A method and system for testing the assembly of a frame structure of an electric tricycle

Abstract

The application discloses an electric tricycle frame structure assembly test method and system, and relates to the related field of frame testing. The method comprises the following steps: obtaining M frame structures of a frame to be tested, assembling N assembly connection points of the M frame structures; performing connection performance analysis on the connection points, and generating N connection point performance parameters; collecting M frame design parameters, and respectively performing resonance tests between the frame and the road surface, the frame structure, and the frame and other tricycle structures under multiple driving conditions; performing vibration cycle damage analysis on the N assembly connection points by using the first resonance test result, the second resonance test result, the third resonance test result and the N connection point performance parameters, positioning an assembly defect node; and generating a frame structure assembly test result by using the assembly defect node. The technical problem that the test precision of the existing electric tricycle frame structure assembly test is difficult to guarantee 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, in particular to a frame structure assembly testing method and system of an electric tricycle. BACKGROUND

[0002] As a core component of an electric tricycle, the frame structure design and assembly quality are directly related to the safety, stability and service life of the vehicle. In the existing frame structure assembly testing of an electric tricycle, 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-carrying capacity of the frame under static conditions, but cannot simulate the dynamic conditions in actual driving. Due to the single test condition, the comprehensiveness and accuracy of the test are insufficient.

[0003] At present, in the related art, the frame structure assembly testing of an electric tricycle has the technical problem that the testing accuracy is difficult to guarantee. SUMMARY

[0004] The present application provides a frame structure assembly testing method and system of an electric tricycle, which acquires M frame structures and N assembly connection points of a frame to be tested, analyzes the connection performance of the connection points, collects frame design parameters and performs resonance testing under multiple driving conditions, performs vibration cycle damage analysis based on the resonance testing results and connection point performance parameters, and locates assembly defect nodes. Through resonance testing and vibration cycle damage analysis, the performance of the frame under multiple driving conditions is accurately reflected, and the technical effect of improving testing accuracy is achieved.

[0005] The present application provides a frame structure assembly testing method of an electric tricycle, comprising: acquiring M frame structures of a frame to be tested and 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, and performing resonance testing between the frame and the road, the frame structure, and the frame and other tricycle structures under multiple driving conditions to generate first, second and third resonance testing results; performing vibration cycle damage analysis on the N assembly connection points based on the first, second and third resonance testing results and the N connection point performance parameters to locate assembly defect nodes; and generating a frame structure assembly testing result based on the assembly defect nodes.

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

[0007] In a possible implementation, configuration of road surface states and driving parameters is performed to establish the multiple driving conditions, and the following processing is performed: a matching electric three-wheeled vehicle of the frame to be tested is determined, and factory-recommended road environment constraints are collected; based on the factory-recommended road environment constraints, each road flatness parameter is collected; a driving speed constraint of the matching electric three-wheeled vehicle is collected; each driving test parameter is constructed based on the driving speed constraint, where the each driving test parameter at least includes parameters of the matching electric three-wheeled vehicle in uniform speed, acceleration, deceleration, sudden braking, and turning states; one parameter is extracted from each road flatness parameter and each driving test parameter respectively to generate the multiple driving conditions.

[0008] In a possible implementation, a relationship between road surface excitation frequencies and the frame overall natural frequencies is tested under the multiple driving conditions to generate the first resonance test results, and the following processing is performed: the frame to be tested and other three-wheeled vehicle structures are virtually assembled, vibration modeling data under actual working conditions are collected to perform digital twin modeling, and a twin three-wheeled vehicle operation simulation model is established; the multiple driving conditions are simulated by using the twin three-wheeled vehicle operation simulation model, and multiple road surface excitation frequencies are recorded; an influence of the multiple road surface excitation frequencies on the frame overall natural frequencies is analyzed to generate the first resonance test results.

[0009] In a possible implementation, in the plurality of driving conditions, the vibration excitation relationship between any adjacent frame structures is tested, resonance analysis between the frame structures is performed in combination with the M frame structure natural frequencies, the second resonance test result is generated, and the following processing is performed: a first frame structure and a second frame structure adjacent to each other are determined; connection characteristics of an assembly connection point between the first frame structure and the second frame structure are collected, where the connection characteristics include a connection mode and a contact area; vibration coupling analysis is performed based on the connection characteristics of the assembly connection point to generate a first vibration coupling relationship; the twin tricycle operation simulation model is optimized based on the first vibration coupling relationship, the plurality of driving conditions are simulated through the optimized simulation model, vibration frequencies corresponding to the M frame structures are recorded, and the vibration frequencies are compared with the M frame structure natural frequencies to identify a vibration frequency amplification index, and the second resonance test result is generated.

[0010] In a possible implementation, 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, and an assembly defect node is located, and the following processing is performed: N historical vibration cycle damage sequence data sets of N assembly connection points are collected as constraints based on the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters; based on a 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; N damage feature time sequences of the N assembly connection points are analyzed and obtained based on the N cycle damage analysis models; based on the N damage feature time sequences, a connection point whose damage feature exceeds a preset damage threshold and whose cycle length is less than a preset cycle length is identified, and the assembly defect node is generated.

