A motorcycle rearview mirror anti-shake design method

Abstract

The present application relates to the technical field of motorcycle vibration control, and specifically discloses a kind of motorcycle rearview mirror anti-shaking design method, the method comprises: obtaining multiple historical frame vibration amplitudes of motorcycle, and multiple historical mirror surface shaking amplitudes;According to the multiple historical frame vibration amplitudes, establish frame vibration distribution matrix, and according to the multiple historical mirror surface shaking amplitudes, establish mirror surface shaking distribution matrix;The coupling transfer coefficient of the frame vibration distribution matrix and the mirror surface shaking distribution matrix is calculated, and the vibration transmission coupling matrix is obtained;The original connection stiffness parameter of rearview mirror is iteratively corrected using the vibration transmission coupling matrix, and the target connection stiffness parameter is obtained.The method can effectively reduce the shaking amplitude of rearview mirror under multiple working conditions by quantifying the coupling transmission relationship between frame vibration and mirror surface shaking and iteratively optimizing the connection stiffness based on the relationship.

Description

Technical Field

[0001] This invention relates to the field of motorcycle vibration control technology, specifically to a method for designing anti-shake features for motorcycle rearview mirrors. Background Technology

[0002] During motorcycle operation, vibrations generated by the engine and road surface are transmitted through the frame to the rearview mirrors, causing the mirrors to vibrate and affecting the rider's clear view of traffic conditions behind. To alleviate this problem, existing technologies typically employ passive vibration isolation measures such as increasing the stiffness of the mirror connection structure and adding rubber damping pads or elastic bushings. However, these conventional design methods treat frame vibration as a single input source, neglecting the differences in vibration amplitude distribution at different speeds and frequencies, and also failing to consider the impact of varying degrees of looseness in the mirror connection structure on vibration transmission characteristics.

[0003] In practical use, the stiffness of the rearview mirror connection point degrades nonlinearly due to long-term vibration, resulting in a complex dynamic coupling relationship between the mirror surface vibration amplitude and the vehicle frame vibration amplitude. Existing methods cannot quantify the variation of this coupling relationship across different frequency ranges, nor can they determine an ideal connection stiffness value that can adapt to multiple operating conditions. This leads to significant resonance or amplified vibration in the rearview mirror even at high speeds or within specific speed ranges. The problem to be solved is how to establish a coupling transmission model between the vehicle frame vibration distribution and the mirror surface vibration distribution, and how to use this model to specifically adjust the connection stiffness parameters to obtain the optimal stiffness value. Summary of the Invention

[0004] This invention aims to provide a method for anti-vibration design of motorcycle rearview mirrors. By establishing a frame vibration distribution matrix and a mirror vibration distribution matrix and calculating the vibration transmission coupling matrix between the two, the original connection stiffness parameters of the rearview mirror are iteratively corrected using this coupling matrix to obtain the optimal target connection stiffness parameters that can adapt to different driving speed ranges and vibration frequencies.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for stabilizing motorcycle rearview mirrors includes: The system acquires multiple historical frame vibration amplitudes of the motorcycle at multiple preset vibration frequencies within multiple preset driving speed ranges, and acquires multiple historical mirror vibration amplitudes of the rearview mirror at multiple preset vibration frequencies under multiple preset looseness levels. Specifically, a first set of acceleration sensing devices (preferably triaxial MEMS accelerometers) is installed at key nodes of the motorcycle frame. When the motorcycle is traveling at a first preset speed range, the peak vibration displacement of the motorcycle frame at multiple preset vibration frequencies is collected. The peak vibration displacement values ​​are archived according to the preset speed range and preset vibration frequency to obtain multiple historical frame vibration amplitudes. Simultaneously, a second set of acceleration sensing devices (also preferably triaxial MEMS accelerometers) is installed on the edge of the rearview mirror. When the rearview mirror is at a first preset looseness, the multiple preset vibration frequencies are applied to the rearview mirror to excite vibration. The peak shaking displacement of the rearview mirror surface at the multiple preset vibration frequencies is collected. The peak shaking displacement values ​​are archived according to the preset looseness and preset vibration frequency to obtain multiple historical mirror shaking amplitudes. Then, the above collection steps are repeated for each preset speed range and multiple preset looseness until all preset speed ranges and all preset looseness corresponding to the frame vibration amplitude and mirror shaking amplitude are filled. By collecting comprehensive data across multiple speed ranges and degrees of looseness, the response characteristics of frame vibration and mirror vibration under different working conditions and assembly states can be accurately characterized, laying a reliable data foundation for subsequent coupled analysis.

[0006] A frame vibration distribution matrix is ​​established based on the multiple historical frame vibration amplitudes, and a mirror vibration distribution matrix is ​​established based on the multiple historical mirror vibration amplitudes. Specifically, the multiple preset driving speed ranges are arranged in ascending order of speed value as the first matrix row index, and the multiple preset vibration frequencies are arranged in ascending order of frequency value as the first matrix column index. The historical frame vibration amplitude corresponding to the intersection of each first matrix row index and each first matrix column index is filled into the matrix element to obtain the frame vibration distribution matrix. The multiple preset looseness degrees are arranged in ascending order of looseness value as the second matrix row index, and the multiple preset vibration frequencies are arranged in ascending order of frequency value as the second matrix column index. The historical mirror vibration amplitude corresponding to the intersection of each second matrix row index and each second matrix column index is filled into the matrix element to obtain the mirror vibration distribution matrix. Then, the frame vibration distribution matrix is ​​normalized to obtain a normalized frame vibration distribution matrix, and the mirror vibration distribution matrix is ​​normalized to obtain a normalized mirror vibration distribution matrix. Matrix representation and normalization can eliminate differences in dimensions and amplitude scales, making vibration data under different working conditions and different degrees of loosening comparable, thereby improving the accuracy and robustness of subsequent coupling coefficient calculation.

[0007] The coupling transfer coefficients between the frame vibration distribution matrix and the mirror vibration distribution matrix are calculated to obtain the vibration transfer coupling matrix. Specifically, the transpose of the normalized frame vibration distribution matrix is ​​multiplied by the normalized frame vibration distribution matrix to obtain the frame autocorrelation matrix; the normalized mirror vibration distribution matrix is ​​multiplied by the transpose of the normalized frame vibration distribution matrix to obtain the cross-correlation matrix between the frame and the mirror; each element in the cross-correlation matrix is ​​divided by the element at the corresponding diagonal position in the frame autocorrelation matrix to obtain the initial coupling transfer coefficient matrix. This process can be formally expressed as follows: The normalized frame vibration distribution matrix is ​​defined as follows: Its dimensions are ,in The number of preset driving speed ranges, The number of preset vibration frequencies; the normalized mirror vibration distribution matrix is ​​defined as follows: Its dimensions are ,in The preset number of looseness levels is used. The autocorrelation matrix of the frame is calculated. Its dimensions are , For matrix Transpose of the matrix; calculate the cross-correlation matrix between the vehicle frame and the mirror. Its dimensions are ; Calculate the initial coupling transfer coefficient matrix Its elements Obtained from the following formula: ; in, It is a matrix The Middle line, number Column elements, It is a matrix The Middle line, number Column elements, It is a matrix The first diagonal of the middle main One element, A very small positive number pre-defined to prevent division by zero errors. The maximum value function is then used. All coefficients in the initial coupling transfer coefficient matrix that are less than a preset transfer threshold are set to zero, while all coefficients greater than or equal to the preset transfer threshold remain unchanged, thus obtaining the vibration transfer coupling matrix. The preset transfer threshold is determined by the median of the statistical distribution of the vibration transfer coefficients. The coupling transfer coefficients obtained through autocorrelation and cross-correlation operations can quantitatively reveal the path strength of the vehicle frame vibration energy transferred to the rearview mirror surface. Threshold truncation filters out weak coupling noise, allowing subsequent stiffness correction to focus on the main transmission modes that dominate the vibration, thus improving iteration efficiency.

