JPH01216494A - People number detector - Google Patents

Abstract

PURPOSE:To improve the detecting accuracy of the title detector by forming plural instantaneous visual fields divided in the radius direction of the visual field, taking out the instantaneous visual field on a remote distance side as a separate signal waveform, and judging the number of people. CONSTITUTION:The instantaneous visual field formed by a circular scanning optical system K is divided in the radius direction of the whole visual field, and the length in the radius direction of an instantaneous visual field SB on the remote distance side is made shorter than the length in the radius direction of an instantaneous visual field SA. Further, infrared ray information from the respective visual fields SA and SB are alternately guided to infrared ray detecting elements at every half rotation of the circular scanning optical system 1, and based on an output obtained from the respective instantaneous visual fields, the number of the people is detected. Thus, the fluctuation of the detecting area due to the change of the temperature of a background can be made smaller, and the people number detector, whose detecting information is improved can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infrared receiving type people detection device that detects the number of people by detecting infrared rays emitted from a detected human body.

[Conventional technology]

Conventionally, a number of people detection device as shown in FIG. 7 has been proposed (Japanese Patent Application No. 281309/1982). This number of people detection device includes an infrared detection element 2, a circular scanning optical system 1 that circularly scans the field of view of the infrared detection element 2, a preamplifier 3 that amplifies the output signal of the infrared detection element 2, and a preamplifier 3 that amplifies the output signal of the infrared detection element 2. a signal processing section 4 that converts the output signal of the amplifier section 3 into a signal necessary for detecting the number of people; a determining section 5 that determines the number of people based on the output signal of the signal processing section 4; and an output signal of the determining section 5. The output unit 6 outputs information on the number of people from the sensor, and the number of people within a wide detection area can be detected with high accuracy.

In the judgment section 5 of this number of people detection device, the signal processing section 4
The number of people is determined based on the output signal. In the signal processing unit 4, an input waveform when a human body is not present in the detection area is stored in advance as a reference waveform, and the input signal is compared with the reference waveform to obtain a difference waveform between the two. This differential waveform is input to the judgment unit 5, and the presence or absence of a human body and the number of people are judged at the same time. Furthermore, by updating the input signal as a reference waveform when it is determined that a human body is not present, the system is less susceptible to environmental changes.

[Problem to be solved by the invention]

Such a people detection device requires a wide instantaneous field of view in the radial direction of the circular field of view, so for example, in the case of a wall-mounted type as shown in Figure 8, the distance between the mounting wall and the human body is D. Then, the comparison waveform between the reference waveform and the input waveform, that is, the relationship between the peak value of the waveform, which is information for determining the number of people, and the distance becomes as shown by curve E in FIG. 9.

Here, the peak value of the comparison waveform changes depending on the temperature change of the background such as the floor surface. Therefore, for example, if the background temperature increases, the peak value will decrease as shown by curve E° in FIG. Since the characteristics of the curve E° become more gradual as the distance increases, when trying to detect a human body at a constant darkness value TH, the detection area becomes smaller from D2 to Dl.

That is, since the detection area changes greatly depending on the state of the background, there is a problem in that the detection area cannot be clearly defined.

The present invention has been made in view of the above points, and its purpose is to provide a number of people detection device that reduces fluctuations in the detection area due to changes in background temperature and improves detection accuracy. It is in.

[Means to solve the problem]

The present invention includes an infrared detection element, a circular scanning optical system that circularly scans a field of view of the infrared detection element, a preamplification section that amplifies an output signal of the infrared detection element, and an output signal of the preamplification section. A number of people consisting of a signal processing section that converts into a signal necessary for detecting the number of people, a judgment section that judges the number of people based on the output signal of the signal processing section, and an output section that outputs number of people information from the output signal of the judgment section. In the detection device, the instantaneous field of view formed by the circular scanning optical system is divided in the radial direction of the entire field of view, and the radial length of the farthest instantaneous field of view is the radial length of the other instantaneous fields of view. It is characterized by making the distance shorter than the total, and preventing signals from each of the instantaneous visual fields from being input to the infrared detection element at the same time, and detecting the number of people based on the output obtained from each instantaneous visual field. shall be.

