An axle load and its load state detection control system

Abstract

The application relates to the technical field of automobile part detection, and particularly discloses an axle load and load state detection control system, which acquires a second displacement curve similar to a preset first displacement curve on a test axle in a test process, then repeatedly tests, and in the test process, the second displacement curve is observed in real time until the second displacement curve and the first displacement curve have a large difference, so that the fatigue limit of the test axle under repeated instantaneous loads in a preset state is acquired, which can be used as a parameter supplement in the test process of the axle and can comprehensively acquire the detection structure of the axle. In addition, the test process provided by the embodiment directly compares the data acquired by the state monitoring module, so that the error influence caused by the measurement accuracy in the data conversion and acquisition process is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of automotive parts testing technology, specifically to a vehicle axle load and its load status detection and control system. Background Technology

[0002] The axle is one of the essential key components of a vehicle. During vehicle operation, especially during sudden acceleration or emergency braking, the various components within the axle bear significant impact loads. To ensure the normal operation of the axle, in addition to certain technical requirements for its internal mechanisms and parts, there are also special requirements for assembly precision. However, as the vehicle's mileage increases, the technical condition of the axle's components gradually deteriorates, leading to various malfunctions. Common axle malfunctions include noise and overheating.

[0003] Axle load testing is one method of axle performance testing, which can detect the axle's limit state. Its principle lies in reflecting the load state through the deformation of key points under a certain load. For example, in the Chinese invention with publication number CN115575137 A, a test electric cylinder is installed at the bottom of a frame. The test electric cylinder presses down on the axle, thereby testing its load capacity. Ordinary pressure testing can test the axle's limit load. The limit load data obtained is based on the deformation of key points. This means that the final experimental results are greatly affected by the accuracy of the deformation detection equipment. Furthermore, in actual use, axles are not subjected to limit loads for extended periods; instead, they are frequently subjected to instantaneous loads caused by fluctuations during vehicle movement. Therefore, a single limit load test, affected by the accuracy of the deformation detection equipment, cannot fully reflect the axle's strength state.

[0004] To overcome the problem that experimental results are affected by the accuracy of deformation detection equipment and that the strength detection dimension of the vehicle axle is too singular, this invention proposes a vehicle axle load and its load state detection and control system. Summary of the Invention

[0005] The purpose of this invention is to provide a vehicle axle load and its load status detection and control system, solving the following technical problems:

[0006] How can we overcome the problem of experimental results being affected by the accuracy of deformation detection equipment, while also addressing the issue of overly simplistic strength testing dimensions for vehicle axles?

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A vehicle axle load and its load state detection and control system, comprising:

[0009] The condition monitoring module is used to continuously acquire deformation data of multiple key points of the axle;

[0010] Load module, which is used to apply loads to the axle;

[0011] The pre-analysis module compares the first displacement curve of the pre-set key point deformation with the second displacement curve generated by the corresponding key point during the detection process by applying load, and generates a comparison result.

[0012] The control module controls the load module to repeatedly apply loads to the axle based on the comparison results.

[0013] The state analysis module compares the second displacement curve generated in each complete process of repeatedly applying load to the axle with the preset first displacement curve to generate the detection result.

[0014] The above technical solution involves adjusting the applied load and the incremental load from zero to obtain a second displacement curve similar to the preset first displacement curve on the test axle during the test. The test is then repeated, and the second displacement curve is observed in real time until a significant difference appears between the second and first displacement curves. This allows the fatigue limit of the test axle under repeated instantaneous loads in a preset state to be obtained. This can serve as a parameter supplement in the axle testing process, enabling a more comprehensive understanding of the axle's testing structure. Furthermore, the testing process provided in this embodiment directly compares the data obtained by the condition monitoring module, thereby greatly reducing the impact of errors caused by measurement accuracy during data conversion and acquisition.

[0015] As a further technical solution of the present invention: the method for obtaining the key points includes:

[0016] Three-dimensional modeling and finite element analysis of the vehicle axle were performed.

[0017] Based on the results of finite element analysis, the regions on the axle where concentrated stress occurs under applied load are obtained.

[0018] Select points symmetrical about the axle center from the region where concentrated stress occurs as key points.

[0019] As a further technical solution of the present invention: the comparison process of the pre-analysis module includes:

[0020] Place the first displacement curve and the second displacement curve in the same rectangular coordinate system, and make the starting points of the first displacement curve and the second displacement curve coincide.