[0008] The original connection stiffness parameters of the rearview mirror are iteratively corrected using the vibration transmission coupling matrix to obtain the target connection stiffness parameters. Specifically, firstly, the elastic modulus of the bolt material, the effective bearing cross-sectional area of ​​the bolt, and the initial preload elongation of the bolt are obtained; the elastic modulus of the bolt material is multiplied by the effective bearing cross-sectional area of ​​the bolt to obtain an intermediate product result, and then the intermediate product result is divided by the initial preload elongation of the bolt to obtain the original connection stiffness parameters; the original connection stiffness parameters are assigned to the current iteration variable to obtain the current iteration stiffness parameters. Then, the current iteration stiffness parameters are multiplied by the maximum transmission coefficient in the vibration transmission coupling matrix to obtain the stiffness correction step size. Specifically, from the vibration transmission coupling matrix... Extract all non-zero elements to form a set of non-zero transit coefficients. From the set of non-zero transfer coefficients Find the maximum value in the range and use it as the maximum transmission coefficient. The current iteration stiffness parameter is denoted as... The stiffness correction step size is calculated using the following formula. : ; in, The preset damping factor has a value range of (0,1). Next, the current iterative stiffness parameter is subtracted from the stiffness correction step size to obtain the updated iterative stiffness parameter: the current iterative stiffness parameter is defined as... superscript Indicates the first The next iteration; the stiffness correction step size is defined as... The updated iterative stiffness parameters are calculated using the following formula. : ; Calculation results The updated iterative stiffness parameter is used as the current iterative stiffness parameter for the next iteration. Then, it is determined whether the updated iterative stiffness parameter is less than a preset minimum stiffness threshold. If the updated iterative stiffness parameter is less than the preset minimum stiffness threshold, the current iterative stiffness parameter is used as the target connection stiffness parameter. If the updated iterative stiffness parameter is greater than or equal to the preset minimum stiffness threshold, the updated iterative stiffness parameter is used as the new current iterative stiffness parameter, and the stiffness correction step size is recalculated. Iterative correction continues until the number of iterations reaches a preset maximum number of iterations. The iterative stiffness parameter obtained in the last iteration is used as the target connection stiffness parameter. This iterative correction process uses the maximum transmission coefficient in the vibration transmission coupling matrix as an indicator of the dominant coupling strength. By successively reducing the connection stiffness, the vibration transmission path from the frame to the mirror surface is cut off or weakened. Simultaneously, a damping factor is introduced to control the convergence speed and stability, ultimately obtaining a target stiffness value that ensures connection reliability while effectively suppressing vibration.

[0009] As a preferred embodiment, before iteratively correcting using the vibration transmission coupling matrix, a natural frequency avoidance judgment can be performed. Specifically, the mirror mass parameter and mirror moment of inertia parameter of the rearview mirror surface are obtained, as are the equivalent length parameter and cross-sectional modulus parameter of the rearview mirror bracket; the natural frequency estimate of the rearview mirror system is obtained by multiplying the mirror mass parameter and the mirror moment of inertia parameter by the product of the equivalent length parameter and the cross-sectional modulus parameter of the bracket. This estimation process can be expressed as: defining the mass of the rearview mirror surface as... The moment of inertia of the mirror on its centroidal axis is The equivalent length of the rearview mirror bracket is defined as follows: The section modulus of the support is The estimated natural frequency of the rearview mirror system can be calculated using the following formula. : ; in, The structural coefficients related to the rearview mirror mounting method were obtained by fitting pre-calibrated experimental data. Pi This represents the square root operation. Then, it is determined whether the difference between the estimated natural frequency and the dominant vibration frequency of the motorcycle engine is less than a preset frequency avoidance threshold. If the difference is less than the preset frequency avoidance threshold, it indicates a resonance risk, and the above iterative correction steps are executed. If the difference is greater than or equal to the preset frequency avoidance threshold, it indicates that the system naturally avoids the resonance zone, and the original connection stiffness parameter is directly output as the target connection stiffness parameter, thereby avoiding unnecessary stiffness adjustments and saving design costs.

[0010] After obtaining the target connection stiffness parameters, the method further includes verification and feedback optimization steps. The target preload torque of the connecting bolts is calculated backwards based on the target connection stiffness parameters, and the connecting bolts of the rearview mirror are tightened according to the target preload torque. Specifically: Obtaining the target connection stiffness parameters... The thread pitch diameter of the rearview mirror connecting bolt The coefficient of friction between the bolt and the connecting base and the elastic modulus of the bolt material ; Calculate the target preload of the connecting bolts ,in The initial deformation design value for the connection system; based on the target preload. Calculate the target preload torque : ; in, For thread helix angle, The value is the tangent of the thread helix angle; use a torque wrench to apply the calculated target preload torque. Tighten the connecting bolts of the rearview mirror. Then, affix reflective markers to the mirror surface after tightening, and continuously capture multiple actual vibration trajectory images of the reflective markers using a high-speed camera while the motorcycle is in motion. Extract the actual maximum vibration amplitude of the mirror surface from these multiple vibration trajectory images, and determine whether the actual maximum vibration amplitude is less than a preset anti-vibration qualification threshold. If the actual maximum vibration amplitude is greater than or equal to the preset anti-vibration qualification threshold, reacquire multiple historical frame vibration amplitudes and multiple historical mirror vibration amplitudes, recalculate the vibration transmission coupling matrix, and perform a secondary correction on the target connection stiffness parameters. This closed-loop verification mechanism can effectively evaluate the actual anti-vibration effect and automatically trigger a new round of optimization when it fails to meet the standard, ensuring that the final design meets the usage requirements.

