Power assembly excitation force identification method and device

Abstract

The invention relates to a power assembly exciting force identification method and device. The method comprises the steps of obtaining system dynamic stiffness of a power assembly based on multiple hammering modal tests of the power assembly arranged on a fixed rack, obtaining operation centroid acceleration of the power assembly under the steady-state operation condition of the power assembly, and identifying operation excitation force corresponding to the power assembly according to the system dynamic stiffness and the operation centroid acceleration; therefore, based on a fixed test platform (fixed rack) and a modal test technology, the operation excitation force of the power assembly can be identified, an inertia coefficient of the power assembly, parameters of an elastic element and parameters of a damping element do not need to be known, and a supporting counter-supporting force corresponding to the power assembly does not need to be known either, so that the test work is greatly simplified, the test time is shortened, and the test efficiency is improved. The test efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of automobile testing technology, and in particular to a method and device for identifying powertrain excitation force. Background Art

[0002] The powertrain excitation force of commercial vehicles is the main parameter that affects the noise, vibration and harshness (NVH) performance of the whole vehicle, and is the excitation source of the stationary vibration of the whole vehicle. In order to evaluate the performance of each NVH component, it is necessary to quantitatively evaluate the powertrain excitation force of commercial vehicles.

[0003] The powertrain exciting force identification method in the related art needs to measure the inertia parameters of the powertrain, the parameters of the elastic element and the damping element, or the counter-support force, and the test efficiency is low. Summary of the invention

[0004] Based on this, it is necessary to provide a powertrain excitation force identification method and device that can test efficiency in response to the above technical problems.

[0005] In a first aspect, the present application provides a method for identifying a powertrain exciting force, comprising:

[0006] Based on multiple hammer modal tests conducted on the powertrain on a fixed test bench, the system dynamic stiffness of the powertrain is obtained;

[0007] Under the steady-state operating condition of the powertrain, the operating center-of-mass acceleration of the powertrain is obtained;

[0008] According to the system dynamic stiffness and operating center of mass acceleration, the corresponding operating exciting force of the powertrain is identified.

[0009] In one embodiment, the system dynamic stiffness of the powertrain is obtained based on multiple hammer modal tests performed on the powertrain on a fixed bench, including:

[0010] For each hammer modal test, obtain the dynamic stiffness three-axis accelerations corresponding to multiple dynamic stiffness acquisition points corresponding to the hammer modal test and the hammer vector force corresponding to the hammer modal test;

[0011] For each hammer modal test, the dynamic stiffness three-axis acceleration corresponding to multiple dynamic stiffness acquisition points is calculated and processed to obtain the dynamic stiffness center of mass acceleration corresponding to the hammer modal test;

[0012] For each hammer modal test, the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained according to the hammer vector force;

[0013] According to the dynamic stiffness center-of-mass acceleration and dynamic stiffness center-of-mass exciting force corresponding to all hammer modal tests, the system dynamic stiffness of the powertrain is obtained.

[0014] In one embodiment, different hammer modal tests correspond to different hammer collection points, the hammer collection point is one of a plurality of dynamic stiffness collection points, and the number of the hammer collection points is greater than or equal to 9.

[0015] In one embodiment, the dynamic stiffness centroid acceleration corresponding to the hammer modal test is obtained by calculating and processing the dynamic stiffness three-axis acceleration corresponding to the multiple dynamic stiffness acquisition points, including:

[0016] Obtain a first conversion matrix from a crankshaft coordinate system corresponding to the power assembly to a local coordinate system corresponding to each dynamic stiffness collection point, and obtain a first cross product matrix of each dynamic stiffness collection point relative to the center of mass of the power assembly;

[0017] The dynamic stiffness centroid acceleration corresponding to the hammer modal test is obtained by performing calculation processing based on each first conversion matrix, each first cross product matrix and each dynamic stiffness three-way acceleration.

[0018] In one embodiment, the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained according to the hammer vector force, including:

[0019] The dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained by performing calculations based on the first cross product matrix, the first conversion matrix and the vector force.

[0020] In one embodiment, obtaining the running center of mass acceleration of the powertrain under the steady-state running condition of the powertrain includes:

[0021] For each running collection point, obtain a second cross product matrix of the running collection point relative to the center of mass of the powertrain, and obtain a second conversion matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to the running collection point;

[0022] Obtaining the three-dimensional acceleration of each running collection point when the powertrain is in steady-state operation;

[0023] The operating center of mass acceleration of the powertrain is obtained according to the operating three-dimensional accelerations of all operating collection points, the second cross product matrix and the second conversion matrix.