[0011] In a possible implementation, connection performance analysis of the N assembly connection points is performed to generate N connection point performance parameters, and the following processing is performed: N connection characteristics of the N assembly connection points are obtained; based on the N connection characteristics, connection point strength, stiffness, and damping characteristic identification is performed on a connection performance comparison library to generate the N connection point performance parameters, where the performance comparison library includes a plurality of performance comparison samples, and any performance comparison sample includes a connection characteristic sample and identification information including connection point strength, stiffness, and damping characteristic.

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

[0013] The frame structure assembly test method and system of the electric tricycle provided in the application first acquire M frame structures of a frame to be tested and N assembly connection points of the M frame structures, wherein M and N are integers greater than or equal to 1, then perform connection performance analysis on the N assembly connection points to generate N connection point performance parameters, acquire M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road surface, the frame structure and other tricycle structures under multiple driving conditions to generate first, second and third resonance test results, then perform vibration cycle damage analysis on the N assembly connection points based on the first, second and third resonance test results and the N connection point performance parameters to locate an assembly defect node, and finally generate a frame structure assembly test result based on the assembly defect node, thereby achieving the technical effect of improving test accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings of the embodiments of the application will be briefly introduced as follows. In the present application, a flowchart is used to illustrate the operations performed by the system according to the embodiments of the application. It should be understood that the foregoing or the following operations are not necessarily performed in sequence. On the contrary, various steps can be processed in reverse order or simultaneously according to needs. Meanwhile, other operations can be added to these processes, or one or more steps of operations can be removed from these processes.

[0015] Figure 1 A flowchart of the frame structure assembly test method of the electric tricycle provided in the embodiments of the application.

[0016] Figure 2 A structural schematic diagram of an electric tricycle frame structure assembly test system provided by an embodiment of the application is shown.

[0017] Reference signs: 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 a summary of the technical solutions of the application. In order to enable the technical means of the application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, characteristics and advantages of the application to be more apparent and easy to understand, the following specific embodiments of the application are described.

[0019] In order to make the purposes, technical solutions and advantages of the application more clear, the following will further describe the application with reference to the drawings, and the described embodiments should not be regarded as limiting the application. All other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the application.

[0020] In the following description, “some embodiments” are related to a subset of all possible embodiments, but it can be understood that “some embodiments” can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict. The term “first\second” is only to distinguish similar objects, and does not represent a specific order of the objects. The terms “include” and “have” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or server including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or modules 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 understood by those skilled in the art to which the application belongs. The terms used herein are only for the purpose of describing the embodiments of the application.

[0021] An electric tricycle frame structure assembly test method is provided by an embodiment of the application, as shown in Figure 1 The method comprises the following steps:

[0022] In step S100, M frame structures of a to-be-tested frame are acquired, and N assembly connection points of the M frame structures are assembled, wherein M and N are integers greater than or equal to 1.

[0023] Specifically, the electric tricycle frame 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, bolt connection, rivet connection, etc.) to form a complete frame. Then, the connection points between these frame structures are identified and recorded, which are the key positions for transmitting force and torque between frame structures to ensure the overall performance and durability of the frame. For example, the frame body and the rear frame may be connected through several welding points or bolt connection points. Wherein, M and N are integers greater than or equal to 1, representing the number of frame structures and the number of assembly connection points.

[0024] In step S200, the connection performance analysis of the N assembly connection points is performed to generate N connection point performance parameters.

[0025] Specifically, the connection performance (the physical performance of the connection point when subjected to external force and torque) of each assembly connection point is evaluated through theoretical analysis, experimental testing or simulation, etc., including strength, stiffness, durability, etc. of the connection point. According to the results of the connection performance analysis, the corresponding performance parameters are generated for each connection point.

[0026] In one possible implementation, the connection performance analysis of the N assembly connection points to generate N connection point performance parameters, step S200 further includes step S210, obtaining N connection characteristics of the N assembly connection points. Specifically, by consulting design drawings, manufacturing documents, etc., the connection characteristic information of each assembly connection point is collected. The connection characteristics refer to the characteristics of the assembly connection point in design, material, manufacturing process, etc., including but not limited to the shape, size, material type, connection method (such as welding, riveting, bolt connection, etc.) and surface treatment of the connection, etc. A connection point information table is established to record all key characteristics of each connection point one by one. For example, for a welded connection point, the welding type (such as butt welding, fillet welding), weld size, base material, etc. information needs to be recorded; for bolt connection, bolt specification, pre-tightening force, gasket type, etc. needs to be recorded.