[0011] Furthermore, this method can be extended to adapt to multiple motorcycle models. After obtaining the target connection stiffness parameters, these parameters are substituted into the frame vibration distribution matrices corresponding to multiple different motorcycle models to calculate the predicted vibration amplitude of the rearview mirror for each model. The predicted vibration amplitude of the rearview mirror for each motorcycle model is compared with the preset vibration tolerance threshold for the corresponding model, and a set of risky models whose predicted vibration amplitude exceeds the preset vibration tolerance threshold is selected. For each risky model in the set, its unique frame structure features are extracted, and the target connection stiffness parameters are individually fine-tuned based on these unique frame structure features to obtain personalized connection stiffness parameters for that risky model. This extended scheme enables general design parameters to be quickly adapted to different models, reduces repetitive calibration work, and improves the universality of the design method.

[0012] As another preferred solution, after obtaining the vibration transmission coupling matrix, an additional damping treatment scheme can be generated. Specifically, each transmission coefficient in the vibration transmission coupling matrix is ​​divided into high transmission, medium transmission, and low transmission segments according to its numerical value; the preset vibration frequencies corresponding to the transmission coefficients in the high transmission segments are statistically analyzed to form a high-risk frequency set, and the preset vibration frequencies corresponding to the transmission coefficients in the medium transmission segments are statistically analyzed to form a medium-risk frequency set; a first set of damping material attachment position indicators is generated based on the high-risk frequency set, and a second set of damping material attachment thickness indicators is generated based on the medium-risk frequency set; the first set of damping material attachment position indicators and the second set of damping material attachment thickness indicators are combined and output as the additional damping treatment scheme for the rearview mirror. This scheme can differentiate the placement position and thickness of the damping material according to the vibration coupling intensity of different frequency bands, further absorbing residual vibration energy on the basis of optimized connection stiffness, and realizing multi-level anti-vibration design.

[0013] The beneficial effects of this invention are: By acquiring historical frame vibration amplitudes of motorcycles at multiple preset speed ranges corresponding to multiple preset vibration frequencies, and historical mirror vibration amplitudes of rearview mirrors at multiple preset looseness levels corresponding to multiple preset vibration frequencies, frame vibration distribution matrices and mirror vibration distribution matrices are established respectively. The coupling transmission coefficients of the two matrices are then calculated to obtain a vibration transmission coupling matrix. This quantifies the dynamic transmission relationship between frame vibration amplitudes and rearview mirror vibration amplitudes at different vibration frequencies, providing accurate coupling characteristic data for subsequent stiffness correction. This overcomes the blind spots in transmission paths caused by neglecting differences in vibration frequency distribution and the influence of loose connections in conventional designs. The original connection stiffness parameters of the rearview mirror are iteratively corrected using the vibration transmission coupling matrix to obtain target connection stiffness parameters. This allows the connection stiffness value to be adaptively adjusted according to the coupling transmission characteristics. Through multiple iterations, the optimal stiffness range that minimizes mirror vibration amplitude is approximated. This avoids the shortcomings of conventional one-time settings or empirical adjustments that cannot match the vibration transmission characteristics of multiple frequency bands, achieving targeted suppression of rearview mirror vibration at different speeds and vibration frequencies. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1 This is a flowchart illustrating the working steps of a motorcycle rearview mirror anti-shake design method according to the present invention; Figure 2 This is a flowchart of constructing the distribution matrix and determining the transmission threshold in an embodiment of the present invention; Figure 3 This is a flowchart of the iterative correction of the rearview mirror connection stiffness parameters of the present invention; Figure 4 This is a heat map showing the distribution of historical chassis vibration amplitude with varying driving speed ranges and vibration frequencies. Figure 5 This is a graph showing the variation of chassis vibration amplitude with vibration frequency at different driving speed ranges; Figure 6 This is a graph showing the variation of mirror vibration amplitude with vibration frequency under different degrees of looseness; Figure 7 This is a histogram of the distribution of the set of non-zero transit coefficients. Detailed Implementation

[0016] 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.

[0017] Please see Figure 1 As shown, the present invention is a method for anti-shake design of motorcycle rearview mirrors, comprising: This process involves acquiring multiple historical frame vibration amplitudes of a motorcycle at multiple preset vibration frequencies within multiple preset speed ranges, and acquiring multiple historical mirror vibration amplitudes of a rearview mirror at multiple preset vibration frequencies under multiple preset degrees of looseness. A frame vibration distribution matrix is ​​established based on the acquired historical frame vibration amplitudes, and a mirror vibration distribution matrix is ​​established based on the acquired historical mirror vibration amplitudes. The coupling transmission coefficient between the frame vibration distribution matrix and the mirror vibration distribution matrix is ​​calculated to obtain the vibration transmission coupling matrix. The original connection stiffness parameters of the rearview mirror are iteratively corrected using the obtained vibration transmission coupling matrix to obtain the target connection stiffness parameters.

[0018] Example 1 In practice, the first set of acceleration sensing devices is installed at key nodes of the motorcycle frame. These devices are triaxial MEMS accelerometers. While the motorcycle is traveling within a first preset speed range, the peak vibration displacement of the motorcycle frame is collected at multiple preset vibration frequencies. These peak values ​​are then archived according to the preset speed range and preset vibration frequency to obtain multiple historical frame vibration amplitudes. (Appendix) Figure 5 The graphs showing the peak frame vibration displacement as a function of preset vibration frequencies clearly demonstrate the specific numerical correspondences. The preset driving speed ranges include five intervals: 0 km / h to 10 km / h, 10 km / h to 20 km / h, 20 km / h to 30 km / h, 30 km / h to 40 km / h, and 40 km / h to 50 km / h. The preset vibration frequencies range from 10 Hz to 200 Hz. Within the preset driving speed range of 0 km / h to 10 km / h, the peak frame vibration displacement reaches its maximum value of 2.65 mm at a preset vibration frequency of 85 Hz. Within the preset driving speed range of 10 km / h to 20 km / h, the peak frame vibration displacement reaches its maximum value of 2.75 mm at a preset vibration frequency of 70 Hz. Within the preset driving speed range of 20 km / h to 30 km / h, the peak frame vibration displacement reaches its highest value of 3.0 mm at a preset vibration frequency of 80 Hz. Within the preset driving speed range of 30 km / h to 40 km / h, the peak frame vibration displacement reaches its maximum value of 2.85 mm at the preset vibration frequency of 90 Hz. Within the preset driving speed range of 40 km / h to 50 km / h, the peak frame vibration displacement reaches its maximum value of 2.53 mm at the preset vibration frequency of 110 Hz. In all preset driving speed ranges, after the preset vibration frequency exceeds 150 Hz, the peak frame vibration displacement shows a decreasing trend and stabilizes below 1.0 mm.

[0019] In practice, a second set of accelerometers is installed on the edge of the rearview mirror. This second set of accelerometers is a triaxial MEMS accelerometer. When the rearview mirror is at a first preset looseness level, excitation vibrations at multiple preset frequencies are applied to the mirror, and the peak values ​​of the mirror's jitter displacement at each preset vibration frequency are collected. These peak values ​​are then archived according to the preset looseness level and preset vibration frequency to obtain multiple historical mirror jitter amplitudes.