[0021] Obtain the coordinates of the corresponding peak points of the first and second displacement curves and compare them;

[0022] The comparison results include the overlap between the peak point of the second displacement curve and the peak point of the first displacement curve, and the overlap between the peak point of the second displacement curve and the peak point of the first displacement curve. The overlap area is a vertical straight line area centered on the peak point of the first displacement curve.

[0023] As a further technical solution of the present invention: the process of controlling the load module to repeatedly apply load to the axle according to the comparison results includes:

[0024] If the comparison result shows that the peak point of the second displacement curve exceeds the overlapping area of ​​the peak point of the first displacement curve, then the difference in the horizontal coordinate is obtained, and the time difference between the time taken for the first displacement curve to reach the peak from the starting point and the time taken for the second displacement curve to reach the peak from the starting point is obtained based on the difference in the horizontal coordinate.

[0025] Based on the time difference, while maintaining a uniform increase in load, the magnitude of the load increment is adjusted to eliminate the time difference;

[0026] After eliminating the time difference, the load applied to the second displacement curve during the test is adjusted according to the load applied to the first displacement curve, so that the peak point of the second displacement curve falls into the overlapping area of ​​the peak point of the first displacement curve.

[0027] As a further technical solution of the present invention: the process of obtaining the load applied to the second displacement curve during the test by adjusting the load applied according to the first displacement curve includes:

[0028] According to the formula:

[0029] as well as

[0030]

[0031] Obtain Correction Force by The new load amount is obtained during the process of obtaining the second displacement curve for the second correction amount;

[0032] in For the first correction, y1 is the ordinate of the peak point of the first displacement curve, y2 is the ordinate of the peak point of the second displacement curve obtained during the test under the same load as that used to obtain the first displacement curve, and y3 is... The ordinate of the peak point of the second displacement curve obtained under the first correction condition, F1 is the load magnitude of the first displacement curve, and δ is the preset scaling factor;

[0033] Then determine the load amount. If the peak point of the second displacement curve obtained under the new load falls into the overlapping area, continue to obtain the new load using formula (1) and formula (2) until the peak point of the second displacement curve obtained under the new load falls into the overlapping area.

[0034] The above technical solution provides a specific scheme for adjusting the load on the second displacement curve. The purpose of this scheme is to perform a round of adjustment using formulas (1) and (2), thereby greatly reducing the number of adjustments compared to step-by-step adjustments. Specifically, a first correction is performed, and the correction force is obtained based on the result of the first correction. Obtain Correction Force During the process, a second correction is made based on the first correction. The two corrections constitute one round of correction. The second correction is to make the peak point closer to the overlapping area.

[0035] As a further technical solution of the present invention, the process of obtaining the second displacement curve also includes:

[0036] Obtain the similarity R between the second displacement curve and the first displacement curve under the new load, and compare the similarity R with the preset value R0;

[0037] If the similarity R ≥ R0, then the similarity is deemed insufficient. Then, the area S between the second displacement curve and the first displacement curve is obtained, and the load is controlled so that the peak point of the second displacement curve changes within the overlapping area so that the area is minimized.

[0038] If the similarity R < R0, then the similarity is considered sufficient.

[0039] The above technical solution uses the similarity of the curves as a benchmark. When the similarity is insufficient, the load is controlled to make the peak point of the second displacement curve change within the overlapping area so that the area is minimized. This results in a higher similarity between the curves, making the test process more representative of the fatigue limit under the preset state, and facilitating the laboratory to obtain more accurate test results.

[0040] As a further technical solution of the present invention: the comparison process of the state analysis module includes:

[0041] The new load and load increment are applied uniformly and repeatedly to the axle during the test.

[0042] Obtain the second displacement curve generated during the repetition process, and obtain the data generated during the most recent N repetitions;

[0043] According to the formula:

[0044]

[0045] Obtain the deviation P, where Si Si is the area between the second displacement curve and the first displacement curve in the i-th repetition during the most recent N repetitions; S0 is the average area between the second displacement curve and the first displacement curve in the n repetitions at the beginning of the repetition process.

[0046] As a further technical solution of the present invention: the deviation P is compared with a preset threshold P0;

[0047] If P≥P0, then the test axle has reached its limit, and the current loop count is recorded.

[0048] If P < P0, then it is determined that the test axle has not reached its limit, and the loop continues.

[0049] As a further technical solution of the present invention: during the repeated application of load to the axle, the time interval between two adjacent repeated actions is the same, and the time interval is sufficient for the heat generated during the deformation process to be transferred outward.

