Rainfall sensor based on multilayer piezoelectric film

Abstract

The invention relates to a rainfall sensor based on a multi-layer piezoelectric film in the field of rain gauges, and the rainfall sensor recognizes the impact characteristics of dust particles through a piezoelectric characteristic recognition module, and monitors the accumulated dust impact through a dust capacity monitoring module. When the real-time time reaches the set maintenance time or the accumulated dust impact amount reaches the set maintenance dust impact amount, a rotating motor and a water pump are started to rotationally wash the impact surface of an impact cover, so that the influence of dust on the measurement precision of the piezoelectric rain gauge is reduced, manual field maintenance is replaced, and the maintenance efficiency and cost performance are improved; meanwhile, through an electromagnetic flow valve and a precision self-checking unit, quantitative clean water is used for simulating natural rainfall, the simulated rainfall measured by a piezoelectric vibrator is compared with the quantitative spraying amount of clean water, the precision of the pluviometer is detected, the precision problem of the pluviometer is found through precision self-checking, and a maintenance requirement is sent out in time through an early warning module.

Description

Technical Field

[0001] The present invention relates to a rainfall sensor, and particularly to a rainfall sensor based on a multi-layer piezoelectric film applied to the field of rain gauges. Background Art

[0002] The multi-layer piezoelectric film rain gauge utilizes the piezoelectric effect to enhance the charge output through a multi-layer PVDF film and improve the measurement sensitivity. When raindrops strike, the film deforms to generate charges, which are converted into rainfall data through signal processing. The multi-layer design not only improves the accuracy but also enhances the anti-interference ability and filters non-rainfall signals.

[0003] During the use of existing piezoelectric rain gauges, their test accuracy is significantly affected by the accumulation of dust on the rain-sensing surface. The dust includes environmental particles that settle naturally and slowly, as well as particulate pollutants that deposit rapidly during sandstorm weather. Both can cause the vibration signals generated when raindrops impact the rain-sensing surface to be distorted. This distortion not only interferes with the accurate measurement of rainfall but also accelerates the aging of the device due to the friction effect. The current maintenance mechanism is passive, that is, it can only be detected after the dust accumulation causes data anomalies, and professional technicians need to be dispatched to the site for cleaning and maintenance, which is time-consuming and costly.

[0004] The patent with the publication number CN220543142U discloses a piezoelectric rainfall sensor bracket, belonging to the technical field of sensors. A piezoelectric rainfall sensor bracket includes a sensor, and a base and an outer cover are sleeved on the outer peripheral side of the sensor. One end face of the outer cover is provided with a water tank, and a toothed ring is rotatably connected to the inner wall of the water tank. A scraping component is installed on the toothed ring; the scraping component includes at least two rotating pins fixed on the end face of the toothed ring, and a scraping rod is sleeved on the rotating pin. After the water tank is filled with rainwater, the present invention can generate a siphon phenomenon through the structure of the siphon tube, impact the water wheel with the water in the water tank, and make the scraping rod rotate on the sensor, so as to clean the surface of the sensor, effectively avoiding obstacles such as withered leaves or clay from blocking the sensor and causing a large error in its measurement results.

[0005] The above-mentioned existing technology uses a hydraulically driven scraping rod to clean the rain-sensing surface of the sensor. However, it adopts a passive maintenance and cleaning method, which requires the accumulation of rainwater for driving. Although the scraping rod cleans the rain-sensing surface during rainy weather, it also affects the normal impact of raindrops on the rain-sensing surface, affecting the normal monitoring of rainfall, and cannot perform active maintenance treatment according to the dust accumulation amount. Summary of the Invention

[0006] Aiming at the above-mentioned existing technology, the technical problem to be solved by the present invention is that the existing rain gauges cannot perform active maintenance and cleaning according to the dust accumulation amount.

