57 results about "Transfer path analysis" patented technology

The invention relates to a detection method in the ship test technology field and particularly relates to an outfield acoustically-driven ship vibration and noise transmission path analysis method. The method comprises steps that, information of inner and outer acceleration sensors of a ship and an outer hydrophone measurement channel of the ship are set; according practical measurement positions of various vibration sensors, grading classification of vibration measuring points is carried out according to an equipment machine foot, a vibration isolation device, a piping system, an inner ship side and an outer ship side; a high power sound source is employed, according to main characteristic frequency spectrums of radiation noise, a sound signal is emitted to excite warship casing key positions, and data acquisition is carried out; transmission path contribution amount analysis is carried out according to calculation results, for the transmission path contribution amount analysis, a response component generated at an assessment point of each path is contrasted with the overall response, and the contribution amount of the response component of each path in the overall response is calculated. Through the method, a problem of excitation difficulty in the ship can be solved, and the method has certain reference values for subsequent ship transmission path analysis.

The invention relates to an indoor noise source locating method based on beam forming and transfer path analysis. The indoor noise source locating method comprises the steps of: 1), collecting an acoustic pressure signal at a target position under a normal working condition; 2), finding out a maximal acoustic pressure level frequency band by spectrum analysis; 3), dividing regions of possible acoustic sources in a space; 4), finding out the maximal noise source position in each acoustic source region in the space by using a time domain BF (beam forming) method; 5), judging whether all regions are identified completely or not, if so, executing a step 6), and if not, returning to the step 4), 6), measuring path information and contribution degree from each maximal noise source to the target position by using a TPA (transfer path analysis) method, and the like. Compared with prior art, the indoor noise source locating method, disclosed by the invention, has the advantages that: the acoustic source can be accurately located; the work load of the TPA can be reduced, the noise source with the maximal control position can be found out by less TPA work load and the like.

The invention discloses an improved operating condition transfer path analysis method capable of increasing precision. The method comprises the following steps of step1, collecting operating condition excitation and response signals; step2, using a wavelet noise reduction technology to carry out noise reduction processing on the collected signals; step3, using the signals after noise reduction processing to calculate a frequency response function; step4, calculating a load; step5, calculating a transfer path contribution amount. The method possesses advantages that transfer path contribution amount calculating precision is effectively increased and so on.

The invention discloses a method for evaluating the power supply reliability of a power distribution network and belongs to the field of power distribution network power supply. The method includes: reading the original data firstly and enumerating corresponding fault events for grid equipment; searching a transformer to obtain power supply interrupted regions caused by faults, conducting fault state simulation and distinguishing the recoverable power supply region from the unrecoverable power supply region; for each fault event of the recoverable power supply region, acquiring the load transferring path through the load transferring path analysis; conducting load flow calculation, if the load flow is overload and the load transferring is not successful, acquiring a new load transferring path; and calculating the reliability index of each load point and the whole power distribution network according to the recoverable power supply region and the unrecoverable power supply region after faults. The method can more accurately and comprehensively evaluate the power supply reliability of the power distribution network so that the level which the urban power grid can reach in the aspect of the power supply ability, the present problems and the development prospect can be deeply realized.

A method (200) is described for the characterisation of vibrational and/or acoustic transfer path related data of a physical system (100). The physical system (100) thereby may be any physical system wherein vibration or acoustics may play a role. The method (200) comprises receiving (210) input data for at least one input point of the physical system and/or response data for at least one response point of the physical system (100). The method (200) further comprises receiving (220) at least one system response function between the at least one input point and the at least one response point indicative of the transfer of vibration and/or acoustic signals. The method (200) also comprises applying (230) at least one parametric model characterising at least one load on the physical system as a function of said input data, whereby the parametric models are identified from said input data and/or response data and said physical system response functions. The method (200) may have as output a parametric model for the loads present on the system, the determined loads present on the system or the transfer path contributions, e.g. per order or per frequency, and for at least one of the response points.

