403 results about "Low frequency vibration" patented technology

The invention relates to a low-frequency vibration isolator with a wide quasi-zero stiffness interval. The low-frequency vibration isolator comprises a bearing platform, a base, a first negative stiffness assembly, a second negative stiffness assembly and a linear vibration isolation assembly. The bearing platform and the base are arranged in parallel and are both provided with bolt holes and limiting holes; a linear vibration isolation assembly is installed between the bearing platform and the base. The first negative stiffness assemblies are symmetrically distributed with the center point connecting line of the bearing platform and the base as the symmetry axis. The top of the first negative stiffness assembly is connected with the bearing platform, and the bottom of the first negative stiffness assembly is connected with the base. The two ends of the second negative stiffness assembly are connected with the two first negative stiffness assemblies correspondingly. The low-frequency vibration isolator has the characteristics of high static rigidity and low dynamic rigidity, the contradiction between the bearing capacity and the vibration isolation performance of a linear vibration isolation system is effectively solved, and the effective low-frequency vibration isolation effect on a vibration-isolated object is achieved while the bearing capacity of the vibration isolator is guaranteed.

The invention relates to a robot multi-frequency vibration composite suppression method and system based on inertia disturbance analysis. The method comprises the steps of obtaining dynamic operation data in the operation process of a robot; the operation data are input into an inertia disturbance analysis module, and a low-frequency vibration source caused by a mechanical structure and a high-frequency vibration source caused by a driving system can be accurately recognized; a disturbance frequency distribution diagram is generated, according to the distribution diagram, a self-adaptive filtering algorithm is adopted to suppress a high-frequency vibration source, a compensation algorithm based on model prediction control is adopted to suppress a low-frequency vibration source, the two strategies are cooperatively processed to generate a comprehensive control instruction, the advantages of the two algorithms are fully played, and effective composite suppression of multi-frequency vibration is achieved.

The invention relates to a multi-machine cooperative dynamic balance driving method, system and device for a spiral lifting machine, and the method comprises the steps: carrying out the compensation of the time lag of an actuator through employing a non-linear state observation and time lag compensation combined method, and obtaining a feedforward control quantity; performing Lyapunov stability feedback processing on the vibration acceleration signal to obtain a vibration suppression control quantity; designing a multi-section S-shaped speed curve, and calculating a closed-loop feedback control quantity by adopting PID (Proportion Integration Differentiation) combined with a robust control algorithm; and according to the feedforward control quantity, the vibration suppression control quantity and the closed-loop feedback control quantity, multi-machine cooperative dynamic balance driving of the spiral lifting machine is carried out. According to the invention, a non-linear state observation and time delay compensation technology is adopted, so that the synchronization error is reduced to a millisecond level; the low-frequency vibration amplitude is reduced through dynamic feedback control designed based on the Lyapunov theory; the hydraulic impact is obviously reduced by adopting a multi-section S-shaped speed curve; external disturbance is observed in real time through Kalman filtering, feed-forward compensation is carried out, and the robustness of the system is greatly enhanced.

The invention discloses a spiral air duct predictive operation and maintenance method and system based on digital twinning, and relates to the technical field of air duct system state monitoring and operation and maintenance, and the method comprises the following steps: deploying a high-frequency acoustic emission AE sensor and a low-frequency vibration acceleration sensor at key nodes of a spiral air duct, and taking a fan start-stop signal and operation power as working condition labels; a high-frequency acquisition mode is automatically triggered, noise reduction processing is carried out, and a multi-mode acoustic vibration original signal data set which is provided with a time sequence and a working condition label and is subjected to preliminary noise reduction is output; the high-frequency acoustic emission AE sensor and the low-frequency vibration acceleration sensor are arranged in the spiral duct, the health state of the thin-wall structure is monitored in real time through the high-frequency acoustic emission technology, weak early-stage fault signals in the duct can be accurately captured and early warning can be given out in the fault germination stage of fretting wear, sealant aging and the like of the spiral duct, and the fault early-warning effect is achieved. Real-time monitoring, early warning and accurate operation and maintenance of the spiral air pipe are achieved.

