Weak wind pressure measuring device based on piezoelectric effect

Abstract

A weak wind pressure measuring device based on a piezoelectric effect comprises a base platform, a hollow main machine shell, an air duct structure arranged in the hollow main machine shell and extending in the longitudinal direction; the wind power generation device is fixed at one end in the shell and is used for generating directional airflow; the sensor device is arranged on the airflow path and comprises a piezoelectric sensing element for converting wind pressure into an electric signal; the linear displacement mechanism is arranged in the shell and used for driving the sensor device to move along the axis of the air duct so as to adjust the linear distance between the sensor device and the wind power generation device; the signal conditioning device is connected with the output end of the piezoelectric sensing element and is used for processing the original electric signal; and the controller is used for controlling the overall operation and data processing of the device. According to the invention, the high-sensitivity piezoelectric sensing element is combined with an adjustable internal measurement structure, so that high-precision and quick response measurement of weak wind pressure is realized, and the problems of difficulty in breeze measurement and low precision in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a weak wind pressure measuring device based on piezoelectric effect. BACKGROUND

[0002] Wind speed and wind pressure are key measurement parameters in many fields such as meteorology, fluid mechanics, environmental science, and industrial production. Accurate measurement of wind field, especially weak wind field, is of great significance for weather forecasting, pollution dispersion model construction, wind farm site selection, building wind resistance design, and clean room environment monitoring.

[0003] Currently, the measurement techniques of wind speed or wind pressure mainly include the following categories:

[0004] 1. Mechanical measurement technique: This is the most traditional and widely used method, and its representative instrument is the wind cup or propeller anemometer. This kind of instrument indirectly calculates the wind speed by measuring the rotation speed of the mechanical components (such as wind cups or propellers) driven by the wind. However, the mechanical measurement method has inherent defects: first, its sensitivity is low, due to the frictional resistance and rotational inertia of the mechanical structure, there is a "starting wind speed", when the wind speed is lower than this threshold, the instrument cannot respond, so it is completely not suitable for accurate measurement of weak wind field, resulting in large measurement error. Secondly, its dynamic response performance is poor, the inertia of the mechanical components makes it unable to follow the rapid pulsation of wind speed, the response time is usually seconds, which cannot capture the fine structure of wind field turbulence.

[0005] 2. Pressure measurement technique: represented by Pitot tube, which measures the difference between total pressure and static pressure to calculate wind speed. This technique is accurate at higher wind speeds, but when the wind speed is very low, the dynamic pressure is extremely weak, requiring high resolution and accuracy of pressure sensors, resulting in low signal-to-noise ratio in a breeze environment, making measurement difficult and error large.

[0006] 3. Thermal measurement technique: such as hot-wire or hot-film anemometer, which determines wind speed by measuring the heat dissipation rate of the heated element cooled by wind flow. This technique has high sensitivity and response speed, but its sensor probe is easily contaminated by dust in the air, leading to performance degradation, poor durability, and sensitivity to changes in environmental temperature and humidity, requiring frequent calibration and high maintenance cost.

[0007] 4. Acoustic measurement technique: ultrasonic anemometer measures the time difference between the forward and reverse propagation of ultrasonic waves in air to calculate wind speed. This technique has no moving parts, high measurement accuracy and response speed. However, the structure of ultrasonic anemometer is complex, the cost is high, and its acoustic transducer is easily affected by rain, snow, icing and other harsh weather conditions, limiting its application in some environments.

[0008] In summary, the prior art has obvious deficiencies in the measurement of weak wind pressure. The traditional mechanical instrument cannot be competent due to the limitation of sensitivity and response speed; while other advanced technologies have improved performance, but they are generally high in cost, susceptible to environmental interference, complex in maintenance or limited in application scenarios. In addition, most of the existing measurement equipment is fixedly installed, and it is difficult to obtain the spatial distribution characteristics of the wind field, and there is a lack of a low-cost and high-performance solution that can be integrated into a mobile platform (such as a UAV) for large-scale and high-precision dynamic detection in complex environments. The technical background part of the present application aims to explain the current situation in the prior art, and the deficiencies of the prior art show that this part will provide the necessary background information for understanding the technical contributions and innovations of the present application. The signals disclosed in this background technology part only aim to increase the understanding of the overall background of the present application, and should not be considered as implying subjective awareness in any form. SUMMARY

[0009] In view of the above, the purpose of the present application is to provide a weak wind pressure measuring device based on piezoelectric effect.

