JP2003279643A - Body detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relatively inexpensive body detector of relatively simple detector constitution capable of enhancing detection precision for a stationary body within a close distance and a detecting object of a low moving speed. <P>SOLUTION: The body detector is constituted so that a sensor unit 4 transmits a transmission signal 2 to the detection object 1 and receives a reflected reception signal 3, a signal processing part 6 outputs output signals 5, in which phase difference different from each other are generated and outputted from a phase difference generating means inside the sensor unit 4, and processes the output signals 5, and a determining part 8 compares a detection signal 7 from the signal processing part 6 with a threshold level to determine the presence of the detection object. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor device for sensing by transmitting and receiving radio waves, which can obtain an output suitable for determining the presence or absence of an object,
The present invention also relates to an object detection device that determines the presence or absence of an object based on the output from the sensor device.

[0002]

2. Description of the Related Art Conventionally, pulse radars, FM-CW radars and the like have been known as devices for detecting an object by using transmission and reception of radio waves. The pulse radar, from the time when the pulsed radio wave is emitted, the pulsed radio wave hits the target object,
The distance from the device to the target object is measured by the length / shortness of the time required for the light to be reflected and returned to the device. Further, the FM-CW radar measures the beat frequencies of a transmission signal and a reflection signal generated by subjecting a continuous wave (CW) signal radiated from the device to frequency modulation (FM) with, for example, a sawtooth wave. Then, the distance from the device to the object is measured.

[0003]

The pulse radar described above measures the distance from the device to the object by the length / shortness of the time from the time when the radio wave is emitted to the time when the radio wave is received. Therefore, it is not suitable for distance measurement when the target object exists at a short distance. Moreover, there is a problem that the device configuration is relatively complicated and expensive. On the other hand, the FM-CW radar is configured to obtain the distance from the device to the target object by measuring the beat frequency of the transmission signal and the reflection signal caused by the signal processing as described above. When the target object is present at a short distance, it is necessary to change the frequency greatly, so that the occupied frequency bandwidth of the transmission signal is widened, which is also unsuitable. Moreover, similarly to the above-mentioned pulse radar, there is a problem that the device configuration is relatively complicated and expensive. Therefore, the pulse radar and FM-
A method of using a Doppler radar as a means for detecting an object without using the CW radar has also been studied. But,
The Doppler radar is very effective when detecting an object that moves at high speed such as an aircraft or an automobile, but the detection target is, for example, the human body, and is omitted just before the toilet when trying to use it in the toilet. There is also a problem that it is not suitable for detecting a human body standing in a stationary state and the price is high. Therefore, when detecting an object such as a human body that has a slow moving speed and is stationary, a radio wave belonging to a predetermined frequency band is radiated to the target object, and the radiated radio wave and the target object are reflected and reflected. A method of receiving the standing wave generated by the returning radio wave as a reception signal and measuring the intensity of the standing wave to detect the target object has been studied. However, as a problem when performing detection by measuring the strength of the standing wave,
Since the abdomen having a large amplitude and the node having a small amplitude are periodically present in the cycle, the distance from the device to the object cannot be uniquely determined only by the intensity of the standing wave. Therefore, the present invention provides an object detection device that can improve the detection accuracy of a target object that is stationary or has a slow moving speed in a short distance and that has a relatively simple device configuration and that is relatively low in cost. It is in.

[0004]

Means for Solving the Problems and Actions / Effects In order to solve the above problems, the present invention as set forth in claim 1 is a signal generating means for generating a transmission signal for transmitting a signal as an electric wave to the outside, A transmission unit connected to the signal generation means by a transmission wave transmission line to transmit a transmission signal to the outside, a plurality of reception units receiving signals received as radio waves from the outside as reception signals, the reception unit and reception wave transmission A plurality of signal converters that are connected by a path and extract low-frequency output signals based on the received signals and the transmitted signals; and an output stage that outputs the output signals converted by the signal converters for each of the receivers. , A phase difference generating means for generating a phase difference so that the phase differences of the plurality of output signals are different from each other, and a plurality of output signals output from the respective output stages of the sensor device to an arbitrary reference voltage. To By performing full-wave rectification by performing full-wave rectification, and comparing the detection signal with a preset threshold that can be detected by a signal processing unit that extracts a detection signal that is the maximum value locus of each full-wave rectified signal. A determination unit that detects the presence or absence of an object,
It is characterized by having. With such a configuration, since the phases of the output signals obtained from the output stages by the phase difference generation means are all different, it is possible to suppress periodic fluctuations of the output signals by performing signal processing on these output signals. Since the signal can be output according to the distance, it is possible to detect a stationary object within a predetermined range with high accuracy.

Further, according to a second aspect of the present invention, the phase difference generating means is a reception wave transmission line having a different length from each of the receiving sections to the signal converting section.
With such a configuration, by setting the lengths of the reception wave transmission lines from the receiving units to the signal converting unit to different lengths, a phase difference occurs in the reception signal according to each line length, and a phase difference also occurs in the output signal. Therefore, by processing these output signals, periodic fluctuations of the output signals can be suppressed and the detection signal can be output according to the distance. Therefore, the detection of a stationary object within a predetermined range is highly accurate. Can be detected with.

Further, according to a third aspect of the present invention, the phase difference generating means is a signal in which the respective reception wave transmission lines and the transmission wave transmission line with respect to the respective reception parts approach each other at different positions in order to convert the signals. It is a converter.
With such a configuration, by changing the location of each signal conversion unit, a phase difference occurs between the transmission wave used for signal conversion and each reception wave, and thus a phase difference also occurs in each output signal. By processing the signal, the periodic fluctuation of the output signal can be suppressed and the detection signal can be output according to the distance. Therefore, it is possible to detect a stationary object within a predetermined range with high accuracy.