The invention belongs to the technical field of low-frequency vibration control, and provides a low-frequency tuned mass damping device for reversely stretching a compression spring in order to solve the problem that a traditional tuned mass damper is limited in use of a vertical space due to too large net deformation of the spring under the low-frequency condition. According to the device, large compression deformation and reverse tensile deformation of the spring are fully realized in a limited vertical space in a manner of performing super-compression-reverse tensile treatment on the compression spring, relatively low rigidity required by a vibration system is achieved, low-frequency tuning can be realized in the limited vertical space of a bridge girder, and the rigidity of the vibration system is improved. The frequency application range of the tuned mass device is greatly expanded; and meanwhile, the problems that the stability problem is caused when a traditional compression spring mass body is arranged on the spring and the damping is too high and unstable due to the fact that a guide component is added are solved. The device is simple in structure, low in damping, low in space requirement and good in stability, and can be applied to vertical, lateral and torsional multi-type low-frequency vibration control of various engineering structures.

The invention provides a self-powered vibration sensor based on multi-mode energy capture, and the sensor comprises a multi-mode vibration energy capture unit which comprises a piezoelectric ceramic piece and an electromagnetic induction coil-permanent magnet assembly, and the piezoelectric ceramic piece and the electromagnetic induction coil-permanent magnet assembly are installed on the surface of equipment in parallel, the piezoelectric ceramic is used for capturing 100-200Hz high-frequency vibration energy; the electromagnetic induction coil-permanent magnet assembly is used for capturing low-frequency vibration energy of 5-50 Hz; the energy acquisition power supply management circuit comprises a double-path rectification filter circuit, a first bidirectional DC-DC converter and a super capacitor / lithium battery hybrid energy storage unit; the first bidirectional DC-DC converter is connected with the two-way rectification filter circuit and the super capacitor / lithium battery hybrid energy storage unit at the same time, and is used for controlling charging and discharging of the super capacitor / lithium battery hybrid energy storage unit based on a preset dynamic impedance matching network and an energy priority scheduling strategy.

The invention relates to the field of buried facility monitoring, and discloses a piezoelectric cantilever vibration sensing and super capacitor self-powered energy closed-loop operation method and system, and the method comprises the steps: building a star array composed of a master pile and a slave pile, and configuring a TDMA time slot and an uplink message length; the slave pile collects a vibration signal through a piezoelectric cantilever, the vibration signal is rectified by a piezoelectric rectification energy taking module and then charges a super capacitor, and the voltage state of the two ends of the super capacitor is obtained; when the voltage state reaches a preset upper threshold, the boosting module supplies power to the processing circuit and the transmitting circuit of the slave pile, and the processing circuit generates a four-byte feature code; the slave piles send four-byte feature codes in a magnetic induction link according to TDMA time slots, the master pile receives and aggregates the four-byte feature codes sent by the multiple slave piles, completes positioning and fusion according to the arrival time difference, and returns the four-byte feature codes to the platform through LoRa and 4G, and the platform completes storage and output according to the four-byte feature codes and a positioning result. According to the invention, end-side cloud connection and replicable deployment can be realized, and low-frequency vibration acquisition and buried communication are adapted.

The utility model relates to the technical field of vehicle signal devices, and provides a vehicle-mounted loudspeaker mounting structure and a vehicle. The vehicle-mounted loudspeaker mounting structure is used for mounting a vehicle-mounted loudspeaker on a vehicle body and comprises a mounting base body provided with the vehicle-mounted loudspeaker, a connecting assembly and a damping assembly. The connecting assembly comprises a connecting piece for connecting the mounting base body and a vehicle body; the damping assembly comprises a damping bush arranged on the connecting piece in a sleeving mode and a supporting bush located between the damping bush and the connecting piece. The vehicle-mounted loudspeaker mounting structure not only has better structural stability and is beneficial to ensuring the mounting reliability of the vehicle-mounted loudspeaker, but also can absorb high and low frequency vibration generated when the vehicle-mounted loudspeaker works and reduce adverse effects caused by vibration of the vehicle-mounted loudspeaker, thereby being beneficial to improving the driving comfort and the driving safety coefficient.