[0010] The technical scheme adopted to achieve the purpose of the present application is a weak wind pressure measuring device based on piezoelectric effect, comprising:

[0011] A base platform for carrying all components rigidly, the base platform is a planar structure;

[0012] A main body shell fixed to the base platform, and an air duct structure is provided inside, the air duct structure is a semicylindrical hollow channel extending along the longitudinal axis of the main body shell, the air duct structure is used to constrain the directional airflow, so that it stably acts on the sensor device to realize effective measurement of weak wind pressure;

[0013] A wind power generation device fixedly installed at one end of the main body shell and opposite to the air inlet of the air duct structure, located at one end of the air duct structure, used to generate a directional airflow propagating along the longitudinal axis of the air duct structure and capable of exerting weak wind pressure, the airflow can stably enter and be constrained inside the air duct structure;

[0014] A sensor device is movably arranged inside the main body shell and always located on the directional airflow path generated by the wind power generation device, the sensor device comprising a piezoelectric sensing element for sensing the weak wind pressure; the sensing surface of the piezoelectric sensing element is perpendicular and positively oriented to the wind power generation device, so that the directional airflow positively impacts on the sensing surface of the piezoelectric sensing element; when the weak wind pressure acts on the sensing surface, the element mechanically deforms, and based on its inherent positive piezoelectric effect, generates a weak electric charge signal between the electrode surfaces of the element in proportion to the degree of mechanical deformation.

[0015] A linear displacement mechanism is mounted on the base platform, the movement output end of which is mechanically connected with the sensor device, and the sensor device is fixedly mounted on the movement output end of the linear displacement mechanism and moves therewith, for driving the sensor device to reciprocatingly move linearly along the longitudinal axis of the air duct structure, so as to adjust the distance between the sensor device and the wind power generation device; the linear displacement mechanism measures the wind pressure at different distances by changing the relative position between the sensor device and the wind power generation device.

[0016] Further, the wind power generation device comprises a driving motor and a fan; the body of the driving motor is fixedly mounted on the main body shell, and the output shaft thereof is coaxially arranged towards the air inlet of the air duct structure; the fan is fixedly connected to the output shaft end of the driving motor, and the rotating plane of the fan blades is perpendicular to the longitudinal axis of the air duct structure.

[0017] Further, the linear displacement mechanism comprises:

[0018] A guide rail parallel to the longitudinal axis of the air duct structure, which is fixed to the base platform;

[0019] A sliding table in sliding cooperation with the guide rail, and the sensor device is fixedly mounted on the sliding table;

[0020] A transmission assembly, which comprises a rack fixed to the base platform and parallel to the guide rail, and a gear engaged with the rack;

[0021] A positioning motor, the output shaft of which is coaxially fixedly connected with the gear, and the body of the positioning motor is fixedly connected with the sliding table; the positioning motor is used to drive the gear to roll along the fixed rack, thereby driving the sliding table and the sensor device mounted thereon to linearly move along the guide rail.

[0022] Further, the sensor device further comprises a sensor mounting frame fixed on the moving output end of the linear displacement mechanism; the piezoelectric sensing element is a flexible piezoelectric film, the edges of which are tensioned and fixed on the sensor mounting frame so that the sensing surface remains flat and perpendicular to the longitudinal axis of the air duct structure.

[0023] Further, the piezoelectric sensing element comprises:

[0024] the flexible piezoelectric film body;

[0025] and a first electrode layer and a second electrode layer respectively coated on the two opposite main surfaces of the flexible piezoelectric film body; the first electrode layer and the second electrode layer constitute the electrode output end of the piezoelectric sensing element electrically connected to the signal conditioning device through the lead wires.