[0020] In some embodiments, the triaxial MEMS accelerometer acquires vibration displacement peak values ​​as follows: the triaxial MEMS accelerometer outputs acceleration time-domain signals in three orthogonal directions, performs a second integration on the acceleration time-domain signals to obtain displacement time-domain signals, and extracts the maximum value of the displacement time-domain signals per unit time as vibration displacement peak value or jitter displacement peak value.

[0021] In practice, the steps of installing the first set of acceleration sensors and collecting data are repeated, along with the steps of installing the second set of acceleration sensors and collecting data, until the frame vibration amplitude and mirror vibration amplitude corresponding to all preset driving speed ranges and all preset looseness are filled. Figure 6 The graph showing the peak value of mirror vibration displacement as a function of preset vibration frequencies demonstrates the response values ​​under different loosening states. The preset loosening levels include five states: fully tightened, Level 1, Level 2, Level 3, and fully loose. In the fully tightened state, the peak mirror vibration displacement reaches its maximum value of 3.5 mm at a preset vibration frequency of 55 Hz. In Level 1, the peak mirror vibration displacement reaches its maximum value of 3.5 mm at a preset vibration frequency of 70 Hz. In Level 2, the peak mirror vibration displacement reaches its maximum value of 3.5 mm at preset vibration frequencies of 65 Hz and 80 Hz. In Level 3, the peak mirror vibration displacement reaches its maximum value of 3.5 mm at preset vibration frequencies of 70 Hz and 85 Hz. In the fully loose state, the peak mirror vibration displacement reaches its maximum value of 3.5 mm at preset vibration frequencies of 75 Hz and 85 Hz. When the preset vibration frequency is within the range of 50 Hz to 90 Hz, the peak values ​​of mirror jitter displacement under each preset looseness level are concentrated in the high range of 2.0 mm to 3.5 mm. When the preset vibration frequency exceeds 160 Hz, the peak values ​​of mirror jitter displacement in all states rapidly decrease to below 0.5 mm.

[0022] In some embodiments, the multiple preset driving speed ranges include continuous speed ranges divided in 10 km / h increments from a standstill to the maximum design speed. The multiple preset looseness levels include five equally spaced looseness grades for the rearview mirror connecting bolts, ranging from fully tightened to fully loose. The multiple preset vibration frequencies include discrete frequency points divided in 5 Hz intervals within the range of 10 Hz to 200 Hz. (Appendix) Figure 4 The diagram illustrates a two-dimensional grid topology distribution of energy intensity, with the horizontal axis representing the preset vibration frequency and the vertical axis representing the preset driving speed range. A color-coded indicator of historical chassis vibration amplitude is attached to the right. Specifically, the horizontal axis of the diagram represents the preset vibration frequency, ranging from 25 Hz to 200 Hz, with a principal coordinate scale every 25 Hz. A distinct vertically highlighted energy band exists within the preset vibration frequency range of 50 Hz to 120 Hz. The vertical axis represents the preset driving speed range, ranging from 0 km / h to 300 km / h, with a principal coordinate scale every 50 km / h. The vertically arranged color-coded indicator on the right defines the linear mapping between energy amplitude and grayscale levels, ranging from 0.0 mm to 3.0 mm, with a component scale every 0.5 mm. Pure black areas correspond to historical chassis vibration amplitudes of 0.0 mm, and pure white areas correspond to historical chassis vibration amplitudes of 3.0 mm. As can be seen from the mesh texture density in the attached figure, within the entire longitudinal projection range of the preset driving speed range of 0 km / h to 300 km / h, the corresponding transverse axis region of 75 Hz to 100 Hz is filled with a large amount of white and light gray mesh. This indicates that within this frequency band, the historical frame vibration amplitude of the motorcycle generally reaches the high-frequency vibration range of 2.0 mm to 3.0 mm. Especially under high-speed driving conditions within the preset driving speed range of 100 km / h to 300 km / h, the grayness of the mesh significantly tends to be pure white, and the historical frame vibration amplitude reaches its maximum peak of 3.0 mm at the intersection of the preset vibration frequencies of 75 Hz and 85 Hz. Conversely, in the edge regions where the preset vibration frequencies are less than 25 Hz or greater than 125 Hz, the mesh in the attached figure appears as a deep black, indicating that in the low-frequency and high-frequency ranges, the historical frame vibration amplitude is basically maintained within a low-slope safe range of 0.0 mm to 0.5 mm.

[0023] Optionally, when the motorcycle is traveling at a first preset speed range, during the process of collecting the peak vibration displacement of the motorcycle frame at multiple preset vibration frequencies, the motorcycle engine speed is recorded synchronously using an order tracking method. The collected time-domain vibration signal is converted to the frequency domain through Fourier transform, and the amplitude corresponding to multiple preset vibration frequencies is extracted in the frequency domain as the peak vibration displacement.

[0024] It is understood that the rearview mirror being at the first preset looseness level means that the pre-tightening torque of the rearview mirror connecting bolts has been adjusted to the torque value corresponding to the predetermined looseness level. The method of applying multiple preset vibration frequencies to the rearview mirror is as follows: the vibrator is connected to the root of the rearview mirror bracket through a top rod, a signal generator generates a sine signal of the corresponding frequency, and the power amplifier drives the vibrator to output vibration.

[0025] Example 2 In the specific implementation, multiple preset driving speed ranges are arranged in ascending order of speed value as the first matrix row index, and multiple preset vibration frequencies are arranged in ascending order of frequency value as the first matrix column index. The historical frame vibration amplitude corresponding to the intersection of each first matrix row index and each first matrix column index is filled into the matrix element to obtain the frame vibration distribution matrix.

[0026] See appendix Figure 2 In some embodiments, the multiple preset driving speed ranges include N speed ranges, where N is a positive integer, and the speed value corresponding to the i-th speed range is denoted as . ,in And satisfy Multiple preset vibration frequencies include M frequency points, where M is a positive integer. The j-th frequency point is denoted as... ,in And satisfy The vibration distribution matrix of the chassis is denoted as... Its dimensions are ,matrix The element in the i-th row and j-th column It is equal to the historical chassis vibration amplitude collected under the conditions of the i-th preset driving speed range and the j-th preset vibration frequency.

[0027] In practice, multiple preset loosening degrees are arranged in ascending order of loosening value and used as the row index of the second matrix. Multiple preset vibration frequencies are arranged in ascending order of frequency value and used as the column index of the second matrix. The historical mirror vibration amplitude corresponding to the intersection of each second matrix row index and each second matrix column index is filled into the matrix element to obtain the mirror vibration distribution matrix.

[0028] In some embodiments, the multiple preset loosening degrees include K loosening levels, where K is a positive integer, and the loosening value corresponding to the kth loosening level is denoted as . ,in And satisfy Multiple preset vibration frequencies are the same as the above M frequency points, denoted as... , The mirror jitter distribution matrix is ​​denoted as... Its dimensions are ,matrix The element in the k-th row and j-th column It is equal to the historical mirror vibration amplitude collected under the conditions of the kth preset looseness level and the jth preset vibration frequency.

