JP2012002514A - Human body detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a human body detector which has no limit of a detection range by using ultrasonic wave to detect air flow.SOLUTION: A human body detector comprises; a pair of ultrasonic vibrators 1, 2 capable of transmitting and receiving an ultrasonic wave signal; a propagation time measuring unit 4 for measuring the propagation time of ultrasonic wave from when the ultrasonic wave signal is transmitted from one ultrasonic vibrator until when the ultrasonic wave signal which propagates a fluid passing in a measuring channel 3 is received by the other ultrasonic vibrator; a flow rate operation unit 7 for determining a flow rate of the air filling between the ultrasonic vibrators 1, 2 by operating from the propagation time; and a human body detector 8 for judging the presence/absence of people from the flow rate operated in the flow rate operation unit 7.

Description

  The present invention relates to a human body detection device that detects an intrusion of a person by detecting a change in air flow using a pair of ultrasonic transducers capable of transmitting and receiving.

  As a conventional human body detection device, for example, there is a device that detects the presence or absence of a person by detecting the presence or absence of blocking of an infrared beam by using infrared light receiving and emitting elements arranged facing each other at a distance (for example, Patent Document 1). Other detection methods include body temperature detection using a pyroelectric sensor and distance measurement using ultrasonic waves or infrared rays (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 04-161831 Japanese Patent Laid-Open No. 08-329358

  However, the conventional configuration disclosed in Patent Document 1 has a problem that the installation direction and the detection range are limited because the intruder cannot be detected unless the infrared rays emitted by the intruder are blocked. Further, even in the configuration using the ultrasonic wave or pyroelectric sensor disclosed in Patent Document 2, since the intruder cannot be detected unless the detection unit faces the intruder, there is a problem that the detection range and installation are limited. Had.

  The present invention solves the above-described conventional problems, and detects an amount of change in the flow of air in a sealed space or the like to provide an ultrasonic human body detection device with no restrictions on the installation direction or detection range. The purpose is to provide.

  In order to solve the above-described conventional problems, a human body detection device according to the present invention includes a pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals arranged at predetermined intervals on a flow path, and one of the ultrasonic transducers And a propagation time measuring unit for measuring the propagation time of the ultrasonic wave until the other ultrasonic transducer receives the ultrasonic signal transmitted through the air in the flow path, and calculating the ultrasonic wave from the propagation time by calculation. The flow rate calculation unit calculates the flow rate of air that fills the space between the acoustic transducers, and the human body detection unit determines the presence or absence of a person based on the flow rate calculated by the flow rate calculation unit.

  As a result, it is possible to provide a human body detection device capable of detecting a person without any limitation in the installation direction and the detection range.

  Since the human body detection apparatus of the present invention can detect a minute air flow without any limitation in the installation direction or detection range, it can realize intruder detection in a wide range.

Configuration diagram of ultrasonic flowmeter in Embodiment 1 of the present invention Configuration diagram of ultrasonic flowmeter in embodiment 2 of the present invention The figure which shows the normal pattern and abnormal pattern in Embodiment 2 of this invention

  The first invention is a pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals arranged at predetermined intervals on the flow path, and is transmitted from one of the ultrasonic vibrators and propagates air in the flow path A flow time measurement unit that measures the propagation time of the ultrasonic wave until the other ultrasonic transducer receives the ultrasonic signal, and a flow rate that determines the flow rate of air that fills the space between the ultrasonic transducers by calculation from the propagation time It comprises a calculation unit and a human body detection unit that determines the presence or absence of a person based on the flow rate obtained by the flow rate calculation unit, and human body detection can be performed without any limitation on the detection range.

  In the second invention, particularly in the first invention, the human body detection detects the presence of a person different from the normal time by comparing the flow rate pattern of the flow rate calculated by the flow rate calculation unit with the normal flow rate pattern. Thus, it is possible to provide a human body detection device that can determine not only the presence or absence of a person but also whether or not the movement is abnormal by comparing a fluctuation pattern caused by the movement of the person with a normal pattern.

  The third invention is characterized in that, in the first or second invention, the flow path has a cylindrical shape with both ends open.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of an ultrasonic flowmeter according to the first embodiment of the present invention.