The invention relates to the technical field of shock absorption, and discloses a frequency self-adaptive shock absorber which comprises a cylinder body, a piston assembly and a frequency response structure. The piston assembly comprises a piston body and a piston rod. The frequency response structure is integrated in the piston rod and comprises a communicating channel, a mounting hole, an adjusting rod, an elastic piece and a plunger sleeve, the plunger sleeve is arranged in the communicating channel, a conical convex part is arranged at one end of the adjusting rod, an overflowing gap is formed between the peripheral face of the conical convex part and a port of the plunger sleeve, and the elastic piece is connected with the end, deviating from the plunger sleeve, of the adjusting rod. The frequency response structure is integrated in the piston rod, the elastic piece made of the nonlinear elastic material is used for sensing the oil pressure frequency change, the adjusting rod is driven to move in combination with the oil pressure, the damping force can be reduced at high frequency and increased at low frequency, and self-adaptive adjustment of the damping force of the shock absorber under high and low frequency vibration road conditions is achieved. According to the design, a complex frequency control valve does not need to be additionally arranged, and the cost, the structural complexity and the overall size of the damper can be remarkably reduced.

The invention belongs to the technical field of vibration isolation, and particularly relates to a quasi-zero stiffness metamaterial sandwich structure, a vibration isolation device and a manufacturing method. The quasi-zero stiffness metamaterial sandwich structure is formed by periodically arranging unit cells in the horizontal direction, and each unit cell comprises an upper panel, a lower panel, a QZS resonator core body and a vertical supporting column; the QZS resonator core comprises a central mass block, QZS resonator units are arranged on the upper portion and the lower portion of the central mass block in a mirroring mode, each QZS resonator unit is composed of two quasi-zero-stiffness unit cells which are arranged in a crossed mode, and each quasi-zero-stiffness unit cell is composed of a negative-stiffness component comprising a horizontal curved beam and a positive-stiffness component comprising an oblique straight beam. According to the sandwich structure, the quasi-zero-stiffness resonator of a novel structure serves as a core body, wider application in the ultra-low frequency vibration reduction field can be achieved, the band gap is adjustable, and the problems that a traditional metal base material structure is high in band gap frequency and limited in application field can be solved.

The invention discloses a cold atom interference type low-frequency vibration measurement device and a measurement method, and solves the problems that the existing cold atom interference gravimeter measurement equipment is limited by the performance of a vibration sensor, the compensation precision is insufficient, timing calibration is needed, and the measurement precision is low. And measurement errors generated by gravity and ultralow-frequency vibration cannot be effectively separated from a measurement result of the cold atom interference gravimeter, namely, decoupling of two measurement parameters is realized, and cold atom interference measurement of low-frequency vibration is realized. The measuring device comprises a Raman laser output system, a vacuum cavity, a sensitive axis converter and a vibration detection reflecting mirror, the Raman laser output system outputs two pieces of Raman laser which have the same polarization state and are both circular polarization states; the low-frequency vibration is transmitted to the liquid crystal phase modulator through the vacuum cavity for polarization state conversion, and then is reflected to the liquid crystal phase modulator or the vibration detection reflector through the polarization splitting prism, so that the interference type low-frequency vibration of the cold atoms is measured, and decoupling of the two is realized.

Anti-vibration units are provided for vibration suppression in multiple directions. The anti-vibration units may have an X-shaped structure as part of its support structure. The anti-vibration units can work for ultra-low frequency vibration isolation in three directions in a passive manner. The anti-vibration units can achieve a flexible nonlinear stiffness, which contains zero or quasi-zero stiffness, negative stiffness and positive stiffness. A smooth multi-equilibria state is also achievable. Compared with traditional spring-mass-damper (SMD) and typical QZS systems, the provided anti-vibration units can have an enhanced QZS range of larger stroke with guaranteed loading capacity, and can also achieve a lower resonant frequency with a lower resonant peak. At least some embodiments of the anti-vibration units may include a new and innovative arrangement of components that enables a more compact design than typical anti-vibration systems.