[Effect]

The number of people detection device of the present invention forms a plurality of instantaneous fields of view divided in the radial direction of the field of view, extracts the instantaneous field of view on the far side as a separate signal waveform, and determines the number of people.
Detection accuracy has been improved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on drawings showing one embodiment of the present invention.

FIG. 1 is a block diagram showing one embodiment of the present invention,
FIG. 2 is a side view showing the optical system according to the above embodiment. . Reference numeral 1 denotes a circular scanning optical system, which is composed of two optical systems including a mirror 11A and a mirror 11B.

That is, mirror 11A and mirror 11B are attached to rotating plate 10. The mirror 11A is a deformed toric mirror having a reflecting surface with a deformed toric surface, so that the instantaneous visual field formed on the floor surface is elongated in the radial direction of the visual field, as shown in FA in FIG. Mirror 11B
is a concave mirror with a long focal length, and its instantaneous field of view is F,
It becomes like a spot like this.

Here, the instantaneous visual field FA and the instantaneous visual field F8 are arranged to be on opposite sides with respect to the center line of the visual field. this is,
This is to prevent infrared rays from being incident on the infrared detecting element described later from the mirrors 11A and 11B at the same time.

The rotary plate 10 is attached to a motor 12 and rotates as the motor 12 rotates. As a result, the instantaneous field of view FA
The instantaneous field of view F is rotated, and a field of view S4 and a field of view S are obtained.

FIG. 4(a) is a side view of the field of view S^ and the field of view S when the number of people detection device K having the circular scanning optical system described above is attached to a wall surface H, and FIG. , 4th
Visual field SA and visual field S formed on floor surface Y corresponding to figure (a)! Indicates l.

Reference numeral 2 denotes an infrared detection element such as a pyroelectric element, which detects infrared rays emitted from the human body. Reference numeral 3 denotes a preamplifier section that amplifies the output signal of the infrared detecting element 2 to a size that can be processed by a signal processing section to be described later.

A signal processing section 4 converts the output signal of the preamplification section 3 into a signal necessary for detecting the number of people. Reference numeral 5 denotes a determining section that determines the number of people based on the output signal of the signal processing section 4. In the signal processing unit 4, the input waveform when a human body is not present in the detection area is stored in memory as a reference waveform in advance, and the input waveform is compared with the reference waveform in the memory, and judgment is made based on the difference waveform. In section 5, the presence or absence of a human body and the number of people are simultaneously determined. Reference numeral 6 denotes an output section that outputs the number of people information from the output signal of the judgment section 5.

Reference numeral 7 denotes a synchronous circuit section which obtains rotation information of the rotary plate 10 from the circular scanning optical system 1 and sends this rotation information to the determination section 5. Based on this rotation information, the judgment unit 5 converts the signal input from the signal processing unit 4 to the judgment unit 5 necessary for detecting the number of people to the mirror 11A.
It is determined whether the optical system is based on the optical system consisting of or the optical system consisting of the mirror 11B.

Next, the operation of this embodiment will be explained. Infrared information within the field of view is collected by the circular scanning optical system 1 and sent to the infrared detection element 2.
guided by.

Here, when the people detection device K is attached to a wall surface H as shown in FIG. guided by.

It is converted into an electric signal by the infrared detection element 2, and then sent to the preamplifier 3.
The signal is amplified to the signal necessary for detecting the number of people.

The signal processing unit 4 generates a reference waveform stored in advance (see FIG. 5).
a)) and the input waveform (Fig. 5(b))
(C)).

In the determination unit 5, rotation information of the rotary plate 10 is input from the synchronization circuit unit 7, and in the difference waveform from the signal processing unit 4, whether the visual field SA on the near side or the visual field S on the far side is determined. After determining this, the presence or absence of a human body and the number of people can be determined. The example in FIG. 5 shows a case where one person exists within the visual field SI.