[0027] In step S220, based on the N connection features, the connection performance comparison library is connected to identify the connection point strength, stiffness and damping characteristics, and the N connection point performance parameters are generated, wherein the performance comparison library includes a plurality of performance comparison samples, and any performance comparison sample includes a connection feature sample and identification information containing connection point strength, stiffness and damping characteristics. Specifically, the performance comparison library is a pre-established database containing connection features and their corresponding connection point strength, stiffness and damping characteristics data, which are derived from experimental tests, simulation analysis or historical experience, for quickly evaluating the performance of unknown connection points. The collected connection features are standardized to ensure consistency with the sample data format in the performance comparison library. Machine learning algorithms (such as decision trees, random forests, neural networks, etc.) or lookup matching methods are used to input connection feature data and output corresponding connection point performance parameters. 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 connection point stiffness refers to the ability of the connection point to resist shape changes after being stressed, i.e., the stability of the connection point to maintain its original shape. Damping characteristics describe the ability of the connection point to dissipate energy during vibration, and 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 and efficiently generate performance parameters for each assembled connection point in the electric three-wheeled vehicle frame structure by pre-establishing a performance comparison library and automated analysis algorithms.

[0028] In step S300, M frame design parameters of the M frame structures are collected, resonance tests between the frame and the road, the frame structures, and the frame and other three-wheeled vehicle structures are performed under various driving conditions to generate first, second and third resonance test results.

[0029] Specifically, the design parameters of each frame structure, such as materials, sizes, shapes, etc., are collected. 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.), resonance tests (evaluating the vibration characteristics of a system by applying external excitation and measuring the response of the system) are performed on the frame, including resonance between the frame and the road, resonance between the frame structures, and resonance between the frame and other three-wheeled vehicle structures (such as motors, batteries, etc.). According to the data of the resonance test, the first resonance test result (frame and road resonance), the second resonance test result (frame structure resonance) and the third resonance test result (frame and other three-wheeled vehicle structure resonance) are generated.

[0030] In a possible implementation, M frame design parameters of the M frame structures are collected, resonance tests between the frame and the road surface, the frame structure, and the frame and other three-wheeled vehicle structures are respectively performed under multiple driving conditions, and first, second, and third resonance test results are generated. Step S300 further includes step S310 of performing configuration of road surface states and driving parameters to establish the multiple driving conditions. Specifically, different road surface states (road surface conditions contacted by the vehicle during driving, such as flat road surface, bumpy road surface, slope, and the like) and driving parameters (various parameters affecting the driving performance of the vehicle, such as speed, acceleration, load, and the like) are set according to common use environments of the electric three-wheeled vehicle by using simulation software (such as MATLAB / Simulink, ADAMS, and the like) or an actual test platform, and the multiple driving conditions are simulated.

[0031] Step S320 is based on the M frame design parameters to fit the overall frame natural frequency and the M frame structure natural frequencies. Specifically, a finite element model of the frame is established by using finite element analysis software (such as ANSYS, Abaqus, and the like), material properties and geometric dimensions are input, modal analysis is performed, and the overall frame and each frame structure natural frequency is obtained. The natural frequency refers to the fixed frequency of the object when it is free to vibrate.

[0032] Step S330 is to determine the natural frequency of other three-wheeled vehicle structures. Specifically, finite element analysis technology is also used to calculate the natural frequency of other key structures (such as motors, battery packs, seats, and the like) on the three-wheeled vehicle.

[0033] Step S340 is to test the relationship between the road surface excitation frequency and the overall frame natural frequency under the multiple driving conditions, and generate the first resonance test result. Specifically, acceleration sensors are arranged at key positions of the frame to monitor the vibration of the frame, vibration data of the frame is recorded under different driving conditions, road surface excitation frequencies (such as vibration frequencies caused by road unevenness) are recorded at the same time, the relationship between the road surface excitation frequency and the overall frame natural frequency is analyzed, and it is determined whether resonance occurs.

[0034] Step S350 is 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. Specifically, sensors are arranged between adjacent frame structures to monitor vibration transmission. In combination with the frame structure natural frequencies, vibration transmission data is analyzed to determine whether resonance occurs between the frame structures.

[0035] In step S360, the vibration excitation relationship between the frame and other three-wheeled vehicle structures is tested under the plurality of driving conditions, resonance analysis between the frame structures is performed in combination with the overall natural frequency of the frame and the natural frequency of the other three-wheeled vehicle structures, and the third resonance test result is generated. Specifically, sensors are arranged between the frame and the other three-wheeled vehicle structures to monitor the vibration transmission. In combination with the overall natural frequency of the frame and the natural frequency of the other three-wheeled vehicle structures, the vibration transmission data is analyzed to determine whether resonance occurs between the frame and the other structures. This implementation mode comprehensively evaluates the resonance performance of the electric three-wheeled vehicle frame structure under different driving conditions, and can timely find the resonance phenomenon that may exist between the overall frame, the frame structures, and the frame and the other three-wheeled vehicle structures, thereby improving the comprehensiveness and accuracy of the test.

