CN114964828A - A method and system for predicting tire uniformity by scanning and pressure distribution of finished tires - Google Patents

Abstract

The invention provides a method and a system for predicting tire uniformity of a finished tire through scanning and pressure distribution, wherein the method comprises the following steps: the method comprises the steps of obtaining tire point cloud data attributes, analyzing the point cloud data attributes, removing noise points to obtain an original 2D point cloud image, establishing a theoretical model reconstruction system and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, determining the shape and the volume of concave points or convex points of a tire deviating from the outline of a basic tire, establishing a quality and size distribution diagram, applying stress to the tread of the tire, obtaining a stress distribution model of the tread, and establishing a tire uniformity two-dimensional model based on the quality and size distribution diagram and the stress distribution diagram of the tread to perform uniformity test on the tire. The invention can predict the force and the force change generated when the tire rotates at different speeds without carrying out the traditional uniformity test by carrying out simulation and point cloud processing on the finished tire.

Description

A method and system for predicting tire uniformity of finished tires by scanning and pressure distribution

technical field

The invention relates to the technical field of uniformity test simulation of finished tires, in particular to a method and system for predicting tire uniformity of finished tires by scanning and pressure distribution.

Background technique

The tire is a ring-shaped elastic body composed of fibers, steel wires, rubber and other materials. Due to the production process and design factors, the tire is not completely uniform and symmetrical. This non-uniformity is mainly manifested in the size, force of the tire and uneven quality. Including: the radial force deviation (RFV) of the tire is the jumping force of the tire crown when the tire with a certain load rolls at a certain speed. The larger the radial force deviation, the worse the ride comfort of the car, which is easy to cause driver fatigue , Lateral force deviation (LFV) It mainly reflects the swing of the tire, the greater the lateral force deviation, the car will swing when driving, the driver can not grasp the steering wheel, affecting its handling stability, but also accelerate tire wear.

The uniformity of a tire is related to the symmetry of the tire's axis of rotation. As the tire rotates, non-uniformities in the tire structure create periodic force variations or shocks at the tire's axis of rotation. The vibrations caused by these force changes are transmitted through the suspension and can be felt in the seats and steering wheel.

Tire uniformity attributes are generally categorized as dimensional (or geometric), quality variables. Uniformity testing is generally evaluated by measuring the change in force generated by the rotation of the tire around it. Measurement method: Under the specified air pressure load, the tire is applied to the drum that simulates the road surface, the drum is rotated, and the SLIP angle and the roll angle (CAMBER) are kept at "0", and the rotation of the tire is detected. The magnitude of the force generated and the change of the force, including radial force, lateral force, tangential force. Generally, there are two methods for measuring tire non-uniformity: low-speed testing machines for factory use and high-speed testing machines for research use. However, due to the high precision and expensive equipment and high requirements for testing accuracy, a slight deviation of the tire during the assembly test will cause great errors. Therefore, how to predict tire uniformity without relying on precision equipment is an urgent solution for those skilled in the art. technical issues.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method and system for predicting the tire uniformity of the finished tire by scanning and pressure distribution. The present invention simulates the finished tire, and calculates the uneven distribution of size and quality that deviates from the baseline by means of point cloud processing. Combined with the tread stress distribution of the tire, it is possible to predict the magnitude and change of the force generated when the tire rotates at different speeds without the need for traditional uniformity testing.

The present invention improves the method for testing the uniformity of tires by traditional low-speed testing machines and high-speed testing machines used for research in the prior art. Since the testing equipment is precise and expensive and requires high testing accuracy, the tires are assembled and tested in the process of testing. A slight deviation from the middle will cause a huge error. The present invention calculates the uneven distribution of the size and quality that deviates from the baseline by means of point cloud processing. Combined with the tread stress distribution of the tire, the uniformity without the need for a testing machine is realized. The test can predict the magnitude and change of the force generated when the tire rotates at different speeds.

The invention improves the conventional method for measuring the uniformity of tires in the prior art: under the specified air pressure load, the tire is applied to the drum simulating the road surface, the drum is rotated, and the deflection angle and the roll angle are kept as "0" In the state of the tire rotation, the size of the force and the change of the force generated when the tire is rotated, including radial force, lateral force, and tangential force, but its detection efficiency is low, and it is not suitable for large-scale batch production. The tires are tested efficiently. The invention establishes a database by combining the low-speed and high-speed uniformity of the tires, and through the computing system, realizes no need for uniformity testing, predicts the change of tire force and the magnitude of vibration, and greatly improves the detection efficiency. .

