JP2003084076A - Detector, system and method for detecting rainfall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a start of rainfall serving as a trigger, for example, for an alarm in taking-in of washing and for an operation of a wiper in a vehicle, is not detected, since an amount of rainfall in an extent capable of collecting rain water is enough to be detected in a conventional rainfall detector/rainfall system and a all detecting sensor. SOLUTION: This system is provided with a micro strip antenna formed on a plane or curved-face dielectric substrate, an oscillator for supplying an RF signal to the micro strip antenna, a circulator connected to an intermediate between the micro strip antenna and the oscillator to branch reflected electric power from the micro strip antenna, a detector for converting the reflected electric power branched by the circulator into a voltage, and a comparator for comparing the voltage from the detector with a prescribed value for detecting a rainfall condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rainfall detection device, a rainfall detection system and a rainfall detection method for detecting the start of rain.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, Japanese Patent Laid-Open No. 2000-2925.
It is a figure which shows the rainfall detection apparatus described in 54, and FIG. 8 is a figure which shows a rainfall detection sensor. In the figure, 1 is a funnel,
2 is a tipping box, 3 is a rainfall detection sensor, 4 is a wire mesh, 5 is a filtering material, 6 is an intermediate funnel, 7 is a support, 8 is a water receiving part, 9 is a rotating shaft, 10 is a water receiving tray, 11 is a light. Fiber, 12 bend imparting part, 13 case, 14 drainage hole, 15 spring, 16 upper bend adapter, 17 lower bend adapter, 18 guide, 19 fixing bolt, 20 spring, 21 roller. is there.

Next, the operation of the conventional rainfall detecting device will be described. The rainwater received by the funnel 1 as the rainfall occurs is stored in the tipping box 2. The tipping box 2 includes a pair of water receiving portions 8 mounted on a support 7 so as to be swingable. The water receiving parts 8 are located on both sides of the rotary shaft 9, and the intermediate funnel 6
One of the water receiving parts 8 receives the rainwater from. One water receiving part 8
When is full, the water receiving portion 8 is swung downward by its weight, and the rainwater stored in one water receiving portion 8 is drained. In this way, when the stored rainwater becomes large, it falls, and the rainwater drained along with this fall is received by the water receiving tray 10 in the rainfall detection sensor 3. The water receiving tray 10 becomes heavier due to the entry of rainwater, and the upper bending adapter 1 is connected via the spring 15.
It operates so as to push down 6 and functions to bend the optical fiber 11 sandwiched between it and the lower bending adapter 17.

During normal times when there is no rainwater in the water receiving tray 10, the space between the upper bending adapter 16 and the lower bending adapter 17 is open, and the optical fiber 11 is held in a straight line. Due to the weight of the stored rainwater, the sandwiched optical fiber 11 bends to increase the transmission loss.

This optical fiber is provided with an E / O, an O / E device or an OTDR (Optical) which outputs a contact signal.
TimeDomain Reflectometer)
Is connected, and a contact signal is output from the E / O or O / E device based on the decrease in light intensity due to the increase in transmission loss,
The point where the transmission loss increases is detected by OTDR.

[0006]

In the above-mentioned rainfall detecting device and rainfall detecting sensor, the amount of rainfall cannot be detected unless the amount of rainfall is such that rainwater accumulates, for example, an alarm for taking in laundry or a car wiper. There is a problem that it is not possible to detect the start of rain which is a trigger for operating the.

The present invention has been made in order to solve the above-mentioned problems, and it is a rain detecting apparatus and a rain detecting system capable of detecting a state in which a small amount of raindrops are attached such as when it starts to rain. , And a method for detecting rainfall.

[0008]

A rainfall detecting device according to a first aspect of the present invention includes a microstrip antenna formed on a dielectric substrate, an oscillator for supplying an RF signal to the microstrip antenna, a microstrip antenna and an oscillator. A circulator that connects the reflected power from the microstrip antenna, and a detector that converts the reflected power that is branched by the circulator into a voltage, and a predetermined default value that detects the voltage from the detector and the rainfall condition. And a comparator for comparing.

In the rainfall detecting device of the second invention, the comparator of the first invention can arbitrarily set and change the level of a predetermined predetermined value for detecting the rainfall condition from an external system of the rainfall detecting device or inside thereof. It is equipped with means.

The rainfall detection system of the third invention comprises a plurality of rainfall detection apparatuses of the first invention or the second invention, and compares or adds output signals from respective comparators of the plurality of rainfall detection apparatuses. It is equipped with a distribution detection device.

