JPS59202083A - Ultrasonic alarm apparatus - Google Patents

Abstract

PURPOSE:To obtain stable alarm output, by separately providing an electric circuit for detecting the Doppler signal from a moving body to be detected moving so as to be separated from an alarm apparatus over a predetermined distance and an electric circuit for detecting the Doppler signal from a moving body not to be detected moving in close relation to the alarm apparatus. CONSTITUTION:An ultrasonic wave is transmitted into a warning area through a sensor 20 and reflected wave containing a Doppler signal is inputted to a detector circuit 50 through a sensor 30 and a received wave amplifying circuit 40. The detected output is inputted to electric circuits 60, 70 and the outputs thereof are inputted to an AND circuit through rectifier circuits 80, 90. In this case, the signal passing the circuit 90 is inputted to the circuit 110 through a level reversal circuit 100 and an alarm output apparatus 20 is connected to the circuit 110. The circuit 60 has characteristics sufficient for detecting an object to be detected moving at a position separated from the alarm apparatus over a predetermined distance and the circuit 70 is insufficient for detecting the object to be detected but can detect an object not to be detected moving in close relation to the alarm apparatus. By this method, erroneous detection can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic alarm device that detects a Doppler signal from a moving object and obtains an alarm output.

As an ultrasonic alarm device, there is a device δ that uses an ultrasonic sensor to detect the presence of a moving object and obtains an alarm output. That is, the ultrasonic sensor is configured to detect the movement of a person who has entered the warning area using the Doppler effect of the ultrasonic waves radiated into the area. Such an ultrasonic warning device is composed of a wave transmitting section and a wave receiving section, and the wave transmitting section sends out ultrasonic waves of a constant frequency into a warning area via a wave transmitting sensor.

The reflected wave reflected within the warning area is detected by the receiving circuit via the receiving sensor, but if there is no moving object within the warning area, this reflected wave does not contain a Doppler signal. The receiving circuit does not generate a detection signal. However, if a moving object enters the warning area, the reflected wave contains (2-PLA signal), so the receiving circuit can detect it. For extraction, electric circuits such as bandpass filters are provided in the transmitter 1 to the receiver.

The transmitted γf wave signal hits a moving object and becomes a reflected wave.''↓1
When the frequency changes due to the Tomplar effect,
By providing an electric circuit that passes only this variable frequency range, it is possible to detect a Doppler signal generated when a moving object enters the warning area.

Detection signal 1- detected through the electric circuit in this way
15 is converted to a predetermined DC level via a rectifier circuit,
When this value exceeds a predetermined value, it is determined that a moving object to be detected has entered the warning area, and the alarm output circuit is driven to generate an alarm output.

In this case, the moving object to be detected is only a moving object that is located a predetermined distance away from the alarm device and for which the output of the aforementioned electric circuit is less than or equal to a predetermined value. In other words, this is to prevent a non-detection moving object such as an insect from being detected if it enters the warning area when the person 111f is assumed to be a moving object to be detected. Conventionally, in order to detect only the moving object to be detected, the characteristic G of an electric circuit such as a bandpass filter is set to a predetermined value depending on the moving object to be detected.

That is, if the characteristic G is made very large, even extremely small moving objects can be detected, and conversely, if the characteristic G is made small, only large moving objects can be detected.

Therefore, the moving object to be detected can be selected by adjusting the characteristic G of the electric circuit such as the bandpass filter as necessary. However, simply identifying the moving object to be detected by changing only the characteristic G of the electric circuit in this way does not prevent the alarm device from malfunctioning.

In other words, the ultrasonic sensor of the alarm device is generally installed in the ceiling or the like and is configured to receive the reflected waves between it and the floor. Distinguishing between a moving object to be detected and a moving object not to be detected can be made only by adjusting the characteristics of the electric circuit described above, but for non-detecting objects that move very close to the ultrasonic sensor, it is necessary to divide this by υ1. is difficult.

In other words, when a moving object that is not to be detected, such as an insect, moves near the ultrasonic sensor, the Tonperr signal generated by this becomes an extremely large value, and the dual reception circuit treats this as the moving object that is to be detected. rll and generates an alarm output.

Therefore, when trying to operate the ultrasonic alarm device stably without malfunction, it is necessary to place the ultrasonic alarm device close to the
It is necessary to take measures to prevent alarm output from being generated in response to Doppler signals generated by non-detectable moving objects such as moving insects.

This invention has been made in order to eliminate the drawbacks mentioned above, and its purpose is to provide stable operation that does not generate an alarm output due to Doppler signals generated by undetected moving objects near the alarm device. An object of the present invention is to provide an ultrasonic alarm device that performs.

In order to achieve the above object, the present invention provides an ultrasonic alarm device that detects a Doppler signal generated by a moving object via a detection electric circuit and issues an alarm when this detection signal reaches a desired value. a first electrical circuit having characteristics sufficient to detect a first Doppler signal from a moving object to be detected that is located a predetermined distance away from the alarm device; a second electrical circuit having characteristics insufficient to detect a Doppler signal but sufficient to detect a second Doppler signal produced by an undetected moving object moving in close proximity to the alarm device; It is characterized by being divided into two parts.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a functional block diagram of an ultrasonic alarm device ξ showing an embodiment of the present invention. The ultrasonic signal generated by the wave transmitting oscillation circuit 1o is transmitted as an ultrasonic wave into the warning area via the wave transmitting sensor 20. The reflected wave containing the Doppler signal within the warning area is input to the reception amplification circuit 4o via the reception sensor 30, amplified to a required level, and then detected by the detection circuit 5o. The output of the detection circuit 50 is input to the electric circuit 6° and the electric circuit 70, respectively, and the output thereof is input to the AND circuit 110 via the rectifier circuit 80 and the rectifier circuit 90.

