JPH0443986A - Human body detecting device - Google Patents

Abstract

PURPOSE:To know that a microwave is neither sent nor received by providing an abnormality detecting means wherein a signal processing means compares the output of an amplifier with a threshold value indicating abnormality. CONSTITUTION:The fault of a microwave element 1 is detected from the output v2 of the amplifier 7a in the 1st stage of an amplification part 7. For the purpose, this device is provided with the abnormality detecting circuit 10 which compares the output v2 with the threshold value Vth indicating the abnormality of the microwave element 1, etc., and an output circuit 11 which receives the output of the abnormality detecting circuit 10 and displays the abnormality by an abnormality display circuit 12. Namely, when the output v2 of the amplifier drops below the threshold value Vth, the output V3 of the comparator 10 of the abnormality detection part falls to a low level and the output circuit 11 receives the output obtained by inverting the output of the comparator 10a by a transistor Q1 and displays the abnormality by the abnormality display circuit 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a human body detection device including a micro-cross type human body detection section that detects a human body using at least microwaves.

E. Prior Art l A human body detection device that detects a human body using microwaves is used, for example, as a security sensor to detect an intruder into a monitoring area, and transmits microwaves of a predetermined frequency to the monitoring area. The reflected signal from a moving object (in other words, a human body) existing in the monitoring area of the transmitted microwave is received, and the w4wL number deviation generated due to the movement of the object included in the received output is detected and monitored. There are devices that detect the presence of a human body within an area.

Furthermore, in order to prevent false alarms, some of this type of human body detection device is a composite type equipped with a heat ray type human body detection section that detects the presence of a human body by detecting heat rays emitted by the human body.

Problem 1 to be solved by invention E: However, in conventional human body detection devices using microwaves of this type, the microwave elements that transmit and receive microwaves break down, making it impossible to transmit and receive microwaves. In some cases, there is no way to recognize this (there is a problem that can lead to false alarms).

In addition, even in the case of the above-mentioned composite human body detection device,
Since this human body detection device generates a human body detection output when both types of human body detection sections obtain outputs, false alarms also occur.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a human body detection device that can detect when microwave transmission and reception are no longer possible.

[Means for Solving the Problems Pi1 In order to achieve the above object, the present invention provides a threshold value indicating an abnormality of the transmitting/receiving means by converting the output of the intensifier included in the signal processing means that outputs a DC component according to the received output. and abnormality detection means for detecting an abnormality in the transmitting/receiving means.

Further, there is a transmitting means for transmitting microwaves to a monitoring area, a receiving means for receiving a reflected signal of the transmitted microwaves from a moving object existing in the monitoring area, and a receiving output of the receiving means that detects a signal as the object moves. The signal processing means detects the presence of a human body within the monitoring area by detecting the frequency shift component that occurs, and the signal processing means outputs a DC component according to the received output. a micro-cross-type human body detection unit that detects an abnormality in the transmitting/receiving means by comparing it with a threshold value shown in the figure; In order to prevent false alarms in the case of a composite human body detection lIW, which includes a determination unit that determines that a human body is present when both of the human body detection units obtain detection outputs, it is necessary to When the abnormality detection output is output, the determination unit may determine the presence of a human body in accordance with the detection output of the hot wire type human body detection unit.

[Operation j] The present invention focuses on the fact that when the microphone o@ stops transmitting and receiving, the output of the amplifier that outputs the DC component according to the received output of the signal processing means also decreases, and this is detected as an abnormality. By detecting with a means, it is possible to detect that microwaves are not being transmitted or received.

[Real side 1] An embodiment of the present invention is shown in FIGS. 1 and 2. FIG.

In the following description, the configuration and operation will be explained. In this embodiment, as shown in FIG.
A drive circuit 3 includes a microwave element 1 that transmits and receives al.
Drive the microphone AM of a predetermined frequency! ILIIl
Send to area. Note that the drive circuit 3 drives a diode serving as a transmitting element of the microwave element 1.

The reflected signal from a moving object (in other words, a human body) existing in the monitoring area of the transmitted microwave is transmitted to the microwave element 1.
received at Since the reflected signal received by this microwave element 1 is shifted to a frequency proportional to the moving speed due to the Doppler effect, the frequency shift component included in the received output of this microwave element 1 is detected by a sample and hold circuit. Extract with 4. That is, the sample and hold W64 samples and holds the received signal according to the output of the pulse generator 2, thereby removing the transmitted signal from the delivered signal and extracting the frequency shift component. The sample hold circuit 4
The amplified output of the output from the intensifier 5 is detected by a detection unit 1s6, and the detection circuit 8 detects the presence or absence of a human body in the monitoring area from the amplified output of the detected output by the intensifier 7.
In addition, in this human body detection device, a human body detection display is performed by the display circuit 9 when a human body is detected.