[0050] The beneficial effects of this invention are:

[0051] (1) The present invention adjusts the applied load and the incremental load applied from zero, and obtains a second displacement curve similar to the preset first displacement curve on the test axle during the test process. Then the test is repeated. During the test, the second displacement curve is observed in real time until the second displacement curve and the first displacement curve have a large difference. In this way, the fatigue limit of the test axle under repeated instantaneous load in the preset state can be obtained. It can be used as a parameter supplement in the axle test process, and can obtain the test structure of the axle more comprehensively. In addition, the test process provided in this embodiment is to directly compare the data obtained by the condition monitoring module, thereby greatly reducing the error caused by the measurement accuracy during the data conversion and acquisition process.

[0052] (2) This invention uses formulas (1) and (2) to make a round of adjustments, thereby greatly reducing the number of adjustments compared to step-by-step adjustments. The first correction is performed first, and the correction force is obtained based on the result of the first correction. Obtain Correction Force During the process, a second correction is made based on the first correction. The two corrections constitute one round of correction. The second correction is to make the peak point closer to the overlapping area.

[0053] (3) In the case of insufficient similarity, the present invention controls the load to make the peak point of the second displacement curve change in the overlapping area so that the area is minimized, thereby making the similarity between the curves higher, making the test process more representative of the fatigue limit under the preset state, and making it easier for the laboratory to obtain more accurate test results. Attached Figure Description

[0054] The invention will now be further described with reference to the accompanying drawings.

[0055] Figure 1 This is a logic diagram of the modules in this invention. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Please see Figure 1 As shown, in one embodiment, a vehicle axle load and its load state detection and control system is provided, comprising:

[0058] The condition monitoring module, which can be a patch inspection or optical inspection, is used to continuously acquire deformation data of multiple key points of the axle;

[0059] The load module is used to apply loads to the axle. The load module is preferably a hydraulic cylinder for easy control.

[0060] The pre-analysis module compares the first displacement curve of the pre-set key point deformation with the second displacement curve generated by the corresponding key point during the detection process by applying load, and generates a comparison result.

[0061] The control module controls the load module to repeatedly apply loads to the axle based on the comparison results.

[0062] The state analysis module compares the second displacement curve generated in each complete process of repeatedly applying load to the axle with the preset first displacement curve to generate the detection result.

[0063] Through the above technical solution: In this embodiment, by adjusting the applied load and the incremental load applied from zero, a second displacement curve similar to the preset first displacement curve is obtained on the test axle during the test process. The test is then repeated, and the second displacement curve is observed in real time during the test until a large difference appears between the second displacement curve and the first displacement curve. This allows the fatigue limit of the test axle under repeated instantaneous loads in a preset state to be obtained. This can serve as a parameter supplement in the axle test process, enabling a more comprehensive acquisition of the axle's test structure. Furthermore, the test process provided in this embodiment directly compares the data acquired by the condition monitoring module, thereby greatly reducing the impact of errors caused by measurement accuracy during data conversion and acquisition.

[0064] Key points can be obtained through the following methods:

[0065] When performing 3D modeling and finite element analysis on the vehicle axle, it is important to note that, depending on the required computational accuracy and the scale of the model, it is not necessary to perform a complete and accurate model of the vehicle axle. Therefore, components that have little impact on the overall stiffness and mass matrix of the structure can be simplified, so that the finite element model can reflect the main characteristics of the structure and minimize the solution time.

[0066] Based on the results of finite element analysis, the regions on the axle where concentrated stress occurs under applied load are obtained.

[0067] Select points that are symmetrical with respect to the center of the axle from the region where concentrated stress is generated. It should be noted that positional symmetry means that the two symmetrical key points are both centrally symmetrical and axially symmetrical.

[0068] The comparison process of the pre-analysis module includes:

[0069] Place the first displacement curve and the second displacement curve in the same rectangular coordinate system, and make the starting points of the first displacement curve and the second displacement curve coincide.

[0070] Obtain the coordinates of the corresponding peak points of the first and second displacement curves and compare them;

[0071] The comparison results include the overlap between the peak point of the second displacement curve and the peak point of the first displacement curve, and the overlap between the peak point of the second displacement curve and the peak point of the first displacement curve. The overlap area is a vertical straight line area centered on the peak point of the first displacement curve.

[0072] The process of controlling the load module to repeatedly apply loads to the axle based on the comparison results includes:

[0073] If the comparison result shows that the peak point of the second displacement curve exceeds the overlapping area of ​​the peak point of the first displacement curve, then the difference in the horizontal coordinate is obtained, and the time difference between the time taken for the first displacement curve to reach the peak from the starting point and the time taken for the second displacement curve to reach the peak from the starting point is obtained based on the difference in the horizontal coordinate.

