A brake assembly rattle detection method and apparatus

Abstract

The application discloses a brake assembly runout detection method and device, the method comprising: obtaining a first runout curve of the brake assembly in a reference assembly state; rotating the brake disc relative to the hub by a preset angle and assembling under the same assembly pretightening force to obtain a second runout curve; changing the assembly pretightening force while keeping the relative angle between the brake disc and the hub unchanged to obtain a third runout curve; performing angle coordinate translation on the second runout curve, and separating a hub eccentric error curve based on the difference between the translated second runout curve and the first runout curve; and determining an assembly pretightening deformation component based on the difference between the first runout curve and the third runout curve, and further separating a brake disc shape error curve. The technical scheme of the application realizes quantitative separation of different error sources in the brake assembly by combining geometric repositioning with assembly pretightening variables, and improves the interpretability and diagnosis pertinence of the runout detection result.

Description

Technical Field

[0001] The field of brake assembly testing and manufacturing quality control technology, particularly a brake assembly runout testing method, device, equipment, and storage medium. Background Technology

[0002] Brake assembly turning typically refers to the process of finishing or repairing the working surface of the brake disc on a specialized lathe or in-line machining equipment after the brake disc, wheel hub, and other components have been assembled with bearings, wheel rims, etc. By turning the assembly, the end face and flatness of the brake disc can be corrected as much as possible with the wheel hub axis as a reference, reducing the deviation of the brake disc from the actual axis of rotation, thereby reducing torque fluctuations and pedal vibration during braking. Since brakes are affected by various factors during operation, such as assembly errors, thermal deformation, and wear, runout testing needs to be performed simultaneously after assembly turning to confirm that the end face runout and radial runout are controlled within the allowable range, ensuring the stability and comfort of the vehicle during braking.

[0003] In existing technologies, brake assembly runout detection mainly relies on geometric measurements. A typical approach involves mounting the brake assembly on a testing fixture or turning equipment, rotating it via a motor or manually, and placing dial indicators, inductive displacement sensors, laser probes, etc., at the working radius of the brake disc to collect displacement changes over one or more revolutions. The difference between the maximum and minimum values ​​is then used as the evaluation result for end-face or radial runout. Some production lines have online inspection stations after assembly to perform full or random inspections of the wheel-side assembly or brake assembly, comparing the runout value with a preset threshold to determine pass or fail. Other solutions, under vehicle-state conditions, indirectly assess the brake disc runout level using displacement, pressure, and vibration sensors inside or near the caliper. However, ultimately, most still rely on a single numerical value or simple waveform characteristics as the evaluation basis.

[0004] While the aforementioned technical approach to brake runout detection can reflect the magnitude of brake geometric errors to some extent, it generally suffers from limitations in information dimension and diagnostic capabilities. The detection results typically only provide a composite runout value, making it difficult to distinguish whether the runout is caused by a combination of factors such as brake disc machining errors, wheel hub and bearing eccentricity, or deformation due to assembly preload. Engineers often have to rely on experience for repeated trial and error during process adjustments and fault analysis. Therefore, how to make runout detection results more clearly characterize the influence relationships of various error factors in the assembly, thereby improving the relevance and interpretability of runout detection, has become an urgent problem to be solved. Summary of the Invention

[0005] This application provides a brake assembly runout detection method, aiming to solve the technical problems of existing brake assembly runout detection methods that can only obtain a single composite runout value and have difficulty distinguishing different error sources such as brake disc shape error, wheel hub eccentricity error, and assembly preload deformation.

[0006] This invention is implemented as follows: a method for detecting brake assembly runout, comprising:

[0007] The first runout curve of the brake assembly is obtained under the reference assembly condition;

[0008] After rotating the brake disc relative to the wheel hub by a preset angle, assemble it with the same assembly preload force as the reference assembly state, and obtain the second runout curve of the brake assembly.

[0009] While maintaining the same relative angular position between the brake disc and the wheel hub as the reference assembly state, the assembly preload is changed to obtain the third runout curve of the brake assembly.

[0010] The first runout curve, the second runout curve, and the third runout curve all characterize the distribution of the positional deviation of the brake disc working surface relative to the rotation axis with the rotation angle.

[0011] The second bounce curve is translated by angular coordinates according to the preset angle, and the hub eccentricity error curve is obtained based on the difference between the translated second bounce curve and the first bounce curve.

[0012] The assembly preload deformation component is determined based on the difference between the first runout curve and the third runout curve, and the brake disc shape error curve is obtained by separating the first runout curve, the wheel hub eccentricity error curve and the assembly preload deformation component.

[0013] The present invention also provides a brake assembly runout detection device, comprising:

[0014] The data acquisition module is used to acquire a first runout curve of the brake assembly under a reference assembly state; after rotating the brake disc relative to the wheel hub by a preset angle, assembling it with the same assembly preload as the reference assembly state, and acquiring a second runout curve of the brake assembly; while maintaining the same relative angular position between the brake disc and the wheel hub as the reference assembly state, changing the assembly preload, and acquiring a third runout curve of the brake assembly; wherein, the first runout curve, the second runout curve, and the third runout curve all characterize the distribution of the positional deviation of the working surface of the brake disc relative to the rotation axis with the rotation angle;

[0015] The hub eccentricity separation module is used to translate the second runout curve by angular coordinates according to the preset angle, and to separate the hub eccentricity error curve based on the difference between the translated second runout curve and the first runout curve.

[0016] The brake disc shape separation module is used to determine the assembly preload deformation component based on the difference between the first runout curve and the third runout curve, and to separate the brake disc shape error curve based on the first runout curve, the hub eccentricity error curve and the assembly preload deformation component.

[0017] The present invention also provides a brake assembly runout detection device, comprising: a memory and at least one processor, wherein the memory stores instructions, and the memory and the at least one processor are interconnected via a circuit; the at least one processor invokes the instructions in the memory to cause the brake assembly runout detection device to perform the steps of the above-described brake assembly runout detection method.

[0018] The present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the steps of the above-described brake assembly runout detection method.

[0019] The technical solution provided in this application focuses on the angular domain runout information of the brake assembly under different controlled assembly states. By constructing multiple runout curves with defined geometric relationships, the various types of errors that were originally superimposed exhibit distinguishable variation patterns in the angular domain. Specifically, the first runout curve obtained in the baseline assembly state fully reflects the overall distribution of the positional deviation of the brake disc's working surface relative to the rotation axis as the angle changes. This distribution simultaneously includes factors such as the shape deviation of the brake disc itself, the eccentricity of the wheel hub relative to the rotation axis, and the elastic deformation caused by assembly preload. Subsequently, while maintaining a consistent assembly preload, the brake disc is rotated relative to the wheel hub by a preset angle and reassembled to obtain the second runout curve. Because the brake disc undergoes a repositioning relative to the wheel hub at a defined angle, the position of the shape deviation of the brake disc's fixed connection in the angular domain is correspondingly translated, while the position of the eccentricity feature of the wheel hub's fixed connection in the angular domain remains unchanged. After the second jump curve is translated by the angular coordinate according to the preset angle, the two curves are aligned under the same angular reference. At this time, the difference between the two curves is no longer dominated by the brake disc shape error, but mainly reflects the systematic angular change caused by the wheel hub eccentricity, so that the wheel hub eccentricity error curve can be separated from the difference.