Also, in the present invention, the phase difference generating means is a reception wave transmission line having a different length from each of the receiving sections to the signal converting section, and each receiving wave transmission path is used to convert a signal. It is characterized in that the received wave transmission line and the transmitted wave transmission line with respect to a unit are signal conversion units that approach each other at different positions. In this way, by changing the length of the reception wave transmission line from each reception unit to the signal conversion unit and changing the location of the approaching signal conversion unit of each reception wave transmission line and the transmission wave transmission line, , When changing the phase of the output signal, shift the phase by changing the location of the signal converter when it is not possible to secure a space to change the length of the received wave transmission path to the set value for changing the phase. It is possible to realize downsizing of the device.

According to a fifth aspect of the present invention, the phase difference generating means is a transmission wave transmission line having different lengths from the signal generating means to the signal converting section. With such a configuration, by making the lengths of the transmission wave transmission lines from the signal generation unit to the signal conversion unit different from each other, a phase difference occurs in the transmission signals according to each line length,
Since a phase difference also occurs in the output signals, by performing signal processing on these output signals, periodic fluctuations in the output signals can be suppressed, and the detection signal can be output according to the distance. It is possible to detect an object with high accuracy.

According to a sixth aspect of the present invention, the phase difference generating means is a reception wave transmission line having a different length from each of the receiving sections to the signal converting section, and the signal generating section to the signal converting section. Up to the transmission wave transmission line having different lengths. With this configuration,
By changing the length of the reception wave transmission line from each receiving unit to the signal conversion unit and changing the length of the transmission wave transmission line from the signal generation unit to the signal conversion unit, the phase of the output signal can be changed. When changing the length, it is possible to shift the phase by changing each length of the transmission wave transmission line when it is not possible to secure a space to change the length of the reception wave transmission line to the set value for changing the phase. Therefore, it is possible to realize the miniaturization of the device.

Further, the invention according to claim 7 is that a transmission unit which is connected to the signal generation means by a transmission wave transmission line to transmit a transmission signal to the outside, and a reception unit which receives a signal received as a radio wave from the outside as a reception signal. And a plurality of signal conversion units that are connected to the reception unit by a reception wave transmission line that is branched in the middle to extract low-frequency output signals based on the reception signal and the transmission signal, and the output signal converted by the signal conversion unit. A sensor device having output stages for outputting the respective output signals and a phase difference generating means for producing a phase difference so that the phase differences of the plurality of output signals are all different, and a plurality of output devices from the output stages of the sensor device. A signal processing unit that performs full-wave rectification on an output signal at an arbitrary reference voltage and extracts a detection signal that is a locus of the maximum value of each full-wave rectified signal, and the detection signal and a presettable threshold value. A judging unit for detecting the presence or absence of an object by performing a comparison, and having a. With such a configuration, even when a space for providing a plurality of receiving units cannot be secured, a plurality of receiving signals can be obtained by one receiving unit by providing a branch point, and each output can be obtained by having a phase difference generating means. Since the phases of the signals are all different, by processing these output signals, periodic fluctuations of the output signals can be suppressed and the detection signal can be output according to the distance. The detection can be performed with high accuracy.

Also, in the present invention, the phase difference generating means is a reception wave transmission line having different lengths from a branch point of the reception wave transmission line to each of the signal conversion units. And With such a configuration, by setting the lengths of the reception wave transmission lines of the signal conversion unit from the branch points to different lengths, a phase difference occurs in the signal according to each line length, and a phase difference occurs in the output signal. By processing these output signals, periodic fluctuations of the output signals can be suppressed and the detection signals can be output according to the distance, so it is possible to detect stationary objects within a predetermined range with high accuracy. Becomes

According to a ninth aspect of the present invention, the phase difference generating means is a signal in which the reception wave transmission line and the transmission wave transmission line with respect to each output stage approach each other at different positions in order to perform signal conversion. It is a converter.
With such a configuration, by changing the location of each signal conversion unit, a phase difference occurs between the transmission wave used for signal conversion and each reception wave, and thus a phase difference also occurs in each output signal. By processing the signal, the periodic fluctuation of the output signal can be suppressed and the detection signal can be output according to the distance. Therefore, it is possible to detect a stationary object within a predetermined range with high accuracy.

According to a tenth aspect of the present invention, the phase difference generating means is a reception wave transmission line having different lengths from a branch point of the reception wave transmission line to each of the signal conversion units, and In order to perform conversion, the reception wave transmission line and the transmission wave transmission line for each output stage are signal conversion units that come close to each other at different positions. The phase difference generation means changes the length of the reception wave transmission line from the branch point to each of the signal conversion units, and in the signal conversion unit, the reception wave transmission line and the transmission wave transmission line approach each other. When changing the phase of the output signal by changing the location together, it is not possible to secure the space for changing the length of the received wave transmission path to the set value for changing the phase. It is possible to shift the phase by changing the location, and since multiple output signals can be obtained with a single receiving section without providing multiple receiving sections, it is possible to realize miniaturization of the device. Become.

In the eleventh aspect, the phase difference generating means is a transmission wave transmission line having a different length from the signal generating means to the signal converting section. With such a configuration, by making the lengths of the transmission wave transmission lines from the signal generation means to the signal conversion unit different from each other, a phase difference occurs in the transmission signals transmitted to the mixer unit according to each line length. , By processing these output signals, suppress periodic fluctuations of the output signals,
Since the detection signal can be output according to the distance, it is possible to detect a stationary object within a predetermined range with high accuracy.

