CN116484493A - Engine multisource load identification method, device and equipment - Google Patents
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Abstract
The invention discloses a method, a device and equipment for identifying engine multisource loads, relates to the technical field of load identification, and aims to solve the problems of large theoretical modeling error and low load identification precision in the prior art. Comprising the following steps: the method comprises the steps of enabling space distribution load of a main load source of an engine to be equivalent to concentrated load, establishing an engine system comprising the concentrated load, carrying out sensor layout optimization of the engine system comprising the concentrated load based on a coherent function and a frequency response function matrix condition number, constructing an engine system model, and carrying out an engine ground vibration test to obtain an experimental result; based on experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure. The problem of large theoretical modeling error is avoided by adopting the test modeling method, the load identification precision is improved by introducing a regularization idea and optimizing the sensor layout, and the test cost is effectively reduced.
Description
Technical Field
The present invention relates to the field of load identification technologies, and in particular, to a method, an apparatus, and a device for identifying multiple source loads of an engine.
Background
The liquid rocket engine (hereinafter referred to as engine) can generate huge vibration in the working process, the space-time distribution difference and the randomness of the vibration energy are large, and the fatigue failure of the structure is easy to cause, thereby influencing the launching task. In the working process of the engine, the vibration response of each main load interface can be obtained through test-on-board rather than excitation, and the vibration response can not be directly used for the dynamic strength design and analysis of the engine structure, so that the vibration load generated in the working process of the engine can be accurately identified, load environment input conditions are provided for the structural strength and fatigue life evaluation of the engine, and the vibration load interface vibration response method has important practical significance for the development of engine engineering.
Accordingly, there is a need to provide a more reliable engine multisource load identification method.
Disclosure of Invention
The invention aims to provide an engine multisource load identification method, device and equipment, which are used for solving the problems of large theoretical modeling error and low load identification precision in the prior art.
In order to achieve the above object, the present invention provides the following technical solutions:
in a first aspect, the present invention provides a method for identifying multiple source load of an engine, the method comprising:
the space distribution load of the main load source of the engine is equivalent to the concentrated load;
performing sensor layout optimization of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number;
constructing an engine system model based on a sensor layout optimization scheme, and developing an engine ground vibration test to obtain an experimental result;
based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
Compared with the prior art, the engine multisource load identification method provided by the invention comprises the following steps: the method comprises the steps of enabling space distribution load of a main load source of an engine to be equivalent to concentrated load, establishing an engine system comprising the concentrated load, carrying out sensor layout optimization of the engine system comprising the concentrated load based on a coherent function and a frequency response function matrix condition number, constructing an engine system model based on a sensor layout optimization scheme, and carrying out an engine ground vibration test to obtain an experimental result; based on experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure. According to the liquid rocket engine multi-source load identification method based on the test modeling method and the regularization theory, the problem of large theoretical modeling error is avoided by adopting the test modeling method, the load identification precision is improved by introducing the regularization idea and optimizing the sensor layout, and the test cost is effectively reduced.
In a second aspect, the present invention provides an engine multisource load recognition device, the device comprising:
the load equivalent module is used for equivalent of the space distribution load of the main load source of the engine into concentrated load;
the sensor layout optimization module is used for optimizing the sensor layout of the engine system comprising the concentrated load based on the coherence function and the frequency response function matrix condition number;
the ground vibration test development module is used for constructing an engine system model based on a sensor layout optimization scheme and developing an engine ground vibration test to obtain an experimental result;
and the multi-source load identification module is used for identifying multi-source dynamic loads acting on the engine structure by using a regularization method based on the experimental result.
In a third aspect, the present invention provides an engine multisource load recognition apparatus, the apparatus comprising:
the communication unit/communication interface is used for equating the space distribution load of the main load source of the engine into a concentrated load;
a processing unit/processor for performing sensor layout optimization of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number;
constructing an engine system model based on a sensor layout optimization scheme, and developing an engine ground vibration test to obtain an experimental result;
based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
In a fourth aspect, the present invention provides a computer storage medium having instructions stored therein that, when executed, implement the engine multi-source load identification method described above.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:
FIG. 1 is a schematic flow chart of an engine multi-source load identification method provided by the invention;
FIG. 2 is a graph showing the comparison of the engine multi-source load measurement and the calculated amplitude spectrum;
FIG. 3 is a graph showing the comparison of power spectral density functions of engine multisource load measurement results and calculation results;
FIG. 4 is a graph showing the comparison of the measured response to the calculated response amplitude spectrum of the engine;
FIG. 5 is a schematic diagram of a multi-source load recognition device for an engine according to the present invention;
fig. 6 is a schematic diagram of an engine multi-source load recognition device according to the present invention.