[0026] Further, the signal conditioning device is a circuit module, the signal input end of which is electrically connected to the electrode output end of the piezoelectric sensing element, for charge-voltage conversion, amplification and filtering processing of the weak electric charge signal generated by the piezoelectric sensing element due to the weak wind pressure, to form a stable voltage signal easy to collect.

[0027] Further, the signal conditioning device comprises a signal amplification unit and a signal filtering unit; the electrode output end of the piezoelectric sensing element is connected to the input end of the signal amplification unit, the output end of the signal amplification unit is connected to the input end of the signal filtering unit, and the output end of the signal filtering unit serves as the final signal output end of the signal conditioning device.

[0028] Further, the controller is a micro-processing unit, the control output end of which is electrically connected to the wind power generation device and the linear displacement mechanism respectively, and the signal acquisition input end of which is electrically connected to the signal output end of the signal conditioning device, for controlling the start-stop of the wind power generation device and the airflow intensity, driving the precise positioning of the linear displacement mechanism, collecting and processing the signal processed by the signal conditioning device, and finally calculating the value of the weak wind pressure according to the signal and the position information of the sensor device.

[0029] Further, the controller further integrates or externally connects a display unit and an external communication interface; the display unit is electrically connected to the controller, for visual display of the wind pressure data calculated by the controller according to the collected signal; the external communication interface is electrically connected to the controller, for transmitting the measurement data to an external computing or storage device.

[0030] Further, the method comprises the following steps:

[0031] a: position calibration step: the controller sends a first control instruction to the positioning motor in the linear displacement mechanism to drive the sensor device to move along the guide rail to a preset initial measurement position;

[0032] b: wind field generation step: the controller sends a second control instruction to the drive motor in the wind generating device to drive the fan to rotate at a stable speed, generating a stable and continuous directional airflow that propagates along the air duct structure and continuously acts on the surface of the piezoelectric sensing element of the sensor device;

[0033] c: signal conversion step: the flexible piezoelectric film of the piezoelectric sensing element undergoes mechanical deformation due to the wind pressure generated by the directional airflow, and based on its positive piezoelectric effect, generates an original charge signal between the first and second electrode layers proportional to the deformation amount;

[0034] d: signal conditioning step: the original charge signal is sequentially processed by the signal amplification unit and signal filtering unit in the signal conditioning device, and converted into a stable analog voltage signal with enhanced amplitude and noise removed;

[0035] e: data acquisition and processing step: the controller performs analog-to-digital conversion on the analog voltage signal through its signal acquisition input, obtains digitized voltage sample values, and converts the digitized voltage sample values to final wind pressure values according to the calibration model algorithm preset in the controller;

[0036] f: result output step: the controller sends the calculated wind pressure values to the display unit for real-time display through the internal data bus, or to external devices through the external communication interface.

[0037] Advantages of the present application:

[0038] 1. High measurement sensitivity and fast dynamic response: The present application uses flexible piezoelectric film as the core sensing element, which can directly convert extremely weak wind pressure into electrical signals using its positive piezoelectric effect. This fundamentally overcomes the starting wind speed threshold problem of traditional mechanical anemometers due to friction and inertia, achieving high sensitivity detection of airflow disturbances in a breeze or even static wind environment. At the same time, the inherent high frequency response characteristics of piezoelectric materials make the response time of the present application reach milliseconds, which can accurately capture the transient changes and turbulence details of the wind field, far superior to the response delay of traditional mechanical instruments in seconds.

[0039] 2. High integration, self-calibration and range expansion can be realized: The wind power generation device and the linear displacement mechanism are innovatively integrated in the closed housing. This design not only provides a controllable internal test environment for the device, enabling automatic in-situ calibration and self-calibration, ensuring the accuracy of long-term measurement; but also can actively change the pressure acting on the sensor element by precisely adjusting the distance between the sensor and the wind source, effectively expanding the effective measurement range of the device, so that it can adapt to different intensity of weak wind field environment.

[0040] 3. System automation, strong data processing capability: The invention realizes the high automation of the measurement process through the central controller to uniformly coordinate the wind power generation, sensor positioning, signal acquisition and data processing, etc. The controller built-in algorithm model can amplify, filter and solve the collected original signal in real time, directly output accurate wind pressure value, and can be displayed and transmitted through the display unit or communication interface, with complete functions and convenient use.

