Frame structure assembling and testing method and system of electro-tricycle

Abstract

The invention discloses a frame structure assembling and testing method and system of an electro-tricycle, and relates to the related field of frame testing, and the method comprises the steps: obtaining M frame structures of a to-be-tested frame, and assembling N assembling connection points of the M frame structures; carrying out connection performance analysis on the connection points, and generating performance parameters of N connection points; m frame design parameters are collected, and resonance tests between a frame and a road surface, between frame structures and between the frame and other tricycle structures are carried out under various driving working conditions; performing vibration cycle damage analysis on the N assembly connection points according to the first resonance test result, the second resonance test result, the third resonance test result and the performance parameters of the N connection points, and positioning assembly defect nodes; and generating a frame structure assembly test result according to the assembly defect nodes. The technical problem that the test precision is difficult to guarantee in the assembly test of the frame structure of the existing electro-tricycle is solved, and the technical effect of improving the test precision is achieved.

Description

Technical Field

[0001] The present application relates to the field of frame testing, and in particular to a frame structure assembly testing method and system for an electric tricycle. Background Art

[0002] As the core component of electric tricycles, the structural design and assembly quality of the frame are directly related to the safety, stability and service life of the vehicle. In the existing electric tricycle frame structure assembly test, a certain static load is usually applied to the frame to observe the deformation and stress distribution of the frame. This method can reflect the load-bearing capacity of the frame under static conditions, but it cannot simulate the dynamic working conditions in actual driving. Due to the singleness of the test conditions, the comprehensiveness and accuracy of the test are insufficient.

[0003] In the current related technologies, there is a technical problem in the frame structure assembly test of electric tricycles that the test accuracy is difficult to ensure. Summary of the invention

[0004] The present application provides a frame structure assembly test method and system for an electric tricycle, which obtains M frame structures and N assembly connection points of the frame to be tested, performs connection performance analysis on the connection points, collects frame design parameters and performs resonance tests under various driving conditions, performs vibration cycle damage analysis based on the resonance test results and connection point performance parameters, locates assembly defect nodes and other technical means, and accurately reflects the performance of the frame under various driving conditions through resonance testing and vibration cycle damage analysis, thereby achieving the technical effect of improving test accuracy.

[0005] The present application provides a frame structure assembly test method for an electric tricycle, comprising: obtaining M frame structures of a frame to be tested, and assembling N assembly connection points of the M frame structures, wherein M and N are integers greater than or equal to 1; performing connection performance analysis on the N assembly connection points to generate N connection point performance parameters; collecting M frame design parameters of the M frame structures, performing resonance tests between the frame and a road surface, between frame structures, and between the frame and other tricycle structures under a variety of driving conditions, respectively, to generate a first resonance test result, a second resonance test result, and a third resonance test result; performing vibration cycle damage analysis on the N assembly connection points using the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters to locate assembly defect nodes; and generating a frame structure assembly test result using the assembly defect nodes.

[0006] In a possible implementation, M frame design parameters of the M frame structures are collected, and resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures are respectively performed under multiple driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result, and the following processing is performed: configuration of the road surface state and driving parameters is performed to establish the multiple driving conditions; the overall natural frequency of the frame and the natural frequencies of the M frame structures are fitted based on the M frame design parameters; the natural frequencies of other tricycle structures are determined; the relationship between the road surface excitation frequency and the overall natural frequency of the frame is tested under the multiple driving conditions to generate the first resonance test result; the vibration excitation relationship between any adjacent frame structures is tested under the multiple driving conditions, and a resonance analysis between the frame structures is performed in combination with the natural frequencies of the M frame structures to generate the second resonance test result; the vibration excitation relationship between the frame and other tricycle structures is tested under the multiple driving conditions, and a resonance analysis between the frame structures is performed in combination with the overall natural frequency of the frame and the natural frequencies of the other tricycle structures to generate the third resonance test result.

[0007] In a possible implementation, the configuration of the road surface state and driving parameters is performed, the multiple driving conditions are established, and the following processing is performed: determine the matching electric tricycle of the frame to be tested, and collect the factory-recommended road environment constraints; based on the factory-recommended road environment constraints, collect various road surface flatness parameters; collect the driving speed constraints of the matching electric tricycle; construct various driving test parameters based on the driving speed constraints, wherein the various driving test parameters at least include parameters of the matching electric tricycle under uniform speed, acceleration, deceleration, sudden braking and turning conditions; extract one parameter from each of the road surface flatness parameters and each of the driving test parameters, combine them, and generate the multiple driving conditions.

[0008] In a possible implementation, the relationship between the road excitation frequency and the overall natural frequency of the frame is tested under the multiple driving conditions to generate the first resonance test result, and the following processing is performed: the frame to be tested is virtually assembled with other tricycle structures, and vibration modeling data under actual working conditions is collected for digital twin modeling to establish a twin tricycle operation simulation model; the multiple driving conditions are simulated with the twin tricycle operation simulation model to record multiple road excitation frequencies; the influence of the multiple road excitation frequencies on the overall natural frequency of the frame is analyzed to generate the first resonance test result.

