A method for identifying abnormal vibration of a tire by color difference of a tire tread

Abstract

The present application relates to the technical field of tire detection, and more particularly to a method for identifying abnormal vibration of tire through color difference of tire tread, comprising: generating a point cloud graph; under a first rotating speed, generating a first tire surface height point cloud graph; generating a first visual point cloud graph and determining an abnormal vibration level; dividing a detection interval, each detection interval being configured with n detection point sets; under a second rotating speed, generating a second tire surface height point cloud graph; reducing the tire rotating speed at a preset rate, calculating a stability score and determining whether the stability of the detection device meets the requirements; in response to meeting the requirements, rendering the tire surface to generate a second visual point cloud graph and determining the abnormal vibration level. The present application calculates the height difference of the tire surface height at each detection point position, and renders the tire surface according to the height difference and a preset color matching mechanism, so that the vibration condition caused by the tire surface height can be intuitively and visually displayed.

Description

Technical Field

[0001] This invention relates to the field of tire inspection technology, and in particular to a method for identifying abnormal tire vibrations by measuring the color difference of the tire tread. Background Technology

[0002] With economic development and a continuous increase in car ownership, the stability requirements of tires, as the bridge between the car and the ground, are increasing. During vehicle operation, tire vibration generates noise, especially with the rise of new energy vehicles in recent years. Electric motors, due to their lower vibration and noise characteristics compared to engines, are more sensitive to noise generated by tire vibration. Furthermore, statistics show that approximately 60% of vehicle noises and steering wheel vibrations are caused by abnormal tire vibration. Therefore, the need for monitoring tire vibration during driving is growing.

[0003] Currently, there are three main methods for detecting abnormal tire vibration: 1) Real-vehicle sensor detection: This method requires attaching numerous sensors to the tire and simultaneously collecting a large amount of data at high speeds, resulting in high power consumption. Furthermore, the sensors are prone to malfunction due to prolonged exposure to centrifugal force, leading to high maintenance costs. 2) Bench uniformity testing: This method simulates tire rolling on a test bench. At high speeds, the bench needs to collect data from all surface points at once, which can easily lead to missed or redundant data collection, resulting in low accuracy. 3) Traditional visual inspection: This method uses laser scanning to generate point cloud maps, but collecting data from all points at high speeds causes a sharp increase in the power consumption of the detection device.

[0004] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0005] The purpose of this invention is to provide a method for identifying abnormal tire vibration by detecting the color difference of the tire tread. This addresses the problems of existing technologies, such as: the real-vehicle sensor detection method, which requires attaching numerous sensors to the tire and simultaneously collecting a large amount of data at high speeds, resulting in high power consumption and sensor malfunction due to long-term centrifugal force, leading to high maintenance costs; the bench uniformity test method, which simulates tire rolling on a test bench, requires simultaneous collection of data from all surface points at high speeds, which can easily result in missed or redundant data collection and low accuracy; and the traditional visual inspection method, which uses laser scanning to generate point cloud maps, suffers from a sudden increase in power consumption of the detection device when collecting data from all points at high speeds.

[0006] This invention provides a method for identifying abnormal tire vibration by measuring the color difference in the tire tread, comprising:

[0007] Obtain basic tire parameters, set several detection points based on the basic tire parameters, and generate a point cloud map;

[0008] The tire surface height at each detection point is collected at the first rotation speed, and a first tire surface height point cloud map is generated.

[0009] Based on the first tire surface height point cloud map and the preset color matching mechanism, the tire surface is rendered to generate a first visual point cloud map, and the abnormal vibration level of the tire at the first rotational speed is determined according to the first preset standard and the first visual point cloud map.

[0010] In response to the abnormal vibration level of the tire at the first rotational speed being level one vibration, the point cloud map is divided into several detection intervals along the tire circumference with a preset length, and each detection interval is configured with n mutually independent sets of detection points.

[0011] The first set of detection points in each detection interval is collected at the second rotation speed. After the first set of detection points is collected, the second set of detection points in each detection interval is collected, and so on, until all sets of detection points are collected. A second tire surface height point cloud map is generated based on the measured tire surface height.