The rainfall detection system of the fourth invention comprises a microstrip array antenna having a plurality of microstrip antennas, a feeding circuit for distributing an RF signal to the microstrip array antenna, and an RF signal to the microstrip array antenna. An oscillator, a circulator that is connected between the microstrip array antenna and the oscillator to branch the reflected power from the microstrip array antenna, a detector that converts the reflected power branched by the circulator into a voltage, and a voltage from the detector. And a comparator for comparing a predetermined default value for detecting the rainfall situation.

According to the rainfall detection system of the fifth aspect of the invention, the comparator of the fourth aspect of the invention can arbitrarily change the level setting of a predetermined predetermined value for detecting the rainfall condition from an external system of the rainfall detection system or inside. It is equipped with means.

A rain detecting method according to a sixth aspect of the present invention is a method for detecting a rain condition by changing a level of reflection loss of a microstrip antenna.

A rain detecting method according to a seventh aspect of the present invention is a method for detecting a rain condition by using the rain detecting apparatus according to the first aspect or the second aspect of the invention, by changing the level of the reflection loss of the microstrip antenna.

A rainfall detecting method according to an eighth aspect of the present invention detects the rainfall situation by comparing or adding output signals from respective comparators of a plurality of rainfall detecting devices using the rainfall detecting system of the third aspect. Is the way.

The rainfall detecting method of the ninth invention is a method of detecting the rainfall situation by changing the level of the reflection loss of the microstrip array antenna, using the rainfall detecting system of the fourth invention or the fifth invention. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a cross-sectional view of a rainfall detection device that is Embodiment 1 of the present invention. In the figure, reference numeral 22 is a dielectric substrate, 23 is a microstrip antenna, 24 is a circulator, 25 is an oscillator, 26 is a detector, 27 is a comparator, and 28 is a rainfall detection device according to the first embodiment of the present invention. is there. 2 is a view of the microstrip antenna 23 viewed from above, and 29 in the drawing is a raindrop attached to the dielectric substrate 22.

Next, the operation will be described. The relationship between the dimensions L and W of the microstrip antenna 23, the relative permittivity ε _{r of the} dielectric substrate 1 and the resonance wavelength λ ₀ is expressed by Equation 1. Further, the relationship between the resonance frequency _fr and the resonance wavelength λ ₀ is expressed by Equation 2. Here, C represents the speed of light.

[0019]

[Equation 1]

[0020]

[Equation 2]

Therefore, when the raindrop 29 is not present on the microstrip antenna 23, when the RF signal of the frequency shown by the equations 1 and 2 is transmitted from the oscillator 25,
The signal is supplied to the microstrip antenna 23 via the circulator 24, and most of the power is radiated into space.

Next, consider a case where at least a part of the raindrop 29 adheres to the microstrip antenna 23.
The microstrip antenna 23 can be considered as a matching device that matches the impedance of the circuit with the impedance of the space. Here, if at least a part of the raindrop 29 adheres to the microstrip antenna 23, it is equivalent to a pseudo change in the impedance of the space, so that the resonance frequency of the microstrip antenna 23 changes.

FIG. 3 shows an example of change data of the resonance frequency by an experiment. In the figure, the line A shows the reflection characteristic without raindrops, and the line B shows the reflection characteristic with raindrops.
The C line shows the resonance frequency in the absence of raindrops, which is made equal to the frequency of the RF signal sent from the oscillator 25. When the raindrops 29 adhere, the reflection characteristics of the microstrip antenna 23 change and
The reflected power for the RF signal having a frequency equal to the resonance frequency of the microstrip antenna 23 when the raindrop 29 sent from the oscillator 25 does not exist increases, and in the experimental data according to FIG. 3, the reflection loss level is about 19 dB ( 80 times).

The RF signal fed to the microstrip antenna 23 whose resonance frequency has changed is reflected and returned to the circulator 24. The circulator 24 outputs the reflected signal to a port different from the oscillator 25 and injects the reflected signal into the connected detector 26. In the detector 2, the output voltage changes according to the level of the reflected signal.