[0009] In a possible implementation, the vibration excitation relationship between any adjacent frame structures is tested under the multiple driving conditions, and a resonance analysis between the frame structures is performed in combination with the natural frequencies of the M frame structures to generate the second resonance test result, and the following processing is performed: determining the adjacent first frame structure and the second frame structure; collecting the connection characteristics of the assembly connection points between the first frame structure and the second frame structure, wherein the connection characteristics include the connection mode and the contact area; performing a vibration coupling analysis based on the connection characteristics of the assembly connection points to generate a first vibration coupling relationship; optimizing the twin tricycle operation simulation model with the first vibration coupling relationship, simulating the multiple driving conditions with the optimized simulation model, recording the vibration frequencies corresponding to the M frame structures respectively, and comparing them with the natural frequencies of the M frame structures, identifying the vibration frequency amplification index, and generating the second resonance test result.

[0010] In a possible implementation, the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters are used to perform vibration cycle damage analysis on the N assembly connection points to locate the assembly defect node, and perform the following processing: using the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters as constraints, collecting N historical vibration cycle damage sequence data sets of the N assembly connection points; based on a long-short temporal memory network, using the N historical vibration cycle damage sequence data sets as training samples, training N cycle damage analysis models corresponding to the N assembly connection points; obtaining N damage feature time series of the N assembly connection points based on the N cycle damage analysis models; identifying the connection points whose damage features exceed a preset damage threshold and whose cycle duration is less than a preset cycle duration based on the N damage feature time series, and generating the assembly defect node.

[0011] In a possible implementation, the connection performance of the N assembly connection points is analyzed to generate N connection point performance parameters, and the following processing is performed: N connection features of the N assembly connection points are obtained; based on the N connection features, a connection performance comparison library identifies the connection point strength, stiffness and damping characteristics to generate the N connection point performance parameters, wherein the performance comparison library includes multiple groups of performance comparison samples, and any group of performance comparison samples includes a connection feature sample and identification information including the connection point strength, stiffness and damping characteristics.

[0012] The present application also provides a frame structure assembly test system for an electric tricycle, comprising: a frame structure and assembly connection point acquisition module, used to acquire M frame structures of a frame to be tested, and N assembly connection points for assembling the M frame structures, wherein M and N are integers greater than or equal to 1; a connection performance analysis module, used to perform connection performance analysis on the N assembly connection points, and generate N connection point performance parameters; a resonance test module, used to collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures under various driving conditions, and generate a first resonance test result, a second resonance test result, and a third resonance test result; a vibration cycle damage analysis module, used to perform vibration cycle damage analysis on the N assembly connection points using the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters, and locate assembly defect nodes; a frame structure assembly test result generation module, used to generate a frame structure assembly test result using the assembly defect nodes.

[0013] The present application proposes a frame structure assembly test method and system for an electric tricycle. First, M frame structures of the frame to be tested and N assembly connection points of the M frame structures are obtained, wherein M and N are integers greater than or equal to 1. Then, the connection performance of the N assembly connection points is analyzed to generate N connection point performance parameters. Then, M frame design parameters of the M frame structures are collected. Resonance tests between the frame and the road, between the frame structures, and between the frame and other tricycle structures are performed under various driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result. Then, the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters are used to perform vibration cycle damage analysis of the N assembly connection points to locate assembly defect nodes. Finally, the frame structure assembly test results are generated based on the assembly defect nodes, thereby achieving the technical effect of improving the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the accompanying drawings of the embodiment of the present invention will be briefly introduced below. A flow chart is used in the present application to illustrate the operations performed by the system according to the embodiment of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps can be processed in reverse order or simultaneously as needed. At the same time, other operations can also be added to these processes, or one or more operations can be removed from these processes.

[0015] Figure 1 A schematic flow chart of a frame structure assembly and testing method for an electric tricycle provided in an embodiment of the present application.

[0016] Figure 2 A schematic structural diagram of a frame structure assembly and testing system for an electric tricycle provided in an embodiment of the present application.

[0017] Explanation of the reference numerals: frame structure and assembly connection point acquisition module 10 , connection performance analysis module 20 , resonance test module 30 , vibration cycle damage analysis module 40 , frame structure assembly test result generation module 50 . DETAILED DESCRIPTION

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

[0019] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0020] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict, and the terms "first\second" involved are merely to distinguish similar objects and do not represent a specific ordering of objects. The terms "including" and "having" and any variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products, or devices. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of this application. The terms used herein are for the purpose of describing the embodiments of the present application only.

[0021] The present application embodiment provides a frame structure assembly test method for an electric tricycle, such as Figure 1 As shown, the method includes: Step S100, obtaining M frame structures of a frame to be tested and N assembly connection points for assembling the M frame structures, wherein M and N are integers greater than or equal to 1.

[0022] Specifically, the frame of the electric tricycle to be tested is disassembled or identified to determine which independent but interrelated frame structures (such as the frame body, rear frame, front fork, etc.) it is composed of. These frame structures are connected together in some way (such as welding, bolting, rivet connection, etc.) to form a complete frame. Next, identify and record the connection points between these frame structures. These connection points are the key parts for transmitting force and torque between the frame structures to ensure the overall performance and durability of the frame. For example, the frame body and the rear frame may be connected by several welding points or bolt connection points. Among them, M and N are integers greater than or equal to 1, indicating the number of frame structures and the number of assembly connection points.

[0023] Step S200, performing connection performance analysis on the N assembly connection points to generate N connection point performance parameters.