[0024] In one of the embodiments, the modal frequency of the operating acquisition point is greater than a preset frequency value.

[0025] In one of the embodiments, the number of running collection points is greater than or equal to 4.

[0026] In one of the embodiments, the number of the running collection points is equal to 4, and the distance between two adjacent running collection points is greater than a preset distance threshold.

[0027] In a second aspect, the present application further provides a powertrain exciting force identification device, comprising:

[0028] A system dynamic stiffness acquisition module, used to acquire the system dynamic stiffness of the powertrain based on multiple hammer modal tests performed on the powertrain on a fixed bench;

[0029] A mass center acceleration acquisition module is used to acquire the operation mass center acceleration of the powertrain under the steady-state operation condition of the powertrain;

[0030] The exciting force identification module is used to identify the operating exciting force corresponding to the powertrain according to the system dynamic stiffness and the operating center of mass acceleration.

[0031] The above-mentioned powertrain exciting force identification method and device obtain the system dynamic stiffness of the powertrain through multiple hammer modal tests based on the powertrain set on a fixed test bench, obtain the operating center of mass acceleration of the powertrain under the steady-state operation condition of the powertrain, and identify the operating exciting force corresponding to the powertrain based on the system dynamic stiffness and the operating center of mass acceleration; in this way, based on the fixed test platform (fixed test bench) and modal testing technology, the operating exciting force of the powertrain can be identified without knowing the inertia coefficient, elastic element parameters and damping element parameters of the powertrain, nor the corresponding support and reaction force of the powertrain, which greatly simplifies the testing work, shortens the testing time and improves the testing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] FIG1 is a diagram showing an application environment of a method for identifying powertrain excitation force in one embodiment;

[0034] Figure 2 is a schematic flow chart of a method for identifying exciting force of a powertrain in one embodiment;

[0035] Figure 3 A schematic diagram of a process for obtaining the system dynamic stiffness of a powertrain in one embodiment;

[0036] Figure 4 is an exemplary schematic diagram of a powertrain geometric model in one embodiment;

[0037] Figure 5 It is a schematic diagram of a process of obtaining the running center of mass acceleration of a power assembly in one embodiment;

[0038] Figure 6 1 is a structural block diagram of a powertrain exciting force identification device in one embodiment. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] The powertrain excitation force identification method provided in the embodiment of the present application can be applied in the application environment shown in Figure 1. As shown in Figure 1, during the excitation force identification process, the powertrain is fixedly set on a fixed stand, and the test equipment is connected to the powertrain to perform a hammer modal test on the powertrain and obtain relevant test data.

[0041] The powertrain, or powerplant in English, refers to a series of components that generate power on a vehicle and transmit it to the road. In a broad sense, it includes the engine, gearbox, drive shaft, differential, clutch, etc. In some embodiments, the powertrain includes the engine, gearbox, and other parts integrated into the gearbox, such as clutch / front differential, etc.

[0042] The test equipment includes a vibration device, an acceleration sensor, a data acquisition system, a signal processing software and other auxiliary equipment; among which, the vibration device may include a vibration hammer, and the auxiliary equipment may include a hammer response hammer calibrator, a vibration analyzer, etc.

[0043] In an exemplary embodiment, please refer to Figure 2 , a powertrain excitation force identification method is provided, which can be used in the test device in FIG1 , and in other embodiments, the powertrain excitation force identification method can also be used in other computer devices connected to the test device. Figure 2 As shown, the method includes:

[0044] Step 202 : obtaining the system dynamic stiffness of the powertrain based on multiple hammer modal tests performed on the powertrain on a fixed test bench.

[0045] Among them, hammer modal testing refers to a testing method that stimulates the vibration response of the object under test by applying impact force to it, thereby evaluating its dynamic characteristics.

[0046] Among them, dynamic stiffness refers to the ability of an object or structure to resist deformation under dynamic loads (forces that change with time), and is an important parameter that describes the rigidity characteristics of an object or structure under vibration or dynamic conditions. Among them, dynamic stiffness changes with frequency and is a frequency-related parameter. For each modal frequency, the dynamic stiffness will change significantly. In the frequency range far from the natural frequency, the dynamic stiffness is usually higher and the structure responds less to dynamic forces. Damping will affect the dynamic sensitivity of the system. Generally, the greater the damping, the higher the dynamic stiffness of the system. In modal analysis, each modal frequency corresponds to a modal shape and corresponding dynamic stiffness.