In the twelfth aspect, the phase difference generating means is a reception wave transmission line having a different length from the branch point to the respective signal converting sections, and the signal generating section to the signal converting section. Up to the transmission wave transmission line having different lengths. According to this configuration, the phase difference generation means changes the length of the reception wave transmission path from the branch point to each of the signal conversion sections, and the length of the transmission wave transmission path from the signal generation means to the signal conversion section. When changing the phase of the output signal by changing the input signal, it is not possible to secure a space to change the length of the received wave transmission path to the set value for changing the phase. It is possible to shift the phase by changing the respective lengths, and it is possible to realize the miniaturization of the device.

According to a thirteenth aspect of the present invention, the receiving section is formed of a columnar antenna, and in the fourteenth aspect of the invention, the receiving section is a patch formed of a metal film on a flat substrate. It is characterized by being configured by an antenna. As described above, in the present invention, since the phase is shifted by changing the line length of the received wave transmission line or the location of the signal conversion unit, it does not depend on the shape of the antenna used in the reception unit. , A columnar antenna used as a three-dimensional antenna,
Even if a conventional antenna shape such as a patch antenna used as a planar antenna is used as it is, it is possible to improve the detection accuracy of stationary detection.

According to a fifteenth aspect of the present invention, the signal processing section includes a filter circuit for removing unnecessary signals included in the plurality of output signals. With such a configuration, by removing the noise included in the output signal before the signal processing by the filter circuit, it is possible to prevent the temporary increase or decrease of the output due to the noise from being recognized as the output signal. The value can be derived almost uniquely.

According to a sixteenth aspect of the present invention, the filter means is a variable filter means capable of changing the frequency band to be transmitted depending on the application. With such a configuration, when the sensor device of the present invention is provided in various devices, even when the object to be detected in each device is different, a filter circuit adapted to the detected object can be provided without replacing the filter device itself. It becomes possible to configure.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a sensor device according to the present invention, FIG. 2 is a schematic configuration diagram of a surface of a sensor device that has two receiving units of a patch antenna system, and shifts the phase by the line length of a received wave transmission line, FIG. 2 is a schematic configuration diagram of the back surface of FIG. 2, FIG. 4 is a schematic configuration diagram of the front surface of a sensor device that has two receiving portions of the patch antenna type and changes the position of the signal conversion portion to shift the phase, and FIG. Schematic configuration diagram, FIG.
The surface of the sensor device having one receiving section of the patch antenna type and shifting the phase by the reception wave transmission path length.
FIG. 7 shows a schematic configuration diagram of a surface of a sensor device having one receiving section of the patch antenna type and changing the position of the signal converting section to shift the phase, and FIG. 8 shows a plurality of distances holding arbitrary output levels. FIG. 9, FIG. 9 is a distance-output level diagram of the sensor device output signal of FIGS. 2 and 3, and FIG. 10 is a distance-output level diagram of the output signal of FIG.
FIG. 9 is a distance-output level diagram in which the maximum value of the output signal is extracted in FIG. 9, and FIG. 12 is a schematic configuration diagram of the signal processing means and the determination unit.
3 is a schematic configuration diagram of a filter circuit, FIG. 14 is a schematic configuration diagram of an offset voltage adjusting mechanism, FIG. 15 is a flowchart for determining a state of a detection target, FIG. 16 is a detection target detection flow chart, and FIG. 17 is two receptions by a patch antenna type. 18 is a schematic front view of a sensor device having a section, FIG. 18 is a schematic back view of a sensor device using two phase difference generating means in combination, and FIG. 19 is a schematic back view of a sensor device in which the phase is shifted by the transmission wave transmission path length. FIG. 20 is a schematic rear view of a sensor device using two phase difference generating means in combination, and FIGS. 21 and 22 are schematic front view of a sensor device having a patch antenna type reception unit and a branching point. FIG. 25 is a schematic configuration diagram of a sensor device having one patch antenna type reception unit and a branch point provided on the back surface, and FIG. 24 is a distance detection flowchart of the detection target.

FIG. 1 shows a schematic configuration diagram in which a signal processing unit 6 and a determination unit 7 are connected to a sensor device. The sensor device 4 transmits the transmission signal 2 to the detection target 1 and receives the reflected reception signal 3
And a signal processing unit 6 that outputs an output signal 5 having different phase differences output from the phase difference generating means 9 in the sensor device 4 and processes the output signal 5. , And a determination unit 8 that compares the detection signal 7 from the signal processing unit 6 with a threshold level to determine the presence or absence of a detection target. In this embodiment, the phase difference generating means 9 for shifting the phase of the output signal 5 by the sensor device 4 is used.
The process of processing the output signal in the signal processing unit 6 will be described.

Here, FIG. 2 shows a schematic diagram of the surface of the sensor device of the patch antenna system. In the present embodiment, the surface on which the transmission unit 11 of the sensor device is located is defined as the front surface. On the front surface, there are a transmission unit 11 that transmits a signal as a radio wave, a transmission wave transmission line 12 that connects the transmission unit 11 and a signal generation unit on the back surface, and a reception signal that the transmission signal is reflected back to an object. Receiving unit 13 for receiving, and receiving unit 13
A reception wave transmission line 14 that sends the reception signal received in
The GND terminal 16 which is the GND of the entire substrate 15 is connected to the substrate 1.
5 above. Further, in order to connect the front surface and the back surface, a through hole 17 which is a small hole is opened on the substrate 15, and the front surface and the back surface are electrically connected by this small hole.