[0012] The tire speed is reduced at a preset rate, and the tire surface height within the first set of detection points is continuously collected within a preset time. The change in tire surface height is obtained to calculate the stability score, and the stability of the detection device is determined based on the stability score.

[0013] In response to the stability of the detection device meeting the requirements, the tire surface is rendered to generate a second visual point cloud map based on the second tire surface height point cloud map and the preset color matching mechanism.

[0014] The abnormal vibration level of the tire at the second rotational speed is determined by combining the second preset standard;

[0015] Wherein: the first rotational speed is less than the second rotational speed.

[0016] As a preferred technical solution for a method of identifying abnormal tire vibration through tire tread color difference, the step of acquiring basic tire parameters, setting several detection points based on the basic tire parameters, and generating a point cloud map includes:

[0017] An initial point is selected at the center of the tire crown; this initial point is used to reference whether the tire rotates one revolution during the tire inspection process.

[0018] Starting from the initial point, several detection points are evenly distributed along the tire circumference at a first interval, and several detection points are evenly distributed along the tire transverse direction at a second interval.

[0019] The point cloud map is generated based on the aforementioned detection points.

[0020] As a preferred technical solution for a method of identifying abnormal tire vibration by means of tire tread color difference, the step of acquiring the tire surface height at each detection point at a first rotational speed and generating a first tire surface height point cloud map includes:

[0021] Obtain the distance between detection points along the tire circumference and record it as the circumferential distance;

[0022] The detection frequency of the detection device is adjusted according to the circumferential spacing and the first rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference.

[0023] The tire surface height at each detection point is collected at the first rotational speed;

[0024] The tire surface height at each detection point is matched with the point cloud image to generate a first tire surface height point cloud map.

[0025] As a preferred technical solution for identifying abnormal tire vibration by the color difference of the tire tread, the point cloud map is divided into several detection intervals along the tire circumference with a preset length. Each detection interval is configured with n independent sets of detection points, and each set of detection points includes several detection points in the same lateral direction.

[0026] The preset length is an integer multiple of the first spacing.

[0027] As a preferred technical solution for a method of identifying abnormal tire vibration by detecting tire tread color difference, the method involves acquiring a first set of detection points for each detection interval at a second rotational speed. After acquiring the first set of detection points, a second set of detection points for each detection interval is acquired, and so on, until all sets of detection points have been acquired. A second tire surface height point cloud map is then generated based on the measured tire surface height, including:

[0028] The detection frequency of the detection device is adjusted according to the circumferential spacing and the second rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference.

[0029] In response to the start of the detection, starting from the initial point, the first set of detection points in all detection intervals is collected within one revolution of the tire.

[0030] In response to the completion of the first set of detection points in all detection intervals, a new initial point is selected in the next detection interval of the current initial point. Starting from the newly selected initial point, the second set of detection points in all detection intervals is collected within one revolution of the tire. This process continues until all sets of detection points have been detected.

[0031] Wherein: the distance between the reselected initial point and the current initial point is the preset length.

[0032] As a preferred technical solution for a method of identifying abnormal tire vibration through tire tread color difference, the step of obtaining changes in tire surface height and calculating a stability score includes:

[0033] Within a preset time, the tire speed is reduced at a preset rate, and the tire surface height and lateral offset corresponding to each detection point in the first set of detection points are continuously collected.

[0034] For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the surface height. The tire surface height curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed tire surface height curve is obtained and recorded as the height curvature.

[0035] For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the lateral offset. The tire lateral offset curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed lateral offset curve is obtained and recorded as the lateral curvature.

[0036] During the tire speed reduction process, the height curvature and the lateral curvature corresponding to each preset tire speed are assigned corresponding weight coefficients. The sum of the products of the height curvature and the lateral curvature and the corresponding weight coefficients is calculated and recorded as the stability score corresponding to each tire speed.

[0037] Stability variation curves are plotted based on tire speed and corresponding stability scores.

