Piezoelectric rainfall sensor

Abstract

The utility model provides a piezoelectric rainfall sensor, and relates to the technical field of meteorological monitoring. The sensor comprises an insulating bearing plate; a round cover-shaped metal convex surface; the rainwater detection panel is arranged on the upper side face of the insulating bearing plate, surrounds the round-cover-shaped metal protruding face and comprises two conductive circuits arranged in a spaced mode, and windowing processing is conducted on the areas corresponding to the two conductive circuits; a piezoelectric transducer; a rainwater detection circuit; and the MCU is electrically connected with the piezoelectric transducer, and is configured to periodically control the signal control end to be at a high level, detect the level state of the signal output end, and sample the voltage signal generated by the piezoelectric transducer and calculate the rainfall when the level state is at a low level. The sensor can guarantee that piezoelectric signal collection and rainfall calculation are carried out after it is detected that raining starts, interference of bird excrement, sand wind and other environmental factors on the piezoelectric rainfall sensor is reduced, and the measured rainfall is more accurate.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of meteorological monitoring, and particularly relates to a piezoelectric rain sensor. BACKGROUND

[0002] Rainfall, as an important parameter in the field of meteorological monitoring, has important significance for people's life and production decisions. For example, daily travel, agricultural irrigation, and prevention of mountain flood disasters are all affected by rainfall, so the accuracy of rainfall measurement is of great significance to life and production.

[0003] In the related art, the piezoelectric rain sensor utilizes the positive piezoelectric effect of the piezoelectric transducer element to convert the impact of falling raindrops on the sensor sensing surface into an electric charge, and then utilizes a circuit to process the electric charge signal into a pulse signal that varies with the impact force. Finally, the MCU (Microcontroller Unit) measures the rainfall.

[0004] However, due to various environmental factors (such as birds, wind and sand, etc.), the piezoelectric element can be deformed, making it difficult to accurately identify the start of rainfall, thereby causing a large error in rainfall measurement.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. CONTENT OF THE PRESENT DISCLOSURE

[0006] The present disclosure provides a piezoelectric rain sensor, which at least partially overcomes the technical problem of difficulty in accurately identifying the start of rainfall in the related art, thereby causing a large error in rainfall measurement.

[0007] Other characteristics and advantages of the present disclosure will become apparent from the following detailed description, or will be learned by practice of the present disclosure.

[0008] According to one aspect of the present disclosure, a piezoelectric rain sensor is provided, comprising: an insulating load-bearing plate, a circular through-hole being provided in a middle region thereof; a circular cap-shaped metal protruding surface being provided on the circular through-hole and located on an upper side of the insulating load-bearing plate; a rainwater detection panel being provided on the upper side of the insulating load-bearing plate and surrounding the circular cap-shaped metal protruding surface, comprising two conductive circuits being provided with a gap and corresponding regions of the two conductive circuits being windowed; a piezoelectric transducer being provided in a center region of an inner cavity surface of the circular cap-shaped metal protruding surface; a rainwater detection circuit comprising a working voltage output end, a signal control end, a signal output end, a first resistor, a second resistor, a third resistor, and a triode, the working voltage output end being electrically connected to the signal control end and one conductive circuit through the first resistor, and being electrically connected to the signal output end and a collector of the triode through the second resistor, an emitter of the triode being grounded and a base thereof being electrically connected to the other conductive circuit through the third resistor; an MCU being electrically connected to the piezoelectric transducer and being configured to periodically control the signal control end to be at a high level, detect a level state of the signal output end, and sample a voltage signal generated by the piezoelectric transducer and calculate a rainfall amount when the level state is at a low level.

[0009] By configuring the rainwater detection panel and the rainwater detection circuit in the piezoelectric rain sensor, and configuring the MCU to start collecting the piezoelectric signal and calculating the rainfall amount when the signal output end is detected to be at a low level, it can be ensured that the piezoelectric signal is collected and the rainfall amount is calculated after the start of rainfall is detected, and the interference of bird excrement, wind sand and other environmental factors on the piezoelectric rain sensor is reduced, so that the measured rainfall amount is more accurate.

[0010] In some embodiments, the rainwater detection circuit further comprises a capacitor electrically connected to the base and the emitter of the triode.

