A resonance frequency testing system for piezoelectric buzzer

Abstract

This invention discloses a resonant frequency testing system for piezoelectric buzzers, relating to the field of electrical variable measurement technology. The system includes applying a sweep frequency electrical signal to the piezoelectric buzzer under test; converting the acquired analog signal into a digital signal; identifying resonant characteristic electrical parameter points; and coordinating the working timing of each module. This invention achieves high-precision and high-efficiency measurement of the electrical characteristics of piezoelectric buzzers, improving the accuracy, repeatability, anti-interference capability, and throughput efficiency of the test, meeting the stringent requirements of modern intelligent manufacturing for high-frequency, high-consistency electrical variable measurement of piezoelectric buzzers.

Description

Technical Field

[0001] This invention relates to the field of electrical variable measurement technology, and in particular to a resonant frequency testing system for piezoelectric buzzers. Background Technology

[0002] With the rapid development of the Internet of Things, smart terminals, and consumer electronics, piezoelectric buzzers, as key sound output components, are widely used in alarms, smart homes, wearable devices, and automotive electronics. The market demands increasingly higher standards for product performance consistency, reliability, and production efficiency. The resonant frequency of the piezoelectric buzzer directly determines its sound production efficiency and sound quality, making it one of the core parameters for evaluating its quality. Therefore, rapid, accurate, and automated electrical measurement of the resonant frequency of piezoelectric buzzers has become an indispensable technical requirement in the manufacturing and quality inspection of electronic components.

[0003] However, current technologies for testing the resonant frequency of piezoelectric buzzers largely rely on manual operation or general impedance analyzers, resulting in low testing efficiency, poor repeatability, and susceptibility to environmental interference. While some simple test circuits can roughly determine the resonant point, they lack the ability to accurately acquire and analyze electrical variables such as impedance phase and amplitude, making it difficult to meet the requirements of high-precision sorting and batch automated testing. Furthermore, existing systems are often not specifically optimized for the electrical characteristics of piezoelectric buzzers, leading to insufficient stability of test results and failing to effectively support the high-precision measurement needs of modern intelligent manufacturing for electrical variables. Summary of the Invention

[0004] In view of the problems existing in the resonant frequency testing system for piezoelectric buzzers, this invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is that the existing piezoelectric buzzer resonant frequency testing method has technical defects such as low degree of automation, insufficient accuracy of electrical variable measurement, weak anti-interference ability, and difficulty in meeting the requirements of high consistency batch testing.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, embodiments of the present invention provide a resonant frequency testing system for a piezoelectric buzzer, comprising a signal excitation module for applying a sweep frequency electrical signal to the piezoelectric buzzer under test; The signal acquisition module is used to connect the two ends of the piezoelectric buzzer, acquire the analog signal of the piezoelectric buzzer under test under frequency sweep excitation, and convert the acquired analog signal into a digital signal. The data processing module is used to communicate with the signal acquisition module, calculate the complex impedance parameters of the piezoelectric buzzer at each frequency point based on the digital signal, and determine the resonant frequency by identifying the resonant characteristic electrical parameter points. The automatic control module is used to couple with the signal excitation module, signal acquisition module and data processing module respectively, coordinate the working sequence of each module, and complete the fully automated operation from the pre-test operation process to the determination of the resonance frequency.

[0007] As a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the signal excitation module includes a sweep frequency signal generation submodule, a signal conditioning submodule, and a power drive submodule. The frequency sweep signal generation submodule is used to generate a digital frequency sweep electrical signal sequence according to a preset frequency range and scanning step size. The frequency sweep electrical signal sequence covers the resonant frequency band of the piezoelectric buzzer. The signal conditioning submodule is connected to the sweep frequency signal generation submodule to perform excitation signal preprocessing on the generated digital sweep frequency electrical signal sequence, output an analog sweep frequency voltage signal, and suppress high-frequency spurious components in the analog sweep frequency voltage signal. The power drive submodule is used to connect with the signal conditioning submodule and is coupled to the piezoelectric buzzer under test through the output port to adapt the analog sweep voltage signal to the drive signal.

[0008] As a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the signal acquisition module includes a differential sensing submodule, a signal isolation submodule, and a high-precision analog-to-digital conversion submodule. The analog signal includes a voltage response signal and a current response signal; The differential sensing submodule is used to connect the two ends of the piezoelectric buzzer under test, and synchronously pick up the voltage response signal and current response signal under frequency sweep excitation in a differential manner, suppressing common-mode noise and retaining the complete dynamic range of analog signals. The signal isolation submodule is used to connect with the differential sensing submodule to perform signal isolation buffering on the picked-up voltage response signal and current response signal; The high-precision analog-to-digital converter submodule is used to connect with the signal isolation submodule to synchronously sample and quantize the isolated voltage response signal and current response signal. It adopts an analog-to-digital converter architecture to complete time-aligned dual-channel digital signal output within the full frequency sweep range.

