JPS63134984A - Person number detector - Google Patents

Abstract

PURPOSE:To separate and count even plural human bodies which have formed a line in almost the same radial direction, by dividing an instantaneous visual field on an object surface, in the direction vertical to the scanning direction, and viewing separately plural divided instantaneous visual fields by plural infrared ray detecting elements. CONSTITUTION:Photodetecting parts of infrared ray detecting elements 2a, 2b are both turned to the upper mirror side, and also, its optical axis (visual field center) is placed on the same axis as a revolving shaft 11 of a rotary plate 10. Both cylindrical mirrors MA, MB have a concave surface in the rotational direction, and an instantaneous visual field in the rotational direction on an object surface is reduced narrowly. Also, these mirrors MA, MB are fixed to the rotary plate 10 at a certain angle to each other, therefore, when the rotary plate 10 rotates, the infrared ray detecting elements 2a, 2b scan the annular object surface within a range of visual field angles (theta1-theta2), (theta2-theta3), respectively. In such a way, the resolution in the rotational direction on the object surface is raised, and also, the resolution in the radial direction can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) 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.

(Background Art) The present inventors have already proposed a highly accurate number of people detection device that has a simple and inexpensive configuration and a wide detection area. Fig. 5 shows its configuration diagram. 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 stationary 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 of the determining section 5. It consists of an output section 6 that outputs information on the number of people from the signal, and is capable of detecting the number of people within a wide detection area with high precision.

FIG. 6 shows an example of a circular scanning optical system. As shown in FIG.
The rotary plate 10 is placed at a position, the rotating shaft 11 of the rotary plate 10 is placed on the field of view center C of the light-receiving surface of the infrared detection element 2, and the rotary plate 10 is rotated by a drive mechanism such as a motor. As shown in No. 61121 (1+), a rectangular slit A having a length La and a width Da is provided in the rotating plate 10, so that only the infrared rays radiated from the object surface B pass through the pickpocket 7l-A. is configured so that it is incident on the infrared detecting element 2. The instantaneous visual error on the object plane is similar to the shape of the slit A, and if the distance from the rotary plate 10 to the object plane B is Ra, then the instantaneous visual field length L v and the visual field width DV on the object plane are as follows. It becomes as follows.

Further, in the radial direction in circular scanning, if the instantaneous field of view is the viewing angle at which the object surface B is seen, θ is expressed as in the following equation.

The above-mentioned instantaneous field of view is circularly scanned with the field center C of the light-receiving surface of the infrared detection element 2 as an axis, and therefore, the total viewing angle looking into the object surface B by the circular scanning method is 2θ.

In FIG. 6, if a convex cylindrical lens is provided at the slit A, a desired optical gain can be obtained.

In addition, as another means for obtaining optical gain, as shown in FIG. There are also examples of configuration. The distance from the mirror surface of the cylindrical mirror M to the light receiving surface of the infrared detection element 2 is Rb, the distance from the mirror surface of the cylindrical mirror M to the 1st surface B is Ra, the mirror length of the cylindrical mirror M is Lm, the mirror Assuming that the width is C+++ and the diameter of the light-receiving surface of the infrared detection element 2 is d, the instantaneous visual field length Lv and visual field width Dv on the object surface are expressed by the following equations.

Therefore, by selecting an appropriate value Rb or d, a predetermined instantaneous field width Dv can be obtained, and by increasing the mirror width Dua of the cylindrical mirror M, the optical gain can be increased. In the radial direction in circular scanning, the viewing angle θ at which the instantaneous visual field looks at the object surface B is as shown in the following equation, and the total viewing angle is 2θ.

Although the optical system of this device can accurately count human bodies distributed radially by increasing the resolution in the scanning direction, it is difficult to count multiple human bodies lined up in the same radial direction. The problem was that it was difficult.

(Object of the invention) The present invention has been made in view of the above points, and
The purpose is to provide a number of people detection device with improved resolution in the radial direction and higher accuracy in measuring the number of people.

(Disclosure of the Invention) In the people detection device according to the present invention, in the circular scanning optical system 1, as shown in FIG. The plurality of divided instantaneous fields of view FA, F8 are divided into a plurality of infrared detection elements 2a,
2b, which can be viewed separately.

This increases the resolution in the radial direction, making it possible to separate and count multiple human bodies lined up in almost the same radial direction.

