JPS61270686A - Detecting device for moving body - Google Patents

Abstract

PURPOSE:To simplify a device and to improve transmission frequency removal performance by using transmit signals of two ultrasonic heads and removing transmit wave frequency components mutually. CONSTITUTION:An oscillator 1 oscillates a frequency signal in the ultrasonic wave range, ultrasonic waves are transmitted continuously to monitor spaces of two independent monitor areas from two ultrasonic heads 4 and 11, and reflected waves from a target are received by the heads 4 and 11. A differential amplifier 5 inputs the outputs of the heads 4 and 11 directly and cancel transmit frequency components by the outputs of the heads 4 and 11 which contain the transmit frequency components of the output of the oscillator 1 to extract only receive wave components. Further, the detecting means consisting of a mixer 6 and a detecting circuit 7 detects the Doppler signal generated by the reflected waves from the moving body with the received wave component from the amplifier 5 and the frequency component from the oscillator 1. Consequently, two devices need not be used and two differential amplifier need not be used either, thereby simplifying the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a transmitting/receiving integrated type moving object detection device that uses ultrasonic waves to detect a target object moving within a monitoring space and activates a switch.

[Background technology 1] Figure 3 shows a conventional integrated transmitter/receiver type moving object detection device.
This diagram shows a frequency signal in the ultrasonic range from an oscillator 1, and transmits frequency signals 1 and 2 to a transmitting amplifier 2.
After the power is amplified, it is applied to the ultrasonic head 4 via the immunity circuit 3. The ultrasonic radar 4 emits ultrasonic waves corresponding to the applied signal toward the monitoring space, and the emitted ultrasonic waves are reflected from objects in the monitoring space, reach the ultrasonic radar 4, and generate electrical signals. It outputs an output that is converted into a signal and combined with the transmitted signal. The output of this ultrasonic heater 4 includes a transmitting frequency component and a receiving frequency component, and the output of the ultrasonic heater I'4 (+'4) and the transmitting signal from the amplifier 2 are By inputting the signals with the same amplitude and the same phase into the differential amplifier 5, the transmitted frequency component is removed and only the received signal is extracted. In order to detect the panoplar m (generated by waves), the signal from the oscillator 1 and the output of the differential amplifier 5 are mixed by a mixer 6. This mixing by the mixer 16 generates a Doppler shift frequency that corresponds to the moving speed of the reflecting object. From the output of this mixer 6, the detection circuit 7
Detects the Doppler (No. 4 is detected 17, further amplified by the amplifier εj, and when there is a tumbler signal above a certain level, the switching circuit 5) is operated, and the second J2 detects the moving object. It is something.

However, using this kind of equipment' (two independent surveillance systems)
In order to obtain the a region, the entire device shown in FIG. 3 is used, or at least it is necessary to configure the circuit as shown in FIG. 4. That is, in the circuit shown in FIG. 4, the output signal of the wave transmitting amplifier 2 is applied to the other ultrasonic head 11 via the inbegence circuit 1 (>) in the same way as driving the throat 4 to the ultra-η wave. transmits ultrasonic waves 17, inputs signals from the amplifier 2 to the differential amplifier 12, and receives signals of reflected waves from the moving object to the ultrasonic head 11.
(output) is extracted by the differential amplifier 12. By adding the output of this differential amplifier 12 and the output jJ of the other differential amplifier 5, and performing step P14 similar to the device shown in FIG. This method detects a moving object in a region.However, there is a problem with the method described in [5. There has been a problem in that it is difficult to make the transmission signal input as the reference 4% signal of the differential amplifier to have the same phase and amplitude as the output of the ultrasonic head in order to remove the difference.

“Objective of the Invention 1 The present invention has been provided in view of the points mentioned in -1-
When locally monitoring a surveillance space of 2-] using two ultrasonic heads, two respective transmission signals are used to quickly remove the transmission frequency components. This is to provide a t-shift'Ih* body detection device with the purpose of simplifying the entire structure and improving the transmission frequency removal component by 41 points.

[Disclosure of the Invention 1] The above is a part of explaining embodiments of the present invention with reference to the drawings (-6) Figure 1 shows a block diagram of the present device, in which an oscillator 1 generates a frequency signal in the ultrasonic range. After oscillating and amplifying the power with the transmitting amplifier 2, the in-begence circuit 3.1
0 and is applied to the ultra-self-wave head 4.11. The ultrasonic heads 4 and 1.1 emit ultrasonic waves corresponding to the applied signals toward their respective monitoring spaces, and the emitted ultrasonic waves are reflected by objects in the monitoring space, and the reflected ultrasonic waves are reflected by objects in the monitoring space. The sound waves reach the ultrasonic nodes 4 and 11 respectively [2
The output is converted into an electrical signal and combined with transmission wave number 48. The received wave components are extracted by inputting the two outputs of the ultrasonic head 4.11 to the differential amplifier 5.