[0024] Specifically, the connection performance of each assembly connection point (the physical performance of the connection point when subjected to external forces and moments) is evaluated through theoretical analysis, experimental testing or simulation, including the strength, stiffness, durability and other aspects of the connection point. Based on the results of the connection performance analysis, corresponding performance parameters are generated for each connection point.

[0025] In a possible implementation, the connection performance of the N assembly connection points is analyzed to generate N connection point performance parameters, and step S200 further includes step S210 to obtain N connection features of the N assembly connection points. Specifically, the connection feature information of each assembly connection point is collected by consulting design drawings, manufacturing documents, etc. The connection feature refers to the characteristics of the assembly connection point in terms of design, material, manufacturing process, etc., including but not limited to the shape, size, material type, connection method (such as welding, riveting, bolt connection, etc.) of the connection point, and surface treatment of the connection. Establish a connection point information table to record all key features of each connection point one by one. For example, for welded connection points, it is necessary to record information such as welding type (such as butt welding, fillet welding), weld size, parent material, etc.; for bolted connections, it is necessary to record bolt specifications, preload force, gasket type, etc.

[0026] Step S220, based on the N connection features, the connection performance comparison library identifies the connection point strength, stiffness and damping characteristics, and generates the N connection point performance parameters, wherein the performance comparison library includes multiple groups of performance comparison samples, and any group of performance comparison samples includes connection feature samples and identification information including connection point strength, stiffness and damping characteristics. Specifically, the performance comparison library is a pre-established database, which contains connection features and their corresponding connection point strength, stiffness and damping characteristics data, which are derived from experimental tests, simulation analysis or historical experience and are used to quickly evaluate the performance of unknown connection points. The collected connection features are standardized to ensure that they are consistent with the sample data format in the performance comparison library. Using a machine learning algorithm (such as a decision tree, random forest, neural network, etc.) or a search and match method, the connection feature data is input and the corresponding connection point performance parameters are output. Among them, the connection point strength refers to the ability of the connection point to resist damage when subjected to external forces, which is measured by indicators such as tensile strength and shear strength. The stiffness of the connection point refers to the ability of the connection point to resist shape changes after being subjected to force, that is, the degree of stability of the connection point in maintaining its original shape. The damping characteristic describes the ability of the connection point to consume energy during vibration. Good damping characteristics can reduce vibration transmission and improve the stability of the structure. This implementation method can quickly and accurately evaluate the performance of a large number of connection points through a pre-established performance comparison library and automated analysis algorithm, and efficiently generate the performance parameters of each assembly connection point in the electric tricycle frame structure.

[0027] Step S300, collecting M frame design parameters of the M frame structures, performing resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures under various driving conditions, and generating a first resonance test result, a second resonance test result, and a third resonance test result.

[0028] Specifically, the design parameters of each frame structure are collected, such as material, size, shape, etc. The frame is subjected to resonance testing (assessing the vibration characteristics of the system by applying external excitation and measuring the response of the system) under various driving conditions (various road conditions and operating conditions that the vehicle may encounter during actual driving, such as flat roads, bumpy roads, turns, etc.), including the resonance between the frame and the road surface, the resonance between the frame structures, and the resonance between the frame and other tricycle structures (such as motors, batteries, etc.). Based on the data of the resonance test, the first resonance test results (frame and road resonance), the second resonance test results (resonance between frame structures), and the third resonance test results (frame and other tricycle structures resonance) are generated.

[0029] In a possible implementation, M frame design parameters of the M frame structures are collected, and resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures are respectively performed under various driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result. Step S300 further includes step S310, performing configuration of road surface conditions and driving parameters to establish the various driving conditions. Specifically, using simulation software (such as MATLAB / Simulink, ADAMS, etc.) or an actual test platform, according to the common use environment of the electric tricycle, different road surface conditions (road surface conditions that the vehicle contacts when driving, such as flat road surface, bumpy road surface, slope, etc.) and driving parameters (various parameters that affect the driving performance of the vehicle, such as speed, acceleration, load, etc.) are set to simulate various driving conditions.

[0030] Step S320, fitting the natural frequency of the whole frame and the natural frequencies of the M frame structures based on the M frame design parameters. Specifically, using finite element analysis software (such as ANSYS, Abaqus, etc.), a finite element model of the frame is established, material properties and geometric dimensions are input, and modal analysis is performed to obtain the natural frequencies of the whole frame and each frame structure. The natural frequency refers to the fixed frequency of an object during free vibration.

[0031] Step S330, determining the natural frequencies of other tricycle structures. Specifically, the finite element analysis technology is also used to calculate the natural frequencies of other key structures on the tricycle (such as the motor, battery pack, seat, etc.).

[0032] Step S340, testing the relationship between the road excitation frequency and the overall natural frequency of the frame under the multiple driving conditions, and generating the first resonance test result. Specifically, arranging acceleration sensors at key positions of the frame to monitor the vibration of the frame, recording the vibration data of the frame under different driving conditions, and recording the road excitation frequency (such as the vibration frequency caused by road roughness), analyzing the relationship between the road excitation frequency and the overall natural frequency of the frame, and determining whether resonance occurs.

