574 results about "Vibration velocity" patented technology

The invention provides a temporal-spatial joint filtering high-resolution DOA (Direction of Arrival) estimation method based on a compressed sensing technology. The method comprises the following steps: (1) acoustic pressure vibration velocity joint temporal filtering, to be specific, carrying out rotating combination on the data of an acoustic vector sensor, and utilizing differences in the corresponding properties of a signal and noise to carry out denoising processing; (2) matrix spatial filtering, to be specific, carrying out spatial filtering on the temporally filtered data by a matrix spatial filter of which the maximum value of the mean square error of attenuation in a stop-band and a passband is minimum; and (3) compressed sensing DOA estimation by the array of the acoustic vector sensor, to be specific, receiving data and a manually formed spatial over-complete redundance dictionary via an input array preprocessed by temporal filtering, and seeking the sparse representation of the signal to carry out vector spatial spectrum estimation. The method has great spectral resolution capability in the high-resolution DOA estimation problem of a high-speed motion target under single snapshot conditions and is insensitive to the wideband and narrowband properties and coherent properties of the signal.

The invention relates to a vibration absorbing method for cut presplitting blasting, which comprises the steps that blasting tunneling is performed on a face of a subway tunnel; a gadder is used to drill blastholes including presplitting blastholes, cutholes, assistance holes, periphery holes and bottom plate holes; the presplitting blastholes are a group of transversely arranged blastholes that are located 500mm-600mm above the cutholes; the presplitting blastholes adopt mixed connected kerf cartridges for explosive loading; the cutholes, the assistance holes, the periphery holes and the bottom plate holes adopt common emulsion explosive loading, and adopt millisecond nonel detonators; and the presplitting blastholes, the cutholes, the assistance holes, the periphery holes and the bottom plate holes are initiated in sequence. The vibration absorbing method has the benefits that as a presplitting surface and a presplitting crushed zone are formed above the cutholes, the vibration is reduced and absorbed in transmission paths, the vibration velocity caused by the cut blasting is reduced obviously, and blasting vibration can be controlled effectively. Compared with the traditional smooth blasting, the maximum blasting vibration velocity can be reduced by 30%, and effects on protected heritages along a line are reduced.

The invention provides statistically optimal near-field acoustical holography used for visual recognition of air-conditioner noise sources and an operation method thereof. The operation method comprises the followings: determining the positions, frequency characteristics and distribution ranges of the noise sources, and distance between microphones on microphone arrays, number, sample rates and number of sampling points of microphones; calibrating arrayed microphones; collecting data; recording sound pressure data; processing the sound pressure data; reading the processed data and finally entering noise source recognition procedures. By the invention, complex sound pressure on reconstructive surfaces and vibration velocity of surface particles can be calculated directly via linear superposition of the complex sound pressure on a holographic plane in a spatial domain, thus essentially overcoming window effects and wraparound errors existing in near-field acoustical holography and avoiding the problems brought about by the demand of a large number of microphones by near-field acoustical holography, such as low reconstruction efficiency of sound fields and costly cost of measuring systems, etc. The invention is characterized by small number of demanded microphones, low measuring cost and high reconstruction efficiency of the sound fields.

The invention provides a passive positioning method of a single-vector hydrophone. The passive positioning method includes: (1) performing short-time Fourier transformation on acoustic pressure signals to obtain time frequency distribution of noise signals; (2) extracting time history of strong line spectrum signals, evaluating the recent passing time of a target according to the time history of a line spectrum frequency, and evaluating the moving speed of the target according to Doppler frequency offset of the line spectrum; (3) finding the direction of the target corresponding to the line spectrum according to the acoustic pressure signals and horizontal vibration velocity signals received by the single-vector hydrophone, and obtaining the direction time history of the target during the point measuring process; and (4) evaluating motion tracks of the target according to the direction time history and motion speed of the target. The passive positioning method of the single-vector hydrophone has the advantages of being capable of positioning the target only by continuously measuring the acoustic pressure and the horizontal vibration speed information without knowing the hydrology parameters of the ocean, and is suitable for deep oceans and shallow oceans.

