JP5316979B2 - Individual movement monitoring device for slave unit - Google Patents

Description

The present invention relates to the individual mobile monitoring equipment handset.

  Conventionally, using a Doppler sensor using microwaves or millimeter waves, the speed of a moving body is obtained, the presence or absence of a moving body, the presence or absence of changes in the moving direction and relative distance, etc., are monitored, and the specified conditions are met. There has been known a moving body detection / notification system that performs notification in the case of a failure (Patent Document 1).

  However, in a general Doppler sensor, when a plurality of objects move, it is difficult to individually detect the movement of each object. Therefore, as shown in Patent Document 2, a method is known in which reflected waves from an object are received by a plurality of receiving units, and movements of the plurality of objects are detected by calculation based on reception states of the plurality of receiving units.

  In addition, when testing / evaluating a Doppler sensor device or the like (base unit, etc.) that measures the speed of a moving object, the test signal corresponding to the speed of the moving object to be detected / measured is generated at that speed. A moving reflector is required. However, there is a problem that it is difficult and dangerous to actually move the reflector on the work table.

In view of this, for example, a Doppler effect generating device has been devised in which a rotating drum is irradiated with radio waves from a transmitting device and radio waves reflected from the drum surface are received by a receiving device to obtain a Doppler effect due to a change in the peripheral speed of the drum surface ( Patent Document 3).
JP 2005-182256 A JP 2002-372577 A JP-A-7-270521

  When a plurality of receiving units are provided as in the invention disclosed in Patent Document 2, there is a problem that the circuit scale becomes large and the configuration of the Doppler sensor becomes complicated. In addition, the frequency of radio waves such as microwaves / millimeter waves for each slave unit may be different, and the master unit may receive these. However, this increases the circuit scale of the slave unit. This is disadvantageous in terms of size, power consumption, cost, and the like. Furthermore, the carrier frequency needs to be tuned between the slave unit and the master unit, and signals generated by the slave units may interfere with each other. In addition, since a transmitter for radio waves such as microwaves / millimeter waves is required for the slave unit, a technical conformity application is required.

  In the invention disclosed in Patent Document 3, since a test signal is generated based on a mechanical operation such as rotation, it is difficult to ensure an accurate speed and a stable reflection level. In particular, it is difficult to actually move the reflector on the workbench at high speed, and it is difficult to generate a test signal for an object moving at high speed.

Therefore, the present invention uses a Doppler sensor that utilizes radio waves such as microwaves and millimeter waves, has a small and simple circuit scale on the handset side, consumes less power, can be reduced in size, and can be used as a carrier between handset units. tuning of the frequency is not required, without interference handset each other, and to provide a separate mobile monitoring equipment of the child machine technology compatible application handset also unnecessary.

To achieve the above object, the individual mobile monitoring device of the slave unit according to the present invention, the individual mobile monitoring handset and a base unit for detecting the movement of the individual to a plurality of slave unit and said plurality of slave unit Device . Child machine, an antenna, an oscillator for generating a baseband signal, and inputs the baseband signal generated by the oscillator, and a variable impedance unit for varying the impedance to the antenna, the child machine The oscillator generates a baseband signal having a different frequency for each slave unit, and the master unit generates a local oscillator that generates a radio wave such as a microwave / millimeter wave having a predetermined frequency, a transmission antenna that radiates the radio wave, wherein a receiving antenna for receiving a reflected wave of the electromagnetic wave emitted, and mixing means for mixing the radio waves to output the reflected wave received from the receiving antenna from the local oscillator, the output of the mixing means from the transmitting antenna and discriminating means for discriminating the frequency diverse signals based on a frequency different for each handset, is discriminated for each slave unit by said discrimination means And to and detection means for detecting a slave having moved based on the frequency diverse signals.

In this way, the master unit emits a radio wave of a microwave / millimeter wave or the like of a predetermined frequency generated by the local oscillator from the transmitting antenna, the slave unit, by inputting a base band signal generated by the oscillator Impedance varying means varies the impedance of the slave unit with respect to the antenna. As a result, the radio wave transmitted from the master unit is reflected by the impedance variable means of the slave unit, which is modulated by impedance mismatch. That is, the amplitude of the reflected wave changes based on the baseband signal (amplitude modulation is applied).