[0033] Step S350, testing the vibration excitation relationship between any adjacent frame structures under the multiple driving conditions, performing resonance analysis between the frame structures in combination with the natural frequencies of the M frame structures, and generating the second resonance test result. Specifically, sensors are arranged between adjacent frame structures to monitor vibration transmission. In combination with the natural frequencies of the frame structures, vibration transmission data is analyzed to determine whether resonance between the frame structures occurs.

[0034] Step S360, testing the vibration excitation relationship between the frame and other tricycle structures under the multiple driving conditions, performing resonance analysis between the frame structures in combination with the natural frequency of the frame as a whole and the natural frequency of the other tricycle structures, and generating the third resonance test result. Specifically, sensors are arranged between the frame and other tricycle structures to monitor the vibration transmission. In combination with the natural frequency of the frame as a whole and the natural frequency of the other tricycle structures, the vibration transmission data is analyzed to determine whether resonance occurs between the frame and other structures. This implementation method comprehensively evaluates the resonance performance of the electric tricycle frame structure under different driving conditions, and can promptly discover possible resonance phenomena of the frame as a whole, between frame structures, and between the frame and other tricycle structures, thereby improving the comprehensiveness and accuracy of the test.

[0035] In a possible implementation, the configuration of the road surface state and driving parameters is performed to establish the multiple driving conditions, and step S310 further includes step S311, determining the matching electric tricycle of the frame to be tested, and collecting the factory recommended road environment constraints. Specifically, the factory recommended road environment information of the electric tricycle matched with the frame to be tested is obtained from channels such as the user manual, technical specifications or official website provided by the manufacturer, and the obtained road environment information is organized into structured data, including road surface type, maximum slope, recommended driving speed, etc. Among them, the factory recommended road environment is the driving road environment recommended by the manufacturer based on the performance and design characteristics of the electric tricycle to ensure the optimal performance and safety of the vehicle.

[0036] Step S312, based on the factory recommended road environment constraints, collect various road surface roughness parameters. Specifically, use road surface roughness measurement equipment (such as laser road profiler, level, etc.) to measure the roughness of the road surface in the recommended road environment. Process the measured data to calculate the road surface roughness parameters, such as the International Roughness Index (IRI), root mean square deviation (RMS), etc.

[0037] Step S313, collecting the driving speed constraints of the matching electric tricycle. Specifically, relevant information is obtained from the factory manual, technical specification or performance parameter table provided by the manufacturer of the electric tricycle, and the driving speed constraints of the vehicle under different working conditions are determined according to the obtained performance parameters, such as the maximum driving speed, economic cruising speed, braking distance, etc.

[0038] Step S314, construct various driving test parameters based on the driving speed constraint, wherein the various driving test parameters at least include parameters matching the electric tricycle under uniform speed, acceleration, deceleration, sudden braking and turning conditions. Specifically, analyze the dynamic characteristics of the electric tricycle under common driving conditions (such as uniform speed, acceleration, deceleration, sudden braking, turning, etc.), and determine key parameters such as speed, acceleration, deceleration, etc. under each condition. Combined with the driving speed constraint and condition analysis, construct various driving test parameters, such as the speed value during uniform driving, the acceleration curve during acceleration, the deceleration curve during deceleration, etc.

[0039] Step S315, extracting one parameter from each of the road surface roughness parameters and each of the driving test parameters for combination to generate the multiple driving conditions. Specifically, a permutation and combination method is adopted to select one parameter from each of the road surface roughness parameters and the driving test parameters for combination to form multiple driving conditions. For example, different road surface roughnesses can be combined with conditions such as uniform speed driving, accelerated driving, and decelerated driving. This implementation method configures driving conditions according to the factory recommended road environment and performance parameters of the electric tricycle, which is closer to the actual use of the vehicle and improves the accuracy and practicality of the test.

[0040] In a possible implementation, the relationship between the road excitation frequency and the overall natural frequency of the frame is tested under the multiple driving conditions to generate the first resonance test result. Step S340 further includes step S341, in which the frame to be tested is virtually assembled with other tricycle structures, and the vibration modeling data under actual working conditions is collected for digital twin modeling to establish a twin tricycle operation simulation model. Specifically, computer-aided design (CAD) software is used to perform virtual assembly according to the geometric dimensions and assembly relationship of the frame to be tested and other tricycle structures to form a complete virtual tricycle model. Vibration data of the tricycle under actual working conditions is collected through sensors, including vibration frequency, amplitude, phase, etc. Using computer-aided engineering (CAE) software and digital twin technology, the collected vibration data is input into the virtual tricycle model, parameterized and refined modeling is performed, and a digital twin model that can reflect the dynamic characteristics of the tricycle under actual working conditions is formed.

[0041] Step S342, simulate the multiple driving conditions with the twin tricycle operation simulation model, and record multiple road excitation frequencies. Specifically, according to the multiple driving conditions established in step S310, set the operating condition parameters in the simulation software, including road surface flatness, driving speed, acceleration, etc. Run the twin tricycle operation simulation model in the simulation software to simulate the operating state of the tricycle under different working conditions. Record the data of road excitation frequency during the simulation process, which reflects the excitation effect of the road on the tricycle under different working conditions. Among them, the road excitation frequency refers to the vibration frequency caused by the uneven road surface.