[0047] Exemplarily, the powertrain is first fixed on a fixed platform, a plurality of dynamic stiffness collection points are determined on the powertrain, a three-axis acceleration sensor is arranged at a position corresponding to each dynamic stiffness collection point, an impact force is applied to multiple positions of the powertrain using a force hammer, and the three-axis acceleration of each dynamic stiffness collection point is obtained according to the three-axis acceleration sensor arranged at the collection point of each dynamic stiffness collection point. The aforementioned three-axis accelerations are converted into the frequency domain to obtain the frequency response function corresponding to each dynamic stiffness collection point, and the system dynamic stiffness of the powertrain is calculated in combination with the magnitude of the applied impact force.

[0048] Among them, the system dynamic stiffness refers to the dynamic stiffness characteristics corresponding to the center of mass position of the powertrain, which is used to characterize the dynamic stiffness characteristics of the powertrain as a whole, and to characterize information such as the mass, dynamic stiffness and damping characteristics of the powertrain.

[0049] After the powertrain is set on a fixed stand, the crankshaft coordinate system corresponding to the powertrain is determined. , further determine the center of mass coordinates of the powertrain in the crankshaft coordinate system .

[0050] Step 204 : Under the steady-state operating condition of the powertrain, obtain the operating center of mass acceleration of the powertrain.

[0051] Among them, the steady-state operating condition of the powertrain refers to the main operating parameters of the powertrain, such as speed, torque, etc., which remain relatively stable without obvious fluctuations or changes.

[0052] Exemplarily, the engine is started, and after the engine runs stably, the engine speed is fixed at a desired speed.

[0053] Among them, the operating center of mass acceleration of the powertrain refers to the three-dimensional acceleration corresponding to the center of mass position of the powertrain under steady-state operating conditions.

[0054] For example, in the crankshaft coordinate system, the center of mass acceleration of the powertrain is Can be represented as a six-dimensional data ,in, , and are the linear acceleration of the center of mass of the powertrain in three-dimensional space, , and are the angular accelerations of the center of mass of the powertrain in three-dimensional space.

[0055] The three-dimensional acceleration of a certain sampling point m on the powertrain in the local coordinate system corresponding to the sampling point m The relationship with the center of mass acceleration of the powertrain is: ,in, Refers to the coordinate system transformation matrix between the local coordinate system corresponding to the acquisition point m and the crankshaft coordinate system, It refers to the cross product matrix between the coordinate data of the collection point m relative to the centroid, and E is the unit matrix.

[0056] In this way, under the steady-state operation condition of the powertrain, the operating center of mass acceleration of the powertrain is calculated by acquiring the three-dimensional acceleration data of multiple acquisition points.

[0057] Step 206 : Identify the operating exciting force corresponding to the powertrain according to the system dynamic stiffness and the operating center of mass acceleration.

[0058] The operating exciting force corresponding to the powertrain can be expressed by the exciting force corresponding to the center of mass position of the powertrain.

[0059] Exemplarily, the operating exciting force corresponding to the powertrain can be obtained according to the following formula:

[0060] ,

[0061] in, It represents the running excitation force of the powertrain and is a six-dimensional data, where: , and Refers to the amplitude of the exciting force in three-dimensional space. , and Refers to the moment of the exciting force in three-dimensional space; K represents the dynamic stiffness of the system, Indicates the running center of mass acceleration.

[0062] The powertrain exciting force identification method provided above obtains the system dynamic stiffness of the powertrain through multiple hammer modal tests based on the powertrain set on a fixed test bench, obtains the operating center of mass acceleration of the powertrain under steady-state operating conditions, and identifies the operating exciting force corresponding to the powertrain based on the system dynamic stiffness and the operating center of mass acceleration; in this way, based on a fixed test platform (fixed test bench) and modal testing technology, the operating exciting force of the powertrain can be identified without knowing the inertia coefficient, elastic element parameters and damping element parameters of the powertrain, nor the corresponding support and reaction force of the powertrain, which greatly simplifies the testing work, shortens the testing time and improves the testing efficiency.