The invention relates to a method for controlling damage of slope pre-splitting blasting digging based on a blast vibration test. The method comprises the following steps: establishing a statistical relation between the blasting particle peak vibration velocity at a plurality of blasting center distances and the damage depth under different altitude difference conditions by utilizing the blasting digging for a few front steps on the basis of the acoustic detection for a slope blasting digging damage area and the corresponding blasting vibration monitoring, and then utilizing the particle peak vibration velocity induced during the slope bench blasting process to forecast the depth of the digging damage area, and offering a control proposal for single-bump explosive quantity. After the relation between the particle peak vibration velocity and the slope blasting digging damage area is established according to a blasting vibration test result of the front steps and the acoustic detection for the damage area, subsequent steps are only subjected to blasting vibration monitoring, and geological data is combined for comprehensively analyzing and adjusting, so that the depth of the slope digging damage area can be determined and the operation is convenient, quick, high-efficient and economical. The rock slope blasting digging damage can be controlled by controlling the maximum single-bump explosive quantity. The method has high engineering popularization and application values.

The invention relates to a vibrating micro mechanical electric field sensor. The vibrating micro mechanical electric field sensor comprises a base and a sensitive layer and a shielding layer which are arranged on the base. The shielding layer comprises a movable structure and a fixed comb tooth structure, wherein the movable structure comprises a rectangular mass block, comb teeth and supporting beams, wherein a gap is reserved at the center of the rectangular mass block; the comb teeth are arranged around the mass block; and the supporting beams are connected with four end corners of the mass block. According to the invention, a parallel-plate capacitor can be utilized to load static electricity to tune the resonant frequency of the movable structure in the shielding layer; the vibrationdamping aiming at the movable structure in the shielding layer is tuned by the differential feedback of a vibration velocity signal; the normal pressure packaging of the vibrating micro mechanical electric field sensor is implemented; the high sensitivity can be implemented and the stability of an output signal can be improved; and the key problems of compensation on a manufacturing error, packaging, stability of the output signal and the like in an existing micro mechanical electric field sensor are solved.

The invention provides a blasting vibration predicting method, which comprises the following steps of: firstly, determining a reference blasting hole and a plurality of vibration measuring points, and placing vibration meters on each vibration measuring point; blasting the reference blasting hole to obtain blasting vibration waveforms having different distance points; and finally, executing a blasting vibration waveform predicting process. In the prediction process, actual blasting vibration test data is obtained firstly, the blasting vibration waveforms and migration stacked delay time of each blast hole on a predicting target point are then calculated according to distance from the predicting target point to the each blast hole and the reference blasting hole, and the vibration waveform of the predicting target point can be obtained based on a vibration wave stacking principle. A blasting vibration predicting result which is obtained by adoption of the method really shows an influence of a topographic condition of a field on blasting vibration, and the integral vibration waveform of the predicting target point can be obtained; a predicted vibration velocity peak value of waveform particles is quite approximate to an actually-measured vibration velocity peak value, and a time difference between the predicted vibration velocity peak value and the actually-measured vibration velocity peak value is also quite small; and an analysis result is accurate and reliable, so that adjustment of a blasting scheme can be better guided.

The invention provides a line spectrum signal object automatic detection method based on a single-vector submerged buoy. Sound pressure and vibration velocity signals of a vector hydrophone are obtained through the single-vector submerged buoy, and sound pressure and vibration velocity channel signals are taken as input, and quantity, frequency and orientation information of line spectrums beyond a threshold is obtained through primary detection; a primary detection result is taken as input of secondary detection, secondary dynamic accumulation is carried out on the multiple line spectrums beyond the threshold in terms of time, and the dynamic accumulated number of each line spectrum and buffer memory information of frequency and orientation information of the line spectrums are obtained; an automatic line spectrum tracking program is started on stable line spectrums; multiple line spectrums from the same object are merged; and an object quantity and an object orientation result are output. According to the invention, by making full use of the advantage of high signal-to-noise ratio of line spectrum detection, multiple unstable factors of the line spectrums can be overcome, and automatic detection of line spectrum objects is realized.

The vibration sensor is composed of magnet and winding. Characters are that when sensor induces external vibration, relative motion between magnetic suspended magnet and magnet fixed inside sensor occurs. Vibration of suspended magnet causes change of flux through coil. Based on Faraday law of electromagnetic induction, coil generates induction electromotive force being direct proportion to vibration velocity. Features are: simple and compact structure without need of metal reed and spring for fixing suspended magnet, wider induced vibration frequency spectrum. The disclosed vibration sensor is new type passive speed type vibration sensor.