[0038] As a preferred technical solution for identifying abnormal tire vibration by means of tire tread color difference, the stability of the detection device is determined based on the stability score. In response to the situation where the scores corresponding to the points on the stability change curve are all within the score range during the tire speed reduction process, the stability of the detection device is determined to meet the requirements.

[0039] As a preferred technical solution for identifying abnormal tire vibration by means of tire tread color difference, the preset color matching mechanism divides the tire surface height into five intervals according to six interval points, and determines the color of each interval point as one of the six colors: black, blue, green, red, yellow, and white. The change in tire surface height is represented by the color gradient between the interval points.

[0040] As a preferred technical solution for identifying abnormal tire vibration by means of tire tread color difference, the basic tire parameters include: circumference, width, and tire model.

[0041] As a preferred technical solution for identifying abnormal tire vibration by tire tread color difference, in response to the existence of missing data in the detection point set, the data acquisition of subsequent detection points is immediately stopped, and the detection point set is re-acquired starting from the current initial point and increasing the laser power according to the preset amplitude.

[0042] In response to the fact that the power adjustment was performed twice and there was a data gap in the detection point set, it was determined that there was damage in the area corresponding to the detection point set, and the detection point set was marked.

[0043] Compared with existing technologies, the beneficial effect of this invention lies in that, by detecting the tire surface height, the changes in tire surface height during tire rotation are calculated. These changes in tire surface height during rotation generate periodic uneven centrifugal force, which in turn translates into vibration. Therefore, this embodiment of the invention calculates the height difference of the tire surface at each detection point, and based on the height difference and a preset color matching mechanism, renders the tire surface to generate a visual point cloud map, thereby allowing the vibration caused by the tire surface height to be displayed intuitively and visually.

[0044] Furthermore, this invention divides the tire surface height point cloud map into several detection intervals along the tire circumference. Each detection interval is configured with four independent sets of detection points, and each set of detection points includes several detection points located in the same lateral direction. This ensures that only the first set of detection points in different detection intervals is collected for each rotation of the tire. After one rotation, the second set of detection points in different detection intervals is collected. This eliminates the need for the detection device to collect tire surface height data from all detection points within one rotation of the tire, thereby reducing the power requirement of the detection device during the detection process. Moreover, due to the initial point setting and the matching of rotation speed and scanning frequency, the accuracy and completeness of the detection point data collection are guaranteed, providing an accurate data foundation for subsequent height difference calculation and tire surface rendering. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the steps of a method for identifying abnormal tire vibrations based on tire tread color difference, as described in an embodiment of the present invention. Detailed Implementation

[0046] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0048] Please see Figure 1 The diagram shown is a flowchart illustrating the steps of a method for identifying abnormal tire vibrations based on tire tread color difference according to an embodiment of the present invention, including:

[0049] Step S1: Obtain basic tire parameters, set several detection points based on the basic tire parameters, and generate a point cloud map.

[0050] Step S2: Collect the tire surface height at each detection point at the first rotation speed and generate a first tire surface height point cloud map;

[0051] Step S3: Render the tire surface to generate a first visual point cloud map based on the first tire surface height point cloud map and the preset color matching mechanism; determine the abnormal vibration level of the tire at the first rotational speed based on the first preset standard and the first visual point cloud map.

[0052] Step S4: In response to the abnormal vibration level of the tire at the first rotational speed being level one vibration, the point cloud map is divided into several detection intervals along the tire circumference with a preset length, and each detection interval is configured with n mutually independent detection point sets.

[0053] Step S5: Collect the first set of detection points in each detection interval at the second rotation speed. After the first set of detection points is collected, collect the second set of detection points in each detection interval, and so on, until all sets of detection points are collected. Generate a second tire surface height point cloud map based on the measured tire surface height.

[0054] Step S6: Reduce the tire speed at a preset rate within a preset time, continuously collect the tire surface height within the first set of detection points, obtain the change in tire surface height, calculate the stability score, and determine whether the stability of the detection device meets the requirements based on the stability score.