[0041] 4. Wide application scenarios, with mobile detection capability: By integrating the measurement device with the unmanned aerial vehicle platform, the invention breaks through the limitations of traditional ground fixed station measurement. The monitoring system can flexibly and quickly reach the specified airspace, and can conduct large-scale, high-resolution three-dimensional dynamic mapping of wind field in complex terrain, dangerous areas or high-altitude environment, providing a new and powerful technical means for meteorological research, environmental monitoring, precision agriculture and other fields. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0043] Figure 1 is a structural schematic diagram of the present application;

[0044] Figure 2 is a structural sectional view of the present application;

[0045] Figure 3 is a longitudinal view of the present application;

[0046] Figure 4 is a linear displacement mechanism schematic diagram of the present application;

[0047] In the figure, 100 - main body shell, 101 - wind generating device, 102 - sensor device, 103 - linear displacement mechanism, 200 - guide rail, 201 - sliding table, 202 - positioning motor, 203 - gear, 300 - base platform. DETAILED DESCRIPTION

[0048] The application will be described in the following with reference to the drawings and some embodiments.

[0049] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0050] The piezoelectric effect-based weak wind pressure measuring device of the present application will be further described below in combination with the drawings and embodiments, which aims to help understand the technical concept and specific implementation mode of the present application, but the description should not be understood as a limitation on the protection scope of the present application.

[0051] Referring to Figures 1-3 As shown in the figure, the present application provides a piezoelectric effect-based weak wind pressure measuring device, which can realize high-precision and high-sensitivity measurement of weak air flow pressure.

[0052] Embodiment 1,

[0053] In a preferred embodiment, the base platform serves as the bearing basis of the entire device, providing a stable and rigid mounting plane for all other components, ensuring the stability and accuracy of the measurement.

[0054] The main body shell is fixed on the base platform. Its internal core structure is a wind channel structure, which is designed as a semi-cylindrical hollow passage extending along the longitudinal axis of the main body shell in this embodiment. This semi-open channel design can effectively constrain and guide the air flow, forming a relatively stable and uniform wind field environment, reducing the interference of the external environment; on the other hand, it is also convenient for observation and debugging of the internal sensor device.

[0055] The wind generating device is fixedly installed at one end of the main body shell, and its air outlet is opposite to the air inlet of the wind channel structure. The device is used to generate a directional air flow propagating along the longitudinal axis of the wind channel structure. Specifically, the wind generating device can include a driving motor and a fan. The body of the driving motor is fixed on the main body shell, and its output shaft is coaxially arranged with the longitudinal axis of the wind channel structure. The fan is fixedly connected to the end of the output shaft of the driving motor, and the rotating plane of the fan blade is perpendicular to the longitudinal axis of the wind channel structure. By precisely controlling the rotating speed of the driving motor through the controller, a stable wind source with adjustable intensity can be generated.

[0056] The sensor device is the core measurement unit of this invention. It is movably mounted inside the main housing and is always positioned along the path of the directional airflow generated by the wind generator. At the heart of this sensor device is a piezoelectric sensing element, whose function is to efficiently convert the mechanical deformation caused by the measured wind pressure into a measurable electrical charge signal based on the positive piezoelectric effect. In this embodiment, the sensing surface of the piezoelectric sensing element faces the wind generator, ensuring that the directional airflow acts positively on its surface, thereby maximizing measurement sensitivity.

[0057] To further optimize the structure of the sensor device, the device also includes a sensor mounting frame. The piezoelectric sensing element is preferably a flexible piezoelectric thin film (e.g., a PVDF film), the edges of which are uniformly stretched and fixed to the sensor mounting frame. This mounting method ensures that the sensing surface of the piezoelectric film remains flat when not under stress, and that its plane is perpendicular to the longitudinal axis of the duct structure, which is crucial for ensuring the stability of the measurement reference and the accuracy of the results.