[0036] In a possible implementation mode, the configuration of the road surface state and the driving parameter is performed, and the plurality of driving conditions is established. Step S310 further includes step S311 of determining the matching electric three-wheeled vehicle of the frame to be tested, and collecting the factory-recommended road environment constraints. Specifically, the factory-recommended road environment information of the electric three-wheeled vehicle matching the frame to be tested is obtained from the user manual, technical specification, or official website provided by the manufacturer, and the obtained road environment information is arranged into structured data, including the road surface type, the maximum slope, the recommended driving speed, and the like. The factory-recommended road environment is the recommended driving road environment of the manufacturer according to the performance and design characteristics of the electric three-wheeled vehicle, to ensure the best performance and safety of the vehicle.

[0037] In step S312, the road flatness parameters are collected based on the factory-recommended road environment constraints. Specifically, the road flatness of the recommended road environment is measured using a road flatness measuring device (such as a laser road profile instrument, a level, etc.). The measured data is processed to calculate the road flatness parameters, such as the international roughness index (IRI), the root mean square deviation (RMS), and the like.

[0038] In step S313, the driving speed constraints of the matching electric three-wheeled vehicle are collected. Specifically, the relevant information is obtained from the factory specification, technical specification, or performance parameter table provided by the manufacturer, and the driving speed constraints of the vehicle under different conditions are determined according to the obtained performance parameters, such as the maximum driving speed, the economic cruising speed, the braking distance, and the like.

[0039] Step S314, constructing 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 in uniform speed, acceleration, deceleration, emergency braking and turning state. Specifically, the dynamics characteristics of the electric tricycle in common driving conditions (such as uniform speed, acceleration, deceleration, emergency braking, turning, etc.) are analyzed, and the key parameters such as speed, acceleration and deceleration in each condition are determined. Combined with the driving speed constraints and the condition analysis, various driving test parameters are constructed, such as the speed value in uniform speed driving, the acceleration curve in acceleration process, the deceleration curve in deceleration process, etc.

[0040] Step S315, extracting one parameter from the various road flatness parameters and the various driving test parameters respectively to combine and generate the multiple driving conditions. Specifically, the method of permutation and combination is used to select one parameter from the road flatness parameters and the driving test parameters respectively to combine and form multiple driving conditions. For example, different road flatness can be combined with uniform speed driving, acceleration driving, deceleration driving, etc. This implementation mode configures the driving conditions according to the recommended road environment and performance parameters of the electric tricycle out of the factory, which is closer to the actual use of the vehicle and improves the accuracy and practicality of the test.

[0041] In a possible implementation mode, the relationship between the road excitation frequency and the overall natural frequency of the frame is tested under the multiple driving conditions, and the first resonance test result is generated, and step S340 further includes step S341, virtually assembling the frame to be tested with other tricycle structures, collecting vibration modeling data under actual conditions for digital twin modeling, and establishing a twin tricycle operation simulation model. Specifically, using computer-aided design (CAD) software, according to the geometric dimensions and assembly relationship of the frame to be tested and other tricycle structures, virtual assembly is performed to form a complete virtual tricycle model. Through the sensor, the vibration data of the tricycle under actual conditions is collected, 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 for parameterization and fine modeling to form a digital twin model that can reflect the dynamic characteristics of the tricycle under actual conditions.

[0042] Step S342, simulate the plurality of driving conditions with the twin tricycle operation simulation model, and record a plurality of road excitation frequencies. Specifically, according to the plurality of driving conditions established in step S310, set the condition parameters in the simulation software, including road flatness, driving speed, acceleration, etc. Run the twin tricycle operation simulation model in the simulation software to simulate the running state of the tricycle under different conditions. Record the data of the road excitation frequency in the simulation process, which reflects the excitation effect of the road on the tricycle under different conditions. Among them, the road excitation frequency refers to the vibration frequency caused by the uneven road.

[0043] Step S343, analyze the influence of the plurality of road excitation frequencies on the overall natural frequency of the vehicle frame, and generate the first resonance test result. Specifically, perform frequency spectrum analysis on the simulated road excitation frequencies to determine their main frequency components. Compare the road excitation frequencies with the overall natural frequency of the vehicle frame to evaluate whether resonance occurs (when the external excitation frequency is close to or equal to the natural frequency of the structure, the vibration amplitude of the structure increases significantly). When resonance occurs, the vibration amplitude of the vehicle frame will increase significantly, which may cause structural damage or performance degradation. According to the results of the resonance evaluation, the first resonance test result is generated, including the frequency, amplitude, etc. of the resonance. This implementation mode improves the accuracy of resonance evaluation through digital twin technology and simulation analysis.

[0044] In one possible implementation, the vibration excitation relationship between any adjacent vehicle frame structures is tested under the plurality of driving conditions, and the resonance analysis between the vehicle frame structures is performed in combination with the M vehicle frame natural frequencies to generate the second resonance test result. Step S350 further includes step S351 of determining the adjacent first vehicle frame structure and the second vehicle frame structure. Specifically, refer to the CAD drawings of the vehicle frame, and according to the assembly relationship and geometric dimensions in the drawings, identify and determine the two adjacent vehicle frame structures in the vehicle frame to be tested, i.e. the first vehicle frame structure and the second vehicle frame structure.