That is, the transmission frequency components contained in the two ultrasonic waves 4 and 11 are used to cancel each other out, thereby making it possible to remove the transmission frequency components. This differential amplifier 5 constitutes a transmission frequency component removing means. In addition, 2
-), the ultrasonic waves from the respective ultrasonic heads 4, 11 are input directly to the differential amplifier 5 from the nodes 4, 11.
Since they have almost the same impedance, the waveforms of the transmitted wave signals are equal to each other, that is, they have the same phase and the same amplitude, which improves the transmission frequency removal performance. By the way, this differential amplifier 5 extracts the difference in the output change of the ultrasonic head 4. However, unless they have exactly the same moving speed and reflection level, the output of the differential amplifier 5 will be obtained, and such identical movements will exist continuously. That's impossible. Furthermore, in order to detect a Doppler signal generated by reflection from a moving target object, a signal from a part of the transmitted signal and the output of the differential amplifier 5 are mixed by a mixer 6, and the A PTO H signal having a Doppler shift frequency is generated, a Doppler signal component is detected by a detection circuit 7, and this Doppler signal is further amplified by an amplifier 8, and when a Doppler signal of a certain level or higher is present, a switching circuit is activated. 9, moving objects are detected in two independent monitoring areas. Incidentally, a detection means for detecting a Doppler signal is constituted by Miki→J6 and the detection circuit 7.

FIG. 2 shows another embodiment, in which a phase shifter 13 is provided between the transmitting amplifier 2 and the immunity circuit 3.
3, the transmitting signal is inverted, and the ultrasonic head 4 and the other ultrasonic head 11 are driven in opposite phases. Furthermore, by adding the output of the ultrasonic head 4.11 with the adder 14, the transmitting waves having opposite phases to each other,
Only No. 4 (transmission frequency component) is removed, and only the reception signal can be extracted. Then, the output of this booster 14 is amplified by an amplifier 15, and this increase +11
The II unit 15 uses a bandpass filter or a tuned amplifier to eliminate distortion in the output of the adder 14.Furthermore, the output of this amplifier 15 and the transmission signal are mixed by a mixer 6, A moving object can be detected by performing detection, amplification, and discrimination.

1 Effects of the Invention 1 As described in 1, the present invention includes an oscillator that oscillates a frequency signal in the ultrasonic range, and a continuous ultrasonic wave with wave number signals of two ultrasonic heads that transmit waves to a monitoring space in a monitoring area and receive reflected waves from a target object in the monitoring space, and direct the output of the two ultrasonic heads. (t) transmitting frequency component removing means for canceling and removing the transmitting frequency component by using the outputs of the two ultrasonic heads containing the transmitting frequency component of the oscillator output, and extracting only the received wave component; , the received wave component from the transmitting frequency component removing means and the frequency (M
Equipped with a detection means for detecting Doppler No. 43 generated by a reflected wave from a moving object.1. Therefore, a moving object detection device with an integrated transmitter and receiver can be used to
When performing local surveillance of a location, to remove the transmitted wave frequency components from the output of the ultrasonic herad, each of the transmitted wave components contained in the two ultrasonic hends is input to the transmitted wave frequency component removal means. By canceling and removing the wave frequency components, in other words, by using the transmission frequency components included in the output from the 7D to both ultrasonic waves, the transmission frequency components can be removed. Therefore, the transmission frequency component is 7. - Since only the transmission frequency component removal means is used to eliminate the wave number components, it is not necessary to use two devices or bodies or to use two differential amplifiers as in the conventional method. Since each ultrasonic head has the same impedance, the transmitted waveforms are the same, so the transmitting wave of the oscillator J) can be simplified. Cancel the frequency components (remove with 7,
This has the effect of improving the transmit frequency frequency removal performance by 1-1.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, Fig. 2 is a block diagram of another embodiment of the same 1-, Fig. 3 is a block diagram of the R example, and Fig. 4 is another conventional example. FIG. 1 is an oscillator; 4. , ill and ultrasonic heads, 5 is a differential amplifier, and 14 is an adder.

Claims (1)

[Claims] (1) An oscillator that oscillates a frequency signal in the ultrasonic region, and a frequency signal from this oscillator that continuously transmits ultrasonic waves to the monitoring space of two independent monitoring regions, and also transmits ultrasonic waves to a target object in the monitoring space. Two ultrasonic heads each receive the reflected waves from the two ultrasonic heads, and the outputs of the two ultrasonic heads are directly input to the outputs of the two ultrasonic heads that include the transmission frequency component of the oscillator output. a transmitting frequency component removing means for canceling and removing the transmitting frequency component and extracting only the received wave component;
A moving object detection device comprising a detection means for detecting a Doppler signal generated by a reflected wave from a moving object using a received wave component from the transmitted wave frequency component removal means and a frequency signal from the oscillator.