Detailed Description
In order to clearly describe the technical solution of the embodiments of the present invention, in the embodiments of the present invention, the words "first", "second", etc. are used to distinguish the same item or similar items having substantially the same function and effect. For example, the first threshold and the second threshold are merely for distinguishing between different thresholds, and are not limited in order. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.
In the present invention, the words "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.
In the present invention, "at least one" means one or more, and "a plurality" means two or more. "and/or", describes an association relationship of an association object, and indicates that there may be three relationships, for example, a and/or B, and may indicate: a alone, a and B together, and B alone, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, a and b, a and c, b and c, or a, b and c, wherein a, b, c can be single or multiple.
In the prior art, vibration load generated in the working process of an engine is accurately identified, and an engine dynamics model needs to be accurately established. During modeling, two methods, namely theoretical modeling and experimental modeling, are generally adopted. The theoretical modeling method adopts a large amount of simplification processing in the modeling process, so that modeling errors are easily introduced, and the solving accuracy of the dynamic model is further affected. The experimental modeling method can avoid errors caused by simplified processing in the theoretical modeling process, and a parameter identification method is adopted to establish the relationship between the input and the output of the structural dynamics system. Compared with a theoretical model, the dynamic model obtained by the experimental modeling method is more reliable, however, a complex system has larger measurement error, and the boundary condition and the environmental condition of the system are difficult to simulate, so that the method has weak guidance on solving the actual engineering problem.
Based on the method, a multi-source load identification method is established by combining test modeling and regularization methods, so that the problems of difficult engine vibration load identification and low solving precision are solved.
Next, the scheme provided by the embodiments of the present specification will be described with reference to the accompanying drawings:
fig. 1 is a schematic flow chart of a method for identifying engine multi-source load, as shown in fig. 1, the flow may include the following steps:
step 110: the spatially distributed load of the main load source of the engine is equivalent to a concentrated load.
The main load source may include a thrust chamber, a turbo pump, a gas generator; in this specification, the engine may be a liquid rocket engine.
Step 120: sensor layout optimization of an engine system including concentrated loads is performed based on a coherence function and a frequency response function matrix condition number.
The coherence function (coherency function) is also known as coherence, and the degree of linear correlation between the components at each frequency is achieved in both processes. The frequency response function (Frequency Response Function, FRF) is the ratio of the output response of the structure to the input excitation force. We measure the excitation force and the structural response caused by the excitation force (this response may be displacement, velocity or acceleration) simultaneously, transform the measured time domain data from the time domain to the frequency domain by Fast Fourier Transform (FFT), and transform the frequency response function to finally appear as complex form, including real and imaginary parts, or amplitude and phase.
Step 130: and constructing an engine system model based on the sensor layout optimization scheme, and carrying out an engine ground vibration test to obtain an experimental result.
Step 140: based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
The dynamic load can represent the load which is borne by an object under the influence of factors such as vibration, environment and the like in the motion process, the dynamic load comprises impact load (such as an air hammer) which acts rapidly in a short time, periodic load (such as an air compressor crankshaft) which changes periodically along with time and random load (such as an automobile engine crankshaft) which changes non-periodically, the multi-source dynamic load which acts on the engine structure is identified by a regularization method according to the ground test result of the engine, the applicability of the load identification method is verified by comparing with the actually measured load, and when the applicability of the load identification method reaches the preset requirement, the dynamic load of the liquid rocket engine is identified by adopting the load identification method.
