vicinity of the front of the automatic door to allow an automatic door passenger to enter the room.

In the above description, the case where the ultrasonic wave is used has been described. However, other signal mediums such as radio waves and light, which are accompanied by the Doppler phenomenon, can be similarly used.

[0046]

As described above, according to the present invention, the automatic door can be opened / closed by the Doppler shift frequency and the level of the reflected wave included in the reflected wave from the reflector approaching or receding in the detection area. By controlling, it becomes possible to provide an automatic door sensor having a function of determining whether the reflector is an automatic door front passer or an automatic door passer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an automatic door sensor according to an embodiment of the present invention.

FIG. 2 is a diagram showing an output waveform of a mixer unit included in the automatic door sensor of FIG.

3 is a diagram showing output waveforms of a frequency / voltage conversion unit and a differential addition unit included in the automatic door sensor of FIG.

FIG. 4 is a timing chart of the automatic door sensor of FIG.

[Explanation of symbols]

1 transmitter 2 transmitter 3 receiver 4 mixer 5 frequency / voltage converter 6 differential adder 7 first peak hold 8 first comparator 9 second peak hold 10 second comparator 11 Multiplier L ₁ Threshold level of first comparator L ₂ Threshold level of second comparator

Claims (4)

[Claims] 1. An automatic door sensor for generating a door opening / closing control signal by referring to a level of a reflected wave from a reflector,
Doppler shift detection means for detecting the Doppler shift of the reflected wave, and when the Doppler shift is reduced, it is determined that the reflector is a door passer, and the generation of the door opening / closing control signal is allowed, otherwise. An automatic door sensor, comprising: a determination unit that determines that the reflector is a person who has passed through the door and prohibits generation of the door opening / closing control signal. 2. A transmitter that generates a transmission signal, a transmitter that radiates an ultrasonic wave according to the transmission signal, a wave receiver that generates a reception signal according to a reflected wave based on the ultrasonic wave, and the transmission signal. And a mixer unit that generates a Doppler frequency by comparing the frequency of the ultrasonic wave and the frequency of the reflected wave according to the received signal, a frequency-voltage conversion unit that converts the Doppler frequency into a DC voltage proportional thereto. Differentiating the DC voltage to generate a complement component of the DC voltage, adding the complement component to the DC voltage to generate an added output voltage, a threshold level based on the peak value of the added output voltage. A first peak hold unit for generating, a first peak hold unit for comparing the added output voltage with the threshold level, and
A first comparator section for generating a comparison result signal, a second peak hold section for generating a peak level signal representing the peak value of the reflected wave, and a second comparison for comparing the peak level signal with a reference threshold level. An automatic door sensor, comprising: a second comparator section for generating a result signal; and a multiplication section for generating a door opening / closing control signal as the first and second comparison result signal inputs. 3. An automatic door opening / closing apparatus, comprising: the automatic door sensor according to claim 1; and door driving means for driving a door in response to the door opening / closing control signal. 4. An automatic door, comprising: the automatic door opening / closing device according to claim 3; and a door driven by the automatic door opening / closing device.