Large 110 = Figure 1 (a) is a schematic I3 configuration diagram when the scanning optical system of the people detection device according to the embodiment of the present invention is viewed from the side, and Figure 1 (b) is a rotating plate for circular scanning. 10 and the condensing cylindrical mirrors MA and M attached thereto. Both 2a and 2b are infrared detection elements for detecting infrared rays radiated from a human body to be detected, and are made of, for example, a pyroelectric effect sensor. Infrared detection elements 2a, 2b
The light-receiving portions of the two are all directed toward the upper mirror, and their optical axes (centers of field of view) are arranged coaxially with the rotation axis 11 of the rotation plate 10. The cylindrical mirrors MA and M both have concave surfaces in the direction of rotation, and have the effect of narrowing the instantaneous field of view in the direction of rotation on the object plane.

Furthermore, by fixing these mirrors MA, M to the rotary plate 10 at a certain angle to each other, the infrared detection element 2
A and 2b are designed to have a field of view F A + F B on the object plane by mirrors MA and M, respectively.

Therefore, when the rotary plate 10 rotates once, the infrared detection elements 2a and 2b have viewing angles (θ1 to θ2) and (θ2), respectively.
- θ3) is scanned. This makes it possible to improve the resolution in the rotational direction on the object plane while also obtaining resolution in the radial direction. In the illustrated example, two sets of infrared detection elements 2a, 2b
and Miller M.A.? Although vI B was used, the resolution in the radial direction can be further improved by using more infrared detection elements and mirrors.

Here, the circuit configuration of the number of people detection device using the optical system will be explained based on FIG. 2. Infrared detection elements 2a, 2b
The outputs are amplified by preamplifiers 3a and 3b and then input to bandpass filters 41a and 41b. As the infrared detection elements 2a and 2b, pyroelectric elements that do not require cooling and are inexpensive are used. Since this pyroelectric element contains many low frequency components as background noise, in the bandpass filters 41a and 41J,
In addition to cutting unstable low frequency components, unnecessary high frequency components are also cut to improve the S/N ratio. The outputs of the bandpass filters 41a and 41b are input to the A/D converter 42, A/D converted by the A/D converter 42, and output to the microcomputer constituting the determination section 5. The motor drive section 12 operates according to the control signal from the microcomputer, and the zero rotation period detection section 13 drives and stops the motor of the circular scanning optical system 1 as necessary, which synchronizes with the scanning of the circular scanning optical system 1. A synchronizing signal is outputted to the microcomputer constituting the determining section 5 for each rotation. The half-section part 5 is the rotation period detection part 13
The A/D converter 42 is operated based on the synchronization signal from the A/D converter 42, and waveforms are sequentially captured from the A/D converter 42 every rotation. In the determination unit 5, the output waveform when a human body does not exist within the detection area is stored in advance in the memory as reference waveform data. The input waveform input from the A/D converter 42 is compared with the reference waveform in the memory, and the presence or absence of a human body and the number of people are determined at the same time. In this example, a comparison operation is performed between the input waveform data and the 9-waveform data, the result is used as new comparison processing waveform data, local maximum values are detected in the comparison processing waveform data, and the number of local maximum values is calculated as the number of people. I'm counting. In the comparison processing waveform data, when the detected number of people is O, the current input waveform data is updated as reference waveform data and stored in the memory.

By performing comparison calculations with the input waveform data using the reference waveform data in this way, it is possible to detect the number of people with high precision without being affected by environmental changes within the detection area.

The output section 6 displays the number of people information based on the number of people information given from the judgment section 5. In a conference room or the like, the number of people or the degree of congestion is displayed outside the room so that others can grasp the status of indoor use. In addition, in rooms used by individuals, the indoor status is marked as "absent", "occupied", or "guest" based on the number of people information "0 people", "1 person", and "more than 2 Å". By displaying this information, others can easily and simply understand the indoor situation.Furthermore, various environmental facilities such as air conditioning can be operated stably and effectively based on the information on the number of people.

In this embodiment, the same number of preamplifiers 3a, 3b and bandpass filters 41a, 41b as the infrared detecting elements 2a, 2b are provided, but the output of the infrared detecting elements 2a, 2b is controlled by a changeover switch controlled by a microcomputer. It is also possible to combine the preamplifier and bandpass filter into one by switching at .