[0020] Building upon this foundation, the solution further introduces changes in assembly preload as another dimension to differentiate error sources. While maintaining the relative angular position of the brake disc and wheel hub consistent with the baseline assembly state, a third runout curve is obtained by altering the assembly preload force. This ensures that the brake disc shape error and wheel hub eccentricity exhibit consistent behavior in the angular domain, while the elastic deformation caused by assembly preload changes with the preload state. The difference between the first and third runout curves thus centrally reflects the impact of assembly preload changes on the runout distribution, allowing the determination of the assembly preload deformation component. Once both the wheel hub eccentricity error curve and the assembly preload deformation component are obtained, the remaining unexplained portion of the first runout curve under the baseline assembly state corresponds to the shape error distribution of the brake disc itself. Through these steps, the assembly runout, which was originally reflected by a single numerical value, is transformed into multiple curves in the angular domain that can separately characterize different error sources. This clearly presents the influence relationship between brake disc shape error, wheel hub eccentricity error, and assembly preload deformation on runout, thereby achieving effective differentiation and explanation of the causes of brake assembly runout. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of one embodiment of the brake assembly runout detection method in this invention;

[0023] Figure 2 This is a schematic diagram of one embodiment of the brake assembly runout detection device according to the present invention;

[0024] Figure 3 This is a schematic diagram of one embodiment of the brake assembly runout detection device in this invention.

[0025] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] Figure 1The implementation flow of the brake assembly runout detection method provided in this embodiment is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0028] Please see Figure 1 The first runout curve of the brake assembly is obtained under the reference assembly condition;

[0029] Specifically, the above steps refer to the complete recording of the distribution of the positional deviation of the working surface of the brake disc relative to the axis of rotation with the rotation angle, under the condition that the brake disc and the wheel hub are assembled according to the specified assembly preload and their relative positions remain unchanged.

[0030] The baseline assembly state corresponds to the assembly conditions of the brake assembly, which are considered a reference state during normal manufacturing or testing processes. The assembly preload is used to ensure full contact between the brake disc and the hub mating surface, keeping the elastic deformation caused by assembly stable and repeatable. In this state, the brake assembly is continuously rotated around its axis of rotation, and the rotation angle and the positional deviation of the brake disc working surface in a selected detection direction are simultaneously acquired during rotation. The rotation angle, with a fixed angular reference position on the hub as zero, characterizes the angular position of the assembly at each rotation. The positional deviation characterizes the geometric offset of the brake disc working surface relative to the axis of rotation at that angular position. By pairing the acquired rotation angle with the corresponding positional deviation at each moment, a data pair sequence of angular position and runout value is formed, and this data pair sequence covers at least one complete rotation cycle, thus obtaining the first runout curve.

[0031] To ensure that the curve can be directly used for subsequent angular coordinate translation and point-by-point difference calculations, the angular position preferably covers the complete range from 0 degrees to 360 degrees, and the same angular position has a consistent definition in different measurement cycles. When collecting data from multiple rotation cycles, the runout values ​​at the same angular position can be averaged to reduce the influence of random disturbances on the curve shape, making the first runout curve more realistically reflect the comprehensive runout distribution formed by the superposition of brake disc shape error, hub eccentricity, and assembly preload deformation under the reference assembly state. The first runout curve obtained in the above manner completely retains the superposition information of various error sources in the angular domain, and provides a unified, stable, and repeatable data foundation for introducing repositioning and preload change conditions under the same angular reference, and then separating different error sources through difference calculations. In other equivalent embodiments, as long as one-cycle or multi-cycle angular domain runout data with rotation angle as the independent variable and brake disc working surface position deviation as the dependent variable can be obtained under the reference assembly state, and the angular reference consistency is maintained, an equivalent first runout curve can be formed and used for subsequent error separation processing.

[0032] Please continue reading. Figure 1After rotating the brake disc relative to the wheel hub by a preset angle, assemble it with the same assembly preload as the reference assembly state to obtain the second runout curve of the brake assembly.

[0033] It should be noted that the preset angle is the angular repositioning amount of the brake disc relative to the wheel hub between two assembly states, used to make the shape deviation of the brake disc fixed produce a controllable angular misalignment in the rotation angle coordinate; the second runout curve is consistent with the first runout curve in terms of data form, both being angular domain curves that characterize the position deviation of the brake disc working surface relative to the rotation axis as a function of the rotation angle, thereby ensuring that the second runout curve can be translated in the angular coordinate and the difference calculation can be performed with the first runout curve.

[0034] Specifically, after obtaining the first runout curve, the assembly connection between the brake disc and the wheel hub is first disconnected, while keeping the zero reference position of the wheel hub unchanged. Relative position marks are set on the brake disc and the wheel hub to record the relative angle position in the reference assembly state. Then, the brake disc is rotated relative to the center of the wheel hub by a preset angle so that the mounting hole of the brake disc is re-aligned with the corresponding mounting hole of the wheel hub and the assembly is completed. When the assembly is completed, the same assembly preload force as in the reference assembly state is applied to ensure that the contact state of the brake disc and the wheel hub mating surface remains consistent in the two assemblies, thereby avoiding introducing the difference in preload force into the source of the difference between the second runout curve and the first runout curve.

[0035] After assembly, the brake assembly is rotated around the same rotation axis, and the rotation angle and the position deviation of the brake disc working surface are acquired synchronously according to the same detection direction and detection circumferential position as the first runout curve, resulting in a data pair sequence of angle position and corresponding runout value. This data pair sequence covers at least one complete rotation cycle and is sorted by angle position to form the second runout curve. Taking the diagnostic station after assembly turning as an example, after disassembling and assembling the brake disc, it is rotated relative to the wheel hub by a preset angle and tightened according to the assembly preload specified in the process card. Then, one cycle of angle domain position deviation data is collected at the same detection circumferential position as the first runout curve, and the second runout curve can be obtained. Since the brake disc shape deviation is fixed to the brake disc, repositioning will cause the peak and valley positions of the shape deviation in the angle domain to shift as a whole. However, the wheel hub eccentricity is fixed to the wheel hub and the angle reference zero position remains unchanged on the wheel hub side, so that the angle domain features caused by eccentricity remain at the same angle position. Therefore, it provides a distinguishable source of angle information for subsequent alignment of the brake disc shape deviation by angle coordinate translation and highlighting the wheel hub eccentricity error by difference.