[0009] As a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the data processing module includes a complex impedance calculation submodule, a resonant characteristic identification submodule, and a frequency determination submodule. The complex impedance calculation submodule is used to communicate with the signal acquisition module, receive the time-aligned dual-channel digital signal output, and obtain the complex impedance parameters of the piezoelectric buzzer at this frequency based on the voltage response signal and current response signal corresponding to each frequency point, forming frequency domain impedance spectrum data. The resonance feature identification submodule is used to connect with the complex impedance calculation submodule to scan and analyze the frequency domain impedance spectrum data, identify resonance feature electrical parameter points in the frequency domain impedance spectrum data that meet preset criteria, and locate candidate resonance frequency points. The frequency determination submodule is connected to the resonance feature recognition submodule to make resonance point decisions for candidate resonance frequency points, determine the main resonance frequency by combining the prior resonance features of the device, and output the value of the main resonance frequency as the test result.

[0010] As a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the automatic control module includes a timing scheduling submodule, a process status management submodule, and a multi-channel collaborative control submodule. The timing scheduling submodule is coupled to the signal excitation module, signal acquisition module and data processing module respectively. According to the test process logic, it generates and distributes trigger and synchronization instructions, and controls the start and end times of the sweep frequency signal, the start window of signal acquisition and the calculation timing of data processing in the sweep frequency signal generation submodule. The process status management submodule is used to connect with the timing scheduling submodule to monitor the execution status of each stage in the pre-test operation process in real time, and dynamically adjust the triggering conditions of subsequent operation processes based on status feedback to complete state-driven control. The multi-channel collaborative control submodule is used to connect with the process status management submodule and is simultaneously coupled to the parallel signal excitation module, signal acquisition module and data processing module. Within a single test cycle, it coordinates the independent test channels of the piezoelectric buzzer under test and manages the channel collaborative control elements of each independent test channel.

[0011] As a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the pre-test operation process includes material loading detection, electrical connection self-test, and excitation readiness confirmation. The loading detection is used to determine whether the piezoelectric buzzer is in place; the electrical connection self-test is used to verify the electrical connection status between the test fixture and the buzzer through the differential sensing submodule and the high-precision analog-to-digital conversion submodule; the excitation readiness confirmation is used by the power drive submodule to feedback the impedance matching and drive circuit status. When these are completed sequentially and confirmed by the process status management submodule, the timing scheduling submodule will then start the frequency sweep excitation.

[0012] In a preferred embodiment of the resonant frequency testing system for piezoelectric buzzers described in this invention, the complex impedance parameter is used for communication connection with the signal acquisition module to receive the time-aligned dual-channel digital signal output, based on the voltage response signal corresponding to each frequency point. With current response signal The formula for calculating the complex impedance parameter is: ; in, Represents the complex impedance parameter. Indicates the voltage response signal. This represents the current response signal.

[0013] Secondly, embodiments of the present invention provide a method for testing the resonant frequency of a piezoelectric buzzer, comprising: applying a sweep frequency electrical signal to the piezoelectric buzzer under test; connecting both ends of the piezoelectric buzzer, acquiring the analog signal of the piezoelectric buzzer under test under sweep frequency excitation, and converting the acquired analog signal into a digital signal; communicating with a signal acquisition module, calculating the complex impedance parameters of the piezoelectric buzzer at each frequency point based on the digital signal, and determining the resonant frequency by identifying the resonant characteristic electrical parameter points; and coupling with a signal excitation module, a signal acquisition module, and a data processing module respectively, coordinating the working timing of each module, and completing the fully automated operation from the pre-test operation process to the resonant frequency determination.

[0014] Thirdly, embodiments of the present invention provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any of the steps of the above-described resonant frequency testing system for piezoelectric buzzers.

[0015] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any of the steps of the above-described resonant frequency testing system for piezoelectric buzzers.

[0016] The beneficial effects of this invention are as follows: By constructing an integrated and automated resonant frequency testing system, this invention achieves high-precision and high-efficiency measurement of the electrical characteristics of piezoelectric buzzers. The signal excitation module can generate a sweep frequency electrical signal covering its resonant frequency band, and after excitation signal preprocessing and drive signal adaptation, it ensures stable and reliable excitation. The signal acquisition module adopts differential sensing, signal isolation buffering, and high-precision synchronous analog-to-digital conversion to effectively suppress noise and completely retain the amplitude and phase information of voltage and current response. The data processing module accurately obtains the complex impedance parameters at each frequency point based on the complex impedance calculation formula, and accurately determines the main resonant frequency by identifying the resonant characteristic electrical parameter points and combining them with the device's resonant prior characteristics. The automatic control module coordinates the timing of each sub-module to achieve closed-loop automation of the entire process from material loading detection, electrical connection self-test, excitation readiness confirmation to frequency determination, and supports multi-channel parallel testing. The overall solution significantly improves the accuracy, repeatability, anti-interference capability, and throughput efficiency of the test, meeting the stringent requirements of modern intelligent manufacturing for high-frequency, high-consistency electrical variable measurement of piezoelectric buzzers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of a resonant frequency testing system for a piezoelectric buzzer provided in an embodiment of the present invention.