[0074] Based on the time difference, while maintaining a uniform increase in load, the magnitude of the load increment is adjusted to eliminate the time difference;

[0075] After eliminating the time difference, the load applied to the second displacement curve during the test is adjusted according to the load applied to the first displacement curve, so that the peak point of the second displacement curve falls into the overlapping area of ​​the peak point of the first displacement curve.

[0076] The process of adjusting the load applied to the second displacement curve based on the load applied to the first displacement curve during the test includes:

[0077] According to the formula:

[0078] as well as

[0079]

[0080] Obtain Correction Force by The new load amount is obtained during the process of obtaining the second displacement curve for the second correction amount;

[0081] in For the first correction, y1 is the ordinate of the peak point of the first displacement curve, y2 is the ordinate of the peak point of the second displacement curve obtained during the test under the same load as that used to obtain the first displacement curve, and y3 is... The ordinate of the peak point of the second displacement curve obtained under the first correction condition, F1 is the load magnitude of the first displacement curve, and δ is the preset proportional coefficient, which is an empirical constant and is determined based on the results of the first and second corrections.

[0082] Then determine the load amount. If the peak point of the second displacement curve obtained under the new load falls into the overlapping area, continue to obtain the new load using formula (1) and formula (2) until the peak point of the second displacement curve obtained under the new load falls into the overlapping area.

[0083] Through the above technical solution: In this embodiment, a specific scheme for adjusting the load amount of the second displacement curve is provided. The purpose of this scheme is to perform a round of adjustment using formulas (1) and (2), thereby greatly reducing the number of adjustments compared to step-by-step adjustments. Specifically, a first correction is performed first, and the correction force is obtained based on the result of the first correction. Obtain Correction Force During the process, a second correction is made based on the first correction. The two corrections constitute one round of correction. The second correction is to make the peak point closer to the overlapping area.

[0084] The process of obtaining the second displacement curve also includes:

[0085] Obtain the similarity R between the second displacement curve and the first displacement curve under the new load, and compare the similarity R with the preset value R0. The calculation method of the curve similarity is the existing technology, preferably the root mean square algorithm, and its specific process will not be elaborated.

[0086] If the similarity R ≥ R0, then the similarity is deemed insufficient. Then, the area S between the second displacement curve and the first displacement curve is obtained, and the load is controlled so that the peak point of the second displacement curve changes within the overlapping area so that the area is minimized.

[0087] If the similarity R < R0, then the similarity is considered sufficient.

[0088] Through the above technical solution: In this embodiment, the similarity of the curves is used as the benchmark. When the similarity is insufficient, the load is controlled to make the peak point of the second displacement curve change within the overlapping area to obtain the minimum area, thereby increasing the similarity between the curves. This makes the test process more representative of the fatigue limit under the preset state, and facilitates obtaining more accurate test results in the laboratory.

[0089] The comparison process of the status analysis module includes:

[0090] The new load and load increment are applied uniformly and repeatedly to the axle during the test.

[0091] Obtain the second displacement curve generated during the repetition process, and obtain the data generated during the most recent N repetitions;

[0092] According to the formula:

[0093]

[0094] Obtain the deviation P, where S i Si is the area between the second displacement curve and the first displacement curve in the i-th repetition during the most recent N repetitions; S0 is the average area between the second displacement curve and the first displacement curve in the n repetitions at the beginning of the repetition process.

[0095] Compare the deviation P with the preset threshold P0;

[0096] If P≥P0, then the test axle has reached its limit, and the current loop count is recorded.

[0097] If P < P0, then it is determined that the test axle has not reached its limit, and the loop continues.

[0098] During the repeated application of load to the axle, the time interval between two adjacent repeated actions is the same, and the time interval is sufficient for the heat generated during the deformation process to be transferred outward.