[0063] In an exemplary embodiment, based on Figure 2 For the implementation shown, please refer to Figure 3 The powertrain excitation force identification method provided in the present invention involves the process of how to conduct multiple hammer modal tests on the powertrain on a fixed test bench to obtain the system dynamic stiffness of the powertrain. Figure 3 As shown, the process includes steps 302 to 308, wherein:

[0064] Step 302, for each hammer modal test, obtain the dynamic stiffness three-axis accelerations corresponding to a plurality of dynamic stiffness acquisition points corresponding to the hammer modal test and the hammer vector force corresponding to the hammer modal test.

[0065] Exemplarily, M dynamic stiffness collection points are set at the rigid part of the powertrain surface, and a three-dimensional acceleration sensor is arranged at each dynamic stiffness collection point to collect the dynamic stiffness three-dimensional acceleration corresponding to each dynamic stiffness collection point during the hammer modal test. Using the modal test equipment and a force hammer, N different dynamic stiffness collection points are found as hammer collection points on the M dynamic stiffness collection points to perform hammer modal tests respectively; for each hammer modal test, the hammer vector force corresponding to the hammer modal test is obtained. The dynamic stiffness three-axis acceleration corresponding to the M dynamic stiffness collection points , where n=1,2,...,N, refers to the nth impact modal test, Store the collection point serial number information j, , including the acceleration in the local coordinate system of M dynamic stiffness acquisition points; ,in and Hammer collection points The hammer vector force Relative to the hammer point The unit vector and magnitude of the local coordinate system of .

[0066] Optionally, in each hammer modal test, multiple hammer vector forces can be applied to the hammer collection point, and the dynamic stiffness three-axis acceleration and hammer vector force corresponding to each hammer vector force are averaged as the dynamic stiffness three-axis acceleration and hammer vector force of the hammer modal test corresponding to the hammer collection point, so as to determine the subsequent dynamic stiffness center of mass acceleration and dynamic stiffness center of mass exciting force.

[0067] It should be noted that the dynamic stiffness three-axis acceleration or the running three-axis acceleration or other types of acceleration in the embodiments of the present application are acceleration spectrum data obtained by converting the time domain acceleration data obtained by the sensor into the frequency domain through Fourier transform.

[0068] Step 304, for each hammer modal test, the dynamic stiffness three-axis acceleration corresponding to the multiple dynamic stiffness acquisition points is calculated and processed to obtain the dynamic stiffness center of mass acceleration corresponding to the hammer modal test.

[0069] In a possible implementation, step 304 includes: obtaining a first transformation matrix from a crankshaft coordinate system corresponding to the powertrain to a local coordinate system corresponding to each dynamic stiffness collection point, obtaining a first cross product matrix of each dynamic stiffness collection point relative to the center of mass of the powertrain, and performing calculations based on each first transformation matrix, each first cross product matrix, and each dynamic stiffness three-way acceleration to obtain the dynamic stiffness center of mass acceleration corresponding to the hammer modal test.

[0070] Among them, determine the coordinates of each dynamic stiffness collection point i in the crankshaft coordinate system , where i ranges from 1 to M. Exemplarily, the coordinate data of the center of mass of the powertrain in the crankshaft coordinate system is (mm), the number of dynamic stiffness collection points is 27, and the position data of each dynamic stiffness collection point in the crankshaft coordinate system is shown in Table 1. Among them, the FullName in Table 1 corresponds to each dynamic stiffness collection point shown in Figure 1, X (m), Y (m) and Z (m) refer to the position data of the corresponding dynamic stiffness collection point in the crankshaft coordinate system, where m is the distance unit meter; XY (°), XZ (°) and YZ (°) refer to the relative offset angles of the three axes between the local coordinate system corresponding to the corresponding dynamic stiffness collection point and the crankshaft coordinate system. In this example, the relative offset angles are all 0. It can be understood that in other examples, the relative offset angle may not be 0.

[0071] Table 1 Example of location data of dynamic stiffness collection points

[0072]

[0073] At the dynamic stiffness collection point, according to the surface shape of the powertrain, the powertrain geometric model is established, and a local coordinate system is established for each dynamic stiffness collection point i Please refer to Figure 4 , is an exemplary schematic diagram of a powertrain geometric model, and each dynamic stiffness collection point establishes a local coordinate system. Determine the crankshaft coordinate system To each local coordinate system The rotation transformation matrix In this embodiment, the rotation transformation matrix from the crankshaft coordinate system to the local coordinate system corresponding to the dynamic stiffness collection point is called the first transformation matrix to distinguish the rotation transformation matrix from the crankshaft coordinate system to the local coordinate system corresponding to the running collection point in subsequent embodiments.