The base unit receives the reflected wave of the radio wave radiated from the transmission antenna from the reception antenna, and mixes the received radio wave and the radio wave output from the local oscillator by a mixing unit. Here, the signal obtained from the mixing means, that is, the baseband signal is a signal related to both the amplitude and the phase of reflection. Since the oscillator of each slave unit generates a different frequency for each slave unit, the frequency of the baseband signal obtained from the mixing unit of the master unit corresponds to the impedance variable frequency for each slave unit. Therefore, the master unit discriminates the output of the mixing unit into a signal for each frequency based on a frequency different for each slave unit by a discrimination unit. Then, the master unit detects individual movements of the slave units based on the frequency-specific signals discriminated by the discrimination unit by the state detection unit.

Furthermore, the slave unit does not require an oscillator of a radio wave such as a microwave / millimeter wave, and a technical conformity application is not required. In addition, since the reflected wave emitted from the master unit is used, it is not necessary to tune the carrier frequency between the slave unit and the master unit, and the frequency generated by the oscillator of each slave unit is different, so it is reflected by the slave unit. There is no possibility that the received signals interfere with each other. Further, the circuit scale of the slave unit can be reduced, which is advantageous in terms of size, power consumption, cost, and the like. Further, it is not necessary to provide a plurality of receiving units for each slave unit, and the circuit scale can be reduced, which is advantageous in terms of size, power consumption, cost, and the like. Moreover, it is good for the state of the detection target in the state detection system demonstrated below to be a movement of an individual subunit | mobile_unit.

  The master unit can be configured using, for example, a Doppler sensor. Further, the impedance variable means of the slave unit can be configured using, for example, a detection diode. According to such a configuration, a baseband signal is applied to the detector diode of the detector, and the operating impedance of the detector diode changes. Therefore, when a radio wave such as a microwave / millimeter wave is received from the Doppler sensor, it responds to the impedance mismatch. Changes the reflection level. Therefore, for example, amplitude modulation can be easily applied to a radio wave such as a microwave / millimeter wave which is a reflected wave. By receiving this reflected wave, the Doppler sensor can obtain a Doppler signal by multiplying the signal from the local oscillator by the received wave.

  This multiplied output is a level due to the amplitude and phase of the reflected wave. When the reflected wave is amplitude-modulated, this Doppler sensor output outputs a detection signal having an amplitude corresponding to the level fluctuation of the reflected wave. Even if the level of the reflected wave is constant, a change in the detection signal also appears when the phase changes. The phase here refers to the phase of the received wave with respect to the phase of the local oscillator, and depends on the relative distance between the master unit and the slave unit. Here, the relationship between the local oscillation signal, the reflected signal, and the Doppler sensor output in the non-modulated reflected wave is shown in FIG. 1, the change in relative distance in this state versus the output level of the Doppler sensor in FIG. 2, and the modulated reflection. FIG. 3 shows the relationship between the reflected signal in the wave, the local oscillation signal vector of the Doppler sensor, and the Doppler sensor output, and FIG. 4 shows the Doppler sensor output level versus the modulation signal at each relative distance in this state. FIG. 5 shows the amplitude waveform of distance versus Doppler sensor output, and FIG. 6 shows the waveform through the AC amplifier. In the case of a reflected wave that is not modulated, since the Doppler sensor output is a direct current, it is difficult to detect a slow change in distance or a minute change in distance due to problems such as drift. On the other hand, when the reflected wave is modulated, since the Doppler sensor output is alternating current, a high gain AC amplifier that cuts the direct current and drift components can be used, which is advantageous in that there is no influence of drift. is there. In addition, by using a narrowband filter that removes frequencies other than the target frequency in the detection circuit, not only the baseband signal from the slave unit that is not the target can be removed, but also the detection level can be detected even at a finer level. .