The method of fig. 1, comprising: the method comprises the steps of enabling space distribution load of a main load source of an engine to be equivalent to concentrated load, establishing an engine system comprising the concentrated load, carrying out sensor layout optimization of the engine system comprising the concentrated load based on a coherent function and a frequency response function matrix condition number, constructing an engine system model based on a sensor layout optimization scheme, and carrying out an engine ground vibration test to obtain an experimental result; based on experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure. According to the liquid rocket engine multi-source load identification method based on the test modeling method and the regularization theory, the problem of large theoretical modeling error is avoided by adopting the test modeling method, the load identification precision is improved by introducing the regularization idea and optimizing the sensor layout, and the test cost is effectively reduced.
Based on the method of fig. 1, the examples of the present specification also provide some specific implementations of the method, as described below.
Optionally, before the optimization of the sensor layout of the engine system including the concentrated load based on the coherence function and the frequency response function matrix condition number, the method may further include:
determining the application position and the application form of the concentrated load;
an engine system including the concentrated load is built based on the location of application of the concentrated load and the form of application of the concentrated load.
In practical application, an engine load source is determined, a main load source (a thrust chamber, a turbopump and a gas generator) is separated to serve as a concentrated load application interface, test response signals are analyzed, load forms born in the working process of the engine are determined according to response data, and the concentrated load form is designed and applied according to the internal load form of the engine. The space distribution load of the main load source (thrust chamber, turbine pump and gas generator) of the engine is equivalent to the concentrated load applied to the engine structure, N concentrated load positions are determined according to the limitation of test space and test cost, in specific application, the concentrated load positions can be 3, and the value of N can be set according to the actual application requirement.
The engine system comprising the load source and the key components is established by using a test modeling method, and the sensor layout scheme is optimized, specifically, the rocket engine can be firstly installed and fixed, and then the engine excitation system comprising the load source and the key components is established. Specifically, device commissioning and calibration. Ensuring the normal operation of the data acquisition instrument, the acceleration sensor and other equipment; background noise test, which ensures that the acquired signal has higher signal-to-noise ratio; and 3 vibration exciters apply excitation simultaneously to develop an engine ground vibration test, and excitation and response data are measured. When the engine is installed and fixed, the engine can be installed on a test bed to simulate the working boundary conditions of the engine. When the engine excitation system is built, a suspension rack of the vibration exciter can be built beside the engine test rack, the vibration exciter is suspended on the rack through the lifting hook and the nylon rope, the height of the vibration exciter can be conveniently adjusted, and the vibration exciter can vertically apply exciting force at the concentrated load applying position.
Further, determining the application position of the concentrated load and the application form of the concentrated load may specifically include:
analyzing the test response signal, determining the load form born in the working process of the engine according to the response data, and designing a concentrated load form according to the internal load form of the engine;
the internal excitation of the engine is equivalent to the concentrated load applied to the engine structure, and the position of the concentrated load is determined according to the limitation of test space and test cost.
From the probability density distribution of the engine response, it can be seen that the engine response signal substantially meets the zero-mean gaussian distribution, and therefore, it can be reasonably assumed that the engine internal load is in the form of a zero-mean random load that meets the gaussian distribution.
The space distribution load of the main load source of the engine is equivalent to the concentrated load applied to the engine structure, and the 3 concentrated load positions of the thrust chamber body, the vicinity of the turbine pump and the gas generator body are determined according to the internal load acting position of the engine, the test space and the limit of test cost.
And primarily arranging key component measuring points and load identification measuring points. The critical components place as many stations as possible at the location of interest based on the constraints of component space. The load identification measuring points are required to be arranged near the equivalent excitation points, and complex connection relations such as welding, bolting and the like do not exist between the load identification measuring points and the main transmission path between the excitation points closest to the load identification measuring points. 5 measuring points can be selected near each excitation point, and 15 load identification measuring points can be taken in total. Three-way acceleration sensors can be installed at all measuring point positions.
Specifically, response measurement points are arranged at key components according to test requirements and space position limitations, and load identification measurement points are selected near equivalent excitation points. And measuring transfer functions and coherence functions from the equivalent excitation points to the load identification measuring points and the key component measuring points. And eliminating part of measuring points according to the coherence function, and only reserving 1 measuring point at each key component. And optimizing a sensor layout scheme according to the number of matrix conditions, and finally selecting 1 measuring point near each concentrated load acting point for load identification. The number of the selected measuring points can also be set according to the actual application requirements.