[0007] To solve the above problems, the present invention provides a rainfall sensor based on a multi-layer piezoelectric thin film, including a rain gauge body; the rain gauge body includes a housing, an impact cover is fixedly connected to the upper end of the housing, a piezoelectric vibrator is adhesively fixed to the inner wall of the impact cover, the piezoelectric vibrator is made of a multi-layer piezoelectric thin film, and the piezoelectric vibrator is electrically connected to a controller fixed in the housing; An elevating spray pipe for flushing the impact cover is provided outside the housing. The elevating spray pipe includes a rotating pipe, a sliding pipe is slidably connected in the rotating pipe, and the sliding pipe abuts against a spring nested in the rotating pipe; spray holes are formed in the upper part of the sliding pipe and abut against the inner wall of the rotating pipe; a fixed rod is fixedly connected to the outer wall of the rotating pipe, the fixed rod is fixedly connected to a rotating toothed ring rotatably connected to the housing, a driving gear is meshed inside the rotating toothed ring, the driving gear is fixedly connected to the output shaft of a rotating motor, and the rotating motor is fixedly connected in the housing; The lower end of the rotating pipe is fixedly communicated with a linkage pipe, the linkage pipe is rotatably communicated with a rotating sleeve, the rotating sleeve is fixedly connected to the housing, the lower end of the rotating sleeve is fixedly communicated with a liquid outlet pipe, the liquid outlet pipe is fixedly communicated with the output end of a water pump, and the water pump is fixedly connected to the inner wall of the housing; the input end of the water pump is fixedly communicated with a liquid suction pipe, the liquid suction pipe is fixedly communicated with a liquid storage tank, and the liquid storage tank is filled with clean water; The controller is equipped with a maintenance system. The maintenance system includes a control module. The input ends of the control module are respectively connected with a rainfall monitoring module, a dust amount monitoring module, a timing module and a self-check module. The input ends of the rainfall monitoring module and the dust amount monitoring module are both connected to a piezoelectric characteristic identification module, and the input end of the piezoelectric characteristic identification module is connected to the piezoelectric vibrator; the output end of the control module is connected to an execution module, and the output end of the execution module is respectively connected to the rotating motor and the water pump.

[0008] In the above rainfall sensor based on a multi-layer piezoelectric thin film, through the dust amount monitoring module and the timing module, the impact cover is actively flushed and cleaned based on the dust accumulation amount and the set maintenance time.

[0009] As a further improvement of the present application, an electromagnetic flow valve is fixedly connected to the liquid outlet pipe. The electromagnetic flow valve is used to detect the amount of clear water flowing into the elevating spray pipe. The rainfall monitoring module includes a piezoelectric water volume unit and an analog water volume unit. The piezoelectric water volume unit is used to obtain rainfall data measured based on the piezoelectric vibrator, and the analog water volume unit is used to obtain water volume data measured by the electromagnetic flow valve; the self-check module includes a dust self-check unit and an accuracy self-check unit. The dust self-check unit is used to compare the cumulative dust impact amount with the set maintenance dust impact amount, and the accuracy self-check unit is used to compare the rainfall data and the water volume data; the maintenance system further includes a warning module connected to the output end of the control module, and the warning module is used to send a warning instruction to the remote monitoring room.

[0010] As a further improvement of the present application, the housing has a multi-stage frustum-shaped structure, the impact cover has an arc-shaped cover structure, and a collar is fixedly connected to the lower end thereof. The collar is sleeved on the upper part of the housing and fixedly connected to the housing by means of bolts. The diameter of the lower end face of the impact cover is larger than the diameter of the upper end face of the housing. The upper end face of the rotating pipe is flush with the lower end face of the impact cover. After the sliding pipe extends out of the rotating pipe, the spray holes always face the impact surface of the impact cover.

[0011] As a further improvement of the present application, the rotating gear ring has an annular structure, and tooth grooves are provided on the inner wall of its circumference at equal circumferential intervals. An annular groove for the rotation of the rotating gear ring is provided on the housing. An open groove communicating the annular groove and the inner cavity of the housing is provided on the housing, and the driving gear penetrates through the open groove.

[0012] As a further improvement of the present application, the rotating sleeve includes an annular cover fixedly sleeved on the housing and an annular plate rotatably connected to the annular cover. An annular cavity is formed between the annular plate and the annular cover. The linkage pipe is fixedly connected to the annular plate and communicated with the annular cavity.

[0013] As a further improvement of the present application, the controller further includes a communication module, and the communication module is connected to the output end of the warning module.

[0014] As a further improvement of the present application, the maintenance system further includes a foreign object impact monitoring module connected to the input end of the control module. The input end of the foreign object impact monitoring module is connected to the piezoelectric characteristic identification module. The foreign object impact monitoring module is used to monitor the impact force and the number of impacts generated when a foreign object impacts the impact cover.