[0058] The piezoelectric sensing element comprises a flexible piezoelectric thin film body and a first electrode layer and a second electrode layer respectively deposited on two opposing main surfaces of the thin film body. These two electrode layers are connected to an external circuit via leads, forming the electrode output terminals of the piezoelectric sensing element. When wind pressure acts on the thin film, causing it to bend and deform, charge is generated and accumulated between the two electrode layers.

[0059] To achieve precise positioning of the sensor device within the air duct, this invention incorporates a linear displacement mechanism. This mechanism is mounted on a base platform, and its motion output end is mechanically connected to the sensor device. Its function is to drive the sensor device to reciprocate linearly along the longitudinal axis of the air duct structure, thereby precisely adjusting the distance between the sensor and the wind-generating device.

[0060] Specifically, the linear displacement mechanism can consist of the following components: one or more guide rails arranged parallel to the longitudinal axis of the air duct structure, fixed to a base platform; a slide table that slides with the guide rails, on which the aforementioned sensor device is fixedly mounted; a transmission assembly, which may include, for example, a rack fixed to the base platform and parallel to the guide rails, and a gear meshing with the rack; and a positioning motor (such as a stepper motor or servo motor), whose output shaft is coaxially and fixedly connected to the gear, while the motor body is fixed to the slide table. The controller sends commands to the positioning motor, driving the gear to roll along the fixed rack, thereby driving the entire slide table and the sensor device mounted thereon to perform high-precision linear movement and positioning along the guide rails.

[0061] The raw charge signal generated by a piezoelectric sensing element is typically very weak and easily affected by noise. To address this, the present invention includes a signal conditioning device. This is a circuit module whose signal input is electrically connected to the electrode output of the piezoelectric sensing element. Internally, the device may include a signal amplification unit and a signal filtering unit. The raw signal output from the piezoelectric sensing element first enters the signal amplification unit (such as a charge amplifier) ​​for amplification, increasing the signal amplitude. The amplified signal is then sent to the signal filtering unit (such as a low-pass filter) for processing, filtering out high-frequency noise and power frequency interference. After these two stages of processing, a stable and clean analog voltage signal is output.

[0062] The controller is the core of the entire device for control and data processing, typically a microprocessor unit (MCU) or an embedded system. Its control outputs are electrically connected to the drive motor of the wind turbine generator and the positioning motor of the linear displacement mechanism, respectively, to control the start / stop of the wind turbine generator, the airflow intensity, and the precise positioning of the linear displacement mechanism. Its signal acquisition input (usually an ADC port) is electrically connected to the signal output of the signal conditioning device, used to acquire and process the conditioned signal.

[0063] To facilitate user interaction and data management, the controller can also integrate or connect to an external display unit (such as an LCD or OLED screen) and an external communication interface (such as a USB or RS232 interface). The display unit is used to display wind pressure data or other status information calculated by the controller based on the acquired signals in real time and visually. The external communication interface is used to transmit measurement data in batches to an external computer or storage device for further analysis and recording.

[0064] Based on the above-described device, the present invention also provides a method for measuring weak wind pressure based on the piezoelectric effect, the method comprising the following steps:

[0065] Step a: Position calibration step. Before the measurement begins, the controller sends a first control command to the positioning motor in the linear displacement mechanism, driving the sensor device to move along the guide rail to a preset initial measurement position. This position can be the closest or farthest point from the wind generator, or any other designated calibration point.

[0066] Step b: Wind field generation step. The controller sends a second control command to the drive motor in the wind power generation device, causing it to drive the fan to rotate at a preset stable speed. The fan then generates a stable and continuous directional airflow, which propagates along the longitudinal axis under the constraint of the duct structure and continuously acts on the surface of the piezoelectric sensing element of the sensor device.

[0067] Step c: Signal conversion step. The flexible piezoelectric film of the piezoelectric sensing element undergoes slight mechanical deformation due to the wind pressure generated by the directional airflow. Based on its positive piezoelectric effect, the electric dipoles inside the film are polarized, resulting in the generation and accumulation of a primitive charge signal proportional to the deformation (i.e., wind pressure) between the first and second electrode layers.