By the way, in this type of human body detection device using microwaves, the microwave element 1 normally outputs a shaped signal as shown in FIG. 2 (-). However, in the event of an abnormality such as when a failure occurs in the microwave element 1, the microphone aJli element 1
The output V is no longer generated as shown on the right in the figure. In this case, the output v2 of the first stage amplifier 7a of the amplification s7 decreases as shown in FIG. 2(b). Therefore, in this embodiment, a failure of the microwave element 1 is detected from the output v2 of the intensifier 7 at the first stage of the amplifying section 70. For this purpose, an abnormality detection circuit 10 detects a failure of the microwave element 1 by comparing the output v2 with a threshold value vth indicating an abnormality in the microwave element 1, etc. An output circuit 11 is provided to cause the display circuit 12 to display an abnormality display. That is, as shown in FIG. 2(b), when the output v2 of the intensifier falls below the threshold value Vth, the output V of the comparator 10m of the abnormality detection section 10 becomes low level, and this comparator An output circuit 11 receives an output obtained by inverting the output of 10m by a transistor Q, and causes an abnormality display circuit 12 to display an abnormality.

[5j Example 2] Fig. 3 shows another example of the present invention, and this example is a composite type human body detection device in which a heat ray type human body detection unit that detects heat rays emitted from the human body is combined. The invention is applied to a heat ray detection circuit that uses an electroless element 13 that detects heat rays emitted by a human body and a detection circuit 15 that determines the presence of a human body in a monitoring area from the amplified output of the pyroelectric element 13 output by an intensifier 14. This constitutes the human body detection section of the formula. Here, in the case of this embodiment, a determination circuit 16 is provided that performs a comprehensive determination of the presence of a human body by using both the outputs of the micro-cross type human body detection unit and the hot wire type human body detection unit, Normally, when a human body detection output is obtained from both the micro-wire type human body detection unit and the hot wire type human body detection unit, the display circuit 9 displays a human body detection display. In the case of a composite type human body detection device that displays a detection display when both signals are obtained, if the microwave element 1 or the like fails, the detection display will not be performed. When a wave failure is detected, the determination circuit 16 performs arithmetic processing to display a detection display using only the output of the hot wire type human body detection unit, thereby eliminating false alarms.

[Effect of the Invention 1] As described above, the present invention compares the output of the amplifier provided in the signal processing means that outputs a DC component according to the received output with a threshold value indicating an abnormality in the transmitting/receiving means. Since it is equipped with an abnormality detection means for detecting an abnormality, it is possible to detect an abnormality in the transmitting/receiving means from the output of the intensifier, which has the advantage of being able to know that microwaves are not being transmitted or received.

In addition to the Doppler type human body detection unit that uses microwaves, there is also a hot-wire type human body detection unit that detects the human body by detecting heat rays emitted by the human body, and both of the above human body detection units can provide detection output. In the case of a composite human body detection device that includes a determination unit that determines that a human body is present when the abnormality detection means outputs an abnormality detection output from the abnormality detection means, the determination unit If the presence of a human body is determined according to the detection output of the sensor, false alarms can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, FIG. 2 is an explanatory diagram of the same operation, and FIG. 3 is a circuit diagram of another embodiment. 1 is a microwave element, 2 is a pulse generator, 3 is a drive circuit, 4 is a sample hold circuit, 5°7 is an amplifier, 6
is a detection circuit, 8.15 is a detection circuit, 13 is a pyroelectric element, 1
0 is an abnormality detection circuit, and 16 is a determination circuit. Agent Patent Attorney Ishi 1) Choshichi

Claims (2)

[Claims] (1) A transmitting means for transmitting microwaves to a monitoring area, a receiving means for receiving a reflected signal of the transmitted microwaves from a moving object existing in the monitoring area, and a receiving output of the receiving means to determine whether the object moves as the object moves. An abnormality in the transmitting/receiving means includes a signal processing means for detecting the presence of a human body in the monitoring area by detecting frequency shift components generated by Anomaly detection means for detecting an abnormality in a transmitting/receiving means by comparing it with a threshold value indicating a human body detection device. (2) A transmitting means for transmitting microwaves to a monitoring area, a receiving means for receiving a reflected signal of the transmitted microwaves from a moving object existing in the monitoring area, and a receiving output of the receiving means to determine whether the object moves as the object moves. An abnormality in the transmitting/receiving means includes a signal processing means for detecting the presence of a human body in the monitoring area by detecting frequency shift components generated by A micro cross-type human body detection unit that detects an abnormality in the transmitting/receiving means by comparing it with a threshold value that indicates and a determination unit that determines that a human body is present when both of the human body detection units obtain detection outputs, when an abnormality detection output is output from the abnormality detection unit. A human body detection device characterized in that the determination section determines the presence of a human body according to the detection output of a hot wire type human body detection section.