[0042] Step S343, analyze the influence of the multiple road excitation frequencies on the overall natural frequency of the frame, and generate the first resonance test result. Specifically, perform spectrum analysis on the simulated road excitation frequency to determine its main frequency components. Compare the road excitation frequency with the overall natural frequency of the frame to evaluate whether resonance occurs (the phenomenon that the structural vibration amplitude increases significantly when the external excitation frequency is close to or equal to the structural natural frequency). When resonance occurs, the vibration amplitude of the frame will increase significantly, which may cause structural damage or performance degradation. Based on the results of the resonance evaluation, generate the first resonance test result, including information such as the frequency and amplitude of the resonance. This implementation method improves the accuracy of resonance evaluation through digital twin technology and simulation analysis.

[0043] In a possible implementation, the vibration excitation relationship between any adjacent frame structures is tested under the multiple driving conditions, and the resonance analysis between the frame structures is performed in combination with the natural frequencies of the M frame structures to generate the second resonance test result. Step S350 further includes step S351, determining the adjacent first frame structure and the second frame structure. Specifically, the CAD drawing of the frame is consulted, and according to the assembly relationship and geometric dimensions in the drawing, two adjacent frame structures in the frame to be tested, namely, the first frame structure and the second frame structure, are identified and determined.

[0044] Step S352, collecting connection features of the assembly connection point between the first frame structure and the second frame structure, wherein the connection features include a connection method and a contact area. Specifically, using a measuring tool or a sensor, the connection method used at the connection point, i.e., the technical means used to connect the frame structures, such as welding, riveting, bolt connection, etc., is recorded, and at the same time, the contact area of ​​the connection point, i.e., the area where the two frame structures contact each other at the connection point, is measured.

[0045] Step S353, performing vibration coupling analysis based on the connection characteristics of the assembly connection points to generate a first vibration coupling relationship. Specifically, in the finite element analysis software, a vibration model of the frame structure is established according to the geometric shape, material properties and connection characteristics of the frame. According to the actual use of the frame, boundary conditions such as fixed constraints, loads, etc. are set. The finite element analysis software is run to perform vibration analysis on the frame structure to obtain the vibration coupling relationship between the first frame structure and the second frame structure, that is, the degree of mutual influence between the two structures during the vibration process.

[0046] Step S354, optimize the twin tricycle operation simulation model with the first vibration coupling relationship, simulate the multiple driving conditions through the optimized simulation model, record the vibration frequencies corresponding to the M frame structures respectively, and compare them with the natural frequencies of the M frame structures, identify the vibration frequency amplification index, and generate the second resonance test result. Specifically, in the digital twin model, the connection parameters between the frame structures, such as connection stiffness, damping, etc., are adjusted according to the vibration coupling relationship. Using simulation analysis software, the optimized digital twin model is simulated and analyzed under multiple driving conditions, and the vibration frequency of the frame structure under different conditions is recorded. The vibration frequency obtained by simulation is compared with the natural frequency of the frame structure, and the vibration frequency amplification index is identified, that is, the situation where the vibration frequency is close to or equal to the natural frequency. When the vibration frequency is close to or equal to the natural frequency, the index value is higher. According to the vibration frequency amplification index, a second resonance test result is generated, including information such as the frequency, position, and amplitude of the resonance. This implementation method more accurately describes the interaction relationship between the frame structures by collecting connection feature data and performing vibration coupling analysis, thereby improving the accuracy of resonance evaluation.

[0047] The process of obtaining the third resonance test result is similar to that of the second resonance test result, except that the object of analysis is the vibration coupling relationship between the frame and other tricycle structures. It is also necessary to collect connection feature data, perform vibration coupling analysis, optimize the simulation model, and perform simulation analysis under various driving conditions. Finally, the resonance between the frame and other tricycle structures is identified based on the simulation results, and the third resonance test result is generated.

[0048] Step S400, performing vibration cycle damage analysis on N assembly connection points based on the first resonance test result, the second resonance test result, the third resonance test result and the performance parameters of the N connection points to locate assembly defect nodes.

[0049] Specifically, vibration cycle damage analysis is performed on each assembly connection point in combination with the resonance test results and connection point performance parameters, including evaluation of the fatigue life and damage accumulation of the connection point under a vibration environment. Based on the results of the vibration cycle damage analysis, identify and locate those connection points that may have defects or high risks, which are the key factors that lead to the degradation or failure of the overall performance of the frame. Among them, vibration cycle damage refers to the damage and fatigue caused by cyclic stress in the structure under a vibration environment.

[0050] In a possible implementation, the vibration cycle damage analysis of N assembly connection points is performed based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters to locate the assembly defect node, and step S400 further includes step S410, using the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters as constraints to collect N historical vibration cycle damage sequence data sets of N assembly connection points. Specifically, the vibration cycle damage sequence data of each assembly connection point (a total of N) is collected from the historical data. These data are derived from previous test records, simulation results or monitoring data in actual operation, and each data point contains information such as vibration amplitude, frequency, and damage accumulation of the connection point under specific working conditions. The damage data of each connection point is arranged in chronological order to form a vibration cycle damage sequence data set. When collecting the historical vibration cycle damage sequence data set, it is necessary to comprehensively consider the influence of the resonance test results and the connection point performance parameters. These constraints are used to ensure that the collected data can truly and accurately reflect the vibration characteristics and damage of the frame structure, providing a reliable basis for subsequent analysis and evaluation.