The invention discloses an inverse substructure technology-based transmission path analysis method. The method comprises the steps of 1, sensing and acquiring an excitation signal and a response signal; 2, sensing and acquiring a frequency response function; 3, calculating the dynamic stiffness; 4, calculating the load; 5, calculating the contribution of a transmission path. The method overcomes the defect in the prior art that the test result of dedicated equipment is different from the state of a real vehicle. Therefore, the obtained contribution of the transmission path is enabled to be much closer to the real state of the overall vehicle.

The invention discloses a method for detecting a vehicle noise source. The method for detecting the vehicle noise source comprises the steps that a vibration signal at a possible excitation source position, a noise signal at the possible radiation source position and a noise signal at a target point are measured under a steady-state working condition of a vehicle, a multi-input single-output modelis established by using a transfer path analysis method, and the number and position of independent radiation sources/excitation sources and the contribution of each radiation source/excitation source are determined. Compared with a traditional experimental analysis method, the operation flow of the vehicle vibration noise source detection is simplified without the need for a transfer function test; the transfer path analysis method based on the working condition test is adopted, the number and position of main noise radiation sources in the environment of serious aliasing noise in the vehicle can be detected, and the contribution amount of each radiation source is determined, so that the method for detecting the vehicle noise source is more practical; and in addition, detection is carried out for the steady-state working condition, operation is simple and convenient, time is saved, and a noise source transfer path can be identified without the need of a decoupled system.

The invention discloses a damping singular value decomposition-based method for analyzing transmission paths under a running condition. According to the adopted technical scheme, the method comprises the steps of designing a test condition for a to-be-analyzed mechanical system and measuring test condition data; constructing an equation through the acquired test condition data; solving the equation by applying a damping singular value decomposition algorithm to obtain a transmissibility function matrix; measuring a reference point response signal of the to-be-analyzed mechanical system under an actual working condition; multiplying the reference point response signal measured under the actual working condition by the identified transmissibility function matrix to obtain a transmission path contribution result; and sorting different path contributions to obtain contribution proportions of the transmission paths, thereby finishing the analysis of the transmission paths under the running condition. According to the method, the problem of truncation errors caused by performing truncation on a singular value of a coefficient matrix in conventional analysis of the transmission paths under the running condition is solved, so that the transmission path contribution calculation precision is improved.

The invention relates to a distribution network 10 kV line load transfer path on-line selection system and belongs to the technical field of electric power. The system comprises a master server and working stations. The maser server comprises a data interface, a storage and a processor. Each working station comprises a data interface and a processor. Each data interface comprises a data interface module, the storage comprises a database module, and each processor comprises a topology module and a transfer path analysis module. Each data interface module obtains CIM file data and E file data from an SCADA system. A data analysis module analyzes CIM files and E files, and then the analyzed files are stored in the database module. Each topology module is responsible for topology generation and simplification, and topology data are generated and simplified according to device parameters and the connection relation. Each transfer path analysis module analyzes the load transfer path in each 10 kV line. Compared with the prior art, the distribution network 10 kV line load transfer path on-line selection system has the advantages of being high in calculation speed, high in practicability and high in accuracy and being applied in multiple aspects.

The invention belongs to the noise forecasting filed and especially relates to a ship and ocean platform structure broadband line spectrum vibration noise time-frequency integration forecasting method. The method is characterized by acquiring the time domain or frequency domain loads of a ship and ocean platform equipment; then, establishing a ship and ocean platform structure vibration noise analysis finite element model, and taking the time domain vibration signal a of the ship and the ocean platform equipment as input, reasonably controlling a time increment step deltat and model calculation time Tt, carrying out ship and ocean platform structure vibration noise simulation calculation, acquiring ship and ocean platform structure broadband response x(t), and carrying out FFT conversion on steady-state response to obtain ship and ocean platform structure frequency domain response; and based on the above condition, carrying out the dominant transmission path analysis of the ship and the ocean platform for a frequency point with large vibration response and the frequency point which needs to be focused on, and realizing the rapid quantitative analysis of a ship and ocean platform broadband line spectrum vibration noise. By using the method, a line spectrum capture capability is good, solving efficiency and forecasting precision are high and an application prospect is wide.