[0036] For the setting of the preset angle, the preset angle must meet the assembly hole alignment constraint to ensure assembly. At the same time, the preset angle is not 0 degrees to avoid the two assembly states completely overlapping in the angle domain and thus failing to form a misalignment relationship that can be used for separation. In other equivalent embodiments, the preset angle can be selected as an index angle that matches the distribution of the assembly holes, or the rotation angle of the brake disc relative to the hub can be repeated by setting positioning pins, positioning notches, etc., and the second runout curve can be obtained under the same assembly preload conditions. All of these can obtain the same data structure and angle misalignment relationship as the above embodiments, thereby realizing the input requirements of the second runout curve for the subsequent error separation process.

[0037] In one embodiment of the present invention, the selection of the preset angle includes:

[0038] When the number of mounting holes on the brake disc is even, the preset angle is 180 degrees;

[0039] When the number of mounting holes on the brake disc is odd, the preset angle is an integer multiple of the angle value obtained by dividing 360 degrees by the number of mounting holes, and the preset angle is less than 360 degrees.

[0040] In the above embodiments, the number of mounting holes refers to the number of through holes on the brake disc used to connect with the wheel hub, and the preset angle is the rotation angle of the brake disc relative to the wheel hub during repositioning. Its value must simultaneously satisfy the mounting hole alignment constraint and the non-zero angular misalignment constraint. Specifically, when the number of mounting holes is even, the preset angle is 180 degrees. After rotating the brake disc relative to the wheel hub half a revolution, each mounting hole corresponds to its original hole position, allowing reassembly to be completed without changing the assembly structure. The half-cycle repositioning causes a clear half-cycle misalignment in the angular domain due to the shape deviation of the brake disc's fixed connection, providing a clear reference relationship for subsequent angular coordinate translation and difference separation. For example, after loosening the connection at the assembly inspection station, rotating the brake disc 180 degrees and then assembling it with the same pre-tightening force can achieve this preset angle. It should be noted that this value, through symmetrical repositioning, fixes the phase change and makes it easy to repeat, reducing assembly failures or angular errors caused by mounting hole misalignment.

[0041] When the number of mounting holes is odd, the preset angle is an integer multiple of 360 degrees divided by the number of mounting holes, but less than 360 degrees. This ensures that the rotated mounting holes can be realigned with the corresponding holes on the wheel hub, and avoids identical assembly states due to preset angles of 0 degrees or 360 degrees. Specifically, the number of mounting holes is first determined, then rotation is performed according to the index value, and assembly is carried out after rotation is complete. The preset angle is less than 360 degrees to ensure effective angular misalignment conditions, allowing distinguishable angular displacement of the brake disc's fixed shape deviation within the angular domain. For example, a five-hole brake disc can be preset with 72 degrees or 144 degrees, ensuring that the holes can still be aligned and assembly can be reproduced after rotation. In an equivalent embodiment, the preset angle can also be other integer multiples of the aforementioned angle value, as long as the constraints of mounting hole alignment and the preset angle being less than 360 degrees are met, the same repositioning effect can be obtained and used for subsequent error separation.

[0042] Please continue reading. Figure 1 Under the condition that the relative angular position between the brake disc and the hub is the same as the reference assembly state, the assembly preload is changed to obtain the third runout curve of the brake assembly; wherein, the first runout curve, the second runout curve and the third runout curve all characterize the distribution of the positional deviation of the working surface of the brake disc relative to the axis of rotation with the rotation angle.

[0043] In the above embodiments, keeping the relative angular position of the brake disc and the wheel hub the same as the reference assembly state means that the relative assembly position of the brake disc and the wheel hub at the angular reference zero position does not undergo angular repositioning, ensuring that the phase of the shape deviation of the brake disc fixed connection in the rotational angular coordinate is consistent with the first runout curve, and at the same time ensuring that the phase of the eccentric feature of the wheel hub fixed connection in the rotational angular coordinate is also consistent; the assembly preload is the clamping condition applied by the assembly bolts to the joint interface. Changing the assembly preload is used to make the elastic deformation caused by the assembly preload change with the preload state, thereby introducing an assembly preload difference component that is comparable to the first runout curve into the third runout curve.

[0044] Specifically, during implementation, the angle mark or positioning reference in the reference assembly state is used as a reference. The brake disc and wheel hub are assembled to the same relative angle position as the reference assembly state. At this relative angle position, the original assembly preload is released and a different assembly preload is applied than that in the reference assembly state. The value of the assembly preload must be within the elastic working range of the bolt and the mating surface material to ensure that the fit between the brake disc and the wheel hub can be repeated after changing the assembly preload and that no irreversible deformation occurs. Then, the brake assembly is rotated around the same rotation axis, and the rotation angle and the position deviation of the brake disc working surface are obtained synchronously according to the same detection direction, detection circumferential position and angle reference zero position as the first runout curve. This forms a data pair sequence of angle positions and corresponding runout values ​​covering at least one complete rotation cycle. After sorting by angle position, the third runout curve is obtained. Taking the diagnostic station after assembly turning as an example, after completing the first runout curve, the angle marks of the brake disc and the wheel hub are kept aligned. The assembly preload is adjusted from the target value of the reference assembly state to another target value and then re-tightened. Then, the position deviation data of the angle domain for one cycle is collected at the same detection circumference position to obtain the third runout curve. Since the relative angle position remains unchanged, the brake disc shape deviation and wheel hub eccentricity are shown as repeated distributions at the same angle position in the first and third runout curves. The change of assembly preload will cause the contact pressure distribution and local contact state of the joint interface to change, which in turn will cause the elastic deformation caused by assembly preload to change in the angle domain. Therefore, the difference between the first and third runout curves can reflect the contribution of assembly preload deformation with the change of preload state, providing input for subsequent determination of assembly preload deformation components.

[0045] As an equivalent implementation method, changing the assembly preload can be achieved by uniformly adjusting the tightening level of all assembly bolts, or by tightening them step by step to different target preload levels and obtaining the third runout curves respectively. As long as the relative angle position is consistent with the reference assembly state and the assembly preload changes relative to the reference assembly state, a third runout curve that can be used for difference calculation can be obtained and the same purpose of identifying assembly preload deformation can be achieved.

[0046] Please continue reading. Figure 1 The second bounce curve is translated by angular coordinates according to the preset angle, and the hub eccentricity error curve is obtained based on the difference between the translated second bounce curve and the first bounce curve.