[0051] Step S420, based on the long short-term memory network, the N historical vibration cycle damage sequence data sets are used as training samples to train N cycle damage analysis models corresponding to the N assembly connection points. Specifically, a long short-term memory network (LSTM, Long Short-Term Memory) model is constructed using a deep learning framework (such as TensorFlow or PyTorch). Each historical vibration cycle damage sequence data set collected in step S410 is used as a training sample and input into the LSTM model for training. By adjusting the model parameters and minimizing the prediction error, the model can accurately predict the vibration cycle damage of the connection point. Use methods such as cross-validation to evaluate the performance of the model to ensure the generalization ability of the model.

[0052] Step S430, based on the N cycle damage analysis model analysis, N damage feature time series of N assembly connection points are obtained. Specifically, the trained LSTM model and the vibration test data of the current frame are used to perform vibration cycle damage analysis on the N assembly connection points of the current frame to be tested, and the damage feature time series of each connection point is obtained. The damage feature time series is a feature sequence that describes the damage accumulation of the connection point over time in the vibration cycle.

[0053] Step S440, based on the N damage feature time series, identify the connection points whose damage features exceed the preset damage threshold and whose cycle duration is less than the preset cycle duration, and generate the assembly defect node. Specifically, according to industry standards, thresholds for damage features and cycle durations are set. Among them, the preset damage threshold is a standard value used to judge whether the damage to the connection point is serious. The preset cycle duration is a standard time used to judge whether the damage accumulation rate of the connection point is too fast. Traverse the damage feature time series of all connection points, compare the damage feature of each connection point with the preset threshold, and check whether its cycle duration is less than the preset cycle duration. Mark the connection points that meet the conditions as assembly defect nodes. This implementation method can more accurately evaluate the vibration cycle damage of the frame structure by collecting and analyzing historical data. Machine learning models such as LSTM can automatically learn the characteristics and laws of connection point damage, reduce the subjectivity and uncertainty of manual judgment, and thus improve the accuracy and reliability of the test.

[0054] Step S500: generating a vehicle frame structure assembly test result using the assembly defect node.

[0055] Specifically, based on the located assembly defect nodes, the frame structure assembly test results are generated. This result contains detailed information about the defect nodes (such as location, type, risk, etc.), as well as possible repair suggestions or improvement plans. The test results are presented to relevant personnel (such as designers, manufacturers, test engineers, etc.) in the form of a report so that subsequent repairs, improvements or decisions can be made based on the test results. The embodiment of the present application adopts the method of obtaining M frame structures and N assembly connection points of the frame to be tested, performing connection performance analysis on the connection points, collecting frame design parameters and performing resonance tests under various driving conditions, performing vibration cycle damage analysis based on the resonance test results and connection point performance parameters, locating assembly defect nodes and other technical means, and accurately reflecting the performance of the frame under various driving conditions through resonance testing and vibration cycle damage analysis, thereby achieving the technical effect of improving test accuracy.

[0056] In the above, refer to Figure 1 A frame structure assembly test method for an electric tricycle according to an embodiment of the present invention is described in detail. Figure 2 A frame structure assembly test system for an electric tricycle according to an embodiment of the present invention is described.

[0057] A frame structure assembly test system for an electric tricycle according to an embodiment of the present invention is used to solve the technical problem that the test accuracy is difficult to ensure in the prior art, and achieve the technical effect of improving the test accuracy. A frame structure assembly test system for an electric tricycle includes: a frame structure and assembly connection point acquisition module 10, a connection performance analysis module 20, a resonance test module 30, a vibration cycle damage analysis module 40, and a frame structure assembly test result generation module 50.

[0058] The frame structure and assembly connection point acquisition module 10 is used to acquire M frame structures of the frame to be tested, and N assembly connection points for assembling the M frame structures, wherein M and N are integers greater than or equal to 1; the connection performance analysis module 20 is used to perform connection performance analysis on the N assembly connection points to generate N connection point performance parameters; the resonance test module 30 is used to collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures under various driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result; the vibration cycle damage analysis module 40 is used to perform vibration cycle damage analysis on the N assembly connection points using the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters to locate assembly defect nodes; the frame structure assembly test result generation module 50 is used to generate a frame structure assembly test result using the assembly defect nodes.

[0059] The specific configuration of the resonance test module 30 will be described in detail below. As described above, the M frame design parameters of the M frame structures are collected, and resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures are performed under multiple driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result. The resonance test module 30 may further include: a multiple driving condition establishment unit for executing the configuration of the road surface state and driving parameters to establish the multiple driving conditions; a natural frequency determination unit for fitting the overall natural frequency of the frame and the natural frequencies of the M frame structures based on the M frame design parameters to determine the natural frequencies of other tricycle structures; a first resonance test result generation unit for generating the first resonance test result in the multiple driving conditions. The first resonance test result is generated by testing the relationship between the road excitation frequency and the overall natural frequency of the frame under the multiple driving conditions; the second resonance test result generating unit is used to test the vibration excitation relationship between any adjacent frame structures under the multiple driving conditions, and perform resonance analysis between the frame structures in combination with the M frame structure natural frequencies to generate the second resonance test result; the third resonance test result generating unit is used to test the vibration excitation relationship between the frame and other tricycle structures under the multiple driving conditions, and perform resonance analysis between the frame structures in combination with the overall natural frequency of the frame and the natural frequencies of the other tricycle structures to generate the third resonance test result.