Disclosed is a method for identifying a frequency response function of a split-free substructure based on an in-situ measurement frequency response function. First, components in a mechanical system are classified into active components, passive components and elastic components, a coupled frequency response function matrix is established, and then a frequency response function of the decoupled mechanical system is obtained based on a passive component frequency response function prediction formula. The method predicts a decoupled mechanical frequency response function by adopting a coupled mechanical frequency response function based on a "source-path-acceptor" model, thereby overcoming the problem that the existing technology cannot calculate the frequency response function between random degrees of freedom of the mechanical substructure, improving the calculation precision of the frequency response function and laying a foundation for vibration transfer path analysis of the mechanical system.

The invention relates to a whole vehicle transmission path analysis test method based on a network diagnosis algorithm. The method comprises the steps of carrying out noise source power test and calculation based on a power substitution method; testing a noise direct transfer function; testing a noise composite transfer function; measuring the reverberation time in a vehicle; and on the basis of the test result, carrying out the whole vehicle transmission path data analysis of the network diagnosis algorithm. According to the method, the contribution levels of various noise sources of the whole vehicle can be scientifically and effectively analyzed, the contribution amounts are sorted, and the noise sources, such as engines, transmissions, intake and exhaust, tires, etc., are optimized ina targeted manner. According to the method, the acoustic package transmission paths of the whole vehicle can be accurately analyzed, the transmission paths are sorted, the weak transmission paths areoptimized in the targeted manner, the research and development cost is saved, and the research and development efficiency is improved. According to the present invention, the air sound and structuralsound of the vehicle can be accurately separated, and the direction is pointed out for the development of the acoustic performance of the whole vehicle. According to the method, the noise characteristics of the vehicle can be accurately analyzed, and guiding significance is provided for the vehicle platformization development.

The invention discloses a vehicle transmission path obtaining method and device, and the method comprises the steps: obtaining an in-vehicle noise signal, and carrying out the transmission path analysis of the in-vehicle noise signal; solving the difference between the amplitude value of the in-vehicle noise signal and a target noise value corresponding to the same frequency point, and obtaining a first difference curve; solving the difference between the amplitude of the in-vehicle noise signal and the noise amplitude value generated by each transmission path corresponding to the same frequency point, and obtaining a second difference curve; and obtaining the contribution coefficient of the transmission path corresponding to the frequency point according to the relation between the differences, corresponding to the same frequency point, of the first and second difference curves and the corresponding preset threshold values. The method and device can quickly obtain the contribution of each transmission path to the whole in-vehicle noise.

The invention relates to a noise recognition method for a high-end textile manufacturing machine based on transfer path analysis, and the method comprises the following steps: measuring a frequency-response function of transfer paths of a plurality of excitation sources; measuring the sound pressure and a working load under the measurement work condition; and calculating a noise contribution amount through the acceleration of the excitation sources, the sound pressure under the work condition and the working load. The method can achieve the recognition of the amplitude of main noise of the high-end textile manufacturing machine under the work condition and the noise contribution amount of a main sound generating mechanism.

The invention provides a method for decomposing an automobile interior noise development objective into subsystem design indexes. According to the method, the subsystem design indexes are continuously adjusted to approach a complete vehicle development objective by utilizing a transfer path analysis synthesis algorithm through step-by-step iteration, and in the process, engineering actual constraints are taken into account, so that accurate conversion from the complete vehicle development objective to the subsystem design indexes is achieved. The method is simple, the objective decomposition efficiency of automobile interior noise is higher, the uncertainty relying on personal experience is avoided, and the problem that an objective is difficult to decompose in the initial stage of automobile development is better solved.