[0018] Figure 2 This is a flowchart of a method for testing the resonant frequency of a piezoelectric buzzer, provided as an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the trend of impedance amplitude and phase of a piezoelectric buzzer as a function of frequency in a resonant frequency testing system for a piezoelectric buzzer, provided as an embodiment of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0023] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0024] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example Reference Figure 1 and Figure 2 This is the first embodiment of the present invention, which provides a resonant frequency testing system for a piezoelectric buzzer, comprising: S1: Signal excitation module, used to apply a sweep frequency electrical signal to the piezoelectric buzzer under test.

[0027] The signal excitation module includes a sweep frequency signal generation submodule, a signal conditioning submodule, and a power drive submodule. The frequency sweep signal generation submodule is used to generate a digital frequency sweep electrical signal sequence based on a preset frequency range and scanning step size. The frequency sweep electrical signal sequence covers the resonant frequency band of the piezoelectric buzzer. The signal conditioning submodule is connected to the sweep frequency signal generation submodule to perform excitation signal preprocessing on the generated digital sweep frequency electrical signal sequence, output an analog sweep frequency voltage signal, and suppress high-frequency spurious components in the analog sweep frequency voltage signal. The power drive submodule is used to connect with the signal conditioning submodule and is coupled to the piezoelectric buzzer under test through the output port to adapt the analog sweep voltage signal to the drive signal.

[0028] Furthermore, the signal excitation module consists of three sequentially connected sub-modules, forming a complete sweep frequency excitation signal generation and output link. First, the sweep frequency signal generation sub-module synthesizes a sweep frequency electrical signal sequence covering the typical resonant frequency band of the piezoelectric buzzer in the digital domain according to the user-defined frequency start and end range and scan step size, ensuring that the excitation signal can completely excite its resonant response. Subsequently, this digital sequence is sent to the signal conditioning sub-module for excitation signal preprocessing operations such as digital-to-analog conversion, waveform smoothing, and amplitude normalization to output a continuous, low-distortion, and spectrally pure analog sweep frequency voltage signal, effectively suppressing the interference of high-frequency spurious components on the test accuracy. Finally, the conditioned analog signal enters the power drive sub-module, where impedance matching and power amplification are used to adapt the drive signal, giving it sufficient driving capability to overcome the parasitic effects introduced by the test fixture and leads, while maintaining the consistency of the excitation amplitude across the entire frequency band, and finally applying it stably and controllably to both ends of the piezoelectric buzzer under test.

[0029] Furthermore, and more specifically, the signal excitation modules work collaboratively in a pipeline manner: the sweep frequency signal generation submodule first generates a high-resolution sweep frequency electrical signal sequence point-by-point in the digital domain based on the typical resonant frequency range of the piezoelectric buzzer, such as 2kHz to 6kHz, and a preset fine sweep step size, such as 10Hz; this sequence is then sent to the signal conditioning submodule, which first converts it into an analog signal through a high-precision digital-to-analog converter, and then performs waveform smoothing through low-pass filtering to eliminate the step effect or high-frequency glitches caused by discrete sampling. At the same time, the signal amplitude is normalized through an automatic gain control circuit to ensure the signal is delivered smoothly throughout the entire sweep frequency process. The output voltage amplitude remains constant. The conditioned high-quality analog sweep signal then enters the power drive submodule, which has a built-in wideband power amplifier and an adjustable output impedance network. On the one hand, it boosts the signal power to a level sufficient to drive the piezoelectric buzzer and overcomes the influence of parasitic parameters such as test fixture contact resistance and lead inductance. On the other hand, it adapts the output impedance of the signal source to the input impedance of the device under test through real-time impedance matching, minimizing signal reflection and energy loss. This provides a stable, pure, amplitude-consistent, and sufficiently powerful sweep excitation signal to the piezoelectric buzzer throughout the entire frequency band, laying a reliable excitation foundation for subsequent high-precision resonant frequency measurement.

[0030] S2: Signal acquisition module, used to connect the two ends of the piezoelectric buzzer, acquire the analog signal of the piezoelectric buzzer under frequency sweep excitation, and convert the acquired analog signal into a digital signal.

[0031] The signal acquisition module includes a differential sensing submodule, a signal isolation submodule, and a high-precision analog-to-digital conversion submodule. Analog signals include voltage response signals and current response signals; The differential sensing submodule is used to connect the two ends of the piezoelectric buzzer under test, and synchronously pick up the voltage response signal and current response signal under frequency sweep excitation in a differential manner, suppressing common-mode noise and retaining the complete dynamic range of analog signals. The signal isolation submodule is used to connect with the differential sensing submodule to perform signal isolation and buffering on the picked-up voltage response signal and current response signal; The high-precision analog-to-digital converter submodule is used to connect with the signal isolation submodule to synchronously sample and quantize the isolated voltage response signal and current response signal. It adopts an analog-to-digital converter architecture to complete time-aligned dual-channel digital signal output across the full frequency sweep range.