  As shown in FIG. 1, the human body detection device drives the ultrasonic vibrators 1 and 2 and the ultrasonic vibrator 2 installed at both ends of a measurement flow path 3 configured so that both ends are open and air flows. Drive circuit 10 for controlling, a control unit 5 for outputting a start signal to the drive circuit 10, a propagation time measuring unit 4 for measuring the propagation time of the ultrasonic wave, and the ultrasonic transducers 1 and 2 by calculation from the propagation time. The flow rate calculation unit 7 for obtaining the flow rate of air satisfying the condition, the ultrasonic transducer 1 that receives the ultrasonic waves transmitted from the ultrasonic transducer 2, and the flow rate fluctuation amount calculated by the flow rate calculation unit 7 determine the presence or absence of a human body. It comprises a human body detection unit 8 for determining, and an alarm device 9 for issuing a warning especially when a human body is detected.

  Moreover, the detection flow rate setting part 11 which can set a detection flow rate range for every installed environment is provided, and the sensitivity of the human body detection according to the area of a room etc. can be adjusted.

  The operation and action of the human body detection apparatus configured as described above will be described below.

  First, the flow rate of air that satisfies the space between the ultrasonic transducers 1 and 2 calculated by the flow rate calculation unit 7 based on the propagation time of the ultrasonic waves between the ultrasonic transducers 1 and 2 measured by the propagation time measurement unit 4. Ask for.

  Here, the human body detection unit 8 notifies the presence of a person by the alarm device 9 when a flow rate fluctuation equal to or higher than the flow rate set by the detection flow rate setting unit 11 occurs.

  The flow rate calculated by the flow rate calculation unit 7 is generated in the air flow due to the movement of the person, and the human body detection unit 8 detects the presence or absence of a person based on the magnitude of the flow rate change. , It depends on the size of the room, the speed of movement of people, and the range of movement.

  Therefore, in the present embodiment, the detection flow rate setting unit 11 can appropriately set the magnitude of the flow rate fluctuation for detecting a person, so that the optimum sensitivity can be set for the size of the room and the installation location. It is said.

  Therefore, by installing the installation place not only in a room but also in a car or a safe as a sealed space, it can also be used as an alarm device for preventing vandalism and theft of valuables.

(Embodiment 2)
FIG. 2 shows a configuration diagram of an ultrasonic flowmeter according to the second embodiment of the present invention, and FIG. 3 is a graph showing two flow patterns showing different fluctuations due to human movement. In addition, the thing of the same code | symbol as Embodiment 1 has the same structure, and abbreviate | omits description.

  2, the human body detection unit 12 determines the presence or absence of a person based on the flow rate fluctuation pattern detected by the flow rate calculation unit 7. FIG. 3 shows the flow rate fluctuation pattern (normal pattern) of air generated by a normal life pattern. ) And an example of a flow rate fluctuation pattern (abnormal pattern) when there is a person who performs suspicious behavior. In the human body detection unit 12, the flow rate fluctuation pattern obtained by the flow rate calculation unit 7 is shown in FIG. It is determined whether or not it matches the normal pattern shown in FIG. 4B. If it does not match, it is determined that there is a person who performs suspicious behavior, and the alarm device 9 issues an alarm.

  This makes it possible to say that when there is an area where a person is not normally accessible in one room, a warning is given because the flow rate fluctuation pattern is different from that of a person when the person approaches this area.

  Therefore, according to the present embodiment, it is possible to provide a human body detection device that can determine not only the presence / absence of a person but also whether it is abnormal or not by comparing a fluctuation pattern caused by a person's movement with a normal pattern.

  As described above, in the present embodiment, by detecting minute vibrations, a warning can be transmitted to picking or forcibly opening the door to prevent entry.

  As described above, since the human body detection device using ultrasonic waves according to the present invention detects changes in the air flow, it is a highly sensitive ultrasonic intruder detection crime prevention device with no limitation in detection range or installation direction. A sensor can be realized.

1, 2 Ultrasonic transducer 3 Measurement channel (channel)
4 Propagation time measurement unit 7 Flow rate calculation unit 8, 12 Human body detection unit 9 Alarm device 11 Detection flow rate setting unit

Claims (3)

A pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals arranged at predetermined intervals on the flow path;
A propagation time measuring unit that measures the propagation time of the ultrasonic wave transmitted from one of the ultrasonic transducers until the other ultrasonic transducer receives the ultrasonic signal propagated through the air in the flow path;
A flow rate calculation unit for obtaining a flow rate of air that fills between the ultrasonic transducers by calculation from the propagation time;
A human body detection unit for determining the presence or absence of a person based on the flow rate obtained by the flow rate calculation unit;
A human body detection device. 2. The human body according to claim 1, wherein the human body detection detects the presence of a person different from the normal state by comparing the flow rate pattern of the flow rate calculated by the flow rate calculation unit with a normal flow rate pattern. Detection device. The human body detection device according to claim 1, wherein the flow path has a cylindrical shape with both ends open.

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