[0045] Step S352, collect the connection characteristics of the assembly connection points between the first vehicle frame structure and the second vehicle frame structure, wherein the connection characteristics include the connection mode and the contact area. Specifically, use a measuring tool or a sensor to record the connection mode adopted by the connection points, i.e. the technical means adopted for connecting the vehicle frame structures, such as welding, riveting, bolt connection, etc., and measure the contact area of the connection points, i.e. the area of the contact between the two vehicle frame structures at the connection points.

[0046] In step S353, vibration coupling analysis is performed 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. Run the finite element analysis software to perform vibration analysis on the frame structure to obtain the vibration coupling relationship between the first frame structure and the second frame structure, i.e. the degree of mutual influence of the two structures during vibration.

[0047] In step S354, the first vibration coupling relationship is used to optimize the twin tricycle operation simulation model. The simulation model after optimization is used to simulate the multiple driving conditions, record the vibration frequencies corresponding to the M frame structures respectively, and compare them with the natural frequencies of the M frame structures to 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 are adjusted according to the vibration coupling relationship, such as connection stiffness, damping, etc. The simulation analysis software is used to perform simulation analysis on the optimized digital twin model under multiple driving conditions, and record the vibration frequencies of the frame structures under different conditions. Compare the simulated vibration frequencies with the natural frequencies of the frame structures to identify the vibration frequency amplification index, i.e. the case where the vibration frequency is close to or equal to the natural frequency, and the index value is higher when the vibration frequency is close to or equal to the natural frequency. According to the vibration frequency amplification index, the second resonance test result is generated, including the frequency, position, amplitude, etc. of the resonance. This implementation mode more accurately describes the interaction between the frame structures by collecting connection characteristic data and performing vibration coupling analysis, thereby improving the accuracy of resonance evaluation.

[0048] For the acquisition of the third resonance test result, the process 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. Similarly, connection characteristic data needs to be collected, vibration coupling analysis needs to be performed, the simulation model needs to be optimized, and simulation analysis needs to be performed under multiple driving conditions. Finally, according to the simulation results, the resonance between the frame and other tricycle structures is identified, and the third resonance test result is generated.

[0049] In step S400, vibration cycle damage analysis is performed on the 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 the assembly defect nodes.

[0050] Specifically, in combination with the resonance test results and the joint performance parameters, vibration cycle damage analysis is performed on each assembled joint, including evaluating the fatigue life and damage accumulation of the joint in a vibration environment. According to the results of the vibration cycle damage analysis, identify and locate those joints that may have defects or higher risks, which are the key factors leading to the overall performance degradation or failure of the frame. Among them, the vibration cycle damage refers to the damage and fatigue caused by cyclic stress in a vibration environment.

[0051] In one possible implementation, the vibration cycle damage analysis of the N assembled joints is performed with the first resonance test result, the second resonance test result, the third resonance test result, and the N joint performance parameters, and the assembled defect nodes are located. Step S400 further includes step S410, which collects N historical vibration cycle damage sequence data sets of the N assembled joints with the first resonance test result, the second resonance test result, the third resonance test result, and the N joint performance parameters as constraints. Specifically, vibration cycle damage sequence data of each assembled joint (N in total) is collected from historical data. These data come from previous test records, simulation results, or monitoring data in actual operation, and each data point contains vibration amplitude, frequency, damage accumulation, and other information of the joint under a specific working condition. The damage data of each joint is arranged in chronological order to form a vibration cycle damage sequence data set. When collecting the historical vibration cycle damage sequence data set, the influence of the resonance test results and the joint performance parameters needs to be considered, and 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.

[0052] Step S420, based on the long short-term memory network, uses the N historical vibration cycle damage sequence data sets as training samples to train N cycle damage analysis models corresponding to the N assembled joints. Specifically, a long short-term memory (LSTM) 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 input into the LSTM model for training. By adjusting the model parameters, the prediction error is minimized to enable the model to accurately predict the vibration cycle damage of the joint. The performance of the model is evaluated using cross-validation and other methods to ensure the generalization ability of the model.

[0053] Step S430: Based on the N cyclic damage analysis models, analyze and obtain the N damage feature time sequences of the N assembly connection points. Specifically, using the trained LSTM model and the vibration test data of the current frame, perform vibration cyclic damage analysis on the N assembly connection points of the current frame under test, and obtain the damage feature time sequence of each connection point. The damage feature time sequence is a feature sequence describing the change of damage accumulation of the connection point over time in vibration cycle.

