Piezoelectric conversion collection system of piezoelectric ceramic vibration sensor

Abstract

The application discloses a piezoelectric conversion and collection system of a piezoelectric ceramic vibration sensor, which comprises a collection device and a conversion and processing system for the collection device, wherein the collection device and the conversion and processing system are combined into a composite through mechanical connection; the conversion and processing system is connected with an upper computer and the collection device through wired or wireless modes; a circuit unit is integrated in the collection device, and the circuit unit is integrated with a circuit for piezoelectric conversion of the sensor. The vibration sensor with the stacked piezoelectric ceramic as a sensitive element is used for integrated real-time data collection, data processing and data communication system design, interference signals generated in the vibration test process can be effectively processed, the vibration sensor is stable in work, millivolt-level measurement precision is achieved, and interference signals generated in the test process can be effectively suppressed.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric conversion technology, and more particularly to a piezoelectric conversion acquisition system for a piezoelectric ceramic vibration sensor. Background Technology

[0002] Piezoelectric ceramic vibration sensors are used in real-time vibration signal testing of suspension systems. With the rapid development of the automotive industry, the demands for smoothness, comfort, and handling stability during high-speed driving are increasing. Active suspension systems, with their superior vibration damping performance, employ active strategies to suppress vibrations caused by uneven road surfaces, and have become a typical feature of high-end vehicles. As a crucial real-time monitoring device for the suspension, the cost-effectiveness of the sensor directly impacts the control of active suspension development costs.

[0003] Considering the real-time vibration signal testing environment of the suspension, and the very small amount of charge generated by the piezoelectric ceramic material under pressure, the weak piezoelectric signal is processed by the conversion electronic circuit and sent to the industrial control computer. To monitor the physical information of the vibration signal in real time, distortion caused by unavoidable noise interference during signal processing will affect the effectiveness of the sensor. Therefore, the design requirements for its conversion electronic circuit are high, especially for the electronic circuit of the vibration sensing subsystem of the active vibration controller. This includes the design and verification of its input-output relationship in the time and frequency domains, as well as the verification of its accuracy, operating range, stability, precision, speed, anti-interference, and robustness, to ensure that it meets the design requirements of the active vibration controller.

[0004] However, for automotive suspensions, how to achieve real-time monitoring of vibration characteristics and how to handle the communication between piezoelectric signals and the CPU serial port to achieve high-precision monitoring, analysis, and effective anti-interference capabilities in both working and testing scenarios are urgent problems that need to be solved. Summary of the Invention

[0005] The purpose of this invention is to address the deficiencies in the existing technology by proposing a piezoelectric conversion acquisition system for a piezoelectric ceramic vibration sensor.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A piezoelectric conversion and acquisition system for a piezoelectric ceramic vibration sensor includes an acquisition device and a conversion and processing system for the acquisition device, wherein:

[0008] The acquisition device and the conversion and processing system are mechanically connected to form a composite component.

[0009] The conversion and processing system is connected to the host computer and the acquisition device via wired or wireless means, respectively.

[0010] The acquisition device integrates a circuit unit, which incorporates circuitry for the piezoelectric conversion of the sensor.

[0011] Furthermore, the conversion processing system includes: the stacked piezoelectric ceramic vibration sensor conversion processing system mainly consists of a vibration test excitation source module, a piezoelectric ceramic sensing module, a lower-level processing module, and an upper-level processing module.

[0012] Furthermore, the vibration test excitation source module is used to conduct vibration tests and analyses using a suspension mechanical model to obtain effective vibration sources;

[0013] The piezoelectric ceramic sensing module is used to acquire piezoelectric power signals, collect piezoelectric data, and output piezoelectric signals through circuit units;

[0014] The lower-level processing module is used to read piezoelectric signals and transmit data via serial port;

[0015] The host computer processing module is used to organize the data received from the serial port, analyze the data, and obtain the final piezoelectric conversion data.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] By designing an integrated real-time data acquisition, data processing, and data communication system using a vibration sensor with stacked piezoelectric ceramics as the sensing element, it is possible to effectively process interference signals generated during vibration testing. While maintaining stable operation, it can effectively suppress interference signals that occur during testing while achieving millivolt-level measurement accuracy. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0019] Figure 1 This is a schematic diagram of the acquisition device of the piezoelectric conversion acquisition system of the piezoelectric ceramic vibration sensor proposed in this invention;

[0020] Figure 2 This is a schematic diagram of the operation flow of the piezoelectric conversion and acquisition system of the piezoelectric ceramic vibration sensor proposed in this invention;