  (2) Further, as another solution, a state detection system comprising a plurality of slave units and a master unit that monitors the status of the plurality of slave units, wherein the slave unit includes an antenna, a baseband signal Signal generating means for generating the impedance, and impedance varying means for varying the impedance with respect to the antenna based on the baseband signal generated by the signal generating means. The base unit generates a radio wave such as a microwave / millimeter wave having a predetermined frequency, a transmission antenna that radiates the radio wave, and the transmission antenna. A receiving antenna that receives a reflected wave of a radio wave radiated from the radio wave, and a radio wave received from the receiving antenna is mixed with a radio wave output from the local oscillator First mixing means, second mixing means for mixing radio waves received from the receiving antenna with radio waves output from the local oscillator, and outputs of the first mixing means and the second mixing means based on the different frequencies Discriminating means for discriminating each signal according to frequency, and status detecting means for detecting a status related to the slave unit based on the baseband signal for each frequency discriminated by the discriminating means, the first mixing The means and the second mixing means are arranged at a predetermined distance from each other.

  That is, in the present invention, the frequency-dependent signals are discriminated based on different frequencies for each slave unit, but the output of the mixing means is obtained by phase modulation according to the position of the slave unit and the impedance variable means of the slave unit. Due to the influence of both of the produced amplitude-modulated reflected waves, there is a position where the output signal of the mixing means cannot be obtained (becomes only a DC signal) depending on the positional relationship between the slave unit and the master unit. The section of FIG. 6 (b ′, b ″, d ′, d ″ in the figure) corresponds to this position. This position is hereinafter referred to as a dead zone. Therefore, in order to eliminate such a dead zone, as in the invention of (2), it is preferable to provide two mixing means in the master unit and arrange the two mixing means at positions separated by a predetermined distance.

  In particular, the predetermined distance may be set to 1/8 of the wavelength of a radio wave such as a microwave / millimeter wave emitted from the master unit as in the invention of (3). In this way, the output of one mixing means and the output of the other mixing means are signals that are 90 degrees out of phase, so even if one output is a direct current signal, the other reliably An AC signal is output.

  Further, (4) the discrimination means includes a first discrimination means for discriminating an output of the first mixing means into a frequency-specific signal based on the different frequencies, and an output of the second mixing means based on the different frequencies. And a second discriminating means for discriminating the signals according to frequency, wherein the state detecting means includes two signals in the same frequency band discriminated by the first discriminating means and the second discriminating means. It is good to comprise so that the state regarding the said subunit | mobile_unit corresponding to the same frequency band may be detected based on a high level signal. By adopting such a configuration, a dead zone can be eliminated and a more accurate state can be detected.

  The state detection means can be configured to detect, for example, the presence / absence of the movement of the slave unit or the presence / absence of the movement of the object between the slave unit and the master unit. For example, as in the invention of (5), when there is a change in the level of the signal for each frequency output by the discrimination unit, the state detection unit changes the state of the slave unit having the signal generation unit corresponding to the frequency. It is good to judge that there was.

  (6) Further, the discrimination means may be configured by, for example, at least one of FFT, a correlator, and a plurality of BPFs. In particular, when the number of slave units is as small as several, it can be constructed at a low cost if it is composed of a plurality of BPFs.

  (7) The power source of the slave unit is preferably a battery. Since the handset of the present invention has a smaller circuit scale and lower power consumption than the conventional one, the power source can be a battery.

  (8) A child device (electronic device) according to the present invention is a child device in a state detection system including a plurality of child devices and a parent device that monitors states of the plurality of child devices, and includes an antenna and a baseband signal Signal generating means, and impedance varying means for varying the impedance to the antenna based on the baseband signal generated by the signal generating means, wherein the signal generating means constitutes the state detection system A baseband signal having a frequency different from that of other slave units is generated.

  (9) An electronic apparatus according to the present invention includes the configuration of the parent device in the state detection system according to any one of (1) to (6).

  (10) A reflector according to the present invention is based on an antenna, signal generation means for generating a baseband signal, setting means for setting a frequency of the baseband signal, and a baseband signal generated by the signal generation means. Impedance varying means for varying the impedance to the antenna.

  A local oscillator, a mixing unit, an antenna, and the like in the base unit can be configured using an existing Doppler sensor. Conventionally, there is a device that measures the moving speed of an object using such a Doppler sensor. When designing and manufacturing such devices, it is necessary to test whether these devices are measuring the correct speed. Conventionally, the moving speed is measured by actually moving the object at a predetermined speed, but it is difficult to ensure an accurate speed and a stable reflection level. In particular, it is difficult to actually move the reflecting object (measurement object) at a high speed on a work table or the like.