[0074] According to the dynamic stiffness, the coordinate difference data of point i relative to the center of mass is collected , determine the cross product matrix of the dynamic stiffness collection point i , wherein the cross product matrix of the dynamic stiffness collection points in this embodiment is called the first cross product matrix to distinguish the cross product matrices corresponding to the running collection points in subsequent embodiments.

[0075] Among them, the acceleration of the local coordinate system of the dynamic stiffness acquisition point i is , and the acceleration in the crankshaft coordinate system The relationship is: The dynamic stiffness three-axis acceleration in the local coordinate system of the dynamic stiffness acquisition point i in the crankshaft coordinate system is Dynamic stiffness and center-of-mass acceleration corresponding to the powertrain The relationship is: ; Among them, the dynamic stiffness three-axis acceleration corresponding to all dynamic stiffness collection points and the dynamic stiffness center of mass acceleration The relationship is: ;in, Refers to the dynamic stiffness center-of-mass acceleration obtained from the nth impact modal test.

[0076] Among them, Recorded as acceleration conversion matrix , then the dynamic stiffness center-of-mass acceleration that can be obtained from the nth hammer modal test is ; The + symbol in the upper right corner of the matrix represents the Moore-Penrose generalized inverse.

[0077] Step 306, for each hammer modal test, obtain the dynamic stiffness center of mass exciting force corresponding to the hammer modal test according to the hammer vector force.

[0078] In a possible implementation, step 306 further includes: obtaining a first cross product matrix of the hammer collection point corresponding to the hammer modal test relative to the center of mass of the powertrain, and obtaining a first transformation matrix between the local coordinate system corresponding to the hammer collection point and the crankshaft coordinate system corresponding to the powertrain; performing calculations based on the first cross product matrix, the first transformation matrix and the vector force to obtain the dynamic stiffness center of mass excitation force corresponding to the hammer modal test.

[0079] Among them, the dynamic stiffness center of mass exciting force obtained from the nth hammer modal test is .in, The hammer collection point corresponding to the nth hammer modal test The hammer vector force conversion matrix.

[0080] Step 308 , obtaining the system dynamic stiffness of the powertrain according to the dynamic stiffness center-of-mass acceleration and the dynamic stiffness center-of-mass exciting force corresponding to all the hammer modal tests.

[0081] Among them, the dynamic stiffness center-of-mass acceleration and the dynamic stiffness center-of-mass exciting force at the center of mass have the following relationship: ; Where: K represents the system dynamic stiffness matrix of dimension 6*6, which contains information such as system mass, dynamic stiffness and damping. Further, In this way, according to the dynamic stiffness center-of-mass acceleration and dynamic stiffness center-of-mass exciting force corresponding to all hammer modal tests, the process of obtaining the system dynamic stiffness of the powertrain can be expressed by the following formula: .

[0082] In an exemplary embodiment, different hammer modal tests correspond to different hammer collection points, the hammer collection point is one of a plurality of dynamic stiffness collection points, and the number of the hammer collection points is greater than or equal to 9.

[0083] The number of hammering collection points is less than or equal to the number of stiffness collection points.

[0084] Optionally, the number of dynamic stiffness collection points is greater than or equal to 12, and the plurality of dynamic stiffness collection points can display geometric features of the powertrain. Exemplarily, the number of dynamic stiffness collection points is 27.

[0085] Optionally, the number of hammer collection points is equal to 9, and the up-down direction, left-right direction, and front-back direction of the powertrain each include at least one hammer collection point.

[0086] In an exemplary embodiment, based on Figure 2 For the examples shown, please refer to Figure 5 This embodiment relates to the process of obtaining the center of mass acceleration of the powertrain under steady-state operation of the powertrain. Figure 5As shown, the process includes steps 502 to 506.

[0087] Step 502 : for each operation collection point, obtain a second cross product matrix of the operation collection point relative to the center of mass of the powertrain, and obtain a second conversion matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to the operation collection point.