[0047] In one embodiment of the present invention, the step of translating the second jump curve by angular coordinates according to the preset angle includes:

[0048] Establish a data pair sequence for the second bounce curve, wherein each data pair contains an angular position and a corresponding bounce value;

[0049] Subtract the preset angle from each angle position in the data pair sequence. If the result is less than 0 degrees, add 360 degrees. If the result is greater than or equal to 360 degrees, subtract 360 degrees to obtain the translated angle position.

[0050] The translated angular position is recombined with the corresponding jump value to obtain the translated second jump curve.

[0051] The following is a detailed description of the steps involved in the above embodiments:

[0052] It should be noted that the data pair sequence of the second runout curve is used to express the second runout curve in discrete data form and facilitate subsequent angular coordinate translation processing. Each data pair is a binary combination of an angular position and its corresponding runout value. The angular position indicates the rotation angle of the brake assembly within the rotation cycle, and the runout value indicates the positional deviation of the brake disc working surface relative to the rotation axis at that angular position. Specifically, the angular positions and runout values ​​obtained when acquiring the second runout curve are sorted according to the acquisition order or by angular position and then written point-by-point into the data pair sequence. The input to the data pair sequence is the originally acquired angular position and runout value, and the output is a sequence structure containing multiple data pairs. This sequence structure can be stored in the form of a table, array, or key-value mapping, as long as the pairing relationship between each angular position and its corresponding runout value is not disrupted. For example, after completing one cycle of acquisition at the quality diagnostic station, each sampling angle within the range of 0 degrees to 360 degrees and its corresponding runout value are written into the detection record table, forming the data pair sequence of the second runout curve. This process transforms the continuous measurement process into a searchable, point-by-point data set, making it possible to directly reproduce the subsequent consistent translation calculations performed at each angular position.

[0053] Subtracting a preset angle from each angular position in the data pair sequence and performing a 360-degree loop is a discrete implementation of angular coordinate translation. Its purpose is to convert the angular misalignment related to the brake disc's repositioning relative to the wheel hub in the second jump curve into a unified alignment relationship within the coordinate system. Specifically, taking the data pair sequence as input, the preset angle is subtracted from the angular position of each data pair in the sequence; when the result is less than 0 degrees, 360 degrees are added to bring the angular position back to the range of 0 to 360 degrees; when the result is greater than or equal to 360 degrees, 360 degrees are subtracted to bring the angular position back to the range of 0 to 360 degrees. This process is performed on each data pair one by one, and the output is a set of translated angular positions. Taking a five-hole brake disc with a preset angle of 72 degrees as an example, the sampling point with an original angular position of 30 degrees is subtracted by 72 degrees to obtain a negative value, and after looping, it becomes 318 degrees, thus maintaining consistency with the alignment relationship of the same physical position in the angular domain. This process applies the same angular offset to each angular position and wraps around it, ensuring that the translated angular position remains within the single-cycle angular domain, avoiding sorting chaos caused by angular out-of-bounds errors, and enabling subsequent difference calculations to be performed point by point within the same angular domain.

[0054] Recombining the translated angular positions with their corresponding jump values ​​means replacing the original angular positions with the translated angular positions while maintaining a one-to-one correspondence with the jump values, thus obtaining the translated second jump curve. Specifically, using the translated angular position set and the jump values ​​in the original data pair sequence as input, angular position replacement is performed on each data pair to generate new data pairs, forming a new data pair sequence. The output is the translated second jump curve. To facilitate subsequent difference calculations with the first jump curve at the same angular positions, the translated second jump curve can be sorted by angular position from smallest to largest, and duplicate angular positions can be retained according to the acquisition order or merged. For example, after completing the angular loop, sorting all new data pairs by angular position yields a translated sequence within the range of 0 to 360 degrees, which can then be directly aligned with the first jump curve at angular points. The analysis process involves using a preset angle that corresponds to the repositioning amount of the brake disc relative to the wheel hub. Angle position replacement transforms this repositioning from a physical assembly relationship to a data coordinate relationship, allowing the angle distribution of the brake disc's fixed connection to be aligned in the data coordinates. This enables the difference calculation to more accurately reflect the eccentric distribution of the wheel hub's fixed connection. In other equivalent implementations, the recombined, translated second jump curve can be further resampled into an equal-angle interval sequence to adapt to different subsequent alignment strategies, or it can directly enter the point alignment step as an unsorted data pair sequence. Both methods maintain the consistency of the angle coordinate translation results and support the subsequent difference separation process.

[0055] In one embodiment of the present invention, a hub eccentricity error curve is obtained based on the difference between the translated second runout curve and the first runout curve, including:

[0056] Align the angle points of the first jumping curve and the translated second jumping curve. When the angle sampling points of the two curves are not completely consistent, use an interpolation method to generate aligned data points.

[0057] Calculate the point-by-point difference between the two aligned curves at the same angular position to obtain the initial difference curve;

[0058] Perform a Fourier transform on the initial difference curve to extract the first harmonic component with the largest amplitude.

[0059] The first harmonic component is used as the hub eccentricity error curve.

[0060] The following is a detailed description of the steps involved in the above embodiments:

[0061] Specifically, when aligning the first jump curve and the translated second jump curve at their angle points, a target set of angle points is first determined. This target set can be the set of angle sampling points of the first jump curve, the set of angle sampling points of the translated second jump curve, or a set of equally spaced points covered by both curves as a unified angle coordinate. Using the target set of angle points as the output angle position index, a sequence of jump values ​​at each target angle point is generated for each of the two curves. When the angle sampling points of the two curves are not completely consistent, the interpolation method takes adjacent angle sampling points and their jump values ​​as input and outputs the estimated jump value at the target angle point, thus obtaining the aligned first jump curve and the aligned translated second jump curve. The interpolation method can be linear interpolation, which estimates the jump values ​​of adjacent points according to the angular distance ratio, or cubic spline interpolation to obtain a smoother curve shape. In the brake assembly jump detection scenario, linear interpolation can maintain sufficient accuracy and reduce computational load when the angle step size is small. This step eliminates the difference error caused by inconsistent sampling points by using a unified angle index, so that the changes reflected by the subsequent difference are focused on the geometric differences between the two assembly states rather than the sampling point misalignment.

[0062] When calculating the point-by-point difference between the two aligned curves at the same angular position, the first runout curve after alignment and the second runout curve after translation are used as inputs. For each angular position in the target angular point set, the runout values ​​of the two curves are taken and subtracted. The output is an initial difference curve corresponding one-to-one with the target angular point set. The angular position of the initial difference curve is consistent with the input curve, and the runout value is the difference between the two curves at that angular position, thus directly reflecting the remaining difference between the two curves under the same angular reference after translation and alignment. Taking the diagnostic station after assembly turning as an example, if both the first runout curve and the second runout curve after translation are sampled at a step size of 1 degree, the target angular point set is an integer angular point from 0 degrees to 359 degrees, and the point-by-point difference output is 360 difference sampling points. This step compresses the difference between the two assembly states into a single angular domain curve, facilitating the extraction of the eccentric component with clear periodic characteristics from this difference.