  Therefore, this problem can be solved by using the configuration of the slave unit in the above-described state detection system. For example, the reflector shown in (10) may be used as a test signal generator for a speed measuring device using a Doppler sensor. In this way, the output signal of the mixing means corresponding to the moving speed can be obtained without moving the measurement object. That is, with such a simple reflector, a pseudo Doppler signal having an arbitrary frequency can be generated for the Doppler sensor. In particular, it is easy to generate a test signal relating to an object moving at high speed, and a reflected wave with an accurate velocity can be obtained. Also, a stable reflection level can be ensured. For example, a test signal corresponding to several hundred km / h can be easily generated with a small, simple and safe configuration.

* Relationship of Inventions According to Claims The inventions according to claims 8 and 9 form part of the state detection system according to any one of claims 1 to 7. In other words, the state detection system according to any one of claims 1 to 7 is configured by combining the invention according to claim 8 and the invention according to claim 9. Furthermore, the invention described in claim 10 adopts the same configuration as that of one slave unit constituting the state detection system of the present invention. In other words, the slave unit of the present invention becomes a reflector and can be used as a device that generates the test signal.

  In the present invention, while using a Doppler sensor utilizing radio waves such as microwaves and millimeter waves, the circuit scale on the handset side is small and simple, consumes less power, can be miniaturized, and the carrier frequency between handset units is Although all of them are the same, the modulation baseband frequencies are different, so that each slave unit can be recognized individually, and an application for technical conformance of the slave units is not required. Also, a device having the configuration of the slave unit can generate a test signal corresponding to the speed of the moving object to be measured in the speed measuring device or the like.

FIG. 7 shows a preferred embodiment of the individual movement monitoring apparatus for a slave according to the present invention. As shown in FIG. 7A, the individual movement monitoring device for the slave unit is a system including a master unit 1 and a plurality of slave units 2. Base unit 1 includes a microwave Doppler sensor, and has a function of radiating a microwave having a predetermined frequency and receiving a reflected wave thereof. The plurality of slave units 2 have a function of reflecting the microwave radiated from the master unit 1, and the modulation frequency of the reflected wave reflected from the slave unit 2 to the master unit 1 is different for each slave unit 2. I have to. Thereby, the main | base station 1 can discriminate | determine which reflected wave from which subunit | mobile_unit from the difference in the frequency of the baseband signal obtained by a mixing means. The specific configuration of the master unit 1 and the slave unit 2 is as follows.

  The base unit 1 includes a microwave Doppler sensor 10, an amplifier 11 that amplifies the IF output of the microwave Doppler sensor 10, a plurality of bandpass filters 12 connected in parallel to the output of the amplifier 11, and each bandpass filter 12. And an IF detector circuit 13 connected to the output. The plurality of band-pass filters 12 and the IF detector 13 constitute a discrimination circuit.

  Specifically, as shown in FIG. 7B, the microwave Doppler sensor 10 of the base unit 1 includes a local oscillator 10a that generates a microwave having a frequency of 24.15 GHz, and a micro wave generated by the local oscillator 10a. A transmitting antenna 10b that radiates waves, a receiving antenna 10c that receives a reflected wave of the microwave radiated from the transmitting antenna 10b, and a microwave that is received by the receiving antenna 10c is mixed with a microwave that is output from the local oscillator 10a. And a mixer 10d which is a mixing means. The IF signal mixed by the mixer 10d is supplied to the amplifier 11.

  The plurality of band pass filters 12 have different pass bands. Thereby, the amplified IF signal output from the amplifier 11 is separated for each frequency band. That is, since the frequency of the modulation applied to the reflected waves from the plurality of slave units 2 is set to be different for each slave unit 2, the frequency of this IF signal is also different for each slave unit. The same can be said for other slave units. Therefore, the IF signal based on the reflected wave from the corresponding slave unit (x) is allowed to pass through the pass band of each bandpass filter 12 (BPF (x)), and all the other than the corresponding slave unit (x) are passed. The IF signal based on the reflected wave from the slave unit was set not to pass.