[0068] Step d: Signal conditioning step. The original charge signal is transmitted to the signal conditioning device via leads. The signal is first amplified by the signal amplification unit, then filtered to remove noise by the signal filtering unit, and finally converted into a stable analog voltage signal with enhanced amplitude and high signal-to-noise ratio.

[0069] Step e: Data Acquisition and Processing. The controller periodically samples the analog voltage signal from the signal conditioning unit using its internal analog-to-digital converter (ADC), obtaining a series of digitized voltage sample values. Subsequently, the controller calculates and converts these digitized voltage sample values ​​into the final wind pressure physical quantity (e.g., in Pascals, Pa) based on a pre-stored calibration model algorithm. This calibration model can be obtained through prior experiments using known wind speeds or standard pressure gauges.

[0070] Step f: Result Output Step. The controller sends the calculated final wind pressure value to the display unit via the internal data bus for real-time display and direct reading by the operator. Simultaneously, or upon instruction, the controller can also package and send measurement data (which may include timestamps, location information, etc.) to external devices via an external communication interface, enabling remote monitoring and storage of the data.

[0071] By repeating the above steps, such as changing the rotation speed of the wind generator or changing the position of the sensor device, it is possible to systematically measure and study the weak wind pressure under different conditions.

[0072] Example 2: The present invention also provides weak wind pressure monitoring for mobile platforms, aiming to break through the geographical spatial limitations of traditional fixed measurement and realize high-precision dynamic monitoring of large-scale, high-altitude wind fields in complex environments.

[0073] In this embodiment, a weak wind pressure measurement device is integrated as the core sensing payload with a drone platform. This includes: a drone platform and a weak wind pressure measurement device fixed to the platform.

[0074] The drone platform is a multi-rotor or fixed-wing drone. In this embodiment, the integration of the weak wind pressure measurement device with the drone platform is achieved in the following way:

[0075] In this embodiment, the mechanical integration of the measuring device with the UAV platform is achieved through a connecting structure. This connecting structure is a mounting bracket, which includes a base, a connecting arm, and a clamping structure, and is made of lightweight, high-strength carbon fiber material.

[0076] Specifically, the shape and holes of the base match the reserved mounting points below the front end of the UAV's frame, and are fixedly connected by high-strength bolts to ensure stable installation. The clamping structure is a ring-shaped clamp or a split-type fixture adapted to the shape of the main housing of the measuring device (e.g., cylindrical), with cushioning material attached to its inner wall. The connecting arm connects the base and the clamping structure as a single unit.

[0077] To isolate the interference of high-frequency vibrations generated by the UAV's power system on the weak pressure measurements, a vibration damping unit is installed between the base and the connecting arm. This vibration damping unit can consist of multiple arrayed rubber damping balls or silicone damping columns, dividing the mounting bracket into upper and lower isolation sections, effectively absorbing and attenuating vibrations from the UAV body.

[0078] During installation, the base of the connecting structure is first fixed to the designated position at the front of the UAV's frame. Then, the main housing of the weak wind pressure measuring device is placed within the clamping structure and securely clamped using a locking mechanism (such as a hand-tightened screw). The final installation position ensures that the longitudinal axis of the measuring device is parallel to the UAV's flight direction, and that the air inlet at its front extends beyond the UAV's body, facing the forward airflow, thereby minimizing aerodynamic interference from the UAV's own rotor downwash flow field on the measurement.

[0079] On the data link, the controller of the measurement device and the flight control unit of the UAV platform establish a data communication connection through a serial communication interface (such as UART), and the two can exchange data according to a predefined communication protocol.

[0080] The integrated system operates as follows: During UAV flight missions, its onboard weak wind pressure measurement device (its internal wind generator is typically off) senses the wind pressure generated by the external airflow in real time. The measurement device's controller independently acquires, conditions, and calculates the signal to obtain precise wind pressure values. The controller then packages the wind pressure data and sends it to the UAV's flight control unit via a data communication connection. Upon receiving the wind pressure data, the flight control unit adds a timestamp and merges it with its own telemetry data (such as GPS coordinates, altitude, flight speed, and attitude angles) to form a comprehensive data frame. Finally, the flight control unit transmits this comprehensive data frame to the ground control station in real time via its own remote wireless communication module, thereby achieving dynamic, high-resolution 3D mapping of the wind field distribution in the target airspace.