[0063] When performing a Fourier transform on the initial difference curve and extracting the first harmonic component with the largest amplitude, the discrete angle sequence of the initial difference curve is used as input, treated as a periodic signal within a complete rotation cycle. A Fourier transform is then performed to obtain the amplitude and phase of each harmonic component. Subsequently, the amplitude and phase corresponding to the first harmonic are selected as the target component, and this target component is reconstructed in the angle domain as a sinusoidal curve that varies with the angle as the output. The reason for choosing the first harmonic component is that wheel hub eccentricity in the angle domain mainly manifests as a systematic offset with a single periodic change, while errors introduced by brake disc shape deviations or assembly contact details are more likely to manifest as higher-order changes or local fluctuations. Retaining the first harmonic component in the initial difference curve can suppress the interference of these higher-order and local components on eccentricity identification, making the output more consistent with the angle domain characteristics of eccentricity. After using this first harmonic component as the wheel hub eccentricity error curve, this curve can be used as the input for subsequently subtracting the wheel hub eccentricity influence from the first jump curve, completing the independent characterization of the wheel hub eccentricity error in the angle domain. As an equivalent implementation method, the Fourier transform can be implemented by the discrete Fourier transform or the fast Fourier transform; the extraction of the first harmonic component can also be obtained by fitting the initial difference curve with a first-order sine function. As long as the output is an angle domain periodic component equivalent to the first harmonic, an equivalent hub eccentricity error curve can be obtained and the same eccentricity separation effect can be achieved.

[0064] Please continue reading. Figure 1 The assembly preload deformation component is determined based on the difference between the first runout curve and the third runout curve, and the brake disc shape error curve is obtained by separating the first runout curve, the hub eccentricity error curve and the assembly preload deformation component.

[0065] In one embodiment of the present invention, determining the assembly preload deformation component based on the difference between the first runout curve and the third runout curve includes:

[0066] Calculate the point-by-point difference between the first runout curve and the third runout curve at the same angular position to obtain the assembly pre-tightening deformation change curve;

[0067] Determine the assembly preload under the reference assembly state and the assembly preload when the third runout curve is obtained, and calculate the change in assembly preload between the two.

[0068] Calculate the characteristic value of the assembly preload deformation change curve, wherein the characteristic value is the root mean square value or peak-to-peak value of the assembly preload deformation change curve;

[0069] Based on the characteristic values ​​of the curves of the change in assembly preload force and the change in assembly preload deformation, the response coefficient between assembly preload deformation and assembly preload force is calculated.

[0070] Based on the response coefficient and the assembly preload under the reference assembly state, the assembly preload deformation component under the reference assembly state is calculated.

[0071] The following is a detailed description of the steps involved in the above embodiments:

[0072] When calculating the point-by-point difference between the first and third runout curves at the same angular position to obtain the assembly preload deformation change curve, the input consists of the first and third runout curves, both expressed as data pairs of angular position and corresponding runout value. If the angular sampling points of the two curves are inconsistent, they are aligned according to a pre-selected set of target angular points, and corresponding runout values ​​are generated at the missing angular positions, ensuring that both curves have runout values ​​output at each target angular point. Subsequently, at each target angular point, the runout value of the third runout curve is subtracted from the runout value of the first runout curve, and the output is the assembly preload deformation change curve corresponding one-to-one with the target angular point set. For example, when 360 sampling points are collected at the same detection circumference position with a 1-degree angular step, the point-by-point difference is directly output as 360 difference points while keeping the angular index unchanged. This processing maps the difference between the two assembly preload conditions into an angular domain curve, facilitating subsequent quantification of its change amplitude using a uniform scale.

[0073] When determining the assembly preload under the baseline assembly condition and the assembly preload when obtaining the third runout curve, and calculating the change in assembly preload, the inputs are the recorded values ​​of the assembly preload under the baseline assembly condition and the recorded values ​​of the assembly preload when obtaining the third runout curve. These recorded values ​​are derived from assembly process documents or assembly process records. The output is the change in assembly preload. In practice, the assembly preload under the baseline assembly condition is taken as the target value of the same set of assembly bolts under specified tightening conditions. The assembly preload when obtaining the third runout curve is taken as the target value after changing the assembly preload. The difference between the two values ​​is used to obtain the change in assembly preload.

[0074] When calculating the characteristic value of the assembly preload deformation change curve, the input is the assembly preload deformation change curve, and the output is a single characteristic value, which is selected as either the root mean square (RMS) value or the peak-to-peak value. In practice, the RMS value is obtained by averaging the squares of all difference points across the entire angle range and then taking the square root, reflecting the overall level of the difference amplitude across the entire angle range. The peak-to-peak value is obtained by taking the difference between the maximum and minimum difference values ​​across the entire angle range, reflecting the maximum range of the difference amplitude. For example, when the assembly preload deformation change curve contains 360 angle points, the RMS value is calculated over the 360 ​​difference points, and the peak-to-peak value is obtained through the global extreme value difference. The difference between the two characteristic value selections is that the RMS value is more sensitive to the global distribution, while the peak-to-peak value is more sensitive to extreme angle points. Therefore, in batch diagnostic scenarios, one of them can be uniformly selected and fixed according to the judgment criteria to avoid incomparable response coefficients caused by mixing criteria between different batches of the same product. In an equivalent implementation, the curve of assembly preload deformation change can be smoothed before calculating the characteristic value to suppress the influence of isolated spikes on the peak-to-peak value. However, the smoothing process needs to fix the parameters in the same decision process to ensure the stability of the response coefficient.

[0075] The response coefficient is calculated based on the characteristic values ​​of the curves showing changes in assembly preload and preload deformation. In practice, the response coefficient is the ratio of the characteristic value to the change in assembly preload, representing the amplitude of the preload deformation change corresponding to a unit change in assembly preload. When the change in assembly preload is positive or negative, the sign of the response coefficient remains consistent with the direction of the difference to ensure a unified calculation method. For example, if the characteristic value is the root mean square (RMS), the response coefficient corresponds to the proportional relationship between the overall amplitude and the change in assembly preload; if the characteristic value is the peak-to-peak value, the response coefficient corresponds to the proportional relationship between the maximum amplitude range and the change in assembly preload. This process establishes a one-to-one quantitative scale between changes in assembly preload deformation and changes in assembly preload, allowing the preload deformation component under the baseline assembly state to be calculated from the baseline assembly preload. In an equivalent implementation, the response coefficient can be calculated by taking the average ratio or the median ratio when the change in assembly preload has multiple levels to reduce the impact of random fluctuations. As long as the definition of the response coefficient maintains the amplitude scale corresponding to a unit change, an equivalent response coefficient can be obtained and used for subsequent calculations.