The invention relates to the field of noise, in particular to a sound field separation and reconstruction method applicable to sound field separation and reconstruction of large sound sources. The sound field separation and reconstruction method comprises the following steps of: acquiring sound pressure and normal particle vibration velocity on a measuring surface; performing zero filling extension on the measuring surface positioned between two sound sources; acquiring transfer matrixes between the extended measuring surface and surfaces of the two sound sources, namely sound source faces; building a transitive relation between the sound pressure and the normal particle vibration velocity on the measuring surface; and acquiring the sound pressure and the normal particle vibration velocity of the first sound source face and the sound pressure and the normal particle vibration velocity of the second sound source face. A sound field is separated and reconstructed by using the single-measurement-surface and local near-field acoustical holography method. The sound field separation and reconstruction method has the characteristics of simplicity, short calculation time and high calculation efficiency, and can be widely applied to the measurement of near-field acoustical holography, the measurement of material reflecting coefficients, the separation of scattering sound fields and the like of large-size sound-source sound fields.

The present invention belongs to a technique for correlating the dynamic balance of the flexible rotor, and relates to a dynamic balance correcting method of the flexible rotor. The present invention adopts a ''pasting block at the center and end'' method of pasting balance block at the middle and two ends of the flexible rotor, and adopts the methods of selecting an appropriate rotary speed in a segment of rotation speed range before the interface rotary speed for static balancing, multiple cross section correcting, measuring speed with double frequency of the vibration velocity, monitoring with a radar chart, vectogram correcting and analyzing and laser monitoring for reducing the vibration, the vibration speed of the flexible rotor is effectively reduced and the optimum balance rotary speed can be founded out, the couple unbalance that the primary inertia rotor and rotor line cross at the gravity center is prevented to form in the balancing procedure, the part generating the unbalance amount is found out and the correction is executed pointedly.

The invention relates to a method for predicting peak vibration velocities of shallow-buried tunnel blasting construction surface particles. The method comprises the following steps of: firstly obtaining a peak particle vibration velocity theoretical equation under a porous initiating condition on the basis of a principle that porous blasting is equivalent to single-hole blasting, and correcting the peak particle vibration velocity theoretical equation; carrying out linear regression analysis on a peak particle vibration velocity of a measurement point, fitting parameters, topography and geology-related coefficients and blasting vibration attenuation indexes, and substituting the parameters, the coefficients and the indexes into the peak particle vibration velocity theoretical equation under the porous initiating condition; and finally substituting a known blast hole radius, an explosive density, a charging diameter and a distance between a surface particle and a blasting source into the peak particle vibration velocity theoretical equation so as to calculate a peak vibration velocity of the surface particle. According to the method, the existing single-hole blasting theoretical equation is corrected to obtain the peak particle vibration velocity theoretical equation under the porous initiating condition, so that the influences, on the peak vibration velocity, of explosive nature, rock performance and charging parameters can be reflected, and the blasting peak vibration velocities of fixed points on the surface can be calculated according to the practical blasting parameters and geological conditions.

The invention discloses complex titanium base grease and a method for preparing the same, which relates to grease and a method for preparing the same. The invention solves the problems that: the prior grease causes the vibration velocity of bearings to be unsteady, and has noises. The grease is prepared by base oil, thickening agent and additive. The method is as follows: 1. the base oil, the thickening agent and the additive are weighed; 2. the weighed thickening agent is mixed and stirred with one third of the base oil, the mixture is subject to the temperature rise and then heat preservation; 3. the mixture treated by the step 2 is subject to the temperature rise, and heat preservation for 0.5 to 5 minutes at a stirring speed of between 15 and 60r/m; 4. the mixture treated by the step three 3 is added with the remaining two-third base oil and is stirred and cooled, and then the additive is added into the mixture to grind to prepare the grease. With the grease, the vibration velocity of the bearings is as follows: the low frequency velocity is less than or equal to 30 mu m/s, the intermediate frequency velocity is less than or equal to 19 mu m/s, and the high frequency velocity is less than or equal to 28 mu m/s; and the vibration velocity is steady, and no noise exists.

The invention relates to a rapid broadband frequency domain beamforming method based on an acoustic vector sensor uniform linear array. The method comprises the following steps of: firstly, receiving spatial signals through the acoustic vector sensor uniform linear array to obtain time domain signals of all array elements, wherein the time domain signals comprise time domain acoustic pressure signals and time domain vibration velocity signals, and performing Fourier transform on snapshot data needed to be processed so as to obtain a corresponding frequency domain signal; secondly, performing zero fill on the acoustic pressure signals and the vibration velocity signals of all the array elements in a space domain according to a frequency band range needed to be processed, performing fast Fourier transform (FFT) on the signals in the space domain, and transferring a zero frequency component of the transform result to a spectrum center; thirdly, performing alignment correction and corresponding linear addition on beam and space domain Fourier results at each frequency point of bandwidth needed to be processed according to a frequency-beam grid corresponding to the acoustic pressure signals and the vibration velocity signals so as to obtain beamforming results of different frequency points; and finally, synthesizing beamforming results of different frequencies to obtain power output of a linear array spatially.