  The IF detection circuit 13 detects a signal that has passed through each bandpass filter 12 and outputs a detection signal. Therefore, a signal based on the reflected wave from the slave unit (x) is output to the output terminal of the IF detection circuit 13 connected to the BPF (x).

  On the other hand, as shown in FIG. 7C, the handset 2 is connected to the antenna 23, a baseband signal generator (oscillator (OSC)) 21 that is a signal generating means for generating a baseband signal, and the antenna 23. And an impedance variable device 22 for inputting the baseband signal generated by the baseband signal generator 21 and changing the impedance with respect to the antenna. For example, a detection diode or FET can be used as the impedance variable device 22. The impedance variable device 22 and the antenna 23 constitute a detector 24. In addition, although illustration is abbreviate | omitted, the power supply to each part of the subunit | mobile_unit 2 may use a solar cell and a button battery, and may use a dry cell and a storage battery.

  The baseband signal generator 21 of each slave unit 2 is set to generate baseband signals having different frequencies of OSC (1) to OSC (n) as shown in FIG. In each slave unit 2, the impedance variable means varies the impedance of the slave unit with respect to the antenna based on the baseband signal generated by the baseband signal generator 21. As a result, the microwave transmitted from the parent device 1 is reflected by impedance mismatching in the impedance variable device 22 of the child device 2. That is, the amplitude of the reflected wave changes based on the baseband signal generated by the baseband signal generator 21 (amplitude modulation is applied).

  Base unit 1 receives a reflected wave of a microwave radiated from transmitting antenna 10b of Doppler sensor 10 from receiving antenna 10c, and mixes the received microwave and a microwave output from local oscillator 10a by mixer 10d. Here, the signal obtained from the mixer 10d is a signal related to both the amplitude and phase of the reflected wave. Since the baseband signal generator 21 of each slave unit 2 generates a baseband signal having a different frequency for each slave unit 2, the frequency of the IF signal generated by the master unit 1 is different for each slave unit 2. . Further, in the configuration of FIG. 7, the level of the demodulated wave output to the IF output terminal of the Doppler sensor 10 varies greatly due to a minute change (in the order of several mm) of the relative distance between the Doppler sensor 10 and the detector 24.

  Therefore, the master unit 1 discriminates IF output signals for each signal based on each slave unit 2 by a plurality of band-pass filters 12, and individually monitors changes in the respective signal levels, so that It is possible to detect movement individually. That is, it is possible to monitor the status such as whether or not the slave unit has moved.

  When the level of each detection signal output from the IF detection circuit 13 changes by a predetermined value or more, the parent device 1 outputs an alarm device that outputs a different alarm with sound and video for each detection signal corresponding to each child device 2. (Not shown). For example, when there is a change in the detection signal level related to the slave unit (1) by a predetermined value or more, an audio and video alarm such as “An error has occurred in the slave unit (1)” is output (other slave units). The same).

  For example, the slave unit (1) is pasted on a door or window, the slave unit (2) is pasted on the back of a painting, the slave unit (3) is placed on an information device such as a personal computer, and the slave unit (4) On the back of the equipment. Then, when the detection signal level related to the child device (1) has changed by a predetermined value or more, the parent device 1 outputs an alarm such as “An error has occurred in the door” and the detection signal related to the child device (2). If the level changes more than a predetermined value, an alarm such as “An anomaly has occurred in the painting” is output. If the detection signal level related to the slave unit (3) changes more than a predetermined value, An alarm such as “Abnormality has occurred” is output, and if there is a change in the detection signal level related to the slave unit (4) that exceeds a predetermined value, an alarm such as “A fault has occurred in the device” is output. Moreover, you may attach this subunit | mobile_unit to what stored valuables, such as a safe, a piggy bank, and a jewelry box, and various other things.

  In this way, individual movement of the slave unit 2 can be detected by the single master unit 1 and the plurality of slave units 2 that are reflectors that do not have an oscillator for the carrier frequency of the radio wave. That is, this state detection system can be used as an individual movement monitoring device that monitors individual movements for each slave unit 2.

