JPH0443987A - Human body detecting device - Google Patents

Abstract

PURPOSE:To detect even a human body which is stationary by performing presence detection by a 1st human body detection part until the human body is detected, and performing the presence detection by a 2nd human body detection part once the human body is detected. CONSTITUTION:When the human body enters a monitor area, the human body is detected from the presence of a moving body or heat rays radiated by the human body. Then, a wave transmission system control circuit 12 controls a wave transmitting circuit 2 and a switching input circuit 13 with the current control output of a decision circuit 9 to send ultrasonic wave pulses from a transmitter 3 and also switches a reception-side signal processing system to a presence detection system signal processing system. Consequently, even if the human body becomes stationary after being present in the monitor area once, the human body can be detected continuously.

Description

[Detailed description of the invention]

E. Industrial Application Field 1 The present invention is directed to a human body detection device that detects a human body using ultrasonic waves. [Conventional technique fI] A human body detection device that detects a human body using ultrasonic waves is used as a human body detection sensor for an automatic door.For example, a human body detection device used as a human body detection sensor for an automatic door is A continuous frequency ultrasonic wave is transmitted, the reflected wave from a moving object, that is, a human body, existing within the monitoring area is received, and the frequency shift component included in the received signal is detected to identify the human body. Some systems employ a WI Doppler detection method to determine the presence or absence of The configuration of this type of human body detection device is shown in FIG. In this human body detection device, a wave transmitting circuit 2 drives a wave transmitter 3 consisting of an ultrasonic vibrator based on a signal oscillated by an oscillator 1 to transmit ultrasonic waves of a predetermined frequency to a monitoring area. A reflected wave reflected by an object existing in the area is received by a receiver 4 consisting of an ultrasonic transducer, and the amplified output of the received wave output by an amplifier 5 is mixed with a transmitted signal by a mixer 6 and received. A frequency shift component, which is a Doppler component included in the output, is extracted, and the output of this mixer 6 is detected by a detection circuit 7. Based on the amplified output of this detection output by an amplifier 8, a determination circuit 9 determines whether a moving object is detected in the monitoring area. The determination circuit 9 outputs eight detection outputs when a human body is detected. By the way, the human body detection device shown in Fig. 4 is a composite type that incorporates a so-called hot-ray type human body detection unit that detects the presence or absence of a human body by detecting heat rays emitted from a human body existing within the monitoring area. , a hot ray type human body detection system using a non-electronic element 10 that detects a hot ray, an amplifier 11 that amplifies its output, and a determination circuit 9 that determines whether or not a human body is present in the monitoring area based on the output of the amplifier 11. This constitutes the detection section. [Problem to be Solved by the Invention 1] However, the above-mentioned Doppler type human body detection device has a drawback in that even if a human body exists within the monitoring area, it cannot be detected if the human body is stationary. In addition,
As shown in FIG. 4, even a composite type human body detection device including a hot wire type human body detection unit has the same drawback because the pyroelectric element 10 can only detect a moving heat source. The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a human body detection device that can detect even a stationary human body within a detection area. [Means for Solving the Problems] In order to achieve the above object, the present invention provides a first wave transmitting means for transmitting continuous ultrasonic waves of a predetermined frequency to a monitoring area, and a first wave transmitting means. a first wave receiving means for receiving reflected waves from an object existing in the monitoring area of the ultrasonic waves transmitted from the ultrasonic waves;
and a first signal processing means for detecting the presence of a human body within the monitoring area by detecting a frequency shift component caused by the movement of the object from the output of the first wave receiving means. , a second wave transmitting means for transmitting ultrasonic pulses to the monitoring area, and receiving reflected waves from objects existing within the monitoring area of the ultrasonic pulses transmitted from the second wave transmitting means. and detecting the presence or absence of a reflected wave or the time required from the time of transmitting the ultrasonic pulse to the time of receiving the reflected wave upon receiving the output of the second wave receiving means. A second human body detection section consisting of a second signal processing means that detects the presence of a human body within the surveillance area, and a first human body detection section that is operated during normal operation so that the first human body detection section monitors the human body. A delivery method control means is provided for operating the human body detection section of the IJi 2 from the time when the human body is detected to exist in the area until the human body is no longer present in the monitoring area. In addition, in order to prevent false detection in human body detection using ultrasonic pulses, the monitoring area where human body detection is performed using the above-mentioned ultrasonic pulses is smaller than the monitoring area where human body detection is performed using continuous ultrasonic waves. It is preferable to do so.