[0088] The operation collection point may be one or more of the dynamic stiffness collection points, or may be different from the dynamic stiffness collection points.

[0089] In a possible implementation, in the process of obtaining the center of mass acceleration of the powertrain, an operation collection point different from the dynamic stiffness collection point is reset, and an acceleration sensor is arranged at the operation collection point position to collect the operation three-dimensional acceleration corresponding to each operation collection point position when the powertrain is in steady state operation. Among them, the "operation" in the operation three-dimensional acceleration is only used to limit the correspondence between the three-dimensional acceleration data and the operation collection point, which is obtained when the powertrain is in steady state operation, and does not limit the form and content of the three-dimensional acceleration data. For example, the data form of the operation three-dimensional acceleration and the dynamic stiffness three-dimensional acceleration is consistent.

[0090] Optionally, the modal frequency corresponding to the running collection point is greater than a preset frequency value. Exemplarily, the preset frequency value is 400 Hz. That is, in this embodiment, a position with greater rigidity on the surface of the powertrain is selected as the running collection point.

[0091] Optionally, the number of the running collection points is greater than or equal to 4. Exemplarily, the number of the running collection points is equal to 4, and the distance between any two running collection points is greater than a preset distance threshold.

[0092] Exemplarily, the position data of each running acquisition point in the crankshaft coordinate system is shown in Table 2. Among them, X (mm), Y (mm) and Z (mm) in Table 2 refer to the position data of the corresponding running acquisition point in the crankshaft coordinate system, wherein the distance unit of mm is millimeter, and XY (°), XZ (°) and YZ (°) refer to the relative offset angles of the three axes between the local coordinate system corresponding to the corresponding running acquisition point and the crankshaft coordinate system. In this example, the relative offset angles are all 0. It can be understood that in other examples, the relative offset angle may not be 0.

[0093] Table 2, example of location data of running collection points

[0094]

[0095] Among them, the second cross product matrix corresponding to the running collection point k The determination method of is similar to the determination method of the first cross product matrix. The second transformation matrix corresponding to the running acquisition point k is The method for determining is similar to the method for determining the first conversion matrix, and will not be repeated here.

[0096] Step 504 , obtaining the three-axis acceleration of each operation collection point when the powertrain is in steady-state operation.

[0097] Among them, under the steady-state operation condition of the powertrain, the time domain acceleration data of each operation collection point is obtained by arranging the acceleration sensors at the operation collection points, and the Fourier transform is performed to obtain the three-dimensional acceleration of each operation collection point in the frequency domain.

[0098] Step 506 , obtaining the running center of mass acceleration of the powertrain according to the running three-dimensional accelerations of all running collection points, the second cross product matrix and the second conversion matrix.

[0099] For example, the powertrain's operating center of mass acceleration ; Where Z is the number of running collection points.

[0100] In an exemplary embodiment, a method for identifying a powertrain excitation force is provided, which can be used in the test device in FIG1 . The method includes:

[0101] Step S2, when the powertrain is set on a fixed platform, obtain a first transformation matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to each dynamic stiffness collection point, and obtain a first cross product matrix of each dynamic stiffness collection point relative to the center of mass of the powertrain.

[0102] Step S4, for each hammer modal test, obtain the dynamic stiffness three-axis accelerations corresponding to multiple dynamic stiffness acquisition points corresponding to the hammer modal test and the hammer vector force corresponding to the hammer modal test.

[0103] Optionally, different hammer modal tests correspond to different hammer collection points, the hammer collection point is one of multiple dynamic stiffness collection points, and the number of hammer collection points is greater than or equal to 9.

[0104] Step S6, for each hammer modal test, calculation and processing are performed according to each first conversion matrix, each first cross product matrix and each dynamic stiffness three-dimensional acceleration to obtain the dynamic stiffness center of mass acceleration corresponding to the hammer modal test.

[0105] Step S8, for each hammer modal test, calculation and processing are performed according to the first cross product matrix, the first conversion matrix and the vector force to obtain the dynamic stiffness center of mass exciting force corresponding to the hammer modal test.

[0106] Step S10, obtaining the system dynamic stiffness of the powertrain according to the dynamic stiffness center-of-mass acceleration and the dynamic stiffness center-of-mass exciting force corresponding to all hammer modal tests.