In operation, the transmission signal transmitted from the transmission unit 11 is reflected by the object, received by the reception unit 13, and sent to the back surface through the reception wave transmission path 14. Here, in FIG. 2, the reason why the transmitting unit 11 is configured with two patch antennas is that a plurality of antennas are installed in order to obtain power during transmission. However,
The line length of the transmission wave transmission line 12 is made uniform so as not to shift the phase of the transmission signal transmitted from the antenna.

Further, in the present embodiment, the method of shifting the phase of the received signal by the line length of the received wave transmission line 14 is adopted, but here, the method of shifting the phase by changing the line length on the back surface is adopted. Therefore, the line length of the reception wave transmission line 14 on the surface is made uniform.

Further, FIG. 3 shows a schematic configuration diagram of the back surface of FIG. On the back side, a signal generation means 21 for generating a transmission signal and a transmission wave transmission line 22 for transmitting the transmission signal to the transmission unit 11.
And a received wave transmission line 23 for transmitting a received signal from the surface,
The transmission wave transmission path 22 and the reception wave transmission path 23 are close to each other, and a signal conversion unit 24 for signal processing the reception wave and an output stage 25 for outputting a signal to the outside are provided.

Here, as an operation, on the transmitting side, the signal generating means 21 connected to the power supply 26 generates a transmission signal in an arbitrary frequency band, passes through the transmission wave transmission path 22, and is transmitted from the through hole 17 to the surface. Is transmitted to. On the receiving side, the reception signal is transmitted from the surface through the through hole 17, reaches the signal conversion section 24 through the reception wave transmission path 23, and is converted from high frequency to low frequency by the signal conversion section 24 to be received. It passes through the wave transmission path 28 and is output from the output stage 25.

Here, on the back surface, the received wave transmission line 23
Since the line length differs depending on each receiving unit 13, 2
The received signals of the two receivers have different phases. In the present embodiment, since there are two patch antennas in the receiving unit 13, the phase of each of the two output signals at this time is λ / 4 (90).
It is desirable to determine the length of the reception wave transmission line 23 so that they are deviated from each other (described later).

In the signal converter 24, the high frequency signal transmitted through the reception wave transmission line 23 is transmitted to the transmission wave transmission line 2
2 becomes the low frequency by taking the difference from the signal of 2.
4 is provided with a signal conversion circuit 27 for taking a difference between high frequencies and outputting a low frequency signal derived from the difference. The signal conversion circuit 27 is composed of two diodes and one resistor.

In this embodiment, the method of extracting the low frequency output signal by bringing the transmission wave transmission line and the reception wave transmission line close to each other has been shown. However, other than that, the transmission wave transmission line and the reception wave transmission line are transmitted. There is also a configuration for directly coupling with a path or a configuration for coupling via an electronic component, and in that case, the configuration of the signal conversion circuit is different from the description here (described later).

Here, since the output signal is converted from the high frequency to the low frequency in the signal conversion section 24, the received wave transmission line 28
Is not related to the phase shift, the length of the reception wave transmission line 28 can be set without particular limitation except that the line length is not set to be very long. In this embodiment,
The transmission signal is performed at a high frequency near 10 GHz, and when the detection object is a human body, the signal obtained from the human body is several H.
Since it is a low frequency from z to several hundred Hz, it can be said that the line length has an effect on a high frequency having a short wavelength, but has no effect on a low frequency having a long wavelength.

Here, FIG. 4 shows a schematic diagram of the surface of the sensor device in which the phase is shifted by changing the position of the signal conversion unit. At this time, the front surface has almost the same configuration as that of FIG. 2 described above, but the installation location of the through hole 17 transmitted from the reception wave transmission path 14 to the back surface is changed to be vertically symmetrical. However, the length of the received wave transmission line here is fixed.

Next, FIG. 5 shows a schematic diagram of the back surface of FIG. Here, it is almost the same as the constituent elements of FIG. 3, but unlike FIG. 3, the line length of the received wave transmission line 23 is set to be constant. Here, in FIG. 5, a phase shift is caused by changing the location where the reception wave transmission path 23 and the transmission wave transmission path 22 approach each other in the signal conversion section 24, and there are two reception sections 11. Therefore, here, as will be described later, the phase difference between the two output signals is λ / 4 (9
The position of the signal conversion unit 24 is determined so as to be 0 degree).

Next, the front surface and the back surface of the sensor device for generating the phase difference by changing the place where the transmission wave transmission line and the reception wave transmission line are brought close to each other and changing the length of the reception wave transmission line are shown. Shown at 17, 18. 17 is similar to FIGS. 2 and 4 in that it includes a transmitter 80 including two patch antennas.
And a receiver 81. Here, FIGS.
The GND surface between the transmitting unit and the receiving unit, which is configured by, is omitted for the downsizing of the sensor device.
Is the same as. The operation of the front surface is such that the transmission signal is transmitted by the transmission unit 80, the reflected reception signal is received by the reception unit 81, and is transmitted to the back surface through the through hole 83.

FIG. 18 shows a schematic rear view of FIG.
Here, the phase difference is obtained by changing the approaching locations of the transmission wave transmission line 91 and the reception wave transmission lines 92 and 93 in the signal conversion unit 90 and making the lengths of the reception wave transmission lines 92 and 93 different from each other. Is caused. By using two phase difference generating means together, even when it is necessary to take a large phase difference, it is possible to secure at least the phase difference in the amount of change by simultaneously changing the two.