[0029] In practice, the frame vibration distribution matrix is ​​normalized to obtain a normalized frame vibration distribution matrix, and the mirror vibration distribution matrix is ​​normalized to obtain a normalized mirror vibration distribution matrix.

[0030] Optionally, the normalization process uses maximum value normalization. This applies to the chassis vibration distribution matrix. Extracting the matrix The maximum value of all elements in the set is denoted as . The normalized frame vibration distribution matrix is ​​denoted as... Its dimensions and Same, matrix The element in the i-th row and j-th column Calculate according to the following formula: ; in, For matrix The element in the i-th row and j-th column, For matrix The maximum value of all elements in the matrix. For the mirror jitter distribution matrix. Extracting the matrix The maximum value of all elements in the set is denoted as . The normalized mirror jitter distribution matrix is ​​denoted as... Its dimensions and Same, matrix The element in the k-th row and j-th column Calculate according to the following formula: ; in, For matrix The element in the k-th row and j-th column, For matrix The maximum value of all elements in the set.

[0031] In practice, the preset transmission threshold is determined by the median of the statistical distribution of the vibration transmission coefficient.

[0032] In some embodiments, the statistical distribution of the vibration transmission coefficient is obtained by: normalizing the frame vibration distribution matrix. and normalized mirror jitter distribution matrix Each column in the table corresponds to the same preset vibration frequency. For the j-th preset vibration frequency, the set of vibration transmission coefficients at that frequency is calculated. ,in , This is the index of the preset driving speed range corresponding to the j-th preset vibration frequency. Iterate through all preset looseness levels. Combine all vibration transmission coefficients calculated at all preset vibration frequencies into a one-dimensional array as a statistical distribution sample of the vibration transmission coefficients. Sort all values ​​in the statistical distribution sample in ascending order, and take the value in the middle position after sorting as the median. Determine the median value as the preset transmission threshold.

[0033] It can be understood that the median of the statistical distribution of vibration transmissibility coefficients is the value in the middle of the sequence after all vibration transmissibility coefficients are arranged in ascending order. When the number of samples in the statistical distribution is even, the median is the arithmetic mean of the two middle values. Figure 7 The statistical distribution chart and cumulative distribution curve of the transmission coefficients displayed can quantify the core statistical indicators of vibration transmission characteristics. The total number of samples for the statistical distribution of transmission coefficients is 195. The arithmetic mean of all samples is 1.034. The median of all samples is 1.014. The statistical standard deviation of all samples is 0.197. The median value of 1.014 is determined as the preset transmission threshold, thus applying the central tendency reflected in the histogram and cumulative distribution curve to the benchmark judgment of stiffness iteration correction.

[0034] Example 3 See appendix Figure 3 In practical implementation, the normalized frame vibration distribution matrix is ​​defined as follows: Normalized frame vibration distribution matrix The dimension is ,in The number of preset driving speed ranges, The number of preset vibration frequencies. The normalized mirror vibration distribution matrix is ​​defined as follows: Normalized mirror jitter distribution matrix The dimension is ,in The preset number of loosening levels.

[0035] In practical implementation, the frame autocorrelation matrix is ​​calculated. Frame autocorrelation matrix The dimension is , Normalized chassis vibration distribution matrix The transpose of . Calculate the cross-correlation matrix between the frame and the mirror. Cross-correlation matrix of the frame and the mirror The dimension is .

[0036] In practical implementation, the initial coupling transfer coefficient matrix is ​​calculated. Initial coupling transfer coefficient matrix elements Obtained from the following formula: ; in, It is the initial coupling transfer coefficient matrix The Middle line, number Column elements, The range of values ​​is to , The range of values ​​is to ; It is the cross-correlation matrix between the frame and the mirror. The Middle line, number Column elements; It is the frame autocorrelation matrix The first diagonal of the middle main The elements are the frame autocorrelation matrix. The Middle Line 1 Column elements; A very small positive number pre-defined to prevent division by zero errors. The value is ; This is the function for finding the maximum value.

[0037] In some embodiments, The value is determined based on: Set to less than all possible non-zero values The smallest order of magnitude of the absolute value of a numerical value, which is also greater than the smallest normalized number of a double-precision floating-point number. It can avoid division results where the denominator is zero in common numerical calculations without affecting the significant values.

[0038] In practical implementation, the initial coupling transfer coefficient matrix will be... All coefficients less than a preset transmission threshold are set to zero, while all coefficients greater than or equal to the preset transmission threshold remain unchanged, thus obtaining the vibration transmission coupling matrix. .

[0039] In practice, the initial preload of the original connecting bolts of the rearview mirror is converted into the original connection stiffness parameter, and this parameter is used as the current iteration stiffness parameter. The elastic modulus of the bolt material, the effective load-bearing cross-sectional area of ​​the bolt, and the initial preload elongation of the bolt are obtained. The elastic modulus of the bolt material is multiplied by the effective load-bearing cross-sectional area to obtain an intermediate product, which is then divided by the initial preload elongation to obtain the original connection stiffness parameter. This parameter is then assigned to the current iteration variable to obtain the current iteration stiffness parameter.

[0040] In some embodiments, the elastic modulus of the bolt material is denoted as . Bolt material elastic modulus The unit is megapascal; the effective load-bearing cross-sectional area of ​​the bolt is denoted as... Effective bearing cross-sectional area of ​​bolts The unit is square millimeters; the initial preload elongation of the bolt is denoted as... Initial preload elongation of bolt The unit is millimeters. Original connection stiffness parameters. Calculate using the following formula: ; in, This is the intermediate product result. The original connection stiffness parameters... Assigned to the stiffness parameter of the current iteration ,Right now .

[0041] In practical implementation, from the vibration transmission coupling matrix Extract all non-zero elements to form a set of non-zero transit coefficients. From the set of non-zero transitivity coefficients Find the maximum value in the range and use it as the maximum transmission coefficient. Let the current iteration stiffness parameter be denoted as... The stiffness correction step size is calculated using the following formula. : ; in, The preset damping factor. The value range is (0,1). In some embodiments, the preset damping factor The value is 0.3. This is the preset damping factor. The basis for setting it to 0.3 is that during the iterative correction process, a damping factor of 0.3 can provide sufficient correction speed while ensuring convergence stability. This value was determined by numerical simulation experiments on the typical stiffness parameter range of the rearview mirror connection system.

[0042] In practice, the updated iterative stiffness parameter is obtained by subtracting the stiffness correction step size from the current iterative stiffness parameter. The current iterative stiffness parameter is defined as... superscript Indicates the first The next iteration; the stiffness correction step size is defined as... The updated iterative stiffness parameters are calculated using the following formula. : ; Calculation results Used as the current iteration stiffness parameter for the next iteration.