[0011] By connecting the capacitor in parallel with the base and the emitter of the triode, high-frequency noise in the rainwater detection circuit can be removed, the stability of the signal is ensured, and the accuracy of detecting the start of rainfall is ensured.

[0012] In some embodiments, the rainwater detection circuit further comprises a fourth resistor connected in parallel with the capacitor.

[0013] The fourth resistor connected in parallel with the capacitor can limit the flow of current into other parts of the circuit, protecting the elements from excessive current damage.

[0014] In some embodiments, a circuit through-hole is provided on the insulating load-bearing plate; the two conductive circuits pass through the circuit through-hole and are electrically connected to the first resistor and the third resistor, respectively.

[0015] The two conductive circuits are connected by the line through hole to the first resistor and the third resistor, which can avoid wiring outside the insulating load-bearing plate and avoid the problem that the exposed lines in the piezoelectric rain sensor are easily damaged.

[0016] In some embodiments, the hardware circuit board comprises the MCU and the rain detection circuit; the lower side of the insulating load-bearing plate is provided with a plurality of fixing columns; and the hardware circuit board is arranged on the insulating load-bearing plate through the fixing columns.

[0017] In some embodiments, the gap between the two conductive circuits is within a preset range.

[0018] By limiting the gap between the two conductive circuits within a preset range, the two conductive circuits can be electrically connected after the rain falls between them, and the two conductive circuits can also be easily electrically connected by other factors, thereby improving the accuracy of the start of rainfall identification.

[0019] In some embodiments, the preset range is 0.5-1.2mm.

[0020] In some embodiments, the pre-processing circuit is electrically connected to the piezoelectric transducer and the MCU, respectively, and is configured to amplify, filter and rectify the voltage signal generated by the piezoelectric transducer; the MCU is configured to sample, perform fast Fourier transform, extract the rainfall characteristic frequency spectrum segment using the upper and lower threshold values of the frequency spectrum, calculate the energy integral, and calculate the rainfall amount using the energy integral after detecting the control signal.

[0021] By extracting the rainfall characteristic frequency spectrum segment using the upper and lower threshold values of the frequency spectrum, low-frequency and high-frequency interference caused by environmental factors in the rainfall can be filtered out, so that the measured rainfall amount is more accurate.

[0022] It is understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings herein are incorporated into the specification and form part of the specification, show embodiments consistent with the present disclosure, and together with the specification serve to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 A schematic diagram of a piezoelectric rain sensor in an embodiment of the present disclosure is shown;

[0025] Figure 2 A schematic diagram of a piezoelectric rain sensor according to an embodiment of the present disclosure is shown;

[0026] Figure 3 A schematic diagram of an insulating load-bearing plate according to an embodiment of the present disclosure is shown;

[0027] Figure 4 A schematic diagram of a rainwater detection circuit according to an embodiment of the present disclosure is shown;

[0028] Figure 5 A schematic diagram of another rainwater detection circuit in an embodiment of this disclosure is shown;

[0029] Figure 6 A schematic diagram of another rainwater detection circuit in an embodiment of this disclosure is shown. Detailed Implementation

[0030] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0031] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0032] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the piezoelectric rain sensor in this embodiment includes: an insulating load-bearing plate 1, a round metal protrusion 2, a rain detection panel 3, a piezoelectric transducer 4, a rain detection circuit, and an MCU.

[0033] The insulating load-bearing plate 1 has a circular through hole 11 in the middle area.

[0034] A round, cap-shaped metal protrusion 2 is provided on the circular through hole 11 and is located on the upper side of the insulating load-bearing plate 1.

[0035] The rainwater detection panel 3 is arranged on the upper side of the insulating load-bearing plate 1 and surrounds the circular cap-shaped metal convex surface 2, and comprises two electrically conductive circuits 31 arranged with gaps, and the corresponding areas of the two electrically conductive circuits 31 are windowed.

[0036] The piezoelectric transducer 4 is arranged in the central area of the inner cavity surface of the circular cap-shaped metal convex surface 2.