In order to achieve the above object, the present invention provides the following technical solutions:

A method for predicting tire uniformity of finished tires by scanning and pressure distribution, characterized by comprising:

Step S1: obtaining tire point cloud data attributes, analyzing the point cloud data attributes, and removing noise points therein to obtain an original 2D point cloud image;

Step S2: Establish a theoretical model reconstruction and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, and determine the deviation of the tire from the basic tire profile based on the theoretical model reconstruction and the actual model reconstruction. Shape and volume of pits or bumps, and build mass and size distribution maps;

Step S3: applying stress to the tread of the tire, and obtaining a stress distribution model of the tread;

Step S4: Based on the mass and size distribution map and the stress distribution map of the tread, a two-dimensional model of tire uniformity is established to test the uniformity of the tire, and predict the tire rotation at different speeds. magnitude and variation of force.

In some embodiments of the present application, the step S2 further includes:

Rotate the pixel points in the original 2D point cloud image in parallel to obtain point cloud data, and make the straight line fitted according to the pixel points located on the tread of the tire in the point cloud data to be parallel to the horizontal X-axis;

According to the point cloud data, the gradient analysis method is applied to locate the concave point or the convex point;

The volume of the concave or convex point is calculated from the point cloud data using bilateral or unilateral measurements.

In some embodiments of the present application, the step S3 further includes:

acquiring stress data of the tread, and calculating the effective area of the tread based on the stress data of the tread;

dividing the stress of the tread into a plurality of stress intervals;

based on the stress interval and the stress data, calculating the stress distribution area of each of the stress intervals;

calculating the ratio of the stress distribution area of each of the stress intervals to the effective area, and obtaining the cumulative probability of the stress distribution in the stress interval;

The stress distribution model is obtained by calculating shape parameters and volume parameters in a Weber distribution function based on the stress data and the stress distribution cumulative probability.

In some embodiments of the present application, the pixel points in the original 2D point cloud image are rotated in parallel to obtain point cloud data so that the straight line fitted according to the pixel points located on the tread surface in the point cloud data is parallel to Horizontal X-axis, including:

A first straight line is obtained by performing straight line fitting according to the first pixel point set after removing edge pixels in the original 2D point cloud image, and the first rotation required to rotate the first straight line to be parallel to the horizontal X-axis is calculated angle, rotating the first pixel point set by the first rotation angle to obtain a first point cloud set;

Acquire a second rotation angle required to eliminate the influence of the concave or convex point according to the first point cloud set, and obtain some points in the first point cloud set that are culled from the concave or convex point and rotated the second point cloud set obtained by the second rotation angle;

Obtaining a third rotation angle required to eliminate the influence of interference points according to the second point cloud set;

The point cloud data is obtained by rotating the pixel points in the original 2D point cloud image by the first rotation angle, the second rotation angle and the third rotation angle respectively.

In order to achieve the above object, the present invention also provides a system for predicting tire uniformity of finished tires by scanning and pressure distribution, which is characterized by comprising:

an acquisition module, used for acquiring tire point cloud data attributes, analyzing the point cloud data attributes, and removing noise points therein to obtain the original 2D point cloud image;

A processing module, configured to establish a theoretical model reconstruction and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, and determine that the tire deviates from the base tire based on the theoretical model reconstruction and the actual model reconstruction The shape and volume of the concave or convex point of the contour, and the mass and size distribution map;

a test module for applying stress to the tread of the tire and obtaining a stress distribution model of the tread;

The analysis module is used to establish a two-dimensional model of tire uniformity based on the mass and size distribution map and the stress distribution map of the tread, to test the uniformity of the tire, and to predict the rotation of the tire at different speeds. The magnitude and variation of the force generated.