[0060] Among them, the configuration of road surface conditions and driving parameters is executed to establish the multiple driving conditions, and the multiple driving condition establishment unit may further include: a factory recommended road environment constraint collection subunit is used to determine the matching electric tricycle of the frame to be tested, and collect the factory recommended road environment constraints; a road surface flatness parameter collection subunit is used to collect various road surface flatness parameters based on the factory recommended road environment constraints; a driving speed constraint collection subunit is used to collect the driving speed constraints of the matching electric tricycle; a driving test parameter construction subunit is used to construct various driving test parameters based on the driving speed constraints, wherein the various driving test parameters at least include parameters of the matching electric tricycle under uniform speed, acceleration, deceleration, sudden braking and turning conditions; a multiple driving condition generation subunit is used to extract one parameter from each of the road surface flatness parameters and each of the driving test parameters, and combine them to generate the multiple driving conditions.

[0061] Among them, the relationship between the road excitation frequency and the overall natural frequency of the frame is tested under the multiple driving conditions to generate the first resonance test result. The first resonance test result generating unit may further include: a twin tricycle operation simulation model establishing subunit for virtually assembling the frame to be tested with other tricycle structures, and collecting vibration modeling data under actual working conditions for digital twin modeling to establish a twin tricycle operation simulation model; a simulation subunit for simulating the multiple driving conditions with the twin tricycle operation simulation model and recording multiple road excitation frequencies; a first resonance test result generating subunit for analyzing the influence of the multiple road excitation frequencies on the overall natural frequency of the frame to generate the first resonance test result.

[0062] Wherein, the vibration excitation relationship between any adjacent frame structures is tested under the multiple driving conditions, and the resonance analysis between the frame structures is performed in combination with the natural frequencies of the M frame structures to generate the second resonance test result. The second resonance test result generating unit may further include: an adjacent frame structure determining subunit for determining the adjacent first frame structure and the second frame structure; a connection feature collecting subunit for collecting the connection features of the assembly connection points between the first frame structure and the second frame structure, wherein the connection features include the connection mode and the contact area; a vibration coupling analyzing subunit for performing vibration coupling analysis based on the connection features of the assembly connection points to generate a first vibration coupling relationship; a second resonance test result generating subunit for optimizing the twin tricycle operation simulation model with the first vibration coupling relationship, simulating the multiple driving conditions with the optimized simulation model, recording the vibration frequencies corresponding to the M frame structures respectively, and comparing them with the natural frequencies of the M frame structures, identifying the vibration frequency amplification index, and generating the second resonance test result.

[0063] The specific configuration of the vibration cycle damage analysis module 40 will be described in detail below. As described above, the vibration cycle damage analysis of N assembly connection points is performed based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters to locate the assembly defect node. The vibration cycle damage analysis module 40 may further include: a historical vibration cycle damage sequence data set acquisition unit is used to collect N historical vibration cycle damage sequence data sets of N assembly connection points based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters as constraints; a cycle damage analysis model training unit is used to train N cycle damage analysis models corresponding to N assembly connection points based on a long-short time series memory network and using the N historical vibration cycle damage sequence data sets as training samples; a damage feature time series acquisition unit is used to acquire N damage feature time series of N assembly connection points based on the N cycle damage analysis models; an assembly defect node generation unit is used to identify connection points whose damage features exceed a preset damage threshold and whose cycle duration is less than a preset cycle duration based on the N damage feature time series, and generate the assembly defect node.

[0064] The specific configuration of the connection performance analysis module 20 will be described in detail below. As described above, the connection performance analysis of the N assembly connection points is performed to generate N connection point performance parameters. The connection performance analysis module 20 may further include: a connection feature acquisition unit for acquiring N connection features of the N assembly connection points; a connection point performance parameter generation unit for identifying the connection point strength, stiffness and damping characteristics based on the N connection features and the connection performance comparison library to generate the N connection point performance parameters, wherein the performance comparison library includes multiple groups of performance comparison samples, and any group of performance comparison samples includes a connection feature sample and identification information including the connection point strength, stiffness and damping characteristics.

[0065] A frame structure assembly test system for an electric tricycle provided in an embodiment of the present invention can execute a frame structure assembly test method for an electric tricycle provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0066] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, any number of different modules may be used and run on the user terminal and / or server, and the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0067] The above specific implementation manner does not constitute a limitation to the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application. In some cases, the actions or steps recorded in the present application can be performed in an order different from that in the embodiment and can still achieve the desired results. In addition, the process depicted in the accompanying drawings does not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A frame structure assembly test method for an electric tricycle, characterized in that: include: Obtaining M frame structures of a frame to be tested, and N assembly connection points for assembling the M frame structures, wherein M and N are integers greater than or equal to 1; Performing connection performance analysis on the N assembly connection points to generate N connection point performance parameters; Collecting M frame design parameters of the M frame structures, performing resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures under various driving conditions, and generating a first resonance test result, a second resonance test result, and a third resonance test result; Performing vibration cycle damage analysis on N assembly connection points based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters to locate assembly defect nodes; The frame structure assembly test result is generated using the assembly defect node.