[0055] Step S7: In response to the stability of the detection device meeting the requirements, the tire surface is rendered to generate a second visual point cloud map based on the second tire surface height point cloud map and the preset color matching mechanism, and the abnormal vibration level of the tire at the second rotation speed is determined in combination with the second preset standard.

[0056] Wherein: the first speed is less than the second speed.

[0057] In practice, the basic tire parameters include: circumference, width, and tire model. The testing device uses a laser scanning instrument to detect the surface height of the tire and a tire drive platform to rotate the tire.

[0058] In detail, during vehicle operation, due to factors such as turning, load, and tire age, different parts of the tire experience varying degrees of wear. Defects in the tire's geometry and structure can also cause vibrations during vehicle operation, in addition to vibrations caused by road bumps. These vibrations can lead to steering wheel vibration, vehicle body resonance, and driving noise, and in severe cases, can affect tire life and driving safety. By detecting the tire surface height and calculating the changes in tire surface height during rotation, we can understand that these changes generate periodic uneven centrifugal forces, which translate into vibrations. It is understood that the height difference is positively correlated with the vibration. Therefore, this embodiment of the invention calculates the height difference of the tire surface at each detection point and, based on the height difference and a preset color matching mechanism, renders the tire surface to generate a visual point cloud map, thus providing a direct and visual representation of the vibrations caused by the tire surface height.

[0059] Furthermore, basic tire parameters are obtained, and several detection points are set based on these parameters to generate a point cloud map, including:

[0060] Select an initial point at the center of the tire crown; this initial point is used to reference whether the tire has rotated one revolution during the tire inspection process.

[0061] Starting from the initial point, several detection points are evenly distributed along the tire circumference at a first interval, and several detection points are evenly distributed along the tire transverse direction at a second interval.

[0062] A point cloud map is generated based on several detection points.

[0063] In implementation, initial points are selected by marking the center of the tire crown with a white marker. The values ​​of the first and second spacings are determined based on the computing power of the data processing computer, the required accuracy of the detection results, or other parameters, and the values ​​should meet the actual situation. In this embodiment of the invention, the range of the first spacing is 1-2 mm, and the range of the second spacing is 0.5-1 mm. The specific values ​​are determined according to the actual situation of the tire, as long as the detection points are evenly distributed. All detection points are acquired using a laser scanning device, and a point cloud map is generated using Cloud-Compare software.

[0064] Furthermore, the tire surface height at each detection point is collected at the first rotational speed, and a first tire surface height point cloud map is generated, including:

[0065] Obtain the distance between detection points along the tire circumference and record it as the circumferential distance;

[0066] The detection frequency of the detection device is adjusted according to the circumferential spacing and the first rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference, ensuring that the detection device will collect the tire surface height once every time the tire rotates a distance of one first spacing in the circumferential direction.

[0067] The tire surface height at each detection point is collected at the first rotational speed;

[0068] The tire surface height at each detection point is matched with the point cloud image to generate the first tire surface height point cloud map.

[0069] Furthermore, along the tire circumference, the tire surface height point cloud map is divided into several detection intervals with a preset length. Each detection interval is configured with n independent sets of detection points, and each set of detection points includes several detection points in the same lateral direction.

[0070] The preset length is an integer multiple of the first spacing.

[0071] In implementation, the preset length is set to four times the first spacing, meaning that the tire surface height is collected at all monitoring points after the tire has rotated four times. The values ​​of the first and second rotation speeds are determined based on actual conditions, and the selected rotation speeds only need to meet the actual requirements and conditions. In this embodiment of the invention, the first rotation speed is set to 2 r / min, and the second rotation speed is set to 70 r / min.