[0032] Furthermore, the signal acquisition module employs a three-stage cascaded architecture to ensure high-fidelity acquisition of the weak electrical response signal of the piezoelectric buzzer under frequency sweep excitation. First, the differential sensing submodule is directly connected to the two electrodes of the piezoelectric buzzer under test. A high-input-impedance differential amplifier circuit synchronously picks up the voltage response signal across its terminals, and a precision sampling resistor is connected in series in the loop to indirectly acquire the corresponding current response signal. The differential structure naturally suppresses environmental common-mode interference, such as power supply noise and electromagnetic coupling, while preserving the original dynamic range and phase relationship of the signal to the maximum extent. Subsequently, the two acquired analog signals enter the signal isolation submodule. This submodule uses a high-performance analog isolator or linear optocoupler technology to electrically isolate and impedance-buffer the voltage and current signals respectively, effectively disconnecting the test system from the device under test. The ground loop between the two channels prevents external interference from being injected in reverse or affecting the working state of the buzzer, and also converts the high-impedance signal into a low-impedance output, improving the ability to drive subsequent circuits. Finally, the two analog signals after isolation and buffering are sent to the high-precision analog-to-digital converter submodule. This submodule integrates a dual-channel synchronous sampling analog-to-digital converter, which performs parallel quantization of voltage and current signals with a strictly consistent sampling clock throughout the entire frequency sweep cycle, ensuring that the two are completely aligned on the time axis and avoiding phase errors introduced by sampling offset. The final output is a high-resolution, high-signal-to-noise ratio, and strictly synchronized dual-channel digital signal, providing an accurate and reliable raw data foundation for subsequent complex impedance calculations.

[0033] S3: Data processing module, used to communicate with the signal acquisition module, calculate the complex impedance parameters of the piezoelectric buzzer at each frequency point based on digital signals, and determine the resonant frequency by identifying the resonant characteristic electrical parameter points.

[0034] The data processing module includes a complex impedance calculation submodule, a resonance characteristic identification submodule, and a frequency determination submodule. The complex impedance calculation submodule is used to communicate with the signal acquisition module, receive the time-aligned dual-channel digital signal output, and obtain the complex impedance parameters of the piezoelectric buzzer at this frequency based on the voltage response signal and current response signal corresponding to each frequency point, forming frequency domain impedance spectrum data. The resonance feature identification submodule is used to connect with the complex impedance calculation submodule to scan and analyze the frequency domain impedance spectrum data, identify the resonance feature electrical parameter points in the frequency domain impedance spectrum data that meet the preset criteria, and locate the candidate resonance frequency points. The frequency determination submodule is connected to the resonance feature identification submodule to make resonance point decisions for candidate resonance frequency points. Combining the prior resonance features of the device, it determines the main resonance frequency and outputs the value of the main resonance frequency as the test result.

[0035] Furthermore, the data processing module adopts a phased, progressive data analysis architecture to accurately extract the resonant frequency of the piezoelectric buzzer. First, the complex impedance calculation submodule receives time-aligned dual-channel digital signals from the signal acquisition module, corresponding to the voltage and current responses at each frequency sweep point. Based on the amplitude and phase relationship of these signals at each frequency point, it calculates the corresponding complex impedance parameters point by point and integrates the impedance results of all frequency points into a complete frequency domain impedance spectrum, clearly presenting the continuous characteristics of impedance change with frequency. Next, the resonance feature identification submodule scans this impedance spectrum. Based on preset physical criteria, such as the position where the impedance phase changes from positive to negative and crosses zero, or the frequency point where the impedance amplitude reaches a local minimum, it automatically identifies one or more candidate frequency points that meet the characteristics of resonance behavior as potential resonance locations. Finally, the frequency determination submodule, combined with the prior resonance characteristics of the piezoelectric buzzer, including the typical resonant frequency range and the expected impedance change trend, performs logical verification and priority evaluation on all candidate points, eliminating false peaks caused by noise, parasitic resonance, or measurement anomalies. Ultimately, it determines a unique, stable, and physically meaningful main resonant frequency and outputs its value as the test result, thus achieving a complete closed-loop process from the original electrical response signal to high-reliability resonant frequency determination.

[0036] Preferably, in actual testing, the system swept the frequency of a certain type of piezoelectric buzzer in the range of 2.0kHz to 6.0kHz with a step size of 10Hz. After the complex impedance calculation submodule generated a complete frequency domain impedance spectrum, the resonance characteristic identification submodule found a significant impedance valley at 3.842kHz. At the same time, the impedance phase near this frequency point changed from positive to negative, which is consistent with the characteristics of series resonance. Combined with the known typical operating frequency band of the device, 3.5kHz to 4.2kHz, the frequency determination submodule ruled out other non-main resonance points such as 4.915kHz. Finally, the main resonance frequency was output as 3.842kHz. After 50 repeated tests, the standard deviation of the result was less than 0.015kHz, which verified the high stability and accuracy of the system.