Optionally, removing part of the measuring points according to the coherence function may specifically include:
preliminarily arranging measuring points of key components and load identification measuring points, wherein the key components are arranged at target positions according to the space positions of the components;
the load identification measuring points are arranged near the equivalent excitation points, the main transmission paths between the load identification measuring points and the closest excitation points have no complex connection relations such as welding, bolting and the like, and three-way acceleration sensors are arranged at all measuring point positions.
And (3) applying a frequency response function of a random excitation measurement system by using the vibration exciter, calculating a coherent function of input load and output response, and eliminating part of measuring points according to the coherent function.
In order to reduce the interference of noise and improve the precision of the test measurement transfer function, the maximum energy of a vibration exciter is used for applying random excitation to a structure, and the transfer function and the coherence function from an equivalent excitation point to each load identification measuring point and a key component measuring point are measured, so that the coherence function is ensured to be close to 1 in the whole frequency range as much as possible. In the measurement process, signals need to be windowed and averaged for at least 100 times to eliminate the influence of false excitation and noise pollution. And eliminating part of measuring points according to the coherence function. Considering the safety and cost problems of test run, each key component position only reserves 1 measuring point with the coherence function closest to 1. The precision of the test measurement transfer function has great influence on the load identification result, the correlation function of each load identification measuring point is observed, and if the correlation function is far less than 1 in a large frequency range, the measuring point is removed.
When the number of the external loads of the engine structure is 3, if the external loads of the engine are required to be accurately calculated, the response number is required to be far greater than 3, so that the system dynamics equation is solved in an overdetermined state. However, considering the difficulty in arrangement of test points, 1 point is finally selected at each concentrated load application position, 3 points are added, and 9 sets of response data (x, y and z directions) are measured. The payload is identified using 9 sets of response data.
Optionally, optimizing the sensor layout scheme according to the matrix condition number may specifically include:
based on formula (1)
cond(H)＝||H|| 2 ×||H -1 || 2 (1)
Determining a sensor layout scheme according to a transfer function matrix condition number, wherein I I.I.I.I.A sensor layout scheme is determined according to a transfer function matrix H condition number, wherein I I.I 2 Representing the 2 norms of the matrix, being the maximum singular values of the matrix.
When the optimal sensor layout is selected, assuming that load identification measuring points are not removed, 1 measuring point is selected around the gas generator and around the turbine pump respectively, and 25 combination modes can be adopted. And respectively calculating the condition numbers of the frequency response function matrixes of the 25 combination modes, selecting the combination with the minimum condition number in the whole frequency band, and determining the positions of the load identification measuring point of the gas generator and the load identification measuring point of the turbine pump. On the basis of determining two load identification measuring points, the two load identification measuring points are respectively combined with the load identification measuring points on the thrust chamber in 5 combination modes, the condition number of the transfer function matrix is calculated, the combination with the minimum condition number in the whole frequency band is selected, and the positions of the load identification measuring points of the thrust chamber are determined.
For example, when an engine ground vibration test is carried out, 3 vibration exciters are required to be installed before the engine test is installed and fixed, wherein two 100N vibration exciters are installed near a thrust chamber body part and a turbine pump, and a 10N vibration exciter is installed on a gas generator body part to simulate the phenomena that the thrust chamber and the turbine pump are larger in load and the gas generator is relatively smaller in load in the working process of the engine.
Device commissioning and calibration: after the sensor is installed according to the measuring point arrangement scheme, the data acquisition instrument is opened, and excitation is applied to the engine by using the vibration exciter. And observing whether each sensor has an overscan and a signal is too small, so as to ensure the normal operation of the sensor. The power supply equipment needs to be grounded to reduce 50Hz power supply interference signals, and meanwhile, 50Hz and frequency multiplication signal fluctuation in the signals is noted.
Background noise test: the environmental background noise is required to be tested before the test, the background noise size and the frequency characteristic are analyzed, the test environment is ensured to meet the national standard requirement, and the acquired signal has a high signal-to-noise ratio.
