JPH08166449A - Ultrasonic doppler type detector - Google Patents

Abstract

PURPOSE: To obtain an ultrasonic Doppler type detector which can be installed even in a limited space and can obtain distance information easily by detecting the presence or the movement of a human body or an object surely. CONSTITUTION: A transmitter 3 comprises an ultrasonic oscillator, e.g. a piezoelectric element, and receives the output from an oscillator 1 through an amplifier 2. An ultrasonic wave having frequency f0 equal to the output frequency from the oscillator 1 is transmitted from the transmitter 3. The ultrasonic wave reflected from an object to be detected, i.e., a mobile, is received by a receiver 4. A receiving signal f' is amplified by an amplifier 5 and mixed with the output from the oscillator 1 by a mixer 6 which produces a beat signal of the transmission frequency and the receiving frequency. The output beat signal (Doppler signal Δf)is detected by a detector 7 and amplified by an amplifier 8 and a load 10 is driven when an input from an output circuit 9 higher than a predetermined threshold value is present.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic Doppler type detecting device, and more particularly to a technique using the Doppler type such as how to grasp distance information and application to a load.

[0002]

2. Description of the Related Art Conventionally, generally used ultrasonic wave detectors using the Doppler method mainly detect moving objects. For example, intruders of thieves who enter a room, a car, a show window, or the like. Many products have been developed for warning. The ultrasonic detection device using the Doppler method is not affected by the environment in which it is installed,
Even in a narrow place, and in extreme cases, even if there is an object in front of the installed object, it will not detect this,
It constantly seeks to detect the presence of moving objects.

On the other hand, the ultrasonic pulse reflection type detection device can grasp the distance information to the object by always detecting the presence or absence of the object within the predetermined detection area. Therefore, if a stationary object is always arranged in the detection area, it remains in the detection state, and therefore the construction condition of the detection device becomes necessary.

[0004]

The Doppler method and the pulse reflection method in the ultrasonic detecting device can be divided into different functions and uses by detecting the movement and presence of the object to be detected. However, at present, there is no simple method to effectively utilize the characteristics of each. For example, when installing in a narrow space and trying to grasp the presence of a human body, an object, or a sense of distance, the pulse reflection method cannot be used because an obstacle such as a wall is mistakenly detected. There is the inconvenience of not being able to take it.

There is a method called the pulse Doppler method, but in principle, the pulse reflection method is adopted, and the Doppler method and the pulse reflection method are compatible by extracting the Doppler in the continuous wave portion in the pulse. However, the detection device adopting such a method is not practical because the internal circuit becomes complicated. The Doppler type ultrasonic detection device according to the present invention can be installed in a limited narrow space in view of the above problems.
Its purpose is not only to detect the presence or movement of the human body or object with certainty, but also to easily grasp the sense of distance.

[0006]

An ultrasonic Doppler type detecting device according to the present invention is for achieving the above object, and the invention of claim 1 is a wave transmitting device for continuously transmitting an ultrasonic wave. A moving object in a predetermined spatial region, and a wave receiving means for performing processing for detecting the presence of the moving object by a reflected wave from the moving object to be the detected object in a predetermined spatial region, The present invention is characterized in that it continuously receives reflected waves from the device and drives the load by taking in the distance information of the moving object by the amplitude of the signal of the receiving system including the frequency shift.

The invention of claim 2 is characterized in that, in the invention of claim 1, there is provided means for varying a light quantity of a lamp as a light source as a load based on distance information of a moving object. The invention of claim 3 is characterized in that, in the invention of claim 1, there is provided means for varying the volume of the sound source as a load based on the distance information of the moving object.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a means for sampling the frequency component of the Doppler signal extracted by the moving object and varying the load state is also provided. According to the invention of claim 5, in the invention of claim 1 or claim 2, as the distance information of the moving object, a strong light amount is emitted to a far object to be detected, and a weak light amount is emitted to a near object. It is characterized by having a control means for performing such a control operation.