[0037] Furthermore, the data processing module achieves highly robust resonance frequency determination through three tightly interconnected logic units: The complex impedance calculation submodule first performs frequency-by-frequency analysis on the strictly time-synchronized dual-channel digital signals of voltage and current output from the signal acquisition module. At each swept frequency, based on the instantaneous amplitude ratio and phase difference relationship between the two signals, it accurately constructs the complex impedance value corresponding to that frequency and organizes the complex impedance results of all frequency points into a continuous and smooth frequency domain impedance spectrum feature, fully reflecting the electrical response characteristics of the piezoelectric buzzer throughout the entire excitation frequency band. Subsequently, the resonance feature identification submodule performs a refined scanning analysis of this impedance spectrum, not only detecting local minima in the impedance amplitude feature corresponding to series resonance, but also synchronously tracking the impedance phase feature as it crosses zero degrees from positive to negative or from negative to positive. The zero-crossing point corresponds to the voltage and current being in phase at resonance. Frequency points that simultaneously satisfy both amplitude and phase characteristics are marked as high-confidence candidate resonance points, while those that only satisfy a single condition are marked as low-priority candidate points. Finally, the frequency determination submodule calls the pre-stored device resonance prior feature library, including the standard resonance frequency range of this model of piezoelectric buzzer, the impedance sharpness corresponding to typical Q values, and the morphological template of amplitude and phase changes during normal resonance. All candidate points are cross-validated in multiple dimensions, and interference points that fall in atypical frequency bands, have abnormal phase jumps, or have amplitude valley widths that do not meet expectations are eliminated. Finally, the frequency point that best conforms to physical laws and is consistent with historical data is selected from the remaining valid points as the main resonance frequency, and output in high-precision numerical form to ensure that the test results are accurate and have good repeatability and engineering applicability.

[0038] S4: Automatic control module, which is used to couple with the signal excitation module, signal acquisition module and data processing module respectively, coordinate the working sequence of each module, and complete the fully automated operation from the pre-test operation process to the determination of the resonance frequency.

[0039] The automatic control module includes a timing scheduling submodule, a process status management submodule, and a multi-channel collaborative control submodule. The timing scheduling submodule is used to couple with the signal excitation module, signal acquisition module and data processing module respectively. According to the test process logic, it generates and distributes trigger and synchronization instructions, and controls the start and end times of the sweep frequency signal, the start window of signal acquisition and the calculation timing of data processing in the sweep frequency signal generation submodule. The process status management submodule is used to connect with the timing scheduling submodule to monitor the execution status of each stage in the pre-test operation process in real time, and dynamically adjust the triggering conditions of subsequent operation processes based on status feedback to complete state-driven control. The multi-channel collaborative control submodule is used to connect with the process status management submodule and simultaneously couple to the parallel signal excitation module, signal acquisition module, and data processing module. Within a single test cycle, it coordinates the independent test channels of the piezoelectric buzzer under test and manages the channel collaborative control elements of each independent test channel.

[0040] Furthermore, the automatic control module adopts a three-layer collaborative architecture to achieve precise, flexible, and efficient control over the entire testing process. The timing scheduling submodule, acting as the system's time hub, generates high-precision trigger and synchronization command sequences based on the preset test process logic. These sequences are then distributed to the signal excitation module, signal acquisition module, and data processing module, precisely controlling the start and end times of the frequency sweep signal, the opening and closing of the signal acquisition window, and the start node of the data processing task. This ensures strict alignment of all functional modules on the timeline, avoiding data distortion or measurement errors caused by operational misalignment. The process status management submodule, acting as the system's status perception and decision-making unit, receives real-time status feedback signals from the loading mechanism, electrical connection detection circuit, and various functional submodules. It dynamically determines the current pre-test operation process, such as loading completion and electrical connection self-test pass. The system checks whether conditions for proceeding to the next stage are met, such as whether the signal excitation is ready, and issues instructions to the timing scheduling submodule to allow or delay execution, forming a control mechanism driven by the actual hardware state, which effectively improves the system's robustness. On this basis, the multi-channel collaborative control submodule is responsible for expanding the system's parallel processing capabilities. It connects multiple independently configured signal excitation, signal acquisition, and data processing channels simultaneously. Within a single test cycle, it performs unified scheduling and isolation management of the test progress, resource usage, and data flow path of each channel, ensuring that multiple piezoelectric buzzers can complete the entire process test synchronously and without interference. This significantly improves the overall test throughput while ensuring the measurement accuracy of a single channel, meeting the needs of industrial batch testing.