And 3 vibration exciters are simultaneously excited, and the load at each vibration exciter and response data of each measuring point are recorded. The method is used for verifying the applicability of the multi-source load identification method in the problem of multi-source dynamic load identification of the liquid rocket engine.
Optionally, based on the experimental result, identifying the multi-source dynamic load acting on the engine structure by using a regularization method may specifically include:
an inverse model of an engine system is established, a weighting matrix omega is introduced for a dynamic response X containing noise by adopting a formula (2), and an objective function is established:
wherein,,
ω＝diag(ω 1 ,ω 2 ,…,ω m )
h represents a transfer function matrix, m is the number of rows of the transfer function matrix H, n is the number of columns of the transfer function matrix H, X represents the system response, H i,j The j-th element of the ith row of the transfer function matrix H is represented, F represents the identification load, alpha is a regularization parameter, |·|| 2 Representing a matrix 2 norm;
order theThe solution of the objective function is equation (3):
wherein the superscript T represents a matrix transpose;
selecting an optimal regularization parameter by using a GCV method, wherein the GCV function is expressed as a formula (4):
wherein,,i is an identity matrix, trace () represents the trace of the matrix; the minimum point α of the function GCV (α) is the optimal regularization parameter.
The dynamic load of the system is calculated by using the load identification method, the load identification effect is shown in fig. 2, and the measured value of the thrust chamber load is consistent with the calculated value of the thrust chamber load aiming at the load of the thrust chamber, the measured value of the turbine pump load is consistent with the calculated value of the turbine pump load, and the measured value of the gas generator load is consistent with the calculated value of the gas generator load.
The power spectral density function is calculated according to the load amplitude spectrum, the comparison of the power spectral density functions of the identified load and the actually measured load is shown in fig. 3, the PSD of the actual load and the calculated load in the thrust chamber load is basically overlapped, the PSD of the actual load and the calculated load in the turbine pump load is basically overlapped, and the PSD of the actual load and the calculated load in the gas generator load is basically overlapped.
The area enclosed by the power spectrum density function and the coordinate axis is the Root Mean Square (RMS) value of the signal, and the load identification precision is quantitatively analyzed by comparing the actual load with the calculated load RMS value. The thrust chamber measured load RMS was 6.24N, the thrust chamber calculated load RMS was 6.14N, and the error was 1.6%. The turbine pump measured load RMS was 9.18N, the turbine pump calculated load RMS was 9.14N, and the error was 0.44%. The gas generator measured load RMS value was 1.89N, the gas generator calculated load RMS value was 1.86N, and the error was 1.58%. The load identification accuracy is good.
The load identification method is used for calculating the dynamic response of the system by using the load identification and the established dynamic model of the system, and compared with the actual dynamic response, the effect is shown in fig. 4, the response amplitude spectrum of the response measured value and the response calculated value is basically consistent, and the applicability of the load identification method and the accuracy of establishing the dynamic model of the system are further described.
According to the analysis, the multi-source load identification method can accurately identify the load identification problem of the liquid rocket engine. For those skilled in the art, the method is not limited to the problem of load identification of the liquid rocket engine, and has applicability to the problem of load identification of other complex systems.
Based on the same thought, the invention also provides an engine multi-source load identification device, as shown in fig. 5, the device can comprise:
the load equivalent module 510 is configured to equivalent a spatially distributed load of a main load source of the engine to a concentrated load;
a sensor layout optimization module 520 for performing sensor layout optimization of the engine system including the concentrated load based on the coherence function and the frequency response function matrix condition number;
the ground vibration test development module 530 is configured to construct an engine system model based on a sensor layout optimization scheme, and develop an engine ground vibration test to obtain an experimental result;
the multi-source load identification module 540 is configured to identify multi-source dynamic loads acting on the engine structure by using a regularization method based on the experimental result.
Based on the apparatus in fig. 5, some specific implementation units may also be included:
optionally, the apparatus may further include:
the load application position and application mode determining module is used for determining the application position and the application mode of the concentrated load;
an engine system establishment module for establishing an engine system including the concentrated load based on the location of application of the concentrated load and the form of application of the concentrated load.