[0076] Next, the response coefficient is multiplied by the assembly preload under the reference assembly state to obtain the assembly preload deformation amplitude scale under the reference state. This amplitude scale is then used to calibrate the angular distribution of the assembly preload deformation change curve, so that the output assembly preload deformation component includes both the angular distribution shape and the amplitude level corresponding to the reference assembly preload force. In the production line diagnostic station, the assembly preload deformation component can be used as input to deduct the influence of assembly preload when subsequently separating the brake disc shape error curve. This processing transforms the deformation caused by assembly preload from a differential change into a component representation that can be directly used under the reference assembly state, thus participating in the decomposition of the first runout curve together with the wheel hub eccentricity error curve. In an equivalent implementation, multiple third runout curves can be obtained while maintaining the same relative angular position as the reference assembly state, and multiple sets of response coefficients can be calculated for each. Then, a representative value with a consistent caliber can be used to calculate the assembly preload deformation component to enhance the stability of the calculation results under different tightening levels, without changing the way the assembly preload deformation component is used in the subsequent error separation process.

[0077] In one embodiment of the present invention, after calculating the response coefficient, the method further includes:

[0078] Based on the assembly preload in the baseline assembly state, select an assembly preload different from the one used to obtain the third runout curve, and obtain at least one verification runout curve.

[0079] Calculate the difference between the at least one verified runout curve and the first runout curve to obtain the verified assembly preload deformation change amount;

[0080] Based on the response coefficient and the corresponding change in assembly preload, the expected change in assembly preload deformation is calculated and compared with the verified change in assembly preload deformation to verify the accuracy of the response coefficient.

[0081] The following is a detailed description of the steps involved in the above embodiments:

[0082] It should be noted that the verification runout curve refers to the runout curve obtained after selecting another assembly preload force based on the assembly preload force of the reference assembly state and completing the assembly. This curve is used to verify the applicability of the aforementioned response coefficient under different assembly preload force variations. Specifically, while maintaining the relative angular position of the brake disc and wheel hub consistent with the reference assembly state and the detection direction consistent with the detection circumference, the assembly preload force of the reference assembly state is used as a reference. A different assembly preload force than that used to obtain the third runout curve is selected as the verification assembly preload force, and the assembly is completed. Subsequently, at least one verification runout curve is obtained using the same angular sampling caliber as the first runout curve. For example, if the assembly preload force corresponding to the third runout curve is at a lower tightening level, the verification assembly preload force can be at a higher tightening level, so that the change in verification assembly preload force is opposite in direction to the change in the aforementioned assembly preload force, thereby covering a wider range of assembly preload force variations. This step, by introducing an independent assembly preload force level, ensures that subsequent comparisons do not rely on the same set of measurement data, thus more directly reflecting the reproducibility of the response coefficient. In an equivalent implementation, the verification assembly preload can be set to multiple different levels and multiple verification runout curves can be obtained respectively. As long as the assembly preload corresponding to each verification runout curve is different from the assembly preload when the third runout curve is obtained, a sample set that can be used for verification can be formed.

[0083] When calculating the difference between at least one verification runout curve and the first runout curve to obtain the verified change in assembly preload deformation, the first runout curve and the verification runout curve are used as inputs. First, the two curves are aligned according to a pre-selected set of angle points, ensuring that both curves have runout values ​​at the same angular positions. Then, at each same angular position, the runout value of the verification runout curve is subtracted from the runout value of the first runout curve, and the output is the verified change in assembly preload deformation. Since the verification runout curve and the first runout curve maintain the same relative angular position between the brake disc and the hub, the angular distribution of the brake disc shape error and the hub eccentricity error in the two curves is the same. The difference in the angular domain mainly reflects the change in assembly preload deformation caused by the verification assembly preload force relative to the reference assembly state, thus obtaining a verification quantity that can be directly compared with the expected value.

[0084] When calculating and comparing the expected change in assembly preload deformation based on the response coefficient and the corresponding change in assembly preload force, the change in assembly preload force corresponding to the verification runout curve is first determined. This change in assembly preload force is the difference between the verified assembly preload force and the assembly preload force under the baseline assembly state. Then, using this change in assembly preload force and the response coefficient as input, the amplitude scale of the expected change in assembly preload deformation is calculated. This amplitude scale is then compared with the verified change in assembly preload deformation under the same statistical caliber. The statistical caliber can be either root mean square (RMS) or peak-to-peak value, and should be consistent with the calculation of the response coefficient. For example, when the response coefficient is calculated based on the RMS value, the RMS value is also calculated for the verified change in assembly preload deformation and compared with the expected amplitude. When the difference between the two is within a preset tolerance range, it is confirmed that the response coefficient can stably characterize the response relationship of assembly preload deformation under this change in assembly preload force. It can be understood that verifying the transferability of the response coefficient through independent assembly preload force levels avoids the response coefficient being effective only for a single change in assembly preload force, thus affecting the reliability of subsequent calculations of assembly preload deformation components.

[0085] In the above embodiment, in the step of "separating the brake disc shape error curve based on the first runout curve, the hub eccentricity error curve, and the assembly preload deformation component," when separating the brake disc shape error curve, the first runout curve, the hub eccentricity error curve, and the assembly preload deformation component are used as inputs. First, it is ensured that the three are expressed using a consistent set of angle points. When the angle sampling points of the hub eccentricity error curve or the assembly preload deformation component are inconsistent with the first runout curve, an interpolation method is used to generate corresponding runout values ​​on the angle point set of the first runout curve, ensuring that the three curves have a unique corresponding value at each angle position. Subsequently, at each identical angle position, the runout value of the first runout curve is calculated by subtracting the corresponding value of the hub eccentricity error curve, and then subtracting the corresponding value of the assembly preload deformation component, outputting the brake disc shape error curve. This output still maintains the same angle position as the first runout curve, and its runout value only includes the distribution of the brake disc body fixing error in the angle domain, thus enabling direct identification of the high and low points of the brake disc working surface at different angle positions. Taking the quality diagnosis station after assembly turning as an example, the first runout curve is sampled at 1 degree angle step to form 360 angle points. The hub eccentricity error curve is reconstructed from the aforementioned first harmonic component and mapped to the same angle point. The assembly preload deformation component is also given at the same angle point. The brake disc shape error curve can be obtained by subtracting the three points one by one. This curve can be used as a direct representation of the brake disc machining quality and turning finish, and is used to determine whether the brake disc shape deviation shows multi-peak characteristics or whether there are local anomalies.