Further, FIG. 19 shows a schematic rear view of a sensor device for generating a phase difference by changing the length of the transmission wave transmission line of the signal conversion section. The surface at this time is shown in FIG. Here, the signal conversion unit 100 employs a method of directly connecting the transmission wave transmission line 101 and the reception wave transmission line 102 or by connecting them via a signal conversion circuit 103 or the like which is an electronic component. In this embodiment, the signal conversion circuit 10 at this time is
Reference numeral 3 is a Schottky barrier diode, and one having a low capacitance is used. By making the lengths from the branch point 104 on the transmission wave transmission line 101 to the signal conversion unit 100 different from each other, a phase difference occurs in the transmission signal 105, and this phase difference also causes a phase difference in the output signal 106. Is caused.

Further, FIG. 20 shows a schematic rear view of a sensor device for generating a phase difference by changing the lengths of the transmission wave transmission line and the reception wave transmission line. The surface at this time is shown in FIG.
Is. The signal conversion unit 110 also has the same configuration as that of FIG. 19, but since the phase difference is generated in both the lengths of the transmission wave transmission line 111 and the reception wave transmission line 112, the change amount of the length is At least the phase difference can be secured.

Further, FIGS. 6 and 7 show schematic surface diagrams of a sensor device having one patch antenna as a receiving portion. Here, the schematic configuration diagrams of the back surfaces in FIGS.
Since this is the same as in FIGS. 3 and 5, the schematic drawing of the back surface is not shown here. Here, in the case where the receiving unit 31 has one plane pattern, in order to configure one reception wave transmission line 32 into a plurality of reception wave transmission lines, that is, a branch transmission line 33, a branch point 34 is provided and It is configured to be divided into the branch transmission lines 33 and connected to the rear surface. Although not shown in this embodiment, there is no problem in providing a branch point on the back surface, but it is provided on the front surface in this embodiment.

As to the operation on the rear surface, as described above, the operation of FIG. 6 is the same as that of FIG. 3 and the operation of FIG. 7 is the same as that of FIG. 5, and the phase of the output signal can be shifted. Also,
Also in FIGS. 6 and 7, the branch transmission line 33 after the branch point 34
, The output signal has a phase shift of λ
/ 4 (90 degrees) is considered appropriate.

Next, in a sensor device having one patch antenna as a receiving part, a sensor device for generating a phase difference by changing the length of the reception wave transmission line and the approaching positions of the transmission wave transmission line and the reception wave transmission line Figure 21 or 22 for the front side and Figure 18 for the back side
Shown in. Although the operation of the back surface has been described above, similar reception signals can be obtained in FIGS. 21 and 22 for the front surface, but the directional characteristics of the sensor device are changed by changing the pattern of the antenna. .

Further, in a sensor device having one patch antenna as a receiving part, a sensor device which causes a phase difference in the transmission wave transmission line and a sensor device which causes a phase difference in the transmission wave transmission line and the reception wave transmission line are , The front side is FIG. 21 or 22, the back side is FIG. 19, and the front side is FIG. 21 or 22 and the back side is FIG.
Becomes The operation on the back surface is the same as the operation for the two patch antennas described above.

FIG. 23 shows a sensor device having a branch point on the back surface. Here, the phase difference is generated by changing the length of the transmission wave transmission path. The branch point does not affect the operation of the sensor device itself on the front surface or the back surface, but it is possible to save space depending on the substrate space of the sensor device.

In this way, the method of branching with one receiving section can save space due to the size of the substrate becoming smaller when the microwave band is used, and improve the accuracy of stationary detection. Because it can be done, it is considered a very friendly method.

Next, the process of processing the output signal 5 in the signal processing section 6 subsequent to the sensor device 4 will be described.
Here, it is assumed that the sensor device 4 described above is used to generate a phase difference in the output signals. Here, the reason why such processing is performed is that the output with respect to the distance is not uniquely determined even if the output level of the output signal is used as it is, and a large number of the same voltage level points 45 at completely different distances with respect to an arbitrary output value. Is present (see FIG. 8).

FIG. 9 shows the waveforms of the output signals 41 and 42 from the sensor device 4 of FIGS. 2 and 3. Here, the output signals 41 and 42 have a phase difference 43, and the phase difference 43 at this time is λ / 4 of the cycle of the output signals 41 and 42 (the phase difference is 9
The length of the line is determined to be 0 degree). Here, the determination of the phase difference 43 will be described later.

FIG. 10 shows the result of full-wave rectification of the output signals 41 and 42 of FIG. 9 in the signal processing unit 6. Also,
FIG. 11 compares the output signals 41 and 42 subjected to the full-wave rectification for each distance and plots the locus of the maximum value of the distance. According to FIG. 11, linearity between the distance and the output appears in the maximum value extraction locus 44, and the output value with respect to an arbitrary distance can be uniquely shown, but the stationary detection target is also detected. It becomes possible.

Here, as the processing method in the signal processing unit 6 as shown in FIG. 10, there are two methods of full-wave rectification and half-wave rectification.
You can go down the street. However, since half-wave rectification requires an output signal twice as much as full-wave rectification, in the present invention,
Full-wave rectification is performed in consideration of circuit miniaturization and simplification of signal processing. Output signal 4 by performing this full-wave rectification
I made it possible to have linearity by combining the periodic amplitude motions of 1, 42 into one piece.