Optionally, the load applying position and applying manner determining module may specifically include:
the main load source separation unit is used for separating a main load source from the load source of the engine; the main load source comprises a thrust chamber, a turbopump and a gas generator;
the concentrated load form relates to a unit, which is used for analyzing the test response signal, determining the load form born in the working process of the engine according to the response data, and designing and applying the concentrated load form according to the internal load form of the engine;
and the concentrated load position determining unit is used for equivalently applying the internal excitation of the engine as the concentrated load to the engine structure and determining the concentrated load position according to the limitations of the test space and the test cost.
Optionally, the sensor layout optimization module 520 may specifically include:
the response measurement point arrangement unit is used for arranging response measurement points at the key components according to test requirements and space position limitations;
the function determining unit is used for selecting a load identification measuring point near the equivalent excitation point, and measuring transfer functions and coherence functions from the equivalent excitation point to each load identification measuring point and each key component measuring point; removing part of measuring points according to the coherence function, and reserving one measuring point at each key component;
and the sensor layout scheme optimizing unit is used for optimizing the sensor layout scheme according to the number of matrix conditions, and selecting one measuring point near each concentrated load acting point for load identification.
Optionally, the function determining unit may specifically be configured to:
preliminarily arranging measuring points of key components and load identification measuring points, wherein the key components are arranged at target positions according to the space positions of the components;
the load identification measuring points are arranged near the equivalent excitation points, the main transmission paths between the load identification measuring points and the closest excitation points have no complex connection relations such as welding, bolting and the like, and three-way acceleration sensors are arranged at all measuring point positions.
And (3) applying a frequency response function of a random excitation measurement system by using the vibration exciter, calculating a coherent function of input load and output response, and eliminating part of measuring points according to the coherent function.
Optionally, the sensor layout scheme optimizing unit may specifically be configured to:
based on
cond(H)＝||H|| 2 ×||H -1 || 2
According to a transfer function matrixThe condition number determines the sensor layout scheme, the transfer function matrix H condition number, where I 2 Representing the 2 norms of the matrix, being the maximum singular values of the matrix.
Optionally, the multi-source load identification module 540 may specifically include:
the objective function building unit is used for building an inverse model of the engine system, introducing a weighting matrix omega aiming at the dynamic response X containing noise and building an objective function:
ω＝diag(ω 1 ,ω 2 ,…,ω m )
wherein H represents a transfer function matrix, m is the number of rows of the transfer function matrix H, n is the number of columns of the transfer function matrix H, X represents the system response, H i,j The j-th element of the ith row of the transfer function matrix H is represented, F represents the identification load, alpha is a regularization parameter, |·|| 2 Representing a matrix 2 norm;
order theThe solution of the objective function is:
wherein the superscript T represents a matrix transpose;
selecting optimal regularization parameters by using a GCV method, wherein the GCV function is expressed as follows:
wherein,,i is an identity matrix, trace () represents the trace of the matrix; the minimum point α of the function GCV (α) is the optimal regularization parameter.
Based on the same thought, the embodiment of the specification also provides engine multi-source load identification equipment. As shown in fig. 6, the apparatus may include:
the communication unit/communication interface is used for equating the space distribution load of the main load source of the engine into a concentrated load;
a processing unit/processor for performing sensor layout optimization of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number;
constructing an engine system model based on a sensor layout optimization scheme, and developing an engine ground vibration test to obtain an experimental result;
based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
As shown in fig. 6, the terminal device may further include a communication line. The communication line may include a pathway to communicate information between the aforementioned components.
Optionally, as shown in fig. 6, the terminal device may further include a memory. The memory is used for storing computer-executable instructions for executing the scheme of the invention, and the processor is used for controlling the execution. The processor is configured to execute computer-executable instructions stored in the memory, thereby implementing the method provided by the embodiment of the invention.
As shown in fig. 6, the memory may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (random access memory, RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (electrically erasable programmable read-only memory, EEPROM), a compact disc read-only memory (compact disc read-only memory) or other optical disk storage, optical disk storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, without limitation. The memory may be stand alone and be coupled to the processor via a communication line. The memory may also be integrated with the processor.
Alternatively, the computer-executable instructions in the embodiments of the present invention may be referred to as application program codes, which are not particularly limited in the embodiments of the present invention.