[0015] As a further improvement of the present application, the following steps are included during use: Step 1, based on the collection of impact vibration signals by the piezoelectric vibrator and the identification of the impact signal category by the piezoelectric characteristic identification module, the rainfall monitoring module and the dust accumulation impact amount monitoring module in the controller monitor the rainfall amount and the dust accumulation impact amount in real time; Step 2, the self-checking module compares the dust accumulation impact amount with the set dust maintenance impact amount. When the dust accumulation impact amount is not less than the set dust maintenance impact amount, the execution module starts the rotating motor and the water pump to rotate and wash the impact surface of the impact cover until the washing time reaches the set washing time, and then the execution module turns off the rotating motor and the water pump; when the dust accumulation impact amount is less than the set dust maintenance impact amount, step 3 is executed; Step 3, when the real-time time reaches the set maintenance time, the execution module starts the rotating motor and the water pump until the washing time reaches the set washing time, and then the execution module turns off the rotating motor and the water pump; when the real-time time does not reach the set maintenance time, no operation is performed.

[0016] As a further improvement of the present application, the following steps are included during accuracy self-check: Step 1: When the dust self-check is completed and the flushing operation is performed, or when the set precision self-check time is reached, start the precision self-check. The precision self-check unit sends a precision test instruction to the execution module, and the execution module starts the rotation motor, water pump, and electromagnetic flow valve to spray a set amount of clean water onto the impact surface of the impact cover for precision testing. Step 2: During the precision test, obtain the test cumulative rainfall data measured based on the piezoelectric vibrator through the piezoelectric water volume unit. The precision self-check unit compares the test cumulative rainfall data with the set amount of the sprayed clean water. When the difference between the test cumulative rainfall data and the set amount of the sprayed clean water is less than the set difference threshold, it is determined that the measurement accuracy of the rain gauge meets the requirements; when the absolute value of the difference between the test cumulative rainfall data and the set amount of the sprayed clean water is not less than the set minimum threshold, it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements. Step 3: When it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements, the warning module sends a warning instruction to the remote monitoring room to notify the operator that the current measurement accuracy of the rain gauge does not meet the requirements and wait for the operator to handle it subsequently.

[0017] In summary, the present invention identifies the impact characteristics of dust particles through the piezoelectric feature recognition module, and monitors the cumulative dust impact amount through the dust amount monitoring module. When either of the two situations occurs, that is, when the real-time time reaches the set maintenance time or the cumulative dust impact amount reaches the set maintenance dust impact amount, start the rotation motor and water pump to rotate and flush the impact surface of the impact cover, reduce the influence of dust on the measurement accuracy of the piezoelectric rain gauge, replace manual on-site maintenance, and improve the maintenance efficiency and cost performance. Description of the Drawings

[0018] Figure 1 is the three-dimensional structure schematic diagram of the present application; Figure 2 is the transverse cross-sectional structure schematic diagram of the present application; Figure 3 is Figure 2 the enlarged structure schematic diagram at A in Figure 4 is the module schematic diagram of the maintenance system in the present application; Figure 5 is the module schematic diagram of the rainfall monitoring module in the present application; Figure 6 is the module schematic diagram of the self-check module in the present application; Figure 7 is the three-dimensional cross-sectional structure schematic diagram of the present application; Figure 8 is the exploded assembly schematic diagram of the housing in the present application; Figure 9Schematic diagram of the state of the lifting nozzle for jet flushing.

[0019] Description of the reference numerals in the figure: 1. Housing; 101. Open trough; 2. Impact cover; 3. Piezoelectric vibrator; 4. Controller; 5. Lifting nozzle; 501. Rotating pipe; 502. Sliding pipe; 5021. Spray hole; 503. Spring; 6. Fixed rod; 7. Rotating gear ring; 8. Driving gear; 9. Rotating motor; 10. Linking pipe; 11. Rotating sleeve; 1101. Ring-shaped cover; 1102. Ring-shaped plate; 12. Liquid outlet pipe; 13. Electromagnetic flow valve; 14. Water pump; 15. Liquid suction pipe; 16. Liquid storage tank; 17. Wind speed sensor; 18. Mounting rod. Specific embodiments

[0020] The following describes two embodiments of the present application in detail with reference to the accompanying drawings.

