16 results about "Piezoelectric accelerometer" patented technology

The invention relates to the technical field of high-temperature vibration monitoring, and provides a novel compression type structure sensor aiming at the problems of sensitivity attenuation and insufficient thermal stability of a traditional piezoelectric sensor under the working condition of 200-300 DEG C. According to the device, monolithic PZT piezoelectric ceramic is adopted as a sensitive element, and the depolarization temperature is increased to 302 DEG C through a double-doping technology, which is obviously superior to that of similar materials. According to the structural design, the laminated layout of the lower pressing block, the mass block, the insulating sheet, the piezoelectric ceramic and the base is adopted, the insulating sheet is provided with a reserved circular groove and a wiring notch, and efficient lead-out of an electrode wire is achieved. Tests show that the sensor is low in charge sensitivity attenuation in an environment of 300 DEG C and high in inherent frequency. Through single-chip design and material modification, high-sensitivity vibration detection in a high-temperature environment is realized while the preparation process is simplified, and the sensor can be widely applied to the fields of aero-engine monitoring, new energy automobile thermal management and the like.

The invention aims to provide a motor bearing fault diagnosis method under strong noise interference. The method comprises the following steps: A, acquiring an acceleration vibration signal of a motor bearing by using a piezoelectric acceleration sensor; b, taking the minimum envelope spectrum peak factor Ec as a fitness function, optimizing a center frequency omega d and a balance factor alpha in a VME algorithm model by using a WOA algorithm model to obtain a WOA-VME model, and decomposing the collected acceleration vibration signal to obtain an expected modal signal; c, taking the minimum envelope spectrum peak factor Ec as a fitness function, optimizing the size f of a filter in the SMHD algorithm model by using the WOA algorithm model, and processing the expected modal signal by using the WOA-SMHD model to obtain an enhanced expected modal signal; and D, extracting motor bearing fault features from the enhanced expected mode signal, and comparing the motor bearing fault features with the motor bearing fault frequency database to obtain a diagnosis result. According to the invention, motor bearing fault feature extraction of strong background noise can be well realized.

The invention discloses a low-Q-value piezoelectric accelerometer and a preparation method, and the low-Q-value piezoelectric accelerometer comprises a base which is of a hollow structure with the upper end and the lower end being open; the movement assembly comprises a cantilever assembly and a mass block connected to the cantilever assembly; an upper air damping layer is formed in the area where the upper clamping plate layer and the motion assembly coincide in the projection direction; the lower clamping plate layer is connected with the bottom of the base in a bonding mode, a gap exists between the lower clamping plate layer and the mass block, and a lower air damping layer is formed in the overlapped area of the lower clamping plate layer and the mass block in the projection direction. According to the low-Q-value piezoelectric accelerometer provided by the embodiment of the invention, the air damping layers are respectively formed above and below the motion assembly, so that the total damping value of the system is increased, the purpose of reducing the Q value is achieved, the low-Q-value piezoelectric accelerometer is obtained, and the increase of the response bandwidth of the accelerometer is realized.

The invention belongs to the technical field of bearing vibration measurement, and particularly relates to a rolling bearing vibration signal rapid acquisition structure. The device comprises an outer claw mechanism, an inner claw mechanism, a sealing cover, an electromagnetic lifting mechanism and a tested bearing. A flange plate of the outer claw mechanism is connected with a triangular plate of the inner claw mechanism, and a sealing cover is arranged on the flange plate. Guide sliding grooves are formed in the triangular plate and the flange plate, the inner claw fingers and the outer claw fingers can freely slide along the guide sliding grooves, and clamping of rolling bearings of different sizes can be completed; the electromagnetic lifting mechanism penetrates through the flange plate, the triangular plate and a center hole of the sealing cover, and taking, releasing, lifting and falling of the bearing are controlled through electromagnetic attraction. The device can adapt to rolling bearings of different sizes, meanwhile, the piezoelectric acceleration sensors are arranged in the rigid claws, multi-point real-time collection of vibration signals can be achieved, and the device has the advantages of being high in applicability, efficiency and precision.

The invention provides a performance test method for heat pump assembly equipment. The method comprises the following steps: deploying a multi-source sensor at a key part of a compressor to obtain an initial real-time working condition monitoring signal; piezoelectric acceleration sensors are arranged at key nodes of a pipeline of the compressor, and a vibration spectrum monitoring network is constructed to obtain vibration signals; establishing a vibration transmission path model based on a modal analysis theory, and performing transmission trend prediction on the vibration signal to obtain a damping compensation coefficient; performing optimization adjustment on the initial real-time working condition monitoring signal according to a signal source deployment position, and extracting real-time working condition characteristics by combining a wavelet denoising algorithm; inputting the real-time working condition characteristics into an LSTM-based coupling model to predict a transient performance change trend, and obtaining a transient performance characteristic sequence; and generating a dynamic performance change curve and a corresponding performance diagnosis report based on the transient performance feature sequence. Through intelligent heat pump equipment performance evaluation, the equipment operation state is optimized, and the equipment reliability and operation efficiency are improved.