The invention discloses a system and a method for simulating engine excitation. A master control computer controls a signal generator to output a cylinder pressure signal when a real engine runs, and a power amplifier drives an engine excitation source generating device to simulate the excitation of the real engine. The engine excitation source generating device receives the cylinder pressure signal and generates excitation force to simulate vibration and sound excited by the engine. A 'source-path-response 'model is established, a force vibration transfer function and a force sound transfer function corresponding to the structure are acquired, and an engine transfer path analysis test is performed. On the premise of guaranteeing stable output of excitation source signals required by a test, the structure is greatly simplified, the requirement that the excitation source is convenient to disassemble and assemble is met, excitation simulation of the engine under different working conditions can be achieved, and excitation simulation of other multi-cylinder engines or single-cylinder engines can also be achieved. And partial NVH tests related to the engine can be carried out in a laboratory range.

The object of the invention is to provide a method, a device and an automobile for determining a main transmission path of sound of a tire cavity, so as to solve the problem that the main transmissionpath of sound pressure response points in a vehicle compartment cannot be quickly determined in the prior art. The method for determining the main transmission path of the sound of the tire cavity comprises the following steps of: determining a target wheel which contributes the most to the sound of the tire cavity; performing a transmission path analysis on a quarter suspension system corresponding to the target wheel; determining the main transmission path of the corresponding sound of the tire cavity of each sound pressure response point located in the vehicle compartment under the condition of the predetermined test condition that causes the most pronounced sound of the tire cavity.

The invention discloses an operation-condition transfer path analysis method based on a Landweber iteration method. Based on test operation condition designing and test operation condition data measurement, a transmissibility functional matrix is reversely solved through observed reference-point response signals and target-point response signals. The operation-condition transfer path analysis method includes the following steps that 1, reference-point and target-point response signals under a test condition are collected by arranging sensors, and observed signals are subjected to fast fouriertransform; 2, an iteration scheme suitable for the ill-posed Landseber iteration method is selected and used for estimating the transmissibility functional matrix; 3, the obtained transmissibility functional matrix is reciprocally multiplied by reference point responses measured in actual conditions, and the contribution quantity and the total contribution quantity of all transfer paths are calculated. According to the operation-condition transfer path analysis method, in the process that the transmissibility functional matrix is solved, and due to small disturbance of original data, large disturbance of obtained solutions can be avoided; the good noise-resistant capacity is achieved, the fitting degree of the obtained solutions is high, and the excellent actual situation reflecting capacity is achieved.

The invention discloses a method for testing sound propagation experiments of rai car structures under carload semi-anechoic room environment, and belongs to the technical field of acoustic experiments. According to the method, a carload semi-anechoic room which is enough to contain a tested car model is constructed according to an overall dimension of a train; a single carriage of a rail car under a prepared state is put in the carload semi-anechoic room; and structural vibration noises generated to passenger room carriages by bogie noises and transfer paths of the structural vibration noisesare analyzed by utilizing an existing transfer path analysis method for structural vibration noise components. According to the method, influences, on test results, of low-frequency noises in structural sound propagation test site environment are avoided, and a technical acceptance standard for a free field deviation value of the carload semi-anechoic room and optimum position parameters, relative to specific local parts, of noise sampling points in the passenger room carriage are definitely given, so that structural sound propagation experiments can obtain optimum experiment results.

The embodiment of the invention discloses an analyzing method for a transferring path based on an absolute transferring rate function. By analyzing contribution degree through the absolute transferring rate function, the heavy loading identification work in the traditional transferring path analysis is avoided, and the practical operational process in engineering is simplified, thereby improving the analysis efficiency of the transferring path and shortening project period. The analyzing method is suitable for transferring path analysis condition of low-frequency and high-frequency. According to the method of the invention, the method comprises the following steps: providing an advanced transferring path analysis method based on the absolute transferring rate function, namely, the analysis of calculating the transferring rate function of the system obtained by measurement to obtain the absolute transferring rate function and subsystem contribution degree; processing the transferring rate function by a normalization principle and identifying the obtained contribution degree result by taking a principle component analysis method.