[0021] The first embodiment: Figure 1-4 And Figure 7-9 A rain sensor based on a multi-layer piezoelectric film is shown, including a rain gauge body; the rain gauge body includes a housing 1, an impact cover 2 is fixedly connected to the upper end of the housing 1, a piezoelectric vibrator 3 is adhesively fixed to the inner wall of the impact cover 2, the piezoelectric vibrator is made of a multi-layer piezoelectric film to improve the recognition efficiency of the vibration characteristics of the impact cover 2, and the piezoelectric vibrator 3 is electrically connected to a controller 4 fixed in the housing 1; Please refer to Figure 3 And Figure 9 , a lifting nozzle 5 for flushing the impact cover 2 is provided outside the housing 1, the lifting nozzle 5 includes a rotating pipe 501, a sliding pipe 502 is slidably connected inside the rotating pipe 501, and the sliding pipe 502 abuts against a spring 503 nested inside the rotating pipe 501; spray holes 5021 that abut against the inner wall of the rotating pipe 501 are formed in the upper part of the sliding pipe 502. When cleaning water is injected into the rotating pipe 501, the sliding pipe 502 is pushed upward, so that the sliding pipe 502 extends above the rotating pipe 501, and the cleaning water sprays out from the spray holes 5021; Please refer to Figure 3 And Figure 9 , a fixed rod 6 is fixedly connected to the outer wall of the rotating pipe 501, the fixed rod 6 is fixedly connected to a rotating gear ring 7 rotatably connected to the housing 1, a driving gear 8 is meshed inside the rotating gear ring 7, the driving gear 8 is fixedly connected to a rotating motor 9 fixed in the housing 1, the rotating motor 9 drives the rotating gear ring 7 to rotate through the driving gear 8, and the rotating gear ring 7 drives the lifting nozzle 5 to perform a circular motion through the fixed rod 6; Please refer to Figure 2 And Figure 3, a linkage pipe 10 is fixedly connected to the lower end of the rotating pipe 501. The linkage pipe 10 is rotatably connected to a rotating sleeve 11, and the rotating sleeve 11 is fixedly connected to the housing 1. A liquid outlet pipe 12 is fixedly connected to the lower end of the rotating sleeve 11, and the liquid outlet pipe 12 is fixedly connected to the output end of a water pump 14. The water pump 14 is fixedly connected to the inner wall of the housing 1; the input end of the water pump 14 is fixedly connected to a liquid suction pipe 15, and the liquid suction pipe 15 is fixedly connected to a liquid storage tank 16, and the liquid storage tank 16 is filled with cleaning water; Please refer to Figure 4 , the controller 4 is equipped with a maintenance system. The maintenance system includes a control module. The input ends of the control module are respectively connected to a rainfall monitoring module, a dust quantity monitoring module, a timing module and a self-check module. The input ends of the rainfall monitoring module and the dust quantity monitoring module are both connected to a piezoelectric characteristic recognition module. The input end of the piezoelectric characteristic recognition module is connected to the piezoelectric vibrator 3. The piezoelectric characteristic recognition module identifies the category of the electrical signal generated after the piezoelectric vibrator 3 is impacted. The rainfall monitoring module calculates the rainfall based on the raindrop impact signal collected by the piezoelectric vibrator 3, and the dust quantity monitoring module calculates the cumulative dust impact quantity based on the dust impact signal collected by the piezoelectric vibrator 3. The timing module is used for real-time timing. The self-check module is used to compare the real-time cumulative dust impact quantity with the set dust maintenance impact quantity on the one hand, and to confirm whether the real-time time reaches the set maintenance time on the other hand; the output end of the control module is connected to an execution module, and the output ends of the execution module are respectively connected to the rotating motor 9 and the water pump 14.

[0022] Specifically, please refer to Figure 9 , when in use, it includes the following steps: Step 1, based on the collection of the impact vibration signal by the piezoelectric vibrator 3 and the identification of the impact signal category by the piezoelectric characteristic recognition module, the rainfall monitoring module and the dust quantity monitoring module in the controller 4 monitor the rainfall and the cumulative dust impact quantity in real time; Step 2, the self-check module compares the cumulative dust impact quantity with the set dust maintenance impact quantity. When the cumulative dust impact quantity is not less than the set dust maintenance impact quantity, the execution module starts the rotating motor 9 and the water pump 14 to rotate and wash the impact surface of the impact cover 2 until the washing time reaches the set washing time, and then the execution module turns off the rotating motor 9 and the water pump 14; when the cumulative dust impact quantity is less than the set dust maintenance impact quantity, go to Step 3; Specifically, the rotating motor 9 drives the rotating gear ring 7 to rotate through the driving gear 8. The rotating gear ring 7 drives the lifting spray pipe 5 to make a circular motion through the fixing rod 6. At the same time, the water pump 14 injects the cleaning water in the liquid storage tank 16 into the fixing pipe 501 through the liquid suction pipe 15, the rotating sleeve 11 and the liquid outlet pipe 12. The cleaning water pushes the sliding pipe 502 to extend above the fixing pipe 501, so that the cleaning water sprays out from the spray holes 5021, and the sprayed cleaning water washes the impact surface of the impact cover 2; It should be noted that by controlling the output water pressure of the water pump 14 and then cooperating with the spring 503 to adjust the extension height of the sliding tube 502, each position of the impact surface of the impact cover 2 is flushed, improving the dust cleaning effect.