According to a sixth aspect of the present invention, the wave transmitting means for continuously transmitting ultrasonic waves and the presence of the moving object are detected by the reflected wave from the moving object to be the object to be detected within a predetermined spatial region. In an ultrasonic detection device having a wave receiving means for performing a detecting process, a determination means for sampling the amplitude level of a Doppler signal extracted by a moving object and averaging the amplitude level to extract distance information to the moving object. It is characterized by having.

According to a seventh aspect of the present invention, the presence of the moving object is detected by the wave sending means for continuously sending out the ultrasonic wave and the reflected wave from the moving object to be the object to be detected within a predetermined spatial region. An ultrasonic detecting device including a wave receiving unit that performs a process of detecting, characterized in that it has a determining unit that receives a reflected wave from a moving object and determines the output amplitude of the wave receiving and amplifying unit at the first stage. It is what

[0011]

Next, the operation of the ultrasonic Doppler type detection device according to the present invention will be described. The wave transmitter is composed of an ultrasonic transducer such as a piezoelectric element, and the output of the oscillator is input to the wave transmitter via an amplifier. Then, an ultrasonic wave having a frequency equal to the output frequency of the oscillator is emitted from the transmitter. The ultrasonic waves emitted by the wave transmitter and reflected by the moving object to be the object to be detected are received by the wave receiver.
After this received signal is amplified by the amplifier, it is mixed with the output of the oscillator by the mixer, and a beat signal of the transmission frequency and the reception frequency is obtained at the output of the mixer. The output (Doppler signal) by the beat signal is detected by the wave detector, then amplified by the amplifier, and the load is driven by the output circuit if there is an input equal to or more than a predetermined threshold value.

[0012]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram of one embodiment of an ultrasonic Doppler type detection device according to the present invention, which uses an ultrasonic sensor utilizing the Doppler effect. In the figure, 1 is an oscillator, 2 is an amplifier, 3 is a wave transmitter, 4 is a wave receiver, 5 is an amplifier, 6 is a mixer, 7 is a detector, 8 is an amplifier, 9 is an output circuit, 10 is a load, 11 Is a determination means circuit.

Next, the operating state will be described. The ultrasonic wave emitted by the wave transmitter 3 and reflected by the moving object to be the object to be detected is received by the wave receiver 4, and the frequency that is the Doppler effect is obtained by comparing the transmission frequency with the reception frequency. When the deviation occurs, it is determined that the detected object has moved within the detection area. Transmitter 3
Is composed of an ultrasonic transducer such as a piezoelectric element. By inputting the output of the oscillator 1 to the wave transmitter 3 via the amplifier 2, an ultrasonic wave having a frequency equal to the output frequency f ₀ of the oscillator 1 is generated. It is emitted from the transmitter 3. The reception signal f'of the ultrasonic wave emitted by the wave transmitter 3 and reflected by the object to be detected is received by the wave receiver 4, and the received signal is amplified by the amplifier 5. The output signal of the mixer 6 is mixed with the output, and a beat signal having a transmission frequency f ₀ and a reception frequency f ′ is obtained. The output by the beat signal (Doppler signal Δf) is detected by the detector 7, amplified by the amplifier 8, and the load 10 is driven by the output circuit 9 if there is an input equal to or more than a predetermined threshold value. .

By the way, the Doppler signal Δf detected by the detector 7 is used to detect a distant object as shown in FIG. 2A when an object of the same speed and size approaches the detecting device. When the object is moved, the amplitude becomes small, and when the object comes close to the object due to the movement as shown in FIG. 2B, the amplitude of the reflection level becomes large, and the Doppler signal generated therefor is generated. The amplitude of Δf becomes large.

This Doppler signal Δf is used as a judging means circuit 1
2 and sets the threshold value to, for example, four steps as shown in FIGS. 2A and 2B, samples the peak value of the Doppler signal Δf that exceeds each threshold value, and By performing the averaging process, approximate distance information can be extracted. The load 10 can be changed by inputting this output to the output circuit 9.

