| Recently,with the rapid development of China's economy,car inventory has been increasing,the safety of automobiles has become one of the most concerned issues,and the braking system of automobiles plays a vital role in its safety performance,especially the core component of automobile brake system-brake master cylinder,its quality is closely related to the braking effect and directly affects the safety of driving.Quality test of brake master cylinder includes compensation hole size parameters,internal surface quality,performance test,etc.among them,the compensation hole size parameters and inner surface quality are the key to the performance of the brake master cylinder,in the brake master cylinder manufacturer,the inspection in the hole before delivery is an indispensable inspection item.Up to now,the online detection of compensation hole of brake master cylinder is still a cutting-edge detection technology,and the existing conventional detection methods cannot meet the growing requirements of detection.Aiming at the low accuracy,high cost and low efficiency of compensation hole detection of brake master cylinder,the laboratory puts forward the high-performance precision detection scheme of integration of light,machine and electricity,the scheme is based on mechanical transmission,the CCD camera technology is used to obtain the image of the brake master cylinder compensation hole,and the real-time image processing is used to realize the online detection of compensation hole of the brake master cylinder.This paper is based on the test prototype of "automobile brake master cylinder compensation hole photoelectric detection system" independently developed by the laboratory,in order to reduce detection errors and improve detection accuracy,the identification and compensation of error sources in the detection process were studied,at the same time,the double telecentric optical system is designed,the image processing technologies such as image preprocessing and image edge extraction in the detection principle are explored.The specific research contents are as follows:The geometrical errors and control system errors affecting the detection accuracy of the test prototype are discussed,and the error key items are simplified.At the same time,based on multi-body system theory and homogeneous coordinate transformation principle,the spatial integrated error model of the test prototype is established.The specific form of spatial geometric error is described.The geometric error identification of the translational axis and rotary axis of the test prototype is carried out.The geometric error identification model is established.At the same time,the geometric error of translational axis and rotary axis is carried out,and the incremental error compensation method is proposed based on the data characteristics of the geometric error.Aiming at the essential characteristics of brake master cylinder compensation hole detection,based on the basic principle of optical endoscopy,double telecentric optical system is designed,and the digital image processing technology involved in optical camera system is studied,and presents a smoothing method and gauss-laplacian operator suitable for the detection of images in this subject.Based on the error compensation research,a comprehensive error compensation scheme is proposed,and through physical modeling,the error compensation scheme is tested by contrast.The experimental data shows that the proposed comprehensive scheme can effectively reduce the geometric error of the test prototype,and greatly improve the test accuracy of the test prototype. |
PDF Full Text Request