[0023] Step 3, when the real-time time reaches the set maintenance time, the execution module starts the rotation motor 9 and the water pump 14, and until the flushing time reaches the set flushing time, the execution module shuts down the rotation motor 9 and the water pump 14; when the real-time time does not reach the set maintenance time, no operation is performed.

[0024] Specifically, when the cumulative dust impact amount has not reached the set dust maintenance impact amount, but the real-time time reaches the set maintenance time, it is also necessary to flush the impact surface of the impact cover 2. The purpose of such a setting is that when the impact cover 2 receives the impact of a sandstorm, the dust on the surface of the impact cover 2 can be cleaned in time. When there is no sandstorm, the natural sedimentation dust on the surface of the impact cover 2 is flushed at the set time interval, improving the rain gauge measurement accuracy of the rain gauge and reducing the influence of natural accumulation dust and sandstorm accumulation dust on the rain measurement accuracy.

[0025] Compared with the traditional piezoelectric rain sensor, the present invention identifies the dust particle impact characteristics through the piezoelectric characteristic identification module and monitors the cumulative dust impact amount through the dust amount monitoring module. When one of the two situations that the real-time time reaches the set maintenance time or the cumulative dust impact amount reaches the set maintenance dust impact amount occurs, the rotation motor 9 and the water pump 14 are started to rotate and flush the impact surface of the impact cover 2, reducing the influence of dust on the measurement accuracy of the piezoelectric rain gauge, replacing on-site manual maintenance, and improving the maintenance efficiency and cost performance.

[0026] Please refer to Figure 8 , the housing 1 has a multi-stage frustum-shaped structure, the impact cover 2 has an arc-shaped cover structure and a collar is fixedly connected to the lower end. The collar is sleeved on the upper part of the housing 1 and fixedly connected to the housing 1 by means of bolts. The diameter of the lower end surface of the impact cover 2 is larger than the diameter of the upper end surface of the housing 1. The upper end surface of the rotating tube 501 is flush with the lower end surface of the impact cover 2. After the sliding tube 502 extends out of the rotating tube 501, the spray holes 5021 always face the impact surface of the impact cover 2.

[0027] Specifically, when the cleaning water flushes the surface of the impact cover 2, the sediment sewage flows along the impact surface of the impact cover 2 to the outside of the housing 1, reducing the pollution of the housing 1 by the sediment sewage. At the same time, the cleaning water sprayed from the spray holes 5021 always sprays towards the impact surface of the impact cover 2.

[0028] Please refer to Figure 8, the rotating toothed ring 7 is of an annular structure, and its inner circumferential wall is provided with tooth grooves evenly distributed in a circumferential manner. The housing 1 is provided with an annular groove for the rotating toothed ring 7 to rotate, and the housing 1 is provided with an open slot 101 communicating the annular groove with the inner cavity of the housing 1. The driving gear 8 penetrates through the open slot 101.

[0029] Specifically, the driving of the rotating toothed ring 7 is realized, and the rotating toothed ring 7 has better stability when rotating on the surface of the housing 1.

[0030] Please refer to Figure 8 , the rotating sleeve 11 includes an annular cover 1101 fixedly sleeved with the housing 1 and an annular plate 1102 rotatably connected to the annular cover 1101. An annular cavity is formed by enclosing between the annular plate 1102 and the annular cover 1101. The linkage pipe 10 is fixedly connected to the annular plate 1102 and communicates with the annular cavity.

[0031] Specifically, the cleaning water is injected into the lifting spray pipe 5 that makes a circular motion through the rotating sleeve 11.

[0032] Please refer to Figure 2 , the lower end of the rain gauge body is fixedly connected with a mounting rod 18, and the liquid storage tank 16 is fixedly connected with the mounting rod 18.

[0033] Specifically, the rain gauge body is installed through the mounting rod 18.