The invention discloses a real-time sound field separating method for measuring by the adoption of single-side sound pressure and vibration velocities. The real-time sound field separating method for measuring by the adoption of the single-side sound pressure and the vibration velocities is characterized in that a measuring plane is arranged between a target sound source and an interface sound source, and sound pressure time-domain signals and vibration velocity time-domain signals of grid points on the measuring plane are synchronously collected; two-dimensional space Fourier transform is respectively conducted on the sound pressure time-domain signals and the vibration velocity time-domain signals to acquire sound pressure time-domain wave number spectra and vibration velocity time-domain wave number spectra of wave numbers; then sound pressure time-domain wave number spectra independently radiated on the measuring plane by the target sound source are timely separated through the sound pressure time-domain wave number spectra, the vibration velocity time-domain wave number spectra and a known time-domain impulse response function, and accordingly sound pressure time-domain signals independently radiated on the measuring plane by the target sound source are acquired. Only one measuring plane is needed, a deconvolution process does not exist, and therefore the real-time sound field separating method for measuring by the adoption of the single-side sound pressure and the vibration velocities is simple in achieving mode, high in stability and capable of being used for conducting field analyses of the time-varying radiation characteristic of the target sound source under the noise interference environment.

The invention relates to an on-line vibration detection device and method for an equipment state of a hot finishing mill, belonging to the technical field of on-line detection of roll steel. The signal output ends of the vibration velocity and vibration acceleration of the device are respectively connected with the input end of a central processing module, and the output end of the central processing module is externally connected with an upper computer and an alarming device; an equipment fault can be checked through vibration detection in working state through a storing step, an inputting step, a collecting step, an operation step, a determining step and a revising step; and false alarming due to temporarily irregular impact and vibration such as steel-engaging impact and steel-throwing impact when the hot finishing mill works can be effectively reduced, and the authenticity of alarming can be improved.

The invention discloses a low-orbit flexible satellite attitude tracking control method based on a sliding-mode observer, relates to a low-orbit flexible satellite attitude tracking control method based on a sliding-mode observer, and aims at solving the problems that an existing low-orbit flexible satellite is low in satellite attitude tracking control accuracy due to relatively large aerodynamic interference torque and vibration of flexile components. The low-orbit flexible satellite attitude tracking control method based on the sliding-mode observer comprises the following steps: building a geocentric inertial coordinate system and a satellite body coordinate system; building a state space expression, and determining an upper bound of an interference signal received by the observer; solving a gain matrix of the observer, a matching matrix of the observer and a Lyapunov equation matrix variable; observing to obtain an estimated mode vibration velocity value of the sliding-mode observer and an estimated mode vibration state value of the sliding-mode observer; rewriting a kinetic equation of a flexible satellite attitude into an error attitude tracking control model; determining a sliding-mode term gain of the control law, and carrying out tracking control on the error attitude tracking model by adopting the siding-mode control law according to measured satellite attitude quaternion, attitude angular velocity information and estimated mode quantity value. The low-orbit flexible satellite attitude tracking control method is applied to satellite attitude tracking control.

The invention belongs to the acoustic vector communication field, and particularly relates to a vector circular matrix steady broadband MVDR estimation method. The method comprises steps of performing sub-band decomposition on acoustic pressure data and vibration velocity data received by the two-dimension circular array and generating a broadband frequency domain signal matrixes of the acoustic pressure and vibration velocity to obtain a broadband frequency domain snapshot data matrix of the vector matrix, generating vector cross-spectral matrix on all sub-bands, setting pace lengths, performing azimuth scanning, constructing a vector array guide vector on the sub-band, selecting a focusing reference frequency point and constructing the vector array focusing guide vectors on the same azimuth, adopting a coherence signal subspace CSS focusing transformation method to obtain a vector array focusing transformation matrix, obtaining a broadband focusing covariance matrix, obtaining an optimum vector and array average output power after optimization, and determining sound wave source according to the spectrum peak position of the spatial spectrum. The Acoustic vector circular matrix steady broadband MVDR orientation estimation method applies stable constrained optimization and improves the spatial spectrum resolution.