The invention provides a noise prediction method for a power assembly, and belongs to the field of vehicle noise control. The noise prediction method comprises the following steps: carrying out a multi-working-condition vibration noise test on a test vehicle provided with a first target test point; according to the data of the first target test point, obtaining a first transfer function of the passive end of each power assembly suspension on the test vehicle to the noise in the vehicle by using a working condition transfer path analysis method, a second transfer function of each power assembly near field to noise in the vehicle and a third transfer function of each power assembly suspension from an active end to a passive end thereof; performing a rack NVH test of a target working condition on the target power assembly provided with the second target test point; and calculating the total noise value of the target power assembly according to the data of the second target test point, the first transfer function, the second transfer function and the third transfer function. According to the noise prediction method for the power assembly, the later vehicle adjustment period can be shortened, and the vehicle research and development cost is reduced.

The invention discloses an output-based semi-submersible ocean platform energy transfer path analysis method, which comprises the following steps of: arranging acceleration sensors at a vibration source and a target point to form an array, performing characteristic component analysis on a signal at the vibration source by utilizing a short-time Prony method based on a state space model, and determining a characteristic frequency; dispersing signals at a vibration source and a target point, introducing a first-order matrix differential equation by utilizing a complex exponential decomposition technology, and extracting signals at a characteristic frequency; solving a correlation coefficient of the reconstructed signal near the characteristic frequency, and extracting a characteristic component; calculating the amplitude of the characteristic component, substituting the amplitude into a formula to solve the transmissibility, and drawing the transmissibility spatial distribution map spatially to obtain the change rule of the transmissibility of the characteristic signal component in the whole spatial range so as to reveal the characteristic signal transmission condition. The method only depends on output response signals obtained through testing, and measurement of exciting force and a transfer function in a traditional method is avoided.

The invention provides an in-vehicle air noise target decomposition method based on a transfer path analysis theory. The method comprises the following steps: S1, measuring prototype vehicle sound source sound power and acoustic transfer function data, establishing a transfer path analysis model, and calculating in-vehicle air noise based on a transfer path analysis theory; and S2, establishing an air noise target decomposition optimization model, customizing a target function according to an actual demand by taking the acoustic transfer function of each path as a design variable and the air noise target in the vehicle as a constraint condition, and performing automatic optimization by adopting a multi-island genetic algorithm to obtain an optimal acoustic transfer function scheme. The method has the advantages that the transmission path analysis and automatic optimization theory is applied for the first time in the field of in-vehicle air noise target decomposition of the automobile, a large number of tests in the traditional experience development process are omitted, the development time and production cost of the whole automobile are saved, meanwhile, the optimal solution of the transmission path can be found through an optimization algorithm, and the phenomenon of performance waste caused by unreasonable performance distribution of the factor system is avoided.

The invention discloses an equipment operation condition transmission path parameter calculation method and system, and the method comprises the steps: determining the position of an excitation sourceand a transmission path according to the mechanical structure features of a to-be-tested object, determining the number of reference points and the optimal installation position through employing a reference point optimization method, and guaranteeing the linear irrelevance of different conditions under test condition parameters, acquiring vibration response signals of the final reference point installation position and the target point installation position under stable excitation of the test working condition parameters, and performing crosstalk removal processing on the acquired vibrationresponse signals; the vibration response signals after crosstalk removal processing are used for carrying out least square support vector regression training on the operation condition transmission path analysis model to obtain a transmission function matrix, the problem of matrix morbidity of a traditional operation condition transmission path analysis method is avoided, condition data can be completely reserved. And good generalization performance can still be maintained in a test environment with a complex environment.