An on-site reciprocity calibration method for a piezoelectric accelerometer, including a vibration test and a reciprocity test. In the vibration test, a sine excitation with a corresponding frequency and amplitude is provided by a vibration exciting device to the piezoelectric accelerometer fixed on a motion plane, and output signals of a drive port and a signal port of the reciprocal piezoelectric accelerometer are collected by a data acquisition device. In the reciprocity test, a sine voltage excitation is provided by a signal generator to the drive port, and then an excitation signal and an output signal of the signal port are collected by the data acquisition device. An amplitude ratio of the two signals is obtained based on signal sine-fitting. Finally, the on-site calibration is enabled according the sensitivity amplitude ratio obtained in the vibration test and the sensitivity amplitude product obtained in the reciprocity test.

1. Name of the product in this design: Piezoelectric accelerometer. 2. Purpose of this design: For use in sensors. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: a 3D model.

This application relates to the field of automatic measurement technology, specifically disclosing a device and method for automatically measuring the time of artificial earthquake excitation. The device utilizes a piezoelectric accelerometer to convert vibration signals into detection electrical signals, processes the detection electrical signals via a data acquisition card to obtain seismic waveform data, and then applies a GPS timestamp to the obtained seismic wave data. The device then uses a long- and short-time window algorithm to analyze the seismic waveform data to capture characteristic changes in the seismic waveform, thereby determining the start time of artificial earthquake excitation. This method avoids the phase shift problem inherent in the excitation response of a moving coil geophone, achieves high-precision automatic measurement of the time of artificial earthquake excitation, and is simple and convenient to use.

A shear mode piezoelectric accelerometer includes a ring-shaped piezoelectric element, a central shaft, a mass block, a first electrode, and a second electrode. The ring-shaped piezoelectric element includes an outer ring wall and an inner ring wall. The central shaft is made of conductive material and is fixed through the inner ring wall of the ring-shaped piezoelectric element. The mass block is made of conductive material and includes a fixed element and a weight element. The fixed element has a fixed hole and is fixed to the outer ring wall of the ring-shaped piezoelectric element by fitting the fixed hole. The weight element is located on the fixed element on the opposite side away from the fixed hole. The first electrode is electrically connected to the central shaft. The second electrode is electrically connected to the mass block.

The invention relates to a pipeline water leakage positioning method, which comprises the following steps of S1, installing piezoelectric accelerometer sensors at valves at two ends of a pipeline, and collecting sound signals in the pipeline; s2, performing MFCC (Mel Frequency Cepstrum Coefficient) feature extraction on the sound signals acquired by the two sensors to obtain a feature sequence corresponding to each sensor, and merging the MFCC feature sequences of the two sensors as the input of a model; s3, the merged feature sequence is input into a pipeline water leakage detection model for analysis, the water leakage detection model comprises an input projection layer, a causal convolution layer and a dynamic state space modeling layer (based on the Mama algorithm), dual-channel dynamic fusion, Mama dynamic state space and physical sensing position coding are adopted, synchronous detection and positioning are output in a multi-task joint mode, and the detection accuracy is improved. Sensitivity is improved, positioning errors are reduced, and real-time performance and multi-working-condition robustness are achieved.

The invention discloses a foundation pile 3D imaging method fusing double traveling wave excitation and diffraction scanning migration technologies and application of the foundation pile 3D imaging method. A piezoelectric accelerometer is installed in the center of the top of a foundation pile; a plurality of three-axis accelerometers are arranged on the pile top plane and the side wall of the foundation pile correspondingly, and multi-channel dual-mode time domain signals are obtained; performing wave field separation and noise reduction processing on the signal; the method comprises the following steps: establishing a foundation pile column coordinate system velocity model by utilizing a diffraction scanning theory, constructing a three-dimensional velocity field, preliminarily extracting first arrival wave travel time of each sensor, inverting initial wave velocity distribution through a least square method, and discretizing a foundation pile three-dimensional space into a high-density grid; each grid point is assumed as a potential defect diffraction source, and theoretical travel time and amplitude response of a signal reaching each sensor are calculated through a finite difference method; performing point-by-point scanning superposition on original wave field data, correcting phase offset by combining a dynamic wave velocity model, and performing weighted superposition on energy coherence of each diffraction point to generate a 3D image; and identifying the foundation pile defect based on the 3D image.