The invention provides a piezoelectric underwater sound transducer acoustic radiation mode measurement method and system based on combination near-field acoustical holography. In the method, the combination near-field acoustical holography is utilized to reestablish sound field, sound pressure and radiation surface vibration velocity; on the basis of an acoustic radiation operator matrix obtained based on measurement data and with the sound field radiation theory being combined, the acoustic radiation power of a piezoelectric underwater sound transducer is expressed to be a positive definite quadric form; and positive definite and conjugate performance of the matrix are utilized to obtained an acoustic radiation mode of the structure. The system comprises a glass water tank, an industrial control computer with PXI bus, a transducer excitation module based on the PXI bus, a sound pressure and vibration velocity acquisition module and a three-dimensional motion platform. The method and system in the invention break the limitation that acoustic radiation mode in the current complex underwater structure can only be solved numerically, provide a new idea for research on the piezoelectric underwater sound transducer, and also provide basis for structure optimization of the piezoelectric underwater sound transducer.

The invention belongs to the underwater sound direction-finding field and relates to a sound pressure and vibration velocity cross-spectrum method-based vector array port and starboard discrimination method. The method includes the following steps that: step (1) after received sound pressure signals are converted into frequency-domain signals, frequency-domain broadband conventional beamforming processing is carried out on the frequency-domain signals, so that an original spatial spectrum matrix can be obtained, wherein the spatial spectrum matrix is a matrix of an outputted spatial spectrum type; step (2) bidirectional one-order recursive filtering processing is performed on the obtained original spatial spectrum matrix, so that a smoothed spatial spectrum can be obtained; and step (3) according to the smooth spatial spectrum, DT decibels are increased based on the smooth spatial spectrum, so that a threshold for spectral peak screening can be obtained. According to the method of the invention, peak screening is carried out on the spatial spectrum; direction estimation is carried out on signals in a spectral peak range; subtractive suppression is carried out on pseudo peak measurement through comparing an estimated result with a spectral peak position; and therefore, the problem of port-starboard ambiguity under a low signal-to-noise ratio can be solved, and weak target detection under a homogeneous noise background can be improved.

The invention discloses an active suspension support vector machine generalized compound inverse controller and a construction method thereof. The controller comprises an active suspension system, an optimal controller and a linear motor support vector machine generalized composite inverse controller. The construction method includes forming a compound control target by cascading a current inverter before a linear motor, forming a support vector machine inverse system by the support vector machine and two integration elements, and combining a linear controller with the support vector machine inverse system and the current inverter to form the support vector machine generalized compound inverse controller. A sensor of the active suspension system is used for extracting suspension vibration signals online, and the optional controller is used for calculating the optimal control force and the vibration velocity. The support vector machine compound inverse controller controls the linear motor to output corresponding electromagnetic force and velocity in real time according to the control force and the suspension vibration velocity given by the optimal controller and the electromagnetic thrust and velocity fed back by the linear motor, thereby realizing system linearization, decoupling and degree reduction while achieving good effect and real-time performance of the active suspension.

The invention discloses a single-piston-rod damper and belongs to the technical field of structural vibration control devices. The single-piston-rod damper comprises a cylinder which is divided into a working chamber and a compensation chamber, the working chamber and the compensation chamber are separated from each other through a floating piston which is sealed together with the cylinder, and the working chamber is filled with shear thickening fluid (STF); one end, with the tip being connected with a working piston, of the piston rod is arranged in the working chamber in the cylinder, and the other end of the piston rod is arranged outside the cylinder and connected with an upper connecting part; and an elastic part is arranged in the compensation chamber, one end of the elastic part is connected with the floating piston, and the other end of the elastic part is connected to a rubber piston arranged at the end of the cylinder. When the shearing rate is high and the instantaneous vibration velocity in the working chamber is high, shear thickening of the STF occurs to generate damping force, so that the anti-impact vibration-reduction effect of engineering structures is achieved; and when the shearing rate is low and the instantaneous vibration velocity in the working chamber is low, the elastic part in the compensation chamber elastically compensates for the initial rigidity of the damper, so that vibration reduction and energy dissipation of the engineering structures are achieved. The single-piston-rod damper is provided with the elastic compensation chamber to provide appropriate compensation rigidity, and the anti-impact vibration-reduction effect of the damper is achieved.