[0043] In practice, it is determined whether the updated iterative stiffness parameter is less than a preset minimum stiffness threshold. If the updated iterative stiffness parameter is less than the preset minimum stiffness threshold, the current iterative stiffness parameter is used as the target connection stiffness parameter. If the updated iterative stiffness parameter is greater than or equal to the preset minimum stiffness threshold, the updated iterative stiffness parameter is used as the new current iterative stiffness parameter, and the stiffness correction step size is recalculated. Iterative correction continues until the number of iterations reaches the preset maximum number of iterations, and the iterative stiffness parameter obtained in the last iteration is used as the target connection stiffness parameter.

[0044] In some embodiments, the preset minimum stiffness threshold is determined based on the equivalent stiffness of the rearview mirror connecting bolts in a fully loosened state, and the preset minimum stiffness threshold is set to 100 Newtons per millimeter. The preset maximum number of iterations is set to 20.

[0045] Example 4 In practice, after obtaining the target connection stiffness parameters, the target preload torque of the connecting bolts is calculated based on these parameters, and the connecting bolts of the rearview mirror are tightened according to the target preload torque. (Obtaining the target connection stiffness parameters) The thread pitch diameter of the rearview mirror connecting bolt The coefficient of friction between the bolt and the connecting base and the elastic modulus of the bolt material Calculate the target preload of the connecting bolts. : ; in, The initial deformation design value for the connection system. The unit is millimeters. The value is obtained by measuring the gap between the bolt head and the mating surface of the connected parts when the preload of the rearview mirror connecting bolt is zero, or it can be read directly from the design drawings. Based on the target preload... Calculate the target preload torque : ; in, The mean diameter of the thread on the rearview mirror connecting bolt. The unit is millimeters; The coefficient of friction between the bolt and the connecting base. It is a dimensionless number, with a value range of 0.10 to 0.20; For thread helix angle, The unit is radians; This is the tangent of the thread helix angle, which is calculated based on the nominal diameter and pitch of the bolt. The calculation formula is: ,in For pitch, and The units are all millimeters; Pi, with a value of 3.1415926535. Use a torque wrench to apply the calculated target preload torque. Tighten the connecting bolts of the rearview mirror.

[0046] In practice, reflective markers are affixed to the surface of the tightened rearview mirror, and multiple actual vibration trajectory images of the markers are continuously captured using a high-speed camera while the motorcycle is in motion. The maximum actual vibration amplitude of the mirror surface is extracted from these images, and it is determined whether this amplitude is less than a preset anti-vibration threshold. If the maximum vibration amplitude is greater than or equal to the preset anti-vibration threshold, multiple historical frame vibration amplitudes and multiple historical mirror vibration amplitudes are reacquired, and the vibration transmission coupling matrix is ​​recalculated to perform a secondary correction on the target connection stiffness parameters.

[0047] In some embodiments, the sampling frequency of the high-speed camera is set to 1000 frames per second, and the reflective markers are circular reflective patches with a diameter of 3 mm. The preset anti-shake qualification threshold is 2 mm, which is based on the maximum permissible amplitude of mirror shake in motorcycle rearview mirror regulations.

[0048] In practical implementation, before iteratively correcting the original connection stiffness parameters of the rearview mirror using the vibration transmission coupling matrix, the mirror mass parameters and mirror moment of inertia parameters of the rearview mirror surface, as well as the equivalent length parameters and section modulus parameters of the rearview mirror bracket, are obtained. The mass of the rearview mirror surface is defined as... The quality of the rearview mirror surface The unit is kilogram; the moment of inertia of the rearview mirror surface on its centroidal axis is defined as... The moment of inertia of the rearview mirror mirror on its center of mass axis The unit is kilogram-square meter; the equivalent length of the rearview mirror bracket is defined as... The equivalent length of the rearview mirror bracket The unit is meters; the section modulus of the rearview mirror bracket is defined as... The section modulus of the rearview mirror bracket The unit is cubic meters. The estimated natural frequency of the rearview mirror system is calculated using the following formula. : ; in, The structural coefficients related to the rearview mirror mounting method, It is a dimensionless number, obtained by fitting pre-calibrated experimental data; Pi, with a value of 3.1415926535; This represents the square root operation. In some embodiments, The method for obtaining the value is as follows: Select at least three standard rearview mirror assemblies with known mass and stiffness, measure the actual natural frequency of each assembly, and substitute the measured natural frequency into the above formula to solve for the value. Values ​​obtained from multiple inverse solutions Perform linear regression on the values, and use the constant term obtained from the regression as... The value of .

[0049] In practical implementation, the estimated value of the natural frequency is determined. Is it related to the dominant vibration frequency of the motorcycle engine? The difference is less than the preset frequency avoidance threshold. If the natural frequency is estimated... With the dominant vibration frequency of the engine The difference is less than the preset frequency avoidance threshold. Then, the step of iteratively correcting the original connection stiffness parameters of the rearview mirror using the vibration transmission coupling matrix is ​​performed. If the estimated natural frequency value... With the dominant vibration frequency of the engine The difference is greater than or equal to the preset frequency avoidance threshold. If so, the original connection stiffness parameters are directly output as the target connection stiffness parameters.

[0050] In some embodiments, the dominant vibration frequency of the engine The vibration acceleration signal of the engine block surface was obtained by measuring the vibration acceleration signal at intervals of 200 revolutions per minute within the range of the motorcycle engine's idle speed to its maximum speed. A Fourier transform was performed on the vibration acceleration signal at each speed, and the frequency component with the largest amplitude was extracted as the dominant vibration frequency at that speed. The minimum value of the dominant vibration frequencies across all speeds was taken as the engine's dominant vibration frequency. Preset frequency avoidance threshold The value is set at 5 Hz. This value is based on the requirement in engineering design that the natural frequency and the excitation frequency should be at least 15% apart in order to avoid resonance. The value is determined by rounding down 15% of the engine’s dominant vibration frequency range (20 Hz to 100 Hz).

[0051] Example 5 In practice, after obtaining the target connection stiffness parameters, these parameters are substituted into the frame vibration distribution matrices corresponding to multiple different motorcycle models to calculate the predicted vibration amplitude of the rearview mirror for each model. The predicted vibration amplitude of the rearview mirror for each motorcycle model is then compared with the preset vibration tolerance threshold for that model to identify a set of risky models whose predicted vibration amplitude exceeds the preset vibration tolerance threshold.

[0052] In some embodiments, the frame vibration distribution matrices corresponding to multiple different motorcycle models are obtained as follows: For each motorcycle model, the historical frame vibration amplitude of that model is obtained according to the methods described in Embodiments 1 and 2, and a corresponding frame vibration distribution matrix is ​​established. The method for calculating the predicted rearview mirror shake amplitude by substituting the target connection stiffness parameter into the frame vibration distribution matrix corresponding to each motorcycle model is as follows: For any model, the maximum value element in the frame vibration distribution matrix corresponding to that model is extracted, and this maximum value element is multiplied by the reciprocal of the target connection stiffness parameter. The product obtained is used as the predicted rearview mirror shake amplitude for that model. The preset shake tolerance threshold is 2.5 mm. This value is based on the premise that a clear rear view can be guaranteed when the motorcycle rearview mirror mirror shake does not exceed 2.5 mm within the commonly used driving speed range.