  The base unit 1 can be configured to use an FFT 14 as shown in FIG. 8 in place of the discrimination circuit including the plurality of bandpass filters 12 and the IF detection circuit 13 shown in FIG. When the number of slave units is about several, a discrimination circuit composed of a plurality of band-pass filters or the like is advantageous in terms of cost as shown in FIG. 7, but when the number of slave units 2 is large, May be discriminated using an FFT 14 as shown in FIG. By using FFT14 as the discrimination circuit, it is possible to increase the number of channels and improve the SN ratio (higher sensitivity).

  Further, instead of the discriminating circuit including the plurality of bandpass filters 12 and the IF detection circuit 13 shown in FIG. 7, the bandpass filter 12 and the IF detection circuit 13 may be correlators. That is, the BPF (1) and DET portions of FIG. 7A are used as the correlator (1) for correlating the baseband signal of the slave unit (1), and the BPF (2) and DET portions are set as the slave units (1). 2) Correlator (2) that correlates with the baseband signal, and BPF (n) and DET are correlators (n) that correlate with the baseband signal of the slave unit (n). . The correlator can be composed of, for example, a product-sum calculator. In addition, the correlation waveform of the correlator can be a rectangular wave by making the modulation signal of the slave unit 2 a rectangular wave. This eliminates the need for multiplication in the correlation calculation, and can be used even by a processor with low capability.

  Furthermore, the discrimination circuit discriminates the frequency-specific signals based on the frequency of the baseband signal that differs for each slave unit 2, but the output of the mixer is a phase modulation according to the position of the slave unit 2, and the slave unit Depending on the positional relationship between the slave unit 2 and the master unit 1, the output signal of the mixer cannot be obtained due to the influence of both the amplitude-modulated reflected wave generated by the impedance variable unit 2 (only the DC signal is obtained). ) Position (dead zone) exists (the section in FIG. 5).

  Therefore, the base unit 1 is more preferably configured to use a two-output microwave Doppler sensor as shown in FIG. As shown in FIG. 10B, the two-output microwave Doppler sensor includes a local oscillator 10a that generates a microwave having a frequency of 24.15 GHz, and a transmission antenna 10b that radiates the microwave generated by the local oscillator 10a. A receiving antenna 10c that receives a reflected wave of the microwave radiated from the transmitting antenna 10b, a first mixer 10d that mixes the microwave received from the receiving antenna 10c with the microwave output from the local oscillator 10a, and a receiving antenna A second mixer 10e that mixes the microwave received from 10c with the microwave output from the local oscillator, and the first mixer 10d and the second mixer 10e are separated by a distance corresponding to λ / 8. It is installed.

  The two outputs IF1 and IF2 of the Doppler sensor 10 are amplified by IF amplifiers 11a and 11b, respectively, and then input to the first discrimination circuit 16a and the second discrimination circuit 16b. The first discrimination circuit 16a and the second discrimination circuit 16b have the same configuration. Each discriminating circuit has the same configuration as that of the discriminating circuit including the plurality of band-pass filters 12 and the IF detection circuit 13 shown in FIG.

  And the detector which detects the state regarding a subunit | mobile_unit based on a high level signal by comparing two signals of the same frequency band each discriminated by the first discrimination circuit 16a and the second discrimination circuit 16b is provided. That is, an output signal for the child device (1) of the first detection circuit 16a and an output signal for the child device (1) of the second detection circuit 16b are input, and the child device ( 1) Detect the state related to. For the slave unit (2)..., The same circuit is provided for the slave unit (n) to detect the state related to each slave unit.

  In this way, the output of one mixer and the output of the other mixer are signals that are 90 degrees out of phase, so even if one output is only a DC signal, the other is reliably Since an AC signal is output and the state is determined based on the signal with the higher output level, the influence of the dead zone can be eliminated.

  The subunit | mobile_unit of this embodiment can be used as a test signal generator for speed measuring devices using a Doppler sensor. That is, conventionally, there is a high-speed moving object sensor device that measures the moving speed of a high-speed moving object using a Doppler sensor. When designing and manufacturing such devices, it is necessary to test whether these devices are measuring the correct speed. Conventionally, the moving speed is measured by actually moving the object at a predetermined speed, but it is difficult to ensure an accurate speed and a stable reflection level. In particular, it is difficult to actually move the reflecting object (measurement object) on a work table or the like at high speed, and it is also difficult to generate a test signal relating to an object moving at high speed.