Note that the signal passing through the rectifier circuit 90 is passed through the level inversion circuit 10.
After inverting the signal level through 0, the AND circuit +
10 is input. The alarm output circuit 120 is operated by the output signal of the AND circuit 110 to obtain a desired alarm output.

That is, the ultrasonic alarm device according to the present invention has an additional feature in that, unlike the conventional configuration, the detection electric circuit is divided into two parts, each of which is configured with electric circuits 60 and 70.

Note that the electric circuit 60 has characteristics sufficient to detect a Doppler signal from a moving object to be detected that is located a predetermined distance away from the alarm device;
Although it is not sufficient to detect the Doppler signal from the above-mentioned moving object to be detected, it has sufficient characteristics to detect the Doppler signal generated by the moving object to be detected that moves close to the alarm device. It is designed to.

In other words, since the electric circuit 70 is designed to have lower characteristics than the electric circuit 60, the Doppler signal from the moving object to be detected may not be detected, or the Doppler signal may not be detected from the moving object to be detected, or from a moving object to be detected which is moving close to the alarm device. The Doppler signal is so strong that it can be detected.

The output of the electric circuit 60 obtained via the rectifier circuit 80 becomes high level when a Doppler signal is detected, and becomes low level when not detected.

Similarly, the output of the electric circuit 70 obtained via the rectifier circuit 80 also becomes a high level when a Doppler signal is detected, and becomes a low level when a Doppler signal is not detected.

FIG. 2 is a diagram that reduces the frequency characteristics of the electric circuits 60 and 70. Curve A shown as a solid line represents the characteristic curve of the electric circuit 60, and curve B shown as a dotted line represents the characteristic curve of the atmospheric filter 70. Curves A and B have different characteristics G, but the frequencies f are almost the same, and the detection frequency j of the I-Tupler signal. shows its greatest characteristics.

Next, the operation of the circuit shown in FIG. 1 will be explained.

When only a moving object to be detected enters the warning area, an electric circuit 60 such as a bandpass filter detects the Doppler signal from the moving object to be detected, and maintains the output of the rectifier circuit 80 at the /\I level.

- Since the electric power circuit 70 has low characteristics as described above, it cannot detect the Doppler signal from the moving object to be detected, so the output of the rectifier circuit 90 becomes low level. Therefore, the signal input to the AND circuit 110 via the level inverting circuit 100 becomes /\I level.

In this way, when the input signals of the AND circuit 110 are both at high level, the output thereof will also be at high level, and if the alarm output circuit 120 is configured to operate in response to the high level, the alarm output will be Occur. Such an operation is a normal detection operation.

On the other hand, if there is a moving object that is not to be detected, such as a moving object that is moving in close proximity to the alarm device, the Doppler signal generated from this moving object that is not to be detected has an extremely high signal level, and therefore not only the electrical circuit 60 but also the This is also detected in the electric circuit 70, and therefore the outputs of the rectifier circuit 80 and the rectifier circuit 90 both become high level.

Therefore, since one of the input signals of the AND circuit 110 is at a low level, its output is at a low level, and the alarm output circuit 120 cannot be operated, so no alarm output is generated. Therefore, it is possible to prevent the alarm device from malfunctioning due to the intrusion of a moving object that is not to be detected.

Figure 3 shows the function block diagram shown in Figure 1.
This is an example of a detailed circuit diagram. The parts surrounded by diagonal lines and having the same numbers as shown in FIG. 1 correspond to the functional blocks shown in FIG. 1, respectively. Although not shown in the figure, this circuit uses the light emission output of the LED as an alarm output.

The iL circuits 60 and 70 are configured by a combination of a low-pass filter and a high-pass filter using, for example, a differential operational amplifier, and their characteristics can be set to desired values by appropriately designing circuit constants. .

It should be noted that the circuit shown in FIG. 3 is merely an example of an embodiment, and it goes without saying that an electric circuit having a similar operation can be realized by various modifications.

As described in detail based on the following two embodiments, the present invention provides electric circuits that respond to the Doppler signal from the moving object to be detected and the Doppler signal from the moving object to be detected, respectively. This has the advantage that it is possible to realize a stable ultrasonic alarm device that does not operate against intrusion of objects.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram showing an embodiment of this invention, Fig. 2 is a diagram showing the characteristics of an electric circuit used in this invention, and Fig. 3 is an example of realizing the functional block diagram shown in Fig. 1. FIG. 60... first electric circuit, 70... second electric circuit. 80... Rectifier circuit, 8o... Rectifier circuit. 100... Level inversion circuit, 11o... AND circuit. 120...Alarm output circuit. Applicant Nippon Aleph Co., Ltd. Agent Patent attorney Kuninori Funabashi

Claims (1)

[Claims] 1. In an ultrasonic alarm device that causes a Doppler signal generated by a moving object to pass through an electric circuit and issues an alarm when this detection signal reaches a desired value, the electric circuit is connected to the alarm device. a first electrical circuit having characteristics sufficient to detect a first Tomplar signal from a moving object to be detected that is in a fixed position and moves by a predetermined distance; a second electrical circuit having insufficient characteristics, but sufficient characteristics to detect a second Doppler signal generated by a non-detectable moving object moving in close proximity to the tμ device; An ultrasonic alarm device characterized by comprising: 2. The ultrasonic alarm device according to claim 1, wherein the first electric circuit and the second electric circuit are bandpass filters.