This invention discloses an embedded piezoelectric accelerometer structure, belonging to the technical field of piezoelectric accelerometers. The embedded piezoelectric accelerometer structure includes a base with a groove. Two first piezoelectric elements are disposed within the groove, and an elastic mass block is positioned between the two first piezoelectric elements. The elastic mass block causes the two first piezoelectric elements to respectively adhere to two sides of the groove. The weight of the first piezoelectric elements and the elastic mass block is supported by the two sides of the groove on the base. Without the central column of the traditional shear structure, the limitation of the central column structure on miniaturization is overcome, increasing the potential for miniaturization of the sensor structure. Simultaneously, the support on both sides of the groove provides greater stiffness than the support of a single central column, allowing the sensor to achieve a wider frequency response range and smaller measurement errors.

The invention discloses laminated co-fired piezoelectric ceramic with a hole in the center and application of the laminated co-fired piezoelectric ceramic in a piezoelectric acceleration sensor. The piezoelectric ceramic is prepared from at least two kinds of piezoelectric ceramic powder with different phase transition temperatures. The method comprises the following steps: preparing ceramic slurry from piezoelectric ceramic powder; preparing the ceramic slurry into a thin film through a tape casting process to obtain a film belt; cutting the film belt, printing an upper electrode structure, then stacking and hot-pressing the film belt by adopting an interdigital electrode mode, cutting the hot-pressed film belt into single independent laminated ceramic, and forming a circular through hole in the center of the single laminated ceramic; carrying out high-temperature sintering on the single laminated ceramic, and then polishing the end surface of the laminated ceramic; and finally, arranging an end electrode on the end surface of the laminated ceramic and carrying out polarization treatment to obtain the perforated laminated co-fired piezoelectric ceramic. The piezoelectric ceramic is designed for the piezoelectric acceleration sensor, and can meet the comprehensive performance requirements of the piezoelectric acceleration sensor on high sensitivity, wide band and high reliability.

The invention provides a sensing device for monitoring the pile sinking effect of an offshore pile foundation, and relates to the field of ocean engineering and geotechnical engineering monitoring, the sensing device comprises a main floating platform, a plurality of vertical multidirectional diversion positioning columns are fixedly arranged at the bottom of the main floating platform, and the multidirectional diversion positioning columns are vertically arranged; the multidirectional flow guide positioning columns play a role in preliminary fixing and positioning, and a pile driver connector base is fixedly arranged at the top of the main floating platform. Precise positioning and environment adaptation are achieved through the multi-direction flow guide positioning column, a high-frequency piezoelectric accelerometer and a waterproof strain gauge are arranged in the integrated sensing pile body, shear thickening fluid buffering protection is matched, it is ensured that data are continuous and reliable under the extreme working condition, meanwhile, the soil-water coupling monitoring unit captures pile periphery soil stress and pore water pressure changes in real time, and the monitoring precision is improved. And the pile sinking effect is revealed.

The application belongs to the technical field of electric digital data processing, and discloses a piezoelectric accelerometer signal conditioning method and circuit for low-frequency vibration measurement.The method comprises the following steps: selecting multiple IC piezoelectric accelerometers to be reversely docked and installed, forming two branches, and being used in pairs so that the sensed alternating acceleration signals are opposite to each other; using matched transistors to form a multi-channel constant current source for power supply; using multiple instrument amplifier chips to form a differential amplification circuit, adopting a direct current coupling connection form, introducing the signals of multiple IC piezoelectric accelerometers into the differential amplification circuit, doubling the sensitivity of the alternating acceleration signals while offsetting the direct current bias voltage; the similar direct current bias voltages are subtracted to be zero; and using the high common mode rejection ratio characteristic of the instrument amplifier chip, the common mode noise is further suppressed through two-stage differential amplification.The application further suppresses the common mode noise through two-stage differential amplification, and improves the signal-to-noise ratio of a low-frequency broadband test signal.

The application provides a kind of three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, comprising: first shell, second shell, hanger, filler, piezoelectric accelerometer and electrode device;Second shell is fixed in first shell by hanger, and the filler is filled between the second shell and the first shell;Piezoelectric accelerometer includes communication block, three polarized piezoelectric fibers, balancing piece and acoustic signal receiving ball, communication block is supported in the second shell by support column, three polarized piezoelectric fibers are mutually orthogonal, and one end is fixed on communication block, the other end is connected with acoustic signal receiving ball through second shell along first direction, second direction and third direction respectively, and the balancing piece is fixed on the communication block;The electrode device is wrapped on the surface of the polarized piezoelectric fiber.The sensor structure of the application is small, can detect low frequency signal, and has high sensitivity to acoustic signal, and is suitable for industrial production.