Further, as the processing after performing the full-wave rectification as described above, there are two possible methods: a method of extracting the maximum value for each distance and a method of adding the maximum value. Here, although there are a maximum value extraction method and an addition method, the waveforms of both methods are the same, but since the absolute value of the output is much larger in the addition, voltage limitation occurs in the signal processing unit 6 in the present invention. Therefore, the maximum value extraction method is performed because it may be used. For example, when a microcomputer is used for the signal processing unit 6, the maximum value voltage may be exceeded when the detection target 1 comes closest to the sensor device 4. Therefore, in such a case, the maximum value extraction method may be used. Seems appropriate.

Here, FIG. 12 shows a schematic processing procedure of the signal processing unit 6 and the judging unit 8 in the present invention. Sensor device 4
The plurality of output signals 5 output from the output stage of 1 are first input to the filter circuit 51 in the signal processing unit 6 for removing noise included in the output signal 5. The filter circuit 51 (FIG. 13) can not only remove noise, but can also be changed depending on what the device incorporating the sensor device of the present invention detects. this is,
Different devices incorporating the sensor device may have different detection targets, or even if the detection targets are the same, the operation may be different, so that various situations can be dealt with.
From FIG. 13, the filter circuit 51 includes an external switch 61 that switches from the outside according to an object to be detected, and a control unit that outputs a signal for changing the resistance value to the variable resistor 62 according to the switching by the external switch 61. 63 and a variable resistor 62 capable of changing the resistance value by receiving a signal from the control unit 63.
It is composed of. In this embodiment, the external switch 61 is capable of selecting several kinds of detection objects and actions in advance, and the control unit 63 changes the resistance value by a microcomputer and the variable resistor 62 changes the resistance value by an external digital signal. A digital potentiometer (AD8402 10KΩ manufactured by Analog Devices) that can be used is used. In response to the switching of the external switch 61, the microcomputer transmits a digital signal to the digital potentiometer, and the resistance value changes according to the signal. By using this filter circuit 51, it is possible to apply an appropriate filter according to several kinds of detection objects and operations.

The output signal passed through the filter circuit 51 is sent to the selector circuit 52 provided in the signal processing section. The selector circuit 52 sequentially selects a plurality of output signals one by one and transmits each output signal 5 to the A / D converter 53.

In the A / D converter 53, the analog signal 54
The output signal 5 which is
The information is transmitted to the information processing circuit 56. This A / D
The digital signal 55 output from the converter 53 is redistributed for each output signal and sent to the full-wave rectification processing unit 57.

In the full-wave rectification processing unit 57, full-wave rectification is performed with the reference voltage as a boundary, and the rectified signal is sent to the maximum value extraction processing means 58. At this time, the offset voltage when the detection target does not exist varies depending on each output signal.Therefore, in order to adjust the offset voltage of each output signal to the preset reference voltage, the offset voltage adjustment is performed in the full-wave rectification processing unit. A mechanism is provided. By providing this mechanism, even if the offset voltage of each output signal is different, it is possible to adjust the offset voltage to a constant value, so that the ratio of the upper and lower sides of the reference voltage does not change due to conversion to full-wave rectification.
In this embodiment, this offset voltage adjusting mechanism is composed of a combination of an operational amplifier 71 and a variable resistor 72, and the variable resistor 72 uses the digital potentiometer also shown above (FIG. 14). This offset voltage adjusting mechanism causes the control unit 73 to monitor the digital signal 55 when there is no object to be detected, and when the digital signal 55 deviates from the reference voltage, the resistance value of the digital potentiometer is changed and held at the reference voltage. It is a thing.

The output signal rectified by the full-wave rectification processing unit 57 is sent to the maximum value extraction means 58. The maximum value extraction means 58 compares each signal sent from each full-wave rectification processing section 57 and sends only the largest value to the next processing means. Maximum value extraction means 5 in this embodiment
No. 8 uses a microcomputer to sample each output signal at a constant cycle and extract the maximum value.

The signal output from the maximum value extraction means 58 is compared with a preset threshold voltage 59 and sent to the comparison / determination means 60 for determining the presence / absence of an object to be detected. The determination processing means here determines the presence or absence of an object to be detected, and finally transmits a signal to the outside.

Next, the operations of the signal processing unit 6 and the judging unit 8 will be shown in a flow chart. FIG. 15 shows a state determination flow for determining whether or not the sensor device detects the detection target, and FIG. 16 shows a detection flow for detecting the detection target. In FIG. 15, the sensor device samples each output signal at a constant cycle (S151), compares each sampled output signal with a set value X for detecting a detection target (S152), and outputs at least 1 When the two output signals exceed the set value X (Yes in S152), the sensor device determines that the detection target has entered the detection range and executes a flow for performing the detection (S15).
3). Further, when the output signal values are all smaller than the set value X, it is determined that there is no detection target object in the detection range of the sensor device (S152 No), and the offset voltage that is the voltage when the detection target object of each output signal value does not exist. Is determined to be the reference voltage Y (S154). Here, if it is the same as the reference voltage Y (S154 Yes), this flow is repeated, and if it is different from the reference voltage Y (S154).
No) The voltage is adjusted by the offset voltage adjusting mechanism described above.

Next, FIG. 16 shows a detection flow performed when the object to be detected enters the detection range in the state determination flow. When the output signal 5 from the sensor device 4 is received, noise is removed from the output signal by the filter circuit in the signal processing unit (S161), and each output signal is converted from an analog signal to a digital signal at regular time intervals. (S162),
Full-wave rectification processing is performed based on the reference voltage controlled to the set value X by the offset voltage adjustment mechanism (S16).
3) Extract the maximum value of each full-wave rectified signal (S1
64), and the presence or absence of the detection target is compared with the threshold value (S165). The threshold value at this time is set according to the device to which the sensor device of the present invention is attached, and the threshold setting is set high when measuring a short distance, and set low when measuring a long distance. is there.

