| For the measurement of large-sized and complex surface structured all-steel radial tire cross-sections,most tire manufacturers still rely on the traditional method of manual measurement.This method excessively relies on workers’ experience and operation,which results in poor measurement repeatability and low measurement efficiency.To solve this problem,this paper studies the structure and measurement parameters of all-steel radial tires,which designs algorithms for measuring the length of the inner contour and recognizes the reference points of the outer contour.At the same time,the design and implementation of the tire cross-section measurement system are completed,which improves measurement efficiency and simplifies measurement steps.The main research contents and innovations of this paper are as follows:(1)This paper constructs a large-scale image acquisition platform which based on the Contact Image Sensor(CIS),lighting system,and servo system.For the usage scenario of the all-steel radial tire cross-section,the externally synchronized trigger mode of the CIS linear array camera is selected to obtain large-sized high-resolution images.Compared with the traditional method of fusing multiple images into a large-sized image,this accuracy of the image is improved and the error caused by image merging is reduced.In order to precisely control the movement of the motor,the Programmable Logic Controller(PLC)is selected as the control core to achieve stable control of the CIS linear array camera’s motion,opening and closing of the loading platform.At the same time,the structure of the PLC in the system is studied and the functional program implemented by the PLC is designed to ensure the stable operation of the system.(2)To achieve the function of automatically calculating the length of the inner contour of the tire cross-section,an measurement algorithm based on the chain code tracking method is designed,which improves the calculation efficiency and the accuracy error is 1mm.In order to obtain the reference points of the outer contour,the K-cosine curvature algorithm is improved based on the characteristics of concave and convex angles to identify the corner points of the outer contour of the tire side.At the same time,according to the feature that the position of adjacent reference point is adjacent,the position difference of adjacent corner points is calculated and the threshold is used to successfully screen the position of the reference points,which simplifies the step of selecting measurement parameters.(3)To ensure the accuracy of the measurement results of the all-steel radial tire crosssection,a calibration algorithm is used to determine whether the resolution is correct.At the same time,the software design is carried out for the measurement parameters and measurement of tire section parameters and automatic calculation of the inner contour circumference are realized.Then through system testing,the measurement accuracy error of the parameters is within 0.5mm,which meets the accuracy requirements of the measurement. |