Here, the relationship between the peak value of the comparison waveform between the reference waveform and the input waveform and the distance from the number of people detection device K is as shown in FIG. The signal obtained from the mirror 11A, that is, the signal from the near field of view SA, exhibits the characteristics of curve A in the figure.
Further, the signal obtained from the mirror 11B, that is, the field of view S on the far side.

The signal from the signal shows the characteristic of B in the figure. Curve A in the figure.

, B1 indicate, for example, a change in the above characteristics when the background temperature increases. As is clear from the figure, the characteristic of the long-distance field of view Sl is that the peak value changes little with respect to distance even when the background temperature changes, so even if a human body is detected with a constant threshold TH, the detection area will hardly change. It is.

The presence of a human body and the number of people information obtained by the judgment unit 5 are
The output unit 6 outputs the signal to the outside.

In the above embodiments, a case has been described in which the field of view is divided into two, but it goes without saying that the field of view may be divided into three or more.

〔Effect of the invention〕

As described above, according to the present invention, there is provided an infrared detection element, a circular scanning optical system that circularly scans the field of view of the infrared detection element, a preamplifier that amplifies the output signal of the infrared detection element, and a preamplifier that amplifies the output signal of the infrared detection element. a signal processing section that converts the output signal of the stationary amplification section into a signal necessary for detecting the number of people; a determining section that determines the number of people based on the output signal of the signal processing section; and outputting the number of people information from the output signal of the determining section. In the people detection device, the instantaneous field of view formed by the circular scanning optical system is divided in the radial direction of the entire field of view, and the length in the radial direction of the instantaneous field of view on the farthest distance side is calculated from the other instantaneous fields of view. shorter than the sum of the lengths in the radial direction, the signals from each instantaneous field of view are not input to the infrared detection element at the same time, and the number of people is detected based on the output obtained from each instantaneous field of view. As a result, it was possible to suppress fluctuations in the field of view due to changes in background temperature, etc., and provide a number of people detection device with improved detection accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a side view showing a circular scanning optical system according to the above, FIG. 3 is a schematic diagram showing a field of view according to the above, and FIG. is a schematic diagram of the field of view when the infrared detection element is mounted on a wall surface in the same as above, FIG. 5 is a waveform diagram according to the same as above, and FIG. FIG. 7 is a block diagram showing a conventional example; FIG. 8 is a side view of the same as above when the infrared sensing element is mounted on a wall; FIG. 9 is a schematic diagram showing the field of view according to the above. It is. 1-Circular scanning optical system 2-・Infrared detection element 3-・Preamplifier section 4--Signal processing section 5-・Judgment section
6-・Output section 7-・-Synchronization circuit section 10-
...Rotating plate 11A--Mirror 11B--
Mirror Patent Applicant Matsushita Electric Works Co., Ltd. Agent Patent Attorney Toshimaru Takemoto (and 2 others) Figure 1 Figure 2 Figure 3 ■ Figure 4 Figure 5 Figure 6 Figure 1-Figure 7 Figure 8 Figure 9 Aim, D2 distance

Claims (1)

[Claims] (1) An infrared detection element, a circular scanning optical system that circularly scans the field of view of the infrared detection element, a preamplification section that amplifies the output signal of the infrared detection element, and an output signal of the preamplification section that A number of people detection unit that includes a signal processing unit that converts into a signal necessary for detection, a determination unit that determines the number of people based on the output signal of the signal processing unit, and an output unit that outputs number of people information from the output signal of the determination unit. In the apparatus, the instantaneous field of view formed by the circular scanning optical system is divided in the radial direction of the entire field of view, and the length in the radial direction of the instantaneous field of view on the farthest distance side is
shorter than the sum of the radial lengths of the other instantaneous fields of view, and the signals from each of the instantaneous fields of view are not input to the infrared detection element at the same time, and based on the output obtained from each instantaneous field of view. A device for detecting the number of people, characterized in that the number of people is detected by