The invention belongs to the technical field of low-frequency vibration control, and discloses a low-frequency low-damping tuned mass damping device which is mainly composed of a rigid support, a first sling, a rotating arm, a cable hole, a first arc guide groove, a second arc guide groove, a lock pin, a second sling, a first mass block, a spring, a second mass block and a damping element. The flexible suspension rotation replaces the bearing or ball screw support, so that the damping is obviously reduced; the long rotating arm is combined with the equivalent large-diameter arc guide groove, so that the low-frequency low-damping tuned mass damping device can achieve large vertical displacement at a small rotating angle, and damping is reduced. The low-frequency low-damping tuned mass damping device innovatively adopts double-mass-block configuration, so that static force borne by a spring is generated by mass difference, and static deformation of the spring is remarkably shortened. According to the method, low-frequency operation can be achieved under the condition that the space is limited, the low-damping characteristic is kept, it is guaranteed that the requirement for the optimal damping ratio is met, and therefore a new technical approach is provided for control over low-frequency vortex vibration of a large-span bridge.

The invention discloses an electromagnetic vibration table for an uncooled infrared machine core assembly adopting multiple sensors, and relates to the technical field of vibration tables. By arranging four groups of vibration testing mechanisms of low frequency, intermediate frequency, high frequency and ultrahigh frequency, vibration waves of different frequencies can be synchronously or alternately generated, complex operation conditions of the uncooled infrared movement in real environments such as transportation jolting, mechanical shock and high-frequency vibration can be simulated, and vibration testing of different vibration frequencies can be performed on a plurality of uncooled infrared movement assemblies at the same time. Wherein the low-frequency vibration testing mechanism and the intermediate-frequency vibration testing mechanism can simulate low-frequency vibration in a transportation process, the high-frequency vibration testing mechanism can simulate high-frequency noise interference in operation of the uncooled infrared movement, and the ultrahigh-frequency vibration testing mechanism can simulate an instantaneous impact working condition of the uncooled infrared movement in an extreme environment. Therefore, each uncooled infrared movement to be tested can undergo vibration tests in various modes, full-band coverage tests are realized, and the accuracy and credibility of test results are greatly improved.

The invention discloses a biological soft tissue crack quantitative detection method based on elastic wave dispersion characteristics, and the implementation process comprises the following steps: firstly, preparing a soft tissue sample, and applying initial stress to obtain a soft tissue sample strain geometric model and a material stress initial value; then applying low-frequency vibration to the surface of the soft tissue sample, tracking and positioning the vibration, establishing a constitutive relation model of the soft tissue and an increment form, and establishing an inversion model, thereby inverting detailed information such as crack length, angle, fracture mechanical parameters and the like from wave velocity change, and on the basis, determining the fracture velocity of the soft tissue sample. Finite element simulation software is used for conducting crack area local wave field simulation and wave scattering and fracture mechanical simulation on the platform, the accuracy and stability of an inversion result are verified, then after data marked correctly and wrongly are obtained, a reinforcement learning model is input to optimize the inversion result, and finally a crack form data set is obtained; and estimating whether the risk that the crack continues to expand exists or not.

The invention discloses a fan variable pitch bearing intelligent monitoring method and system based on multi-parameter fusion, and the method comprises the steps: respectively calculating angles based on a three-axis acceleration and a three-axis angular velocity, and obtaining a final angle through complementary filtering fusion; carrying out ensemble empirical mode decomposition on the three-axis vibration signals, respectively extracting low-frequency vibration characteristics, high-frequency vibration characteristics and angle variation based on a plurality of signal components, carrying out fusion decision on the low-frequency vibration characteristics, the high-frequency vibration characteristics and the angle variation by adopting a D-S evidence theory to obtain a total confidence coefficient, and judging a fault in combination with a preset fault threshold to obtain a first fault diagnosis result; the low-frequency vibration characteristics, the high-frequency vibration characteristics and the angle variation are input into a deep residual network diagnosis model for processing, and a second fault diagnosis result is obtained; and comparing the first fault diagnosis result with the second fault diagnosis result, outputting a final diagnosis result if the first fault diagnosis result is consistent with the second fault diagnosis result, and performing diagnosis again if the second fault diagnosis result is inconsistent. The limitation of a single sensor frequency band is broken through, a D-S evidence theory is innovatively adopted to carry out multi-source evidence fusion decision, and the fault recognition rate is improved.