Here, the state determination flow in which the sensor device of the present invention is used as a sensor for detecting the presence or absence of the detection target is described, but it is determined whether or not the detection target is present at the desired distance. The state determination flow of the distance measuring sensor is also shown in FIG. In FIG. 24, the same operation is performed up to S164 of FIG. 16, but a plurality of thresholds according to the distance are set when the maximum value and the threshold are compared, and the set thresholds are in descending order. The comparison is performed to determine how far the detection target is from the sensor device (S241).

By using such a processing means, it becomes possible to apply it to an automatic toilet cleaning device which has conventionally used a photoelectric sensor or the like, or an automatic faucet automatic water discharging device,
Since it can be used as a concealment sensor, it is possible to prevent the sensor from being damaged due to mischief or the like that has conventionally occurred.

In addition, the sensor device 4 shown in this embodiment
Regarding, the output signals are set so that their phases are all different, but as shown above, full-wave rectification is performed,
In the case of performing signal processing for extracting the maximum value, it is possible to reduce the number of points at which the output level drops to 0 by adopting a method in which the phase difference is uniformly generated at regular intervals. If there is a point where the output level drops to 0, the output values will be the same at long distances and short distances, and it will be difficult to determine the presence or absence of the detection target. Therefore, in order to reduce the number of output signals of the sensor device as much as possible and improve the detection accuracy, the phase difference between the output signals is set to (180
It is considered to be optimal to shift at intervals of (° / n) (n:
Number of output signals).

Here, in the present embodiment, an example in which the patch antenna of the planar antenna is used has been given, but the same result can be obtained by using a rod antenna instead of the patch antenna.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a sensor device according to the present invention.

FIG. 2 is a schematic front view of the configuration of a sensor device having two receiving units of a patch antenna system and shifting the phase depending on the line length of a received wave transmission line.

FIG. 3 is a schematic configuration diagram of the back surface of FIG.

FIG. 4 is a schematic surface configuration diagram of a sensor device that has two receiving units of a patch antenna type and changes the position of a signal conversion unit to shift the phase.

5 is a schematic diagram of the back surface of FIG.

FIG. 6 is a schematic configuration diagram of a surface of a sensor device having one receiving unit of a patch antenna type and shifting a phase by a reception wave transmission path length.

FIG. 7 is a schematic surface configuration diagram of a sensor device that has one patch antenna type reception unit and shifts the phase by changing the position of the signal conversion unit.

FIG. 8 is a diagram showing a plurality of distances holding arbitrary output levels.

9 is a distance-output level diagram of the sensor device output signal of FIGS. 2 and 3. FIG.

10 is a distance-output level diagram in which the output signal of FIG. 8 is full-wave rectified by the signal processing unit.

11 is a distance obtained by extracting the maximum value of the output signal of FIG.
Output level diagram

FIG. 12 is a schematic configuration diagram of a signal processing unit and a determination unit.

FIG. 13 is a schematic configuration diagram of a filter circuit.

FIG. 14 is a schematic configuration diagram of an offset voltage adjustment mechanism.

FIG. 15 is a flowchart for determining the state of a detection target object.

FIG. 16 is a flowchart of detection of an object to be detected.

FIG. 17 is a schematic surface configuration diagram of a sensor device having two receiving units of a patch antenna type.

FIG. 18 is a schematic rear view of a sensor device using two phase difference generating means in combination.

FIG. 19 is a schematic rear view of a sensor device that shifts the phase according to the transmission wave transmission path length.

FIG. 20 is a schematic rear view of the sensor male intelligence using two phase difference generating means in combination.

FIG. 21 is a schematic surface configuration diagram of a sensor device having one receiving section and a branch point of a patch antenna type.

FIG. 22 is a schematic surface configuration diagram of a sensor device having one receiving unit and a branch point of a patch antenna type.

FIG. 23 is a schematic configuration diagram of a sensor device having a patch antenna type reception unit and a branch point on the back surface.

FIG. 24 is a distance detection flowchart of a detection target.

[Explanation of reference numerals] 1: detection target object, 2: transmission signal, 3: reception signal, 4: sensor device, 5: output signal, 6: signal processing unit, 7: detection signal, 8: determination unit, 9: position Phase difference generation means, 11: transmission section,
12: transmitted wave transmission line, 13: receiver, 14: received wave transmission line, 15: substrate, 16: GND terminal, 17: through hole, 18: GND line, 21: signal generation means, 22: transmitted wave transmission line , 23: received wave transmission line, 24: signal converter, 2
5: output stage, 26: power supply, 27: signal conversion circuit, 28:
Received wave transmission line, 31: reception unit, 32: received wave transmission line, 3
3: branch transmission line, 34: branch point, 41: output signal 1, 4
2: Output signal 2, 43: Phase difference, 44: Maximum value extraction locus, 45: Same voltage level point, 51: Filter circuit, 52: Selector circuit, 53: A / D converter, 54:
Analog signal, 55: digital signal, 56: information processing circuit, 57: full-wave rectification processing unit, 58: maximum value extraction means,
59: threshold voltage, 60: comparison and determination means, 61: external switch, 62: variable resistor, 63: control unit, 64: capacitor, 71: operational amplifier, 72: variable resistor, 73: control unit, 80: transmission unit , 81: reception unit, 82: transmission wave transmission line, 83: through hole, 91: transmission wave transmission line, 92:
Received wave transmission line, 93: Received wave transmission line, 94: Signal generation means, 95: Transmission signal, 96: Reception signal, 97: Output signal, 98: Signal conversion circuit, 99: Through hole, 10
0: signal converter, 101: transmission wave transmission line, 102: reception wave transmission line, 103: signal conversion circuit, 104: branch point, 1
05: transmission signal, 106: output signal, 107: reception signal, 108: signal generation unit, 109: through hole, 11
0: signal conversion unit, 111: transmission wave transmission line, 112: reception wave transmission line, 113: signal generation unit, 114: branch point, 11
5: signal conversion circuit, 116: transmission signal, 117: reception signal, 118: output signal, 119: through hole, 12
0: transmitter, 121: receiver, 122: branch point, 12
3: Through hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mie Ikushima             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. (72) Inventor Yuichi Furuta             2-1-1 Nakajima, Kokurakita-ku, Kitakyushu City, Fukuoka Prefecture             No. Totoki Equipment Co., Ltd. F-term (reference) 2G005 DA04                 5J070 AC01 AE09 AH14 AH39 AK22