[0034] The second implementation mode: Figure 1 , Figure 4 and Figure 5 show a rain sensor based on a multi-layer piezoelectric thin film. On the basis of the first implementation mode, an electromagnetic flow valve 13 is fixedly connected to the liquid outlet pipe 12. The electromagnetic flow valve 13 is used to detect the amount of clean water flowing into the lifting spray pipe 5. The rain monitoring module includes a piezoelectric water volume unit and an analog water volume unit. The piezoelectric water volume unit is used to obtain rain data measured based on the piezoelectric oscillator 3, and the analog water volume unit is used to obtain water volume data measured by the electromagnetic flow valve 13; the self-checking module includes a dust self-checking unit and an accuracy self-checking unit. The dust self-checking unit is used to compare the cumulative dust impact amount with the set maintenance dust impact amount, and the accuracy self-checking unit is used to compare the rain data and the water volume data; the maintenance system further includes a warning module connected to the output end of the control module. The warning module is used to send a warning instruction to the remote monitoring room.

[0035] Specifically, the accuracy self-checking includes the following steps: Step 1, when the dust self-check is completed and the flushing operation is carried out or when the set accuracy self-checking time is reached, start the accuracy self-check. The accuracy self-checking unit sends an accuracy test instruction to the execution module. The execution module starts the rotating motor 9, the water pump 14 and the electromagnetic flow valve 13, and sprays a set amount of clean water onto the impact surface of the impact cover 2 for accuracy testing; Step 2: During the accuracy test, the piezoelectric water volume unit obtains the measured cumulative rainfall data based on the piezoelectric oscillator 3. The accuracy self-check unit compares the measured cumulative rainfall data with the set quantity of the sprayed clean water. When the difference between the measured cumulative rainfall data and the set quantity of the sprayed clean water is less than the set difference threshold, it is determined that the measurement accuracy of the rain gauge meets the requirements; when the absolute value of the difference between the measured cumulative rainfall data and the set quantity of the sprayed clean water is not less than the set minimum threshold, it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements. Step 3: When it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements, the warning module sends a warning instruction to the remote monitoring room to notify the operator that the current measurement accuracy of the rain gauge does not meet the requirements and wait for the operator to handle it subsequently.

[0036] It should be noted that when the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements, after receiving the warning instruction, the operator can arrange on-site maintenance personnel to go to the site for maintenance, or when it is found that the accuracy does not meet the measurement accuracy requirements after dust flushing and accuracy testing, perform dust flushing operations for the set number of times again and conduct accuracy testing. When the accuracy still does not meet the measurement accuracy requirements after multiple flushing and multiple accuracy testing for the set number of times, on-site maintenance personnel are dispatched.

[0037] Compared with the traditional piezoelectric rain gauge, in the present invention, the accuracy self-check unit of the self-check module performs accuracy self-check after the dust flushing operation. The electromagnetic flow valve 13 and the water pump 14 cooperate to spray a set quantity of clean water as simulated rain onto the impact cover 2. The piezoelectric oscillator 3 is used to obtain piezoelectric rainfall data, and the accuracy self-check unit compares the cumulative rainfall data measured by the piezoelectric oscillator 3 during the test with the set quantity of clean water for testing, thereby determining the accuracy of the rain gauge and further determining the cleaning effect after the dust flushing operation; at the same time, regular accuracy self-check is performed through the accuracy self-check unit to timely detect the deviation of the measurement accuracy of the rain gauge, which is convenient for subsequent processing; in addition, when the real-time measurement accuracy does not meet the measurement accuracy requirements, the warning module issues a warning instruction to remind the operator to dispatch on-site personnel or perform multiple dust flushing operations, improving the maintenance quality.

[0038] It should be noted that when the rain gauge undergoes equipment aging or failure, the measurement accuracy of the rain gauge will also decrease. Therefore, regular accuracy testing is required; in addition, when performing accuracy testing, it is necessary to conduct the test on a sunny and windless day to avoid the influence of rainfall and natural wind on the test results. Therefore, a wind speed sensor 17 is fixedly connected to one side of the housing 1.

[0039] Please refer to Figure 4 , the controller 4 further includes a communication module, and the communication module is connected to the output end of the warning module.

[0040] Please refer toFigure 1 and Figure 4 , the maintenance system further includes a foreign object impact monitoring module connected to the input end of the control module. The input end of the foreign object impact monitoring module is connected to the piezoelectric feature recognition module. The foreign object impact monitoring module is used to monitor the impact force and the number of impacts generated when a foreign object impacts the impact cover 2. When the foreign object impact force and the number of impacts reach the set values, an instruction to perform a dust flushing operation and a precision self-check operation is issued.