[0021] Figure 3 This is a schematic diagram of the conversion and processing system of the piezoelectric conversion and acquisition system of the piezoelectric ceramic vibration sensor proposed in this invention;

[0022] Figure 4 This is a schematic diagram of the electronic circuit in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the electronic circuit PCB in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the hardware circuit of the acquisition device in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of serial port data transmission processing in an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of data acquisition, processing, and analysis in an embodiment of the present invention. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] Reference Figure 1-3 A piezoelectric conversion and acquisition system for a piezoelectric ceramic vibration sensor includes an acquisition device and a conversion and processing system for the acquisition device, wherein:

[0029] The acquisition device and the conversion and processing system are mechanically connected to form a composite component.

[0030] The conversion and processing system is connected to the host computer and the acquisition device via wired or wireless means, respectively.

[0031] The acquisition device integrates a circuit unit, which incorporates circuitry for the piezoelectric conversion of the sensor.

[0032] In this embodiment, the acquisition device is connected to a piezoelectric ceramic sensor, and the piezoelectric ceramic sensor is installed on the vehicle suspension. The vibration signal of the suspension is detected by the signal acquisition device and converted into a digital signal by the circuit unit and conversion processing system.

[0033] The processing chip used in the acquisition device is STM32F405RGT6, and the acquisition device is equipped with various interfaces for data transmission between analog and digital circuits.

[0034] The circuit unit is used to excite and collect the suspension vibration signal, and transmit the real-time detected signal to the host computer for targeted analysis and processing through serial communication. The host computer is any terminal device that meets the function and has sufficient computing power, including but not limited to a PC. In this application, a PC is preferred.

[0035] In this application, the processed suspension vibration signal data is stably stored on a PC, and subsequently repeatedly accessed and analyzed using multiple digital signal processing methods.

[0036] like Figure 3 As shown, it is necessary to further explain that, because it is necessary to simulate millivolt-level vibrations to achieve vibrations at different frequencies, providing vibration sources for the sensor conversion and processing system, and the piezoelectric power supply signal needs to undergo amplification, filtering, AD conversion, nonlinear processing, and other steps, and the collected piezoelectric information needs to be transmitted to the host computer for analysis and processing, a 12-bit microcontroller is selected as the lower-level machine to process the collected data.

[0037] In the entire vibration signal acquisition system, to ensure that the system achieves its design goals of accuracy, stability, and speed, the performance of the designed conversion circuit must be tested to guarantee that the acquired signal accurately and objectively reproduces the piezoelectric signal. The overall design architecture's technical approach is as follows: Figure 3 As shown.

[0038] In a specific embodiment of this application, the circuit integrated by the circuit unit includes: an analog piezoelectric conversion circuit, a digital signal acquisition circuit, and a cooperative communication circuit.

[0039] In this embodiment, the piezoelectric signal received by the piezoelectric ceramic sensor is regarded as a series connection of a voltage source and an equivalent resistance. Therefore, the amplifier circuit is the load of this series circuit. When the input impedance of the amplifier circuit is high, the loss of the piezoelectric signal in the internal resistance is smaller.

[0040] An OPA333 voltage follower circuit was introduced before the signal entered the amplifier circuit, which improved the input impedance of the circuit and played a sufficient buffering and isolation role between each stage of the circuit, avoiding signal loss and improving the signal-to-noise ratio. Considering that the voltage point signal is weak, the AD623 operational amplifier chip was used to provide a sufficiently large gain to amplify it to a sufficient level.

[0041] In a specific embodiment of this application, the conversion processing system includes: a stacked piezoelectric ceramic vibration sensor conversion processing system mainly composed of a vibration test excitation source module, a piezoelectric ceramic sensing module, a lower-level processing module, and an upper-level processing module.

[0042] In a specific embodiment of this application, the vibration test excitation source module is used to perform vibration testing and analysis using a suspension mechanical model to obtain an effective vibration source;

[0043] The piezoelectric ceramic sensing module is used to acquire piezoelectric power signals, collect piezoelectric data, and output piezoelectric signals through circuit units;

[0044] The lower-level processing module is used to read piezoelectric signals and transmit data via serial port;

[0045] The host computer processing module is used to organize the data received from the serial port, analyze the data, and obtain the final piezoelectric conversion data.

[0046] In this embodiment, the test excitation source is a 500Hz sine wave with an amplitude of 40mV. After passing through analog circuits such as amplification and filtering, the signal is sent to the circuit unit for processing, and finally sent to the host computer for digital signal processing via the serial port of the acquisition device.