In some embodiments of the present application, the processing module is further configured to rotate the pixel points in the original 2D point cloud image in parallel to obtain point cloud data, and make the tires located in the tire according to the point cloud data The straight line fitted by the pixel points of the surface is parallel to the horizontal X-axis;

According to the point cloud data, the gradient analysis method is applied to locate the concave point or the convex point;

The volume of the concave or convex point is calculated from the point cloud data using bilateral or unilateral measurements.

In some embodiments of the present application, the test module is further configured to acquire stress data of the tread, and calculate the effective area of the tread based on the stress data of the tread;

dividing the stress of the tread into a plurality of stress intervals;

based on the stress interval and the stress data, calculating the stress distribution area of each of the stress intervals;

calculating the ratio of the stress distribution area of each of the stress intervals to the effective area, and obtaining the cumulative probability of the stress distribution in the stress interval;

The stress distribution model is obtained by calculating shape parameters and volume parameters in a Weber distribution function based on the stress data and the stress distribution cumulative probability.

In some embodiments of the present application, the processing module is further configured to perform straight line fitting according to the first set of pixel points in the original 2D point cloud image after the edge pixels are removed to obtain a first straight line, and calculate the first straight line. Rotate a line to the first rotation angle required to be parallel to the horizontal X-axis, and rotate the first pixel point set by the first rotation angle to obtain a first point cloud set;

Acquire a second rotation angle required to eliminate the influence of the concave or convex point according to the first point cloud set, and obtain some points in the first point cloud set that are culled from the concave or convex point and rotated the second point cloud set obtained by the second rotation angle;

Obtaining a third rotation angle required to eliminate the influence of interference points according to the second point cloud set;

The point cloud data is obtained by rotating the pixel points in the original 2D point cloud image by the first rotation angle, the second rotation angle and the third rotation angle respectively.

To achieve the above object, the present invention also provides a computer device, comprising a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program stored in the memory, the processor executes the computer program. The described method for predicting tire uniformity by scanning and pressure distribution of finished tires.

In order to achieve the above object, the present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the processor executes the process of scanning and pressure distribution of the finished tire. A method for predicting tire uniformity.

The present invention provides a method and system for predicting the uniformity of a finished tire by scanning and pressure distribution. Compared with the prior art, its beneficial effects are:

The invention obtains the attributes of tire point cloud data, analyzes the attributes of the point cloud data, and removes the noise points therein to obtain the original 2D point cloud image, and establishes a theoretical model reconstruction and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image. Based on theoretical model reconstruction and actual model reconstruction, determine the shape and volume of the concave or convex point that deviates from the basic tire profile, and establish the mass and size distribution map, apply stress to the tread of the tire, and obtain the stress distribution of the tread The model, based on the mass and size distribution map and the stress distribution map of the tread, establishes a two-dimensional model of tire uniformity to test the uniformity of the tire, and predict the size and change of the force generated by the tire during rotation at different speeds. The invention calculates the unevenness of tire geometric size and mass distribution by means of point cloud processing, analyzes the tread stress distribution by applying stress, correlates with the uniformity of low speed and high speed of the tire, and establishes a database, through the calculation system, Realize no need for uniformity test, predict the change of tire force and the magnitude of vibration, and realize efficient inspection of tires produced in large-scale batches.

Description of drawings

Fig. 1 is the flow chart of the method for predicting tire uniformity by scanning and pressure distribution of finished tire of the present invention;

FIG. 2 is a functional block diagram of the system of the present invention for predicting tire uniformity through scanning and pressure distribution in a finished tire.

Detailed ways

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

The terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of this application, unless stated otherwise, "plurality" means two or more.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be mechanical connection or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the connection between the inner sides of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

Tire uniformity attributes are generally categorized as dimensional (or geometric), quality variables. Uniformity testing is generally evaluated by measuring the change in force generated by the rotation of the tire around it. Measurement method: Under the specified air pressure load, the tire is applied to the drum that simulates the road surface, the drum is rotated, and the SLIP angle and the roll angle (CAMBER) are kept at "0", and the tire rotation is detected. The magnitude of the force generated and the change of the force, including radial force, lateral force, tangential force. Generally, there are two methods for measuring tire non-uniformity: low-speed testing machines for factory use and high-speed testing machines for research use. However, due to the high precision and expensive equipment and high requirements for testing accuracy, a slight deviation of the tire during the assembly test will cause great errors. Therefore, how to predict tire uniformity without relying on precision equipment is an urgent solution for those skilled in the art. technical issues.