[0041] Specifically, the foreign object impact monitoring module timely discovers the situation where the impact cover 2 is impacted by a foreign object, and timely starts the dust flushing operation and the precision test operation. When the precision test does not meet the precision requirements, the warning module issues a warning instruction to the remote monitoring room, facilitating the timely dispatch of on-site maintenance personnel; It should be particularly noted that the vibration waveform characteristics of foreign object impacts are stored in the foreign object impact monitoring module. The vibration waveform characteristics of foreign object impacts are obtained through multiple tests and records by personnel, which will not be elaborated in this application.

[0042] Combined with the current actual requirements, the above implementation manner adopted in this application does not limit the protection scope thereto. Within the scope of knowledge possessed by those skilled in the art, various changes made without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A rain sensor based on a multi-layer piezoelectric thin film, characterized in that It includes a rain gauge body; the rain gauge body includes a housing (1), an impact cover (2) is fixedly connected to the upper end of the housing (1), a piezoelectric vibrator (3) is adhesively fixed to the inner wall of the impact cover (2), the piezoelectric vibrator is made of a multi-layer piezoelectric thin film, and the piezoelectric vibrator (3) is electrically connected to a controller (4) fixed in the housing (1); A lifting spray pipe (5) for flushing the impact cover (2) is arranged outside the housing (1). The lifting spray pipe (5) includes a rotating pipe (501), a sliding pipe (502) is slidably connected in the rotating pipe (501), and the sliding pipe (502) abuts against a spring (503) nested in the rotating pipe (501); a spray hole (5021) that abuts against the inner wall of the rotating pipe (501) is opened in the upper part of the sliding pipe (502); a fixed rod (6) is fixedly connected to the outer wall of the rotating pipe (501), the fixed rod (6) is fixedly connected to a rotating toothed ring (7) rotatably connected to the housing (1), a driving gear (8) is meshed inside the rotating toothed ring (7), the driving gear (8) is fixedly connected to the output shaft of a rotating motor (9), and the rotating motor (9) is fixedly connected in the housing (1); The lower end of the rotating pipe (501) is fixedly communicated with a linkage pipe (10), the linkage pipe (10) is rotatably communicated with a rotating sleeve (11), the rotating sleeve (11) is fixedly connected to the housing (1), the lower end of the rotating sleeve (11) is fixedly communicated with a liquid outlet pipe (12), the liquid outlet pipe (12) is fixedly communicated with the output end of a water pump (14), and the water pump (14) is fixedly connected to the inner wall of the housing (1); the input end of the water pump (14) is fixedly communicated with a liquid suction pipe (15), the liquid suction pipe (15) is fixedly communicated with a liquid storage tank (16), and the liquid storage tank (16) is filled with clean water; The controller (4) is equipped with a maintenance system. The maintenance system includes a control module. The input ends of the control module are respectively connected with a rain monitoring module, a dust amount monitoring module, a timing module and a self-check module. The input ends of the rain monitoring module and the dust amount monitoring module are both connected to a piezoelectric feature recognition module, and the input end of the piezoelectric feature recognition module is connected to the piezoelectric vibrator (3); the output end of the control module is connected with an execution module, and the output end of the execution module is respectively connected to the rotating motor (9) and the water pump (14).

2. The rain sensor based on a multilayer piezoelectric thin film according to claim 1, wherein, An electromagnetic flow valve (13) is fixedly connected to the liquid outlet pipe (12). The electromagnetic flow valve (13) is used to detect the amount of clean water flowing into the lifting spray pipe (5). The rain monitoring module includes a piezoelectric water volume unit and an analog water volume unit. The piezoelectric water volume unit is used to obtain rain data measured based on the piezoelectric vibrator (3), and the analog water volume unit is used to obtain water volume data measured by the electromagnetic flow valve (13); the self-check module includes a dust self-check unit and a precision self-check unit. The dust self-check unit is used to compare the cumulative dust impact amount with the set maintenance dust impact amount, and the precision self-check unit is used to compare the rain data and the water volume data; the maintenance system also includes a warning module connected to the output end of the control module, and the warning module is used to send a warning instruction to the remote monitoring room.