The invention relates to the technical field of energy collection systems, and discloses a combined low-frequency vibration energy collector which comprises a lower-layer structure and an upper-layer structure which are combined to form an upper-layer and lower-layer coupled structure. The lower layer structure is an arc-shaped flexible beam, and the arc-shaped flexible beam is used for collecting piezoelectric energy generated by bending deformation; the upper layer structure is a T-shaped cantilever beam, the T-shaped cantilever beam is used for responding to bending modes in different directions and realizing multi-point energy collection, and the energy collection efficiency is improved by introducing mass load to regulate and control structural dynamic behaviors; the first end of the arc-shaped flexible beam is used for being fixed to the edge of a base to conduct energy conversion, the second end of the arc-shaped flexible beam supports the upper layer structure through the first mass block and is combined to form an integrally-connected composite vibration system used for transmitting inertial response, and the first mass block is used for adjusting the inherent frequency to be matched with a low-frequency vibration source.

The invention relates to the technical field of vibration control, and particularly provides an ultralow-frequency passive self-adaptive tuning vibration absorber based on a string-mass system, which comprises a mechanical sensing assembly, a mechanical driving assembly, a mechanical transmission assembly and a tuning vibration absorption assembly which are arranged on a target structure, the mechanical sensing assembly and the mechanical driving assembly are correspondingly arranged, and the mechanical sensing assembly is used for sensing vibration of a target structure and can generate relative movement; the mechanical driving assembly is connected with the mechanical transmission assembly, and the mechanical driving assembly drives the mechanical transmission assembly to work based on relative motion generated by the mechanical sensing assembly; the mechanical transmission assembly is connected with the tuning vibration absorption assembly. The vibration absorber is wide in application range, compared with an existing self-adaptive tuning vibration absorber, the vibration absorber has the advantages that external power supply driving is not needed, the structure is simple, ultralow-frequency vibration control can be achieved, and effective control over broadband even multi-order modal vibration is achieved through a pure mechanical structure.

The invention discloses an insect body echo self-adaptive filtering method based on micro-motion phase self-correlation matching, belongs to the technical field of radars, and is used for solving the problems that an existing filtering mode of the main Doppler frequency of an insect target has certain limitation, full-scene adaptation is difficult to realize by a fixed window length, and the filtering efficiency is low. And low-frequency filtering causes that the insect target in low-frequency vibration flight cannot be effectively extracted and identified. The method comprises the following steps: carrying out instantaneous Doppler frequency model modeling processing on an original insect echo signal to obtain a target instantaneous Doppler frequency model; performing smoothing processing based on different sliding window lengths on the target echo phase to obtain a micro-motion phase after the main Doppler component is filtered; carrying out self-correlation function calculation under a related self-adaptive window length on the micro-motion phase after the main Doppler component is filtered out; determining an optimal filtering window length corresponding to the current insect phase signal; and performing slow-time signal echo compensation processing on the current insect phase signal to obtain a micro-motion signal of the current insect.

The invention discloses an electric toothbrush and a control method and device thereof, and relates to the technical field of electric toothbrushes, the electric toothbrush comprises a brush head, in the control method of the electric toothbrush, when the electric toothbrush is in a power-on state, the contact pressure between the brush head and the tooth surface and the position information of the brush head are obtained; the vibration intensity of the brush head is adjusted according to the contact pressure; the current cleaning area is determined according to the position information, the brush head is controlled to move according to the corresponding movement mode based on the current cleaning area so that the movement track of the brush head can be matched with the current cleaning area, and the movement mode comprises any one or more combinations of a low-frequency vibration mode, a high-frequency vibration mode, a rotation mode and a reciprocating swing mode. The cleaning effect of the electric toothbrush is improved, and therefore the user experience feeling is improved.

The invention relates to the technical field of electronics, in particular to an open type earphone which comprises a sound production unit, a vibration unit, a signal processing module and a shell, the signal processing module and the sound production unit are arranged in the shell, the vibration unit is arranged on the shell, and the signal processing module is electrically connected with the vibration unit and the sound production unit; the signal processing module is configured to output a low-frequency vibration signal corresponding to an audio signal to be played; the vibration unit is configured to receive a low-frequency vibration signal; the sound production unit is configured to receive an audio signal to be played; the open type earphone has a wearing state, and in the wearing state, the vibration unit can abut against the ear. The invention mainly aims to provide an open type earphone, and aims to ensure that low-frequency experience is remarkably improved through touch compensation while the open type earphone keeps comfort.