[0041] Furthermore, the automatic control module, through deep integration of the timing scheduling submodule, process status management submodule, and multi-channel collaborative control submodule, constructs an intelligent control system that combines time accuracy, state adaptability, and parallel scalability. The timing scheduling submodule generates and distributes synchronization commands with microsecond-level precision: after confirming system readiness, it first triggers the frequency sweep signal generation submodule to start outputting excitation signals, while simultaneously setting a slightly delayed but strictly aligned acquisition start window to ensure that the signal acquisition module only begins sampling after the excitation has stabilized. Subsequently, at the instant acquisition is completed, it notifies the data processing module to start complex impedance calculation, forming a seamless pipeline operation of excitation, acquisition, and processing. The process status management submodule runs throughout the entire pre-test operation process, continuously monitoring key status indicators such as whether the loading sensor detects the device's arrival, whether the differential sensing submodule reports valid connection impedance, and whether the power drive submodule reports normal output stage status. Only when all preconditions are met does it send a start-allow signal to the timing scheduling submodule; if any link fails to meet these conditions, the system will not allow the device to start. Normally, if there is poor contact or missing components, the process is paused and the fault status is recorded to avoid invalid or erroneous tests. On this basis, the multi-channel collaborative control submodule assigns an independent logic control unit to each physical test channel and maintains a global channel status table to track the stage of each channel in real time, such as waiting for loading, being stimulated, data processing, and completed. It dynamically allocates shared resources, such as processor bandwidth and storage buffer, and ensures that the data flow and control signals of each channel do not interfere with each other through hardware isolation mechanisms. This allows multiple piezoelectric buzzers to undergo the complete loading, self-test, stimulation, acquisition, and judgment process in parallel within the same test cycle. This maintains the high precision characteristics of single-channel measurement and achieves a linear improvement in test efficiency, fully supporting the needs of high-capacity and high-consistency industrial automated production.

[0042] Preferably, the pre-test operation process includes material loading detection, electrical connection self-test, and excitation readiness confirmation; The loading detection is used to determine whether the piezoelectric buzzer is in place; the electrical connection self-test is used to verify the electrical connection status between the test fixture and the buzzer through the differential sensing submodule and the high-precision analog-to-digital conversion submodule; the excitation readiness confirmation is used by the power drive submodule to feedback the impedance matching and drive circuit status. When these are completed in sequence and confirmed by the process status management submodule, the timing scheduling submodule will start the frequency sweep excitation.

[0043] The complex impedance parameter is used for communication with the signal acquisition module to receive the time-aligned dual-channel digital signal output, based on the voltage response signal corresponding to each frequency point. The formula for calculating the complex impedance parameters, in relation to the current response signal, is as follows: ; in, Represents the complex impedance parameter. Indicates the voltage response signal. This represents the current response signal.

[0044] Furthermore, to ensure the reliability of the testing process and the validity of the data, the system strictly adheres to a pre-test operation procedure consisting of three stages: material loading detection, electrical connection self-test, and excitation readiness confirmation, before formally applying the frequency sweep excitation. First, the material loading detection uses photoelectric switches or position sensors to determine whether the piezoelectric buzzer is accurately placed at the test station; if not, subsequent operations are prohibited. Second, the electrical connection self-test involves the differential sensing submodule applying a weak detection signal to both ends of the buzzer, and the high-precision analog-to-digital conversion submodule reads back the response, analyzing the loop impedance to determine if there are any abnormal connection states such as loose connections, open circuits, or short circuits between the test fixture and the buzzer electrodes. Subsequently, in the excitation readiness confirmation stage, the power drive submodule performs a self-test on the operating status of its internal drive circuit and the impedance matching of its output ports, feeding the results back to the control system. Only when the above three steps are successfully completed in sequence, and the process status management submodule confirms that all preconditions are met, does it send a permission signal to the timing scheduling submodule, triggering the formal start of the frequency sweep excitation. Based on this, the time-aligned dual-channel digital signals of voltage and current acquired by the signal acquisition module are sent to the data processing module to calculate the complex impedance parameters at each frequency point, thereby constructing a complete frequency domain impedance spectrum and providing a high-fidelity, highly consistent raw data foundation for subsequent accurate identification of the resonant frequency.

[0045] Furthermore, before initiating the formal frequency sweep test, the system uses a closed-loop verification mechanism to verify the physical and electrical status of the test link step by step, ensuring that subsequent measurements are based on reliability. First, during the material loading and inspection phase, the test station is equipped with a high-sensitivity photoelectric sensor or mechanical contact switch to detect in real time whether the piezoelectric buzzer is completely and correctly embedded in the fixture. If no device is detected or the position is offset, the process status management submodule immediately locks the subsequent process and can trigger an alarm or replenishment command. Next, the electrical connection self-test phase begins. At this time, the differential sensing submodule does not apply the main excitation signal but outputs a low-amplitude, low-frequency safety detection signal. The high-precision analog-to-digital conversion submodule synchronously acquires the voltage and current response in the circuit. Based on this, the system determines whether a stable connection is formed between the two poles of the buzzer and the test probe. If the impedance is abnormally high, it is determined to be a loose connection or open circuit. If the impedance is close to zero, it is considered a short circuit. Any abnormality will cause the self-test to fail and the process to terminate. Then, the excitation readiness confirmation stage begins. The power drive submodule performs internal self-tests on its own power supply, amplifier bias, output protection circuit, and impedance matching network with the load port to confirm that there are no overheating, overcurrent, or open circuit faults, and to verify that its output stage is in a normal driving state. It then feeds back the readiness or fault status code to the process status management submodule. Only when all three stages return to a successful state and the process status management submodule completes the logic verification will it send a start-up permission command to the timing scheduling submodule. The latter then precisely triggers the frequency sweep signal generation, synchronous acquisition, and data processing process according to the preset timing. Thus, the entire system achieves pre-emptive protection in three dimensions: physical clamping, electrical connectivity, and excitation capability. This ensures that the acquired voltage and current dual-channel digital signals accurately reflect the electrical characteristics of the piezoelectric buzzer under test, providing a solid and reliable data foundation for subsequent high-precision complex impedance calculation and resonant frequency determination.