[Effect]

As described above, the present invention combines a first human body detection section using a Doppler type and a second human body detection section using a so-called presence detection method or a distance measurement method, and until a human body is detected, the first human body detection section is integrated.
The human body detection unit detects the presence of a human body, and when a human body is detected, the second human body detection unit detects the presence of a human body, so that when a human body is detected, the human body remains stationary. The system has also been switched to a human body detection method that can detect human bodies, so that even human bodies that are stationary within the detection area can be detected. [Example 11 1st v! An embodiment of the present invention is shown in Fig. 1. This embodiment is basically the same as the one in Fig. 4, and is an ultrasonic human body detection system that detects the frequency of a moving object existing in the monitoring area. This is a composite human body detection device that uses a Doppler type that detects the presence or absence of a human body by detecting a deviation component, and also includes a heat-ray type human body detection section that detects the human body by detecting heat rays emitted from the human body. be. However, in the case of this embodiment, once a human body is detected within the monitoring area, the ultrasonic human body detection method is changed from a Doppler method to a presence detection method or a distance measurement method. . Here, the presence detection method is a method of transmitting ultrasonic pulses, receiving reflected waves from objects within the monitoring area, and detecting the presence of objects from the presence or absence of received wave output from the reflected waves. The distance method transmits ultrasonic pulses, receives reflected waves from objects within the monitoring area, and calculates the distance to the object based on the time required from the time the ultrasonic pulse is sent to the time the reflected waves are received. This method detects the presence of an object within the monitoring area. In this embodiment, once a human body is detected within the monitoring area, the ultrasonic human body detection method is changed to the presence detection method. The transmitting circuit 2 of this embodiment has a function of transmitting continuous ultrasonic waves from the transmitter 3 for detecting a human body using the Doppler one-way method, and a function of transmitting continuous ultrasonic waves from the transmitter 3 for detecting a human body using the presence detection method. It is equipped with a function to transmit ultrasonic pulses, and this transmission method switching control is performed by a wave transmission method control circuit 12. This wave transmission method control circuit 12 In the second wave transmitting circuit 2, which performs the above control in response to the control output output from the determination circuit 9 when detection is detected, the wave transmitter circuit 2 normally operates according to the output shown in FIG. Drive 3. Then, when a human body is detected,
Based on the control from the wave transmission system control circuit 12, the oscillator 1
The tone burst signal shown in (c) of the same figure is created by passing the output from the transmitter 3 through the internal transmitting date (the open/closed state of the date is shown in (b) of the same figure). By driving the transmitter 3, ultrasonic pulses are transmitted from the transmitter 3. On the other hand, on the receiving side, it is selected whether to input the received wave output of the receiver 4 to the corresponding signal processing system depending on whether the ultrasonic wave is a continuous wave or a pulse wave after the receiver 4. A switching input circuit 13 is provided, and the operation of this switching input circuit 13 is controlled by a wave transmission system control circuit 12 so that the received wave output is input to a signal processing system according to the type of ultrasound. A Doppler signal processing system that detects a human body using continuous ultrasonic waves is composed of an amplifier 5, a mixer 6, a detection circuit 7, an amplifier 8, and a judgment circuit 9, as in the case shown in Fig. 14. be. In addition, the signal processing system of the presence detection method that detects a human body using ultrasonic pulses includes an amplifier 14 that amplifies the received signal, a detection circuit 15 that detects the amplified output, and a determination circuit that is also used as the Doppler method described above. The determination circuit 9 determines whether or not a human body exists within the monitoring area, depending on whether a received wave output by a reflected wave is obtained from the detection circuit 14. Now, if a human body enters the monitoring area, it will be detected by the presence of a moving object or the heat rays emitted by the human body. Then, the wave transmission method control circuit 12 controls the wave transmission circuit 2 and the switching input circuit 13 using the control output outputted from the determination circuit 9 at this time to cause the transmitter 3 to transmit ultrasonic pulses and to receive the ultrasonic pulses. Switch the side signal processing system to a presence detection type signal processing system. For this reason, once the human body is within the monitoring area, even if the human body remains stationary,
It becomes possible to continuously detect the human body. When this human body detection device is used as an automatic door sensor, it can continuously detect a stationary human body, so if a person is stationary near the automatic door, the automatic door will close, and the person will *It is possible to solve the problem of being caught. Thereafter, human body detection using the above-mentioned presence detection method is performed until no human body exists in the monitoring area, and when no human body exists, the system switches to Doppler type human body detection. Furthermore, even when switching to the presence detection method, human body detection using heat rays still functions effectively. [Embodiment 21 Figure 3 shows another embodiment of the present invention. This embodiment has exactly the same configuration as embodiment #1, and in the case of this embodiment, the presence detection method is used to detect a human body. When detecting a human body, the monitoring area of the dead body is made smaller than when detecting a human body using the Doppler single method, and for this reason, the signal amplification factor of the signal processing system of the presence detection method is set to be smaller than that of the Doppler single method. It is smaller than the amplification factor of the signal of the signal processing system. This can be achieved by making the amplification factor of the amplifier 14 in FIG. 1 smaller than the amplification factor of the amplifier 5. In this way, # As shown in Figure 13, the surveillance area entrance indicated by diagonal lines in the figure can be made smaller than the surveillance area A in the case of a single Doppler system, and can be used to detect stationary objects other than a human body (for example, a plant placed next to an automatic door). ) can be prevented from being detected. Figure 3 shows the case where the human body detection device A is installed above the automatic door. By the way, in the case of Figure 1, in order to simplify the circuit configuration, each circuit However, the key point is to combine the first human body detection section using a Doppler type and the second human body detection section using a so-called presence detection method or distance measurement method, and to detect a human body. The configuration is limited to the configuration of this embodiment as long as the first human body detection section detects the presence of a human body, and once the human body is detected, the second human body detection section detects the presence of a human body. F. Effects of the Invention] As described above, the present invention combines the first human body detection unit of Doppler type and the second human body detection unit of so-called presence detection type or distance measurement type, and detects the presence of a human body. 1st until detected
The human body detection section detects the presence of a human body, and when a human body is detected, the second human body detection section detects the presence of a human body. It is possible to switch to a human body detection method that can detect a human body even when the human body is stationary, which has the advantage of being able to detect a human body that is stationary within the detection area.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the circuit configuration of one embodiment of the present invention, Fig. 2 is an operation waveform diagram of the main parts of the same as above, Fig. 3 is an explanatory diagram of human body detection operation of another embodiment, Fig. 4 1 is a block diagram showing a circuit configuration of a conventional human body detection device. 1 is an oscillator, 2 is a wave transmitting circuit, 3 is a wave transmitter, 4 is a wave receiver,
5, 8.15 is an amplifier, 6 is a mixer, 7°14 is S! 9 is a determination circuit, 12 is a wave transmission system control circuit, and 13 is a switching input circuit. Agent Patent Attorney Ishi 1) Nao Nao 6... Mito