Although the Doppler signal Δf detected by the detector 7 is used in the above operation, the signal from the amplifier 8 is used when the amplification degree of the amplifier 8 is relatively low. Even if the same result is obtained. FIG. 3 is a block diagram of another embodiment of the ultrasonic detecting apparatus according to the present invention. In this figure, the portions corresponding to those in FIG. The operation similar to that described with reference to FIG. 1 is performed. However, the method of obtaining the amplitude level as the distance information is not the Doppler signal Δf as in the case of the embodiment described with reference to FIG. 1, but the reception signal f ′ of the reflected wave of the ultrasonic wave. Then, the received signal f ′ itself subjected to the frequency shift is amplified by the amplifier 5, but if it is extracted from a place with a low amplification degree, the reflection from the far detection object has a low amplitude as shown in FIG. 4 (A). In addition, as shown in FIG. 4 (B), the reflection from the object to be detected is a large amplitude level. By inputting this signal to the output circuit 9 via the judging means circuit 12, the load 10 can be changed as in the case of the first embodiment.

In the embodiment shown in FIGS. 1 and 2, when a lamp is used for the load 10 as a light source, for example, the distance information gives a strong light quantity to a far detection object and is close to it. By performing a control operation that emits a weak light amount to the object to be detected, it is possible to make a useful application in actual use of the lamp. For example, when a user approaches from a distant place in a garden or a parking lot at home, if the light source is constant, the brightness is attenuated to make the feet darker, and the brightness near the light source causes glare. can get. In this way, a well-balanced control operation is performed, but when the threshold value exceeds the level 4 as shown in FIGS. 4A and 4B, the output of the output circuit 9 is lowered,
Further, when the threshold value exceeds the level 1, the output of the output circuit 9 may be controlled to be increased.

Considering the case where a sound source such as a speaker, a buzzer, or a horn is used as the load 10, when a detected object moves near the sound source as distance information of a moving object, a loud sound is heard at the ear. There is no need. FIG. 5 is a block diagram of still another embodiment of the ultrasonic detecting apparatus according to the present invention, in which FIG.
The parts corresponding to those in FIG. 3 are denoted by the same reference numerals as those in FIGS. 1 and 3, and the same operation as that described in FIGS. 1 and 3 is performed. In this embodiment, the load 10 is controlled by considering not only the distance information described in FIG. 1 but also the value of the Doppler signal Δf itself.
The frequency of the Doppler signal Δf obtained by the detection by the detector 7 and determined by the frequency determination means 13 is 0 Hz if the object to be detected does not exist, but the faster the moving speed of the object to be detected is. The frequency of the Doppler signal Δf becomes high.

The frequency of the Doppler signal Δf is Δ
It will be represented by f = 2Vf ₀ / C. Here, V is the moving speed of the detected object, f ₀ is the oscillation frequency, and C is the speed of sound. For the frequency of the Doppler signal Δf, for example (0 to Δf
₁ ), (Δf _{1 to} Δf ₂ ), (Δf ₂ or more) are provided in advance, and the frequency determination means 13 recognizes the threshold values to control the output of the output circuit 9. A new control operation of the load 10 is possible. For example, at night, there is a slow motion for a certain period of time by discriminating the movement of the resident in the garden of the house and the careful movement of the thief's foot, foot, and sneaky wind.
It can be applied such as sounding a big alarm sound when a person approaches.

[0020]

The ultrasonic Doppler type detection apparatus according to the present invention is constructed as described above, and the inventions of the respective claims are simple in that only a simple block is added in terms of circuit. It is possible to obtain the distance information and to control various new loads. The invention of each claim has the following effects.