[0053] In practice, for each risk vehicle in the risk vehicle set, the unique frame structure features of that risk vehicle are extracted, and the target connection stiffness parameters are finely adjusted according to the unique frame structure features to obtain the personalized connection stiffness parameters of that risk vehicle.

[0054] In some embodiments, the unique frame structure features include the frame main beam cross-sectional shape factor, the frame material elastic modulus, and the number of local reinforcing ribs at the rearview mirror mounting points for the risk vehicle model. The method for personalized fine-tuning of the target connection stiffness parameters based on these unique frame structure features is as follows: The frame main beam cross-sectional shape factor, the frame material elastic modulus, and the number of local reinforcing ribs at the rearview mirror mounting points are normalized, multiplied by their corresponding weighting coefficients, and summed to obtain a fine-tuning factor. The target connection stiffness parameters are then multiplied by this fine-tuning factor to obtain the personalized connection stiffness parameters for the risk vehicle model. The frame main beam cross-sectional shape factor is set as follows: 1.0 for rectangular cross-sections, 0.8 for circular cross-sections, and 0.9 for elliptical cross-sections; the frame material elastic modulus is taken as the measured value; the fine-tuning factor increases by 0.02 for each additional local reinforcing rib at the rearview mirror mounting points.

[0055] In practice, after obtaining the vibration transmission coupling matrix, each transmission coefficient in the vibration transmission coupling matrix is ​​divided into high transmission segment, medium transmission segment and low transmission segment according to its numerical value.

[0056] In some embodiments, the method for dividing each transmission coefficient in the vibration transmission coupling matrix into high, medium, and low transmission segments according to its numerical value is as follows: extract the minimum and maximum values ​​of all non-zero transmission coefficients in the vibration transmission coupling matrix, calculate the difference between the minimum and maximum values, divide the difference into three equal intervals: the interval with the smallest value is the low transmission segment, the interval with the middle value is the medium transmission segment, and the interval with the largest value is the high transmission segment. Alternatively, transmission coefficients with values ​​less than 0.3 are divided into low transmission segments, transmission coefficients with values ​​greater than or equal to 0.3 and less than 0.7 are divided into medium transmission segments, and transmission coefficients with values ​​greater than or equal to 0.7 are divided into high transmission segments.

[0057] In practice, the preset vibration frequencies corresponding to the transmission coefficients in the high transmission range are statistically analyzed to form a high-risk frequency set, and the preset vibration frequencies corresponding to the transmission coefficients in the medium transmission range are statistically analyzed to form a medium-risk frequency set.

[0058] In some embodiments, the method for calculating the preset vibration frequency corresponding to the transmission coefficient in the high transmission range is as follows: traverse each non-zero transmission coefficient in the vibration transmission coupling matrix, determine whether the transmission coefficient belongs to the high transmission range, and if it belongs to the high transmission range, add the preset vibration frequency value corresponding to the column containing the transmission coefficient to the high-risk frequency set. The method for calculating the preset vibration frequency corresponding to the transmission coefficient in the medium transmission range is as follows: traverse each non-zero transmission coefficient in the vibration transmission coupling matrix, determine whether the transmission coefficient belongs to the medium transmission range, and if it belongs to the medium transmission range, add the preset vibration frequency value corresponding to the column containing the transmission coefficient to the medium-risk frequency set.

[0059] In practice, a first set of damping material attachment position indicators is generated based on the high-risk frequency set, and a second set of damping material attachment thickness indicators is generated based on the medium-risk frequency set.

[0060] In some embodiments, the method for generating the first set of damping material attachment position indicators based on the high-risk frequency set is as follows: The frequency values ​​in the high-risk frequency set are arranged in ascending order. For each frequency value, the corresponding half-wavelength of vibration is calculated. Starting from the root of the rearview mirror bracket, the damping material attachment point is marked at the half-wavelength position along the bracket's extension direction. All marked points constitute the first set of damping material attachment position indicators. The formula for calculating the half-wavelength of vibration is that half-wavelength equals the speed of sound divided by twice the frequency value, where the speed of sound is taken as 340 meters per second. The method for generating the second set of damping material attachment thickness indicators based on the medium-risk frequency set is as follows: For each frequency value in the medium-risk frequency set, the base thickness of the damping material is calculated according to the formula that thickness equals the speed of sound divided by four times the frequency value. The calculated base thickness is used as the second set of damping material attachment thickness indicators.

[0061] In practice, the first set of damping material attachment position indicators and the second set of damping material attachment thickness indicators are combined and output as an additional damping treatment scheme for the rearview mirror.

[0062] In some embodiments, the output is merged as follows: each attachment point in the first set of damping material attachment position indicators is paired with the thickness value of the corresponding frequency in the second set of damping material attachment thickness indicators to generate a list containing attachment position coordinates and attachment thickness, and the list is output as an additional damping processing scheme.

[0063] 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. A method for designing anti-shake features for motorcycle rearview mirrors, characterized in that, The method includes: The system acquires multiple historical frame vibration amplitude values ​​of a motorcycle at multiple preset vibration frequencies within multiple preset driving speed ranges, and acquires multiple historical mirror vibration amplitude values ​​of a rearview mirror at multiple preset vibration frequencies under multiple preset looseness levels. A frame vibration distribution matrix is ​​established based on the multiple historical frame vibration amplitudes, and a mirror vibration distribution matrix is ​​established based on the multiple historical mirror vibration amplitudes. Calculate the coupling transmission coefficient between the frame vibration distribution matrix and the mirror vibration distribution matrix to obtain the vibration transmission coupling matrix, including: Multiply the transpose of the normalized frame vibration distribution matrix with the normalized frame vibration distribution matrix to obtain the frame autocorrelation matrix; Multiply the normalized mirror vibration distribution matrix with the transpose of the normalized frame vibration distribution matrix to obtain the cross-correlation matrix between the frame and the mirror. Divide each element in the cross-correlation matrix by the element at the corresponding diagonal position in the frame autocorrelation matrix to obtain the initial coupling transfer coefficient matrix; Set all coefficients in the initial coupling transmission coefficient matrix that are less than a preset transmission threshold to zero, and keep all coefficients that are greater than or equal to the preset transmission threshold unchanged to obtain the vibration transmission coupling matrix. The original connection stiffness parameters of the rearview mirror are iteratively corrected using the vibration transmission coupling matrix to obtain the target connection stiffness parameters.