[0046] Preferably, in the actual verification experiment of this invention, a batch of 100 piezoelectric buzzers of the same model were tested for resonant frequency. The system was set with a sweep frequency range of 2.5kHz to 5.5kHz, a sweep step size of 5Hz, and a constant excitation voltage amplitude of 5Vrms. The test results showed that the main resonant frequencies of all samples were concentrated between 4.120kHz and 4.185kHz, with an average value of 4.152kHz and a standard deviation of only 0.018kHz, indicating good repeatability. The maximum deviation of a single device in 10 consecutive tests did not exceed ±0.012kHz. Furthermore, comparison tests with a high-precision impedance analyzer showed that the measured resonant frequency deviation was less than 0.03%, fully verifying the advantages of this invention in terms of accuracy, stability, and engineering practicality.

[0047] In a preferred embodiment, a method for testing the resonant frequency of a piezoelectric buzzer includes: applying a sweep frequency electrical signal to the piezoelectric buzzer under test; connecting both ends of the piezoelectric buzzer to acquire the analog signal of the piezoelectric buzzer under sweep frequency excitation and converting the acquired analog signal into a digital signal; communicating with a signal acquisition module to calculate the complex impedance parameters of the piezoelectric buzzer at each frequency point based on the digital signal, and determining the resonant frequency by identifying the resonant characteristic electrical parameter points; and coupling with a signal excitation module, a signal acquisition module, and a data processing module respectively to coordinate the working timing of each module and complete the fully automated operation from the pre-test operation process to the resonant frequency determination.

[0048] The above-mentioned unit modules can be embedded in the processor of the computer device in hardware form or independent of it, or they can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of the above modules.

[0049] In one embodiment, a computer device is provided, which may be a terminal. The computer device includes a processor, memory, a communication interface, a display screen, and an input device connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The communication interface of the computer device is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen of the computer device may be an LCD screen or an e-ink display screen. The input device of the computer device may be a touch layer covering the display screen, or buttons, a trackball, or a touchpad located on the casing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0050] In summary, this invention achieves high-precision and high-efficiency measurement of the electrical characteristics of piezoelectric buzzers by constructing an integrated and automated resonant frequency testing system. The signal excitation module generates a sweep frequency electrical signal covering the resonant frequency band, and ensures stable and reliable excitation through excitation signal preprocessing and drive signal adaptation. The signal acquisition module uses differential sensing, signal isolation buffering, and high-precision synchronous analog-to-digital conversion to effectively suppress noise and completely retain the amplitude and phase information of voltage and current responses. The data processing module accurately obtains the complex impedance parameters at each frequency point based on the complex impedance calculation formula, and accurately determines the main resonant frequency by identifying the resonant characteristic electrical parameter points and combining them with the device's resonant prior characteristics. The automatic control module coordinates the timing of each sub-module to achieve closed-loop automation of the entire process from material loading detection, electrical connection self-test, excitation readiness confirmation to frequency determination, and supports multi-channel parallel testing. The overall solution significantly improves the accuracy, repeatability, anti-interference capability, and throughput efficiency of the test, meeting the stringent requirements of modern intelligent manufacturing for high-frequency, high-consistency electrical variable measurement of piezoelectric buzzers.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A resonant frequency testing system for piezoelectric buzzer, characterized in that: include, The signal excitation module is used to apply a sweep frequency electrical signal to the piezoelectric buzzer under test; The signal acquisition module is used to connect the two ends of the piezoelectric buzzer, acquire the analog signal of the piezoelectric buzzer under test under frequency sweep excitation, and convert the acquired analog signal into a digital signal. The data processing module is used to communicate with the signal acquisition module, calculate the complex impedance parameters of the piezoelectric buzzer at each frequency point based on the digital signal, and determine the resonant frequency by identifying the resonant characteristic electrical parameter points. The automatic control module is used to couple with the signal excitation module, signal acquisition module and data processing module respectively, coordinate the working sequence of each module, and complete the fully automated operation from the pre-test operation process to the determination of the resonance frequency.

2. The resonant frequency testing system for piezoelectric buzzer sheet as claimed in claim 1, wherein: The signal excitation module includes a frequency sweep signal generation submodule, a signal conditioning submodule, and a power drive submodule; The frequency sweep signal generation submodule is used to generate a digital frequency sweep electrical signal sequence according to a preset frequency range and scanning step size. The frequency sweep electrical signal sequence covers the resonant frequency band of the piezoelectric buzzer. The signal conditioning submodule is connected to the sweep frequency signal generation submodule to perform excitation signal preprocessing on the generated digital sweep frequency electrical signal sequence, output an analog sweep frequency voltage signal, and suppress high-frequency spurious components in the analog sweep frequency voltage signal. The power drive submodule is used to connect with the signal conditioning submodule and is coupled to the piezoelectric buzzer under test through the output port to adapt the analog sweep voltage signal to the drive signal.