The output voltage, which changes according to the level of the reflected signal output from the detector 26, is input to the comparator 27. The comparator 27 compares it with a threshold value for rainfall detection which is held inside beforehand, and outputs a rainfall detection signal Da when a voltage exceeding the threshold value is input. Further, the threshold value for rainfall detection, which is held inside in advance, may be capable of arbitrarily changing the level setting, for example, according to the responsiveness of the purpose of use of rainfall detection. That is, in the case of an application purpose in which immediate notification is required even with a very small amount of rainfall, the detection sensitivity is increased by setting a low level threshold value. Similarly, it goes without saying that this threshold can be arbitrarily set and changed by an external system.

The influence of raindrops on the microstrip antenna 23 increases in proportion to the ratio of the area of the raindrops to the area of the microstrip antenna 23. By appropriately designing the dimensions of the antenna 23 together, it is possible to improve the detection accuracy for raindrops to be observed. For example, in the case of heavy rain such as thunderstorm, the spread of raindrops is several tens of millimeters, so a microstrip antenna operating in the X band band is sufficient, but when detecting fine raindrops such as drizzle, Ka is used. It is more effective to use a small size microstrip antenna that operates in the band range.

This rainfall detection signal can be used, for example, as a wiper drive signal for an automobile or as a warning signal for starting rainfall.

As described above, the rainfall detecting apparatus according to the first embodiment can detect the presence or absence of even small raindrops of about several mm / hour, and thus can detect the beginning of rain. It will be possible.

Embodiment 2. FIG. 4 is a diagram showing a second embodiment of the present invention. In the figure, 28A is a rain detector array in which a plurality of rain detectors 28 are arranged,
Is a distribution detection device to which each rainfall detection signal from the rainfall detection device array 28A is input. FIG. 5 is a configuration diagram showing the inside of the distribution detection device 30, 31 is a logical sum operator for obtaining the logical sum of a plurality of rainfall detection signals, and 32 is a counter for obtaining the number of rainfall detection signals being output. Is. The operation of the rainfall detection device 28 is the same as that of the first embodiment.

Next, the operation will be described. The rainfall detection signals (D) output from the rainfall detection device array 28A.
, D2, D3, D4, ..., Dn, hereinafter referred to as Dn) are input to the distribution detection device 30. In the distribution detection device 30, the rain detection device array 28A
The logical sum of the rainfall detection signals Dn generated from the above is obtained, and the number of the rainfall detection devices 28 outputting the rainfall detection signals Db is obtained by the counter 32. Further, the threshold value for rainfall detection, which is held inside in advance, may be capable of arbitrarily changing the level setting, for example, according to the responsiveness of the purpose of use of rainfall detection. That is, in the case of an application purpose in which immediate notification is required even with a very small amount of rainfall, the detection sensitivity is increased by setting a low level threshold value. Similarly, it goes without saying that this threshold can be arbitrarily set and changed by an external system.

The rainfall detection signal Db obtained by the logical sum detector 31 is output to the microstrip antenna 23 because the rainfall detection signal Db is output when even one of the rainfall detection device arrays 28A detects the rainfall. The probability of raindrop attachment is increased, and it becomes possible to detect the start of rain earlier.

Further, since the signal obtained by the counter 32 is the ratio of the rainfall detection device array 28A that has detected the rainfall, the amount of rainfall (heavy rain, light rain,
It can be used as a signal for judging whether it is drizzle or the like, that is, the rainfall intensity signal S. For example, of the 100 rainfall detection devices 28, 50 rainfall detection devices 28 output the rainfall detection signals Db, and 100 rainfall detection devices 2
Rain detection signals Db from five of the eight rain detection devices 28
The area where the raindrops are attached is 10 times different from the case where is generated, which indicates the degree of rainfall.

Embodiment 3. FIG. 6 is a diagram showing a third embodiment of the present invention. In the figure, 23A is a microstrip array antenna in which a plurality of microstrip antennas 23 are arranged in an array, and 33 is a feeding circuit for feeding power to the microstrip array antenna 23A. The RF signal from the oscillator 25 is supplied to the circulator 24.
Is input to the power feeding circuit 33 via the power feeding circuit 33, is distributed in the power feeding circuit 33, and is radiated into space from the microstrip array antenna 23A. Here, similarly to the operation in which the raindrop 29 adheres to the microstrip array antenna 23A and its reflection characteristic changes, when the raindrop 29 adheres to the microstrip array antenna 23A, the reflection characteristic seen from the input of the feeding circuit 33 is Change. In addition, the threshold value for rainfall detection, which is held in advance inside, may be set and changed arbitrarily, and further, this threshold value may be set and changed by an external system. is there.