In a specific implementation, as one embodiment, as shown in FIG. 6, the processor may include one or more CPUs, such as CPU0 and CPU1 in FIG. 6.
In a specific implementation, as an embodiment, as shown in fig. 6, the terminal device may include a plurality of processors, such as the processor in fig. 6. Each of these processors may be a single-core processor or a multi-core processor.
Based on the same thought, the embodiments of the present disclosure further provide a computer storage medium corresponding to the above embodiments, where instructions are stored, and when the instructions are executed, the method in the above embodiments is implemented.
The above description has been presented mainly in terms of interaction between the modules, and the solution provided by the embodiment of the present invention is described. It is understood that each module, in order to implement the above-mentioned functions, includes a corresponding hardware structure and/or software unit for performing each function. Those of skill in the art will readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The embodiment of the invention can divide the functional modules according to the method example, for example, each functional module can be divided corresponding to each function, or two or more functions can be integrated in one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present invention, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation.
The processor in this specification may also have a function of a memory. The memory is used for storing computer-executable instructions for executing the scheme of the invention, and the processor is used for controlling the execution. The processor is configured to execute computer-executable instructions stored in the memory, thereby implementing the method provided by the embodiment of the invention.
The memory may be, but is not limited to, read-only memory (ROM) or other type of static storage device that can store static information and instructions, random access memory (random access memory, RAM) or other type of dynamic storage device that can store information and instructions, but may also be electrically erasable programmable read-only memory (EEPROM), compact disc-only memory (compact disc read-only memory, CD-ROM) or other optical disk storage, optical disk storage (including compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be stand alone and be coupled to the processor via a communication line. The memory may also be integrated with the processor.
Alternatively, the computer-executable instructions in the embodiments of the present invention may be referred to as application program codes, which are not particularly limited in the embodiments of the present invention.
The method disclosed by the embodiment of the invention can be applied to a processor or realized by the processor. The processor may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The processor may be a general purpose processor, a digital signal processor (digital signal processing, DSP), an ASIC, an off-the-shelf programmable gate array (field-programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be embodied directly in the execution of a hardware decoding processor, or in the execution of a combination of hardware and software modules in a decoding processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.
In a possible implementation manner, a computer readable storage medium is provided, where instructions are stored, and when the instructions are executed, the computer readable storage medium is used to implement the method in the above embodiment.
In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are performed in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a terminal, a user equipment, or other programmable apparatus. The computer program or instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer program or instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center by wired or wireless means. The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that integrates one or more available media. The usable medium may be a magnetic medium, e.g., floppy disk, hard disk, tape; optical media, such as digital video discs (digital video disc, DVD); but also semiconductor media such as solid state disks (solid state drive, SSD).
Although the invention is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Although the invention has been described in connection with specific features and embodiments thereof, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the invention. Accordingly, the specification and drawings are merely exemplary illustrations of the present invention as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (10)
1. A method for identifying engine multisource loads, the method comprising:
the space distribution load of the main load source of the engine is equivalent to the concentrated load;
performing sensor layout optimization of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number;
constructing an engine system model based on a sensor layout optimization scheme, and developing an engine ground vibration test to obtain an experimental result;
based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
2. The method of claim 1, further comprising, prior to optimizing a sensor layout of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number:
determining the application position and the application form of the concentrated load;
an engine system including the concentrated load is built based on the location of application of the concentrated load and the form of application of the concentrated load.
3. The method according to claim 2, wherein determining the location of application of the concentrated load and the form of application of the concentrated load, comprises:
separating a main load source from the load source of the engine; the main load source comprises a thrust chamber, a turbopump and a gas generator;
analyzing the test response signal, determining the load form born in the working process of the engine according to the response data, and designing a concentrated load form according to the internal load form of the engine;
the internal excitation of the engine is equivalent to the concentrated load applied to the engine structure, and the position of the concentrated load is determined according to the limitation of test space and test cost.
4. The method of claim 1, wherein the optimizing the sensor layout of the engine system including the concentrated load is based on a coherence function and a frequency response function matrix condition number, specifically comprising:
arranging response measurement points at key components according to test requirements and space position limitations;
selecting a load identification measuring point near the equivalent excitation point, and measuring transfer functions and coherence functions from the equivalent excitation point to each load identification measuring point and each key component measuring point;
removing part of measuring points according to the coherence function, and reserving one measuring point at each key component;
and optimizing a sensor layout scheme according to the number of matrix conditions, and selecting a measuring point near each concentrated load acting point for load identification.