According to the first aspect of the present invention, peak values of Doppler signals that exceed the respective set threshold values are sampled and averaged to extract approximate distance information and output this output. The load can be changed by inputting to the circuit. According to the second aspect of the present invention, a lamp is used as a light source for the load, and a strong light amount is emitted to a far detection target object as a distance information of a moving object, and a weak light amount is emitted to a near detection target object. A control action can be performed.

According to a third aspect of the present invention, a sound source such as a speaker, a buzzer, or a horn is used as a load, and when the detected object moves near the sound source as distance information of the moving object,
You don't have to listen to loud sounds at your ears. According to the invention of claim 4, it is possible to efficiently perform a function such as a change in the light quantity of the lamp as a load and a change in the volume of the sound source.

According to the invention of claim 5, as a distance information to the moving object, a control operation is surely performed such that a strong light quantity is emitted to a far detection object and a weak light quantity is emitted to a near detection object. It can be carried out. According to the invention of claim 6, it is possible to know the approximate distance information itself to the moving object.

According to the invention of claim 7, like the invention of claim 6, it is possible to know the approximate distance information itself to the moving object.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an ultrasonic Doppler type detection device according to the present invention.

FIG. 2 (A) shows the amplitude when a Doppler signal is generated by the movement of a distant detected object, and (B) shows the amplitude when the detected object becomes closer due to the movement.
It is a graph figure which showed the amplitude of the reflection level of a Doppler signal.

FIG. 3 is a block diagram showing another embodiment of the ultrasonic Doppler type detection device according to the present invention.

4A and 4B are graphs showing amplitude when the threshold exceeds the highest level, and FIG. 4B shows amplitude when the threshold exceeds the minimum level. is there.

FIG. 5 is a block diagram showing still another embodiment of the ultrasonic Doppler type detection device according to the present invention.

[Explanation of symbols]

 1 Oscillator 2, 5, 8 Amplifier 3 Transmitter 4 Receiver 6 Mixer 7 Detector 9 Output Circuit 10 Load 11 Judgment Circuit

Claims (7)

[Claims] 1. A wave transmitting means for continuously transmitting an ultrasonic wave,
In an ultrasonic detection device equipped with a wave receiving unit that performs processing for detecting the presence of a moving object by a reflected wave from the moving object that is to be the detected object within a predetermined spatial area, a continuous wave from the moving object Receive the reflected waves,
An ultrasonic Doppler type detection device characterized in that the load is also driven by taking in the distance information of a moving object by the amplitude of the receiving system signal including the frequency shift. 2. The ultrasonic Doppler type detection device according to claim 1, further comprising means for varying a light quantity of a lamp serving as a light source as a load based on distance information of a moving object. 3. The ultrasonic Doppler type detection device according to claim 1, further comprising means for varying the volume of the sound source as a load based on the distance information of the moving object. 4. The ultrasonic Doppler type detection device according to claim 1, further comprising means for sampling a frequency component of a Doppler signal extracted by a moving object and varying a load state. 5. A control means for performing a control operation for emitting a strong light amount to a far detection object and a weak light amount to a near detection object as distance information of a moving object. The ultrasonic Doppler type detection device according to claim 1 or 2, characterized in that. 6. A wave transmitting means for continuously transmitting ultrasonic waves,
Extracted by a moving object in an ultrasonic detection device equipped with a wave receiving means that performs processing for detecting the presence of the moving object by a reflected wave from the moving object to be the detected object in a predetermined spatial area An ultrasonic Doppler type detection device, comprising: a determination unit for sampling the amplitude level of a Doppler signal and averaging the amplitude level to extract distance information to a moving object. 7. A wave transmitting means for continuously transmitting ultrasonic waves,
In an ultrasonic detection device equipped with a wave receiving unit that performs processing for detecting the presence of a moving object by a reflected wave from the moving object that is to be the detected object within a predetermined space area, reflection from the moving object An ultrasonic Doppler type detection device having a determination unit that receives a wave and determines an output amplitude of a first-stage reception amplification unit.