[0099] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. An axle load and its load state detection control system characterized by, Comprise: State monitoring module for continuous acquisition of axle multiple key point deformation data; Load module, for applying load to the axle; Pre-analysis module, comparing the first displacement curve of the preset key point deformation with the second displacement curve generated by the corresponding key point during the loading process to generate a comparison result; Control module, according to the comparison result, control the load module to repeat the process of applying load to the axle; State analysis module, comparing the second displacement curve generated in each complete process of the repeated load application process to the first displacement curve to generate a detection result; According to the comparison result, control the load module to repeat the process of applying load to the axle, comprising: If the comparison result is that the peak point of the second displacement curve exceeds the overlapping area of the peak point of the first displacement curve, obtain the difference of the abscissa, and obtain the time difference between the time taken by the first displacement curve to reach the peak from the starting point and the time taken by the second displacement curve to reach the peak from the starting point according to the abscissa difference; According to the time difference, adjust the increment size of the load on the basis of maintaining uniform load increase to eliminate the time difference; After eliminating the time difference, adjust the load applied to the second displacement curve during the test process according to the load applied to the first displacement curve, so that the peak point of the second displacement curve falls within the overlapping area of the peak point of the first displacement curve; The process of adjusting the load applied to the second displacement curve during the test process according to the load applied to the first displacement curve, comprising: According to the formula: (1), and (2)； acquiring a correction force to acquire a new load amount in the second displacement curve process for the second correction amount wherein is a first correction amount, is a vertical coordinate of a peak point of the first displacement curve, is a vertical coordinate of a peak point of a second displacement curve obtained under the condition that the same load as that for obtaining the first displacement curve is applied during the test, is a second correction amount, is a vertical coordinate of a peak point of the second displacement curve obtained under the condition that the first correction is performed, is a load size at which the first displacement curve is obtained, is a preset proportional coefficient; If the load amount is + whether the peak point of the second displacement curve obtained under the new load amount falls into the overlapping area. If not, new load amount is obtained by using formula (1) and formula (2) until the peak point of the second displacement curve obtained under the new load amount falls into the overlapping area.

2. The axle load and its load state detection control system according to claim 1, characterized by, The acquisition method of the key point comprises: Three-dimensional modeling of the axle and finite element analysis, it should be noted that, according to the requirements of calculation accuracy and modeling scale, it is not necessary to model the axle completely and accurately, therefore, the components that have little effect on the overall stiffness and mass matrix of the structure can be simplified, so that the finite element model can reflect the main characteristics of the structure and minimize the solving time; According to the results of finite element analysis, the area of the axle where concentrated stress is generated under the state of applying load is obtained; From the area where concentrated stress is generated, points symmetric to the center position of the axle are selected as key points, it should be noted that, the position symmetry refers to the symmetry of the two key points, both central symmetry and axial symmetry.

3. The axle load and its load state detection control system according to claim 1, characterized by, The comparison process of the pre-analysis module comprises: Place the first displacement curve and the second displacement curve in the same rectangular coordinate system, and make the starting points of the first displacement curve and the second displacement curve coincide; Obtain the coordinates of the corresponding peak points of the first displacement curve and the second displacement curve and compare them; The comparison result includes that the peak point of the second displacement curve falls within the overlapping area of the peak point of the first displacement curve, and the peak point of the second displacement curve exceeds the overlapping area of the peak point of the first displacement curve, wherein the overlapping area is a vertical straight line area centered on the peak point of the first displacement curve.

4. The axle load and its load state detecting control system according to claim 1, characterized by The process of obtaining the second displacement curve further comprises: Obtain the similarity between the second displacement curve under the new load and the first displacement curve Compare the similarity With a preset value ​ if the similarity degree is insufficient, then the area between the second displacement curve and the first displacement curve is obtained , the load amount is controlled so that the peak point of the second displacement curve changes within the overlapping area so that the area obtains a minimum value; if similarity then determine that the similarity is sufficient.

5. The axle load and its load state detecting control system according to claim 4, characterized by The comparison process of the state analysis module comprises: Apply load to the axle uniformly and repeatedly in the test process with new load and load increment; acquiring a second displacement curve generated during a repeat procedure, acquiring data generated during a most recent repeat procedure; According to the formula: (3)； acquiring a deviation amount wherein is the most recent is the area of the second displacement curve during the n-th repetition process and the first displacement curve; is the area of the second displacement curve during the n-th repetition process and the first displacement curve; is the mean value of the area of the second displacement curve during the n-th repetition process and the first displacement curve at the beginning of the repetition process is the mean value of the area of the second displacement curve during the n-th repetition process and the first displacement curve at the beginning of the repetition process 6. The axle load and its load state detecting control system according to claim 5, characterized by amount of deviation compared with a preset threshold comparison; If then determine that the test axle has reached the limit, record the current cycle number; If then the test axle is judged not to have reached the limit and the loop continues.

7. The axle load and its load state detecting control system according to claim 1, characterized by, The time interval of two adjacent repetitive actions is same and the time interval is enough for heat generated in the deformation process to transfer outward.

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