The application provides an electromagnetic inertial actuator, permanent magnets, inner yoke iron and outer yoke iron are fixedly connected by using non-magnetic retainer, so that only ampere force exists in the magnetic circuit system, and good output linearity of the actuator is ensured. On this basis, disc-shaped spring plates with quasi-zero stiffness characteristics are arranged, the inherent frequency of the system is reduced, and low-frequency output performance is ensured. The permanent magnets, the inner yoke iron, the outer yoke iron, the end cover and the heat dissipation device are integrally designed, a large inertial actuator mover mass is formed, the effective mass of the actuator, i.e. the ratio of the mass of the movable part to the total mass, is maximized. In this way, the low-frequency output and the output value per unit mass can be improved, the total volume and mass of the inertial actuator are effectively reduced, and the installation space is saved. Meanwhile, increasing the mass of the mover can effectively reduce the low-frequency vibration displacement of the inertial actuator, and the quasi-zero stiffness characteristics can be further ensured to be realized and stable.

The invention provides a low-frequency tuned mass damper which comprises a mass damping unit, a frequency modulation supporting unit and a fixed force transmission unit, an included angle is formed between the mass damping unit and the vibration direction of a main structure, the frequency modulation supporting unit is arranged at the bottom of the mass damping unit, and the fixed force transmission unit is connected with the main structure. The vibration frequency of the mass damping unit is adjusted by changing the recovery acceleration; the mass damping unit comprises a mass transmission part, a rotating part, an eddy current damping part and a swing part which are sequentially connected from the included angle of the mass damping unit to the bevel edge direction, and the swing part is rotationally connected to the fixed force transmission unit. The mass transmission part comprises a mass block and a rotation transmission part providing rotation acting force for the mass block, and the mass block makes contact with the rotation transmission part and is fixedly connected with the rotating piece. The invention has the advantages of solving the problem of low-frequency vibration, reducing the structural size, reducing the installation difficulty and the like.

The present application belongs to the technical field of low-frequency vibration control, and aims at the problem that the traditional tuned mass damper is limited in vertical space use due to the excessive spring net deformation under low-frequency conditions, and provides a low-frequency tuned mass damper device which reversely stretches the compression spring. The device fully realizes the compression large deformation and reverse stretching deformation of the spring in the limited vertical space through the way of over-compression and reverse stretching of the compression spring, so as to achieve the required low stiffness of the vibration system. The low-frequency tuning can be realized in the limited vertical space of the bridge girder, and the frequency application range of the tuned mass device is greatly expanded. At the same time, the stability problem of the traditional compression spring mass body placed on the spring and the problem of excessive and unstable damping caused by the increase of the guide component are avoided. The device has simple structure, low damping, low space requirement and good stability, and can be applied to vertical, lateral and torsional multi-type low-frequency vibration control of various engineering structures.

The invention provides a resonance unit, a damping device and an applicable reactor thereof. The resonance unit comprises: a substrate having a first surface and a second surface opposite to each other, and an outer peripheral surface located between the first surface and the second surface; the resonance block is located on the first surface and the second surface, and the resonance block comprises a rigid material; the connecting unit comprises a connecting frame and a plurality of connecting columns, the connecting frame surrounds the base plate, each connecting column comprises a first end face and a second end face which are opposite to each other, the first end face is connected with the peripheral face of the base plate, the second end face is connected with the inner wall of the connecting frame, and the connecting unit comprises a flexible material. According to the resonance unit, the damping device and the applicable reactor, low-frequency vibration generated in the operation process of equipment in the reactor can be effectively inhibited, so that the service life of the equipment is prolonged, and the operation safety is improved.

The invention provides a deep-buried cavern blasting vibration safety assessment method considering unloading vibration frequency influence, which comprises the following steps: performing low-frequency characteristic analysis on an actually measured vibration signal, emphatically considering low-frequency vibration response induced by crustal stress transient unloading, establishing a low-frequency vibration safety assessment system, and evaluating the blasting vibration safety of a deep-buried cavern. Therefore, more accurate and reliable evaluation of the blasting vibration safety of the deep-buried cavern is realized. The method provides scientific theoretical support and operable technical basis for safe construction of underground engineering under the high ground stress condition. The method is suitable for underground workshops of large hydropower stations with the burial depth exceeding 500 m, long and large tunnel engineering, deep mineral resource exploitation and the like.