[0081] In this way, ground station operators can not only monitor the flight status of the UAV, but also obtain weak wind pressure data at any point along the UAV's flight path in real time, thereby achieving dynamic, high-resolution three-dimensional mapping of the wind field distribution in the target airspace, providing key underlying data support for fields such as weather forecasting, environmental monitoring, agricultural plant protection, and wind farm site selection.

[0082] It should be noted that the above embodiments are merely preferred examples of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0083] The above-described specific embodiments are typical examples of the present invention, but the present invention is not limited thereto. Without departing from the core technical concept of the present invention, reasonable changes can be made to its structure, materials, and control logic, and all improvements based thereon fall within the protection scope of the present invention.

[0084] The specific embodiments of the present invention are merely illustrative and do not limit the scope of protection of the present invention. Various changes and modifications can be made to the specific embodiments of the present invention without departing from the spirit and essence of the invention. All such changes and modifications fall within the scope of the present invention.

[0085] It is worth noting that in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. In this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection. The circuits described in this invention are all circuits commonly used in the art, and other related components are all commonly used existing components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0086] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent elements of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A weak wind pressure measuring device based on the piezoelectric effect, characterized in that, include: A rigid base platform that supports all components, wherein the base platform is a planar structure; The main body housing is fixed to the base platform and has an internal air duct structure. The air duct structure is a semi-cylindrical hollow channel extending along the longitudinal axis of the main body housing. The air duct structure is used to constrain the directional airflow so that it acts stably on the sensor device to achieve effective measurement of weak wind pressure. A wind power generating device is fixedly installed at one end of the main body housing and faces the air inlet of the air duct structure. It is located at one end of the air duct structure and is used to generate a directional airflow that can be applied with a weak wind pressure and propagates along the longitudinal axis of the air duct structure. The airflow can stably enter and be constrained inside the air duct structure. A sensor device is movably disposed inside the main housing and is always located on the directional airflow path generated by the wind generating device. The sensor device includes a piezoelectric sensing element for sensing the weak wind pressure. The sensing surface of the piezoelectric sensing element is perpendicular to and faces the wind generating device, so that the directional airflow impacts the sensing surface of the piezoelectric sensing element in a positive direction. When the weak wind pressure acts on its sensing surface, the element undergoes mechanical deformation and, based on its inherent positive piezoelectric effect, generates a weak charge signal between the electrode surfaces of the element that is proportional to the degree of mechanical deformation. A linear displacement mechanism is installed on the base platform. Its motion output end is mechanically connected to a sensor device, which is fixedly installed on the motion output end of the linear displacement mechanism and moves with it. The sensor device is used to drive the sensor device to reciprocate linearly along the longitudinal axis of the wind duct structure, thereby adjusting the distance between it and the wind generating device. The linear displacement mechanism measures the wind pressure at different distances by changing the relative position between the sensor device and the wind generating device.

2. The weak wind pressure measuring device based on the piezoelectric effect according to claim 1, characterized in that, The wind power generating device includes a drive motor and a fan; the body of the drive motor is fixedly mounted on the main housing, and its output shaft faces the air inlet of the air duct structure and is coaxial with it; the fan is fixedly connected to the end of the output shaft of the drive motor, and the rotation plane of the fan blades is perpendicular to the longitudinal axis of the air duct structure.

3. The weak wind pressure measuring device based on the piezoelectric effect according to claim 1, characterized in that, The linear displacement mechanism includes: A guide rail is arranged parallel to the longitudinal axis of the air duct structure and is fixed to the base platform; A slide table that slides in cooperation with the guide rail, and the sensor device is fixedly mounted on the slide table; A transmission assembly, comprising a rack fixed to the base platform and parallel to the guide rail, and a gear meshing with the rack; A positioning motor is provided, wherein the output shaft of the positioning motor is coaxially and fixedly connected to the gear, and the body of the positioning motor is fixedly connected to the slide. The positioning motor is used to drive the gear to roll along the fixed rack, thereby driving the slide and the sensor device mounted thereon to move linearly along the guide rail.