[0107] Step S12, under the steady-state operation condition of the powertrain, for each operation collection point, obtain a second cross product matrix of the operation collection point relative to the center of mass of the powertrain, and obtain a second conversion matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to the operation collection point;

[0108] Step S14, obtaining the three-axis acceleration of each operation collection point when the powertrain is in steady-state operation.

[0109] Step S16, obtaining the running center of mass acceleration of the powertrain according to the running three-dimensional accelerations of all running collection points, the second cross product matrix and the second conversion matrix.

[0110] Step S18, identifying the operating exciting force corresponding to the powertrain according to the system dynamic stiffness and the operating center of mass acceleration.

[0111] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0112] It is understood that the term "based on" used in this application is used to describe one or more factors that affect the determination, and does not exclude other factors that may affect the determination. For example, the phrase "determine A based on B" means that the determination of A can be based entirely or at least partially on factor B, that is, B is a factor that affects the determination of A, but does not exclude that the determination of A is also based on C.

[0113] Based on the same inventive concept, the embodiment of the present application also provides a powertrain excitation force identification device for implementing the powertrain excitation force identification method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations of one or more powertrain excitation force identification device embodiments provided below can refer to the limitations of the powertrain excitation force identification method above, and will not be repeated here.

[0114] In an exemplary embodiment, please refer to Figure 6, a powertrain exciting force identification device is provided, comprising: a system dynamic stiffness acquisition module 602, a center of mass acceleration acquisition module 604 and an exciting force identification module 606, wherein:

[0115] A system dynamic stiffness acquisition module 602, for acquiring the system dynamic stiffness of the powertrain based on multiple hammer modal tests performed on the powertrain on a fixed bench;

[0116] The mass center acceleration acquisition module 604 is used to acquire the operation mass center acceleration of the powertrain under the steady-state operation condition of the powertrain;

[0117] The exciting force identification module 606 is used to identify the operating exciting force corresponding to the powertrain according to the system dynamic stiffness and the operating center of mass acceleration.

[0118] In an exemplary embodiment, the system dynamic stiffness acquisition module 602 is used to obtain, for each hammer modal test, the dynamic stiffness three-dimensional accelerations corresponding to the multiple dynamic stiffness acquisition points corresponding to the hammer modal test and the hammer vector force corresponding to the hammer modal test; for each hammer modal test, the dynamic stiffness center-of-mass acceleration corresponding to the hammer modal test is calculated and processed according to the dynamic stiffness three-dimensional accelerations corresponding to the multiple dynamic stiffness acquisition points; for each hammer modal test, the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained according to the hammer vector force; according to the dynamic stiffness center-of-mass acceleration and the dynamic stiffness center-of-mass exciting force corresponding to all hammer modal tests, the system dynamic stiffness of the powertrain is obtained.

[0119] In an exemplary embodiment, different hammer modal tests correspond to different hammer collection points, the hammer collection point is one of a plurality of dynamic stiffness collection points, and the number of the hammer collection points is greater than or equal to 9.

[0120] In an exemplary embodiment, the system dynamic stiffness acquisition module 602 is used to obtain the first transformation matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to each dynamic stiffness collection point, and obtain the first cross product matrix of each dynamic stiffness collection point relative to the center of mass of the powertrain; calculation and processing are performed based on each first transformation matrix, each first cross product matrix and each dynamic stiffness three-way acceleration to obtain the dynamic stiffness center of mass acceleration corresponding to the hammer modal test.

[0121] In an exemplary embodiment, the system dynamic stiffness acquisition module 602 is used to perform calculations based on the first cross product matrix, the first conversion matrix and the vector force to obtain the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test.

[0122] In an exemplary embodiment, the center of mass acceleration acquisition module 604 is used to obtain, for each operation collection point, a second cross product matrix of the operation collection point relative to the center of mass of the powertrain, and obtain a second transformation matrix from the crankshaft coordinate system corresponding to the powertrain to the local coordinate system corresponding to the operation collection point; obtain the three-dimensional operation acceleration of each operation collection point when the powertrain is in steady-state operation; and obtain the operation center of mass acceleration of the powertrain based on the three-dimensional operation acceleration of all operation collection points, the second cross product matrix, and the second transformation matrix.

[0123] In an exemplary embodiment, the modal frequency of the operating acquisition point is greater than a preset frequency value.

[0124] In an exemplary embodiment, the number of running collection points is greater than or equal to 4.