As described above, even if the microstrip array antenna 23A and the power feeding circuit 33 are combined, it is possible to detect the presence or absence of raindrops as in the rainfall detecting apparatus according to the first embodiment. The area range can be expanded. Further, the microstrip antennas 23 constituting the microstrip array antenna 23A do not need to be regularly arranged, and may be arranged at random or at any position intended for a specific purpose. Absent.

[0035]

According to the first to ninth aspects of the invention, the presence or absence of even a minute raindrop of about several mm / hour can be detected, so that it is possible to detect the beginning of rain. Become.

Further, according to the third, sixth or eighth aspect of the invention, it is possible to improve the probability of detection of the beginning of rain and to determine the degree of rainfall, so-called strength.

Furthermore, according to the fourth, fifth, sixth or ninth invention, the presence or absence of raindrops can be detected, and the array can be arbitrarily expanded by forming an array.

[Brief description of drawings]

FIG. 1 is a rainfall detection device showing a first embodiment of the present invention.

FIG. 2 is a diagram showing the shape of a microstrip antenna and the attachment of raindrops.

FIG. 3 is a diagram showing changes in the reflection characteristics of a microstrip antenna due to the attachment of raindrops.

FIG. 4 is a rainfall detection system showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a distribution detection device of the rainfall detection system showing the second embodiment of the present invention.

FIG. 6 is a diagram showing a distribution detection device of a rainfall detection system showing a third embodiment of the present invention.

FIG. 7 is a diagram showing a conventional rainfall detection device.

FIG. 8 is a diagram showing a rainfall detection sensor used in a conventional rainfall detection device.

[Explanation of symbols]

1 funnel, 2 tipping box, 3 rainfall detection sensor, 4
Wire mesh, 5 filter media, 6 intermediate funnel, 7 support,
8 water receiving part, 9 rotating shaft, 10 water receiving plate, 11
Optical fiber, 12 bending part, 13 case, 1
4 drainage holes, 15 springs, 16 upper bending adapters, 17 lower bending adapters, 18 guides, 1
9 fixing bolts, 20 springs, 21 rollers, 2
2 Dielectric Substrate, 23 Microstrip Antenna, 23A Microstrip Array Antenna, 24
Circulator, 25 oscillator, 26 detector,
27 comparators, 28 rainfall detection device, 28A rainfall detection device array, 29 raindrops, 30 distribution detection device,
31 OR detector, 32 counter, 33 power supply circuit

Claims (9)

[Claims] 1. A microstrip antenna formed on a dielectric substrate, an oscillator for supplying an RF signal to the microstrip antenna, and a connection between the microstrip antenna and the oscillator. A circulator that branches the reflected power of, a detector that converts the reflected power that is branched by the circulator into a voltage, and a comparator that compares the voltage from the detector with a predetermined default value that detects the rainfall condition, A rainfall detection device characterized by being provided. 2. The comparator comprises means for arbitrarily changing the level setting of a predetermined default value for detecting the rainfall condition from an external system of the rainfall detecting device or inside thereof. The rainfall detection device according to 1. 3. A plurality of rainfall detecting devices according to claim 1 or 2, and a distribution detecting device for comparing or adding output signals from respective comparators of the plurality of rainfall detecting devices. Rainfall detection system. 4. A microstrip array antenna including a plurality of the microstrip antennas, a feeding circuit for distributing an RF signal to the microstrip array antenna, an oscillator for supplying an RF signal to the microstrip array antenna, A circulator that is connected between the strip array antenna and the oscillator and branches the reflected power from the microstrip array antenna, a detector that converts the reflected power branched by the circulator into a voltage, and a voltage from the detector. And a comparator for comparing a predetermined default value for detecting a rainfall situation, and a rainfall detection system. 5. The comparator comprises means for arbitrarily changing the level setting of a predetermined default value for detecting a rainfall condition from an external system of the rainfall detection system or inside thereof. The rainfall detection system according to 4. 6. A rainfall detecting method, which detects a rainfall situation by changing a level of reflection loss of a microstrip antenna. 7. A rainfall detecting method, comprising: using the rainfall detecting apparatus according to claim 1 or 2 to detect a rainfall situation by changing a level of reflection loss of a microstrip antenna. 8. The rainfall detection system according to claim 3, wherein the rainfall situation is detected by comparing or adding output signals from respective comparators of a plurality of rainfall detection devices. Method. 9. A rainfall detection method, comprising: using the rainfall detection system according to claim 4 or 5 to detect a rainfall situation by changing a level of reflection loss of a microstrip array antenna.