[0072] In detail, considering that the scanning frequency and power of the laser scanning equipment gradually increase with the tire rotation speed, if we want to simulate the vibration of a car tire at 60-100 km / h, the tire rotation speed even needs to reach 50-80 r / min. The scanning frequency and power required for the detection device to scan the tire surface height at all detection points in one revolution are extremely high. This invention divides the tire surface height point cloud map into several detection intervals in the tire circumference. Each detection interval is configured with 4 independent detection point sets, and each detection point set includes several detection points in the same lateral direction. This means that for each revolution of the tire, only the first detection point set in different detection intervals is collected. After one revolution, the second detection point set in different detection intervals is collected. This eliminates the need for the detection device to collect the tire surface height at all detection points in one revolution of the tire, thereby reducing the power requirement of the detection device during the detection process. Furthermore, due to the initial point setting and the matching of rotation speed and scanning frequency, the accuracy and completeness of the detection point data collection are ensured, providing an accurate data basis for subsequent height difference calculation and tire surface rendering.

[0073] Furthermore, a first set of detection points is collected for each detection interval at a second rotational speed. After the first set of detection points is collected, a second set of detection points is collected for each detection interval, and so on, until all sets of detection points are collected. Based on the measured tire surface height, a second tire surface height point cloud map is generated, including:

[0074] The detection frequency of the detection device is adjusted according to the circumferential spacing and the second rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference.

[0075] In response to the start of the inspection, starting from the initial point, the first set of inspection points in all inspection intervals is collected within one revolution of the tire.

[0076] In response to the completion of the first set of detection points in all detection intervals, a new initial point is selected in the next detection interval of the current initial point. Starting from the newly selected initial point, the second set of detection points in all detection intervals is collected within one revolution of the tire. This process continues until all sets of detection points have been detected.

[0077] Wherein: the distance between the reselected initial point and the current initial point is a preset length;

[0078] The next detection interval after the current initial point is the next detection interval that needs to be collected as the tire rotates.

[0079] In detail, by collecting only the nth detection point set within different detection intervals, and then collecting the (n+1)th detection point set within different detection intervals after one cycle, the energy consumption of the detection device during the detection process is reduced. However, if the (n+1)th detection point set is immediately detected in the same detection interval after all the nth detection point sets in all detection intervals have been detected, the required interval time between the (n+1)th and nth detection point sets will be extremely small. This requires the detection frequency of the detection device to increase rapidly at this instant, causing a sudden increase in the power of the detection device. Therefore, in this embodiment of the invention, after collecting one cycle, the detection begins with the (n+1)th detection point set of the next detection interval to avoid a sudden increase in power and increase the service life of the detection device.

[0080] Furthermore, the stability score is calculated by obtaining information on changes in tire surface height, including:

[0081] Within a preset time, the tire speed is reduced at a preset rate, and the tire surface height and lateral offset of each detection point in the first set of detection points are continuously collected.

[0082] For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the surface height. The tire surface height curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed tire surface height curve is obtained and recorded as the height curvature.

[0083] For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the lateral offset. The tire lateral offset curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed lateral offset curve is obtained and recorded as the lateral curvature.

[0084] During the tire speed reduction process, corresponding weight coefficients are assigned to the height curvature and the lateral curvature respectively. The sum of the products of the height curvature and the lateral curvature and the corresponding weight coefficients is calculated and recorded as the stability score corresponding to each tire speed.

[0085] Stability variation curves are plotted based on tire speed and corresponding stability scores.

[0086] It should be noted that the weighting coefficients are assigned by computer, and the assigned weights are sufficient to ensure that the calculated stability score represents the stability of the detection device, with the sum of all weighting coefficients being 1. In this embodiment, the height curvature weighting coefficient is 0.4, and the lateral curvature weighting coefficient is 0.6. Since the tire speed gradually decreases according to a preset rate, the detection frequency of the corresponding detection device must also be adjusted accordingly to collect the tire surface height at each detection point. Therefore, the preset rate needs to be determined based on the frequency adjustment speed of the detection device; in practice, the preset rate is 20 r / min. The preset time is selected based on the calculation capability of the detection device, choosing the minimum time length that the detection device can select while satisfying stability requirements. In this embodiment, the preset time is 2 min. A Cartesian coordinate system is established with tire speed as the x-axis and stability score as the y-axis, and the stability change curve is plotted.