Therefore, the present invention provides a method and system for predicting the tire uniformity of a finished tire by scanning and pressure distribution. By means of point cloud processing, the uneven distribution of size and mass deviating from the baseline is calculated, combined with the tread stress distribution of the tire, It is associated with the uniformity of low speed and high speed, establishes a database, and realizes no need for uniformity test through the calculation system, and predicts the magnitude of the force and the change of force generated when the tire rotates at different speeds.

Referring to Fig. 1, the present invention provides a method for predicting tire uniformity of a finished tire by scanning and pressure distribution, including:

Step S1: obtaining the attributes of the tire point cloud data, analyzing the point cloud data attributes, and removing noise points therein to obtain the original 2D point cloud image;

Step S2: Establish a theoretical model reconstruction and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, and determine the shape and shape of the concave or convex point that deviates from the basic tire profile based on the theoretical model reconstruction and the actual model reconstruction. volume, and establish mass and size distribution maps;

Step S3: applying stress to the tread of the tire, and obtaining a stress distribution model of the tread;

Step S4: Establish a two-dimensional tire uniformity model based on the mass and size distribution map and the stress distribution map of the tread to test the uniformity of the tire, and predict the magnitude and change of the force generated by the tire rotating at different speeds.

In a specific embodiment of the present application, step S2 further includes:

Rotate the pixel points in the original 2D point cloud image in parallel to obtain point cloud data, and make the straight line fitted according to the pixel points located on the tread of the tire in the point cloud data parallel to the horizontal X-axis;

Apply gradient analysis method to locate concave or convex points according to point cloud data;

Calculate the volume of concave or convex points by applying bilateral or unilateral measurements from point cloud data.

Step S3 also includes:

Obtain the stress data of the tread, and calculate the effective area of the tread based on the stress data of the tread;

Divide the tread stress into multiple stress intervals;

Based on the stress interval and stress data, calculate the stress distribution area of each stress interval;

Calculate the ratio of the stress distribution area to the effective area of each stress interval, and obtain the cumulative probability of stress distribution in the stress interval;

The shape parameters and volume parameters in the Weber distribution function are calculated based on the stress data and the cumulative probability of the stress distribution, and the stress distribution model is obtained.

The beneficial effect is that: by establishing a mathematical model and numerical values to reflect the distribution law and concentration effect of stress respectively, the stress distribution law and concentration effect exerted on the tire surface can be reflected more intuitively and objectively, and the stress distribution model can be more intuitive and accurate. Obtain relevant data on the tread uniformity of the tire.

Rotate the pixel points in the original 2D point cloud image in parallel to obtain point cloud data so that the straight line fitted according to the pixel points located on the tread surface in the point cloud data is parallel to the horizontal X axis, including:

The first straight line is obtained by straight-line fitting according to the first set of pixels in the original 2D point cloud image after the edge pixels are removed, and the first rotation angle required to rotate the first straight line to be parallel to the horizontal X-axis is calculated. A pixel point set is rotated by a first rotation angle to obtain a first point cloud set;

Obtain the second rotation angle required to eliminate the influence of the concave or convex points according to the first point cloud set, and obtain the second rotation angle obtained by removing the concave or convex points in the first point cloud set and rotating the second rotation angle point cloud collection;

Obtain the third rotation angle required to eliminate the influence of the interference point according to the second point cloud set;

Rotate the pixel points in the original 2D point cloud image by the first rotation angle, the second rotation angle and the third rotation angle respectively to obtain point cloud data.

The beneficial effect is that: the pixels in the original 2D point cloud image are rotated by the first rotation angle α to make the overall trend of the rotated pixels parallel to the horizontal X-axis, and the influence of concave or convex points can be eliminated by rotating the second rotation angle β. , by rotating the third rotation angle γ, the influence of the interference point caused by the deviation of the tire from the base tire can be further eliminated, and the finally obtained point cloud data tends to be parallel to the horizontal X axis, which can make the volume calculation of the concave or convex point more accurate. Precise.