Claims (2)

[Claims] (1) A first wave transmitting means that transmits continuous ultrasonic waves of a predetermined frequency to the monitoring area, and reflection of the ultrasonic waves transmitted from the first wave transmitting means from objects existing in the monitoring area. a first wave receiving means for receiving waves; and a first wave receiving means for detecting the presence of a human body within a monitoring area by detecting a frequency shift component generated due to movement of an object from the output of the first wave receiving means. a first human body detection section comprising a signal processing means; a second wave transmitting means for transmitting ultrasonic pulses to the monitoring area; A second wave receiving means receives a reflected wave from an object existing within the monitoring area, and upon receiving the output of the second wave receiving means, detects whether there is a reflected wave or whether there is a reflected wave from the time the sound wave pulse is transmitted. a second human body detection unit comprising a second signal processing means for detecting the presence of a human body within the monitoring area by detecting the time required until the wave is received; and a first human body detection unit in normal operation. from the time when the first human body detection unit detects that a human body exists in the monitoring area until the human body no longer exists in the monitoring area,
A human body detection device comprising: a delivery method control means for operating a second human body detection section. (2) Human body detection according to claim 1, characterized in that the monitoring area where the human body is detected using the ultrasonic pulses is smaller than the monitoring area where the human body is detected using continuous ultrasonic waves. Device.