  Therefore, as shown in FIG. 10, the slave unit 2 shown in FIG. 7C may be placed facing the high-speed moving object sensor device 30. That is, the subunit | mobile_unit 2 is provided with the antenna, the baseband signal generator which generate | occur | produces a baseband signal, and the impedance variable device which varies the impedance with respect to an antenna based on the baseband signal generated by the baseband signal generator. The slave unit configured as described above can be used as a test signal generator for a speed measuring device using a Doppler sensor.

  In this way, the output signal of the mixer corresponding to the moving speed can be obtained without moving the measurement object. That is, with such a simple reflector, a pseudo Doppler signal having an arbitrary frequency can be generated for the Doppler sensor. In particular, it is easy to generate a test signal relating to an object moving at high speed, and a reflected wave with an accurate velocity can be obtained. Also, a stable reflection level can be ensured. For example, a test signal corresponding to several hundred km / h can be easily generated with a small, simple and safe configuration.

  In each of the above-described embodiments, examples using microwaves have been described. However, the present invention is not limited to this, and millimeter waves and other frequency bands may be used.

It is a figure which shows the relationship between the local oscillation signal in an unmodulated reflected wave, a reflected signal, and a Doppler sensor output. It is a figure which shows the variation | change_quantity of the relative distance in the state of FIG. 1, and the output level of a Doppler sensor. It is a figure which shows the relationship between the local oscillation signal in a modulation | alteration reflected wave, a reflected signal, and a Doppler sensor output. It is a figure which shows the time of a Doppler sensor output level of the modulation signal in each relative distance in the state of FIG. It is a figure which shows the amplitude waveform of the relative distance versus the Doppler sensor output in the state of FIG. It is a figure which shows the waveform which passed AC amplifier. It is a figure which shows suitable one Embodiment of this invention. It is a figure which shows the modification of this embodiment. It is a figure which shows the modification of this embodiment. It is a figure which shows another usage pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Master machine 2 Slave machine 10 Microwave Doppler sensor 11 Amplifier 12 Band pass filter 13 IF detection circuit 21 Baseband signal generator 22 Impedance variable device 23 Antenna

Claims (7)

An individual movement monitoring device for a slave unit comprising a plurality of slave units and a master unit that detects individual movements of the plurality of slave units,
The slave is
An antenna,
An oscillator that generates a baseband signal;
Impedance variable means for inputting a baseband signal generated by the oscillator and varying the impedance to the antenna;
With
The oscillator of each slave unit generates a baseband signal having a different frequency for each slave unit,
The base unit is
A local oscillator that generates radio waves such as microwaves / millimeter waves of a predetermined frequency;
A transmitting antenna that radiates the radio wave;
A receiving antenna that receives reflected waves of radio waves radiated from the transmitting antenna;
Mixing means for mixing the reflected wave received from the receiving antenna with a radio wave output from the local oscillator;
Discriminating means for discriminating the output of the mixing means into signals according to frequency based on different frequencies for each slave unit;
Detecting means for detecting a slave unit that has moved based on the signal for each frequency discriminated for each slave unit by the discrimination unit;
An individual movement monitoring device for a slave unit comprising:   2. The slave unit according to claim 1, wherein the detection unit is configured to detect whether or not the slave unit has moved based on a change in a phase of a reflected wave with respect to a phase of a radio wave output from a local oscillator. Individual movement monitoring device.   3. The detection unit according to claim 1, wherein when the signal level of the signal for each frequency is changed, the detection unit detects a movement of a slave unit having an oscillator corresponding to the frequency. The individual movement monitoring device for the slave unit described. The discrimination means is a correlator;
The individual movement monitoring apparatus for a slave unit according to any one of claims 1 to 3, wherein the baseband signal generated by the oscillator is a rectangular wave.   The individual movement monitoring apparatus for a slave unit according to any one of claims 1 to 3, wherein the discrimination means is an FFT.   The individual movement monitoring device for a slave unit according to any one of claims 1 to 5, further comprising an alarm device that outputs a different alarm for each slave unit when the detection unit detects the movement of the slave unit.   The individual movement monitoring device for a slave unit according to any one of claims 1 to 6, wherein the power source of the slave unit is a solar battery or a button battery.

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