The application discloses a production line fault checking method based on a regional attention learning mechanism, relates to the technical field of production line fault checking, and synchronously collects low-frequency vibration, high-frequency acoustic emission and temperature time sequence signals, covers multidimensional fault characteristics such as mechanical wear, shaft misalignment and thermal effect abnormality, and solves the problem that traditional single signal detection is not complete. According to different signal characteristics, key abnormal characteristics are focused, redundant noise is filtered, and the effectiveness of the characteristics is improved. A collaborative degradation factor model is constructed based on health history data, the weight coefficient is dynamically adjusted through maintenance post-down rate feedback, the device working condition change is adapted, and the poor adaptability of the static model is avoided. The maintenance effect (collaborative degradation factor down rate) is quantitatively evaluated, accurate maintenance is guided, invalid maintenance is reduced, and the production line operation and maintenance efficiency is improved.

This utility model discloses a displacement-amplified composite friction damper. The upper connecting plate has three sets of equidistant axial connecting ends at its bottom; three sets of equidistant extension plates are located above the core plate, and friction shear components are installed on both sides of the core plate; a lever plate is installed between the axial connecting ends and the extension plates; connecting shafts pass through the axial connecting ends and the extension plates respectively to reinforce the installation of the lever plate; large side plates are fixed at both ends of the lower connecting plate, and the large side plates are tightly fitted to the core plate through the friction shear components. After being amplified by the lever plate, the relative displacement between the upper and lower connecting plates will be greater than the displacement generated by the original building structure. In the small displacement stage: the vulcanized rubber layer absorbs energy through elastic deformation, and the friction plates and steel plates remain relatively stationary, achieving low-frequency vibration isolation. In the large displacement stage: when the vulcanized rubber layer reaches its deformation limit, the steel plate and friction plates begin to slide and rub, significantly improving energy consumption efficiency and adapting to extreme conditions such as earthquakes. The overall structure is simple and easy to install.

The invention discloses a piezoelectric MEMS loudspeaker based on a folding ring between movable and fixed parts and application thereof, and belongs to the technical field of loudspeakers, the piezoelectric MEMS loudspeaker comprises a piezoelectric actuating assembly, a fixed assembly and a folding ring; the piezoelectric actuating assembly comprises a piezoelectric actuating composite layer, the piezoelectric actuating composite layer at least comprises a piezoelectric material layer, and the piezoelectric actuating composite layer generates mechanical displacement by applying voltage to drive the piezoelectric actuating assembly to vibrate so as to generate sound pressure; the fixing component can be a single structural component or a component with a plurality of structural components; the fixing assembly can be used for fixedly supporting the fixed supporting part of the piezoelectric actuating assembly, so that the non-fixed supporting part of the piezoelectric actuating assembly can freely move or vibrate; according to the invention, through the innovative design based on the folding ring between the moving part and the fixed part, the low-frequency vibration displacement of the vibrating diaphragm is remarkably improved, the problem that the low-frequency sound pressure of a traditional piezoelectric MEMS loudspeaker is insufficient is effectively solved, and the vibrating diaphragm can push air with a larger volume in a low-frequency band, so that a fuller low-frequency sound effect is obtained.

The present application belongs to the technical field of low-frequency vibration control, aiming at the problems of high damping ratio, instability, low vibration control efficiency and unsuitable for large-scale engineering of existing inertial damper, a low-damping tuned inertial damper device is provided, which provides the possibility for the whole system to realize the required optimal damping ratio, and further efficiently controls low-frequency resonance. Unlike traditional rigid support and transmission mode, the device adopts economical, reliable and convenient flexible suspension support and transmission mode to realize low frequency and stable low damping of the system. The flexible support part and the rigid inertial device are in contact transmission around, which eliminates the high damping caused by high energy consumption due to instability caused by friction and collision in traditional inertial tuned mass damper, so as to ensure that the large inertial system realizes stable low damping ratio, meets the needs of realizing optimal control effect, and is directly applied to large engineering structure resonance control.