3. The rain sensor based on a multi-layer piezoelectric thin film according to claim 1, characterized in that The housing (1) has a multi-stage frustum-like structure. The impact cover (2) has an arc-shaped cover structure and a collar is fixedly connected to its lower end. The collar is sleeved on the upper part of the housing (1) and is fixedly connected to the housing (1) by means of bolts. The diameter of the lower end face of the impact cover (2) is larger than the diameter of the upper end face of the housing (1). The upper end face of the rotating pipe (501) is flush with the lower end face of the impact cover (2). After the sliding pipe (502) extends out of the rotating pipe (501), the spray holes (5021) always face the impact surface of the impact cover (2).

4. The rain sensor based on a multi-layer piezoelectric film according to claim 1, characterized in that, The rotating gear ring (7) is a ring structure and its inner circumferential wall is provided with tooth grooves that are circumferentially equidistantly distributed. The housing (1) is provided with an annular groove for the rotation of the rotating gear ring (7). The housing (1) is provided with an open groove (101) that communicates the annular groove and the inner cavity of the housing (1). The driving gear (8) penetrates through the open groove (101).

5. The rain sensor based on a multi-layer piezoelectric thin film according to claim 1, characterized in that, The rotating sleeve (11) includes an annular cover (1101) fixedly sleeved on the housing (1) and an annular plate (1102) rotatably connected to the annular cover (1101). An annular cavity is formed by enclosing between the annular plate (1102) and the annular cover (1101). The linkage pipe (10) is fixedly connected to the annular plate (1102) and communicates with the annular cavity.

6. The rain sensor based on a multi-layer piezoelectric thin film according to claim 2, characterized in that, The controller (4) further includes a communication module, and the communication module is connected to the output end of the warning module.

7. The rain sensor based on a multi-layer piezoelectric thin film according to claim 2, characterized in that, The maintenance system further includes a foreign object impact monitoring module connected to the input end of the control module. The input end of the foreign object impact monitoring module is connected to the piezoelectric characteristic identification module. The foreign object impact monitoring module is used to monitor the impact force and the number of impacts generated when a foreign object impacts the impact cover (2).

8. The rain sensor based on a multi-layer piezoelectric thin film according to claim 1, characterized in that, When in use, it includes the following steps: Step 1, based on the collection of impact vibration signals by the piezoelectric vibrator (3) and the identification of the impact signal categories by the piezoelectric characteristic identification module, the rainfall monitoring module and the dust accumulation impact amount monitoring module in the controller (4) monitor the rainfall amount and the dust accumulation impact amount in real time; Step 2, the self-check module compares the dust accumulation impact amount with the set dust maintenance impact amount. When the dust accumulation impact amount is not less than the set dust maintenance impact amount, the execution module starts the rotating motor (9) and the water pump (14) to rotate and wash the impact surface of the impact cover (2) until the washing time reaches the set washing time, and then the execution module shuts down the rotating motor (9) and the water pump (14); when the dust accumulation impact amount is less than the set dust maintenance impact amount, go to Step 3; Step 3, when the real-time time reaches the set maintenance time, the execution module starts the rotating motor (9) and the water pump (14) until the washing time reaches the set washing time, and then the execution module shuts down the rotating motor (9) and the water pump (14); when the real-time time does not reach the set maintenance time, no operation is performed.

9. The rainfall sensor based on a multi-layer piezoelectric thin film according to claim 2, characterized in that, When performing precision self-check, it includes the following steps: Step 1: When the dust self-check is completed and the flushing operation is carried out, or when the set precision self-check time is reached, start the precision self-check. The precision self-check unit sends a precision test instruction to the execution module, and the execution module starts the rotation motor (9), the water pump (14) and the electromagnetic flow valve (13) to spray a set amount of clean water onto the impact surface of the impact cover (2) for precision testing; Step 2: During the precision test, obtain the measured cumulative rainfall data based on the piezoelectric vibrator (3) through the piezoelectric water volume unit. The precision self-check unit compares the measured cumulative rainfall data with the set amount of the sprayed clean water. When the difference between the measured cumulative rainfall data and the set amount of the sprayed clean water is less than the set difference threshold, it is determined that the measurement accuracy of the rain gauge meets the requirements; When the absolute value of the difference between the measured cumulative rainfall data and the set amount of the sprayed clean water is not less than the set minimum threshold, it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements; Step 3: When it is determined that the measurement accuracy of the rain gauge does not meet the measurement accuracy requirements, the warning module sends a warning instruction to the remote monitoring room to notify the operator that the current measurement accuracy of the rain gauge does not meet the requirements and wait for the operator to process it later.

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