[0047] To better understand the technical solution of this application, the following description is provided in conjunction with the accompanying drawings.

[0048] like Figure 4 As shown, this invention uses an active Wien bridge circuit in conjunction with an LM358 dual operational amplifier chip to design a low-pass filter with a cutoff frequency of 1kHz, which suppresses power frequency noise and filters out large-amplitude noise components.

[0049] like Figure 5 As shown, in accordance with the requirements of piezoelectric signal acquisition by piezoelectric ceramic sensors, an analog circuit PCB with different types of amplifiers as the core is designed to amplify the acquired piezoelectric signals, filter out noise in the signals, and process power frequency interference.

[0050] like Figure 6 As shown, the software design uses STM32CUBEIDE software. In Clock Configuration, the clock frequency is configured to 168MHz. In Pinout & Configuration, the system single bus, ADC / DAC pin functions, timer parameters, and I2C parameters are set to standard mode and USART asynchronous mode, with a data rate of 115200 bits / s. When the excitation source triggers the sensor signal, this signal is processed by the analog circuit and input to the configured acquisition device ADC pin. The microcontroller detects the received signal, triggers an external interrupt, enables the ADC to acquire data, and starts the data acquisition timer in continuous conversion mode. After 2 seconds, the acquired data is saved to the FLASH area via the DMA channel.

[0051] The signal is then transmitted via USART to the serial port module and sent to the host computer for digital signal processing.

[0052] Finally, after the host computer completes the processing, the data is transmitted to the DAC pin of the acquisition device, thus completing the program design of the sensor acquisition system.

[0053] In addition, the test excitation source is a 500Hz sine wave with an amplitude of 40mV. After passing through analog circuits such as amplification and filtering, it is sent to the digital circuit section of the acquisition device chip for processing, and finally sent to the host computer for digital signal processing through the serial port of the acquisition device.

[0054] To avoid the influence of mixed spike signals and random signals from the stacked piezoelectric ceramic vibration sensor on experimental analysis, a data processing method based on a Butterworth low-pass filter is used to extract the effective signal, suppress noise, and balance the frequency band amplitude and phase characteristics of the effective signal.

[0055] Based on the desired cutoff frequency and attenuation for the input passband and stopband, the order and cutoff frequency of the Butterworth filter were determined, and the corresponding coefficients were obtained. Simulation results show that the software effectively attenuates the high-frequency signal from the sensor, significantly smooths the data processing, and improves the signal-to-noise ratio of the output signal of the stacked piezoelectric ceramic vibration sensor. Specifically... Figure 7 As shown.

[0056] In addition, sensor data is sent to the host computer via serial port. The host computer processes the data, relating the external non-electrical quantity to the voltage. Considering the small range of change in the excitation source, the host computer uses least-squares linear fitting to approximate the actual static characteristic curve, making the sensor's static characteristics nearly linear. Sensitivity, linearity, hysteresis, and repeatability are analyzed based on the fitted line. Sensitivity and nonlinearity error are calculated, yielding linearity of 1.49% and hysteresis error of 3.6%, verifying the feasibility of each component of the data acquisition system. Specifically... Figure 8 As shown.

[0057] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A piezoelectric conversion and acquisition system for a piezoelectric ceramic vibration sensor, characterized in that, It includes a data acquisition device and a conversion and processing system for the data acquisition device, wherein: The acquisition device and the conversion and processing system are mechanically connected to form a composite component. The conversion and processing system is connected to the host computer and the acquisition device via wired or wireless means, respectively. The acquisition device integrates a circuit unit, which incorporates circuitry for the piezoelectric conversion of the sensor.

2. The piezoelectric conversion and acquisition system of the piezoelectric ceramic vibration sensor according to claim 1, characterized in that, The conversion and processing system includes: the stacked piezoelectric ceramic vibration sensor conversion and processing system mainly consists of a vibration test excitation source module, a piezoelectric ceramic sensing module, a lower-level processing module, and an upper-level processing module.

3. The piezoelectric conversion and acquisition system of the piezoelectric ceramic vibration sensor according to claim 2, characterized in that, The vibration test excitation source module is used to conduct vibration tests and analyses using a suspension mechanical model to obtain effective vibration sources. The piezoelectric ceramic sensing module is used to acquire piezoelectric power signals, collect piezoelectric data, and output piezoelectric signals through circuit units; The lower-level processing module is used to read piezoelectric signals and transmit data via serial port; The host computer processing module is used to organize the data received from the serial port, analyze the data, and obtain the final piezoelectric conversion data.

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