[0087] Understandably, regarding tire surface height curvature, the effect of centrifugal force on the tire surface height is significant. The higher the centrifugal force, the more pronounced the change in tire surface height. The change in surface height is positively correlated with the centrifugal force. As the rotational speed gradually decreases, the centrifugal force gradually decreases, and the surface height gradually decreases. The change in surface height with rotational speed will present a curve. Through a limited number of experiments, the curvature range of this curve corresponding to a qualified tire can be determined. If the testing device itself has a problem, it will cause the change in surface height with rotational speed to intensify. As the rotational speed increases or decreases, the vibration generated by the testing device will also increase or decrease. Due to the superposition of vibrations from the testing device, the curve will be more curved and have a greater curvature than the curve corresponding to when the testing device has no vibration. Therefore, the curvature of the tire surface height curve can reflect the stability of the testing device. Regarding lateral curvature, if the detection device itself has a bent shaft, a shaft off-center, or other causes that lead to lateral vibration of the tire, the vibration generated by the detection device will increase or decrease with the increase or decrease of the rotational speed. This will also cause the surface height to change more significantly with the rotational speed, resulting in an increase in the curve curvature. Therefore, the curvature of the lateral offset curve can also reflect the stability of the detection device. Since the weighting coefficients corresponding to the height curvature and lateral curvature are also determined, the range of stability scores corresponding to qualified tires can also be determined (i.e., the score range in this embodiment of the invention). Therefore, by assigning corresponding weighting coefficients to the height curvature and lateral curvature respectively and calculating the stability score, the stability of the detection device during the detection process can be judged, thereby verifying whether the measured tire surface height is accurate, and increasing the accuracy of identifying abnormal tire vibration through tire tread color difference.

[0088] Furthermore, the stability of the detection device is judged to meet the requirements based on the stability score. In response to the decrease in tire speed, if the stability score corresponding to the stability change curve of each detection point in the first detection point set is within the score range, the stability of the detection device is judged to meet the requirements.

[0089] In response to the fact that during the decrease in tire speed, the stability score corresponding to each detection point in the first detection point set is outside the score range on the stability change curve, it is determined that the stability of the detection device does not meet the requirements, and an equipment maintenance notice is issued to the maintenance personnel.

[0090] In this embodiment of the invention, the score range is (0.025, 0.04).

[0091] Furthermore, based on the first preset standard and the first visualized point cloud map, the abnormal vibration level of the tire at the first rotational speed is determined, including:

[0092] The highest and lowest points of the tire surface height in the first visualized point cloud map are obtained according to the preset color matching mechanism.

[0093] Calculate the height difference based on the highest and lowest points, and compare the height difference with a preset standard to obtain the vibration information.

[0094] In implementation, according to the preset color matching mechanism, the bright yellow position 1 is selected as the highest point of the tread, and the red and green position 2 is selected as the lowest point of the tread. The difference between position 1 and position 2 is calculated to be 0.85mm.

[0095] In detail, the first and second preset standards are selected based on actual needs, wherein:

[0096] The first preset standard is:

[0097] The difference between position 1 and position 2 is 0mm to 0.5mm, and the abnormal vibration level is determined to be Level 1 vibration;

[0098] The difference between position 1 and position 2 is 0.5mm to 1mm, and the abnormal vibration level is determined to be level two vibration;

[0099] The difference between position 1 and position 2 is 1mm to 1.5mm, and the abnormal vibration level is determined to be level three vibration;

[0100] If the difference between position 1 and position 2 is greater than 1.5mm, the abnormal vibration level is determined to be level four vibration.

[0101] Among them: Level 1 vibration is good, Level 2 vibration is slight and not easily noticeable, Level 3 vibration is relatively serious and affects the driving experience, and Level 4 vibration indicates that the vibration that occurs during the car's operation may affect driving safety.

[0102] Furthermore, based on the second tire surface height point cloud map and a preset color matching mechanism, the tire surface is rendered to generate a second visual point cloud map. Combined with a second preset standard, the abnormal vibration level of the tire at the second rotational speed is determined, including:

[0103] The highest and lowest points of the tire surface height in the second visualized point cloud map are obtained according to the preset color matching mechanism.