Based on the same technical concept, referring to FIG. 2 , the present invention also provides a system for predicting tire uniformity of finished tires by scanning and pressure distribution, including:

The acquisition module is used to acquire tire point cloud data attributes, analyze the point cloud data attributes, and remove the noise points to obtain the original 2D point cloud image;

The processing module is used to establish a theoretical model reconstruction and an actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, and based on the theoretical model reconstruction and actual model reconstruction, determine the concave or convex points of the tire that deviate from the basic tire contour. shape and volume, and build mass and size distribution maps;

The test module is used to apply stress to the tread of the tire and obtain the stress distribution model of the tread;

The analysis module is used to establish a two-dimensional model of tire uniformity based on the mass and size distribution map and the stress distribution map of the tread, to test the uniformity of the tire, and to predict the size and change of the force generated by the tire rotating at different speeds.

In a specific embodiment of the present application, the processing module is further configured to rotate the pixel points in the original 2D point cloud image in parallel to obtain point cloud data, and fit the pixel points located on the tread of the tire according to the point cloud data. The line is parallel to the horizontal X axis;

Apply gradient analysis method to locate concave or convex points according to point cloud data;

Calculate the volume of concave or convex points by applying bilateral or unilateral measurements from point cloud data.

The test module is also used to obtain the stress data of the tread, and calculate the effective area of the tread based on the stress data of the tread;

Divide the tread stress into multiple stress intervals;

Based on the stress interval and stress data, calculate the stress distribution area of each stress interval;

Calculate the ratio of the stress distribution area to the effective area of each stress interval, and obtain the cumulative probability of stress distribution in the stress interval;

The shape parameters and volume parameters in the Weber distribution function are calculated based on the stress data and the cumulative probability of the stress distribution, and the stress distribution model is obtained.

The beneficial effect is that: by establishing a mathematical model and numerical values to reflect the distribution law and concentration effect of stress respectively, the stress distribution law and concentration effect exerted on the tire surface can be reflected more intuitively and objectively, and the stress distribution model can be more intuitive and accurate. Obtain relevant data on the tread uniformity of the tire.

The processing module is further configured to perform straight line fitting according to the first pixel point set after culling edge pixels in the original 2D point cloud image to obtain the first straight line, and calculate the first straight line required to rotate the first straight line to be parallel to the horizontal X-axis. Rotation angle, rotate the first pixel point set by the first rotation angle to obtain the first point cloud set;

Obtain the second rotation angle required to eliminate the influence of the concave or convex points according to the first point cloud set, and obtain the second rotation angle obtained by removing the concave or convex points in the first point cloud set and rotating the second rotation angle point cloud collection;

Obtain the third rotation angle required to eliminate the influence of the interference point according to the second point cloud set;

Rotate the pixel points in the original 2D point cloud image by the first rotation angle, the second rotation angle and the third rotation angle respectively to obtain point cloud data.

The beneficial effect is that: the pixels in the original 2D point cloud image are rotated by the first rotation angle α to make the overall trend of the rotated pixels parallel to the horizontal X-axis, and the influence of concave or convex points can be eliminated by rotating the second rotation angle β. , by rotating the third rotation angle γ, the influence of the interference point caused by the deviation of the tire from the base tire can be further eliminated, and the finally obtained point cloud data tends to be parallel to the horizontal X axis, which can make the volume calculation of the concave or convex point more accurate. Precise.

Based on the same technical concept, the disclosed embodiments of the present invention also provide a computer device, including a memory and a processor, where a computer program is stored in the memory, and when the processor executes the computer program stored in the memory, The processor executes the method for predicting tire uniformity by scanning and pressure distribution of a finished tire.

The computing device may include a processor, a communication interface, a memory, and a communication bus. The processor, the communication interface, and the memory communicate with each other through a communication bus. The communication interface is used to communicate with network elements of other devices such as clients or other servers. The processor is configured to execute a program, and is specifically configured to execute relevant steps in the embodiment of the method for predicting the uniformity of the tire by scanning and the pressure distribution of the finished tire.

Based on the same technical concept, the disclosed embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes the finished tire. A method for predicting tire uniformity by scanning and pressure distribution.

According to the first concept of the present invention, the present invention calculates the uneven distribution of size and mass deviating from the baseline by means of point cloud processing, combined with the tread stress distribution of the tire, realizes that the uniformity test can be predicted without the need for a testing machine. The magnitude and change of the force generated when the tire rotates at different speeds.