[0054] Step S440: Based on the time sequence of the N damage features, connection points whose damage features exceed a preset damage threshold and whose cycle duration is less than a preset cycle duration are identified, generating the assembly defect nodes. Specifically, thresholds for damage features and cycle duration are set according to industry standards. The preset damage threshold is a standard value used to determine whether the damage at a connection point is severe. The preset cycle duration is a standard time used to determine whether the rate of damage accumulation at a connection point is too fast. The time sequence of damage features for all connection points is traversed, comparing the damage features of each connection point with the preset threshold, and simultaneously checking whether its cycle duration is less than the preset cycle duration. Connection points that meet the conditions are marked as assembly defect nodes. This implementation method, by collecting and analyzing historical data, can more accurately assess the vibration cycle damage of the frame structure. Machine learning models such as LSTM can automatically learn the characteristics and patterns of connection point damage, reducing the subjectivity and uncertainty of manual judgment, thereby improving the accuracy and reliability of the test.

[0055] Step S500: Generate the frame structure assembly test results based on the assembly defect nodes.

[0056] Specifically, based on the located assembly defect nodes, a frame structure assembly test result is generated. This result includes 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 in the form of a report to relevant personnel (such as designers, manufacturers, test engineers, etc.) so that subsequent repairs, improvements, or decisions can be made based on the test results. This application embodiment uses 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 conducts resonance tests under various driving conditions, uses the resonance test results and connection point performance parameters to perform vibration cyclic damage analysis, and locates assembly defect nodes. Through resonance testing and vibration cyclic damage analysis, the performance of the frame under various driving conditions is accurately reflected, achieving the technical effect of improving test accuracy.

[0057] In the above text, refer to Figure 1 A method for assembling and testing the frame structure of an electric tricycle according to an embodiment of the present invention is described in detail. Next, reference will be made to... Figure 2 This invention describes a frame structure assembly and testing system for an electric tricycle according to an embodiment of the present invention.

[0058] The electric tricycle frame structure assembly test system according to the embodiment of the present application is used to solve the technical problem that the test precision is difficult to guarantee in the prior art, and achieves the technical effect of improving the test precision. The electric tricycle frame structure assembly test system comprises 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.

[0059] The frame structure and assembly connection point acquisition module 10 is used to acquire M frame structures of a frame to be tested and N assembly connection points of 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 point 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, the frame structure, and the frame and other three-wheeled vehicle structures under multiple driving conditions to generate first, second, and third resonance test results. The vibration cycle damage analysis module 40 is used to perform vibration cycle damage analysis on the N assembly connection points by using the first, second, and third resonance test results 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 by using the assembly defect nodes.

[0060] 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 frames are collected, the resonance tests between the frame and the road surface, the frame structure, and the frame and other three-wheeled vehicle structures are respectively performed under multiple driving conditions to generate the first resonance test result, the second resonance test result, and the third resonance test result. The resonance test module 30 can further include: a multiple driving condition establishing unit for performing configuration of road surface states and driving parameters to establish the multiple driving conditions; an inherent frequency determining unit for fitting the overall frame inherent frequency and the M frame structure inherent frequencies based on the M frame design parameters to determine the inherent frequencies of other three-wheeled vehicle structures; a first resonance test result generating unit for testing the relationship between the road surface excitation frequency and the overall frame inherent frequency under the multiple driving conditions to generate the first resonance test result; a second resonance test result generating unit for testing the vibration excitation relationship between any adjacent frame structures under the multiple driving conditions, and performing resonance analysis between the frame structures in combination with the M frame structure inherent frequencies to generate the second resonance test result; and a third resonance test result generating unit for testing the vibration excitation relationship between the frame and other three-wheeled vehicle structures under the multiple driving conditions, and performing resonance analysis between the frame structures in combination with the overall frame inherent frequency and the inherent frequencies of other three-wheeled vehicle structures to generate the third resonance test result.

[0061] The multiple driving condition establishing unit can further include: a factory recommended road environment constraint collecting sub-unit for determining a matching electric three-wheeled vehicle of the frame to be tested and collecting factory recommended road environment constraints; a road flatness parameter collecting sub-unit for collecting each road flatness parameter based on the factory recommended road environment constraints; a driving speed constraint collecting sub-unit for collecting driving speed constraints of the matching electric three-wheeled vehicle; a driving test parameter constructing sub-unit for constructing each driving test parameter based on the driving speed constraints, wherein the each driving test parameter at least includes parameters of the matching electric three-wheeled vehicle under uniform speed, acceleration, deceleration, sudden braking, and turning states; and a multiple driving condition generating sub-unit for combining one parameter extracted from the each road flatness parameter and the each driving test parameter to generate the multiple driving conditions.

[0062] The first resonance test result is generated by testing the relationship between the road excitation frequency and the inherent frequency of the whole frame under the plurality of driving conditions, and the first resonance test result generation unit can further include: a twin tricycle operation simulation model establishment subunit for virtually assembling the frame to be tested with other tricycle structures, collecting vibration modeling data under actual conditions for digital twin modeling, and establishing a twin tricycle operation simulation model; a simulation subunit for simulating the plurality of driving conditions based on the twin tricycle operation simulation model, and recording a plurality of road excitation frequencies; and a first resonance test result generation subunit for analyzing the influence of the plurality of road excitation frequencies on the inherent frequency of the whole frame, and generating the first resonance test result.