2. The frame structure assembly test method of an electric tricycle as claimed in claim 1, characterized in that: The M frame design parameters of the M frame structures are collected, and resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures are performed under various driving conditions to generate a first resonance test result, a second resonance test result, and a third resonance test result, including: Execute configuration of road surface conditions and driving parameters to establish the multiple driving conditions; Fitting the overall natural frequency of the frame and the M natural frequencies of the frame structure based on the M frame design parameters; Determine the natural frequencies of other tricycle structures; Testing the relationship between the road excitation frequency and the overall natural frequency of the frame under the multiple driving conditions to generate the first resonance test result; Testing the vibration excitation relationship between any adjacent frame structures under the multiple driving conditions, performing resonance analysis between the frame structures in combination with the M frame structure natural frequencies, and generating the second resonance test result; The vibration excitation relationship between the frame and other tricycle structures is tested under the multiple driving conditions, and resonance analysis between the frame structures is performed in combination with the overall natural frequency of the frame and the natural frequencies of the other tricycle structures to generate the third resonance test result.

3. The frame structure assembly test method of an electric tricycle as claimed in claim 2, characterized in that: Execute the configuration of road surface conditions and driving parameters to establish the multiple driving conditions, including: Determine the matching electric tricycle of the frame to be tested, and collect factory recommended road environment constraints; Based on the factory recommended road environment constraints, collecting various road surface smoothness parameters; Collecting the driving speed constraint of the matching electric tricycle; Constructing various driving test parameters based on the driving speed constraint, wherein the various driving test parameters at least include parameters matching the electric tricycle in uniform speed, acceleration, deceleration, emergency braking and turning states; A parameter is extracted from each of the road surface roughness parameters and each of the driving test parameters, and the parameters are combined to generate the multiple driving conditions.

4. The frame structure assembly test method of an electric tricycle as claimed in claim 2, characterized in that: Testing the relationship between the road excitation frequency and the overall natural frequency of the frame under the multiple driving conditions to generate the first resonance test result includes: The frame to be tested is virtually assembled with other tricycle structures, and vibration modeling data under actual working conditions is collected for digital twin modeling to establish a twin tricycle operation simulation model; Simulating the multiple driving conditions using the twin tricycle operation simulation model, and recording multiple road surface excitation frequencies; The influence of the multiple road excitation frequencies on the overall natural frequency of the frame is analyzed to generate the first resonance test result.

5. The frame structure assembly test method of an electric tricycle as claimed in claim 4, characterized in that: Testing the vibration excitation relationship between any adjacent frame structures under the multiple driving conditions, performing resonance analysis between the frame structures in combination with the M frame structure natural frequencies, and generating the second resonance test result, including: determining an adjacent first frame structure and a second frame structure; collecting connection characteristics of an assembly connection point between the first frame structure and the second frame structure, wherein the connection characteristics include a connection mode and a contact area; Performing a vibration coupling analysis based on the connection characteristics of the assembly connection points to generate a first vibration coupling relationship; The twin tricycle operation simulation model is optimized based on the first vibration coupling relationship, the multiple driving conditions are simulated through the optimized simulation model, the vibration frequencies corresponding to the M frame structures are recorded, and compared with the natural frequencies of the M frame structures, the vibration frequency amplification index is identified, and the second resonance test result is generated.

6. The frame structure assembly test method of an electric tricycle as claimed in claim 1, characterized in that: Performing vibration cycle damage analysis on N assembly connection points based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters to locate assembly defect nodes includes: Taking the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters as constraints, collecting N historical vibration cycle damage sequence data sets of N assembly connection points; Based on the long short-term memory network, the N historical vibration cycle damage sequence data sets are used as training samples to train N cycle damage analysis models corresponding to N assembly connection points; Obtaining N damage feature time series of N assembly connection points based on the N cycle damage analysis models; Based on the N damage feature time series, a connection point whose damage feature exceeds a preset damage threshold and whose cycle duration is less than a preset cycle duration is identified to generate the assembly defect node.

7. The frame structure assembly test method of an electric tricycle as claimed in claim 1, characterized in that: Performing connection performance analysis on the N assembly connection points to generate N connection point performance parameters, including: Obtaining N connection features of the N assembly connection points; Based on the N connection features, the connection performance comparison library identifies the connection point strength, stiffness and damping characteristics, and generates the N connection point performance parameters, wherein the performance comparison library includes multiple groups of performance comparison samples, and any group of performance comparison samples includes connection feature samples and identification information including connection point strength, stiffness and damping characteristics.

8. A frame structure assembly test system for an electric tricycle, characterized in that: The system is used to implement the frame structure assembly test method of an electric tricycle according to any one of claims 1 to 7, and the system comprises: A frame structure and assembly connection point acquisition module, used to acquire M frame structures of the frame to be tested, and N assembly connection points for assembling the M frame structures, wherein M and N are integers greater than or equal to 1; A connection performance analysis module, used to perform connection performance analysis on the N assembly connection points to generate N connection point performance parameters; A resonance test module, used to collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road surface, between the frame structures, and between the frame and other tricycle structures under various driving conditions, and generate a first resonance test result, a second resonance test result, and a third resonance test result; A vibration cycle damage analysis module, used to perform vibration cycle damage analysis on N assembly connection points based on the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters, and locate assembly defect nodes; The frame structure assembly test result generating module is used to generate the frame structure assembly test result based on the assembly defect node.

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