According to the second concept of the present invention, the present invention establishes a database by combining the low-speed and high-speed uniformity of the tire and establishes a database. Through the calculation system, the uniformity test is not required to predict the change of tire force and the magnitude of vibration, which greatly improves the detection efficiency.

To sum up, the present invention provides a method and system for predicting tire uniformity of finished tires by scanning and pressure distribution. By simulating the finished tires and processing point clouds, the size and quality unevenness deviating from the baseline are calculated. Combined with the tread stress distribution of the tire, it is possible to predict the magnitude and change of the force generated when the tire rotates at different speeds without the need for traditional uniformity testing.

The above is only an embodiment of the present invention, but it cannot limit the scope of the present invention. Any structural changes made according to the present invention should be regarded as falling within the scope of the present invention as long as the essence of the present invention is not lost. be restricted within the scope of protection of the invention.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, for the specific working process and related description of the system described above, reference may be made to the corresponding process in the foregoing method embodiments, which will not be repeated here.

It should be noted that, the system provided by the above-mentioned embodiments is only illustrated by the division of the above-mentioned functional modules. The modules or steps in the above can be decomposed or combined. For example, the modules in the above embodiments can be combined into one module, or can be further split into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing each module or step, and should not be regarded as an improper limitation of the present invention.

Those skilled in the art should be aware that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two, and the programs corresponding to the software modules and method steps Can be placed in random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or as known in the art in any other form of storage medium. In order to clearly illustrate the interchangeability of electronic hardware and software, the components and steps of each example have been described generally in terms of functionality in the foregoing description. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods of implementing the described functionality for each particular application, but such implementations should not be considered beyond the scope of the present invention.

The term "comprising" or any other similar term is intended to encompass a non-exclusive inclusion such that a process, method, article or device/means comprising a list of elements includes not only those elements but also other elements not expressly listed, or Also included are elements inherent to these processes, methods, articles or devices/devices.

So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (10)

1. A method for predicting uniformity of a finished tire by scanning and pressure distribution, comprising:

step S1: acquiring tire point cloud data attributes, analyzing the point cloud data attributes, and removing noise points in the point cloud data attributes to obtain an original 2D point cloud picture;

step S2: establishing a theoretical model reconstruction and actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, determining the shape and the volume of a concave point or a convex point of the tire deviating from the outline of a basic tire based on the theoretical model reconstruction and the actual model reconstruction, and establishing a mass and size distribution diagram;

step S3: applying stress to the tread of the tire, and obtaining a stress distribution model of the tread;

step S4: and establishing a tire uniformity two-dimensional model based on the mass and dimension distribution map and the stress distribution map of the tread, carrying out uniformity test on the tire, and predicting the magnitude and the change of the force generated by the tire in rotation at different speeds.

2. The method for predicting the uniformity of a finished tire through scanning and pressure distribution as claimed in claim 1, wherein said step S2 further comprises:

performing parallel rotation on pixel points in the original 2D point cloud image to obtain point cloud data, and enabling a straight line fitted according to the pixel points positioned on the tire tread in the point cloud data to be parallel to a horizontal X axis;

positioning the concave points or the convex points by applying a gradient analysis method according to the point cloud data;

and calculating the volume of the concave points or the convex points by applying bilateral measurement or unilateral measurement according to the point cloud data.

3. The method for predicting tire uniformity through scanning and pressure distribution of a finished tire as claimed in claim 1, wherein said step S3 further comprises:

acquiring stress data of the tread, and calculating the effective area of the tread based on the stress data of the tread;

dividing the stress of the tread into a plurality of stress intervals;

calculating the stress distribution area of each stress interval based on the stress interval and the stress data;

calculating the proportion of the stress distribution area of each stress interval in the effective area to obtain the stress distribution cumulative probability in the stress interval;

and calculating shape parameters and volume parameters in a Weber distribution function based on the stress data and the stress distribution cumulative probability to obtain the stress distribution model.