[0063] The second resonance test result is generated by testing the vibration excitation relationship between any adjacent frame structures under the plurality of driving conditions, and performing resonance analysis between the frame structures in combination with the inherent frequencies of the M frame structures, and the second resonance test result generation unit can further include: an adjacent frame structure determination subunit for determining adjacent first and second frame structures; a connection feature acquisition subunit for acquiring the connection features of the assembly connection points between the first and second frame structures, wherein the connection features include the connection mode and the contact area; a vibration coupling analysis subunit for performing vibration coupling analysis based on the connection features of the assembly connection points to generate a first vibration coupling relationship; and a second resonance test result generation subunit for optimizing the twin tricycle operation simulation model based on the first vibration coupling relationship, simulating the plurality of driving conditions through the optimized simulation model, recording the vibration frequencies corresponding to the M frame structures respectively, and comparing the vibration frequencies with the inherent frequencies of the M frame structures to identify a vibration frequency amplification index, and generating the second resonance test result.

[0064] In the following, the specific configuration of the vibration cycle damage analysis module 40 will be described in detail. As described above, the vibration cycle damage analysis of the N assembled connecting points is performed based on the first resonance test result, the second resonance test result, the third resonance test result and the N connecting point performance parameters, the vibration cycle damage analysis module 40 can further comprise: a historical vibration cycle damage sequence dataset collection unit for collecting N historical vibration cycle damage sequence datasets of the N assembled connecting points as constraints based on the first resonance test result, the second resonance test result, the third resonance test result and the N connecting point performance parameters; a cycle damage analysis model training unit for training N cycle damage analysis models corresponding to the N assembled connecting points based on a long short-term memory network, and using the N historical vibration cycle damage sequence datasets as training samples; a damage feature time sequence acquisition unit for analyzing and acquiring N damage feature time sequences of the N assembled connecting points based on the N cycle damage analysis models; and an assembled defect node generation unit for generating the assembled defect node based on the N damage feature time sequences, identifying the connecting points whose damage features exceed a preset damage threshold and whose cycle lengths are less than a preset cycle length.

[0065] In the following, the specific configuration of the connection performance analysis module 20 will be described in detail. As described above, the connection performance analysis of the N assembled connecting points is performed to generate N connecting point performance parameters, the connection performance analysis module 20 can further comprise: a connection feature acquisition unit for acquiring N connection features of the N assembled connecting points; and a connecting point performance parameter generation unit for generating the N connecting point performance parameters based on the N connection features, identifying the strength, stiffness and damping characteristics of the connecting points based on a connection performance comparison library, wherein the performance comparison library comprises a plurality of performance comparison samples, and any one performance comparison sample comprises a connection feature sample and identification information comprising the strength, stiffness and damping characteristics of the connecting points.

[0066] The electric tricycle frame structure assembly test system provided by the embodiment of the present application can perform the electric tricycle frame structure assembly test method provided by any embodiment of the present application, and has the corresponding function modules and beneficial effects of the execution method.

[0067] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, however, any number of different modules can be used and run on the user terminal and / or server, and each unit and module included is only divided according to the functional logic, but is not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of each functional unit are only for the convenience of mutual differentiation, and do not limit the protection scope of the present application.

[0068] The foregoing DETAILED DESCRIPTION, including the above section titled "Detailed Description," is not to be taken as limiting the scope of the application. Various modifications, combinations, and equivalents can be apparent to those skilled in the art and can be made once the nature of the application is understood. Any modification, combination, or equivalent, which falls within the principles and the scope of the present application, is intended to be included in the present application. In some instances, the actions or steps can be performed in different order from those described herein, and still achieve desirable results. Additionally, the process depicted in the figures can not necessarily require the particular order shown or sequential order to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.