[0104] Calculate the height difference based on the highest and lowest points, and compare the height difference with a preset standard to obtain the vibration information.

[0105] In implementation, according to the preset color matching mechanism, the bright yellow position 1 is selected as the highest point of the tread, and the red and green position 2 is selected as the lowest point of the tread. The difference between position 1 and position 2 is calculated to be 0.55mm.

[0106] The second pre-set standard is:

[0107] The difference between position 1 and position 2 is 0mm to 0.3mm, and the abnormal vibration level is determined to be Level 1 vibration;

[0108] The difference between position 1 and position 2 is 0.3mm to 0.6mm, and the abnormal vibration level is determined to be level two vibration;

[0109] The difference between position 1 and position 2 is 0.6mm to 1.2mm, and the abnormal vibration level is determined to be level three vibration;

[0110] If the difference between position 1 and position 2 is greater than 1.2mm, the abnormal vibration level is determined to be level four vibration.

[0111] The vibration levels are as follows: Level 1 vibration is normal when the car tire reaches the second speed; Level 2 vibration is slight and barely noticeable when the car tire reaches the second speed; Level 3 vibration is relatively severe when the car tire reaches the second speed, affecting the driving experience; and Level 4 vibration indicates that the vibration occurring when the car tire reaches the second speed may affect driving safety.

[0112] Furthermore, a preset color matching mechanism divides the tire surface height into five intervals based on six interval points. The color of each interval point is assigned to one of six colors: black, blue, green, red, yellow, and white. The changes in tire surface height between interval points are represented by color gradients. The specific operation of the color matching mechanism is existing technology and will not be elaborated upon here.

[0113] Furthermore, in response to the presence of missing data in the detection point set, the data acquisition of subsequent detection points is immediately stopped, and the detection point set is re-acquired starting from the current initial point and the laser power is increased according to the preset amplitude.

[0114] In response to the fact that the power adjustment was performed twice and there was a data gap in the detection point set, it was determined that there was damage in the area corresponding to the detection point set, and the detection point set was marked.

[0115] In practice, the value of the preset amplitude is determined according to actual needs and the power limit of the detection device. In this embodiment of the invention, the value of the preset amplitude is 10% of the maximum power.

[0116] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for identifying abnormal tire vibration by measuring the color difference of the tire tread, characterized in that, include: Obtain basic tire parameters, set several detection points based on the basic tire parameters, and generate a point cloud map; The tire surface height at each detection point is collected at the first rotation speed, and a first tire surface height point cloud map is generated. Based on the first tire surface height point cloud map and the preset color matching mechanism, the tire surface is rendered to generate a first visual point cloud map, and the abnormal vibration level of the tire at the first rotational speed is determined according to the first preset standard and the first visual point cloud map. In response to the abnormal vibration level of the tire at the first rotational speed being level one vibration, the point cloud map is divided into several detection intervals along the tire circumference with a preset length, and each detection interval is configured with n mutually independent sets of detection points. The first set of detection points in each detection interval is collected at the second rotation speed. After the first set of detection points is collected, the second set of detection points in each detection interval is collected, and so on, until all sets of detection points are collected. A second tire surface height point cloud map is generated based on the measured tire surface height. Within a preset time, the tire speed is reduced at a preset rate, and the tire surface height within the first set of detection points is continuously collected. The change in tire surface height is obtained to calculate the stability score, and the stability of the detection device is determined based on the stability score. In response to the stability of the detection device meeting the requirements, the tire surface is rendered to generate a second visual point cloud map based on the second tire surface height point cloud map and the preset color matching mechanism, and the abnormal vibration level of the tire at the second rotational speed is determined in combination with the second preset standard. Wherein: the first rotational speed is less than the second rotational speed.

2. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 1, characterized in that, The process of acquiring basic tire parameters, setting several detection points based on these parameters, and generating a point cloud map includes: An initial point is selected at the center of the tire crown; this initial point is used to reference whether the tire rotates one revolution during the tire inspection process. Starting from the initial point, several detection points are evenly distributed along the tire circumference at a first interval, and several detection points are evenly distributed along the tire transverse direction at a second interval. The point cloud map is generated based on the aforementioned detection points.

3. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 2, characterized in that, The step of acquiring the tire surface height at each detection point at a first rotational speed and generating a first tire surface height point cloud map includes: Obtain the distance between detection points along the tire circumference and record it as the circumferential distance; The detection frequency of the detection device is adjusted according to the circumferential spacing and the first rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference. The tire surface height at each detection point is collected at the first rotational speed; The tire surface height at each detection point is matched with the point cloud image to generate a first tire surface height point cloud map.

4. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 3, characterized in that, Along the tire circumference, the point cloud map is divided into several detection intervals with a preset length. Each detection interval is configured with n independent sets of detection points, and each set of detection points includes several detection points in the same lateral direction. The preset length is an integer multiple of the first spacing.

5. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 4, characterized in that, The process involves acquiring a first set of detection points for each detection interval at a second rotational speed. After acquiring the first set of detection points, a second set of detection points is acquired for each detection interval, and so on, until all sets of detection points have been acquired. Based on the measured tire surface height, a second tire surface height point cloud map is generated, including: The detection frequency of the detection device is adjusted according to the circumferential spacing and the second rotation speed so that the detection frequency of the detection device matches the time required for the detection point to travel one axial spacing along the circumference. In response to the start of the detection, starting from the initial point, the first set of detection points in all detection intervals is collected within one revolution of the tire. In response to the completion of the first set of detection points in all detection intervals, a new initial point is selected in the next detection interval of the current initial point. Starting from the newly selected initial point, the second set of detection points in all detection intervals is collected within one revolution of the tire. This process continues until all sets of detection points have been detected. Wherein: the distance between the reselected initial point and the current initial point is the preset length.

6. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 1, characterized in that, The calculation of the stability score based on the change in tire surface height includes: Within a preset time, the tire speed is reduced at a preset rate, and the tire surface height and lateral offset corresponding to each detection point in the first set of detection points are continuously collected. For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the surface height. The tire surface height curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed tire surface height curve is obtained and recorded as the height curvature. For each detection point, a Cartesian coordinate system is established with the horizontal axis representing the rotational speed and the vertical axis representing the lateral offset. The tire lateral offset curve is plotted in the Cartesian coordinate system and smoothed. The curvature corresponding to each preset tire rotational speed of the smoothed lateral offset curve is obtained and recorded as the lateral curvature. During the tire speed reduction process, the height curvature and the lateral curvature corresponding to each preset tire speed are assigned corresponding weight coefficients. The sum of the products of the height curvature and the lateral curvature and the corresponding weight coefficients is calculated and recorded as the stability score corresponding to each tire speed. Stability variation curves are plotted based on tire speed and corresponding stability scores.

7. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 6, characterized in that, The determination of whether the stability of the detection device meets the requirements based on the stability score is made in response to the fact that, during the process of tire speed reduction, the stability scores corresponding to the stability change curves of each detection point in the first set of detection points are all within the score range, and the stability of the detection device is determined to meet the requirements.

8. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 1, characterized in that, The preset color matching mechanism divides the tire surface height into five intervals based on six interval points, and determines the color of each interval point as one of the six colors: black, blue, green, red, yellow, and white. The change in tire surface height is represented by the color gradient between the interval points.

9. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 8, characterized in that, The basic parameters of the tire include: circumference, width, and tire model.

10. The method for identifying abnormal tire vibration by means of tire tread color difference according to claim 9, characterized in that, In response to the presence of missing data in the detection point set, the data acquisition of subsequent detection points is immediately stopped, and the data acquisition of the detection point set is restarted from the current initial point, with the laser power increased according to the preset amplitude. In response to the fact that the power adjustment was performed twice and there was a data gap in the detection point set, it was determined that there was damage in the area corresponding to the detection point set, and the detection point set was marked.

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