Figure 3 ( ) is a schematic configuration diagram of a scanning optical system used in a number of people detection device according to another embodiment of the present invention, viewed from the side;
FIG. 2B is a bottom view of the scanning optical system seen from below. In this embodiment, the optical axes (field centers) of the four infrared detection elements 2a to 2d are not located on the rotation axis 11 of the rotation plate 10,
With the optical axis parallel to the rotation axis 11 on a plane perpendicular to the rotation axis 11, and with the light receiving surface facing upward,
They are installed axially symmetrically at 90° intervals.

Further, in the cylindrical mirror MA□-MD attached to the rotary plate 10 for circular scanning, all of the infrared detection elements 28 to 2d sequentially form a substantially annular field of view F A, F B+ F C+ on the object plane. In order to be able to scan F D, mirrors MA and MO are fixed on the rotary plate 10 at 90° intervals, with the mirror MA at the innermost side of the rotary plate 10 and the mirror MO at the outermost side of the rotary plate 10. ing. With this configuration, as shown in 1k, the infrared detecting elements 2a-, 2d each change the field of view for the areas of the first to fourth quadrants on the object surface every time the rotary plate 10 rotates 90 degrees. It is possible to scan in the order of FA, FB+FC+Fo, and the entire field of view on the object surface can be scanned by the four infrared detection elements 2a to 2d in the sea where rotation [10 rotates once. Then, the resolution in the radial direction on the object surface can be improved without reducing the scanning speed and, by extension, the response time of the apparatus.

In the explanation of Table 1 and FIG. 3, four infrared detection elements 2a to 2d are used.
I showed an example of dividing the area in the radial direction into four using:
For example, if you want to use 6 infrared detection elements and divide them into 6 parts, you can install the infrared detection elements and mirrors at 60" intervals. Also, as described in the previous embodiment, mirrors MA to MD In order to improve the resolution in the scanning direction, it is desirable to use a cylindrical mirror having a concave surface in the scanning direction.

Next, FIG. 4 is a process diagram showing the circuit configuration of a device for detecting the number of people using the optical system. 28 to 2d are infrared detection elements, 3a to 3d are preamplifiers, and 41a to 41d are bandpass filters, consisting of a total of 4 channels,
Each is in charge of the 1st to 4th quadrant areas on the object plane.

The configuration and operation of the pond are the same as those in the previous embodiment, and will therefore be omitted.

Further, as in the previous embodiment, it is also possible to provide a changeover switch between the infrared detection element and the preamplifier, and configure the preamplifier and the bandpass filter into one channel.

(Effects of the Invention) As described above, the present invention provides an infrared receiving type people detection device that detects the number of people by detecting infrared rays emitted from a human body to be detected. Since a circular scanning optical system that is divided into directions is used, and the plurality of divided instantaneous fields of view are viewed separately by a plurality of infrared detection elements, the resolution in the radial direction can be improved. This makes it possible to separate and count multiple human bodies lined up in the same radial direction.
This has the effect of increasing the number of people counting.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic configuration diagram of an optical system used in a people detection device according to an embodiment of the present invention, FIG. 1(b) is a bottom view of the main parts of the same, and FIG. 2 is a circuit of the same embodiment. A block diagram showing the configuration, FIG. 3(a) is a schematic configuration diagram of the optical system used in the number of people detection device according to the embodiment of the present invention, FIG. 3(b) is a bottom view of the main parts of the same, and FIG. is a block diagram showing the circuit configuration of the same embodiment as above, FIG. 5 is a block diagram of the conventional example, and FIG. 6(a)
7(b) is a schematic diagram of the optical system used in the conventional example, FIG. ) is a bottom view of the main parts of the same as above. 1 is a circular scanning optical system, 2a to 2d are infrared detection elements, 3
a to 3d are preamplifier sections, 4 is a signal processing section, 5 is a judgment section,
6 is an output section, MA to MD are mirrors, and FA to FD are visual fields.

Claims (3)

[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 circular scanning optical system is an optical system that divides the instantaneous field of view on the object surface in a direction perpendicular to the scanning direction, and the infrared detection element separately divides the plurality of divided instantaneous fields of view. A number of people detection device characterized by having a plurality of infrared detection elements arranged so as to be visible. (2) The number of people detection device according to claim 1, wherein the plurality of infrared detection elements are arranged coaxially with the rotation axis of the circular scanning optical system. (3) The plurality of infrared detection elements are arranged in a plane perpendicular to the rotation axis of the circular scanning optical system and axially symmetrical with respect to the rotation axis. The number of people detection device described in section.