[0086] It is understood that the hub eccentricity error curve and the assembly preload deformation component correspond to two superimposed components in the first runout curve in the angular domain, and they can correspond point by point under the same angular coordinates as the first runout curve. Therefore, the remaining term after point-by-point subtraction only retains the shape error information of the brake disc fixing in the angular domain, so that the error sources originally mixed in the total runout are separated into interpretable independent components. In an equivalent implementation, point-by-point subtraction can be carried out by first adding the hub eccentricity error curve and the assembly preload deformation component point by point to form a comprehensive compensation curve, and then subtracting the comprehensive compensation curve point by point from the first runout curve to obtain the brake disc shape error curve; or the hub eccentricity error curve and the assembly preload deformation component can be smoothed before point-by-point subtraction to suppress the amplification effect of discrete noise on the subtraction result. As long as the angular points are kept consistent and the same difference caliber is used, an equivalent brake disc shape error curve can be obtained and meet the needs of subsequent diagnostic use.

[0087] In one embodiment of the present invention, after obtaining the brake disc shape error curve, the method further includes:

[0088] The brake disc shape error curve, the wheel hub eccentricity error curve, and the assembly preload deformation component are superimposed point by point at the same angular position to obtain the reconstructed runout curve.

[0089] Calculate the point-by-point difference between the reconstructed jump curve and the first jump curve to obtain the residual curve, and calculate the root mean square value of the residual curve;

[0090] When the root mean square value of the residual curve is less than a preset threshold, the separation result is confirmed to be valid; when the root mean square value of the residual curve is greater than or equal to the preset threshold, the number of measurements is increased or the preset angle is adjusted to optimize the separation result.

[0091] The following is a detailed description of the steps involved in the above embodiments:

[0092] When reconstructing the runout curve by superimposing the brake disc shape error curve, wheel hub eccentricity error curve, and assembly preload deformation component at the same angular position, three angular domain curves are used as input. First, it is ensured that all three are expressed using a consistent set of angular points. When the angular sampling point of one curve is inconsistent with other curves, an interpolation method is used to generate a corresponding value on the target angular point set, ensuring that each of the three curves has a unique corresponding value at each angular position. Then, the corresponding values ​​of the three curves are added point-by-point at each same angular position to output the reconstructed runout curve. Taking the quality diagnosis station after assembly turning as an example, if the first runout curve forms 360 angular points with a 1-degree angular step, then mapping the brake disc shape error curve, wheel hub eccentricity error curve, and assembly preload deformation component to these 360 ​​angular points and adding them point-by-point yields the reconstructed runout curve. It is understandable that if the three types of components obtained by separation do indeed constitute the main source of the first jump curve, then their superposition at the same angular position should be able to reproduce the overall shape and amplitude distribution of the first jump curve, thus providing a direct comparison for subsequent residual analysis.

[0093] When calculating the point-by-point difference between the reconstructed runout curve and the first runout curve to obtain the residual curve and calculating the root mean square (RMS) value of the residual curve, the reconstructed runout curve and the first runout curve are used as inputs. The residual curve is obtained by subtracting each point from the consistent set of angle points. The value of the residual curve at each angle position reflects the unexplained error at that angle position. Subsequently, the RMS value of the residual curve is calculated to reflect the overall amplitude level of the residual over the entire cycle, thus avoiding the dominance of random spikes at a single angle point in the judgment. It can be understood that if there is a deviation in the extraction of the hub eccentricity error curve and the assembly preload deformation component during the separation process, or if there is a systematic error in angle alignment, the reconstructed runout curve will continuously deviate from the first runout curve over the entire cycle, and the RMS value of the residual curve will increase accordingly. Conversely, if the separation result is consistent with the first runout curve, the residual mainly consists of measurement noise and discrete interpolation error, and its RMS value will remain at a low level.

[0094] When the root mean square (RMS) value of the residual curve is less than a preset threshold, the separation result is considered valid. When the RMS value of the residual curve is greater than or equal to the preset threshold, the number of measurements can be increased or the preset angle adjusted to optimize the separation result. The preset threshold can be determined in conjunction with the repeatability of the station measurement. For example, in the baseline assembly state, the first runout curve can be repeatedly acquired multiple times for the same brake assembly, and the RMS value of their mutual differences can be calculated. This repeatability index can be multiplied by a safety factor to obtain the preset threshold, so that the threshold matches the actual noise level and avoids misjudging normal noise as separation failure. When the RMS value does not meet the threshold, the number of measurements can be increased by increasing the number of rotation cycles for the first, second, or third runout curves and averaging the same angular positions to reduce the amplification of random noise in separation and reconstruction. The preset angle can be adjusted by selecting another preset angle that is compatible with the alignment constraint of the assembly hole, so that the angular misalignment relationship caused by the repositioning of the brake disc relative to the wheel hub is more conducive to the stable execution of subsequent difference and harmonic extraction.

[0095] The brake assembly runout detection method in the embodiments of the present invention has been described above. The brake assembly runout detection device in the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 2 One embodiment of the brake assembly runout detection device of the present invention includes:

[0096] The data acquisition module 101 is used to acquire a first runout curve of the brake assembly under a reference assembly state; after rotating the brake disc relative to the wheel hub by a preset angle, assembling it with the same assembly preload as the reference assembly state, and acquiring a second runout curve of the brake assembly; while maintaining the same relative angular position between the brake disc and the wheel hub as the reference assembly state, changing the assembly preload, and acquiring a third runout curve of the brake assembly; wherein, the first runout curve, the second runout curve, and the third runout curve all characterize the distribution of the positional deviation of the working surface of the brake disc relative to the rotation axis with the rotation angle;

[0097] The hub eccentricity separation module 102 is used to translate the second jump curve by angular coordinates according to the preset angle, and to separate the hub eccentricity error curve based on the difference between the translated second jump curve and the first jump curve.

[0098] The brake disc shape separation module 103 is used to determine the assembly preload deformation component based on the difference between the first runout curve and the third runout curve, and to separate the brake disc shape error curve based on the first runout curve, the wheel hub eccentricity error curve and the assembly preload deformation component.

[0099] above Figure 2The brake assembly runout detection device in this embodiment of the invention will be described in detail from the perspective of modular functional entities. The brake assembly runout detection device in this embodiment of the invention will be described in detail from the perspective of hardware processing.

[0100] Figure 3 This is a schematic diagram of a brake assembly runout detection device 200 provided in an embodiment of the present invention. The brake assembly runout detection device 200 can vary significantly due to different configurations or performance characteristics. It may include one or more processors 210 (e.g., one or more processors) and a memory 220, and one or more storage media 230 (e.g., one or more mass storage devices) storing application programs 233 or data 232. The memory 220 and storage media 230 can be temporary or persistent storage. The program stored in the storage media 230 may include one or more modules (not shown in the diagram), each module including a series of instruction operations on the brake assembly runout detection device 200. Furthermore, the processor 210 may be configured to communicate with the storage media 230 and execute the series of instruction operations in the storage media 230 on the brake assembly runout detection device 200 to implement the steps of the aforementioned brake assembly runout detection method.