3. The resonant frequency testing system for piezoelectric buzzer sheet as claimed in claim 2, wherein: The signal acquisition module includes a differential sensing submodule, a signal isolation submodule, and a high-precision analog-to-digital conversion submodule; The analog signal includes a voltage response signal and a current response signal; The differential sensing submodule is used to connect the two ends of the piezoelectric buzzer under test, and synchronously pick up the voltage response signal and current response signal under frequency sweep excitation in a differential manner, suppressing common-mode noise and retaining the complete dynamic range of analog signals. The signal isolation submodule is used to connect with the differential sensing submodule to perform signal isolation buffering on the picked-up voltage response signal and current response signal; The high-precision analog-to-digital converter submodule is used to connect with the signal isolation submodule to synchronously sample and quantize the isolated voltage response signal and current response signal. It adopts an analog-to-digital converter architecture to complete time-aligned dual-channel digital signal output within the full frequency sweep range.

4. The resonant frequency testing system for piezoelectric buzzer sheet as claimed in claim 3, wherein: The data processing module includes a complex impedance calculation submodule, a resonance feature identification submodule, and a frequency determination submodule; The complex impedance calculation submodule is used to communicate with the signal acquisition module, receive the time-aligned dual-channel digital signal output, and obtain the complex impedance parameters of the piezoelectric buzzer at this frequency based on the voltage response signal and current response signal corresponding to each frequency point, forming frequency domain impedance spectrum data. The resonance feature identification submodule is used to connect with the complex impedance calculation submodule to scan and analyze the frequency domain impedance spectrum data, identify resonance feature electrical parameter points in the frequency domain impedance spectrum data that meet preset criteria, and locate candidate resonance frequency points. The frequency determination submodule is connected to the resonance feature recognition submodule to make resonance point decisions for candidate resonance frequency points, determine the main resonance frequency by combining the prior resonance features of the device, and output the value of the main resonance frequency as the test result.

5. The resonant frequency testing system for piezoelectric buzzers as described in claim 4, characterized in that: The automatic control module includes a timing scheduling submodule, a process status management submodule, and a multi-channel collaborative control submodule; The timing scheduling submodule is coupled to the signal excitation module, signal acquisition module and data processing module respectively. According to the test process logic, it generates and distributes trigger and synchronization instructions, and controls the start and end times of the sweep frequency signal, the start window of signal acquisition and the calculation timing of data processing in the sweep frequency signal generation submodule. The process status management submodule is used to connect with the timing scheduling submodule to monitor the execution status of each stage in the pre-test operation process in real time, and dynamically adjust the triggering conditions of subsequent operation processes based on status feedback to complete state-driven control. The multi-channel collaborative control submodule is used to connect with the process status management submodule and is simultaneously coupled to the parallel signal excitation module, signal acquisition module and data processing module. Within a single test cycle, it coordinates the independent test channels of the piezoelectric buzzer under test and manages the channel collaborative control elements of each independent test channel.

6. The resonant frequency testing system for piezoelectric buzzers as described in claim 5, characterized in that: The pre-test operation process includes material loading detection, electrical connection self-test, and excitation readiness confirmation. The loading detection is used to determine whether the piezoelectric buzzer is in place; the electrical connection self-test is used to verify the electrical connection status between the test fixture and the buzzer through the differential sensing submodule and the high-precision analog-to-digital conversion submodule; the excitation readiness confirmation is used by the power drive submodule to feedback the impedance matching and drive circuit status. When these are completed sequentially and confirmed by the process status management submodule, the timing scheduling submodule will then start the frequency sweep excitation.

7. The resonant frequency testing system for piezoelectric buzzers as described in claim 6, characterized in that: The complex impedance parameter is used for communication connection with the signal acquisition module to receive the time-aligned dual-channel digital signal output, based on the voltage response signal corresponding to each frequency point. With current response signal The formula for calculating the complex impedance parameter is: ; in, Represents the complex impedance parameter. Indicates the voltage response signal. This represents the current response signal.

8. A method for testing the resonant frequency of a piezoelectric buzzer, based on the resonant frequency testing system for a piezoelectric buzzer according to any one of claims 1 to 7, characterized in that: include, A sweep frequency electrical signal is applied to the piezoelectric buzzer under test; Connect the two ends of the piezoelectric buzzer, collect the analog signal of the piezoelectric buzzer under frequency sweep excitation, and convert the collected analog signal into a digital signal; It communicates with the signal acquisition module, calculates the complex impedance parameters of the piezoelectric buzzer at each frequency point based on digital signals, and determines the resonant frequency by identifying the resonant characteristic electrical parameter points; It is coupled to the signal excitation module, signal acquisition module and data processing module respectively, and coordinates the working timing of each module to complete the fully automated operation from the pre-test operation process to the determination of the resonance frequency.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the resonant frequency testing system for piezoelectric buzzers as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the resonant frequency testing system for piezoelectric buzzers as described in any one of claims 1 to 7.

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