5. The method according to claim 4, wherein the step of rejecting part of the measurement points according to a coherence function comprises:
preliminarily arranging measuring points of key components and load identification measuring points, wherein the key components are arranged at target positions according to the space positions of the components;
the load identification measuring points are arranged near the equivalent excitation points, and complex connection relations such as welding, bolting and the like do not exist between the load identification measuring points and the main transmission path between the excitation points closest to the load identification measuring points, and three-way acceleration sensors are installed at all measuring point positions;
and (3) applying a frequency response function of a random excitation measurement system by using the vibration exciter, calculating a coherent function of input load and output response, and eliminating part of measuring points according to the coherent function.
6. The method according to claim 4, wherein optimizing the sensor layout scheme according to the matrix condition number, in particular comprises:
based on
cond(H)＝||H|| 2 ×||H -1 || 2
Determining a sensor layout scheme according to a transfer function matrix condition number, wherein I I.I.I.I.A sensor layout scheme is determined according to a transfer function matrix H condition number, wherein I I.I 2 Representing the 2 norms of the matrix asThe largest singular value of the matrix.
7. The method according to claim 1, characterized in that based on the experimental results, a regularization method is used to identify the multi-source dynamic load acting on the engine structure, comprising in particular:
an inverse model of an engine system is established, a weighting matrix omega is introduced for a dynamic response X containing noise, and an objective function is established:
ω＝diag(ω 1 ,ω 2 ,…,ω m )
wherein H represents a transfer function matrix, m is the number of rows of the transfer function matrix H, n is the number of columns of the transfer function matrix H, X represents the system response, H i,j The j-th element of the ith row of the transfer function matrix H is represented, F represents the identification load, alpha is a regularization parameter, |·|| 2 Representing a matrix 2 norm;
order theThe solution of the objective function is:
wherein the superscript T represents a matrix transpose;
selecting optimal regularization parameters by using a GCV method, wherein the GCV function is expressed as follows:
wherein,,i is an identity matrix, trace () represents the trace of the matrix; the minimum point α of the function GCV (α) is the optimal regularization parameter.
8. An engine multisource load recognition device, characterized in that the device comprises:
the load equivalent module is used for equivalent of the space distribution load of the main load source of the engine into concentrated load;
the sensor layout optimization module is used for optimizing the sensor layout of the engine system comprising the concentrated load based on the coherence function and the frequency response function matrix condition number;
the ground vibration test development module is used for constructing an engine system model based on a sensor layout optimization scheme and developing an engine ground vibration test to obtain an experimental result;
and the multi-source load identification module is used for identifying multi-source dynamic loads acting on the engine structure by using a regularization method based on the experimental result.
9. An engine multisource load recognition device, characterized in that the device comprises:
the communication unit/communication interface is used for equating the space distribution load of the main load source of the engine into a concentrated load;
a processing unit/processor for performing sensor layout optimization of an engine system including a concentrated load based on the coherence function and the frequency response function matrix condition number;
constructing an engine system model based on a sensor layout optimization scheme, and developing an engine ground vibration test to obtain an experimental result;
based on the experimental results, a regularization method is utilized to identify multi-source dynamic loads acting on the engine structure.
10. A computer storage medium having instructions stored therein which, when executed, implement the engine multisource load identification method of any one of claims 1 to 7.
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| CN117494476A (en) * | 2023-12-29 | 2024-02-02 | 烟台哈尔滨工程大学研究院 | Measuring point optimization method for improving pneumatic load identification stability of fan tower |
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| CN117494476A (en) * | 2023-12-29 | 2024-02-02 | 烟台哈尔滨工程大学研究院 | Measuring point optimization method for improving pneumatic load identification stability of fan tower |
| CN117494476B (en) * | 2023-12-29 | 2024-04-16 | 烟台哈尔滨工程大学研究院 | Measuring point optimization method for improving pneumatic load identification stability of fan tower |
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