Research On The Key Echniques Of Thread General Measurement

The requirement of is increasing in fields of modern mechanical and industrial production. Domestic and international research people have carried out plenty of researches on the measurement of threads detection for years, but the problems that efficiency is low and error of system is large exist still. In recent years, the technology of the machine visual image handing with CCD and computer is ripening gradually, and it has the advantage of accurate, fast and reliable. How to apply the machine visual to the field of the threads detection, and how to make the technology of threads detection more automatic and higher precision, are problems needed to solve urgently now.In this paper, a kind of new thread multi-parameter measure system based on image measurement has been designed, which substitute the " three ball method " for traditional measure ball, and , the advantage of the system has been .In this paper , parts of an apparatus of system are choosed and configuration is completed. According to the suitable object of program, in this paper, the software system of measure system has been designed, every modular can realize measure function and the control of own function and coordinative working complete entire system independently.How to get and handle threads tooth type outline, select histogram balance to melt and edge maintenance strain the original image of wave for collection carry out pretreatment, get the thread image that easily are analysised. Combined some edge detection and inferior pixel edge location, Hough alternate the straight line with least-square worthwhile method is put forward, which rather approach the thread edge of straight line .The round coordinate of center of a circle of system measures foundation is calculated, based on the straight line. According with national standard thread parameter definition and considering the round coordinate of center of a circle and the influence of thread liter angle, each parameter of thread in the calculation of this measure system expression is deduced, which is to hand each thread parameter measured voluntarily .Finally, the systematic source of error is analyzed and actual measure experiment is carried out. The results show that repeatability precision of system is 1.2μm.