Claims (16)

[Claims] 1. A signal generation means for generating a transmission signal for transmitting a signal as an electric wave to the outside, a transmission section for connecting the signal generation means to the transmission wave transmission line and transmitting the transmission signal to the outside, and A plurality of receiving units that receive a signal received as a radio wave as a receiving signal, and a plurality of signal converters that are connected to the receiving unit by a receiving wave transmission line and extract low-frequency output signals based on each receiving signal and transmitting signal Section, an output stage for outputting the output signal converted by the signal converting section for each receiving section, and a phase difference generating means for generating a phase difference so that the phase difference of the plurality of output signals is different. Full-wave rectification is performed on a sensor device having the sensor device and a plurality of output signals output from each output stage of the sensor device, and a detection signal which is a locus of the maximum value of each full-wave rectified signal is extracted. Belief An object detection device, comprising: a signal processing unit; and a determination unit that detects the presence or absence of an object by comparing the detection signal with a preset threshold that can be set. 2. The object detection device according to claim 1, wherein the phase difference generation means is a reception wave transmission line having a different length from each of the reception units to the signal conversion unit. 3. The phase difference generation means is a signal conversion unit in which the reception wave transmission lines and the transmission wave transmission lines with respect to the reception units approach each other at different positions in order to convert signals. The object detection device according to claim 1, characterized in that 4. The phase difference generating means is a reception wave transmission line having a different length from each of the reception units to the signal conversion unit, and the reception wave transmission to each reception unit for converting a signal. The object detection device according to claim 1, wherein the path and the transmission wave transmission path are signal conversion units that approach each other at different positions. 5. The object detection device according to claim 1, wherein the phase difference generation means is a transmission wave transmission line having different lengths from the signal generation means to the signal conversion section. 6. The phase difference generation means is a reception wave transmission line having a different length from each of the reception sections to the signal conversion section, and has a different length from the signal generation means to the signal conversion section. 2. The object detection device according to claim 1, wherein the object detection device is a transmission wave transmission path of a length. 7. A signal generation means for generating a transmission signal for transmitting the signal as an electric wave to the outside, a transmission section for connecting the signal generation means to the transmission wave transmission line and transmitting the transmission signal to the outside, and A reception unit that receives a signal received as a radio wave as a reception signal, and a plurality of signals that are connected by a reception wave transmission line that is branched from the reception unit and that extracts a low-frequency output signal based on the reception signal and the transmission signal. A sensor device having a conversion unit, an output stage for outputting the output signals converted by the signal conversion unit, and a phase difference generation unit for generating a phase difference so that the phase differences of the plurality of output signals are all different. A signal for performing full-wave rectification on a plurality of output signals output from each output stage of the sensor device at an arbitrary reference voltage and extracting a detection signal which is a locus of the maximum value of each full-wave rectified signal. A management unit, an object detection apparatus characterized by having a decision unit for detecting the presence or absence of an object by performing a comparison with a preset settable threshold with the detection signal. 8. The phase difference generating means is a reception wave transmission line having a different length from a branch point of the reception wave transmission line to each of the signal conversion units. Object detection device. 9. The phase difference generation means is a signal conversion unit in which the reception wave transmission lines and the transmission wave transmission lines with respect to each output stage approach each other at different positions to perform signal conversion. The object detection device according to claim 7, which is characterized in that: 10. The phase difference generation means is a reception wave transmission line having a different length from a branch point of the reception wave transmission line to each of the signal conversion units, and each of the reception wave transmission lines has a different length for performing signal conversion. 8. The object detection device according to claim 7, wherein the reception wave transmission line and the transmission wave transmission line with respect to the output stage are signal conversion units that approach each other at different positions. 11. The object detection device according to claim 7, wherein the phase difference generation means is a transmission wave transmission line having different lengths from the signal generation means to the signal conversion section. 12. The phase difference generation means is a reception wave transmission line having a different length from the branch point to the signal conversion sections, and different lengths from the signal generation means to the signal conversion section. 8. The object detection device according to claim 7, wherein the object detection device is a transmission wave transmission path of a length. 13. The object detecting device according to claim 1, wherein the receiving unit is formed of a columnar antenna. 14. The object detecting device according to claim 1, wherein the receiving unit is formed of a patch antenna formed of a metal film on a flat substrate. 15. The object detection device according to claim 1, wherein the signal processing unit includes a filter circuit that removes unnecessary signals included in the plurality of output signals. 16. The object detecting apparatus according to claim 15, wherein the filter means is a variable filter means capable of changing a frequency band to be transmitted depending on an application.