Claims

1. A method of assembling and testing a frame structure of an electrically powered tricycle, characterized by, The method comprises the following steps: Obtain M frame structures of a to-be-tested frame, and N assembly connection points of assembling the M frame structures, wherein M and N are integers greater than or equal to 1; Perform connection point connection performance analysis on the N assembly connection points to generate N connection point performance parameters; Collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road, the frame structure, and the frame and other three-wheeled vehicle structures under multiple driving conditions to generate first, second, and third resonance test results; Perform vibration cycle damage analysis on the N assembly connection points based on the first, second, and third resonance test results and the N connection point performance parameters to locate assembly defect nodes; Generate a frame structure assembly test result based on the assembly defect nodes; Collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road, the frame structure, and the frame and other three-wheeled vehicle structures under multiple driving conditions to generate first, second, and third resonance test results, comprising: Perform road state and driving parameter configuration to establish the multiple driving conditions; Fit the overall frame natural frequency and the M frame structure natural frequencies based on the M frame design parameters; Determine the natural frequency of other three-wheeled vehicle structures; Test the relationship between the road excitation frequency and the overall frame natural frequency under the multiple driving conditions to generate the first resonance test result; 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; Test the vibration excitation relationship between the frame and other three-wheeled vehicle structures under the multiple driving conditions, and perform resonance analysis between the frame structures in combination with the overall frame natural frequency and the natural frequency of other three-wheeled vehicle structures to generate the third resonance test result; Perform road state and driving parameter configuration to establish the multiple driving conditions, comprising: Determine a matching electric three-wheeled vehicle of the to-be-tested frame, and collect factory-recommended road environment constraints; Collect each road flatness parameter based on the factory-recommended road environment constraints; Collect driving speed constraints of the matching electric three-wheeled vehicle; Construct each driving test parameter based on the driving speed constraints, wherein the each driving test parameter at least includes parameters of the matching electric three-wheeled vehicle under uniform speed, acceleration, deceleration, sudden braking, and turning states; Combine one parameter extracted from the each road flatness parameter and the each driving test parameter to generate the multiple driving conditions; Test the relationship between the road excitation frequency and the overall frame natural frequency under the multiple driving conditions to generate the first resonance test result, comprising: Perform virtual assembly of the to-be-tested frame and other three-wheeled vehicle structures, collect vibration modeling data under actual working conditions to perform digital twin modeling, and establish a twin three-wheeled vehicle operation simulation model; simulate the multiple driving conditions by using the twin tricycle operation simulation model, and record multiple road excitation frequencies; analyze the influence of the multiple road excitation frequencies on the overall natural frequency of the vehicle frame, and generate the first resonance test result.

2. The method of claim 1, wherein the method further comprises: determining whether the vehicle frame structure is assembled correctly based on the comparison result. test the vibration excitation relationship between any adjacent vehicle frame structures under the multiple driving conditions, and perform resonance analysis between the vehicle frame structures in combination with the M vehicle frame structure natural frequencies to generate the second resonance test result, including: determining adjacent first and second vehicle frame structures; collecting connection characteristics of an assembly connection point between the first and second vehicle frame structures, where the connection characteristics include a connection mode and a contact area; performing vibration coupling analysis based on the connection characteristics of the assembly connection point to generate a first vibration coupling relationship; optimizing the twin tricycle operation simulation model by using the first vibration coupling relationship, simulating the multiple driving conditions by using the optimized simulation model, recording M vehicle frame structure corresponding vibration frequencies, and comparing the vibration frequencies with the M vehicle frame structure natural frequencies to identify a vibration frequency amplification index and generate the second resonance test result.

3. The method of claim 1, wherein the method further comprises: determining whether the vehicle frame structure is assembled correctly based on the comparison result. performing vibration cycle damage analysis of N assembly connection points by 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, including: collecting N historical vibration cycle damage sequence data sets of N assembly connection points as constraints by using the first resonance test result, the second resonance test result, the third resonance test result, and the N connection point performance parameters; training N cycle damage analysis models corresponding to the N assembly connection points by using the N historical vibration cycle damage sequence data sets as training samples based on a long short-term memory network; analyzing and obtaining N damage feature time sequences of the N assembly connection points based on the N cycle damage analysis models; identifying a connection point whose damage feature exceeds a preset damage threshold and whose cycle length is less than a preset cycle length based on the N damage feature time sequences to generate the assembly defect nodes.

4. The method of claim 1, wherein the method further comprises: determining whether the vehicle frame structure is assembled correctly based on the comparison result. performing connection performance analysis of the N assembly connection points to generate N connection point performance parameters, including: obtaining N connection characteristics of the N assembly connection points; identifying connection point strength, stiffness, and damping characteristics based on the N connection characteristics by using a connection performance comparison library to generate the N connection point performance parameters, where the performance comparison library includes multiple groups of performance comparison samples, and any group of performance comparison samples includes a connection characteristic sample and identification information including the connection point strength, stiffness, and damping characteristics.

5. A test system for assembling a frame structure of an electrically powered tricycle, characterized by The system is used to implement the vehicle frame structure assembly test method of any one of claims 1-4, and the system includes: a vehicle frame structure and assembly connection point acquisition module configured to acquire M vehicle frame structures of a vehicle frame to be tested and N assembly connection points for assembling the M vehicle frame structures, where M and N are integers greater than or equal to 1. The connection performance analysis module is configured to analyze the connection performance of the N assembly connection points to generate N connection point performance parameters. The resonance test module is configured to collect M frame design parameters of the M frame structures, and perform resonance tests between the frame and the road, the frame structure, and the frame and other tricycles under various driving conditions to generate first, second, and third resonance test results. The vibration cycle damage analysis module is configured to perform vibration cycle damage analysis on the N assembly connection points based on the first, second, and third resonance test results and the N connection point performance parameters to locate assembly defect nodes. The frame structure assembly test result generation module is configured to generate a frame structure assembly test result based on the assembly defect nodes.

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