2. The motorcycle rearview mirror anti-shake design method according to claim 1, characterized in that, Acquire multiple historical frame vibration amplitudes of the motorcycle at multiple preset vibration frequencies within multiple preset speed ranges, and acquire multiple historical mirror vibration amplitudes of the rearview mirror at multiple preset vibration frequencies under multiple preset looseness levels, including: S1: Install a first set of acceleration sensing devices at key nodes of the motorcycle frame. When the motorcycle is traveling in a first preset speed range, collect the peak vibration displacement of the motorcycle frame at the multiple preset vibration frequencies. Archive the peak vibration displacement according to the preset speed range and preset vibration frequency to obtain the multiple historical frame vibration amplitudes. S2: Install a second set of acceleration sensing devices on the edge of the rearview mirror, and when the rearview mirror is at a first preset looseness, apply the excitation vibration of the rearview mirror at the multiple preset vibration frequencies, collect the peak value of the shaking displacement of the rearview mirror surface at the multiple preset vibration frequencies, and archive the peak value of the shaking displacement according to the preset looseness and preset vibration frequency to obtain the multiple historical mirror surface shaking amplitude values. S3: Traverse the multiple preset driving speed ranges and multiple preset looseness levels, repeating steps S1 and S2 until the frame vibration amplitude and mirror vibration amplitude corresponding to all preset driving speed ranges and all preset looseness levels are filled.

3. The motorcycle rearview mirror anti-shake design method according to claim 2, characterized in that, The first set of acceleration sensing devices and the second set of acceleration sensing devices are triaxial MEMS accelerometers.

4. The motorcycle rearview mirror anti-shake design method according to claim 1, characterized in that, A chassis vibration distribution matrix is ​​established based on the multiple historical chassis vibration amplitudes, and a mirror vibration distribution matrix is ​​established based on the multiple historical mirror vibration amplitudes, including: The multiple preset driving speed ranges are arranged in ascending order of speed value as the first matrix row index, and the multiple preset vibration frequencies are arranged in ascending order of frequency value as the first matrix column index. The historical frame vibration amplitude corresponding to the intersection of each first matrix row index and each first matrix column index is filled into the matrix element to obtain the frame vibration distribution matrix. The multiple preset loosening degrees are arranged in ascending order of loosening value and used as the row index of the second matrix. The multiple preset vibration frequencies are arranged in ascending order of frequency value and used as the column index of the second matrix. The historical mirror vibration amplitude corresponding to the intersection of each second matrix row index and each second matrix column index is filled into the matrix element to obtain the mirror vibration distribution matrix. The frame vibration distribution matrix is ​​normalized to obtain a normalized frame vibration distribution matrix, and the mirror vibration distribution matrix is ​​normalized to obtain a normalized mirror vibration distribution matrix.

5. The motorcycle rearview mirror anti-shake design method according to claim 4, characterized in that, The preset transmission threshold is determined by the median of the statistical distribution of the vibration transmission coefficient.

6. The motorcycle rearview mirror anti-shake design method according to claim 5, characterized in that, The original connection stiffness parameters of the rearview mirror are iteratively corrected using the vibration transmission coupling matrix to obtain the target connection stiffness parameters, including: The initial preload of the original connecting bolts of the rearview mirror is converted into the original connection stiffness parameter, and the original connection stiffness parameter is used as the current iteration stiffness parameter. The stiffness correction step size is obtained by multiplying the current iteration stiffness parameter with the maximum transmission coefficient in the vibration transmission coupling matrix. Subtract the stiffness correction step size from the current iterative stiffness parameter to obtain the updated iterative stiffness parameter; Determine whether the updated iterative stiffness parameter is less than a preset minimum stiffness threshold. If the updated iterative stiffness parameter is less than the preset minimum stiffness threshold, then use the current iterative stiffness parameter as the target connection stiffness parameter. If the updated iterative stiffness parameter is greater than or equal to the preset minimum stiffness threshold, then the updated iterative stiffness parameter is used as the new current iterative stiffness parameter, and the stiffness correction step size is recalculated. Iterative correction continues until the number of iterations reaches the preset maximum number of iterations. The iterative stiffness parameter obtained in the last iteration is used as the target connection stiffness parameter.

7. The motorcycle rearview mirror anti-shake design method according to claim 6, characterized in that, The initial preload of the original connecting bolts of the rearview mirror is converted into the original connection stiffness parameter, and the original connection stiffness parameter is used as the current iteration stiffness parameter, including: Obtain the elastic modulus of the bolt material, the effective load-bearing cross-sectional area of ​​the bolt, and the initial preload elongation of the bolt for the rearview mirror connection bolt; Multiply the elastic modulus of the bolt material by the effective bearing cross-sectional area of ​​the bolt to obtain an intermediate product result, and then divide the intermediate product result by the initial preload elongation of the bolt to obtain the original connection stiffness parameter. The original connection stiffness parameter is assigned to the current iteration variable to obtain the current iteration stiffness parameter.

8. The motorcycle rearview mirror anti-shake design method according to claim 1, characterized in that, After obtaining the target connection stiffness parameters, the method further includes: The target preload torque of the connecting bolts is calculated by back-calculating the target connection stiffness parameters, and the connecting bolts of the rearview mirror are tightened according to the target preload torque. Reflective markers were affixed to the surface of the rearview mirror after it was secured, and multiple actual shaking trajectory images of the reflective markers were continuously captured using a high-speed camera while the motorcycle was in motion. Extract the actual maximum jitter amplitude of the mirror from the multiple actual jitter trajectory images, and determine whether the actual maximum jitter amplitude of the mirror is less than the preset anti-shake qualified threshold; If the actual maximum vibration amplitude of the mirror surface is greater than or equal to the preset anti-vibration qualification threshold, then multiple historical frame vibration amplitudes and multiple historical mirror surface vibration amplitudes are reacquired, and the vibration transmission coupling matrix is ​​recalculated to perform secondary correction on the target connection stiffness parameters.

9. The motorcycle rearview mirror anti-shake design method according to claim 1, characterized in that, Before iteratively correcting the original connection stiffness parameters of the rearview mirror using the vibration transmission coupling matrix, the method further includes: Obtain the mirror mass parameters and mirror moment of inertia parameters of the rearview mirror surface, as well as the equivalent length parameters and cross-sectional modulus parameters of the rearview mirror bracket; Multiply the mirror quality parameter and the mirror moment of inertia parameter, and then divide by the product of the bracket equivalent length parameter and the bracket section modulus parameter to obtain the estimated value of the natural frequency of the rearview mirror system. Determine whether the difference between the estimated natural frequency and the dominant vibration frequency of the motorcycle engine is less than a preset frequency avoidance threshold. If the difference between the estimated natural frequency and the dominant vibration frequency of the engine is less than the preset frequency avoidance threshold, then the step of iteratively correcting the original connection stiffness parameters of the rearview mirror using the vibration transmission coupling matrix is ​​executed. If the difference between the estimated natural frequency and the dominant vibration frequency of the engine is greater than or equal to the preset frequency avoidance threshold, the original connection stiffness parameter is directly output as the target connection stiffness parameter.

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