4. The method of claim 2, wherein the step of performing parallel rotation on pixel points in the original 2D point cloud image to obtain point cloud data such that a straight line fitted to the pixel points on the surface of the tread in the point cloud data is parallel to a horizontal X-axis comprises:

performing straight line fitting according to a first pixel point set in the original 2D point cloud picture after edge pixel points are removed to obtain a first straight line, calculating a first rotation angle required by the first straight line rotating to be parallel to a horizontal X axis, and rotating the first pixel point set by the first rotation angle to obtain a first point cloud set;

acquiring a second rotation angle for eliminating the influence of the concave points or the convex points on rotation according to the first point cloud set, and acquiring a second point cloud set which is obtained by removing partial points of the concave points or the convex points from the first point cloud set and rotating the second rotation angle;

acquiring a third rotation angle required to rotate for eliminating the influence of the interference points according to the second point cloud set;

and respectively rotating the pixel points in the original 2D point cloud picture by the first rotation angle, the second rotation angle and the third rotation angle to obtain the point cloud data.

5. A system for predicting uniformity of a finished tire from a scan and pressure profile, comprising:

the acquisition module is used for acquiring the tire point cloud data attribute, analyzing the point cloud data attribute and removing noise points in the point cloud data attribute to obtain an original 2D point cloud picture;

the processing module is used for establishing a theoretical model reconstruction and actual model reconstruction system based on the point cloud data attributes and the original 2D point cloud image, determining the shape and the volume of a concave point or a convex point of the tire deviating from the outline of a basic tire based on the theoretical model reconstruction and the actual model reconstruction, and establishing a quality and size distribution map;

the testing module is used for applying stress to the tire tread of the tire and obtaining a stress distribution model of the tire tread;

and the analysis module is used for establishing a tire uniformity two-dimensional model based on the mass and dimension distribution map and the stress distribution map of the tread to perform uniformity test on the tire and predicting the magnitude and the change of the force generated by the tire during rotation at different speeds.

6. A system for predicting uniformity of a finished tire from a scan and pressure profile as claimed in claim 5,

the processing module is further used for carrying out parallel rotation on pixel points in the original 2D point cloud image to obtain point cloud data, and enabling straight lines fitted according to the pixel points located on the tire tread in the point cloud data to be parallel to a horizontal X axis;

positioning the concave points or the convex points by applying a gradient analysis method according to the point cloud data;

and calculating the volume of the concave points or the convex points by applying bilateral measurement or unilateral measurement according to the point cloud data.

7. A system for predicting uniformity of a finished tire from a scan and pressure profile as claimed in claim 5,

the testing module is also used for acquiring stress data of the tread and calculating the effective area of the tread based on the stress data of the tread;

dividing the stress of the tread into a plurality of stress intervals;

calculating the stress distribution area of each stress interval based on the stress interval and the stress data;

calculating the proportion of the stress distribution area of each stress interval in the effective area to obtain the stress distribution cumulative probability in the stress interval;

and calculating shape parameters and volume parameters in a Weber distribution function based on the stress data and the stress distribution cumulative probability to obtain the stress distribution model.

8. A system for predicting uniformity of a finished tire from a scan and pressure profile as claimed in claim 6,

the processing module is further used for performing straight line fitting according to a first pixel point set in the original 2D point cloud picture after edge pixel points are removed to obtain a first straight line, calculating a first rotation angle required by the first straight line rotating to be parallel to a horizontal X axis, and rotating the first pixel point set by the first rotation angle to obtain a first point cloud set;

acquiring a second rotation angle for eliminating the influence of the concave points or the convex points on rotation according to the first point cloud set, and acquiring a second point cloud set which is obtained by removing partial points of the concave points or the convex points from the first point cloud set and rotating the second rotation angle;

acquiring a third rotation angle for eliminating the influence of the interference points on the rotation according to the second point cloud set;

and respectively rotating the pixel points in the original 2D point cloud picture by the first rotation angle, the second rotation angle and the third rotation angle to obtain the point cloud data.

9. A computer apparatus comprising a memory and a processor, the memory having a computer program stored therein, the processor when executing the computer program stored in the memory performing the method of predicting tire uniformity from a scan and pressure profile of a finished tire as claimed in any one of claims 1-4.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out a method for predicting the uniformity of a tyre through scanning and pressure distribution of a finished tyre according to any one of claims 1 to 4.

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