[0125] In an exemplary embodiment, the number of the running collection points is equal to 4, and the distance between two adjacent running collection points is greater than a preset distance threshold.

[0126] Each module in the above-mentioned powertrain exciting force identification device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0127] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program. Exemplarily, the computer device is the test device shown in FIG1 .

[0128] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0129] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0130] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0131] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0132] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for identifying powertrain excitation force, characterized in that: The method comprises: Based on multiple hammer modal tests performed on the power assembly on a fixed bench, obtaining the system dynamic stiffness of the power assembly; Under the steady-state operating condition of the power assembly, obtaining the operating center of mass acceleration of the power assembly; An operating exciting force corresponding to the powertrain is identified according to the system dynamic stiffness and the operating center of mass acceleration.

2. The method according to claim 1, characterized in that The obtaining of the system dynamic stiffness of the power assembly based on multiple hammer modal tests performed on the fixed bench comprises: For each of the hammer modal tests, obtain the dynamic stiffness three-axis accelerations respectively corresponding to a plurality of dynamic stiffness acquisition points corresponding to the hammer modal test and the hammer vector force corresponding to the hammer modal test; For each of the hammer modal tests, the dynamic stiffness three-axis accelerations corresponding to the multiple dynamic stiffness acquisition points are calculated and processed to obtain the dynamic stiffness centroid acceleration corresponding to the hammer modal test; For each of the hammer modal tests, the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained according to the hammer vector force; The system dynamic stiffness of the power assembly is obtained according to the dynamic stiffness center-of-mass acceleration and the dynamic stiffness center-of-mass exciting force respectively corresponding to all the hammer modal tests.

3. The method according to claim 2, characterized in that Different hammer modal tests correspond to different hammer collection points, and the hammer collection point is one of the multiple dynamic stiffness collection points. The number of the hammer collection points is greater than or equal to 9.

4. The method according to claim 2, characterized in that: The calculating and processing of the three-dimensional accelerations of the dynamic stiffness corresponding to the multiple dynamic stiffness acquisition points to obtain the dynamic stiffness centroid acceleration corresponding to the hammer modal test includes: Obtaining a first conversion matrix from a crankshaft coordinate system corresponding to the power assembly to a local coordinate system corresponding to each of the dynamic stiffness collection points, and obtaining a first cross product matrix of each of the dynamic stiffness collection points relative to the center of mass of the power assembly; The dynamic stiffness center-of-mass acceleration corresponding to the hammer modal test is obtained by performing calculation processing based on each of the first conversion matrices, each of the first cross product matrices, and each of the three-dimensional accelerations of the dynamic stiffness.

5. The method according to claim 4, characterized in that According to the hammer vector force, the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test is obtained, including: Calculation is performed based on the first cross product matrix, the first conversion matrix and the vector force to obtain the dynamic stiffness center-of-mass exciting force corresponding to the hammer modal test.

6. The method according to claim 1, characterized in that The step of obtaining the operating center of mass acceleration of the powertrain under the steady-state operating condition of the powertrain includes: For each operation collection point, a second cross product matrix of the operation collection point relative to the center of mass of the power assembly is obtained, and a second conversion matrix from a crankshaft coordinate system corresponding to the power assembly to a local coordinate system corresponding to the operation collection point is obtained; Acquiring the three-dimensional acceleration of each of the operation collection points when the powertrain is in steady-state operation; The operating center-of-mass acceleration of the powertrain is obtained according to the operating three-dimensional accelerations of all the operating collection points, the second cross product matrix and the second conversion matrix.

7. The method according to claim 6, characterized in that The modal frequency of the operation acquisition point is greater than a preset frequency value.

8. The method according to claim 6, characterized in that The number of the running collection points is greater than or equal to 4.

9. The method according to claim 8, characterized in that The number of the running collection points is equal to 4, and the distance between two adjacent running collection points is greater than a preset distance threshold.

10. A powertrain excitation force identification device, characterized in that: The powertrain exciting force identification device comprises: A system dynamic stiffness acquisition module, used to acquire the system dynamic stiffness of the power assembly based on multiple hammer modal tests performed on the power assembly on a fixed bench; A mass center acceleration acquisition module, used to acquire the operation mass center acceleration of the power assembly under the steady-state operation condition of the power assembly; The exciting force identification module is used to identify the operating exciting force corresponding to the powertrain according to the system dynamic stiffness and the operating center of mass acceleration.

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