4. The weak wind pressure measuring device based on the piezoelectric effect according to claim 1, characterized in that, The sensor device further includes a sensor mounting frame, which is fixed to the motion output end of the linear displacement mechanism; the piezoelectric sensing element is a flexible piezoelectric film, the edge of which is stretched and fixed to the sensor mounting frame so that its sensing surface remains flat and perpendicular to the longitudinal axis of the air duct structure.

5. The weak wind pressure measuring device based on the piezoelectric effect according to claim 4, characterized in that, The structure of the piezoelectric sensing element includes: The flexible piezoelectric thin film body; The first electrode layer and the second electrode layer are respectively laid on two opposite main surfaces of the flexible piezoelectric thin film body; the first electrode layer and the second electrode layer form the electrode output terminal electrically connected to the piezoelectric sensing element and the signal conditioning device through leads.

6. The weak wind pressure measuring device based on the piezoelectric effect according to claim 1, characterized in that, Also includes: The signal conditioning device is a circuit module whose signal input terminal is electrically connected to the electrode output terminal of the piezoelectric sensing element. It is used to perform charge-to-voltage conversion, amplification, and filtering on the weak charge signal generated by the piezoelectric sensing element due to weak wind pressure, so as to form a stable voltage signal that is easy to acquire.

7. The weak wind pressure measuring device based on the piezoelectric effect according to claim 6, characterized in that, The signal conditioning device includes a signal amplification unit and a signal filtering unit; the electrode output terminal of the piezoelectric sensing element is connected to the input terminal of the signal amplification unit, the output terminal of the signal amplification unit is connected to the input terminal of the signal filtering unit, and the output terminal of the signal filtering unit serves as the final signal output terminal of the signal conditioning device.

8. The weak wind pressure measuring device based on the piezoelectric effect according to claim 6, characterized in that, The controller is a microprocessor unit whose control output is electrically connected to the wind generating device and the linear displacement mechanism, and whose signal acquisition input is electrically connected to the signal output of the signal conditioning device. It is used to control the start and stop of the wind generating device and the airflow intensity, drive the precise positioning of the linear displacement mechanism, acquire and process the signal after it has been processed by the signal conditioning device, and finally calculate the value of the weak wind pressure based on the signal and the position information of the sensor device.

9. The weak wind pressure measuring device based on the piezoelectric effect according to claim 8, characterized in that, The controller also integrates or connects to a display unit and an external communication interface; the display unit is electrically connected to the controller and is used to visually display the wind pressure data calculated by the controller based on the collected signals; the external communication interface is electrically connected to the controller and is used to transmit the measurement data to an external computing or storage device.

10. The method for measuring weak wind pressure based on the piezoelectric effect according to any one of claims 1-9, characterized in that, The method includes the following steps: a: Position calibration step: The controller sends a first control command to the positioning motor in the linear displacement mechanism, driving the sensor device to move along the guide rail to the preset initial measurement position; b: Wind field generation step: The controller sends a second control command to the drive motor in the wind power generation device, so that it drives the fan to rotate at a stable speed, generating a stable and continuous directional airflow. The airflow propagates along the wind duct structure and continuously acts on the surface of the piezoelectric sensing element of the sensor device. c: Signal conversion step: The flexible piezoelectric film of the piezoelectric sensing element undergoes mechanical deformation due to the wind pressure generated by the directional airflow, and based on its positive piezoelectric effect, an original charge signal proportional to the deformation is generated between the first and second electrode layers. d: Signal conditioning steps: The original charge signal is processed sequentially by the signal amplification unit and the signal filtering unit in the signal conditioning device, and converted into a stable analog voltage signal with amplitude enhancement and noise removal; e: Data acquisition and processing steps: The controller performs analog-to-digital conversion on the analog voltage signal through its signal acquisition input terminal to obtain a digitized voltage sample value, and calculates and converts the digitized voltage sample value into the final wind pressure value according to the calibration model algorithm preset in the controller. f: Result output steps: The controller sends the calculated wind pressure value to the display unit for real-time display via the internal data bus, or sends it to an external device via the external communication interface.

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