[0037] The rainwater detection circuit comprises a working voltage output end 51, a signal control end 52, a signal output end 53, a first resistor 54, a second resistor 55, a third resistor 56, and a triode 57, the working voltage output end 51 is electrically connected with the signal control end 52 and one electrically conductive circuit 31 through the first resistor 54, and is electrically connected with the signal output end 53 and the collector of the triode 57 through the second resistor 55, the emitter of the triode 57 is grounded, and the base is electrically connected with the other electrically conductive circuit 31 through the third resistor 56.

[0038] The MCU is electrically connected with the piezoelectric transducer 4, configured to periodically control the signal control end 52 to be high, detect the level state of the signal output end 53, and sample and calculate the rainfall when the level state is low.

[0039] The base of the triode 57 is connected with one electrically conductive circuit 31 through one interface at the line interface 60, and the working voltage output end 51 is connected with the other electrically conductive circuit 31 through another interface at the line interface 60.

[0040] In the working state, the MCU periodically controls the signal control end 52 to be high, and continuously detects the level state of the signal output end 53 at this time. When the signal control end 52 remains high, if rainwater falls into the gap of the rainwater detection panel, a certain resistance value appears between the two electrically conductive circuits on the rainwater detection panel, then Figure 4 The two terminals can be regarded as being connected with a resistance with a certain value, there is current at the base of the triode 57, the triode 57 is turned on, and a low level can be detected at the signal output end 53, at this time, it is considered that rainfall occurs, so that the start of rainfall is effectively identified and external interference is excluded.

[0041] When rainfall occurs, the falling raindrops strike the top circular cap-shaped metal convex surface 2 and generate vibration, the vibration is conducted to the piezoelectric transducer 4, based on the principle of positive piezoelectric effect, the piezoelectric transducer 4 converts the vibration signal into a voltage signal, which is sent to the MCU for processing to calculate the rainfall.

[0042] By configuring the rainwater detection panel and the rainwater detection circuit in the piezoelectric rain sensor, and configuring the MCU to start collecting the piezoelectric signal and calculating the rainfall amount when the signal output end is detected to be low, the piezoelectric signal collection and rainfall calculation can be started after the start of rainfall is detected, the interference of bird excrement, wind sand and other environmental factors on the piezoelectric rain sensor is reduced, and the measured rainfall amount is more accurate.

[0043] In one embodiment, as shown in Figure 5 The rainwater detection circuit further includes a capacitor 58 electrically connected to the base and the emitter of the triode 57.

[0044] By connecting the capacitor in parallel to the base and the emitter of the triode, high-frequency noise in the rainwater detection circuit can be removed, the stability of the signal is ensured, and the accuracy of detecting the start of rainfall is ensured.

[0045] In one embodiment, as shown in Figure 6 The rainwater detection circuit further includes a fourth resistor 59 connected in parallel to the capacitor 58.

[0046] The fourth resistor connected in parallel to the capacitor can limit the current flowing into other parts of the circuit, and protect the elements from excessive current damage.

[0047] In one embodiment, the insulating load-bearing plate 1 is provided with a line through hole 12.

[0048] The two conductive circuits 31 pass through the line through hole 12 and are electrically connected to the first resistor 54 and the third resistor 56, respectively.

[0049] The two conductive circuits connect the first resistor and the third resistor through the line through hole, which can avoid wiring on the outside of the insulating load-bearing plate, and avoid the problem that the piezoelectric rain sensor has more exposed lines and is prone to damage.

[0050] In one embodiment, the piezoelectric rain sensor further includes: a hardware circuit board including the MCU and the rainwater detection circuit.

[0051] The lower side of the insulating load-bearing plate 1 is provided with a plurality of fixing columns 13.

[0052] The hardware circuit board is arranged on the insulating load-bearing plate 1 through the plurality of fixing columns 13.

[0053] In one embodiment, the gap between the two conductive circuits 31 is within a predetermined range.

[0054] By limiting the gap between the two conductive circuits within a preset range, the two conductive circuits can be electrically connected after rain falls between them, and the two conductive circuits can be easily electrically connected by other factors, thereby improving the accuracy of rainfall start recognition.

[0055] The specific value of the preset range is not limited in the embodiments of the present application.

[0056] In one embodiment, the preset range is 0.5-1.2mm.