[0101] The brake assembly runout detection device 200 may also include one or more power supplies 240, one or more wired or wireless network interfaces 250, one or more input / output interfaces 260, and / or one or more operating systems 231, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. Those skilled in the art will understand that... Figure 3 The illustrated brake assembly runout detection device structure does not constitute a limitation on the brake assembly runout detection device provided by the present invention. It may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0102] The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the brake assembly runout detection method.

[0103] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system, device, or unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0104] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0105] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A brake assembly rattle detection method, characterized by, The method comprises: acquiring a first runout curve of the brake assembly in a reference assembly state; after rotating the brake disc relative to the hub by a preset angle, assembling the brake assembly under the same assembly pretightening force as in the reference assembly state to acquire a second runout curve of the brake assembly; changing the assembly pretightening force while keeping the relative angular position of the brake disc and the hub the same as in the reference assembly state to acquire a third runout curve of the brake assembly; wherein the first runout curve, the second runout curve and the third runout curve all represent the distribution of the positional deviation of the working surface of the brake disc relative to the rotation axis with the rotation angle; performing angular coordinate translation on the second runout curve according to the preset angle, and separating a hub eccentric error curve based on the difference between the translated second runout curve and the first runout curve; determining an assembly pretightening deformation component based on the difference between the first runout curve and the third runout curve, and separating a brake disc shape error curve based on the first runout curve, the hub eccentric error curve and the assembly pretightening deformation component.

2. The brake assembly rattle detection method of claim 1, wherein, The angular coordinate translation on the second runout curve according to the preset angle comprises: establishing a data pair sequence of the second runout curve, wherein each data pair contains an angular position and a corresponding runout value; subtracting the preset angle from each angular position in the data pair sequence, and adding 360 degrees when the result is less than 0 degrees, or subtracting 360 degrees when the result is greater than or equal to 360 degrees to obtain a translated angular position; recombining the translated angular position and the corresponding runout value to obtain a translated second runout curve.

3. The brake assembly rattle detection method of claim 2, wherein, The separation of the hub eccentric error curve based on the difference between the translated second runout curve and the first runout curve comprises: aligning the angular point positions of the first runout curve and the translated second runout curve, and generating aligned data points by using an interpolation method when the angular sampling points of the two curves are not completely consistent; calculating the point-by-point difference between the two aligned curves at the same angular positions to obtain an initial difference curve; performing Fourier transform on the initial difference curve to extract a first-order harmonic component with the largest amplitude; taking the first-order harmonic component as the hub eccentric error curve.

4. The brake assembly rattle detection method of claim 1, wherein, The determination of the assembly pretightening deformation component based on the difference between the first runout curve and the third runout curve comprises: calculating the point-by-point difference between the first runout curve and the third runout curve at the same angular positions to obtain an assembly pretightening deformation change curve; determining the assembly pretightening force in the reference assembly state and the assembly pretightening force when the third runout curve is acquired, and calculating the assembly pretightening force change therebetween; calculating the characteristic value of the assembly pretightening deformation change curve, wherein the characteristic value is the root mean square value or the peak-to-peak value of the assembly pretightening deformation change curve; calculating the response coefficient between the assembly pretightening deformation and the assembly pretightening force based on the assembly pretightening force change and the characteristic value of the assembly pretightening deformation change curve; calculating the assembly pretightening deformation component in the reference assembly state based on the response coefficient and the assembly pretightening force in the reference assembly state.

5. The brake assembly rattle detection method of claim 4, wherein, After the response coefficient is calculated, further comprising: On the basis of the assembly preload in the reference assembly state, a different assembly preload than that when the third run-out curve is obtained is selected to obtain at least one verification run-out curve; A difference between the at least one verification run-out curve and the first run-out curve is calculated to obtain a verified assembly preload deformation change amount; Based on the response coefficient and the corresponding assembly preload deformation change amount, an expected assembly preload deformation change amount is calculated and compared with the verified assembly preload deformation change amount to verify the accuracy of the response coefficient.

6. The brake assembly rattle detection method of claim 1, wherein, After the brake disc shape error curve is separated, further comprising: The brake disc shape error curve, the hub eccentric error curve and the assembly preload deformation component are point-by-point superimposed at the same angular position to obtain a reconstructed run-out curve; A point-by-point difference between the reconstructed run-out curve and the first run-out curve is calculated to obtain a residual error curve, and a root mean square value of the residual error curve is calculated; When the root mean square value of the residual error curve is less than a preset threshold value, it is confirmed that the separation result is valid; when the root mean square value of the residual error curve is greater than or equal to the preset threshold value, the number of measurements is increased or the preset angle is adjusted to optimize the separation result.

7. The brake assembly rattle detection method of any one of claims 1-6, wherein, The selection of the preset angle comprises: When the number of assembly holes of the brake disc is even, the preset angle is 180 degrees; When the number of assembly holes of the brake disc is odd, the preset angle is an integer multiple of an angle value obtained by dividing 360 degrees by the number of assembly holes, and the preset angle is less than 360 degrees.

8. A brake assembly rattle detection apparatus, characterized by, Comprise: A data acquisition module is configured to acquire a first run-out curve of a brake assembly in a reference assembly state; After rotating the brake disc relative to the hub by a preset angle, the brake disc is assembled under the same assembly preload as in the reference assembly state to obtain a second run-out curve of the brake assembly; the assembly preload is changed while keeping the relative angular position of the brake disc and the hub the same as in the reference assembly state to obtain a third run-out curve of the brake assembly; wherein the first run-out curve, the second run-out curve and the third run-out curve all represent the distribution of the positional deviation of the working surface of the brake disc relative to the rotation axis with the rotation angle; A hub eccentric separation module is configured to perform angular coordinate translation on the second run-out curve according to the preset angle, and separate a hub eccentric error curve based on the difference between the translated second run-out curve and the first run-out curve; A brake disc shape separation module is configured to determine an assembly preload deformation component based on the difference between the first run-out curve and the third run-out curve, and separate a brake disc shape error curve based on the first run-out curve, the hub eccentric error curve and the assembly preload deformation component.

9. A brake assembly rattle detection apparatus, characterized by, The brake assembly run-out detection device comprises a memory and at least one processor, and the memory stores instructions; The at least one processor invokes the instructions in the memory to enable the brake assembly run-out detection device to perform the steps of the brake assembly run-out detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon instructions, the instructions comprising, The instructions, when executed by the processor, implement the steps of the brake assembly run-out detection method of any one of claims 1 to 7.

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