[0057] In one embodiment, the piezoelectric rain sensor further comprises a preprocessing circuit electrically connected to the piezoelectric transducer 4 and the MCU, configured to amplify, filter and rectify the voltage signal generated by the piezoelectric transducer 4.

[0058] The MCU is configured to sample, perform fast Fourier transform, extract a rainfall characteristic frequency spectrum segment using upper and lower threshold values of the frequency spectrum and calculate an energy integral, and calculate the rainfall amount using the energy integral after processing the voltage signal by the preprocessing circuit.

[0059] The way of extracting the rainfall characteristic frequency spectrum segment using upper and lower threshold values of the frequency spectrum can filter out low and high frequency interference caused by environmental factors in the rain, so that the measured rainfall amount is more accurate.

[0060] Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon considering the specification and practice of the present application disclosed herein. The present disclosure is intended to cover any variations, uses or adaptive changes of the present disclosure following the general principles of the present disclosure and including common knowledge or conventional technical means in the art which are not disclosed by the present disclosure. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A piezoelectric rain sensor, characterized in that, include: An insulating load-bearing plate (1) has a circular through hole (11) in the middle area; A round, cap-shaped metal protrusion (2) is provided on the circular through hole (11) and located on the upper side of the insulating load-bearing plate (1); Rainwater detection panel (3) is set on the upper side of the insulating load-bearing plate (1) and surrounds the round metal protrusion (2), including two conductive circuits (31) with gaps, and the area corresponding to the two conductive circuits (31) is made open window. A piezoelectric transducer (4) is disposed in the central region of the inner cavity surface of the dome-shaped metal protrusion (2); The rain detection circuit includes a working voltage output terminal (51), a signal control terminal (52), a signal output terminal (53), a first resistor (54), a second resistor (55), a third resistor (56), and a transistor (57). The working voltage output terminal (51) is electrically connected to the signal control terminal (52) and a conductive circuit (31) through the first resistor (54), and is electrically connected to the signal output terminal (53) and the collector of the transistor (57) through the second resistor (55). The emitter of the transistor (57) is grounded, and the base is electrically connected to another conductive circuit (31) through the third resistor (56). The microcontroller (MCU) is electrically connected to the piezoelectric transducer (4) and is configured to periodically control the signal control terminal (52) to a high level, detect the level state of the signal output terminal (53), and sample the voltage signal generated by the piezoelectric transducer (4) and calculate the rainfall when the level state is low.

2. The piezoelectric rain sensor according to claim 1, characterized in that, The rainwater detection circuit also includes a capacitor (58) whose two ends are electrically connected to the base and emitter of the transistor (57), respectively.

3. The piezoelectric rain sensor according to claim 2, characterized in that, The rainwater detection circuit also includes a fourth resistor (59) connected in parallel with the capacitor (58).

4. The piezoelectric rain sensor according to claim 1, characterized in that, The insulating load-bearing plate (1) is provided with a circuit through hole (12); The two conductive circuits (31) pass through the line through-hole (12) and are electrically connected to the first resistor (54) and the third resistor (56) respectively.

5. The piezoelectric rain sensor according to claim 1, characterized in that, Also includes: The hardware circuit board includes the MCU and the rain detection circuit; Multiple fixing posts (13) are provided on the lower side of the insulating load-bearing plate (1); The hardware circuit board is mounted on the insulating load-bearing plate (1) via the plurality of fixing posts (13).

6. The piezoelectric rain sensor according to claim 1, characterized in that, The gap between the two conductive circuits (31) is within a preset range.

7. The piezoelectric rain sensor according to claim 6, characterized in that, The preset range is 0.5-1.2mm.

8. The piezoelectric rain sensor according to claim 1, characterized in that, Also includes: The preprocessing circuit is electrically connected to the piezoelectric transducer (4) and the MCU respectively, and is configured to amplify, filter and rectify the voltage signal generated by the piezoelectric transducer (4); The MCU is configured to sample the voltage signal processed by the preprocessing circuit, perform a fast Fourier transform, extract the rainfall characteristic spectrum segment using the upper and lower limit thresholds of the spectrum and calculate the energy integral, and calculate the rainfall using the energy integral after detecting the control signal.

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